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Tran Q, Lee H, Jung JH, Chang SH, Shrestha R, Kong G, Park J, Kim SH, Park KS, Rhee HW, Yun J, Cho MH, Kim KP, Park J. Emerging role of LETM1/GRP78 axis in lung cancer. Cell Death Dis 2022; 13:543. [PMID: 35680871 PMCID: PMC9184611 DOI: 10.1038/s41419-022-04993-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 05/26/2022] [Accepted: 05/31/2022] [Indexed: 01/21/2023]
Abstract
The selective autophagy of damaged mitochondria is called mitophagy. Mitochondrial dysfunction, mitophagy, and apoptosis have been suggested to be interrelated in various human lung carcinomas. Leucine zipper EF-hand-containing transmembrane protein-1 (LETM1) was cloned in an attempt to identify candidate genes for Wolf-Hirschhorn syndrome. LETM1 plays a role in mitochondrial morphology, ion homeostasis, and cell viability. LETM1 has also been shown to be overexpressed in different human cancer tissues, including lung cancer. In the current study, we have provided clear evidence that LETM1 acts as an anchoring protein for the mitochondria-associated ER membrane (MAM). Fragmented mitochondria have been found in lung cancer cells with LETM1 overexpression. In addition, a reduction of mitochondrial membrane potential and significant accumulation of microtubule-associated protein 1 A/1B-light chain 3 punctate, which localizes with Red-Mito, was found in LETM1-overexpressed cells, suggesting that mitophagy is upregulated in these cells. Interestingly, glucose-regulated protein 78 kDa (GRP78; an ER chaperon protein) and glucose-regulated protein 75 kDa (GRP75) were posited to interact with LETM1 in the immunoprecipitated LETM1 of H460 cells. This interaction was enhanced in cells treated with carbonyl cyanide m-chlorophenylhydrazone, a chemical mitophagy inducer. Treatment of cells with honokiol (a GRP78 inhibitor) blocked LETM1-mediated mitophagy, and CRISPR/Cas9-mediated GRP75 knockout inhibited LETM1-induced autophagy. Thus, GRP78 interacts with LETM1. Taken together, these observations support the notion that the complex formation of LETM1/GRP75/GRP78 might be an important step in MAM formation and mitophagy, thus regulating mitochondrial quality control in lung cancer.
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Affiliation(s)
- Quangdon Tran
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,Molecular Biology Laboratory, Department of Medical Laboratories, Hai Phong International Hospital, Hai Phong City, #18000 Vietnam
| | - Hyunji Lee
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea
| | - Jae Hun Jung
- grid.289247.20000 0001 2171 7818Department of Applied Chemistry, College of Applied Sciences, Kyunghee University, Yongin, 17104 South Korea
| | - Seung-Hee Chang
- grid.31501.360000 0004 0470 5905Laboratory of Toxicology, College of Veterinary Medicine Seoul National University, Seoul, 08826 South Korea
| | - Robin Shrestha
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea
| | - Gyeyeong Kong
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea
| | - Jisoo Park
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.411948.10000 0001 0523 5122Department of Life Science, Hyehwa Liberal Arts College, Daejeon University, Daejeon, 34520 South Korea
| | - Seon-Hwan Kim
- grid.254230.20000 0001 0722 6377Department of Neurosurgery, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea
| | - Kyu-Sang Park
- grid.15444.300000 0004 0470 5454Department of Physiology and Institute of Lifestyle Medicine, Yonsei University Wonju College of Medicine, Wonju, 26427 Korea
| | - Hyun-Woo Rhee
- grid.42687.3f0000 0004 0381 814XDepartment of Chemistry, Ulsan National Institute of Science and Technology, Ulsan, 44919 Korea
| | - Jeanho Yun
- grid.255166.30000 0001 2218 7142Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, 49201 South Korea
| | - Myung-Haing Cho
- grid.31501.360000 0004 0470 5905Laboratory of Toxicology, College of Veterinary Medicine Seoul National University, Seoul, 08826 South Korea ,RNABIO, Seongnam, Gyeonggi-do 13201 South Korea
| | - Kwang Pyo Kim
- grid.289247.20000 0001 2171 7818Department of Applied Chemistry, College of Applied Sciences, Kyunghee University, Yongin, 17104 South Korea
| | - Jongsun Park
- grid.254230.20000 0001 0722 6377Department of Pharmacology, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea ,grid.254230.20000 0001 0722 6377Department of Medical Science, Metabolic Syndrome and Cell Signaling Laboratory, Institute for Cancer Research, College of Medicine, Chungnam National University, Daejeon, 35015 South Korea
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Abstract
The uptake of calcium into and extrusion of calcium from the mitochondrial matrix is a fundamental biological process that has critical effects on cellular metabolism, signaling, and survival. Disruption of mitochondrial calcium (mCa2+) cycling is implicated in numerous acquired diseases such as heart failure, stroke, neurodegeneration, diabetes, and cancer, and is genetically linked to several inherited neuromuscular disorders. Understanding the mechanisms responsible for mCa2+ exchange therefore holds great promise for the treatment of these diseases. The past decade has seen the genetic identification of many of the key proteins that mediate mitochondrial calcium uptake and efflux. Here, we present an overview of the phenomenon of mCa2+ transport, and a comprehensive examination of the molecular machinery that mediates calcium flux across the inner mitochondrial membrane: the mitochondrial uniporter complex (consisting of MCU, EMRE, MICU1, MICU2, MICU3, MCUB, and MCUR1), NCLX, LETM1, the mitochondrial ryanodine receptor, and the mitochondrial permeability transition pore. We then consider the physiological implications of mCa2+ flux and evaluate how alterations in mCa2+ homeostasis contribute to human disease. This review concludes by highlighting opportunities and challenges for therapeutic intervention in pathologies characterized by aberrant mCa2+ handling and by summarizing critical unanswered questions regarding the biology of mCa2+ flux.
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Affiliation(s)
- Joanne F Garbincius
- Center for Translational Medicine, Center for Translational Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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3
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Loss-of-function and missense variants in NSD2 cause decreased methylation activity and are associated with a distinct developmental phenotype. Genet Med 2021; 23:1474-1483. [PMID: 33941880 PMCID: PMC8354849 DOI: 10.1038/s41436-021-01158-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 11/16/2022] Open
Abstract
Purpose Despite a few recent reports of patients harboring truncating variants in NSD2, a gene considered critical for the Wolf–Hirschhorn syndrome (WHS) phenotype, the clinical spectrum associated with NSD2 pathogenic variants remains poorly understood. Methods We collected a comprehensive series of 18 unpublished patients carrying heterozygous missense, elongating, or truncating NSD2 variants; compared their clinical data to the typical WHS phenotype after pooling them with ten previously described patients; and assessed the underlying molecular mechanism by structural modeling and measuring methylation activity in vitro. Results The core NSD2-associated phenotype includes mostly mild developmental delay, prenatal-onset growth retardation, low body mass index, and characteristic facial features distinct from WHS. Patients carrying missense variants were significantly taller and had more frequent behavioral/psychological issues compared with those harboring truncating variants. Structural in silico modeling suggested interference with NSD2’s folding and function for all missense variants in known structures. In vitro testing showed reduced methylation activity and failure to reconstitute H3K36me2 in NSD2 knockout cells for most missense variants. Conclusion NSD2 loss-of-function variants lead to a distinct, rather mild phenotype partially overlapping with WHS. To avoid confusion for patients, NSD2 deficiency may be named Rauch–Steindl syndrome after the delineators of this phenotype.
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Natarajan GK, Mishra J, Camara AKS, Kwok WM. LETM1: A Single Entity With Diverse Impact on Mitochondrial Metabolism and Cellular Signaling. Front Physiol 2021; 12:637852. [PMID: 33815143 PMCID: PMC8012663 DOI: 10.3389/fphys.2021.637852] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/25/2021] [Indexed: 12/11/2022] Open
Abstract
Nearly 2 decades since its discovery as one of the genes responsible for the Wolf-Hirschhorn Syndrome (WHS), the primary function of the leucine-zipper EF-hand containing transmembrane 1 (LETM1) protein in the inner mitochondrial membrane (IMM) or the mechanism by which it regulates mitochondrial Ca2+ handling is unresolved. Meanwhile, LETM1 has been associated with the regulation of fundamental cellular processes, such as development, cellular respiration and metabolism, and apoptosis. This mini-review summarizes the diversity of cellular functions impacted by LETM1 and highlights the multiple roles of LETM1 in health and disease.
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Affiliation(s)
- Gayathri K Natarajan
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Jyotsna Mishra
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Amadou K S Camara
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Wai-Meng Kwok
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI, United States.,Cancer Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, United States.,Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, United States
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5
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Zhang Y, Chen L, Cao Y, Chen S, Xu C, Xing J, Zhang K. LETM1 Promotes Gastric Cancer Cell Proliferation, Migration, and Invasion via the PI3K/Akt Signaling Pathway. J Gastric Cancer 2020; 20:139-151. [PMID: 32595998 PMCID: PMC7311216 DOI: 10.5230/jgc.2020.20.e12] [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: 11/27/2019] [Revised: 03/04/2020] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Purpose Globally, there is a high incidence of gastric cancer (GC). Leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is reported to play a vital role in several human malignancies. However, there is limited understanding of the role of LETM1 in GC. This study aims to investigate the effects of LETM1 on proliferation, migration, and invasion of GC cells. Materials and Methods The expression levels of LETM1 in the normal gastric mucosal epithelial cells (GES-1) and GC cells were analyzed by quantitative real-time polymerase chain reaction and western blotting. CCK-8, wound healing, and Transwell invasion assays were performed to evaluate the effect of LETM1 knockdown or overexpression on the proliferation, migration, and invasion of the GC cells, respectively. Additionally, the effect of LETM1 knockdown or overexpression on GC cell apoptosis was determined by flow cytometry. Furthermore, the effect of LETM1 knockdown or overexpression on the expression levels of PI3K/Akt signaling pathway-related proteins was evaluated by western blotting. Results The GC cells exhibited markedly higher mRNA and protein expression levels of LETM1 than the GES-1 cells. Additionally, the knockdown of LETM1 remarkably suppressed the GC cell proliferation, migration, and invasion, and promoted the apoptosis of GC cells, which were reversed upon LETM1 overexpression. Furthermore, the western blotting analysis indicated that LETM1 facilitates GC progression via the PI3K/Akt signaling pathway. Conclusions LETM1 acts as an oncogenic gene to promote GC cell proliferation, migration, and invasion via the PI3K/Akt signaling pathway. Therefore, LETM1 may be a potential target for GC diagnosis and treatment.
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Affiliation(s)
- Yunfeng Zhang
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Lele Chen
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Yifan Cao
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Si Chen
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Chao Xu
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Jun Xing
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
| | - Kaiguang Zhang
- Department of Gastroenterology, The Affiliated Provincial Hospital of Anhui Medical University, Hefei, China
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6
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Aral C, Demirkesen S, Bircan R, Yasar Sirin D. Melatonin reverses the oxidative stress and mitochondrial dysfunction caused by LETM1 silencing. Cell Biol Int 2019; 44:795-807. [PMID: 31777134 DOI: 10.1002/cbin.11274] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 11/25/2019] [Indexed: 12/28/2022]
Abstract
LETM1 is a mitochondrial inner-membrane protein, which is encoded by a gene present in a locus of 4p, which, in turn, is deleted in the Wolf-Hirschhorn Syndrome, and is assumed to be related to its pathogenesis. The cellular damage caused by the deletion is presumably related to oxidative stress. Melatonin has many beneficial roles in protecting mitochondria by scavenging reactive oxygen species, maintaining membrane potential, and improving functions. The aim of this study was to investigate the effects of melatonin administration to LETM1-silenced mouse embryonic fibroblast cells as a cellular model for LETM1 deficiency. We transfected mouse embryonic fibroblast cells with a pair of siRNA against LETM1 and monitored the oxidative stress and mitochondrial functions with or without melatonin addition. MnSOD expression and aconitase activity decreased and oxidized protein levels increased in LETM1-silenced cells. LETM1 suppression did not alter the expression of OXPHOS complexes, but the oxygen consumption rates decreased significantly; however, this change was not related to complex I but instead involved complex IV and complex II. Melatonin supplementation effectively normalized the parameters studied, including the oxygen consumption rate. Our findings identified a novel effect of LETM1 deficiency on cellular respiration via complex II as well as a potential beneficial role of melatonin treatment. On the other hand, these effects may be specific to the cell line used and need to be verified in other cell lines.
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Affiliation(s)
- Cenk Aral
- Department of Molecular Biology and Genetics, Faculty of Science and Arts, Namık Kemal University, 59030, Tekirdağ, Turkey
| | - Seyma Demirkesen
- Department of Molecular Biology and Genetics, Faculty of Science and Arts, Namık Kemal University, 59030, Tekirdağ, Turkey
| | - Rıfat Bircan
- Department of Molecular Biology and Genetics, Faculty of Science and Arts, Namık Kemal University, 59030, Tekirdağ, Turkey
| | - Duygu Yasar Sirin
- Department of Molecular Biology and Genetics, Faculty of Science and Arts, Namık Kemal University, 59030, Tekirdağ, Turkey
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Nevado J, Ho KS, Zollino M, Blanco R, Cobaleda C, Golzio C, Beaudry‐Bellefeuille I, Berrocoso S, Limeres J, Barrúz P, Serrano‐Martín C, Cafiero C, Málaga I, Marangi G, Campos‐Sánchez E, Moriyón‐Iglesias T, Márquez S, Markham L, Twede H, Lortz A, Olson L, Sheng X, Weng C, Wassman ER, Newcomb T, Wassman ER, Carey JC, Battaglia A, López‐Granados E, Douglas D, Lapunzina P. International meeting on Wolf‐Hirschhorn syndrome: Update on the nosology and new insights on the pathogenic mechanisms for seizures and growth delay. Am J Med Genet A 2019; 182:257-267. [DOI: 10.1002/ajmg.a.61406] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 10/23/2019] [Indexed: 01/17/2023]
Affiliation(s)
- Julián Nevado
- Medical and Molecular Genetics Institute (INGEMM) La Paz University Hospital, IdiPAZ Madrid Spain
- Basic Research Center in the Rare Diseases Network (CIBERER) Madrid Spain
| | - Karen S. Ho
- Lineagen, Inc. Salt Lake City Utah
- University of Utah School of Medicine Utah
- Hopeful Science, Inc. Salt Lake City Utah
| | - Marcella Zollino
- Institute of Genomic Medicine Catholic University, A. Gemelli Foundation Rome Italy
| | - Raquel Blanco
- Hospital Universitario Central de Asturias Oviedo Spain
| | - César Cobaleda
- Centro de Biología Molecular “Severo Ochoa,” CSIC/UAM Madrid Spain
| | | | | | - Sarah Berrocoso
- Neuro‐e‐Motion Research Team—University of Deusto Bilbao Spain
| | - Jacobo Limeres
- Facultad de Medicina y Odontología Universidad de Santiago de Compostela Santiago Galicia Spain
| | - Pilar Barrúz
- Medical and Molecular Genetics Institute (INGEMM) La Paz University Hospital, IdiPAZ Madrid Spain
| | - Candela Serrano‐Martín
- Facultad de Medicina y Odontología Universidad de Santiago de Compostela Santiago Galicia Spain
| | - Concetta Cafiero
- Institute of Genomic Medicine Catholic University, A. Gemelli Foundation Rome Italy
| | | | - Giuseppe Marangi
- Institute of Genomic Medicine Catholic University, A. Gemelli Foundation Rome Italy
| | | | | | | | | | | | | | | | | | - Cindy Weng
- University of Utah School of Medicine Utah
| | | | | | | | | | - Agatino Battaglia
- Department of Developmental Neuroscience IRCCS Stella Maris Foundation Pisa Italy
| | | | - Damien Douglas
- Wolf‐Hirschhorn Syndrome Trust of the UK and Ireland, Dublin UK
| | - Pablo Lapunzina
- Medical and Molecular Genetics Institute (INGEMM) La Paz University Hospital, IdiPAZ Madrid Spain
- Basic Research Center in the Rare Diseases Network (CIBERER) Madrid Spain
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8
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LETM1: Essential for Mitochondrial Biology and Cation Homeostasis? Trends Biochem Sci 2019; 44:648-658. [DOI: 10.1016/j.tibs.2019.04.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2018] [Revised: 02/28/2019] [Accepted: 04/03/2019] [Indexed: 12/28/2022]
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Durigon R, Mitchell AL, Jones AW, Manole A, Mennuni M, Hirst EM, Houlden H, Maragni G, Lattante S, Doronzio PN, Dalla Rosa I, Zollino M, Holt IJ, Spinazzola A. LETM1 couples mitochondrial DNA metabolism and nutrient preference. EMBO Mol Med 2019; 10:emmm.201708550. [PMID: 30012579 PMCID: PMC6127893 DOI: 10.15252/emmm.201708550] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The diverse clinical phenotypes of Wolf–Hirschhorn syndrome (WHS) are the result of haploinsufficiency of several genes, one of which, LETM1, encodes a protein of the mitochondrial inner membrane of uncertain function. Here, we show that LETM1 is associated with mitochondrial ribosomes, is required for mitochondrial DNA distribution and expression, and regulates the activity of an ancillary metabolic enzyme, pyruvate dehydrogenase. LETM1 deficiency in WHS alters mitochondrial morphology and DNA organization, as does substituting ketone bodies for glucose in control cells. While this change in nutrient availability leads to the death of fibroblasts with normal amounts of LETM1, WHS‐derived fibroblasts survive on ketone bodies, which can be attributed to their reduced dependence on glucose oxidation. Thus, remodeling of mitochondrial nucleoprotein complexes results from the inability of mitochondria to use specific substrates for energy production and is indicative of mitochondrial dysfunction. However, the dysfunction could be mitigated by a modified diet—for WHS, one high in lipids and low in carbohydrates.
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Affiliation(s)
- Romina Durigon
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Alice L Mitchell
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Aleck We Jones
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | - Andreea Manole
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Mara Mennuni
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | | | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | | | - Serena Lattante
- Institute of Genomic Medicine, Catholic University, Rome, Italy
| | | | - Ilaria Dalla Rosa
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK
| | | | - Ian J Holt
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK.,Biodonostia Health Research Institute, San Sebastián, Spain.,IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
| | - Antonella Spinazzola
- Department of Clinical and Movement Neurosciences, UCL Institute of Neurology, London, UK .,MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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10
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Catania A, Legati A, Peverelli L, Nanetti L, Marchet S, Zanetti N, Lamperti C, Ghezzi D. Homozygous variant in OTX2 and possible genetic modifiers identified in a patient with combined pituitary hormone deficiency, ocular involvement, myopathy, ataxia, and mitochondrial impairment. Am J Med Genet A 2019; 179:827-831. [PMID: 30773800 DOI: 10.1002/ajmg.a.61092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 01/21/2019] [Accepted: 01/22/2019] [Indexed: 12/22/2022]
Abstract
Here we report on a singleton patient affected by a complicated congenital syndrome characterized by growth delay, retinal dystrophy, sensorineural deafness, myopathy, ataxia, combined pituitary hormone deficiency, associated with mitochondrial impairment. Targeted clinical exome sequencing led to the identification of a homozygous missense variant in OTX2. Since only dominant mutations within OTX2 have been associated with cases of syndromic microphthalmia, retinal dystrophy with or without pituitary dysfunctions, this represents the first report of an OTX2 recessive mutation. Part of the phenotype, including ataxia, myopathy and multiple mitochondrial respiratory chain defects, seemed not related to OTX2. Further analysis of next generation sequencing (NGS) data revealed additional candidate variants: a homozygous variant in LETM1, and heterozygous rare variants in AFG3L2 and POLG. All three genes encode mitochondrial proteins and the last two are known to be associated with ataxia, a neurological sign present also in the father of the proband. With our study, we aim to encourage the integration of NGS data with a detailed analysis of clinical description and family history in order to unravel composite genotypes sometimes associated with complicated phenotypes.
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Affiliation(s)
- Alessia Catania
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Andrea Legati
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Lorenzo Peverelli
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Neuromuscular and Rare Diseases Unit, Department of Neuroscience, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Lorenzo Nanetti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Silvia Marchet
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Nadia Zanetti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Costanza Lamperti
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Daniele Ghezzi
- Unit of Medical Genetics and Neurogenetics, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.,Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
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11
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Corrêa T, Mergener R, Leite JCL, Galera MF, Moreira LMDA, Vargas JE, Riegel M. Cytogenomic Integrative Network Analysis of the Critical Region Associated with Wolf-Hirschhorn Syndrome. BIOMED RESEARCH INTERNATIONAL 2018; 2018:5436187. [PMID: 29721507 PMCID: PMC5867687 DOI: 10.1155/2018/5436187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/01/2018] [Indexed: 12/19/2022]
Abstract
Deletions in the 4p16.3 region are associated with Wolf-Hirschhorn syndrome (WHS), a contiguous gene deletion syndrome involving variable size deletions. In this study, we perform a cytogenomic integrative analysis combining classical cytogenetic methods, fluorescence in situ hybridization (FISH), chromosomal microarray analysis (CMA), and systems biology strategies, to establish the cytogenomic profile involving the 4p16.3 critical region and suggest WHS-related intracellular cell signaling cascades. The cytogenetic and clinical patient profiles were evaluated. We characterized 12 terminal deletions, one interstitial deletion, two ring chromosomes, and one classical translocation 4;8. CMA allowed delineation of the deletions, which ranged from 3.7 to 25.6 Mb with breakpoints from 4p16.3 to 4p15.33. Furthermore, the smallest region of overlapping (SRO) encompassed seven genes in a terminal region of 330 kb in the 4p16.3 region, suggesting a region of susceptibility to convulsions and microcephaly. Therefore, molecular interaction networks and topological analysis were performed to understand these WHS-related symptoms. Our results suggest that specific cell signaling pathways including dopamine receptor, NAD+ nucleosidase activity, and fibroblast growth factor-activated receptor activity are associated with the diverse pathological WHS phenotypes and their symptoms. Additionally, we identified 29 hub-bottlenecks (H-B) nodes with a major role in WHS.
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Affiliation(s)
- Thiago Corrêa
- Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), 91501-970 Porto Alegre, RS, Brazil
| | - Rafaella Mergener
- Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), 91501-970 Porto Alegre, RS, Brazil
| | - Júlio César Loguercio Leite
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-903 Porto Alegre, RS, Brazil
| | - Marcial Francis Galera
- Department of Pediatrics, Universidade Federal do Mato Grosso (UFMT), 78600-000 Cuiabá, MT, Brazil
| | - Lilia Maria de Azevedo Moreira
- Post-Graduate Program in Genetics and Biodiversity, Universidade Federal da Bahia, Campus Ondina, 40170-290 Salvador, BA, Brazil
| | - José Eduardo Vargas
- Institute of Biological Sciences, Universidade de Passo Fundo, Passo Fundo, RS, Brazil
| | - Mariluce Riegel
- Post-Graduate Program in Genetics and Molecular Biology, Universidade Federal do Rio Grande do Sul (UFRGS), 91501-970 Porto Alegre, RS, Brazil
- Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, 90035-903 Porto Alegre, RS, Brazil
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12
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Austin S, Tavakoli M, Pfeiffer C, Seifert J, Mattarei A, De Stefani D, Zoratti M, Nowikovsky K. LETM1-Mediated K + and Na + Homeostasis Regulates Mitochondrial Ca 2+ Efflux. Front Physiol 2017; 8:839. [PMID: 29204122 PMCID: PMC5698270 DOI: 10.3389/fphys.2017.00839] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 10/09/2017] [Indexed: 12/13/2022] Open
Abstract
Ca2+ transport across the inner membrane of mitochondria (IMM) is of major importance for their functions in bioenergetics, cell death and signaling. It is therefore tightly regulated. It has been recently proposed that LETM1—an IMM protein with a crucial role in mitochondrial K+/H+ exchange and volume homeostasis—also acts as a Ca2+/H+ exchanger. Here we show for the first time that lowering LETM1 gene expression by shRNA hampers mitochondrial K+/H+ and Na+/H+ exchange. Decreased exchange activity resulted in matrix K+ accumulation in these mitochondria. Furthermore, LETM1 depletion selectively decreased Na+/Ca2+ exchange mediated by NCLX, as observed in the presence of ruthenium red, a blocker of the Mitochondrial Ca2+ Uniporter (MCU). These data confirm a key role of LETM1 in monovalent cation homeostasis, and suggest that the effects of its modulation on mitochondrial transmembrane Ca2+ fluxes may reflect those on Na+/H+ exchange activity.
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Affiliation(s)
- Shane Austin
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Mojtaba Tavakoli
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Christina Pfeiffer
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Julia Seifert
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Andrea Mattarei
- Department of Chemical Sciences, Università di Padova, Padova, Italy
| | - Diego De Stefani
- Department of Biomedical Sciences, Università di Padova, Padova, Italy
| | - Mario Zoratti
- Department of Biomedical Sciences, Università di Padova, Padova, Italy.,Institute of Neuroscience (CNR), Padova, Italy
| | - Karin Nowikovsky
- Department of Internal Medicine I and Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
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13
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Huang B, Zhang J, Zhang X, Huang C, Hu G, Li S, Xie T, Liu M, Xu Y. Suppression of LETM1 by siRNA inhibits cell proliferation and invasion of bladder cancer cells. Oncol Rep 2017; 38:2935-2940. [PMID: 29048663 DOI: 10.3892/or.2017.5959] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 08/04/2017] [Indexed: 12/31/2022] Open
Abstract
The leucine zipper-EF-hand containing transmembrane protein 1 (LETM1) is highly expressed in many human malignancies and is correlated with poor prognosis. However, the function of LETM1 in bladder cancer still remains unknown. In the present study, we analyzed the expression levels of LETM1 in bladder cancer tissues and non-cancerous tissues as well as in four bladder cancer cell lines (T24, EJ, 5637 and J82) and a human bladder epithelial immortalized cell line SV-HUC-1. Small interfering RNA (siRNA) was employed to knockdown the expression of LETM1 in the T24 cells. The proliferation of T24 cells was significantly repressed as evaluated by CCK-8 assays. Transwell migration and invasion assays indicated that knockdown of LETM1 suppressed cell migration and invasion significantly. Flow cytometric analysis revealed that cells had accumulated at the S-phase when the expression of LETM1 was suppressed. Moreover, we found that several oncogenic proteins in the Wnt/β-catenin signaling pathway, namely β-catenin, cyclin D1 and c-Myc were significantly decreased by the LETM1 siRNA. Collectively, these results revealed that the knockdown of LETM1 exhibited tumor suppressive effects, possibly by controlling the downstream Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Bisheng Huang
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Jingwei Zhang
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Xiaolu Zhang
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Chi Huang
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Guanghui Hu
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Saiyang Li
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Tiancheng Xie
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Mengnan Liu
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
| | - Yunfei Xu
- Department of Urology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, P.R. China
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14
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Ruggiero A, Aloni E, Korkotian E, Zaltsman Y, Oni-Biton E, Kuperman Y, Tsoory M, Shachnai L, Levin-Zaidman S, Brenner O, Segal M, Gross A. Loss of forebrain MTCH2 decreases mitochondria motility and calcium handling and impairs hippocampal-dependent cognitive functions. Sci Rep 2017; 7:44401. [PMID: 28276496 PMCID: PMC5343590 DOI: 10.1038/srep44401] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 02/07/2017] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial Carrier Homolog 2 (MTCH2) is a novel regulator of mitochondria metabolism, which was recently associated with Alzheimer’s disease. Here we demonstrate that deletion of forebrain MTCH2 increases mitochondria and whole-body energy metabolism, increases locomotor activity, but impairs motor coordination and balance. Importantly, mice deficient in forebrain MTCH2 display a deficit in hippocampus-dependent cognitive functions, including spatial memory, long term potentiation (LTP) and rates of spontaneous excitatory synaptic currents. Moreover, MTCH2-deficient hippocampal neurons display a deficit in mitochondria motility and calcium handling. Thus, MTCH2 is a critical player in neuronal cell biology, controlling mitochondria metabolism, motility and calcium buffering to regulate hippocampal-dependent cognitive functions.
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Affiliation(s)
- Antonella Ruggiero
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Etay Aloni
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eduard Korkotian
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yehudit Zaltsman
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Efrat Oni-Biton
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yael Kuperman
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Tsoory
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Liat Shachnai
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Smadar Levin-Zaidman
- Department of Chemical research Support, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ori Brenner
- Department of Veterinary Resources, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Menahem Segal
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Atan Gross
- Department of Biological Regulation, Weizmann Institute of Science, Rehovot 7610001, Israel
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15
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Wit JM, Oostdijk W, Losekoot M, van Duyvenvoorde HA, Ruivenkamp CAL, Kant SG. MECHANISMS IN ENDOCRINOLOGY: Novel genetic causes of short stature. Eur J Endocrinol 2016; 174:R145-73. [PMID: 26578640 DOI: 10.1530/eje-15-0937] [Citation(s) in RCA: 111] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 11/16/2015] [Indexed: 12/17/2022]
Abstract
The fast technological development, particularly single nucleotide polymorphism array, array-comparative genomic hybridization, and whole exome sequencing, has led to the discovery of many novel genetic causes of growth failure. In this review we discuss a selection of these, according to a diagnostic classification centred on the epiphyseal growth plate. We successively discuss disorders in hormone signalling, paracrine factors, matrix molecules, intracellular pathways, and fundamental cellular processes, followed by chromosomal aberrations including copy number variants (CNVs) and imprinting disorders associated with short stature. Many novel causes of GH deficiency (GHD) as part of combined pituitary hormone deficiency have been uncovered. The most frequent genetic causes of isolated GHD are GH1 and GHRHR defects, but several novel causes have recently been found, such as GHSR, RNPC3, and IFT172 mutations. Besides well-defined causes of GH insensitivity (GHR, STAT5B, IGFALS, IGF1 defects), disorders of NFκB signalling, STAT3 and IGF2 have recently been discovered. Heterozygous IGF1R defects are a relatively frequent cause of prenatal and postnatal growth retardation. TRHA mutations cause a syndromic form of short stature with elevated T3/T4 ratio. Disorders of signalling of various paracrine factors (FGFs, BMPs, WNTs, PTHrP/IHH, and CNP/NPR2) or genetic defects affecting cartilage extracellular matrix usually cause disproportionate short stature. Heterozygous NPR2 or SHOX defects may be found in ∼3% of short children, and also rasopathies (e.g., Noonan syndrome) can be found in children without clear syndromic appearance. Numerous other syndromes associated with short stature are caused by genetic defects in fundamental cellular processes, chromosomal abnormalities, CNVs, and imprinting disorders.
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Affiliation(s)
- Jan M Wit
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Wilma Oostdijk
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Monique Losekoot
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Hermine A van Duyvenvoorde
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Claudia A L Ruivenkamp
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
| | - Sarina G Kant
- Departments of PaediatricsClinical GeneticsLeiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands
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16
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Ho KS, South ST, Lortz A, Hensel CH, Sdano MR, Vanzo RJ, Martin MM, Peiffer A, Lambert CG, Calhoun A, Carey JC, Battaglia A. Chromosomal microarray testing identifies a 4p terminal region associated with seizures in Wolf-Hirschhorn syndrome. J Med Genet 2016; 53:256-63. [PMID: 26747863 PMCID: PMC4819617 DOI: 10.1136/jmedgenet-2015-103626] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Accepted: 11/25/2015] [Indexed: 11/18/2022]
Abstract
Background Wolf–Hirschhorn syndrome (WHS) is a contiguous gene deletion syndrome involving variable size deletions of the 4p16.3 region. Seizures are frequently, but not always, associated with WHS. We hypothesised that the size and location of the deleted region may correlate with seizure presentation. Methods Using chromosomal microarray analysis, we finely mapped the breakpoints of copy number variants (CNVs) in 48 individuals with WHS. Seizure phenotype data were collected through parent-reported answers to a comprehensive questionnaire and supplemented with available medical records. Results We observed a significant correlation between the presence of an interstitial 4p deletion and lack of a seizure phenotype (Fisher's exact test p=3.59e-6). In our cohort, there were five individuals with interstitial deletions with a distal breakpoint at least 751 kbp proximal to the 4p terminus. Four of these individuals have never had an observable seizure, and the fifth individual had a single febrile seizure at the age of 1.5 years. All other individuals in our cohort whose deletions encompass the terminal 751 kbp region report having seizures typical of WHS. Additional examples from the literature corroborate these observations and further refine the candidate seizure susceptibility region to a region 197 kbp in size, starting 368 kbp from the terminus of chromosome 4. Conclusions We identify a small terminal region of chromosome 4p that represents a seizure susceptibility region. Deletion of this region in the context of WHS is sufficient for seizure occurrence.
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Affiliation(s)
- Karen S Ho
- Lineagen, Inc., Salt Lake City, Utah, USA
| | - Sarah T South
- ARUP Laboratories, Salt Lake City, Utah, USA Department of Pathology, University of Utah, Salt Lake City, Utah, USA
| | | | | | | | | | | | - Andreas Peiffer
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Christophe G Lambert
- Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, USA
| | - Amy Calhoun
- Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota, USA
| | - John C Carey
- Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA
| | - Agatino Battaglia
- Stella Maris Clinical Research Institute for Child and Adolescent Neuropsychiatry, Pisa, Italy
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17
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Li N, Zheng Y, Xuan C, Lin Z, Piao L, Liu S. LETM1 overexpression is correlated with the clinical features and survival outcome of breast cancer. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:12893-12900. [PMID: 26722481 PMCID: PMC4680426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 09/28/2015] [Indexed: 06/05/2023]
Abstract
BACKGROUND Leucine zipper/EF hand-containing transmembrane-1 (LETM1) is a mitochondrial inner membrane protein that was first identified in Wolf-Hirschhorn syndrome. However, high-level expression of LETM1 has been correlated with multiple human malignancies, suggesting roles in carcinogenesis and tumor progression. This study is aimed to explore the clinicopathological characteristics and prognostic value of LETM1 overexpression in breast cancer. METHODS Immunohistochemical (IHC) staining, and immunofluorescence (IF) were performed to examine LETM1 expression in breast cancer cell line/tissues compared with adjacent normal tissues. Statistical analysis was applied to evaluate the correlation between LETM1 overexpression and the clinicopathological features of breast cancer. Survival rates were calculated using the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was analyzed using the Cox proportional hazard models. RESULTS LETM1 protein showed cytoplasmic staining pattern in breast cancer. The strongly positive rate of LETM1 protein was 61.6% (98/159) in breast cancer, which was significantly higher than in DCIS (29.7%, 11/37), hyperplasia (16.7%, 3/18) and adjacent normal breast tissues (15.9%, 7/44). High-level expression of LETM1 protein was correlated with lymph node metastasis, poor differentiation, late clinical stage, disease-free survival (DFS) and overall survival (OS) rates in breast cancer. Moreover, multivariate analysis suggested that LETM1 emerged as a significant independent prognostic factor along with clinical stage of patients with breast cancer. CONCLUSIONS LETM1 plays an important role in the progression of breast cancer. High level expression of LETM1 is an independent poor prognostic factor of breast cancer.
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MESH Headings
- Adult
- Aged
- Biomarkers, Tumor/analysis
- Breast Neoplasms/metabolism
- Breast Neoplasms/mortality
- Breast Neoplasms/pathology
- Calcium-Binding Proteins/analysis
- Calcium-Binding Proteins/biosynthesis
- Carcinoma, Ductal, Breast/metabolism
- Carcinoma, Ductal, Breast/mortality
- Carcinoma, Ductal, Breast/pathology
- Carcinoma, Intraductal, Noninfiltrating/metabolism
- Carcinoma, Intraductal, Noninfiltrating/mortality
- Carcinoma, Intraductal, Noninfiltrating/pathology
- Disease Progression
- Disease-Free Survival
- Female
- Fluorescent Antibody Technique
- Humans
- Kaplan-Meier Estimate
- Membrane Proteins/analysis
- Membrane Proteins/biosynthesis
- Middle Aged
- Prognosis
- Proportional Hazards Models
- Up-Regulation
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Affiliation(s)
- Nan Li
- Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian UniversityYanji 133002, Jilin, China
- Department of Pathology & Cancer Research Center, Yanbian University Medical CollegeYanji 133002, Jilin, China
| | - Yahui Zheng
- Department of Pathology & Cancer Research Center, Yanbian University Medical CollegeYanji 133002, Jilin, China
| | - Chouhui Xuan
- Department of Pathology & Cancer Research Center, Yanbian University Medical CollegeYanji 133002, Jilin, China
| | - Zhenhua Lin
- Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian UniversityYanji 133002, Jilin, China
- Department of Pathology & Cancer Research Center, Yanbian University Medical CollegeYanji 133002, Jilin, China
| | - Longzhen Piao
- Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian UniversityYanji 133002, Jilin, China
- Department of Oncology, Yanbian University HospitalYanji 133002, Jilin, China
| | - Shuangping Liu
- Key Laboratory Nature Resources of Changbai Mountain & Functional Molecules, Ministry Education, Yanbian UniversityYanji 133002, Jilin, China
- Department of Pathology & Cancer Research Center, Yanbian University Medical CollegeYanji 133002, Jilin, China
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18
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Lee J, Wong SA, Li BUK, Boles RG. NextGen nuclear DNA sequencing in cyclic vomiting syndrome reveals a significant association with the stress-induced calcium channel (RYR2). Neurogastroenterol Motil 2015; 27:990-6. [PMID: 25925909 DOI: 10.1111/nmo.12575] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/30/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND Cyclic vomiting syndrome (CVS) is a common, frequently disabling, 'functional' condition characterized by recurring, stereotypical attacks of intense nausea, vomiting, and lethargy, with the essential absence of these symptoms between episodes. Although the pathogenesis of CVS is yet unexplained, evidence has accumulated which suggest pathogenic roles for stress-related, autonomic, neuroendocrine, and mitochondrial factors. The objective of this pilot study was to elucidate mechanism(s) by identifying genes involved in the presumed multifactorial pathogenesis of CVS. METHODS In this pilot study, DNA from 75 unrelated CVS cases and 60 healthy controls were assayed by Courtagen Life Science's next-generation sequencing platform (nucSEEK(™) ), including over 1100 nuclear-encoded genes involved with mitochondria, metabolism, or ion channels. Significant sequence variants were defined as evolutionary conservation at least to Xenopus (frog) per the UCSC Genome Browser. KEY RESULTS The RYR2 gene, encoding a stress-induced calcium channel present in many neurons, was the only gene demonstrating a statistically significant difference in the proportion of conserved sequence variants among the groups (18/75 CVS, 24%, vs 3/60 controls, 5%; p = 0.0018, OR = 6.0, 95% CI = 1.7-22). CONCLUSIONS & INFERENCES We propose a mechanism in which RYR2 sequence variants result in aberrant stress-induced calcium release into the mitochondria of autonomic neurons, resulting in an increased risk to develop autonomic/functional disease such as CVS, and related conditions such as migraine and gut dysmotility. This model incorporates the existing hypotheses regarding CVS pathogenesis into a cohesive mechanism, and might have treatment implications.
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Affiliation(s)
- J Lee
- Courtagen Life Sciences Inc., Woburn, MA, USA
| | - S A Wong
- Courtagen Life Sciences Inc., Woburn, MA, USA
| | - B U K Li
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI, USA
| | - R G Boles
- Courtagen Life Sciences Inc., Woburn, MA, USA.,Division of Medical Genetics, Children's Hospital Los Angeles, Los Angeles, CA, USA.,Department of Pediatrics, Keck School of Medicine at USC, Los Angeles, CA, USA
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19
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Wang CA, Liu Q, Chen Y, Liu S, Xu J, Cui X, Zhang Y, Piao L. Clinical implication of leucine zipper/EF hand-containing transmembrane-1 overexpression in the prognosis of triple-negative breast cancer. Exp Mol Pathol 2015; 98:254-9. [DOI: 10.1016/j.yexmp.2014.12.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 12/26/2014] [Indexed: 01/18/2023]
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20
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Hepatic hepcidin protects against polymicrobial sepsis in mice by regulating host iron status. Anesthesiology 2015; 122:374-86. [PMID: 25264597 DOI: 10.1097/aln.0000000000000466] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Hepcidin is a master regulator of iron metabolism primarily produced by the liver. Markedly increased hepcidin levels have been observed in septic individuals, while decreased hepatic hepcidin expression has been demonstrated in liver diseases that tend to develop into sepsis. However, the role of liver hepcidin in sepsis remains unknown. METHODS Mouse hepatic hepcidin expression was silenced using adenovirus-mediated hepcidin-specific short hairpin RNA injected via the tail vein. Sepsis was induced by cecal ligation and puncture, and the outcome (n = 23 for hepcidin knockdown mice, n = 15 for controls) and pathogenic changes (n = 5) related to sepsis were evaluated. The impact of alteration of iron status on the survival rate of hepatic hepcidin knockdown mice (n = 18 to 19) was also investigated. RESULTS Disruption of liver hepcidin expression increased serum iron level (537.8 ± 28.1 μg/dl [mean ± SD] vs. 235.9 ± 62.2 μg/dl; P < 0.05) and reduced iron content in the spleen macrophages at the steady state. Hepatic hepcidin knockdown mice not only showed increased 7-day mortality (73.9% vs. 46.7%; P < 0.05), but also had exacerbated organ damage and oxidative stress, as well as compromised host inflammatory responses and bacterial clearance at 24 h after polymicrobial sepsis. Treating the hepatic hepcidin knockdown mice with low-iron diet plus iron chelation decreased systemic iron content (serum level: 324.0 ± 67.4 μg/dl vs. 517.4 ± 13.4 μg/dl; P < 0.05) and rescued the mice from lethal sepsis (7-day survival: 36.8% vs. 83.3%; P < 0.01). CONCLUSIONS Hepatic hepcidin plays an important role in sepsis through regulation of iron metabolism. The findings may have potential therapeutic implications for liver diseases in which hepcidin expression is decreased.
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21
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Quan X, Nguyen TT, Choi SK, Xu S, Das R, Cha SK, Kim N, Han J, Wiederkehr A, Wollheim CB, Park KS. Essential role of mitochondrial Ca2+ uniporter in the generation of mitochondrial pH gradient and metabolism-secretion coupling in insulin-releasing cells. J Biol Chem 2014; 290:4086-96. [PMID: 25548283 DOI: 10.1074/jbc.m114.632547] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
In pancreatic β-cells, ATP acts as a signaling molecule initiating plasma membrane electrical activity linked to Ca(2+) influx, which triggers insulin exocytosis. The mitochondrial Ca(2+) uniporter (MCU) mediates Ca(2+) uptake into the organelle, where energy metabolism is further stimulated for sustained second phase insulin secretion. Here, we have studied the contribution of the MCU to the regulation of oxidative phosphorylation and metabolism-secretion coupling in intact and permeabilized clonal β-cells as well as rat pancreatic islets. Knockdown of MCU with siRNA transfection blunted matrix Ca(2+) rises, decreased nutrient-stimulated ATP production as well as insulin secretion. Furthermore, MCU knockdown lowered the expression of respiratory chain complexes, mitochondrial metabolic activity, and oxygen consumption. The pH gradient formed across the inner mitochondrial membrane following nutrient stimulation was markedly lowered in MCU-silenced cells. In contrast, nutrient-induced hyperpolarization of the electrical gradient was not altered. In permeabilized cells, knockdown of MCU ablated matrix acidification in response to extramitochondrial Ca(2+). Suppression of the putative Ca(2+)/H(+) antiporter leucine zipper-EF hand-containing transmembrane protein 1 (LETM1) also abolished Ca(2+)-induced matrix acidification. These results demonstrate that MCU-mediated Ca(2+) uptake is essential to establish a nutrient-induced mitochondrial pH gradient which is critical for sustained ATP synthesis and metabolism-secretion coupling in insulin-releasing cells.
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Affiliation(s)
- Xianglan Quan
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Tuyet Thi Nguyen
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Seong-Kyung Choi
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Shanhua Xu
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Ranjan Das
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Seung-Kuy Cha
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea
| | - Nari Kim
- Department of Physiology, College of Medicine, Inje University, Busan 614-735, Korea
| | - Jin Han
- Department of Physiology, College of Medicine, Inje University, Busan 614-735, Korea
| | | | - Claes B Wollheim
- Department of Cell Physiology and Metabolism, University of Geneva, 1211 Geneva 4, Switzerland
| | - Kyu-Sang Park
- From the Department of Physiology, Yonsei University Wonju College of Medicine, Wonju, Gangwon-Do 220-701, Korea,
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