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Zhang Y, Liu G, Huang L, He X, Su Y, Nie X, Mao Z, Xing X. SUN5 interacts with nuclear membrane LaminB1 and cytoskeletal GTPase Septin12 mediating the sperm head-and-tail junction. Mol Hum Reprod 2024; 30:gaae022. [PMID: 38870534 DOI: 10.1093/molehr/gaae022] [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: 12/11/2023] [Revised: 05/21/2024] [Indexed: 06/15/2024] Open
Abstract
Acephalic spermatozoa syndrome (ASS) is a severe teratospermia with decaudated, decapitated, and malformed sperm, resulting in male infertility. Nuclear envelope protein SUN5 localizes to the junction between the sperm head and tail. Mutations in the SUN5 gene have been identified most frequently (33-47%) in ASS cases, and its molecular mechanism of action is yet to be explored. In the present study, we generated Sun5 knockout mice, which presented the phenotype of ASS. Nuclear membrane protein LaminB1 and cytoskeletal GTPases Septin12 and Septin2 were identified as potential partners for interacting with SUN5 by immunoprecipitation-mass spectrometry in mouse testis. Further studies demonstrated that SUN5 connected the nucleus by interacting with LaminB1 and connected the proximal centriole by interacting with Septin12. The binding between SUN5 and Septin12 promoted their aggregation together in the sperm neck. The disruption of the LaminB1/SUN5/Septin12 complex by Sun5 deficiency caused separation of the Septin12-proximal centriole from the nucleus, leading to the breakage of the head-to-tail junction. Collectively, these data provide new insights into the pathogenesis of ASS caused by SUN5 deficiency.
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Affiliation(s)
- Yunfei Zhang
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Gang Liu
- Institute of Reproduction and Stem Cell Engineering, Central South University, Changsha, China
| | - Lihua Huang
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xiyi He
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yuyan Su
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xinmin Nie
- Department of Laboratory Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Zenghui Mao
- Hunan Provincial Key Laboratory of Regional Hereditary Birth Defects Prevention and Control, Changsha Hospital for Maternal & Child Health Care Affiliated to Hunan Normal University, Changsha, China
| | - Xiaowei Xing
- Center for Experimental Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
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Mohar NP, Cox EM, Adelizzi E, Moore SA, Mathews KD, Darbro BW, Wallrath LL. The Influence of a Genetic Variant in CCDC78 on LMNA-Associated Skeletal Muscle Disease. Int J Mol Sci 2024; 25:4930. [PMID: 38732148 PMCID: PMC11084688 DOI: 10.3390/ijms25094930] [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: 03/13/2024] [Revised: 04/12/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Mutations in the LMNA gene-encoding A-type lamins can cause Limb-Girdle muscular dystrophy Type 1B (LGMD1B). This disease presents with weakness and wasting of the proximal skeletal muscles and has a variable age of onset and disease severity. This variability has been attributed to genetic background differences among individuals; however, such variants have not been well characterized. To identify such variants, we investigated a multigeneration family in which affected individuals are diagnosed with LGMD1B. The primary genetic cause of LGMD1B in this family is a dominant mutation that activates a cryptic splice site, leading to a five-nucleotide deletion in the mature mRNA. This results in a frame shift and a premature stop in translation. Skeletal muscle biopsies from the family members showed dystrophic features of variable severity, with the muscle fibers of some family members possessing cores, regions of sarcomeric disruption, and a paucity of mitochondria, not commonly associated with LGMD1B. Using whole genome sequencing (WGS), we identified 21 DNA sequence variants that segregate with the family members possessing more profound dystrophic features and muscle cores. These include a relatively common variant in coiled-coil domain containing protein 78 (CCDC78). This variant was given priority because another mutation in CCDC78 causes autosomal dominant centronuclear myopathy-4, which causes cores in addition to centrally positioned nuclei. Therefore, we analyzed muscle biopsies from family members and discovered that those with both the LMNA mutation and the CCDC78 variant contain muscle cores that accumulated both CCDC78 and RyR1. Muscle cores containing mislocalized CCDC78 and RyR1 were absent in the less profoundly affected family members possessing only the LMNA mutation. Taken together, our findings suggest that a relatively common variant in CCDC78 can impart profound muscle pathology in combination with a LMNA mutation and accounts for variability in skeletal muscle disease phenotypes.
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Affiliation(s)
- Nathaniel P. Mohar
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA; (N.P.M.); (E.A.)
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Efrem M. Cox
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA (S.A.M.)
- Department of Neurosurgery, UNLV School of Medicine, Las Vegas, NV 89106, USA
| | - Emily Adelizzi
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA; (N.P.M.); (E.A.)
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Steven A. Moore
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA (S.A.M.)
| | - Katherine D. Mathews
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA;
| | - Benjamin W. Darbro
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA; (N.P.M.); (E.A.)
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA;
| | - Lori L. Wallrath
- Interdisciplinary Graduate Program in Genetics, University of Iowa, Iowa City, IA 52242, USA; (N.P.M.); (E.A.)
- Department of Biochemistry and Molecular Biology, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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Jiao S, Li C, Guo F, Zhang J, Zhang H, Cao Z, Wang W, Bu W, Lin M, Lü J, Zhou Z. SUN1/2 controls macrophage polarization via modulating nuclear size and stiffness. Nat Commun 2023; 14:6416. [PMID: 37828059 PMCID: PMC10570371 DOI: 10.1038/s41467-023-42187-5] [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: 09/17/2022] [Accepted: 10/03/2023] [Indexed: 10/14/2023] Open
Abstract
Alteration of the size and stiffness of the nucleus triggered by environmental cues are thought to be important for eukaryotic cell fate and function. However, it remains unclear how context-dependent nuclear remodeling occurs and reprograms gene expression. Here we identify the nuclear envelope proteins SUN1/2 as mechano-regulators of the nucleus during M1 polarization of the macrophage. Specifically, we show that LPS treatment decreases the protein levels of SUN1/2 in a CK2-βTrCP-dependent manner to shrink and soften the nucleus, therefore altering the chromatin accessibility for M1-associated gene expression. Notably, the transmembrane helix of SUN1/2 is solely required and sufficient for the nuclear mechano-remodeling. Consistently, SUN1/2 depletion in macrophages facilitates their phagocytosis, tissue infiltration, and proinflammatory cytokine production, thereby boosting the antitumor immunity in mice. Thus, our study demonstrates that, in response to inflammatory cues, SUN1/2 proteins act as mechano-regulators to remodel the nucleus and chromatin for M1 polarization of the macrophage.
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Affiliation(s)
- Shi Jiao
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.
| | - Chuanchuan Li
- CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China
- Human Oncology and Pathogenesis Program, Memorial Sloan Kettering Cancer Center, 417 E 68th St, New York, NY, 10065, USA
| | - Fenghua Guo
- Department of General Surgery, Hua'shan Hospital, Fudan University Shanghai Medical College, Shanghai, 200040, China
| | - Jinjin Zhang
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201203, China
| | - Hui Zhang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Zhifa Cao
- Department of Stomatology, Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200072, China
| | - Wenjia Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China
| | - Wenbo Bu
- Department of Materials Science and State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai, 200433, China
| | - Mobin Lin
- Department of General Surgery, Yangpu Hospital, Tongji University School of Medicine, Shanghai, 200090, China.
| | - Junhong Lü
- Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201203, China.
- College of Pharmacy, Binzhou Medical University, Yantai, 264003, China.
| | - Zhaocai Zhou
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, 200438, China.
- Department of Stomatology, Department of Medical Ultrasound, Shanghai Tenth People's Hospital, Department of Biochemistry and Molecular Biology, Tongji University School of Medicine, Shanghai, 200072, China.
- Collaborative Innovation Center for Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, 211166, China.
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Uemura KI, Miyazono Y, Hiroshige T, Ohta K, Ueda K, Nishihara K, Nakiri M, Hirashima S, Igawa T, Nakamura KI. Three-Dimensional Ultrastructural and Volume Analysis of the Redundant Nuclear Envelope of Developing and Matured Sperm in Mice. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:832-840. [PMID: 37749734 DOI: 10.1093/micmic/ozad003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/14/2022] [Accepted: 01/02/2023] [Indexed: 09/27/2023]
Abstract
The ultrastructure of the nuclear envelope (NE) and redundant NE (RNE) of the spermatozoon cannot be observed in detail using conventional electron microscopy. Thus, this study aimed to employ transmission electron microscopy (TEM) and focused ion beam/scanning electron microscopy (FIB/SEM) tomography to fill this research gap. Male mice aged 13 weeks were deeply anesthetized, and the testes and vas deferens were extracted and processed for electron microscopy. In round spermatids, the acrosomal vesicle compressed the nucleus, and the acrosomal center was depressed. The nucleoli concentrated on the contralateral side of the acrosome formation site. In mature spermatozoa, the RNE accumulated in the neck with the residual bodies. The NE pores exhibited a hexagonal pattern. The body surface area and volume of the nuclei of spermatids and spermatozoa in each maturation phase were analyzed using FIB/SEM tomography. The body surface area and volume of the nuclei decreased during spermatid maturation into spermatozoa. The RNE converged at the sperm neck and possessed a honeycomb structure. The method used revealed that the nuclei of spermatids gradually condense as they mature into spermatozoa. This method may be used to analyze small tissues, such as RNE, and detect morphological abnormalities in microtissues, such as spermatozoa.
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Affiliation(s)
- Kei-Ichiro Uemura
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Yoshihiro Miyazono
- Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, Japan
| | - Tasuku Hiroshige
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Keisuke Ohta
- Advanced Imaging Research Center, Kurume University School of Medicine, Kurume, Japan
| | - Kosuke Ueda
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Kiyoaki Nishihara
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Makoto Nakiri
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Shingo Hirashima
- Dental and Oral Medical Center, Kurume University School of Medicine, Kurume, Japan
- Division of Microscopic and Development Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
| | - Tsukasa Igawa
- Department of Urology, Kurume University School of Medicine, Kurume, Japan
| | - Kei-Ichiro Nakamura
- Division of Microscopic and Development Anatomy, Department of Anatomy, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan
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Shaw NM, Rios-Monterrosa JL, Fedorchak GR, Ketterer MR, Coombs GS, Lammerding J, Wallrath LL. Effects of mutant lamins on nucleo-cytoskeletal coupling in Drosophila models of LMNA muscular dystrophy. Front Cell Dev Biol 2022; 10:934586. [PMID: 36120560 PMCID: PMC9471154 DOI: 10.3389/fcell.2022.934586] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The nuclei of multinucleated skeletal muscles experience substantial external force during development and muscle contraction. Protection from such forces is partly provided by lamins, intermediate filaments that form a scaffold lining the inner nuclear membrane. Lamins play a myriad of roles, including maintenance of nuclear shape and stability, mediation of nuclear mechanoresponses, and nucleo-cytoskeletal coupling. Herein, we investigate how disease-causing mutant lamins alter myonuclear properties in response to mechanical force. This was accomplished via a novel application of a micropipette harpooning assay applied to larval body wall muscles of Drosophila models of lamin-associated muscular dystrophy. The assay enables the measurement of both nuclear deformability and intracellular force transmission between the cytoskeleton and nuclear interior in intact muscle fibers. Our studies revealed that specific mutant lamins increase nuclear deformability while other mutant lamins cause nucleo-cytoskeletal coupling defects, which were associated with loss of microtubular nuclear caging. We found that microtubule caging of the nucleus depended on Msp300, a KASH domain protein that is a component of the linker of nucleoskeleton and cytoskeleton (LINC) complex. Taken together, these findings identified residues in lamins required for connecting the nucleus to the cytoskeleton and suggest that not all muscle disease-causing mutant lamins produce similar defects in subcellular mechanics.
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Affiliation(s)
- Nicholas M. Shaw
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Jose L. Rios-Monterrosa
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gregory R. Fedorchak
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Margaret R. Ketterer
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gary S. Coombs
- Biology Department, Waldorf University, Forest City, IA, United States
| | - Jan Lammerding
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Lori L. Wallrath
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
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Hinz BE, Walker SG, Xiong A, Gogal RA, Schnieders MJ, Wallrath LL. In Silico and In Vivo Analysis of Amino Acid Substitutions That Cause Laminopathies. Int J Mol Sci 2021; 22:ijms222011226. [PMID: 34681887 PMCID: PMC8536974 DOI: 10.3390/ijms222011226] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 10/07/2021] [Accepted: 10/11/2021] [Indexed: 01/08/2023] Open
Abstract
Mutations in the LMNA gene cause diseases called laminopathies. LMNA encodes lamins A and C, intermediate filaments with multiple roles at the nuclear envelope. LMNA mutations are frequently single base changes that cause diverse disease phenotypes affecting muscles, nerves, and fat. Disease-associated amino acid substitutions were mapped in silico onto three-dimensional structures of lamin A/C, revealing no apparent genotype–phenotype connections. In silico analyses revealed that seven of nine predicted partner protein binding pockets in the Ig-like fold domain correspond to sites of disease-associated amino acid substitutions. Different amino acid substitutions at the same position within lamin A/C cause distinct diseases, raising the question of whether the nature of the amino acid replacement or genetic background differences contribute to disease phenotypes. Substitutions at R249 in the rod domain cause muscular dystrophies with varying severity. To address this variability, we modeled R249Q and R249W in Drosophila Lamin C, an orthologue of LMNA. Larval body wall muscles expressing mutant Lamin C caused abnormal nuclear morphology and premature death. When expressed in indirect flight muscles, R249W caused a greater number of adults with wing posturing defects than R249Q, consistent with observations that R249W and R249Q cause distinct muscular dystrophies, with R249W more severe. In this case, the nature of the amino acid replacement appears to dictate muscle disease severity. Together, our findings illustrate the utility of Drosophila for predicting muscle disease severity and pathogenicity of variants of unknown significance.
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Affiliation(s)
- Benjamin E. Hinz
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Sydney G. Walker
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Austin Xiong
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
| | - Rose A. Gogal
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA;
| | - Michael J. Schnieders
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
- Department of Biomedical Engineering, University of Iowa, Iowa City, IA 52242, USA;
| | - Lori L. Wallrath
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA; (B.E.H.); (S.G.W.); (A.X.); (M.J.S.)
- Correspondence: ; Tel.: +1-319-335-7920
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Yadahalli R, Kheur S, Adwani A, Bhonde R, Raj AT, Patil S. Nuclear Blebbing Frequency in Tobacco-Induced Oral Potentially Malignant Disorders: A Pilot Study. Acta Cytol 2021; 65:403-410. [PMID: 34120116 DOI: 10.1159/000516496] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/10/2021] [Indexed: 12/14/2022]
Abstract
INTRODUCTION Tobacco contains several genotoxic agents including N-nitrosamine which has the potential to cause significant nuclear damage. Nuclear blebbing is a form of protrusion on the nuclear membrane and could potentially be caused by tobacco-induced genotoxicity and is closely associated with malignancy. Thus, the present study aimed to assess if tobacco-associated oral potentially malignant disorders including oral submucous fibrosis (OSF) and oral leukoplakia have a higher nuclear blebbing frequency than patients with normal oral mucosa with no history of tobacco use. METHODS The sample consisted of patients with OSF (n = 30) and oral leukoplakia (n = 10) and normal oral mucosa (n = 10). Exfoliated cells collected from the study groups were smeared on a clean microscopic slide and stained by May-Grunwald-Giemsa stain. A baseline frequency of nuclear blebbing was evaluated using a bright-field microscope with a ×100 objective. The number of nuclear blebbing per 1,000 epithelial cells was recorded and expressed in percentage. ANOVA, the Mann-Whitney U test, and Spearman's correlation were used to analyze the data. RESULTS The mean rank of distribution of nuclear blebbing showed significant difference between all 3 groups, with the highest frequency noted in leukoplakia, followed by oral submucous and normal oral mucosa. Within OSF, the frequency of nuclear blebbing significantly increased from early stage to advanced stage. In OSF, a statistically significant positive linear correlation was noted between duration (in years), frequency (per day) of tobacco use, clinical grading, and nuclear blebbing. DISCUSSION/CONCLUSIONS The frequency of nuclear blebbing was significantly higher in oral potentially malignant disorders than normal mucosa. Nuclear blebbing also exhibited a strong dose- and time-dependent correlation with tobacco usage and clinical staging in OSF. The nuclear blebbing frequency could be a noninvasive, economic tool to assess malignant risk in tobacco-induced oral potentially malignant disorders.
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Affiliation(s)
- Roopa Yadahalli
- Department of Oral Pathology and Microbiology, Dr. D.Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - Supriya Kheur
- Department of Oral Pathology and Microbiology, Dr. D.Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - Aanchal Adwani
- Department of Oral Pathology and Microbiology, Dr. D.Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - Ramesh Bhonde
- Department of Oral Pathology and Microbiology, Dr. D.Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Pune, India
| | - A Thirumal Raj
- Department of Oral Pathology and Microbiology, Sri Venkateswara Dental College and Hospital, Chennai, India
| | - Shankargouda Patil
- Division of Oral Pathology College of Dentistry, Department of Maxillofacial Surgery and Diagnostic Sciences, Jazan University, Jazan, Saudi Arabia
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Dobrowolny G, Barbiera A, Sica G, Scicchitano BM. Age-Related Alterations at Neuromuscular Junction: Role of Oxidative Stress and Epigenetic Modifications. Cells 2021; 10:1307. [PMID: 34074012 PMCID: PMC8225025 DOI: 10.3390/cells10061307] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 05/19/2021] [Accepted: 05/22/2021] [Indexed: 12/11/2022] Open
Abstract
With advancing aging, a decline in physical abilities occurs, leading to reduced mobility and loss of independence. Although many factors contribute to the physio-pathological effects of aging, an important event seems to be related to the compromised integrity of the neuromuscular system, which connects the brain and skeletal muscles via motoneurons and the neuromuscular junctions (NMJs). NMJs undergo severe functional, morphological, and molecular alterations during aging and ultimately degenerate. The effect of this decline is an inexorable decrease in skeletal muscle mass and strength, a condition generally known as sarcopenia. Moreover, several studies have highlighted how the age-related alteration of reactive oxygen species (ROS) homeostasis can contribute to changes in the neuromuscular junction morphology and stability, leading to the reduction in fiber number and innervation. Increasing evidence supports the involvement of epigenetic modifications in age-dependent alterations of the NMJ. In particular, DNA methylation, histone modifications, and miRNA-dependent gene expression represent the major epigenetic mechanisms that play a crucial role in NMJ remodeling. It is established that environmental and lifestyle factors, such as physical exercise and nutrition that are susceptible to change during aging, can modulate epigenetic phenomena and attenuate the age-related NMJs changes. This review aims to highlight the recent epigenetic findings related to the NMJ dysregulation during aging and the role of physical activity and nutrition as possible interventions to attenuate or delay the age-related decline in the neuromuscular system.
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Affiliation(s)
- Gabriella Dobrowolny
- Department of Anatomy, Histology, Forensic Medicine and Orthopaedics (DAHFMO)-Unit of Histology and Medical Embryology, Sapienza University of Rome, Laboratory Affiliated to Istituto Pasteur Italia-Fondazione Cenci Bolognetti, 00161 Rome, Italy;
| | - Alessandra Barbiera
- Department of Life Sciences and Public Health, Histology and Embryology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (A.B.); (G.S.)
| | - Gigliola Sica
- Department of Life Sciences and Public Health, Histology and Embryology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (A.B.); (G.S.)
| | - Bianca Maria Scicchitano
- Department of Life Sciences and Public Health, Histology and Embryology Unit, Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy; (A.B.); (G.S.)
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Sharma S, Bhonde R. Genetic and epigenetic stability of stem cells: Epigenetic modifiers modulate the fate of mesenchymal stem cells. Genomics 2020; 112:3615-3623. [DOI: 10.1016/j.ygeno.2020.04.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/08/2020] [Accepted: 04/24/2020] [Indexed: 12/11/2022]
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10
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A Role of Lamin A/C in Preventing Neuromuscular Junction Decline in Mice. J Neurosci 2020; 40:7203-7215. [PMID: 32817327 DOI: 10.1523/jneurosci.0443-20.2020] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/10/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022] Open
Abstract
During aging, skeletal muscles become atrophic and lose contractile force. Aging can also impact the neuromuscular junction (NMJ), a synapse that transmits signals from motoneurons to muscle fibers to control muscle contraction. However, in contrast to muscle aging that has been studied extensively, less is known about the molecular mechanisms of NMJ aging although its structure and function are impaired in aged animals. To this end, we performed RNA sequencing (RNA-seq) analysis to identify genes whose expression in synapse-rich region is altered. Gene ontology (GO) analysis highlighted genes relating to nuclear structure or function. In particular, lamin A/C, an intermediate filament protein critical for the interphase nuclear architecture, was reduced. Remarkably, mutation of lamin A/C in muscles or motoneurons had no effect on NMJ formation in either sex of mice, but the muscle mutation caused progressive denervation, acetylcholine receptor (AChR) cluster fragmentation, and neuromuscular dysfunction. Interestingly, rapsyn, a protein critical to AChR clustering, was reduced in mutant muscle cells; and expressing rapsyn in muscles attenuated NMJ deficits of HSA-Lmna-/- mice. These results reveal a role of lamin A/C in NMJ maintenance and suggest that nuclear dysfunction or deficiency may contribute to NMJ deficits in aged muscles.SIGNIFICANCE STATEMENT This study provides evidence that lamin A/C, a scaffolding component of the nuclear envelope, is critical to maintaining the NMJ in mice. Its muscle-specific mutation led to progressive NMJ degeneration in vivo We showed that the mutation reduced the level of rapsyn, a protein necessary for acetylcholine receptor (AChR) clustering; and expression of rapsyn in muscles attenuated NMJ deficits of HSA-Lmna-/- mice. These results reveal a role of lamin A/C in NMJ maintenance and suggest that nuclear dysfunction or deficiency may contribute to NMJ deficits in aged muscles.
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Unraveling LMNA Mutations in Metabolic Syndrome: Cellular Phenotype and Clinical Pitfalls. Cells 2020; 9:cells9020310. [PMID: 32012908 PMCID: PMC7072715 DOI: 10.3390/cells9020310] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/20/2020] [Accepted: 01/25/2020] [Indexed: 12/13/2022] Open
Abstract
This study details the clinical and cellular phenotypes associated with two missense heterozygous mutations in LMNA, c.1745G>T p.(Arg582Leu), and c.1892G>A p.(Gly631Asp), in two patients with early onset of diabetes mellitus, hypertriglyceridemia and non-alcoholic fatty liver disease. In these two patients, subcutaneous adipose tissue was persistent, at least on the abdomen, and the serum leptin level remained in the normal range. Cellular studies showed elevated nuclear anomalies, an accelerated senescence rate and a decrease of replication capacity in patient cells. In cellular models, the overexpression of mutated prelamin A phenocopied misshapen nuclei, while the partial reduction of lamin A expression in patient cells significantly improved nuclear morphology. Altogether, these results suggest a link between lamin A mutant expression and senescence associated phenotypes. Transcriptome analysis of the whole subcutaneous adipose tissue from the two patients and three controls, paired for age and sex using RNA sequencing, showed the up regulation of genes implicated in immunity and the down regulation of genes involved in development and cell differentiation in patient adipose tissue. Therefore, our results suggest that some mutations in LMNA are associated with severe metabolic phenotypes without subcutaneous lipoatrophy, and are associated with nuclear misshaping.
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Ditaranto R, Boriani G, Biffi M, Lorenzini M, Graziosi M, Ziacchi M, Pasquale F, Vitale G, Berardini A, Rinaldi R, Lattanzi G, Potena L, Martin Suarez S, Bacchi Reggiani ML, Rapezzi C, Biagini E. Differences in cardiac phenotype and natural history of laminopathies with and without neuromuscular onset. Orphanet J Rare Dis 2019; 14:263. [PMID: 31744510 PMCID: PMC6862731 DOI: 10.1186/s13023-019-1245-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 10/29/2019] [Indexed: 01/17/2023] Open
Abstract
Objective To investigate differences in cardiac manifestations of patients affected by laminopathy, according to the presence or absence of neuromuscular involvement at presentation. Methods We prospectively analyzed 40 consecutive patients with a diagnosis of laminopathy followed at a single centre between 1998 and 2017. Additionally, reports of clinical evaluations and tests prior to referral at our centre were retrospectively evaluated. Results Clinical onset was cardiac in 26 cases and neuromuscular in 14. Patients with neuromuscular presentation experienced first symptoms earlier in life (11 vs 39 years; p < 0.0001) and developed atrial fibrillation/flutter (AF) and required pacemaker implantation at a younger age (28 vs 41 years [p = 0.013] and 30 vs 44 years [p = 0.086] respectively), despite a similar overall prevalence of AF (57% vs 65%; p = 0.735) and atrio-ventricular (A-V) block (50% vs 65%; p = 0.500). Those with a neuromuscular presentation developed a cardiomyopathy less frequently (43% vs 73%; p = 0.089) and had a lower rate of sustained ventricular tachyarrhythmias (7% vs 23%; p = 0.387). In patients with neuromuscular onset rhythm disturbances occurred usually before evidence of cardiomyopathy. Despite these differences, the need for heart transplantation and median age at intervention were similar in the two groups (29% vs 23% [p = 0.717] and 43 vs 46 years [p = 0.593] respectively). Conclusions In patients with laminopathy, the type of disease onset was a marker for a different natural history. Specifically, patients with neuromuscular presentation had an earlier cardiac involvement, characterized by a linear and progressive evolution from rhythm disorders (AF and/or A-V block) to cardiomyopathy.
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Affiliation(s)
- Raffaello Ditaranto
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Giuseppe Boriani
- Cardiology Division, Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Policlinico di Modena, Modena, Italy
| | - Mauro Biffi
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Massimiliano Lorenzini
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy.,University College London Institute for Cardiovascular Science and Barts Heart Centre, St. Bartholomew's Hospital, London, UK
| | - Maddalena Graziosi
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Matteo Ziacchi
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Ferdinando Pasquale
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Giovanni Vitale
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Alessandra Berardini
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Rita Rinaldi
- Neurology Unit, Sant'Orsola-Malpighi University Hospital, Bologna, Italy
| | - Giovanna Lattanzi
- Italian National Research Council (CNR), Institute of Molecular Genetics IGM Bologna, Bologna, Italy
| | - Luciano Potena
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Sofia Martin Suarez
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Maria Letizia Bacchi Reggiani
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Claudio Rapezzi
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy
| | - Elena Biagini
- Cardiology Unit, Cardio-Thoracic-Vascular Department, Sant'Orsola-Malpighi Hospital, University of Bologna, Via G. Massarenti 9, 40138, Bologna, Italy.
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Ho R, Hegele RA. Complex effects of laminopathy mutations on nuclear structure and function. Clin Genet 2018; 95:199-209. [DOI: 10.1111/cge.13455] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/26/2018] [Accepted: 09/27/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Rosettia Ho
- Departments of Biochemistry and Medicine, and Robarts Research Institute; Schulich School of Medicine and Dentistry, Western University; London Ontario Canada
| | - Robert A. Hegele
- Departments of Biochemistry and Medicine, and Robarts Research Institute; Schulich School of Medicine and Dentistry, Western University; London Ontario Canada
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Wang X, Zabell A, Koh W, Tang WHW. Lamin A/C Cardiomyopathies: Current Understanding and Novel Treatment Strategies. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2017; 19:21. [PMID: 28299614 DOI: 10.1007/s11936-017-0520-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
OPINION STATEMENT Dilated cardiomyopathy (DCM) is the third leading cause of heart failure in the USA. A major gene associated with DCM with cardiac conduction system disease is lamin A/C (LMNA) gene. Lamins are type V filaments that serve a variety of roles, including nuclear structure support, DNA repair, cell signaling pathway mediation, and chromatin organization. In 1999, LMNA was found responsible for Emery-Dreifuss muscular dystrophy (EDMD) and, since then, has been found in association with a wide spectrum of diseases termed laminopathies, including LMNA cardiomyopathy. Patients with LMNA mutations have a poor prognosis and a higher risk for sudden cardiac death, along with other cardiac effects like dysrhythmias, development of congestive heart failure, and potential need of a pacemaker or ICD. As of now, there is no specific treatment for laminopathies, including LMNA cardiomyopathy, because the mechanism of LMNA mutations in humans is still unclear. This review discusses LMNA mutations and how they relate to DCM, the necessity for further investigation to better understand LMNA mutations, and potential treatment options ranging from clinical and therapeutic to cellular and molecular techniques.
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Affiliation(s)
- Xi Wang
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH, USA
| | - Allyson Zabell
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH, USA
| | - Wonshill Koh
- Children's Hospital of Pittsburgh, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - W H Wilson Tang
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland, OH, USA. .,Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA. .,Center for Clinical Genomics, Cleveland Clinic, Cleveland, OH, USA.
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Kepten E, Miné-Hattab J. [Lamin A: a key protein in chromatin motion]. Med Sci (Paris) 2017; 33:126-130. [PMID: 28240200 DOI: 10.1051/medsci/20173302004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Eldad Kepten
- Institut Curie, PSL Research University, CNRS, Génétique et biologie du développement, UMR 3215, 26, rue d'Ulm, F-75005, Paris, France
| | - Judith Miné-Hattab
- Institut Curie, PSL Research University, CNRS, Dynamique du noyau, UMR 3664, 26, rue d'Ulm, F-75005, Paris, France
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Smith ER, Meng Y, Moore R, Tse JD, Xu AG, Xu XX. Nuclear envelope structural proteins facilitate nuclear shape changes accompanying embryonic differentiation and fidelity of gene expression. BMC Cell Biol 2017; 18:8. [PMID: 28088180 PMCID: PMC5237523 DOI: 10.1186/s12860-017-0125-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 01/07/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Nuclear size and shape are specific to a cell type, function, and location, and can serve as indicators of disease and development. We previously found that lamin A/C and associated nuclear envelope structural proteins were upregulated when murine embryonic stem (ES) cells differentiated to primitive endoderm cells. Here we further investigated the morphological changes of nuclei that accompany this differentiation. RESULTS The nuclei of undifferentiated wild type cells were found shaped as flattened, irregular ovals, whereas nuclei of Gata4-positive endoderm cells were more spherical, less flattened, and with a slightly reduced volume. The morphological change was confirmed in the trophectoderm and primitive endoderm lineages of E4.5 blastocysts, compared to larger and more irregularly shaped of the nuclei of the inner cell mass. We established ES cells genetically null for the nuclear lamina proteins lamin A/C or the inner nuclear envelope protein emerin, or compound mutant for both lamin A/C and emerin. ES cells deficient in lamin A/C differentiated to endoderm but less efficiently, and the nuclei remained flattened and failed to condense. The size and shape of emerin-deficient nuclei also remained uncondensed after treatment with RA. The emerin/lamin A/C double knockout ES cells failed to differentiate to endoderm cells, though the nuclei condensed but retained a generally flattened ellipsoid shape. Additionally, ES cells deficient for lamin A/C and/or emerin had compromised ability to undergo endoderm differentiation, where the differentiating cells often exhibited coexpression of pluripotent and differentiation markers, such as Oct3/4 and Gata4, respectively, indicating an infidelity of gene regulation. CONCLUSIONS The results suggest that changes in nuclear size and shape, which are mediated by nuclear envelope structural proteins lamin A/C and/or emerin, also impact gene regulation and lineage differentiation in early embryos. Nevertheless, mice lacking both lamin A/C and emerin were born at the expected frequency, indicating their embryonic development is completed despite the observed protein deficiency.
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Affiliation(s)
- Elizabeth R Smith
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA.
| | - Yue Meng
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Robert Moore
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Jeffrey D Tse
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Arn G Xu
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Xiang-Xi Xu
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
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Pecorari I, Puzzi L, Sbaizero O. Atomic force microscopy and lamins: A review study towards future, combined investigations. Microsc Res Tech 2016; 80:97-108. [PMID: 27859883 DOI: 10.1002/jemt.22801] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/21/2016] [Accepted: 10/20/2016] [Indexed: 12/13/2022]
Abstract
In the last decades, atomic force microscopy (AFM) underwent a rapid and stunning development, especially for studying mechanical properties of biological samples. The numerous discoveries relying to this approach, have increased the credit of AFM as a versatile tool, and potentially eligible as a diagnostic equipment. Meanwhile, it has become strikingly evident that lamins are involved on the onset and development of certain diseases, including cancer, Hutchinson-Gilford progeria syndrome, cardiovascular pathologies, and muscular dystrophy. A new category of pathologies has been defined, the laminopathies, which are caused by mutations in the gene encoding for A-type lamins. As the majority of medical issues, lamins, and all their related aspects can be considered as a quite complex problem. Indeed, there are many facets to explore, and this definitely requires a multidisciplinary approach. One of the most intriguing aspects concerning lamins is their remarkable contribute to cells mechanics. Over the years, this has led to the speculation of the so-called "structural hypothesis", which attempts to elucidate the etiology and some features of the laminopathies. Among the various techniques tried to figure out the role of lamins in the cells mechanics, the AFM has been already successfully applied, proving its versatility. Therefore, the present work aims both to highlight the qualities of AFM and to review the most relevant knowledge about lamins, in order to promote the study of the latter, taking advantage from the former. Microsc. Res. Tech. 80:97-108, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ilaria Pecorari
- Department of Engineering and Architecture, University of Trieste, Via Valerio 6-34127, Trieste, Italy
| | - Luca Puzzi
- Department of Engineering and Architecture, University of Trieste, Via Valerio 6-34127, Trieste, Italy
| | - Orfeo Sbaizero
- Department of Engineering and Architecture, University of Trieste, Via Valerio 6-34127, Trieste, Italy
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Significance of 1B and 2B domains in modulating elastic properties of lamin A. Sci Rep 2016; 6:27879. [PMID: 27301336 PMCID: PMC4908593 DOI: 10.1038/srep27879] [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: 01/08/2016] [Accepted: 05/23/2016] [Indexed: 12/20/2022] Open
Abstract
Nuclear lamins are type V intermediate filament proteins which form an elastic
meshwork underlying the inner nuclear membrane. Lamins directly contribute to
maintain the nuclear shape and elasticity. More than 400 mutations have been
reported in lamin A that are involved in diseases known as laminopathies. These
mutations are scattered mainly in the lamin rod domain along with some in its
C-terminal domain. The contribution of the rod domain towards the elasticity of
lamin A molecule was hitherto unknown. Here, we have elucidated the significance of
the 1B and 2B domains of the rod in modulating the elastic behavior of lamin A by
single-molecule force spectroscopy. In addition, we have also studied the network
forming capacity of these domains and their corresponding viscoelastic behavior. We
have shown that the 1B domain has the ability to form a lamin-like network and
resists larger deformation. However at the single-molecular level, both the domains
have comparable mechanical properties. The self-assembly of the 1B domain
contributes to the elasticity of the lamin A network.
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19
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Regulation of nuclear shape and size in plants. Curr Opin Cell Biol 2016; 40:114-123. [PMID: 27030912 DOI: 10.1016/j.ceb.2016.03.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/03/2016] [Accepted: 03/09/2016] [Indexed: 11/22/2022]
Abstract
Nuclear shape and size changes have long been used by cytopathologists to diagnose, stage, and prognose cancer. However, the underlying causalities and molecular mechanisms are largely unknown. The current eukaryotic tree of life groups eukaryotes into five supergroups, with all organisms between humans and yeast falling into the supergroup Opisthokonta. The emergence of model organisms with strong molecular genetic methodology in the other supergroups has recently facilitated a broader evolutionary approach to pressing biological questions. Here, we review what is known about the control of nuclear shape and size in the Archaeplastidae, the supergroup containing the higher plants. We discuss common themes as well as differences toward a more generalized model of how eukaryotic organisms regulate nuclear morphology.
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Aljada A, Doria J, Saleh AM, Al-Matar SH, AlGabbani S, Shamsa HB, Al-Bawab A, Ahmed AA. Altered Lamin A/C splice variant expression as a possible diagnostic marker in breast cancer. Cell Oncol (Dordr) 2016; 39:161-74. [PMID: 26732077 DOI: 10.1007/s13402-015-0265-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2015] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Lamin A/C alternative splice variants (Lamin A, Lamin C, Lamin AΔ10 and Lamin AΔ50) have been implicated in cell cycle regulation, DNA replication, transcription regulation, cellular differentiation, apoptosis and aging. In addition, loss of Lamin A/C expression has been observed in several cancers, including breast cancer, and it has been found that Lamin A/C suppression may lead to cancer-like aberrations in nuclear morphology and aneuploidy. Based on these observations, we hypothesized that Lamin A/C transcript variant quantification might be employed for the diagnosis of breast cancer. METHODS Newly designed TaqMan qRT-PCR assays for the analysis of Lamin A/C splice variants were validated and their use as biomarkers for the diagnosis of breast cancer was assessed using 16 normal breast tissues and 128 breast adenocarcinomas. In addition, the expression levels of the Lamin A/C transcript variants were measured in samples derived from seven other types of cancer. RESULTS We found that the expression level of Lamin C was significantly increased in the breast tumors tested, whereas the expression levels of Lamin A and Lamin AΔ50 were significantly decreased. No significant change in Lamin AΔ10 expression was observed. Our data also indicated that the Lamin C : Lamin A mRNA ratio was increased in all clinical stages of breast cancer. Additionally, we observed increased Lamin C : Lamin A mRNA ratios in liver, lung and thyroid carcinomas and in colon, ovary and prostate adenocarcinomas. CONCLUSIONS From our data we conclude that the Lamin C : Lamin A mRNA ratio is increased in breast cancer and that this mRNA ratio may be of diagnostic use in all clinical stages of breast cancer and, possibly, also in liver, lung, thyroid, colon, ovary and prostate cancers.
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Affiliation(s)
- Ahmad Aljada
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia.
- King Abdullah International Medical Research Center (KAIMRC), National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia.
| | - Joseph Doria
- Department of Neurology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Ayman M Saleh
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
- King Abdullah International Medical Research Center (KAIMRC), National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Shahad H Al-Matar
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Sarah AlGabbani
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Heba Bani Shamsa
- King Abdullah International Medical Research Center (KAIMRC), National Guard Health Affairs, Riyadh, Kingdom of Saudi Arabia
| | - Ahmad Al-Bawab
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
| | - Altayeb Abdalla Ahmed
- Department of Basic Medical Sciences, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia
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Vermeij WP, Hoeijmakers JHJ, Pothof J. Genome Integrity in Aging: Human Syndromes, Mouse Models, and Therapeutic Options. Annu Rev Pharmacol Toxicol 2015; 56:427-45. [PMID: 26514200 DOI: 10.1146/annurev-pharmtox-010814-124316] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Human syndromes and mouse mutants that exhibit accelerated but bona fide aging in multiple organs and tissues have been invaluable for the identification of nine denominators of aging: telomere attrition, genome instability, epigenetic alterations, mitochondrial dysfunction, deregulated nutrient sensing, altered intercellular communication, loss of proteostasis, cellular senescence and adult stem cell exhaustion. However, whether and how these instigators of aging interrelate or whether they have one root cause is currently largely unknown. Rare human progeroid syndromes and corresponding mouse mutants with resolved genetic defects highlight the dominant importance of genome maintenance for aging. A second class of aging-related disorders reveals a cross connection with metabolism. As genome maintenance and metabolism are closely interconnected, they may constitute the main underlying biology of aging. This review focuses on the role of genome stability in aging, its crosstalk with metabolism, and options for nutritional and/or pharmaceutical interventions that delay age-related pathology.
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Affiliation(s)
- Wilbert P Vermeij
- Department of Genetics, Erasmus University Medical Center, Postbus 2040, 3000 CA, Rotterdam, The Netherlands; , ,
| | - Jan H J Hoeijmakers
- Department of Genetics, Erasmus University Medical Center, Postbus 2040, 3000 CA, Rotterdam, The Netherlands; , ,
| | - Joris Pothof
- Department of Genetics, Erasmus University Medical Center, Postbus 2040, 3000 CA, Rotterdam, The Netherlands; , ,
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Sharma S, Bhonde R. Mesenchymal stromal cells are genetically stable under a hostile in vivo–like scenario as revealed by in vitro micronucleus test. Cytotherapy 2015; 17:1384-95. [DOI: 10.1016/j.jcyt.2015.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 06/30/2015] [Accepted: 07/05/2015] [Indexed: 02/07/2023]
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Abstract
Recent studies show that nuclear lamins, the type V intermediate filament proteins, are required for proper building of at least some organs. As the major structural components of the nuclear lamina found underneath the inner nuclear membranes, lamins are ubiquitously expressed in all animal cells. How the broadly expressed lamins support the building of specific tissues is not understood. By studying Drosophila testis, we have uncovered a mechanism by which lamin-B functions in the cyst stem cell (CySC) and its differentiated cyst cell, the cell types known to form the niche/microenvironment for the germline stem cells (GSC) and the developing germ line, to ensure testis organogenesis (1). In this extra view, we discuss some remaining questions and the implications of our findings in the understanding of how the ubiquitous nuclear lamina regulates tissue building in a context-dependent manner.
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Affiliation(s)
- Haiyang Chen
- a Department of Embryology; Carnegie Institution for Science; Baltimore, MD USA
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The Cardiomyopathy Lamin A/C D192G Mutation Disrupts Whole-Cell Biomechanics in Cardiomyocytes as Measured by Atomic Force Microscopy Loading-Unloading Curve Analysis. Sci Rep 2015; 5:13388. [PMID: 26323789 PMCID: PMC4555041 DOI: 10.1038/srep13388] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 07/23/2015] [Indexed: 12/30/2022] Open
Abstract
Atomic force microscopy (AFM) cell loading/unloading curves were used to provide comprehensive insights into biomechanical behavior of cardiomyocytes carrying the lamin A/C (LMNA) D192G mutation known to cause defective nuclear wall, myopathy and severe cardiomyopathy. Our results suggested that the LMNA D192G mutation increased maximum nuclear deformation load, nuclear stiffness and fragility as compared to controls. Furthermore, there seems to be a connection between this lamin nuclear mutation and cell adhesion behavior since LMNA D192G cardiomyocytes displayed loss of AFM probe-to-cell membrane adhesion. We believe that this loss of adhesion involves the cytoskeletal architecture since our microscopic analyses highlighted that mutant LMNA may also lead to a morphological alteration in the cytoskeleton. Furthermore, chemical disruption of the actin cytoskeleton by cytochalasin D in control cardiomyocytes mirrored the alterations in the mechanical properties seen in mutant cells, suggesting a defect in the connection between the nucleoskeleton, cytoskeleton and cell adhesion molecules in cells expressing the mutant protein. These data add to our understanding of potential mechanisms responsible for this fatal cardiomyopathy, and show that the biomechanical effects of mutant lamin extend beyond nuclear mechanics to include interference of whole-cell biomechanical properties.
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Wang K, Das A, Xiong ZM, Cao K, Hannenhalli S. Phenotype-Dependent Coexpression Gene Clusters: Application to Normal and Premature Ageing. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2015; 12:30-39. [PMID: 26357076 PMCID: PMC5562542 DOI: 10.1109/tcbb.2014.2359446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Hutchinson Gilford progeria syndrome (HGPS) is a rare genetic disease with symptoms of aging at a very early age. Its molecular basis is not entirely clear, although profound gene expression changes have been reported, and there are some known and other presumed overlaps with normal aging process. Identification of genes with agingor HGPS-associated expression changes is thus an important problem. However, standard regression approaches are currently unsuitable for this task due to limited sample sizes, thus motivating development of alternative approaches. Here, we report a novel iterative multiple regression approach that leverages co-expressed gene clusters to identify gene clusters whose expression co-varies with age and/or HGPS. We have applied our approach to novel RNA-seq profiles in fibroblast cell cultures at three different cellular ages, both from HGPS patients and normal samples. After establishing the robustness of our approach, we perform a comparative investigation of biological processes underlying normal aging and HGPS. Our results recapitulate previously known processes underlying aging as well as suggest numerous unique processes underlying aging and HGPS. The approach could also be useful in detecting phenotype-dependent co-expression gene clusters in other contexts with limited sample sizes.
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Sharma S, Bhonde R. Influence of Nuclear Blebs and Micronuclei Status on the Growth Kinetics of Human Mesenchymal Stem Cells. J Cell Physiol 2014; 230:657-66. [DOI: 10.1002/jcp.24789] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 08/29/2014] [Indexed: 12/13/2022]
Affiliation(s)
- Shikha Sharma
- School of Regenerative Medicine; Manipal University; Bangalore Karnataka India
| | - Ramesh Bhonde
- School of Regenerative Medicine; Manipal University; Bangalore Karnataka India
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Reichert C, Gölz L, Götz W, Wolf M, Deschner J, Jäger A. Dental and craniofacial characteristics in a patient with Hutchinson-Gilford progeria syndrome. J Orofac Orthop 2014; 75:251-63. [PMID: 25001855 DOI: 10.1007/s00056-014-0216-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Accepted: 01/31/2013] [Indexed: 11/28/2022]
Abstract
The Hutchinson-Gilford progeria syndrome (HGPS) is an exceptionally rare medical disorder caused by mutations in the lamin A/C gene. Affected patients display typical features of premature aging. Beside general medical disorders, these patients have several specific features related to the craniofacial phenotype and the oral cavity. In this article, the dental and craniofacial characteristics of a 9-year-old girl with HGPS are presented. It is the first report addressing orthodontic tooth movement and microbiological features in a HGPS patient. We describe and discuss pathologic findings and provide a detailed histology of the teeth which had to be extracted during initial treatment.
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Affiliation(s)
- Christoph Reichert
- Department of Orthodontics, Dental Hospital, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany,
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Datta S, Snow CJ, Paschal BM. A pathway linking oxidative stress and the Ran GTPase system in progeria. Mol Biol Cell 2014; 25:1202-15. [PMID: 24523287 PMCID: PMC3982987 DOI: 10.1091/mbc.e13-07-0430] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Maintaining the Ran GTPase at a proper concentration in the nucleus is important for nucleocytoplasmic transport. Previously we found that nuclear levels of Ran are reduced in cells from patients with Hutchinson-Gilford progeria syndrome (HGPS), a disease caused by constitutive attachment of a mutant form of lamin A (termed progerin) to the nuclear membrane. Here we explore the relationship between progerin, the Ran GTPase, and oxidative stress. Stable attachment of progerin to the nuclear membrane disrupts the Ran gradient and results in cytoplasmic localization of Ubc9, a Ran-dependent import cargo. Ran and Ubc9 disruption can be induced reversibly with H2O2. CHO cells preadapted to oxidative stress resist the effects of progerin on Ran and Ubc9. Given that HGPS-patient fibroblasts display elevated ROS, these data suggest that progerin inhibits nuclear transport via oxidative stress. A drug that inhibits pre-lamin A cleavage mimics the effects of progerin by disrupting the Ran gradient, but the effects on Ran are observed before a substantial ROS increase. Moreover, reducing the nuclear concentration of Ran is sufficient to induce ROS irrespective of progerin. We speculate that oxidative stress caused by progerin may occur upstream or downstream of Ran, depending on the cell type and physiological setting.
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Affiliation(s)
- Sutirtha Datta
- Center for Cell Signaling, Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903
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29
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Malhas AN, Vaux DJ. Nuclear envelope invaginations and cancer. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 773:523-35. [PMID: 24563364 DOI: 10.1007/978-1-4899-8032-8_24] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The nuclear envelope (NE) surrounds the nucleus and separates it from the cytoplasm. The NE is not a passive structural component, but rather contributes to various cellular processes such as genome organization, transcription, signaling, and stress responses. Although the NE is mostly a smooth surface, it also forms invaginations that can reach deep into the nucleoplasm and may even traverse the nucleus completely. Cancer cells are generally characterized by irregularities and invaginations of the NE that are of diagnostic and prognostic significance. In the current chapter, we describe the link between nuclear invaginations and irregularities with cancer and explore possible mechanistic roles they might have in tumorigenesis.
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Affiliation(s)
- Ashraf N Malhas
- Sir William Dunn School of Pathology, South Parks Road, Oxford, OX1 3RE, UK,
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Xiong Z, Lu Y, Xue J, Luo S, Xu X, Zhang L, Peng H, Li W, Chen D, Hu Z, Xia K. Hutchinson-Gilford progeria syndrome accompanied by severe skeletal abnormalities in two Chinese siblings: two case reports. J Med Case Rep 2013; 7:63. [PMID: 23497705 PMCID: PMC3602076 DOI: 10.1186/1752-1947-7-63] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2012] [Accepted: 01/28/2013] [Indexed: 11/10/2022] Open
Abstract
Introduction Hutchinson-Gilford progeria syndrome is a rare pediatric genetic syndrome with an incidence of one per eight million live births. The disorder is characterized by premature aging, generally leading to death due to myocardial infarction or stroke at approximately 13.4 years of age. The genetic diagnosis and special clinical manifestation in two Han Chinese siblings observed at our clinic for genetic counseling are described in this report. We screened the LMNA gene in these two siblings as well as in their unaffected parents. A homozygous mutation R527C was identified in the affected siblings, and both parents were heterozygous for this variant. Case presentation In case 1, the elder 10-year-old female sibling showed the classic physical and radiological changes of Hutchinson-Gilford progeria syndrome in addition to a considerable overlap with the phenotype of mandibuloacral dysplasia. In case 2, the younger male sibling had begun to show some early physical changes at age six months. Conclusion The phenotypic findings in the patients we describe here widen the clinical spectrum of Hutchinson-Gilford progeria syndrome symptoms, providing further recognition of the phenotypic range of LMNA-associated diseases.
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Affiliation(s)
- Zhimin Xiong
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China.
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Abstract
Much of the structural stability of the nucleus comes from meshworks of intermediate filament proteins known as lamins forming the inner layer of the nuclear envelope called the nuclear lamina. These lamin meshworks additionally play a role in gene expression. Abnormalities in nuclear shape are associated with a variety of pathologies, including some forms of cancer and Hutchinson-Gilford Progeria Syndrome, and often include protruding structures termed nuclear blebs. These nuclear blebs are thought to be related to pathological gene expression; however, little is known about how and why blebs form. We have developed a minimal continuum elastic model of a lamin meshwork that we use to investigate which aspects of the meshwork could be responsible for bleb formation. Mammalian lamin meshworks consist of two types of lamin proteins, A type and B type, and it has been reported that nuclear blebs are enriched in A-type lamins. Our model treats each lamin type separately and thus, can assign them different properties. Nuclear blebs have been reported to be located in regions where the fibers in the lamin meshwork have a greater separation, and we find that this greater separation of fibers is an essential characteristic for generating nuclear blebs. The model produces structures with comparable morphologies and distributions of lamin types as real pathological nuclei. Thus, preventing this opening of the meshwork could be a route to prevent bleb formation, which could be used as a potential therapy for the pathologies associated with nuclear blebs.
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32
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Zhang H, Kieckhaefer JE, Cao K. Mouse models of laminopathies. Aging Cell 2013; 12:2-10. [PMID: 23095062 DOI: 10.1111/acel.12021] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2012] [Indexed: 01/02/2023] Open
Abstract
The A- and B-type lamins are nuclear intermediate filament proteins in eukaryotic cells with a broad range of functions, including the organization of nuclear architecture and interaction with proteins in many cellular functions. Over 180 disease-causing mutations, termed 'laminopathies,' have been mapped throughout LMNA, the gene for A-type lamins in humans. Laminopathies can range from muscular dystrophies, cardiomyopathy, to Hutchinson-Gilford progeria syndrome. A number of mouse lines carrying some of the same mutations as those resulting in human diseases have been established. These LMNA-related mouse models have provided valuable insights into the functions of lamin A biogenesis and the roles of individual A-type lamins during tissue development. This review groups these LMNA-related mouse models into three categories: null mutants, point mutants, and progeroid mutants. We compare their phenotypes and discuss their potential implications in laminopathies and aging.
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Affiliation(s)
- Haoyue Zhang
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park; MD 20742; USA
| | - Julia E. Kieckhaefer
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park; MD 20742; USA
| | - Kan Cao
- Department of Cell Biology and Molecular Genetics; University of Maryland; College Park; MD 20742; USA
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Nesbit MA, Hannan FM, Howles SA, Reed AAC, Cranston T, Thakker CE, Gregory L, Rimmer AJ, Rust N, Graham U, Morrison PJ, Hunter SJ, Whyte MP, McVean G, Buck D, Thakker RV. Mutations in AP2S1 cause familial hypocalciuric hypercalcemia type 3. Nat Genet 2013; 45:93-7. [PMID: 23222959 PMCID: PMC3605788 DOI: 10.1038/ng.2492] [Citation(s) in RCA: 165] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 11/09/2012] [Indexed: 11/08/2022]
Abstract
Adaptor protein-2 (AP2), a central component of clathrin-coated vesicles (CCVs), is pivotal in clathrin-mediated endocytosis, which internalizes plasma membrane constituents such as G protein-coupled receptors (GPCRs). AP2, a heterotetramer of α, β, μ and σ subunits, links clathrin to vesicle membranes and binds to tyrosine- and dileucine-based motifs of membrane-associated cargo proteins. Here we show that missense mutations of AP2 σ subunit (AP2S1) affecting Arg15, which forms key contacts with dileucine-based motifs of CCV cargo proteins, result in familial hypocalciuric hypercalcemia type 3 (FHH3), an extracellular calcium homeostasis disorder affecting the parathyroids, kidneys and bone. We found AP2S1 mutations in >20% of cases of FHH without mutations in calcium-sensing GPCR (CASR), which cause FHH1. AP2S1 mutations decreased the sensitivity of CaSR-expressing cells to extracellular calcium and reduced CaSR endocytosis, probably through loss of interaction with a C-terminal CaSR dileucine-based motif, whose disruption also decreased intracellular signaling. Thus, our results identify a new role for AP2 in extracellular calcium homeostasis.
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Affiliation(s)
- M Andrew Nesbit
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
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Wang W, Shi Z, Jiao S, Chen C, Wang H, Liu G, Wang Q, Zhao Y, Greene MI, Zhou Z. Structural insights into SUN-KASH complexes across the nuclear envelope. Cell Res 2012; 22:1440-52. [PMID: 22945352 DOI: 10.1038/cr.2012.126] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Linker of the nucleoskeleton and the cytoskeleton (LINC) complexes are composed of SUN and KASH domain-containing proteins and bridge the inner and outer membranes of the nuclear envelope. LINC complexes play critical roles in nuclear positioning, cell polarization and cellular stiffness. Previously, we reported the homotrimeric structure of human SUN2. We have now determined the crystal structure of the human SUN2-KASH complex. In the complex structure, the SUN domain homotrimer binds to three independent "hook"-like KASH peptides. The overall conformation of the SUN domain in the complex closely resembles the SUN domain in its apo state. A major conformational change involves the AA'-loop of KASH-bound SUN domain, which rearranges to form a mini β-sheet that interacts with the KASH peptide. The PPPT motif of the KASH domain fits tightly into a hydrophobic pocket on the homotrimeric interface of the SUN domain, which we termed the BI-pocket. Moreover, two adjacent protomers of the SUN domain homotrimer sandwich the KASH domain by hydrophobic interaction and hydrogen bonding. Mutations of these binding sites disrupt or reduce the association between the SUN and KASH domains in vitro. In addition, transfection of wild-type, but not mutant, SUN2 promotes cell migration in Ovcar-3 cells. These results provide a structural model of the LINC complex, which is essential for additional study of the physical and functional coupling between the cytoplasm and the nucleoplasm.
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Affiliation(s)
- Wenjia Wang
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
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35
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McGrath J, Robinson M, Binder R. Skin differences based on age and chronicity of ultraviolet exposure: results from a gene expression profiling study. Br J Dermatol 2012; 166 Suppl 2:9-15. [DOI: 10.1111/j.1365-2133.2012.10860.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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36
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Structures of the lamin A/C R335W and E347K mutants: Implications for dilated cardiolaminopathies. Biochem Biophys Res Commun 2012; 418:217-21. [DOI: 10.1016/j.bbrc.2011.12.136] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 12/25/2011] [Indexed: 11/19/2022]
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Abstract
This chapter focuses on the three-dimensional organization of the nucleus in normal, early genomically unstable, and tumor cells. A cause-consequence relationship is discussed between nuclear alterations and the resulting genomic rearrangements. Examples are presented from studies on conditional Myc deregulation, experimental tumorigenesis in mouse plasmacytoma, nuclear remodeling in Hodgkin's lymphoma, and in adult glioblastoma. A model of nuclear remodeling is proposed for cancer progression in multiple myeloma. Current models of nuclear remodeling are described, including our model of altered nuclear architecture and the onset of genomic instability.
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38
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Verhagen AM, de Graaf CA, Baldwin TM, Goradia A, Collinge JE, Kile BT, Metcalf D, Starr R, Hilton DJ. Reduced lymphocyte longevity and homeostatic proliferation in lamin B receptor-deficient mice results in profound and progressive lymphopenia. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2012; 188:122-34. [PMID: 22105998 DOI: 10.4049/jimmunol.1100942] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The lamin B receptor (LBR) is a highly unusual inner nuclear membrane protein with multiple functions. Reduced levels are associated with decreased neutrophil lobularity, whereas complete absence of LBR results in severe skeletal dysplasia and in utero/perinatal lethality. We describe a mouse pedigree, Lym3, with normal bone marrow and thymic development but profound and progressive lymphopenia particularly within the T cell compartment. This defect arises from a point mutation within the Lbr gene with only trace mutant protein detectable in homozygotes, albeit sufficient for normal development. Reduced T cell homeostatic proliferative potential and life span in vivo were found to contribute to lymphopenia. To investigate the role of LBR in gene silencing in hematopoietic cells, we examined gene expression in wild-type and mutant lymph node CD8 T cells and bone marrow neutrophils. Although LBR deficiency had a very mild impact on gene expression overall, for common genes differentially expressed in both LBR-deficient CD8 T cells and neutrophils, gene upregulation prevailed, supporting a role for LBR in their suppression. In summary, this study demonstrates that LBR deficiency affects not only nuclear architecture but also proliferation, cell viability, and gene expression of hematopoietic cells.
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Affiliation(s)
- Anne M Verhagen
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia.
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39
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Shimi T, Butin-Israeli V, Adam SA, Hamanaka RB, Goldman AE, Lucas CA, Shumaker DK, Kosak ST, Chandel NS, Goldman RD. The role of nuclear lamin B1 in cell proliferation and senescence. Genes Dev 2011; 25:2579-93. [PMID: 22155925 DOI: 10.1101/gad.179515.111] [Citation(s) in RCA: 378] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Nuclear lamin B1 (LB1) is a major structural component of the nucleus that appears to be involved in the regulation of many nuclear functions. The results of this study demonstrate that LB1 expression in WI-38 cells decreases during cellular senescence. Premature senescence induced by oncogenic Ras also decreases LB1 expression through a retinoblastoma protein (pRb)-dependent mechanism. Silencing the expression of LB1 slows cell proliferation and induces premature senescence in WI-38 cells. The effects of LB1 silencing on proliferation require the activation of p53, but not pRb. However, the induction of premature senescence requires both p53 and pRb. The proliferation defects induced by silencing LB1 are accompanied by a p53-dependent reduction in mitochondrial reactive oxygen species (ROS), which can be rescued by growth under hypoxic conditions. In contrast to the effects of LB1 silencing, overexpression of LB1 increases the proliferation rate and delays the onset of senescence of WI-38 cells. This overexpression eventually leads to cell cycle arrest at the G1/S boundary. These results demonstrate the importance of LB1 in regulating the proliferation and senescence of human diploid cells through a ROS signaling pathway.
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Affiliation(s)
- Takeshi Shimi
- Department of Cell and Molecular Biology, Division of Pulmonary and Critical Care Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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40
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Meyer AJ, Almendrala DK, Go MM, Krauss SW. Structural protein 4.1R is integrally involved in nuclear envelope protein localization, centrosome-nucleus association and transcriptional signaling. J Cell Sci 2011; 124:1433-44. [PMID: 21486941 DOI: 10.1242/jcs.077883] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The multifunctional structural protein 4.1R is required for assembly and maintenance of functional nuclei but its nuclear roles are unidentified. 4.1R localizes within nuclei, at the nuclear envelope, and in cytoplasm. Here we show that 4.1R, the nuclear envelope protein emerin and the intermediate filament protein lamin A/C co-immunoprecipitate, and that 4.1R-specific depletion in human cells by RNA interference produces nuclear dysmorphology and selective mislocalization of proteins from several nuclear subcompartments. Such 4.1R-deficiency causes emerin to partially redistribute into the cytoplasm, whereas lamin A/C is disorganized at nuclear rims and displaced from nucleoplasmic foci. The nuclear envelope protein MAN1, nuclear pore proteins Tpr and Nup62, and nucleoplasmic proteins NuMA and LAP2α also have aberrant distributions, but lamin B and LAP2β have normal localizations. 4.1R-deficient mouse embryonic fibroblasts show a similar phenotype. We determined the functional effects of 4.1R-deficiency that reflect disruption of the association of 4.1R with emerin and A-type lamin: increased nucleus-centrosome distances, increased β-catenin signaling, and relocalization of β-catenin from the plasma membrane to the nucleus. Furthermore, emerin- and lamin-A/C-null cells have decreased nuclear 4.1R. Our data provide evidence that 4.1R has important functional interactions with emerin and A-type lamin that impact upon nuclear architecture, centrosome-nuclear envelope association and the regulation of β-catenin transcriptional co-activator activity that is dependent on β-catenin nuclear export.
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Affiliation(s)
- Adam J Meyer
- Department of Genome Dynamics, University of California, Berkeley, CA 94720, USA
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41
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Mitotic defects lead to pervasive aneuploidy and accompany loss of RB1 activity in mouse LmnaDhe dermal fibroblasts. PLoS One 2011; 6:e18065. [PMID: 21464947 PMCID: PMC3064591 DOI: 10.1371/journal.pone.0018065] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Accepted: 02/18/2011] [Indexed: 12/28/2022] Open
Abstract
Background Lamin A (LMNA) is a component of the nuclear lamina and is mutated in several human diseases, including Emery-Dreifuss muscular dystrophy (EDMD; OMIM ID# 181350) and the premature aging syndrome Hutchinson-Gilford progeria syndrome (HGPS; OMIM ID# 176670). Cells from progeria patients exhibit cell cycle defects in both interphase and mitosis. Mouse models with loss of LMNA function have reduced Retinoblastoma protein (RB1) activity, leading to aberrant cell cycle control in interphase, but how mitosis is affected by LMNA is not well understood. Results We examined the cell cycle and structural phenotypes of cells from mice with the Lmna allele, Disheveled hair and ears (LmnaDhe). We found that dermal fibroblasts from heterozygous LmnaDhe (LmnaDhe/+) mice exhibit many phenotypes of human laminopathy cells. These include severe perturbations to the nuclear shape and lamina, increased DNA damage, and slow growth rates due to mitotic delay. Interestingly, LmnaDhe/+ fibroblasts also had reduced levels of hypophosphorylated RB1 and the non-SMC condensin II-subunit D3 (NCAP-D3), a mitosis specific centromere condensin subunit that depends on RB1 activity. Mitotic check point control by mitotic arrest deficient-like 1 (MAD2L1) also was perturbed in LmnaDhe/+ cells. LmnaDhe/+ fibroblasts were consistently aneuploid and had higher levels of micronuclei and anaphase bridges than normal fibroblasts, consistent with chromosome segregation defects. Conclusions These data indicate that RB1 may be a key regulator of cellular phenotype in laminopathy-related cells, and suggest that the effects of LMNA on RB1 include both interphase and mitotic cell cycle control.
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Verhaert D, Richards K, Rafael-Fortney JA, Raman SV. Cardiac involvement in patients with muscular dystrophies: magnetic resonance imaging phenotype and genotypic considerations. Circ Cardiovasc Imaging 2011; 4:67-76. [PMID: 21245364 DOI: 10.1161/circimaging.110.960740] [Citation(s) in RCA: 139] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- David Verhaert
- Davis Heart and Lung Research Institute, Ohio State University, Columbus, Ohio, USA
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43
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Abstract
The nuclear envelope (NE) is a highly regulated membrane barrier that separates the nucleus from the cytoplasm in eukaryotic cells. It contains a large number of different proteins that have been implicated in chromatin organization and gene regulation. Although the nuclear membrane enables complex levels of gene expression, it also poses a challenge when it comes to cell division. To allow access of the mitotic spindle to chromatin, the nucleus of metazoans must completely disassemble during mitosis, generating the need to re-establish the nuclear compartment at the end of each cell division. Here, I summarize our current understanding of the dynamic remodeling of the NE during the cell cycle.
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Affiliation(s)
- Martin W Hetzer
- Salk Institute for Biological Studies, Molecular and Cell Biology Laboratory, La Jolla, California 92037, USA.
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44
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Abstract
One of the many debated topics in ageing research is whether progeroid syndromes are really accelerated forms of human ageing. The answer requires a better understanding of the normal ageing process and the molecular pathology underlying these rare diseases. Exciting recent findings regarding a severe human progeria, Hutchinson-Gilford progeria syndrome, have implicated molecular changes that are also linked to normal ageing, such as genome instability, telomere attrition, premature senescence and defective stem cell homeostasis in disease development. These observations, coupled with genetic studies of longevity, lead to a hypothesis whereby progeria syndromes accelerate a subset of the pathological changes that together drive the normal ageing process.
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45
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Reich A, Meurer M, Eckes B, Friedrichs J, Muller DJ. Surface morphology and mechanical properties of fibroblasts from scleroderma patients. J Cell Mol Med 2010; 13:1644-1652. [PMID: 18624756 DOI: 10.1111/j.1582-4934.2008.00401.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Overproduction of extracellular matrix components by fibroblasts plays a key role in the pathogenesis of scleroderma. To investigate whether these functional alterations are accompanied by changes in the mechanical properties and morphology of fibroblast, atomic force microscopy was applied to dermal fibroblasts derived either from scleroderma patients or from healthy donors. No significant morphological differences could be observed among the different cell strains showing long cytoskeleton fibres similar in length and irregularly distributed protrusions on the cell surface. In contrast, significant differences in cellular stiffness of dermal fibroblasts derived from scleroderma lesions were detected. Compared to fibroblasts from healthy donors, diseased cells were characterized by a reduced elastic constant both when the global and local mechanical properties were probed. The altered stiffness of scleroderma fibroblasts may be important in the pathogenesis of the disease as it could lead to the abnormal response of fibroblasts to mechanical stimuli.
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Affiliation(s)
- Adam Reich
- Department of Dermatology, Venereology and Allergology, Wroclaw Medical University, Wroclaw, Poland.,Department of Dermatology, Carl Gustav Carus Medical Faculty, University of Technology, Dresden, Germany.,Biotechnology Center, University of Technology, Dresden, Germany
| | - Michael Meurer
- Department of Dermatology, Carl Gustav Carus Medical Faculty, University of Technology, Dresden, Germany
| | - Beate Eckes
- Department of Dermatology, University of Cologne, Cologne, Germany
| | - Jens Friedrichs
- Biotechnology Center, University of Technology, Dresden, Germany
| | - Daniel J Muller
- Biotechnology Center, University of Technology, Dresden, Germany
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Khatau SB, Kim DH, Hale CM, Bloom RJ, Wirtz D. The perinuclear actin cap in health and disease. Nucleus 2010; 1:337-42. [PMID: 21327082 DOI: 10.4161/nucl.1.4.12331] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Revised: 04/16/2010] [Accepted: 04/23/2010] [Indexed: 01/11/2023] Open
Abstract
We recently demonstrated the existence of a previously uncharacterized subset of actomyosin fibers that form the perinuclear actin cap, a cytoskeletal structure that tightly wraps around the nucleus of a wide range of somatic cells. Fibers in the actin cap are distinct from well-characterized, conventional actin fibers at the basal and dorsal surfaces of adherent cells in their subcellular location, internal organization, dynamics, ability to generate contractile forces, response to cytoskeletal pharmacological treatments, response to biochemical stimuli, regulation by components of the linkers of nucleoskeleton and cytoskeleton (LINC) complexes, and response to disease-associated mutations in LMNA, the gene that encodes for the nuclear lamin component lamin A/C. The perinuclear actin cap precisely shapes the nucleus in interphase cells. The perinuclear actin cap may also be a mediator of microenvironment mechanosensing and mechanotransduction, as well as a regulator of cell motility, polarization and differentiation.
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Affiliation(s)
- Shyam B Khatau
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, MD, USA
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47
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In the middle of it all: Mutual mechanical regulation between the nucleus and the cytoskeleton. J Biomech 2010; 43:2-8. [DOI: 10.1016/j.jbiomech.2009.09.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2009] [Indexed: 12/28/2022]
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48
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Li B, Jog S, Candelario J, Reddy S, Comai L. Altered nuclear functions in progeroid syndromes: a paradigm for aging research. ScientificWorldJournal 2009; 9:1449-62. [PMID: 20024518 PMCID: PMC4213125 DOI: 10.1100/tsw.2009.159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Syndromes of accelerated aging could provide an entry point for identifying and dissecting the cellular pathways that are involved in the development of age-related pathologies in the general population. However, their usefulness for aging research has been controversial, as it has been argued that these diseases do not faithfully reflect the process of natural aging. Here we review recent findings on the molecular basis of two progeroid diseases, Werner syndrome (WS) and Hutchinson-Gilford progeria syndrome (HGPS), and highlight functional connections to cellular processes that may contribute to normal aging.
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Affiliation(s)
- Baomin Li
- Department of Molecular Microbiology and Immunology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, USA
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Abstract
Defects in nuclear morphology often correlate with the onset of disease, including cancer, progeria, cardiomyopathy, and muscular dystrophy. However, the mechanism by which a cell controls its nuclear shape is unknown. Here, we use adhesive micropatterned surfaces to control the overall shape of fibroblasts and find that the shape of the nucleus is tightly regulated by the underlying cell adhesion geometry. We found that this regulation occurs through a dome-like actin cap that covers the top of the nucleus. This cap is composed of contractile actin filament bundles containing phosphorylated myosin, which form a highly organized, dynamic, and oriented structure in a wide variety of cells. The perinuclear actin cap is specifically disorganized or eliminated by inhibition of actomyosin contractility and rupture of the LINC complexes, which connect the nucleus to the actin cap. The organization of this actin cap and its nuclear shape-determining function are disrupted in cells from mouse models of accelerated aging (progeria) and muscular dystrophy with distorted nuclei caused by alterations of A-type lamins. These results highlight the interplay between cell shape, nuclear shape, and cell adhesion mediated by the perinuclear actin cap.
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Chen S, Martin C, Maya-Mendoza A, Tang CW, Lovrić J, Sims PFG, Jackson DA. Reduced Expression of Lamin A/C Results in Modified Cell Signaling and Metabolism Coupled with Changes in Expression of Structural Proteins. J Proteome Res 2009; 8:5196-211. [DOI: 10.1021/pr900549a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Songbi Chen
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Catherine Martin
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Apolinar Maya-Mendoza
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Chi W. Tang
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Josip Lovrić
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Paul F. G. Sims
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Dean A. Jackson
- Faculty of Life Sciences, Manchester Interdisciplinary Biocentre, University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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