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Faleeva M, Ahmad S, Theofilatos K, Lynham S, Watson G, Whitehead M, Marhuenda E, Iskratsch T, Cox S, Shanahan CM. Sox9 Accelerates Vascular Aging by Regulating Extracellular Matrix Composition and Stiffness. Circ Res 2024; 134:307-324. [PMID: 38179698 PMCID: PMC10826924 DOI: 10.1161/circresaha.123.323365] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 12/21/2023] [Accepted: 12/30/2023] [Indexed: 01/06/2024]
Abstract
BACKGROUND Vascular calcification and increased extracellular matrix (ECM) stiffness are hallmarks of vascular aging. Sox9 (SRY-box transcription factor 9) has been implicated in vascular smooth muscle cell (VSMC) osteo/chondrogenic conversion; however, its relationship with aging and calcification has not been studied. METHODS Immunohistochemistry was performed on human aortic samples from young and aged patients. Young and senescent primary human VSMCs were induced to produce ECM, and Sox9 expression was manipulated using adenoviral overexpression and depletion. ECM properties were characterized using atomic force microscopy and proteomics, and VSMC phenotype on hydrogels and the ECM were examined using confocal microscopy. RESULTS In vivo, Sox9 was not spatially associated with vascular calcification but correlated with the senescence marker p16 (cyclin-dependent kinase inhibitor 2A). In vitro Sox9 showed mechanosensitive responses with increased expression and nuclear translocation in senescent cells and on stiff matrices. Sox9 was found to regulate ECM stiffness and organization by orchestrating changes in collagen (Col) expression and reducing VSMC contractility, leading to the formation of an ECM that mirrored that of senescent cells. These ECM changes promoted phenotypic modulation of VSMCs, whereby senescent cells plated on ECM synthesized from cells depleted of Sox9 returned to a proliferative state, while proliferating cells on a matrix produced by Sox9 expressing cells showed reduced proliferation and increased DNA damage, reiterating features of senescent cells. LH3 (procollagen-lysine, 2-oxoglutarate 5-dioxygenase 3) was identified as an Sox9 target and key regulator of ECM stiffness. LH3 is packaged into extracellular vesicles and Sox9 promotes extracellular vesicle secretion, leading to increased LH3 deposition within the ECM. CONCLUSIONS These findings highlight the crucial role of ECM structure and composition in regulating VSMC phenotype. We identify a positive feedback cycle, whereby cellular senescence and increased ECM stiffening promote Sox9 expression, which, in turn, drives further ECM modifications to further accelerate stiffening and senescence.
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Affiliation(s)
- Maria Faleeva
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
| | - Sadia Ahmad
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
| | - Konstantinos Theofilatos
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
| | - Steven Lynham
- Proteomics Facility, Centre of Excellence for Mass Spectrometry (S.L.) King’s College London, United Kingdom
| | - Gabriel Watson
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
| | - Meredith Whitehead
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
| | - Emilie Marhuenda
- School of Engineering and Material Science, Queen Mary University of London, United Kingdom (E.M., T.I.)
| | - Thomas Iskratsch
- School of Engineering and Material Science, Queen Mary University of London, United Kingdom (E.M., T.I.)
| | - Susan Cox
- Randall Centre for Cell & Molecular Biophysics, Faculty of Life Sciences & Medicine (S.C.) King’s College London, United Kingdom
| | - Catherine M. Shanahan
- British Heart Foundation (BHF) Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences (M.F., S.A., K.T., G.W., M.W., C.M.S.) King’s College London, United Kingdom
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Hartinger R, Lederer EM, Schena E, Lattanzi G, Djabali K. Impact of Combined Baricitinib and FTI Treatment on Adipogenesis in Hutchinson-Gilford Progeria Syndrome and Other Lipodystrophic Laminopathies. Cells 2023; 12:1350. [PMID: 37408186 DOI: 10.3390/cells12101350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/27/2023] [Accepted: 05/04/2023] [Indexed: 07/07/2023] Open
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disease that causes premature aging symptoms, such as vascular diseases, lipodystrophy, loss of bone mineral density, and alopecia. HGPS is mostly linked to a heterozygous and de novo mutation in the LMNA gene (c.1824 C > T; p.G608G), resulting in the production of a truncated prelamin A protein called "progerin". Progerin accumulation causes nuclear dysfunction, premature senescence, and apoptosis. Here, we examined the effects of baricitinib (Bar), an FDA-approved JAK/STAT inhibitor, and a combination of Bar and lonafarnib (FTI) treatment on adipogenesis using skin-derived precursors (SKPs). We analyzed the effect of these treatments on the differentiation potential of SKPs isolated from pre-established human primary fibroblast cultures. Compared to mock-treated HGPS SKPs, Bar and Bar + FTI treatments improved the differentiation of HGPS SKPs into adipocytes and lipid droplet formation. Similarly, Bar and Bar + FTI treatments improved the differentiation of SKPs derived from patients with two other lipodystrophic diseases: familial partial lipodystrophy type 2 (FPLD2) and mandibuloacral dysplasia type B (MADB). Overall, the results show that Bar treatment improves adipogenesis and lipid droplet formation in HGPS, FPLD2, and MADB, indicating that Bar + FTI treatment might further ameliorate HGPS pathologies compared to lonafarnib treatment alone.
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Affiliation(s)
- Ramona Hartinger
- Epigenetics of Aging, Department of Dermatology and Allergy, TUM School of Medicine, Munich Institute of Biomedical Engineering (MIBE), Technical University of Munich (TUM), 85748 Garching, Germany
| | - Eva-Maria Lederer
- Epigenetics of Aging, Department of Dermatology and Allergy, TUM School of Medicine, Munich Institute of Biomedical Engineering (MIBE), Technical University of Munich (TUM), 85748 Garching, Germany
| | - Elisa Schena
- Unit of Bologna, CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", 40136 Bologna, Italy
- IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Giovanna Lattanzi
- Unit of Bologna, CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", 40136 Bologna, Italy
- IRCCS Istituto Ortopedico Rizzoli, 40136 Bologna, Italy
| | - Karima Djabali
- Epigenetics of Aging, Department of Dermatology and Allergy, TUM School of Medicine, Munich Institute of Biomedical Engineering (MIBE), Technical University of Munich (TUM), 85748 Garching, Germany
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3
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Primmer SR, Liao CY, Kummert OMP, Kennedy BK. Lamin A to Z in normal aging. Aging (Albany NY) 2022; 14:8150-8166. [PMID: 36260869 DOI: 10.18632/aging.204342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 08/31/2022] [Indexed: 11/25/2022]
Abstract
Almost since the discovery that mutations in the LMNA gene, encoding the nuclear structure components lamin A and C, lead to Hutchinson-Gilford progeria syndrome, people have speculated that lamins may have a role in normal aging. The most common HPGS mutation creates a splice variant of lamin A, progerin, which promotes accelerated aging pathology. While some evidence exists that progerin accumulates with normal aging, an increasing body of work indicates that prelamin A, a precursor of lamin A prior to C-terminal proteolytic processing, accumulates with age and may be a driver of normal aging. Prelamin A shares properties with progerin and is also linked to a rare progeroid disease, restrictive dermopathy. Here, we describe mechanisms underlying changes in prelamin A with aging and lay out the case that this unprocessed protein impacts normative aging. This is important since intervention strategies can be developed to modify this pathway as a means to extend healthspan and lifespan.
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Affiliation(s)
| | - Chen-Yu Liao
- The Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Brian K Kennedy
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Centre for Healthy Longevity, National University Health System, Singapore.,Departments of Biochemistry and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Hodson N, Mazzulla M, Holowaty MNH, Kumbhare D, Moore DR. RPS6 phosphorylation occurs to a greater extent in the periphery of human skeletal muscle fibers, near focal adhesions, after anabolic stimuli. Am J Physiol Cell Physiol 2021; 322:C94-C110. [PMID: 34852208 DOI: 10.1152/ajpcell.00357.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Following anabolic stimuli (mechanical loading and/or amino acid provision) the mechanistic target of rapamycin complex 1 (mTORC1), a master regulator of protein synthesis, translocates toward the cell periphery. However, it is unknown if mTORC1-mediated phosphorylation events occur in these peripheral regions or prior to translocation (i.e. in central regions). We therefore aimed to determine the cellular location of a mTORC1-mediated phosphorylation event, RPS6Ser240/244, in human skeletal muscle following anabolic stimuli. Fourteen young, healthy males either ingested a protein-carbohydrate beverage (0.25g/kg protein, 0.75g/kg carbohydrate) alone (n=7;23±5yrs;76.8±3.6kg;13.6±3.8%BF, FED) or following a whole-body resistance exercise bout (n=7;22±2yrs;78.1±3.6kg;12.2±4.9%BF, EXFED). Vastus lateralis muscle biopsies were obtained at rest (PRE) and 120 and 300min following anabolic stimuli. RPS6Ser240/244 phosphorylation measured by immunofluorescent staining or immunoblot was positively correlated (r=0.76, p<0.001). Peripheral staining intensity of p-RPS6Ser240/244 increased above PRE in both FED and EXFED at 120min (~54% and ~138% respectively, p<0.05) but was greater in EXFED at both post-stimuli time points (p<0.05). The peripheral-central ratio of p-RPS6240/244 staining displayed a similar pattern, even when corrected for total RPS6 distribution, suggesting RPS6 phosphorylation occurs to a greater extent in the periphery of fibers. Moreover, p-RPS6Ser240/244 intensity within paxillin-positive regions, a marker of focal adhesion complexes, was elevated at 120min irrespective of stimulus (p=0.006) before returning to PRE at 300min. These data confirm that RPS6Ser240/244 phosphorylation occurs in the region of human muscle fibers to which mTOR translocates following anabolic stimuli and identifies focal adhesion complexes as a potential site of mTORC1 regulation in vivo.
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Affiliation(s)
- Nathan Hodson
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Michael Mazzulla
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | - Maksym N H Holowaty
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
| | | | - Daniel R Moore
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada
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5
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Porter L, Minaisah RM, Ahmed S, Ali S, Norton R, Zhang Q, Ferraro E, Molenaar C, Holt M, Cox S, Fountain S, Shanahan C, Warren D. SUN1/2 Are Essential for RhoA/ROCK-Regulated Actomyosin Activity in Isolated Vascular Smooth Muscle Cells. Cells 2020; 9:cells9010132. [PMID: 31935926 PMCID: PMC7017107 DOI: 10.3390/cells9010132] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
Vascular smooth muscle cells (VSMCs) are the predominant cell type in the blood vessel wall. Changes in VSMC actomyosin activity and morphology are prevalent in cardiovascular disease. The actin cytoskeleton actively defines cellular shape and the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex, comprised of nesprin and the Sad1p, UNC-84 (SUN)-domain family members SUN1/2, has emerged as a key regulator of actin cytoskeletal organisation. Although SUN1 and SUN2 function is partially redundant, they possess specific functions and LINC complex composition is tailored for cell-type-specific functions. We investigated the importance of SUN1 and SUN2 in regulating actomyosin activity and cell morphology in VSMCs. We demonstrate that siRNA-mediated depletion of either SUN1 or SUN2 altered VSMC spreading and impaired actomyosin activity and RhoA activity. Importantly, these findings were recapitulated using aortic VSMCs isolated from wild-type and SUN2 knockout (SUN2 KO) mice. Inhibition of actomyosin activity, using the rho-associated, coiled-coil-containing protein kinase1/2 (ROCK1/2) inhibitor Y27632 or blebbistatin, reduced SUN2 mobility in the nuclear envelope and decreased the association between SUN2 and lamin A, confirming that SUN2 dynamics and interactions are influenced by actomyosin activity. We propose that the LINC complex exists in a mechanical feedback circuit with RhoA to regulate VSMC actomyosin activity and morphology.
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Affiliation(s)
- Lauren Porter
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Rose-Marie Minaisah
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Sultan Ahmed
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Seema Ali
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Rosemary Norton
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Qiuping Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Elisa Ferraro
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Chris Molenaar
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Mark Holt
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, King’s College London, London SE1 1YR, UK
| | - Susan Cox
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, King’s College London, London SE1 1YR, UK
| | - Samuel Fountain
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Catherine Shanahan
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Derek Warren
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
- Correspondence:
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6
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Abstract
Arterial aging engages a plethora of key signalling pathways that act in concert to induce vascular smooth muscle cell (VSMC) phenotypic changes leading to vascular degeneration and extracellular matrix degradation responsible for alterations of the mechanical properties of the vascular wall. This review highlights proof-of-concept examples of components of the extracellular matrix, VSMC receptors which connect extracellular and intracellular structures, and signalling pathways regulating changes in mechanotransduction and vascular homeostasis in aging. Furthermore, it provides a new framework for understanding how VSMC stiffness and adhesion to extracellular matrix contribute to arterial stiffness and how interactions with endothelial cells, platelets, and immune cells can regulate vascular aging. The identification of the key players of VSMC changes operating in large and small-sized arteries in response to increased mechanical load may be useful to better elucidate the causes and consequences of vascular aging and associated progression of hypertension, arteriosclerosis, and atherosclerosis.
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Affiliation(s)
- Patrick Lacolley
- INSERM, U1116, Faculte de Medecine, 9 Avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.,Université de Lorraine, Nancy, France
| | - Veronique Regnault
- INSERM, U1116, Faculte de Medecine, 9 Avenue de la forêt de Haye, CS 50184, 54505 Vandœuvre-lès-Nancy, France.,Université de Lorraine, Nancy, France
| | - Alberto P Avolio
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, 2 Technology Place, Macquarie University, Sydney, NSW 2109, Australia
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Shan F, Huang Z, Xiong R, Huang Q, Li J. HIF1α‐induced upregulation of KLF4 promotes migration of human vascular smooth muscle cells under hypoxia. J Cell Physiol 2019; 235:141-150. [PMID: 31270801 DOI: 10.1002/jcp.28953] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 05/20/2019] [Indexed: 12/19/2022]
Affiliation(s)
- Fabo Shan
- Molecular Biology Center, State Key Laboratory of Trauma, Burn and Combined Injury Research Institute of Surgery, Daping Hospital, Army Medical University Chongqing P.R. China
| | - Zhizhong Huang
- Molecular Biology Center, State Key Laboratory of Trauma, Burn and Combined Injury Research Institute of Surgery, Daping Hospital, Army Medical University Chongqing P.R. China
| | - Renping Xiong
- Molecular Biology Center, State Key Laboratory of Trauma, Burn and Combined Injury Research Institute of Surgery, Daping Hospital, Army Medical University Chongqing P.R. China
| | - Qing‐Yuan Huang
- Department of Cold Environmental Medicine College of High Altitude Military Medicine, Army Medical University Chongqing P.R. China
| | - Junxia Li
- State Key Laboratory of Trauma, Burns and Combined Injury, Second Department of Research Institute of Surgery Daping Hospital, Army Medical University Chongqing P.R. China
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Afewerki T, Ahmed S, Warren D. Emerging regulators of vascular smooth muscle cell migration. J Muscle Res Cell Motil 2019; 40:185-196. [PMID: 31254136 PMCID: PMC6726670 DOI: 10.1007/s10974-019-09531-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 06/21/2019] [Indexed: 12/30/2022]
Abstract
Vascular smooth muscle cells (VSMCs) are the predominant cell type in the blood vessel wall and normally adopt a quiescent, contractile phenotype. VSMC migration is tightly controlled, however, disease associated changes in the soluble and insoluble environment promote VSMC migration. Classically, studies investigating VSMC migration have described the influence of soluble factors. Emerging data has highlighted the importance of insoluble factors, including extracellular matrix stiffness and porosity. In this review, we will recap on the important signalling pathways that regulate VSMC migration and reflect on the potential importance of emerging regulators of VSMC function.
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Affiliation(s)
- TecLino Afewerki
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
| | - Sultan Ahmed
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
| | - Derek Warren
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ UK
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Wang M, Monticone RE, McGraw KR. Proinflammatory Arterial Stiffness Syndrome: A Signature of Large Arterial Aging. J Vasc Res 2018; 55:210-223. [PMID: 30071538 PMCID: PMC6174095 DOI: 10.1159/000490244] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/21/2018] [Indexed: 12/11/2022] Open
Abstract
Age-associated structural and functional remodeling of the arterial wall produces a productive environment for the initiation and progression of hypertension and atherosclerosis. Chronic aging stress induces low-grade proinflammatory signaling and causes cellular proinflammation in arterial walls, which triggers the structural phenotypic shifts characterized by endothelial dysfunction, diffuse intimal-medial thickening, and arterial stiffening. Microscopically, aged arteries exhibit an increase in arterial cell senescence, proliferation, invasion, matrix deposition, elastin fragmentation, calcification, and amyloidosis. These characteristic cellular and matrix alterations not only develop with aging but can also be induced in young animals under experimental proinflammatory stimulation. Interestingly, these changes can also be attenuated in old animals by reducing low-grade inflammatory signaling. Thus, mitigating age-associated proinflammation and arterial phenotype shifts is a potential approach to retard arterial aging and prevent the epidemic of hypertension and atherosclerosis in the elderly.
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Yang M, Fan Z, Wang F, Tian ZH, Ma B, Dong B, Li Z, Zhang M, Zhao W. BMP-2 enhances the migration and proliferation of hypoxia-induced VSMCs via actin cytoskeleton, CD44 and matrix metalloproteinase linkage. Exp Cell Res 2018; 368:248-257. [DOI: 10.1016/j.yexcr.2018.05.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Revised: 05/03/2018] [Accepted: 05/06/2018] [Indexed: 12/24/2022]
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Hays TT, Ma B, Zhou N, Stoll S, Pearce WJ, Qiu H. Vascular smooth muscle cells direct extracellular dysregulation in aortic stiffening of hypertensive rats. Aging Cell 2018; 17:e12748. [PMID: 29603864 PMCID: PMC5946086 DOI: 10.1111/acel.12748] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2018] [Indexed: 02/05/2023] Open
Abstract
Aortic stiffening is an independent risk factor that underlies cardiovascular morbidity in the elderly. We have previously shown that intrinsic mechanical properties of vascular smooth muscle cells (VSMCs) play a key role in aortic stiffening in both aging and hypertension. Here, we test the hypothesis that VSMCs also contribute to aortic stiffening through their extracellular effects. Aortic stiffening was confirmed in spontaneously hypertensive rats (SHRs) vs. Wistar‐Kyoto (WKY) rats in vivo by echocardiography and ex vivo by isometric force measurements in isolated de‐endothelized aortic vessel segments. Vascular smooth muscle cells were isolated from thoracic aorta and embedded in a collagen I matrix in an in vitro 3D model to form reconstituted vessels. Reconstituted vessel segments made with SHR VSMCs were significantly stiffer than vessels made with WKY VSMCs. SHR VSMCs in the reconstituted vessels exhibited different morphologies and diminished adaptability to stretch compared to WKY VSMCs, implying dual effects on both static and dynamic stiffness. SHR VSMCs increased the synthesis of collagen and induced collagen fibril disorganization in reconstituted vessels. Mechanistically, compared to WKY VSMCs, SHR VSMCs exhibited an increase in the levels of active integrin β1‐ and bone morphogenetic protein 1 (BMP1)‐mediated proteolytic cleavage of lysyl oxidase (LOX). These VSMC‐induced alterations in the SHR were attenuated by an inhibitor of serum response factor (SRF)/myocardin. Therefore, SHR VSMCs exhibit extracellular dysregulation through modulating integrin β1 and BMP1/LOX via SRF/myocardin signaling in aortic stiffening.
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Affiliation(s)
- Tristan T. Hays
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
| | - Ben Ma
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
| | - Ning Zhou
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
| | - Shaunrick Stoll
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
| | - William J. Pearce
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
| | - Hongyu Qiu
- Division of Physiology Department of Basic Sciences School of Medicine Loma Linda University Loma Linda CA USA
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Mandibuloacral dysplasia: A premature ageing disease with aspects of physiological ageing. Ageing Res Rev 2018; 42:1-13. [PMID: 29208544 DOI: 10.1016/j.arr.2017.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 11/09/2017] [Accepted: 12/01/2017] [Indexed: 01/12/2023]
Abstract
Mandibuloacral dysplasia (MAD) is a rare genetic condition characterized by bone abnormalities including localized osteolysis and generalized osteoporosis, skin pigmentation, lipodystrophic signs and mildly accelerated ageing. The molecular defects associated with MAD are mutations in LMNA or ZMPSTE24 (FACE1) gene, causing type A or type B MAD, respectively. Downstream of LMNA or ZMPSTE24 mutations, the lamin A precursor, prelamin A, is accumulated in cells and affects chromatin dynamics and stress response. A new form of mandibuloacral dysplasia has been recently associated with mutations in POLD1 gene, encoding DNA polymerase delta, a major player in DNA replication. Of note, involvement of prelamin A in chromatin dynamics and recruitment of DNA repair factors has been also determined under physiological conditions, at the border between stress response and cellular senescence. Here, we review current knowledge on MAD clinical and pathogenetic aspects and highlight aspects typical of physiological ageing.
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