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Farooq HMU, Yang L, Cao M, Chen Z, Qian A, Dang K. Recent Progress in the Research on RNA-Binding Proteins in Bone Development and Diseases. Int J Mol Sci 2024; 25:7735. [PMID: 39062974 PMCID: PMC11276800 DOI: 10.3390/ijms25147735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 07/06/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
RNA-binding proteins (RBPs), which regulate gene expression through post-transcriptional modifications of RNAs, play a role in diverse biological processes that include bone cell development and bone tissue formation. RBP dysregulation may result in aberrant bone homeostasis and contribute to various bone diseases. The function of RBPs in bone physiology and pathophysiology and the underlying molecular mechanisms have been extensively studied in recent years. This article provides a review of such studies, highlighting the potential of RBPs as pivotal targets for therapeutic intervention.
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Affiliation(s)
| | | | | | | | - Airong Qian
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China; (H.M.U.F.); (L.Y.); (Z.C.)
| | - Kai Dang
- Laboratory for Bone Metabolism, Xi’an Key Laboratory of Special Medicine and Health Engineering, Key Laboratory for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi’an 710072, China; (H.M.U.F.); (L.Y.); (Z.C.)
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Maroni P, Pesce NA, Lombardi G. RNA-binding proteins in bone pathophysiology. Front Cell Dev Biol 2024; 12:1412268. [PMID: 38966428 PMCID: PMC11222650 DOI: 10.3389/fcell.2024.1412268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Accepted: 06/04/2024] [Indexed: 07/06/2024] Open
Abstract
Bone remodelling is a highly regulated process that maintains mineral homeostasis and preserves bone integrity. During this process, intricate communication among all bone cells is required. Indeed, adapt to changing functional situations in the bone, the resorption activity of osteoclasts is tightly balanced with the bone formation activity of osteoblasts. Recent studies have reported that RNA Binding Proteins (RBPs) are involved in bone cell activity regulation. RBPs are critical effectors of gene expression and essential regulators of cell fate decision, due to their ability to bind and regulate the activity of cellular RNAs. Thus, a better understanding of these regulation mechanisms at molecular and cellular levels could generate new knowledge on the pathophysiologic conditions of bone. In this Review, we provide an overview of the basic properties and functions of selected RBPs, focusing on their physiological and pathological roles in the bone.
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Affiliation(s)
- Paola Maroni
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy
| | - Noemi Anna Pesce
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy
| | - Giovanni Lombardi
- Laboratory of Experimental Biochemistry and Molecular Biology, IRCCS Istituto Ortopedico Galeazzi, Milano, Italy
- Department of Athletics, Strength and Conditioning, Poznań University of Physical Education, Poznań, Poland
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Cesari E, Farini D, Medici V, Ehrmann I, Guerra M, Testa E, Naro C, Geloso MC, Pagliarini V, La Barbera L, D’Amelio M, Orsini T, Vecchioli SF, Tamagnone L, Fort P, Viscomi MT, Elliott DJ, Sette C. Differential expression of paralog RNA binding proteins establishes a dynamic splicing program required for normal cerebral cortex development. Nucleic Acids Res 2024; 52:4167-4184. [PMID: 38324473 PMCID: PMC11077083 DOI: 10.1093/nar/gkae071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 01/17/2024] [Accepted: 01/25/2024] [Indexed: 02/09/2024] Open
Abstract
Sam68 and SLM2 are paralog RNA binding proteins (RBPs) expressed in the cerebral cortex and display similar splicing activities. However, their relative functions during cortical development are unknown. We found that these RBPs exhibit an opposite expression pattern during development. Sam68 expression declines postnatally while SLM2 increases after birth, and this developmental pattern is reinforced by hierarchical control of Sam68 expression by SLM2. Analysis of Sam68:Slm2 double knockout (Sam68:Slm2dko) mice revealed hundreds of exons that respond to joint depletion of these proteins. Moreover, parallel analysis of single and double knockout cortices indicated that exons regulated mainly by SLM2 are characterized by a dynamic splicing pattern during development, whereas Sam68-dependent exons are spliced at relatively constant rates. Dynamic splicing of SLM2-sensitive exons is completely suppressed in the Sam68:Slm2dko developing cortex. Sam68:Slm2dko mice die perinatally with defects in neurogenesis and in neuronal differentiation, and develop a hydrocephalus, consistent with splicing alterations in genes related to these biological processes. Thus, our study reveals that developmental control of separate Sam68 and Slm2 paralog genes encoding homologous RBPs enables the orchestration of a dynamic splicing program needed for brain development and viability, while ensuring a robust redundant mechanism that supports proper cortical development.
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Affiliation(s)
- Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Donatella Farini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Vanessa Medici
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Ingrid Ehrmann
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Marika Guerra
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Erika Testa
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Maria Concetta Geloso
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
| | - Livia La Barbera
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
| | - Marcello D’Amelio
- Fondazione Santa Lucia IRCCS, Via del Fosso di Fiorano, 64, 00143 Rome, Italy
- Università Campus Bio-Medico di Roma, Via Álvaro del Portillo, 21, 00128 Rome, Italy
| | - Tiziana Orsini
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Stefano Farioli Vecchioli
- Institute of Biochemistry and Cell Biology, National Research Council (IBBC/CNR), Monterotondo, 00015 Rome, Italy
| | - Luca Tamagnone
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - Philippe Fort
- Centre de Recherche en Biologie Cellulaire de Montpellier, University of Montpellier, CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 05, France
| | - Maria Teresa Viscomi
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
- Department of Life Science and Public Health, Section of Histology and Embryology, Catholic University of the Sacred Heart, Rome
| | - David J Elliott
- Newcastle University Centre for Cancer, Newcastle University Institute of Biosciences, Newcastle NE1 3BZ, UK
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
- Fondazione Policlinico Agostino Gemelli IRCCS, Largo Agostino Gemelli, 00168 Rome, Italy
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Wu J, Niu L, Yang K, Xu J, Zhang D, Ling J, Xia P, Wu Y, Liu X, Liu J, Zhang J, Yu P. The role and mechanism of RNA-binding proteins in bone metabolism and osteoporosis. Ageing Res Rev 2024; 96:102234. [PMID: 38367813 DOI: 10.1016/j.arr.2024.102234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024]
Abstract
Osteoporosis is a prevalent chronic metabolic bone disease that poses a significant risk of fractures or mortality in elderly individuals. Its pathophysiological basis is often attributed to postmenopausal estrogen deficiency and natural aging, making the progression of primary osteoporosis among elderly people, especially older women, seemingly inevitable. The treatment and prevention of osteoporosis progression have been extensively discussed. Recently, as researchers delve deeper into the molecular biological mechanisms of bone remodeling, they have come to realize the crucial role of posttranscriptional gene control in bone metabolism homeostasis. RNA-binding proteins, as essential actors in posttranscriptional activities, may exert influence on osteoporosis progression by regulating the RNA life cycle. This review compiles recent findings on the involvement of RNA-binding proteins in abnormal bone metabolism in osteoporosis and describes the impact of some key RNA-binding proteins on bone metabolism regulation. Additionally, we explore the potential and rationale for modulating RNA-binding proteins as a means of treating osteoporosis, with an overview of drugs that target these proteins.
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Affiliation(s)
- Jiaqiang Wu
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China; Department of General Surgery, First Medical Center of the Chinese PLA General Hospital, Beijing, China
| | - Liyan Niu
- HuanKui College of Nanchang University, Nanchang 330006, China
| | - Kangping Yang
- The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China
| | - Jingdong Xu
- Queen Mary College of Nanchang University, Nanchang 330006, China
| | - Deju Zhang
- Food and Nutritional Sciences, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, 999077, Hong Kong, China
| | - Jitao Ling
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Panpan Xia
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Yuting Wu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Xiao Liu
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510275, China
| | - Jianping Liu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Jing Zhang
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; Department of Anesthesiology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, 330006, China.
| | - Peng Yu
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China.
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Verdile V, Palombo R, Ferrante G, Ferri A, Amadio S, Volonté C, Paronetto MP. Dysregulation of alternative splicing underlies synaptic defects in familial amyotrophic lateral sclerosis. Prog Neurobiol 2023; 231:102529. [PMID: 37739207 DOI: 10.1016/j.pneurobio.2023.102529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 09/11/2023] [Accepted: 09/17/2023] [Indexed: 09/24/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disease characterized by the degeneration of upper and lower motor neurons, progressive wasting and paralysis of voluntary muscles. A hallmark of ALS is the frequent nuclear loss and cytoplasmic accumulation of RNA binding proteins (RBPs) in motor neurons (MN), which leads to aberrant alternative splicing regulation. However, whether altered splicing patterns are also present in familial models of ALS without mutations in RBP-encoding genes has not been investigated yet. Herein, we found that altered splicing of synaptic genes is a common trait of familial ALS MNs. Similar deregulation was also observed in hSOD1G93A MN-like cells. In silico analysis identified the potential regulators of these pre-mRNAs, including the RBP Sam68. Immunofluorescence analysis and biochemical fractionation experiments revealed that Sam68 accumulates in the cytoplasmic insoluble ribonucleoprotein fraction of MN. Remarkably, the synaptic splicing events deregulated in ALS MNs were also affected in Sam68-/- spinal cords. Recombinant expression of Sam68 protein was sufficient to rescue these splicing changes in ALS hSOD1G93A MN-like cells. Hence, our study highlights an aberrant function of Sam68, which leads to splicing changes in synaptic genes and may contribute to the MN phenotype that characterizes ALS.
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Affiliation(s)
- Veronica Verdile
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135 Rome, Italy; Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy
| | - Ramona Palombo
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135 Rome, Italy
| | - Gabriele Ferrante
- Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy
| | - Alberto Ferri
- Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy; National Research Council (CNR), Institute of Translational Pharmacology (IFT), Rome, Italy
| | - Susanna Amadio
- Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy
| | - Cinzia Volonté
- Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy; National Research Council (CNR), Institute for Systems Analysis and Computer Science (IASI), Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Piazza Lauro de Bosis 6, 00135 Rome, Italy; Division of Experimental Neuroscience, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, Rome 00143, Italy.
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Navarro-Martínez A, Vicente-García C, Carvajal JJ. NMJ-related diseases beyond the congenital myasthenic syndromes. Front Cell Dev Biol 2023; 11:1216726. [PMID: 37601107 PMCID: PMC10436495 DOI: 10.3389/fcell.2023.1216726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/21/2023] [Indexed: 08/22/2023] Open
Abstract
Neuromuscular junctions (NMJs) are a special type of chemical synapse that transmits electrical stimuli from motor neurons (MNs) to their innervating skeletal muscle to induce a motor response. They are an ideal model for the study of synapses, given their manageable size and easy accessibility. Alterations in their morphology or function lead to neuromuscular disorders, such as the congenital myasthenic syndromes, which are caused by mutations in proteins located in the NMJ. In this review, we highlight novel potential candidate genes that may cause or modify NMJs-related pathologies in humans by exploring the phenotypes of hundreds of mouse models available in the literature. We also underscore the fact that NMJs may differ between species, muscles or even sexes. Hence the importance of choosing a good model organism for the study of NMJ-related diseases: only taking into account the specific features of the mammalian NMJ, experimental results would be efficiently translated to the clinic.
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Affiliation(s)
| | - Cristina Vicente-García
- Centro Andaluz de Biología del Desarrollo, CSIC-UPO-JA, Universidad Pablo de Olavide, Sevilla, Spain
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Varesi A, Campagnoli LIM, Barbieri A, Rossi L, Ricevuti G, Esposito C, Chirumbolo S, Marchesi N, Pascale A. RNA binding proteins in senescence: A potential common linker for age-related diseases? Ageing Res Rev 2023; 88:101958. [PMID: 37211318 DOI: 10.1016/j.arr.2023.101958] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 05/09/2023] [Accepted: 05/18/2023] [Indexed: 05/23/2023]
Abstract
Aging represents the major risk factor for the onset and/or progression of various disorders including neurodegenerative diseases, metabolic disorders, and bone-related defects. As the average age of the population is predicted to exponentially increase in the coming years, understanding the molecular mechanisms underlying the development of aging-related diseases and the discovery of new therapeutic approaches remain pivotal. Well-reported hallmarks of aging are cellular senescence, genome instability, autophagy impairment, mitochondria dysfunction, dysbiosis, telomere attrition, metabolic dysregulation, epigenetic alterations, low-grade chronic inflammation, stem cell exhaustion, altered cell-to-cell communication and impaired proteostasis. With few exceptions, however, many of the molecular players implicated within these processes as well as their role in disease development remain largely unknown. RNA binding proteins (RBPs) are known to regulate gene expression by dictating at post-transcriptional level the fate of nascent transcripts. Their activity ranges from directing primary mRNA maturation and trafficking to modulation of transcript stability and/or translation. Accumulating evidence has shown that RBPs are emerging as key regulators of aging and aging-related diseases, with the potential to become new diagnostic and therapeutic tools to prevent or delay aging processes. In this review, we summarize the role of RBPs in promoting cellular senescence and we highlight their dysregulation in the pathogenesis and progression of the main aging-related diseases, with the aim of encouraging further investigations that will help to better disclose this novel and captivating molecular scenario.
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Affiliation(s)
- Angelica Varesi
- Department of Biology and Biotechnology, University of Pavia, Pavia, Italy.
| | | | - Annalisa Barbieri
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Lorenzo Rossi
- Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | | | - Ciro Esposito
- Department of Internal Medicine and Therapeutics, University of Pavia, Italy; Nephrology and dialysis unit, ICS S. Maugeri SPA SB Hospital, Pavia, Italy; High School in Geriatrics, University of Pavia, Italy
| | | | - Nicoletta Marchesi
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy
| | - Alessia Pascale
- Department of Drug Sciences, Section of Pharmacology, University of Pavia, Pavia, Italy.
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Komiyama T, Kuroshima T, Sugasawa T, Fujita SI, Ikami Y, Hirai H, Tsushima F, Michi Y, Kayamori K, Higashino F, Harada H. High expression of Sam68 contributes to metastasis by regulating vimentin expression and a motile phenotype in oral squamous cell carcinoma. Oncol Rep 2022; 48:183. [PMID: 36082807 PMCID: PMC9478953 DOI: 10.3892/or.2022.8398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/25/2022] [Indexed: 12/24/2022] Open
Abstract
The present study aimed to investigate the clinical and biological significance of Src-associated in mitosis 68 kDa (Sam68) in oral squamous cell carcinoma (OSCC). Immunohistochemical analysis was performed on tissue samples obtained from 77 patients with OSCC. Univariate analysis revealed that the high expression of Sam68 was significantly correlated with advanced pathological T stage (P=0.01), positive lymphovascular invasion (P=0.01), and pathological cervical lymph node metastasis (P<0.01). Moreover, multivariate analysis demonstrated that the high expression of Sam68 was an independent predictive factor for cervical lymph node metastasis (odds ratio, 4.39; 95% confidence interval, 1.49-14.23; P<0.01). These results indicated that high Sam68 expression contributed to tumor progression, especially cervical lymph node metastasis, in OSCC. mRNA sequencing was also performed to assess the changes in the transcriptome between OSCC cells with Sam68 knockdown and control cells with the aim of elucidating the biological roles of Sam68. Gene Ontology enrichment analysis revealed that downregulated differentially expressed genes (DEGs) were concentrated in some biological processes related to epithelial-mesenchymal transition. Among these DEGs, it was established that vimentin was particularly downregulated in these cells. It was also confirmed that Sam68 knockdown reduced the motility of OSCC cells. Furthermore, the immunohistochemical study of vimentin identified the association between vimentin expression and Sam68 expression as well as cervical lymph node metastasis. In conclusion, the present study suggested that the high expression of Sam68 may contribute to metastasis by regulating vimentin expression and a motile mesenchymal phenotype in OSCC.
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Affiliation(s)
- Takuya Komiyama
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Takeshi Kuroshima
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Takehito Sugasawa
- Laboratory of Clinical Examination/Sports Medicine, Department of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305‑8577, Japan
| | - Shin-Ichiro Fujita
- Laboratory of Clinical Examination/Sports Medicine, Department of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki 305‑8577, Japan
| | - Yuta Ikami
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Hideaki Hirai
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Fumihiko Tsushima
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Yasuyuki Michi
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Kou Kayamori
- Department of Oral Pathology, Division of Oral Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
| | - Fumihiro Higashino
- Department of Molecular Oncology, Faculty of Dental Medicine and Graduate School of Biomedical Science and Engineering, Hokkaido University, Sapporo, Hokkaido 060‑8586, Japan
| | - Hiroyuki Harada
- Department of Oral and Maxillofacial Surgical Oncology, Division of Health Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyo‑ku, Tokyo 113‑8549, Japan
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Qiao A, Ma W, Jiang Y, Han C, Yan B, Zhou J, Qin G. Hepatic Sam68 Regulates Systemic Glucose Homeostasis and Insulin Sensitivity. Int J Mol Sci 2022; 23:ijms231911469. [PMID: 36232770 PMCID: PMC9569775 DOI: 10.3390/ijms231911469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/19/2022] [Accepted: 09/21/2022] [Indexed: 11/21/2022] Open
Abstract
Hepatic glucose production (HGP) is an important component of glucose homeostasis, and deregulated HGP, particularly through gluconeogenesis, contributes to hyperglycemia and pathology of type-2 diabetes (T2D). It has been shown that the gluconeogenic gene expression is governed primarily by the transcription factor cAMP-response element (CRE)-binding protein (CREB) and its coactivator, CREB-regulated transcriptional coactivator 2 (CRTC2). Recently, we have discovered that Sam68, an adaptor protein and Src kinase substrate, potently promotes hepatic gluconeogenesis by promoting CRTC2 stability; however, the detailed mechanisms remain unclear. Here we show that in response to glucagon, Sam68 increases CREB/CRTC2 transactivity by interacting with CRTC2 in the CREB/CRTC2 complex and occupying the CRE motif of promoters, leading to gluconeogenic gene expression and glucose production. In hepatocytes, glucagon promotes Sam68 nuclear import, whereas insulin elicits its nuclear export. Furthermore, ablation of Sam68 in hepatocytes protects mice from high-fat diet (HFD)-induced hyperglycemia and significantly increased hepatic and peripheral insulin sensitivities. Thus, hepatic Sam68 potentiates CREB/CRTC2-mediated glucose production, contributes to the pathogenesis of insulin resistance, and may serve as a therapeutic target for T2D.
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Affiliation(s)
- Aijun Qiao
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Zhongshan Institute for Drug Discovery, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Zhongshan 528400, China
- Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
- Correspondence: (A.Q.); (G.Q.); Tel.: +205-934-6690 (G.Q.); Fax: +205-934-9101 (G.Q.)
| | - Wenxia Ma
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Ying Jiang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chaoshan Han
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Baolong Yan
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Junlan Zhou
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Gangjian Qin
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
- Correspondence: (A.Q.); (G.Q.); Tel.: +205-934-6690 (G.Q.); Fax: +205-934-9101 (G.Q.)
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10
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Vilariño-García T, Guadix P, Dorado-Silva M, Sánchez-Martín P, Pérez-Pérez A, Sánchez-Margalet V. Decreased Expression of Sam68 Is Associated with Insulin Resistance in Granulosa Cells from PCOS Patients. Cells 2022; 11:cells11182821. [PMID: 36139396 PMCID: PMC9496917 DOI: 10.3390/cells11182821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/01/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, obesity, and insulin resistance, which leads to subfertility. PCOS is the most frequent metabolic disorder in women and the major cause of infertility. Susceptibility to developing PCOS is determined by a complex interaction between environmental and genetic factors. Although different mechanisms have been proposed to explain PCOS manifestations, defects in insulin actions or in the insulin signaling pathways are central in the pathogenesis of the syndrome. However, the mechanisms (molecular players and signaling pathways) underlying its primary origin still remain an unsolved issue. Current research is increasingly focusing on the discovery of novel biomarkers to further elucidate the complex pathophysiology of PCOS. Sam68, an RNA-binding protein, is recruited to insulin signaling, mediating different insulin actions. We aimed to investigate the role of Sam68 in insulin signaling and the possible implications of Sam68 in the insulin resistance in PCOS. MATERIALS AND METHODS Granulosa cells were taken from women with PCOS (n = 25) and healthy donors (n = 25) and, within the age range of 20 to 42 years, from GINEMED, Assisted Reproduction Centre, Seville, Spain. The Sam68 expression level was analyzed both by qPCR and immunoblot. Statistical significance was assessed by one-way ANOVA, followed by a post-hoc test. A p value of < 0.05 was considered statistically significant. RESULTS We found that insulin stimulation increases the phosphorylation and expression level of Sam68 in granulosa cells from normal donors. The downregulation of Sam68 expression resulted in a lower activation of both the MAPK and the PI3K pathways in response to insulin. Moreover, the granulosa cells from the women with PCOS presented a lower expression of Sam68, as well as insulin receptor and insulin receptor substrate-1 (IRS-1). In these cells, the overexpression of Sam68 resulted in an increased activation of both the MAPK and the PI3K pathways in response to insulin. CONCLUSIONS These results suggest the participation of Sam68 in insulin receptor signaling, mediating the insulin effect in granulosa cells, and they suggest the possible role of Sam68 in the insulin resistance of PCOS.
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Affiliation(s)
- Teresa Vilariño-García
- Department of Medical Biochemistry and Molecular Biology and Immunology, Virgen Macarena University Hospital, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Pilar Guadix
- Obstetrics and Gynecology Department, Virgen Macarena University Hospital, School of Medicine, University of Seville, 41009 Seville, Spain
| | | | | | - Antonio Pérez-Pérez
- Department of Medical Biochemistry and Molecular Biology and Immunology, Virgen Macarena University Hospital, School of Medicine, University of Seville, 41009 Seville, Spain
- Correspondence: (A.P.-P.); (V.S.-M.); Tel.: +95-4559-850 (A.P.-P.)
| | - Víctor Sánchez-Margalet
- Department of Medical Biochemistry and Molecular Biology and Immunology, Virgen Macarena University Hospital, School of Medicine, University of Seville, 41009 Seville, Spain
- Correspondence: (A.P.-P.); (V.S.-M.); Tel.: +95-4559-850 (A.P.-P.)
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11
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RNA-Binding Proteins in the Regulation of Adipogenesis and Adipose Function. Cells 2022; 11:cells11152357. [PMID: 35954201 PMCID: PMC9367552 DOI: 10.3390/cells11152357] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 01/27/2023] Open
Abstract
The obesity epidemic represents a critical public health issue worldwide, as it is a vital risk factor for many diseases, including type 2 diabetes (T2D) and cardiovascular disease. Obesity is a complex disease involving excessive fat accumulation. Proper adipose tissue accumulation and function are highly transcriptional and regulated by many genes. Recent studies have discovered that post-transcriptional regulation, mainly mediated by RNA-binding proteins (RBPs), also plays a crucial role. In the lifetime of RNA, it is bound by various RBPs that determine every step of RNA metabolism, from RNA processing to alternative splicing, nucleus export, rate of translation, and finally decay. In humans, it is predicted that RBPs account for more than 10% of proteins based on the presence of RNA-binding domains. However, only very few RBPs have been studied in adipose tissue. The primary aim of this paper is to provide an overview of RBPs in adipogenesis and adipose function. Specifically, the following best-characterized RBPs will be discussed, including HuR, PSPC1, Sam68, RBM4, Ybx1, Ybx2, IGF2BP2, and KSRP. Characterization of these proteins will increase our understanding of the regulatory mechanisms of RBPs in adipogenesis and provide clues for the etiology and pathology of adipose-tissue-related diseases.
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12
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Zhang W, Liu L, Zhao S, Chen L, Wei Y, Chen W, Ge F. Research progress on RNA‑binding proteins in breast cancer (Review). Oncol Lett 2022; 23:121. [PMID: 35261635 PMCID: PMC8867207 DOI: 10.3892/ol.2022.13241] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 02/03/2022] [Indexed: 11/28/2022] Open
Abstract
Breast cancer is the most common malignancy among women, and the abnormal regulation of gene expression serves an important role in its occurrence and development. However, the molecular mechanisms underlying gene expression are highly complex and heterogeneous, and RNA-binding proteins (RBPs) are among the key regulatory factors. RBPs bind targets in an environment-dependent or environment-independent manner to influence mRNA stability and the translation of genes involved in the formation, progression, metastasis and treatment of breast cancer. Due to the growing interest in these regulators, the present review summarizes the most influential studies concerning RBPs associated with breast cancer to elucidate the role of RBPs in breast cancer and to assess how they interact with other key pathways to provide new molecular targets for the diagnosis and treatment of breast cancer.
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Affiliation(s)
- Wenzhu Zhang
- Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Linlin Liu
- School of Forensic Medicine, Kunming Medical University, Kunming, Yunnan 650500, P.R. China
| | - Shengdi Zhao
- Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Liang Chen
- Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China
| | - Yuxian Wei
- Department of Endocrine Breast Surgery, First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Wenlin Chen
- Third Department of Breast Surgery, The Third Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650118, P.R. China
| | - Fei Ge
- Department of Breast Surgery, First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650032, P.R. China
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13
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Goodman WA, Basavarajappa SC, Liu AR, Rodriguez FDS, Mathes T, Ramakrishnan P. Sam68 contributes to intestinal inflammation in experimental and human colitis. Cell Mol Life Sci 2021; 78:7635-7648. [PMID: 34693458 PMCID: PMC8817240 DOI: 10.1007/s00018-021-03976-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 09/29/2021] [Accepted: 10/09/2021] [Indexed: 12/25/2022]
Abstract
Sam68 is an RNA-binding protein with an adaptor role in signal transduction. Our previous work identified critical proinflammatory and apoptotic functions for Sam68, downstream of the TNF/TNFR1 and TLR2/3/4 pathways. Recent studies have shown elevated Sam68 in inflamed tissues from rheumatoid arthritis and ulcerative colitis (UC) patients, suggesting that Sam68 contributes to chronic inflammatory diseases. Here, we hypothesized that deletion of Sam68 is protective against experimental colitis in vivo, via reductions in TNF-associated inflammatory signaling. We used Sam68 knockout (KO) mice to study the role of Sam68 in experimental colitis, including its contributions to TNF-induced inflammatory gene expression in three-dimensional intestinal organoid cultures. We also studied the expression of Sam68 and inflammatory genes in colon tissues of UC patients. Sam68 KO mice treated with an acute course of DSS exhibited significantly less weight loss and histopathological inflammation compared to wild-type controls, suggesting that Sam68 contributes to experimental colitis. Bone marrow transplants showed no pathologic role for hematopoietic cell-specific Sam68, suggesting that non-hematopoietic Sam68 drives intestinal inflammation. Gene expression analyses showed that Sam68 deficiency reduced the expression of proinflammatory genes in colon tissues from DSS-treated mice, as well as TNF-treated three-dimensional colonic organoids. We also found that inflammatory genes, such as TNF, CCR2, CSF2, IL33 and CXCL10, as well as Sam68 protein, were upregulated in inflamed colon tissues of UC patients. This report identifies Sam68 as an important inflammatory driver in response to intestinal epithelial damage, suggesting that targeting Sam68 may hold promise to treat UC patients.
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Affiliation(s)
- Wendy A Goodman
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA
| | - Shrikanth C Basavarajappa
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA
| | - Angela R Liu
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA
| | - Franklin D Staback Rodriguez
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA
| | - Tailor Mathes
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA
| | - Parameswaran Ramakrishnan
- Department of Pathology, School of Medicine, Case Western Reserve University and University Hospitals Cleveland Medical Center, 2103 Cornell Road, Room 6526, Wolstein Research Building, Cleveland, OH, 44106, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
- The Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA.
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14
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Qiao A, Ma W, Deng J, Zhou J, Han C, Zhang E, Boriboun C, Xu S, Zhang C, Jie C, Kim JA, Habegger KM, Qiu H, Zhao TC, Zhang J, Qin G. Ablation of Sam68 in adult mice increases thermogenesis and energy expenditure. FASEB J 2021; 35:e21772. [PMID: 34252225 DOI: 10.1096/fj.202100021r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/27/2021] [Accepted: 06/17/2021] [Indexed: 12/18/2022]
Abstract
Genetic deletion of Src associated in mitosis of 68kDa (Sam68), a pleiotropic adaptor protein prevents high-fat diet-induced weight gain and insulin resistance. To clarify the role of Sam68 in energy metabolism in the adult stage, we generated an inducible Sam68 knockout mice. Knockout of Sam68 was induced at the age of 7-10 weeks, and then we examined the metabolic profiles of the mice. Sam68 knockout mice gained less body weight over time and at 34 or 36 weeks old, had smaller fat mass without changes in food intake and absorption efficiency. Deletion of Sam68 in mice elevated thermogenesis, increased energy expenditure, and attenuated core-temperature drop during acute cold exposure. Furthermore, we examined younger Sam68 knockout mice at 11 weeks old before their body weights deviate, and confirmed increased energy expenditure and thermogenic gene program. Thus, Sam68 is essential for the control of adipose thermogenesis and energy homeostasis in the adult.
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Affiliation(s)
- Aijun Qiao
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Wenxia Ma
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jianxin Deng
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Junlan Zhou
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Chaoshan Han
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Eric Zhang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Chan Boriboun
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Shiyue Xu
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Chunxiang Zhang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Chunfa Jie
- Department of Biochemistry and Nutrition, Des Moines University College of Osteopathic Medicine, Des Moines, IA, USA
| | - Jeong-A Kim
- Department of Medicine-Endocrinology, Diabetes & Metabolism, Comprehensive Diabetes Center, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kirk M Habegger
- Department of Medicine-Endocrinology, Diabetes & Metabolism, Comprehensive Diabetes Center, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hongyu Qiu
- Center for Molecular and Translational Medicine, Institute of Biomedical Science, Georgia State University, Atlanta, GA, USA
| | - Ting C Zhao
- Department of Surgery, Boston University Medical School, Roger Williams Medical Center, Providence, RI, USA
| | - Jianyi Zhang
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Gangjian Qin
- Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL, USA.,Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
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15
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Qiao A, Zhou J, Xu S, Ma W, Boriboun C, Kim T, Yan B, Deng J, Yang L, Zhang E, Song Y, Ma YC, Richard S, Zhang C, Qiu H, Habegger KM, Zhang J, Qin G. Sam68 promotes hepatic gluconeogenesis via CRTC2. Nat Commun 2021; 12:3340. [PMID: 34099657 PMCID: PMC8185084 DOI: 10.1038/s41467-021-23624-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Accepted: 05/05/2021] [Indexed: 02/07/2023] Open
Abstract
Hepatic gluconeogenesis is essential for glucose homeostasis and also a therapeutic target for type 2 diabetes, but its mechanism is incompletely understood. Here, we report that Sam68, an RNA-binding adaptor protein and Src kinase substrate, is a novel regulator of hepatic gluconeogenesis. Both global and hepatic deletions of Sam68 significantly reduce blood glucose levels and the glucagon-induced expression of gluconeogenic genes. Protein, but not mRNA, levels of CRTC2, a crucial transcriptional regulator of gluconeogenesis, are >50% lower in Sam68-deficient hepatocytes than in wild-type hepatocytes. Sam68 interacts with CRTC2 and reduces CRTC2 ubiquitination. However, truncated mutants of Sam68 that lack the C- (Sam68ΔC) or N-terminal (Sam68ΔN) domains fails to bind CRTC2 or to stabilize CRTC2 protein, respectively, and transgenic Sam68ΔN mice recapitulate the blood-glucose and gluconeogenesis profile of Sam68-deficient mice. Hepatic Sam68 expression is also upregulated in patients with diabetes and in two diabetic mouse models, while hepatocyte-specific Sam68 deficiencies alleviate diabetic hyperglycemia and improves insulin sensitivity in mice. Thus, our results identify a role for Sam68 in hepatic gluconeogenesis, and Sam68 may represent a therapeutic target for diabetes. Hepatic gluconeogenesis is important for glucose homeostasis and a therapeutic target for type 2 diabetes. Here, the authors show that the RNA-binding adaptor protein Sam68 promotes the expression level of gluconeogenic genes and increases blood glucose levels by stabilizing the transcriptional coactivator CRTC2, while hepatic Sam68 deletion alleviates hyperglycemia in mice.
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Affiliation(s)
- Aijun Qiao
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Junlan Zhou
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Shiyue Xu
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Wenxia Ma
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Chan Boriboun
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Teayoun Kim
- Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, School of Medicine, Birmingham, AL, USA
| | - Baolong Yan
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Jianxin Deng
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Liu Yang
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Eric Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Yuhua Song
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Yongchao C Ma
- Departments of Pediatrics, Neurology and Physiology, Northwestern University Feinberg School of Medicine, Anne & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Stephane Richard
- Lady Davis Institute for Medical Research, McGill University, Montreal, QC, Canada
| | - Chunxiang Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Hongyu Qiu
- Center for Molecular and Translational Medicine, Institute of Biomedical Science Georgia State University, Atlanta, GA, USA
| | - Kirk M Habegger
- Department of Medicine - Endocrinology, Diabetes & Metabolism, University of Alabama at Birmingham, School of Medicine, Birmingham, AL, USA
| | - Jianyi Zhang
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA
| | - Gangjian Qin
- Department of Biomedical Engineering, University of Alabama at Birmingham, School of Medicine and School of Engineering, Birmingham, AL, USA. .,Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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16
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Farini D, Cesari E, Weatheritt RJ, La Sala G, Naro C, Pagliarini V, Bonvissuto D, Medici V, Guerra M, Di Pietro C, Rizzo FR, Musella A, Carola V, Centonze D, Blencowe BJ, Marazziti D, Sette C. A Dynamic Splicing Program Ensures Proper Synaptic Connections in the Developing Cerebellum. Cell Rep 2021; 31:107703. [PMID: 32492419 DOI: 10.1016/j.celrep.2020.107703] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 03/13/2020] [Accepted: 05/07/2020] [Indexed: 12/14/2022] Open
Abstract
Tight coordination of gene expression in the developing cerebellum is crucial for establishment of neuronal circuits governing motor and cognitive function. However, transcriptional changes alone do not explain all of the switches underlying neuronal differentiation. Here we unveiled a widespread and highly dynamic splicing program that affects synaptic genes in cerebellar neurons. The motifs enriched in modulated exons implicated the splicing factor Sam68 as a regulator of this program. Sam68 controls splicing of exons with weak branchpoints by directly binding near the 3' splice site and competing with U2AF recruitment. Ablation of Sam68 disrupts splicing regulation of synaptic genes associated with neurodevelopmental diseases and impairs synaptic connections and firing of Purkinje cells, resulting in motor coordination defects, ataxia, and abnormal social behavior. These findings uncover an unexpectedly dynamic splicing regulatory network that shapes the synapse in early life and establishes motor and cognitive circuitry in the developing cerebellum.
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Affiliation(s)
- Donatella Farini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy; Fondazione Santa Lucia, IRCCS, Rome, Italy
| | - Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Robert J Weatheritt
- Donnelly Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada; EMBL Australia, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
| | - Gina La Sala
- Institute of Cell Biology and Neurobiology, CNR, Monterotondo, Rome, Italy
| | - Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Davide Bonvissuto
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
| | - Vanessa Medici
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy; Fondazione Santa Lucia, IRCCS, Rome, Italy
| | - Marika Guerra
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy; Fondazione Policlinico Universitario A. Gemelli, IRCCS, Rome, Italy
| | - Chiara Di Pietro
- Institute of Cell Biology and Neurobiology, CNR, Monterotondo, Rome, Italy
| | - Francesca Romana Rizzo
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy; San Raffaele Pisana and University San Raffaele, IRCCS, Rome, Italy
| | | | - Valeria Carola
- Fondazione Santa Lucia, IRCCS, Rome, Italy; Department of Dynamic and Clinical Psychology, University of Rome Sapienza, Rome, Italy
| | - Diego Centonze
- Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy; Unit of Neurology, IRCCS Neuromed, Pozzilli, Isernia, Italy
| | - Benjamin J Blencowe
- Donnelly Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Daniela Marazziti
- Institute of Cell Biology and Neurobiology, CNR, Monterotondo, Rome, Italy
| | - Claudio Sette
- Fondazione Santa Lucia, IRCCS, Rome, Italy; Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy.
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17
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Naro C, Cesari E, Sette C. Splicing regulation in brain and testis: common themes for highly specialized organs. Cell Cycle 2021; 20:480-489. [PMID: 33632061 PMCID: PMC8018374 DOI: 10.1080/15384101.2021.1889187] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 01/17/2021] [Accepted: 02/07/2021] [Indexed: 12/26/2022] Open
Abstract
Expansion of the coding and regulatory capabilities of eukaryotic transcriptomes by alternative splicing represents one of the evolutionary forces underlying the increased structural complexity of metazoans. Brain and testes stand out as the organs that mostly exploit the potential of alternative splicing, thereby expressing the largest repertoire of splice variants. Herein, we will review organ-specific as well as common mechanisms underlying the high transcriptome complexity of these organs and discuss the impact exerted by this widespread alternative splicing regulation on the functionality and differentiation of brain and testicular cells.
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Affiliation(s)
- Chiara Naro
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Eleonora Cesari
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, Rome, Italy
- Laboratory of Neuroembryology, IRCCS Fondazione Santa Lucia, Rome, Italy
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18
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Duque G, Al Saedi A, Rivas D, Miard S, Ferland G, Picard F, Gaudreau P. Differential Effects of Long-Term Caloric Restriction and Dietary Protein Source on Bone and Marrow Fat of the Aging Rat. J Gerontol A Biol Sci Med Sci 2021; 75:2031-2036. [PMID: 32298404 DOI: 10.1093/gerona/glaa093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Indexed: 01/11/2023] Open
Abstract
Long-term caloric restriction (CR) has been shown to be beneficial to various tissues and organs. In contrast, CR exerts differential effects on bone, which could be due in part to the nature of the protein regime utilized. Male Sprague Dawley rats (8-month-old) were subjected for 12 months to 40% CR in macronutrients and compared with rats fed ad libitum for the same period. Casein- and soy-fed groups were compared. There was a significant decrease in bone quality in both CR groups, which was independent of the source of protein in the diet. In contrast, the group fed soy protein ad libitum showed better bone quality and higher levels of bone formation compared with casein-fed animals. Notably, bone marrow adipocytes were not mobilized upon CR as demonstrated by an absence of change in adipocyte number and tissue expression of leptin. This study demonstrates that the negative effect of CR on bone quality could not be prevented by the most common protein regimes.
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Affiliation(s)
- Gustavo Duque
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, Australia.,Department of Medicine-Western Health, University of Melbourne, St. Albans, Australia
| | - Ahmed Al Saedi
- Australian Institute for Musculoskeletal Science (AIMSS), The University of Melbourne and Western Health, St. Albans, Australia.,Department of Medicine-Western Health, University of Melbourne, St. Albans, Australia
| | - Daniel Rivas
- Lady Davis Institute for Medical Research, Montreal, Canada
| | | | - Guylaine Ferland
- Département de nutrition, Faculté de médecine de l'Université de Montréal (UdeM), Canada.,Centre de recherche de l'Institut de cardiologie de Montréal, Canada
| | - Frederic Picard
- Quebec Heart and Lung Institute, Canada.,Faculty of Pharmacy, Université Laval, Québec, Canada
| | - Pierrette Gaudreau
- Département de médecine, UdeM, Montreal, Canada.,Laboratoire de Neuroendocrinologie du vieillissement, Centre de Recherche du Centre hospitalier de l'UdeM, Montréal, Canada
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19
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS. RNA 2021. [PMID: 33565261 DOI: 10.1002/wrna.1643.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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20
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Angarola BL, Anczuków O. Splicing alterations in healthy aging and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 12:e1643. [PMID: 33565261 DOI: 10.1002/wrna.1643] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 01/05/2021] [Accepted: 01/07/2021] [Indexed: 12/19/2022]
Abstract
Alternative RNA splicing is a key step in gene expression that allows generation of numerous messenger RNA transcripts encoding proteins of varied functions from the same gene. It is thus a rich source of proteomic and functional diversity. Alterations in alternative RNA splicing are observed both during healthy aging and in a number of human diseases, several of which display premature aging phenotypes or increased incidence with age. Age-associated splicing alterations include differential splicing of genes associated with hallmarks of aging, as well as changes in the levels of core spliceosomal genes and regulatory splicing factors. Here, we review the current known links between alternative RNA splicing, its regulators, healthy biological aging, and diseases associated with aging or aging-like phenotypes. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA.,Department of Genetics and Genome Sciences, UConn Health, Farmington, Connecticut, USA.,Institute for Systems Genomics, UConn Health, Farmington, Connecticut, USA
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21
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Klein ME, Younts TJ, Cobo CF, Buxbaum AR, Aow J, Erdjument-Bromage H, Richard S, Malinow R, Neubert TA, Singer RH, Castillo PE, Jordan BA. Sam68 Enables Metabotropic Glutamate Receptor-Dependent LTD in Distal Dendritic Regions of CA1 Hippocampal Neurons. Cell Rep 2020; 29:1789-1799.e6. [PMID: 31722197 PMCID: PMC6871770 DOI: 10.1016/j.celrep.2019.10.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 08/15/2019] [Accepted: 10/08/2019] [Indexed: 12/13/2022] Open
Abstract
The transport and translation of dendritic mRNAs by RNA-binding proteins (RBPs) allows for spatially restricted gene expression in neuronal processes. Although local translation in neuronal dendrites is now well documented, there is little evidence for corresponding effects on local synaptic function. Here, we report that the RBP Sam68 promotes the localization and translation of Arc mRNA preferentially in distal dendrites of rodent hippocampal CA1 pyramidal neurons. Consistent with Arc function in translation-dependent synaptic plasticity, we find that Sam68 knockout (KO) mice display impaired metabotropic glutamate-receptor-dependent long-term depression (mGluR-LTD) and impaired structural plasticity exclusively at distal Schaffer-collateral synapses. Moreover, by using quantitative proteomics, we find that the Sam68 interactome contains numerous regulators of mRNA translation and synaptic function. This work identifies an important player in Arc expression, provides a general framework for Sam68 regulation of protein synthesis, and uncovers a mechanism that enables the precise spatiotemporal expression of long-term plasticity throughout neurons.
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Affiliation(s)
- Matthew E Klein
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Thomas J Younts
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Carmen Freire Cobo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Adina R Buxbaum
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; Center for Neural Circuits and Behavior, Department of Neuroscience and Section for Neurobiology, Division of Biology, University of California at San Diego, San Diego, CA 92093, USA
| | - Jonathan Aow
- Center for Neural Circuits and Behavior, Department of Neuroscience and Section for Neurobiology, Division of Biology, University of California at San Diego, San Diego, CA 92093, USA
| | - Hediye Erdjument-Bromage
- Department of Cell Biology and Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Stéphane Richard
- Segal Cancer Center, Lady Davis Institute for Medical Research and Departments of Oncology and Medicine, McGill University, Montréal, QC H3T 1E2, Canada
| | - Roberto Malinow
- Center for Neural Circuits and Behavior, Department of Neuroscience and Section for Neurobiology, Division of Biology, University of California at San Diego, San Diego, CA 92093, USA
| | - Thomas A Neubert
- Department of Cell Biology and Kimmel Center for Biology and Medicine, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA
| | - Robert H Singer
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; Janelia Research Campus of the Howard Hughes Medical Institute, Ashburn, VA 20147, USA
| | - Pablo E Castillo
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Bryen A Jordan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA; Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA.
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22
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De Paola E, Forcina L, Pelosi L, Pisu S, La Rosa P, Cesari E, Nicoletti C, Madaro L, Mercatelli N, Biamonte F, Nobili A, D'Amelio M, De Bardi M, Volpe E, Caporossi D, Sette C, Musarò A, Paronetto MP. Sam68 splicing regulation contributes to motor unit establishment in the postnatal skeletal muscle. Life Sci Alliance 2020; 3:3/10/e201900637. [PMID: 32753528 PMCID: PMC7409371 DOI: 10.26508/lsa.201900637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 01/08/2023] Open
Abstract
Sam68 ensures the establishment of neuromuscular junctions (NMJs) and motor unit integrity by orchestrating a neuronal splicing program. RNA-binding proteins orchestrate the composite life of RNA molecules and impact most physiological processes, thus underlying complex phenotypes. The RNA-binding protein Sam68 regulates differentiation processes by modulating splicing, polyadenylation, and stability of select transcripts. Herein, we found that Sam68−/− mice display altered regulation of alternative splicing in the spinal cord of key target genes involved in synaptic functions. Analysis of the motor units revealed that Sam68 ablation impairs the establishment of neuromuscular junctions and causes progressive loss of motor neurons in the spinal cord. Importantly, alterations of neuromuscular junction morphology and properties in Sam68−/− mice correlate with defects in muscle and motor unit integrity. Sam68−/− muscles display defects in postnatal development, with manifest signs of atrophy. Furthermore, fast-twitch muscles in Sam68−/− mice show structural features typical of slow-twitch muscles, suggesting alterations in the metabolic and functional properties of myofibers. Collectively, our data identify a key role for Sam68 in muscle development and suggest that proper establishment of motor units requires timely expression of synaptic splice variants.
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Affiliation(s)
- Elisa De Paola
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy.,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Laura Forcina
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Laura Pelosi
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Simona Pisu
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Piergiorgio La Rosa
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Eleonora Cesari
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Carmine Nicoletti
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Luca Madaro
- Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Neri Mercatelli
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy.,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Filippo Biamonte
- Institute of Biochemistry and Clinical Biochemistry, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Annalisa Nobili
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Marcello D'Amelio
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy.,Department of Medicine, University Campus-Biomedico, Rome, Italy
| | - Marco De Bardi
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Elisabetta Volpe
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
| | - Daniela Caporossi
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy
| | - Claudio Sette
- IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy .,Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Heart, Rome, Italy
| | - Antonio Musarò
- Laboratory Affiliated to Istituto Pasteur-Fondazione Cenci Bolognetti, DAHFMO-Unit of Histology and Medical Embryology, Sapienza University of Rome, Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico," Rome, Italy .,IRCCS (Institute for Treatment and Research) Fondazione Santa Lucia, Rome, Italy
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23
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Vilariño-García T, Pérez-Pérez A, Santamaría-López E, Prados N, Fernández-Sánchez M, Sánchez-Margalet V. Sam68 mediates leptin signaling and action in human granulosa cells: possible role in leptin resistance in PCOS. Endocr Connect 2020; 9:479-488. [PMID: 32375121 PMCID: PMC7354740 DOI: 10.1530/ec-20-0062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 05/06/2020] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, obesity, and insulin resistance, that leads to subfertility. Sam68 is an RNA-binding protein with signaling functions that is ubiquitously expressed, including gonads. Sam68 is recruited to leptin signaling, mediating different leptin actions. OBJECTIVE We aimed to investigate the role of Sam68 in leptin signaling, mediating the effect on aromatase expression in granulosa cells and the posible implication of Sam68 in the leptin resistance in PCOS. MATERIALS AND METHODS Granulosa cells were from healthy donors (n = 25) and women with PCOS (n = 25), within the age range of 20 to 40 years, from Valencian Infertility Institute (IVI), Seville, Spain. Sam68 expression was inhibited by siRNA method and overexpressed by expression vector. Expression level was analysed by qPCR and immunoblot. Statistical significance was assessed by ANOVA followed by different post-hoc tests. A P value of <0.05 was considered statistically significant. RESULTS We have found that leptin stimulation increases phosphorylation and expression level of Sam68 and aromatase in granulosa cells from normal donors. Downregulation of Sam68 expression resulted in a lower activation of MAPK and PI3K pathways in response to leptin, whereas overexpression of Sam68 increased leptin stimulation of signaling, enhancing aromatase expression. Granulosa cells from women with PCOS presented lower expression of Sam68 and were resistant to the leptin effect on aromatase expression. CONCLUSIONS These results suggest the participation of Sam68 in leptin receptor signaling, mediating the leptin effect on aromatase expression in granulosa cells, and point to a new target in leptin resistance in PCOS.
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Affiliation(s)
- Teresa Vilariño-García
- Department of Medical Biochemistry, Molecular Biology and Immunology. Medical School, Virgen Macarena University Hospital, University of Seville, Seville, Spain
| | - Antonio Pérez-Pérez
- Department of Medical Biochemistry, Molecular Biology and Immunology. Medical School, Virgen Macarena University Hospital, University of Seville, Seville, Spain
| | | | | | | | - Víctor Sánchez-Margalet
- Department of Medical Biochemistry, Molecular Biology and Immunology. Medical School, Virgen Macarena University Hospital, University of Seville, Seville, Spain
- Correspondence should be addressed to V Sánchez-Margalet:
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24
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Naro C, Pellegrini L, Jolly A, Farini D, Cesari E, Bielli P, de la Grange P, Sette C. Functional Interaction between U1snRNP and Sam68 Insures Proper 3' End Pre-mRNA Processing during Germ Cell Differentiation. Cell Rep 2020; 26:2929-2941.e5. [PMID: 30865884 DOI: 10.1016/j.celrep.2019.02.058] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 01/15/2019] [Accepted: 02/14/2019] [Indexed: 01/02/2023] Open
Abstract
Male germ cells express the widest repertoire of transcript variants in mammalian tissues. Nevertheless, factors and mechanisms underlying such pronounced diversity are largely unknown. The splicing regulator Sam68 is highly expressed in meiotic cells, and its ablation results in defective spermatogenesis. Herein, we uncover an extensive splicing program operated by Sam68 across meiosis, primarily characterized by alternative last exon (ALE) regulation in genes of functional relevance for spermatogenesis. Lack of Sam68 preferentially causes premature transcript termination at internal polyadenylation sites, a feature observed also upon depletion of the spliceosomal U1snRNP in somatic cells. Notably, Sam68-regulated ALEs are characterized by proximity between U1snRNP and Sam68 binding motifs. We demonstrate a physical association between Sam68 and U1snRNP and show that U1snRNP recruitment to Sam68-regulated ALEs is impaired in Sam68-/- germ cells. Thus, our study reveals an unexpected cooperation between Sam68 and U1snRNP that insures proper processing of transcripts essential for male fertility.
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Affiliation(s)
- Chiara Naro
- Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Hearth, 00168 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Livia Pellegrini
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Ariane Jolly
- GenoSplice Technology, iPEPS-ICM, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Donatella Farini
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Eleonora Cesari
- Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Hearth, 00168 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Pamela Bielli
- Department of Biomedicine and Prevention, University of Rome "Tor Vergata," 00133 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Pierre de la Grange
- GenoSplice Technology, iPEPS-ICM, Hôpital de la Pitié Salpêtrière, 75013 Paris, France
| | - Claudio Sette
- Institute of Human Anatomy and Cell Biology, Catholic University of the Sacred Hearth, 00168 Rome, Italy; IRCCS Fondazione Santa Lucia, 00143 Rome, Italy.
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25
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Maroni P. Leptin, Adiponectin, and Sam68 in Bone Metastasis from Breast Cancer. Int J Mol Sci 2020; 21:ijms21031051. [PMID: 32033341 PMCID: PMC7037668 DOI: 10.3390/ijms21031051] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 12/12/2022] Open
Abstract
The most serious aspect of neoplastic disease is the spread of cancer cells to secondary sites. Skeletal metastases can escape detection long after treatment of the primary tumour and follow-up. Bone tissue is a breeding ground for many types of cancer cells, especially those derived from the breast, prostate, and lung. Despite advances in diagnosis and therapeutic strategies, bone metastases still have a profound impact on quality of life and survival and are often responsible for the fatal outcome of the disease. Bone and the bone marrow environment contain a wide variety of cells. No longer considered a passive filler, bone marrow adipocytes have emerged as critical contributors to cancer progression. Released by adipocytes, adipokines are soluble factors with hormone-like functions and are currently believed to affect tumour development. Src-associated in mitosis of 68 kDa (Sam68), originally discovered as a protein physically associated with and phosphorylated by c-Src during mitosis, is now recognised as an important RNA-binding protein linked to tumour onset and progression of disease. Sam68 also regulates splicing events and recent evidence reports that dysregulation of these events is a key step in neoplastic transformation and tumour progression. The present review reports recent findings on adipokines and Sam68 and their role in breast cancer progression and metastasis.
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Affiliation(s)
- Paola Maroni
- IRCCS Istituto Ortopedico Galeazzi, Via R. Galeazzi 4, 20161 Milano, Italy
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26
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Han S, Xu S, Zhou J, Qiao A, Boriboun C, Ma W, Li H, Biyashev D, Yang L, Zhang E, Liu Q, Jiang S, Zhao TC, Krishnamurthy P, Zhang C, Richard S, Qiu H, Zhang J, Qin G. Sam68 impedes the recovery of arterial injury by augmenting inflammatory response. J Mol Cell Cardiol 2019; 137:82-92. [PMID: 31639388 DOI: 10.1016/j.yjmcc.2019.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 09/23/2019] [Accepted: 10/14/2019] [Indexed: 12/15/2022]
Abstract
OBJECTIVE The role of Src-associated-in-mitosis-68-kDa (Sam68) in cardiovascular biology has not been studied. A recent report suggests that Sam68 promotes TNF-α-induced NF-κB activation in fibroblasts. Here we sought to dissect the molecular mechanism by which Sam68 regulates NF-κB signaling and its functional significance in vascular injury. APPROACH AND RESULTS The endothelial denudation injury was induced in the carotid artery of Sam68-null (Sam68-/-) and WT mice. Sam68-/- mice displayed an accelerated re-endothelialization and attenuated neointima hyperplasia, which was associated with a reduced macrophage infiltration and lowered expression of pro-inflammatory cytokines in the injured vessels. Remarkably, the ameliorated vascular remodeling was recapitulated in WT mice after receiving transplantation of bone marrow (BM) from Sam68-/- mice, suggesting the effect was attributable to BM-derived inflammatory cells. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, IL-1β, and IL-6 and in the level of nuclear phospho-p65, indicating attenuated NF-κB activation; and these results were confirmed in peritoneal and BM-derived macrophages of Sam68-/- vs. WT mice. Furthermore, co-immunoprecipitation and mass-spectrometry identified Filamin A (FLNA) as a novel Sam68-interacting protein upon TNF-α treatment. Loss- and gain-of-function experiments suggest that Sam68 and FLNA are mutually dependent for NF-κB activation and pro-inflammatory cytokine expression, and that the N-terminus of Sam68 is required for TRAF2-FLNA interaction. CONCLUSIONS Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery by interacting with FLNA to stabilize TRAF2 on the cytoskeleton and consequently potentiate NF-κB signaling.
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Affiliation(s)
- Shuling Han
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Shiyue Xu
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Junlan Zhou
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Aijun Qiao
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chan Boriboun
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Wenxia Ma
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Huadong Li
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Dauren Biyashev
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Liu Yang
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Eric Zhang
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Qinghua Liu
- Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China, College of Life Sciences, South-Central University for Nationalities, Wuhan 430074, Hubei, China
| | - Shayi Jiang
- Department of Hematology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai 20062, China
| | - Ting C Zhao
- Department of Surgery, Roger Williams Medical Center, Boston University Medical School, Providence, RI 02908, USA
| | - Prasanna Krishnamurthy
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Chunxiang Zhang
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Stéphane Richard
- Lady Davis Institute for Medical Research, McGill University, Montreal, Quebec, Canada
| | - Hongyu Qiu
- Center of Molecular and Translational Medicine, Institution of Biomedical Science, Georgia State University, Atlanta, GA 30303, USA
| | - Jianyi Zhang
- Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Gangjian Qin
- Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Molecular Cardiology Program, Department of Biomedical Engineering, School of Medicine and School of Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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27
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Fu K, Sun X, Xia X, Hobbs RP, Guo Y, Coulombe PA, Wan F. Sam68 is required for the growth and survival of nonmelanoma skin cancer. Cancer Med 2019; 8:6106-6113. [PMID: 31436046 PMCID: PMC6792479 DOI: 10.1002/cam4.2513] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/07/2019] [Accepted: 08/11/2019] [Indexed: 12/20/2022] Open
Abstract
Although targeting DNA repair signaling pathways has emerged as a promising therapeutic for skin cancer, the relevance of DNA damage responses (DDR) in the development and survival of nonmelanoma skin cancer (NMSC), the most common type of skin cancer, remains obscure. Here, we report that Src-associated substrate during mitosis of 68 kDa (Sam68), an early signaling molecule in DDR, is elevated in skin tumor tissues derived from NMSC patients and skin lesions from Gli2-transgenic mice. Downregulation of Sam68 impacts the growth and survival of human tumor keratinocytes and genetic ablation of Sam68 delays the onset of basal cell carcinomas (BCC) in Gli2-transgenic mice. Moreover, Sam68 plays a critical role in DNA damage-induced DNA repair and nuclear factor kappa B (NF-κB) signaling pathways in keratinocytes, hence conferring keratinocyte sensitivity to DNA damaging agents. Together, our data reveal a novel function of Sam68 in regulating DDR in keratinocytes that is crucial for the growth and survival of NMSC.
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Affiliation(s)
- Kai Fu
- Institute of Molecular Precision Medicine and Hunan Key Laboratory of Molecular Precision Medicine, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Oncology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Xin Sun
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,The Rockefeller University, New York, NY, USA
| | - Xue Xia
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Ryan P Hobbs
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Dermatology, College of Medicine, Pennsylvania State University, Hershey, PA, USA
| | - Yajuan Guo
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Pierre A Coulombe
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Dermatology, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - Fengyi Wan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Oncology, Johns Hopkins University School of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, MD, USA.,W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
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28
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Witte H, Schreiner D, Scheiffele P. A Sam68-dependent alternative splicing program shapes postsynaptic protein complexes. Eur J Neurosci 2019; 49:1436-1453. [PMID: 30589479 DOI: 10.1111/ejn.14332] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/13/2018] [Accepted: 12/19/2018] [Indexed: 12/30/2022]
Abstract
Alternative splicing is one of the key mechanisms to increase the diversity of cellular transcriptomes, thereby expanding the coding capacity of the genome. This diversity is of particular importance in the nervous system with its elaborated cellular networks. Sam68, a member of the Signal Transduction Associated RNA-binding (STAR) family of RNA-binding proteins, is expressed in the developing and mature nervous system but its neuronal functions are poorly understood. Here, we perform genome-wide mapping of the Sam68-dependent alternative splicing program in mice. We find that Sam68 is required for the regulation of a set of alternative splicing events in pre-mRNAs encoding several postsynaptic scaffolding molecules that are central to the function of GABAergic and glutamatergic synapses. These components include Collybistin (Arhgef9), Gephyrin (Gphn), and Densin-180 (Lrrc7). Sam68-regulated Lrrc7 variants engage in differential protein interactions with signalling proteins, thus, highlighting a contribution of the Sam68 splicing program to shaping synaptic complexes. These findings suggest an important role for Sam68-dependent alternative splicing in the regulation of synapses in the central nervous system.
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Affiliation(s)
- Harald Witte
- Biozentrum of the University of Basel, Basel, Switzerland
| | - Dietmar Schreiner
- Biozentrum of the University of Basel, Basel, Switzerland.,Institute of Neuroanatomy and Cell Biology, Hannover, Germany
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29
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The RNA binding protein Sam68 controls T helper 1 differentiation and anti-mycobacterial response through modulation of miR-29. Cell Death Differ 2018; 26:1169-1180. [PMID: 30258098 DOI: 10.1038/s41418-018-0201-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 08/08/2018] [Accepted: 08/27/2018] [Indexed: 12/24/2022] Open
Abstract
Polarization of naive T cells into interferon (IFN)-γ-producing T helper 1 (Th1) cells is an essential event in the inflammatory response to pathogens. Herein, we identify the RNA binding protein Sam68 as a specific modulator of Th1 differentiation. Sam68-knockout (ko) naive T cells are strongly defective in IL-12-mediated Th1 polarization and express low levels of T-bet and Eomes. Consequently, Sam68-ko Th1 cells are significantly impaired in IFN-γ production. Moreover, we found that Sam68 is required for the induction of an inflammatory Th1 response during Mycobacterium bovis Bacillus Calmette-Guerin (BCG) infection, thus limiting bacterial dissemination in the lungs. Mechanistically, Sam68 directly binds to the microRNA miR-29, a negative regulator of Th1 response, and inhibits its expression during BCG infection. These findings uncover a novel post-transcriptional mechanism required for the Th1-mediated defense against intracellular pathogens and identify a new function for Sam68 in the regulation of the immune response.
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Li N, Ngo CTA, Aleynikova O, Beauchemin N, Richard S. The p53 status can influence the role of Sam68 in tumorigenesis. Oncotarget 2018; 7:71651-71659. [PMID: 27690217 PMCID: PMC5342108 DOI: 10.18632/oncotarget.12305] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 09/20/2016] [Indexed: 02/02/2023] Open
Abstract
The expression and activities of RNA binding proteins are frequently dysregulated in human cancer. Their roles, however, appears to be complex, with reports indicating both pro-tumorigenic and tumor suppressive functions. Here we show, using two classical mouse cancer models, that the role of KH-type RNA binding protein, Sam68, in tumor development can be influenced by the status of the p53 tumor suppressor. We demonstrate that in mice expressing wild type p53, Sam68-deficiency resulted in a higher incidence and malignancy of carcinogen-induced tumors, suggesting a tumor suppressive role for Sam68. In marked contrast, Sam68-haploinsufficiency significantly delayed the onset of tumors in mice lacking p53 and prolonged their survival, indicating that Sam68 accelerates the development of p53-deficient tumors. These findings provide considerable insight into a previously unknown relationship between Sam68 and the p53 tumor suppressor in tumorigenesis.
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Affiliation(s)
- Naomi Li
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
| | - Chau Tuan-Anh Ngo
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
| | - Olga Aleynikova
- Department of Pathology, Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
| | - Nicole Beauchemin
- Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada.,Department of Biochemistry, McGill University, Montréal, Québec H3G 1Y6, Canada.,Rosalind and Morris Goodman Cancer Centre, Montréal, Québec H3A 1A3, Canada
| | - Stéphane Richard
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
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Deschênes M, Chabot B. The emerging role of alternative splicing in senescence and aging. Aging Cell 2017; 16:918-933. [PMID: 28703423 PMCID: PMC5595669 DOI: 10.1111/acel.12646] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2017] [Indexed: 12/22/2022] Open
Abstract
Deregulation of precursor mRNA splicing is associated with many illnesses and has been linked to age-related chronic diseases. Here we review recent progress documenting how defects in the machinery that performs intron removal and controls splice site selection contribute to cellular senescence and organismal aging. We discuss the functional association linking p53, IGF-1, SIRT1, and ING-1 splice variants with senescence and aging, and review a selection of splicing defects occurring in accelerated aging (progeria), vascular aging, and Alzheimer's disease. Overall, it is becoming increasingly clear that changes in the activity of splicing factors and in the production of key splice variants can impact cellular senescence and the aging phenotype.
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Affiliation(s)
- Mathieu Deschênes
- Department of Microbiology and Infectious DiseasesFaculty of Medicine and Health SciencesUniversité de SherbrookeSherbrookeQuebecJ1E 4K8Canada
| | - Benoit Chabot
- Department of Microbiology and Infectious DiseasesFaculty of Medicine and Health SciencesUniversité de SherbrookeSherbrookeQuebecJ1E 4K8Canada
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Danilenko M, Dalgliesh C, Pagliarini V, Naro C, Ehrmann I, Feracci M, Kheirollahi-Chadegani M, Tyson-Capper A, Clowry GJ, Fort P, Dominguez C, Sette C, Elliott DJ. Binding site density enables paralog-specific activity of SLM2 and Sam68 proteins in Neurexin2 AS4 splicing control. Nucleic Acids Res 2017; 45:4120-4130. [PMID: 27994030 PMCID: PMC5397175 DOI: 10.1093/nar/gkw1277] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 12/08/2016] [Indexed: 01/09/2023] Open
Abstract
SLM2 and Sam68 are splicing regulator paralogs that usually overlap in function, yet only SLM2 and not Sam68 controls the Neurexin2 AS4 exon important for brain function. Herein we find that SLM2 and Sam68 similarly bind to Neurexin2 pre-mRNA, both within the mouse cortex and in vitro. Protein domain-swap experiments identify a region including the STAR domain that differentiates SLM2 and Sam68 activity in splicing target selection, and confirm that this is not established via the variant amino acids involved in RNA contact. However, far fewer SLM2 and Sam68 RNA binding sites flank the Neurexin2 AS4 exon, compared with those flanking the Neurexin1 and Neurexin3 AS4 exons under joint control by both Sam68 and SLM2. Doubling binding site numbers switched paralog sensitivity, by placing the Neurexin2 AS4 exon under joint splicing control by both Sam68 and SLM2. Our data support a model where the density of shared RNA binding sites around a target exon, rather than different paralog-specific protein-RNA binding sites, controls functional target specificity between SLM2 and Sam68 on the Neurexin2 AS4 exon. Similar models might explain differential control by other splicing regulators within families of paralogs with indistinguishable RNA binding sites.
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Affiliation(s)
- Marina Danilenko
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Caroline Dalgliesh
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Vittoria Pagliarini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
| | - Chiara Naro
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
| | - Ingrid Ehrmann
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Mikael Feracci
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, UK
| | | | - Alison Tyson-Capper
- Institute for Cellular Medicine, Newcastle University, Framlington Place, Newcastle NE2 4HH, UK
| | - Gavin J Clowry
- Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle, UK
| | - Philippe Fort
- Université Montpellier, UMR 5237, Centre de Recherche de Biologie cellulaire de Montpellier, CNRS, 34293 Montpellier, France
| | - Cyril Dominguez
- Leicester Institute of Structural and Chemical Biology and Department of Molecular and Cell Biology, Henry Wellcome Building, University of Leicester, Lancaster Road, Leicester LE1 7RH, UK
| | - Claudio Sette
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
| | - David J Elliott
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
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Abstract
STAR (signal transduction and activation of RNA) proteins regulate splicing of target genes that have roles in neural connectivity, survival and myelination in the vertebrate nervous system. These regulated splicing targets include mRNAs such as the Neurexins (Nrxn), SMN2 (survival of motor neuron) and MAG (myelin-associated glycoprotein). Recent work has made it possible to identify and validate STAR protein splicing targets in vivo by using genetically modified mouse models. In this review, we will discuss the importance of STAR protein splicing targets in the CNS (central nervous system).
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Li N, Hébert S, Song J, Kleinman CL, Richard S. Transcriptome profiling in preadipocytes identifies long noncoding RNAs as Sam68 targets. Oncotarget 2017; 8:81994-82005. [PMID: 29137239 PMCID: PMC5669865 DOI: 10.18632/oncotarget.17813] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 04/17/2017] [Indexed: 11/25/2022] Open
Abstract
The KH-type RNA binding protein Sam68 is required for adipogenesis. We have previously shown that Sam68-deficient mice have a lean phenotype and are protected against dietary-induced obesity due to defects in mTOR and S6K1 alternative splicing. Herein we profiled the transcriptome of Sam68 wild type and deficient 3T3-L1 mouse preadipocytes. We identified 652 protein-coding genes and 9 ncRNAs that were significantly altered with the loss of Sam68. As expected, downregulated genes were significantly associated with GO terms linked to cell migration, motility, and fat cell differentiation, while upregulated genes were mostly associated with GO terms linked to neurogenesis. Of the lncRNAs, we identified Hotair, Mir155hg, as well as two new lncRNAs (SR-lncRNA-1 and SR-lncRNA-2) that were regulated by Sam68, and contained consensus Sam68 binding sites. RNA stability assays showed that Sam68-deficiency decreased the half-life of Hotair, and increased the half-lives of Mir155hg and SR-lncRNA-2, while the stability of SR-lncRNA-1 was unaffected. Depletion of Hotair and SR-lncRNA-1 in wild type 3T3-L1 cells led to defects in adipogenesis, whereas depletion of SR-lncRNA-2 in Sam68-deficient 3T3-L1 cells partially rescued the adipogenesis defect observed in these cells. Collectively, our findings define a new role for Sam68 as a regulator of lncRNAs during adipogenic differentiation.
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Affiliation(s)
- Naomi Li
- Segal Cancer Center, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine, McGill University, Montréal, Québec H3A 1A1, Canada.,Department of Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
| | - Steven Hébert
- Segal Cancer Center, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Human Genetics, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Jingwen Song
- Segal Cancer Center, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine, McGill University, Montréal, Québec H3A 1A1, Canada.,Department of Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
| | - Claudia L Kleinman
- Segal Cancer Center, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Human Genetics, McGill University, Montréal, Québec H3A 1B1, Canada
| | - Stéphane Richard
- Segal Cancer Center, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada.,Department of Medicine, McGill University, Montréal, Québec H3A 1A1, Canada.,Department of Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
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Ding L, Zhang S, Xu M, Zhang R, Sui P, Yang Q. MicroRNA-27a contributes to the malignant behavior of gastric cancer cells by directly targeting PH domain and leucine-rich repeat protein phosphatase 2. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2017; 36:45. [PMID: 28327189 PMCID: PMC5361803 DOI: 10.1186/s13046-017-0516-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Accepted: 03/16/2017] [Indexed: 12/23/2022]
Abstract
Background Accumulating evidence indicates that microRNA-27a (miR-27a) is involved in carcinogenesis and tumor progression. However, the exact function and molecular mechanism of miR-27a in gastric cancer remain unclear. Methods Quantitative real-time PCR (qRT-PCR) was used to quantify the expression of miR-27a and its target gene. The function of miR-27a in gastric cancer was investigated through in vitro and in vivo assays (MTT assay, colony formation assay, flow cytometry assay, wound healing assay, migration and invasion assay, immunohistochemistry (IHC), immunofluorescence (IF) and Western blot). A luciferase reporter assay was conducted to confirm the target gene of miR-27a. Results We found that miR-27a was commonly overexpressed in gastric cancer and high expression of miR-27a was associated with distant metastasis, lymph node metastasis, advanced T stage and advanced clinical stage. Functional assays demonstrated that overexpression of miR-27a in AGS cells accelerated cell proliferation, migration and invasion and suppressed apoptosis. Meanwhile, opposite results were observed in SGC-7901 cells when miR-27a was suppressed. Consistently, down-regulation of miR-27a inhibited the growth and metastasis of engrafted tumors in vivo. Furthermore, we found PH domain and leucine-rich repeat protein phosphatase 2 (PHLPP2) to be a new target of miR-27a, and downregulation of PHLPP2 could rescue the effect of anti-miR-27a in gastric cancer cells. In addition, miR-27a-mediated suppression of PHLPP2 led to stimulation of the AKT/GSK3β pathway. Conclusions Our data suggest that miR-27a functions as a crucial oncogenic miRNA in gastric cancer. It can promote proliferation and metastasis of tumor cells by suppressing PHLPP2 and activating the AKT/GSK3β pathway. Therefore, miR-27a is a potential novel therapeutic target in gastric cancer treatment. Electronic supplementary material The online version of this article (doi:10.1186/s13046-017-0516-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lei Ding
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021, Jilin Province, China
| | - Shanyong Zhang
- Department of Orthopedics, The Second Hospital, Jilin University, Changchun, Jilin, China
| | - Mu Xu
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021, Jilin Province, China
| | - Renwen Zhang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021, Jilin Province, China
| | - Pengcheng Sui
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021, Jilin Province, China
| | - Qing Yang
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, 126 Xinmin Street, Changchun, 130021, Jilin Province, China.
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36
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La Rosa P, Bielli P, Compagnucci C, Cesari E, Volpe E, Farioli Vecchioli S, Sette C. Sam68 promotes self-renewal and glycolytic metabolism in mouse neural progenitor cells by modulating Aldh1a3 pre-mRNA 3'-end processing. eLife 2016; 5. [PMID: 27845622 PMCID: PMC5122457 DOI: 10.7554/elife.20750] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 11/14/2016] [Indexed: 12/20/2022] Open
Abstract
The balance between self-renewal and differentiation of neural progenitor cells (NPCs) dictates neurogenesis and proper brain development. We found that the RNA- binding protein Sam68 (Khdrbs1) is strongly expressed in neurogenic areas of the neocortex and supports the self-renewing potential of mouse NPCs. Knockout of Khdrbs1 constricted the pool of proliferating NPCs by accelerating their cell cycle exit and differentiation into post-mitotic neurons. Sam68 function was linked to regulation of Aldh1a3 pre-mRNA 3'-end processing. Binding of Sam68 to an intronic polyadenylation site prevents its recognition and premature transcript termination, favoring expression of a functional enzyme. The lower ALDH1A3 expression and activity in Khdrbs1-/- NPCs results in reduced glycolysis and clonogenicity, thus depleting the embryonic NPC pool and limiting cortical expansion. Our study identifies Sam68 as a key regulator of NPC self-renewal and establishes a novel link between modulation of ALDH1A3 expression and maintenance of high glycolytic metabolism in the developing cortex. DOI:http://dx.doi.org/10.7554/eLife.20750.001 Neurons develop from cells called neural progenitors. These cells can either divide to produce more progenitor cells or develop into specific types of neurons. These two activities – known as self-renewal and differentiation – must be balanced to produce the right number of specialized neurons, without depleting the pool of progenitor cells. The self-renewal and differentiation of progenitor cells is balanced by essentially regulating which genes are active, or expressed, within the cells. In the first step of gene expression, the genetic instructions are copied to form a molecule of pre-messenger RNA (or pre-mRNA for short). Each pre-mRNA molecule is then processed to produce a final product that can be translated into protein. Importantly, two copies of the same pre-mRNA may sometimes be processed in different ways, which allows multiple proteins to be produced from a single gene. RNA-binding proteins control pre-mRNA processing. The expression of one such protein, called Sam68, oscillates during the development of the nervous system, such that its expression peaks when there is intense production of new neurons and then declines. However, it was not known whether Sam68 actually helps neurons to develop. La Rosa et al. have now analysed the role of Sam68 in the developing brain of mice. The experiments confirmed that Sam68 is highly expressed in neural progenitor cells and showed that its levels dictate the cell’s fate: high expression encourages a cell to self-renew, while low expression triggers it to develop into a specialized neuron. Further investigation revealed that Sam68 works by promoting the expression of a metabolic enzyme called Aldehyde Dehydrogenase 1A3 or ALDH1A3. This enzyme promotes the release of energy from molecules of glucose via a process known as anaerobic glycolysis. La Rosa et al. found that cells that lack Sam68 make a truncated version of the pre-mRNA encoding ALDH1A3. This truncated pre-mRNA encodes a shortened version of the enzyme that is inactive. Further experiments confirmed that Sam68 normally prevents this from happening by binding to the pre-mRNA and processing it to produce the full-length, working version of the ALDH1A3 enzyme. Also, La Rosa et al. found that progenitor cells need working ALDH1A3 to keep them dividing, and to stop them from developing into specialized neurons too soon. Finally, because the processing of pre-RNA plays a major role in brain development, problems with this process often lead to intellectual disabilities and neurodegenerative diseases, such as autism spectrum disorder and amyotrophic lateral sclerosis. The next step following on from these new findings will be to investigate whether defects in Sam68 contribute to such conditions and, if so, to look for ways to counteract these defects. DOI:http://dx.doi.org/10.7554/eLife.20750.002
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Affiliation(s)
- Piergiorgio La Rosa
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, Rome, Italy
| | - Pamela Bielli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, Rome, Italy
| | - Claudia Compagnucci
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, Rome, Italy
| | - Eleonora Cesari
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, Rome, Italy
| | - Elisabetta Volpe
- Laboratory of Neuroimmunology, Fondazione Santa Lucia, Rome, Italy
| | | | - Claudio Sette
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy.,Laboratory of Neuroembryology, Fondazione Santa Lucia, Rome, Italy
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37
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Abstract
Alternative precursor-mRNA splicing is a key mechanism for regulating gene expression in mammals and is controlled by specialized RNA-binding proteins. The misregulation of splicing is implicated in multiple neurological disorders. We describe recent mouse genetic studies of alternative splicing that reveal its critical role in both neuronal development and the function of mature neurons. We discuss the challenges in understanding the extensive genetic programmes controlled by proteins that regulate splicing, both during development and in the adult brain.
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Affiliation(s)
- Celine K Vuong
- Molecular Biology Interdepartmental Graduate Program, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Douglas L Black
- Department of Microbiology, Immunology, and Molecular Genetics, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - Sika Zheng
- Division of Biomedical Sciences, University of California at Riverside, Riverside, California 92521, USA
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38
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Fu K, Sun X, Wier EM, Hodgson A, Liu Y, Sears CL, Wan F. Sam68/KHDRBS1 is critical for colon tumorigenesis by regulating genotoxic stress-induced NF-κB activation. eLife 2016; 5. [PMID: 27458801 PMCID: PMC4959885 DOI: 10.7554/elife.15018] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 06/29/2016] [Indexed: 12/19/2022] Open
Abstract
Nuclear factor kappa B (NF-κB)-mediated transcription is an important mediator for cellular responses to DNA damage. Genotoxic agents trigger a 'nuclear-to-cytoplasmic' NF-κB activation signaling pathway; however, the early nuclear signaling cascade linking DNA damage and NF-κB activation is poorly understood. Here we report that Src-associated-substrate-during-mitosis-of-68kDa/KH domain containing, RNA binding, signal transduction associated 1 (Sam68/KHDRBS1) is a key NF-κB regulator in genotoxic stress-initiated signaling pathway. Sam68 deficiency abolishes DNA damage-stimulated polymers of ADP-ribose (PAR) production and the PAR-dependent NF-κB transactivation of anti-apoptotic genes. Sam68 deleted cells are hypersensitive to genotoxicity caused by DNA damaging agents. Upregulated Sam68 coincides with elevated PAR production and NF-κB-mediated anti-apoptotic transcription in human and mouse colon cancer. Knockdown of Sam68 sensitizes human colon cancer cells to genotoxic stress-induced apoptosis and genetic deletion of Sam68 dampens colon tumor burden in mice. Together our data reveal a novel function of Sam68 in the genotoxic stress-initiated nuclear signaling, which is crucial for colon tumorigenesis. DOI:http://dx.doi.org/10.7554/eLife.15018.001 Cells use signaling pathways to detect and respond to harmful conditions by switching on genes that keep the cell healthy. One important pathway is the nuclear factor kappa B (NF-κB) signaling pathway, which is activated by many stimuli. These stimuli may come from infections from outside the cell or may originate inside the cell, as seen for DNA damage caused by irradiation, chemicals or rapid DNA replication in cancer cells. Most of a cell’s DNA is located in the cell nucleus. However, NF-κB proteins are normally located outside the nucleus, in the cell’s cytoplasm. Damage to DNA triggers a signal from the nucleus to the cytoplasm. This signal activates the NF-κB proteins, which move into the nucleus and turn on genes that help the cell to recover from the damage. These genes include those that prevent the cell from self-destructing. In one step of the NF-κB activation process, chain-like molecules called polymers are made from a compound called poly(ADP-ribose), or PAR for short. However, few other details are known about how the damaged DNA in the nucleus signals to the cytoplasm. A protein called Sam68, which is found in the cell nucleus, has been linked to DNA damage signaling. Fu, Sun et al. now present evidence that suggests that if mouse cells lack Sam68, they do not produce PAR polymers in response to DNA damage. In addition, these cells could not trigger the PAR-dependent signaling cascade that is essential for activating NF-κB and for turning on the protective genes. Consequently, cells that lacked Sam68 were extremely sensitive to agents that cause DNA damage, such as chemicals and irradiation. The NF-κB pathway is regulated incorrectly in some cancers, but is also activated by DNA damage caused by cancer treatments. Therefore, Fu, Sun et al. also explored the role of Sam68 in cancer. Reducing the levels of Sam68 made human colon cancer cells more likely to self-destruct when they were exposed to DNA-damaging agents. Furthermore, removing Sam68 from mice that spontaneously grow colon cancer caused their tumors to develop more slowly than mice that retained Sam68 in their cells. Overall, the findings presented by Fu, Sun et al. suggest that Sam68 regulates the signal from the nucleus to the cytoplasm that activates NF-κB proteins in response to DNA damage. Sam68 also appears to be important for helping colon cancer cells grow and survive. Future challenges will be to understand how Sam68 regulates the production of the PAR polymer in this response and to explore whether Sam68 can be targeted for treating cancer. DOI:http://dx.doi.org/10.7554/eLife.15018.002
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Affiliation(s)
- Kai Fu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Xin Sun
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Eric M Wier
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Andrea Hodgson
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States.,W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, John Hopkins University, Baltimore, United States
| | - Yue Liu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States
| | - Cynthia L Sears
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, John Hopkins University, Baltimore, United States.,Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, United States.,Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, United States
| | - Fengyi Wan
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, United States.,Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins Medical Institutions, Baltimore, United States
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39
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Sam68 is a regulator of Toll-like receptor signaling. Cell Mol Immunol 2016; 14:107-117. [PMID: 27374795 PMCID: PMC5214940 DOI: 10.1038/cmi.2016.32] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 05/14/2016] [Accepted: 05/15/2016] [Indexed: 12/17/2022] Open
Abstract
Recognition of pathogens by Toll-like receptors (TLR) activate multiple signaling cascades and expression of genes tailored to mount a primary immune response, inflammation, cell survival and apoptosis. Although TLR-induced activation of pathways, such as nuclear factor kappaB (NF-κB) and mitogen-activated protein kinases (MAPK), has been well studied, molecular entities controlling quantitative regulation of these pathways during an immune response remain poorly defined. We identified Sam68 as a novel regulator of TLR-induced NF-κB and MAPK activation. We found that TLR2 and TLR3 are totally dependent, whereas TLR4 is only partially dependent on Sam68 to induce the activation of NF-κB c-Rel. Absence of Sam68 greatly decreased TLR2- and TLR3-induced NF-κB p65 activation, whereas TLR4-induced p65 activation in a Sam68-independent manner. In contrast, Sam68 appeared to be a negative regulator of MAPK pathways because absence of Sam68 enhanced TLR2-induced activation of extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK). Interestingly, TLR2- and TLR3-induced gene expression showed a differential requirement of Sam68. Absence of Sam68 impaired TLR2-induced gene expression, suggesting that Sam68 has a critical role in myeloid differentiation primary response gene 88-dependent TLR2 signaling. TLR3-induced gene expression that utilize Toll/Interleukin-1 receptor-domain-containing adapter-inducing beta interferon pathway, depend only partially on Sam68. Our findings suggest that Sam68 may function as an immune rheostat that balances the activation of NF-κB p65 and c-Rel, as well as MAPK, revealing a potential novel target to manipulate TLR signaling.
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Li N, Richard S. Sam68 functions as a transcriptional coactivator of the p53 tumor suppressor. Nucleic Acids Res 2016; 44:8726-8741. [PMID: 27365047 PMCID: PMC5062974 DOI: 10.1093/nar/gkw582] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 06/18/2016] [Indexed: 02/07/2023] Open
Abstract
Sam68 is a known sequence-specific RNA binding protein that regulates alternative splicing events during the cell cycle and apoptosis. Sam68 has also been shown to influence transcription, but the molecular mechanism remains undefined. Herein we identify Sam68 as a transcriptional coactivator of the p53 tumor suppressor in response to DNA damage. Using CRISPR/Cas9 generated isogenic HCT116 Sam68−/− cell lines wild type or deficient for p53, we show that Sam68 is required for the efficient transactivation of p53 target genes. Consistently, Sam68 depletion caused defects in DNA damage-induced cell cycle arrest and apoptosis mediated by p53. Mechanistically, we demonstrate that Sam68 physically interacted with p53 in an RNA-dependent manner, and that this interaction was essential for the coactivator function of Sam68. Furthermore, we show that both Sam68 and p53 were recruited to promoters of p53-responsive genes, suggesting interdependence. Finally, Sam68 acted in concert with the p53 long noncoding RNA (lncRNA) target PR-lncRNA-1 for p53 recruitment, implicating a positive-feedback mechanism in which lncRNAs induced by the Sam68/p53 complex can enhance p53 transcriptional activity. These findings define a hitherto novel mechanism of action for Sam68 in governing p53 transcriptional activation, and represent the first report of Sam68 in the regulation of tumor suppressor activities.
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Affiliation(s)
- Naomi Li
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
| | - Stéphane Richard
- Terry Fox Molecular Oncology Group and the Bloomfield Center for Research on Aging, Sir Mortimer B Davis Jewish General Hospital, Lady Davis Institute for Medical Research, Montréal, Québec H3T 1E2, Canada Department of Medicine and Oncology, McGill University, Montréal, Québec H3A 1A1, Canada
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Wu W, Liu Y, Wang Y. Sam68 promotes Schwann cell proliferation by enhancing the PI3K/Akt pathway and acts on regeneration after sciatic nerve crush. Biochem Biophys Res Commun 2016; 473:1045-1051. [DOI: 10.1016/j.bbrc.2016.04.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 04/04/2016] [Indexed: 12/14/2022]
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Ladd AN. New Insights Into the Role of RNA-Binding Proteins in the Regulation of Heart Development. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:125-85. [PMID: 27017008 DOI: 10.1016/bs.ircmb.2015.12.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The regulation of gene expression during development takes place both at the transcriptional and posttranscriptional levels. RNA-binding proteins (RBPs) regulate pre-mRNA processing, mRNA localization, stability, and translation. Many RBPs are expressed in the heart and have been implicated in heart development, function, or disease. This chapter will review the current knowledge about RBPs in the developing heart, focusing on those that regulate posttranscriptional gene expression. The involvement of RBPs at each stage of heart development will be considered in turn, including the establishment of specific cardiac cell types and formation of the primitive heart tube, cardiac morphogenesis, and postnatal maturation and aging. The contributions of RBPs to cardiac birth defects and heart disease will also be considered in these contexts. Finally, the interplay between RBPs and other regulatory factors in the developing heart, such as transcription factors and miRNAs, will be discussed.
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Affiliation(s)
- A N Ladd
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America.
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The RNA-binding protein Sam68 regulates tumor cell viability and hepatic carcinogenesis by inhibiting the transcriptional activity of FOXOs. J Mol Histol 2015; 46:485-97. [PMID: 26438629 DOI: 10.1007/s10735-015-9639-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 09/30/2015] [Indexed: 12/31/2022]
Abstract
Src associated in mitosis (Sam68; 68 kDa) is a KH domain RNA-binding protein that belongs to the signal transduction and activation of RNA family, and has been implicated in the oncogenesis and progression of several human cancers. Our study aimed to investigated the clinicopathologic significance of Sam68 expression and its role in cell proliferation and the underlying molecular mechanism in hepatocellular carcinoma (HCC). We demonstrated that Sam68 expression was significantly increased in HCC and high expression of Sam68 was significantly associated with Edmondson grade, tumor size, tumor nodule number, HBsAg status and Ki-67 expression. The Kaplan-Meier survival curves showed that increased expression of Sam68 was correlated with poor prognosis in HCC patients and served as an independent prognostic marker of overall survival in a multivariable analysis. In addition, through serum starvation and refeeding assay, we demonstrated that Sam68 was lowly expressed in serum-starved HCC cells, and was progressively increased after serum-additioning. Furthermore, siRNA knockdown of endogenous Sam68 inhibited cell proliferation and tumourigenicity of HCC cells in vitro, through blocking the G1 to S phase transition. Moreover, we reported that the anti-proliferative effect of silencing Sam68 was accompanied with up-regulated expression of cyclin-dependent kinase inhibitors, p21(Cip1) and p27(Kip1), enhanced transactivation of FOXO factors (FOXO4), and dysreuglation of Akt/GSK-3β signaling. Taken together, these findings provide a rational framework for the progression of HCC and thereby indicated that Sam68 might be a novel and useful prognostic marker and a potential target for human HCC treatment.
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Pagliarini V, Pelosi L, Bustamante MB, Nobili A, Berardinelli MG, D'Amelio M, Musarò A, Sette C. SAM68 is a physiological regulator of SMN2 splicing in spinal muscular atrophy. J Cell Biol 2015; 211:77-90. [PMID: 26438828 PMCID: PMC4602033 DOI: 10.1083/jcb.201502059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 08/31/2015] [Indexed: 02/05/2023] Open
Abstract
Knockout of the splicing factor SAM68 promotes SMN2 splicing, improving neuromuscular defects and viability in SMA mice. Spinal muscular atrophy (SMA) is a neurodegenerative disease caused by loss of motor neurons in patients with null mutations in the SMN1 gene. The almost identical SMN2 gene is unable to compensate for this deficiency because of the skipping of exon 7 during pre–messenger RNA (mRNA) processing. Although several splicing factors can modulate SMN2 splicing in vitro, the physiological regulators of this disease-causing event are unknown. We found that knockout of the splicing factor SAM68 partially rescued body weight and viability of SMAΔ7 mice. Ablation of SAM68 function promoted SMN2 splicing and expression in SMAΔ7 mice, correlating with amelioration of SMA-related defects in motor neurons and skeletal muscles. Mechanistically, SAM68 binds to SMN2 pre-mRNA, favoring recruitment of the splicing repressor hnRNP A1 and interfering with that of U2AF65 at the 3′ splice site of exon 7. These findings identify SAM68 as the first physiological regulator of SMN2 splicing in an SMA mouse model.
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Affiliation(s)
- Vittoria Pagliarini
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
| | - Laura Pelosi
- Institute Pasteur Cenci-Bolognetti Foundation, DAHFMO-Unit of Histology and Medical Embryology, IIM, University of Rome La Sapienza, 00161 Rome, Italy
| | - Maria Blaire Bustamante
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
| | - Annalisa Nobili
- Laboratory of Molecular Neuroscience, Fondazione Santa Lucia, 00143 Rome, Italy Medical School University Campus Bio-Medico, 00128 Rome, Italy
| | - Maria Grazia Berardinelli
- Institute Pasteur Cenci-Bolognetti Foundation, DAHFMO-Unit of Histology and Medical Embryology, IIM, University of Rome La Sapienza, 00161 Rome, Italy
| | - Marcello D'Amelio
- Laboratory of Molecular Neuroscience, Fondazione Santa Lucia, 00143 Rome, Italy Medical School University Campus Bio-Medico, 00128 Rome, Italy
| | - Antonio Musarò
- Institute Pasteur Cenci-Bolognetti Foundation, DAHFMO-Unit of Histology and Medical Embryology, IIM, University of Rome La Sapienza, 00161 Rome, Italy Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, 00161 Rome, Italy
| | - Claudio Sette
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, 00133 Rome, Italy Laboratory of Neuroembryology, Fondazione Santa Lucia, 00143 Rome, Italy
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SAM68: Signal Transduction and RNA Metabolism in Human Cancer. BIOMED RESEARCH INTERNATIONAL 2015; 2015:528954. [PMID: 26273626 PMCID: PMC4529925 DOI: 10.1155/2015/528954] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/24/2015] [Indexed: 12/21/2022]
Abstract
Alterations in expression and/or activity of splicing factors as well as mutations in cis-acting
splicing regulatory sequences contribute to cancer phenotypes. Genome-wide
studies have revealed more than 15,000 tumor-associated splice variants derived from
genes involved in almost every aspect of cancer cell biology, including proliferation,
differentiation, cell cycle control, metabolism, apoptosis, motility, invasion, and
angiogenesis. In the past decades, several RNA binding proteins (RBPs) have been
implicated in tumorigenesis. SAM68 (SRC associated in mitosis of 68 kDa) belongs to
the STAR (signal transduction and activation of RNA metabolism) family of RBPs.
SAM68 is involved in several steps of mRNA metabolism, from transcription to
alternative splicing and then to nuclear export. Moreover, SAM68 participates in signaling
pathways associated with cell response to stimuli, cell cycle transitions, and viral
infections. Recent evidence has linked this RBP to the onset and progression of
different tumors, highlighting misregulation of SAM68-regulated splicing events as a
key step in neoplastic transformation and tumor progression. Here we review recent
studies on the role of SAM68 in splicing regulation and we discuss its contribution to
aberrant pre-mRNA processing in cancer.
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Zhou J, Cheng M, Boriboun C, Ardehali MM, Jiang C, Liu Q, Han S, Goukassian DA, Tang YL, Zhao TC, Zhao M, Cai L, Richard S, Kishore R, Qin G. Inhibition of Sam68 triggers adipose tissue browning. J Endocrinol 2015; 225:181-9. [PMID: 25934704 PMCID: PMC4482239 DOI: 10.1530/joe-14-0727] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/22/2015] [Indexed: 12/12/2022]
Abstract
Obesity is associated with insulin resistance and type 2 diabetes; molecular mechanisms that promote energy expenditure can be utilized for effective therapy. Src-associated in mitosis of 68 kDa (Sam68) is potentially significant, because knockout (KO) of Sam68 leads to markedly reduced adiposity. In the present study, we sought to determine the mechanism by which Sam68 regulates adiposity and energy homeostasis. We first found that Sam68 KO mice have a significantly reduced body weight as compared to controls, and the difference is explained entirely by decreased adiposity. Interestingly, these effects were not mediated by a difference in food intake; rather, they were associated with enhanced physical activity. When they were fed a high-fat diet, Sam68 KO mice gained much less body weight and fat mass than their WT littermates did, and they displayed an improved glucose and insulin tolerance. In Sam68 KO mice, the brown adipose tissue (BAT), inguinal, and epididymal depots were smaller, and their adipocytes were less hypertrophied as compared to their WT littermates. The BAT of Sam68 KO mice exhibited reduced lipid stores and expressed higher levels of Ucp1 and key thermogenic and fatty acid oxidation genes. Similarly, depots of inguinal and epididymal white adipose tissue (WAT) in Sam68 KO mice appeared browner, their multilocular Ucp1-positive cells were much more abundant, and the expression of Ucp1, Cidea, Prdm16, and Ppargc1a genes was greater as compared to WT controls, which suggests that the loss of Sam68 also promotes WAT browning. Furthermore, in all of the fat depots of the Sam68 KO mice, the expression of M2 macrophage markers was up-regulated, and that of M1 markers was down-regulated. Thus, Sam68 plays a crucial role in controlling thermogenesis and may be targeted to combat obesity and associated disorders.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Adipogenesis
- Adipose Tissue, Brown/cytology
- Adipose Tissue, Brown/immunology
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, Brown/pathology
- Adipose Tissue, White/cytology
- Adipose Tissue, White/immunology
- Adipose Tissue, White/metabolism
- Adipose Tissue, White/pathology
- Adiposity
- Animals
- Behavior, Animal
- Cell Size
- Disease Resistance
- Energy Intake
- Energy Metabolism
- Gene Expression Regulation
- Heterozygote
- Insulin Resistance
- Ion Channels/biosynthesis
- Macrophages/immunology
- Male
- Mice, Inbred C57BL
- Mice, Knockout
- Mitochondrial Proteins/biosynthesis
- Motor Activity
- Obesity/immunology
- Obesity/metabolism
- Obesity/pathology
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Thermogenesis
- Uncoupling Protein 1
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Affiliation(s)
- Junlan Zhou
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Min Cheng
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Chan Boriboun
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Mariam M Ardehali
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Changfei Jiang
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Qinghua Liu
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Shuling Han
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - David A Goukassian
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Yao-Liang Tang
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ting C Zhao
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Ming Zhao
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Lu Cai
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Stéphane Richard
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Raj Kishore
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
| | - Gangjian Qin
- Department of Medicine-Cardiology Feinberg Cardiovascular Research Institute, Northwestern University Feinberg School of Medicine, 303 E Chicago Avenue, Tarry 14-721, Chicago, Illinois 60611, USA Department of Cardiology Tongji Medical College, Union Hospital, Huazhong University of Science and Technology, Wuhan, Hubei, China Department of Biochemistry University of Ottawa, Ottawa, Ontario, Canada Institute for Medical Biology and Hubei Provincial Key Laboratory for Protection and Application of Special Plants in Wuling Area of China College of Life Sciences, South-Central University for Nationalities, Wuhan, Hubei, China GeneSys Research Institute CardioVascular Research Center, Tufts University School of Medicine, Boston, Massachusetts, USA Department of Medicine Medical College of Georgia, Vascular Biology Center, Georgia Regents University, Augusta, Georgia, USA Department of Surgery Roger Williams Medical Center, Boston University Medical School, Providence, Rhode Island, USA Kosair Children Hospital Research Institute Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology, University of Louisville, Louisville, Kentucky, USA Lady Davis Institute for Medical Research McGill University, Montreal, Quebec, Canada Center for Translational Medicine Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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47
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Abstract
Newborn offspring of the inbred mouse RR/Sgn strain have a low survival rate prior to
weaning. We hypothesized that this is a consequence of an inferior nurturing ability of
RR/Sgn mothers and that RR/Sgn mothers have a tendency to lose their pups. We performed
quantitative trait locus (QTL) mapping for inferior nurturing ability and tendency to lose
pups in RR/Sgn mothers. The number of pups was adjusted to 6 per dam on the day of
delivery, and the number of surviving pups and their total weight (litter weight) were
scored at 12 days after birth. Nurturing ability was evaluated by litter weight, and
tendency to lose pups was evaluated by scoring whether or not the mothers lost their pups.
For litter weight, we identified one significant QTL on chromosome 4 and three suggestive
QTLs on chromosomes 7, 9 and 17. The RR/Sgn allele was associated with lower litter weight
at all loci. For the tendency to lose pups, we identified three suggestive QTLs on
chromosomes 4, 9 and 16. The RR/Sgn allele was associated with an increased tendency to
lose pups at all loci. These results supported our hypothesis that the low survival rate
phenotype was attributable, at least in part, to a phenotype whereby mothers display
inferior nurturing ability and a tendency to lose pups. Thus, it suggests that these two
traits share genetic basis.
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Affiliation(s)
- Jun-ichi Suto
- Agrogenomics Research Center, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan
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Li LJ, Zhang FB, Liu SY, Tian YH, Le F, Lou HY, Huang HF, Jin F. Decreased expression of SAM68 in human testes with spermatogenic defects. Fertil Steril 2014; 102:61-67.e3. [PMID: 24794312 DOI: 10.1016/j.fertnstert.2014.03.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 03/02/2014] [Accepted: 03/20/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To assess the expression patterns of SAM68 in the testes of azoospermic patients with normal and abnormal spermatogenesis. DESIGN Retrospective study and in vitro study. SETTING University hospital. PATIENT(S) Testicular biopsies of azoospermic men with normal spermatogenesis (OAZ; n=20), with maturation arrest at the spermatocyte stage (MA; n=20), and with Sertoli cell-only syndrome (SCOS; n=10). INTERVENTION(S) No interventions with patients. Knockdown of Sam68 was performed in the GC-2spd(ts) cell line. MAIN OUTCOME MEASURE(S) SAM68 expression was analyzed using quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry analysis in tissues. Moreover, Sam68 was knocked down in GC-2spd(ts) cells. Cell viability was measured using the MTT assay, and the apoptosis rate was detected using flow cytometry with the Annexin V-FITC kit. RESULT(S) Using qRT-PCR, the expression level of testicular SAM68 mRNA in MA and SCOS patients was statistically reduced compared with in OAZ patients. In addition, using qRT-PCR, Western blot, and immunohistochemistry analyses, mRNA and protein expressions of SAM68 were absent or barely detectable in testicular tissues in 45% (9 of 20) of patients with MA and in all patients with SCOS. Furthermore, decreased expression of Sam68 suppressed germ cell proliferation and induced apoptosis in transfected GC-2spd(ts) cells. CONCLUSION(S) Deficient SAM68 expression was observed in the human testis with MA at the spermatocyte stage and SCOS. These results may offer new perspectives on the molecular basis of abnormal spermatogenesis.
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Affiliation(s)
- Le-Jun Li
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Feng-Bin Zhang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Shu-Yuan Liu
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Yong-Hong Tian
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Fang Le
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Hang-Ying Lou
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - He-Feng Huang
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China
| | - Fan Jin
- Department of Reproductive Endocrinology, Women's Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, People's Republic of China; Key Laboratory of Reproductive Genetics, National Ministry of Education (Zhejiang University), Women's Reproductive Health Laboratory of Zhejiang Province, Hangzhou, Zhejiang, People's Republic of China.
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Iijima T, Iijima Y, Witte H, Scheiffele P. Neuronal cell type-specific alternative splicing is regulated by the KH domain protein SLM1. ACTA ACUST UNITED AC 2014; 204:331-42. [PMID: 24469635 PMCID: PMC3912522 DOI: 10.1083/jcb.201310136] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cell type–specific expression of the splicing regulator SLM1 provides a mechanism for shaping the molecular repertoires of synaptic adhesion molecules in neuronal populations in vivo. The unique functional properties and molecular identity of neuronal cell populations rely on cell type–specific gene expression programs. Alternative splicing represents a powerful mechanism for expanding the capacity of genomes to generate molecular diversity. Neuronal cells exhibit particularly extensive alternative splicing regulation. We report a highly selective expression of the KH domain–containing splicing regulators SLM1 and SLM2 in the mouse brain. Conditional ablation of SLM1 resulted in a severe defect in the neuronal isoform content of the polymorphic synaptic receptors neurexin-1, -2, and -3. Thus, cell type–specific expression of SLM1 provides a mechanism for shaping the molecular repertoires of synaptic adhesion molecules in neuronal populations in vivo.
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50
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Sánchez-Jiménez F, Sánchez-Margalet V. Role of Sam68 in post-transcriptional gene regulation. Int J Mol Sci 2013; 14:23402-19. [PMID: 24287914 PMCID: PMC3876053 DOI: 10.3390/ijms141223402] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/11/2013] [Accepted: 11/13/2013] [Indexed: 01/10/2023] Open
Abstract
The STAR family of proteins links signaling pathways to various aspects of post-transcriptional regulation and processing of RNAs. Sam68 belongs to this class of heteronuclear ribonucleoprotein particle K (hnRNP K) homology (KH) single domain-containing family of RNA-binding proteins that also contains some domains predicted to bind critical components in signal transduction pathways. In response to phosphorylation and other post-transcriptional modifications, Sam68 has been shown to have the ability to link signal transduction pathways to downstream effects regulating RNA metabolism, including transcription, alternative splicing or RNA transport. In addition to its function as a docking protein in some signaling pathways, this prototypic STAR protein has been identified to have a nuclear localization and to take part in the formation of both nuclear and cytosolic multi-molecular complexes such as Sam68 nuclear bodies and stress granules. Coupling with other proteins and RNA targets, Sam68 may play a role in the regulation of differential expression and mRNA processing and translation according to internal and external signals, thus mediating important physiological functions, such as cell death, proliferation or cell differentiation.
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Affiliation(s)
- Flora Sánchez-Jiménez
- Department of Medical Biochemistry and Molecular Biology and Immunology, UGC Clinical Biochemistry, Virgen Macarena University Hospital, Avenue. Sánchez Pizjuan 4, Medical School, University of Seville, Seville 41009, Spain.
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