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Ma B, Melton E, Wiener R, Zhou N, Wu W, Lai L, Wang C, Costa KD, Qiu H. Age and Blood Pressure Contribute to Aortic Cell and Tissue Stiffness Through Distinct Mechanisms. Hypertension 2022; 79:1777-1788. [PMID: 35766034 PMCID: PMC9308762 DOI: 10.1161/hypertensionaha.121.18950] [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: 11/16/2022]
Abstract
BACKGROUND Aortic stiffening is strongly associated with both aging and hypertension, but the underlying mechanisms remain unclear. We hypothesized that aging-induced aortic stiffness is mediated by a mechanism differing from hypertension. METHODS We conducted comprehensive in vivo and in vitro experiments using multiple rat models to dissect the different mechanisms of aortic stiffening mediated by aging and hypertension. RESULTS A time-course study in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) normotensive rats showed more pronounced aging-associated aortic stiffening in SHR versus WKY. Angiotensin II-induced hypertension was associated with more significant aortic stiffening in older versus young WKY rats. Hypertension aggravated aging effects on aortic wall thickness and extracellular matrix content, indicating combinational effects of aging and hypertension on aortic stiffening. Intrinsic stiffness of isolated aortic vascular smooth muscle cells (VSMCs) increased with age in WKY rats, although no significant difference between older SHR and older WKY VSMCs was observed in 2-dimensional culture, reconstituted 3-dimensional tissues were stiffer for older SHR versus older WKY. A selective inhibitor that reduced hypertension-mediated aortic stiffening did not decrease age-related stiffening in aortic VSMCs and aortic wall. Integrin β1 and SM22 (smooth muscle-specific SM22 protein) expression were negligibly changed in WKY VSMCs during aging but were markedly increased by hypertension in older versus young WKY VSMCs. A notable shift of filamin isoforms from B to A was detected in older WKY VSMCs. CONCLUSIONS Our results indicate distinct mechanisms mediating aging-associated aortic VSMC and vessel stiffness, providing new insights into aortic stiffening and the pathogenesis of hypertension in the elderly.
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Affiliation(s)
- Ben Ma
- Center for Molecular and Translational Medicine, Institute of Biomedical Sciences, Georgia State University, Atlanta, GA (B.M., E.M., W.W., L.L., H.Q.).,Division of Physiology, Department of Basic Sciences (B.M., N.Z., H.Q.), School of Medicine, Loma Linda University, CA
| | - Elaina Melton
- Center for Molecular and Translational Medicine, Institute of Biomedical Sciences, Georgia State University, Atlanta, GA (B.M., E.M., W.W., L.L., H.Q.)
| | - Robert Wiener
- Department of Medicine (Cardiology), Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York, NY (R.W., K.D.C.)
| | - Ning Zhou
- Division of Physiology, Department of Basic Sciences (B.M., N.Z., H.Q.), School of Medicine, Loma Linda University, CA
| | - Wenqian Wu
- Center for Molecular and Translational Medicine, Institute of Biomedical Sciences, Georgia State University, Atlanta, GA (B.M., E.M., W.W., L.L., H.Q.)
| | - Lo Lai
- Center for Molecular and Translational Medicine, Institute of Biomedical Sciences, Georgia State University, Atlanta, GA (B.M., E.M., W.W., L.L., H.Q.)
| | - Charles Wang
- Department of Basic Sciences & Center for Genomics (C.W.), School of Medicine, Loma Linda University, CA
| | - Kevin D Costa
- Department of Medicine (Cardiology), Cardiovascular Research Institute, Icahn School of Medicine at Mount Sinai, New York, NY (R.W., K.D.C.)
| | - Hongyu Qiu
- Center for Molecular and Translational Medicine, Institute of Biomedical Sciences, Georgia State University, Atlanta, GA (B.M., E.M., W.W., L.L., H.Q.).,Division of Physiology, Department of Basic Sciences (B.M., N.Z., H.Q.), School of Medicine, Loma Linda University, CA
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Hsp22 Deficiency Induces Age-Dependent Cardiac Dilation and Dysfunction by Impairing Autophagy, Metabolism, and Oxidative Response. Antioxidants (Basel) 2021; 10:antiox10101550. [PMID: 34679684 PMCID: PMC8533440 DOI: 10.3390/antiox10101550] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/19/2021] [Accepted: 09/27/2021] [Indexed: 02/04/2023] Open
Abstract
Heat shock protein 22 (Hsp22) is a small heat shock protein predominantly expressed in skeletal and cardiac muscle. Previous studies indicate that Hsp22 plays a vital role in protecting the heart against cardiac stress. However, the essential role of Hsp22 in the heart under physiological conditions remains largely unknown. In this study, we used an Hsp22 knockout (KO) mouse model to determine whether loss of Hsp22 impairs cardiac growth and function with increasing age under physiological conditions. Cardiac structural and functional alterations at baseline were measured using echocardiography and invasive catheterization in Hsp22 KO mice during aging transition compared to their age-matched wild-type (WT) littermates. Our results showed that Hsp22 deletion induced progressive cardiac dilation along with declined function during the aging transition. Mechanistically, the loss of Hsp22 impaired BCL-2-associated athanogene 3 (BAG3) expression and its associated cardiac autophagy, undermined cardiac energy metabolism homeostasis and increased oxidative damage. This study showed that Hsp22 played an essential role in the non-stressed heart during the early stage of aging, which may bring new insight into understanding the pathogenesis of age-related dilated cardiomyopathy.
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