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Biology subjects

Rahaman, S. G.

Publications and source records attributed to Rahaman, S. G..

2 recordsLinked to original sources

TRPV4 channel contributes to aortic root stiffening and atherosclerotic lesion development

Cardiovascular disease is the number one cause of death in the developed world and atherosclerosis, a chronic arterial disease, is the most dominant underlying pathology. Epidemiologic and experimental studies suggest that arterial stiffness is a risk factor for atherosclerosis. However, there has been surprisingly limited development in mechanistic understanding of the generation of arterial stiffness and little progress in understanding the mechanisms by which matrix stiffening drives the development of atherosclerosis. Various proinflammatory and fibrotic activities of macrophages and fibroblasts, such as migration, inflammatory gene expression, and myofibroblast activation, are influenced by matrix stiffness. This influence suggests that aorta stiffening may regulate atherosclerosis via a cellular stiffness sensor. Our research indicates that mechanosensitive transient receptor potential vanilloid 4 (TRPV4) channels control inflammation and fibrosis in other organs and regulate macrophage and fibroblast activation, implicating TRPV4 as a potential stiffness sensor in atherosclerosis. This suggests a cycle where inflammation, fibrosis, and tissue stiffening reinforce each other, with macrophages playing a key role. Here, we identify a cellular stiffness sensor linking matrix stiffness and atherosclerosis using human aortic tissues, a murine atherosclerosis model, and atomic force microscopy (AFM) analysis. This novel finding suggests that targeting TRPV4 could be a selective strategy to prevent or suppress atherogenesis.

pathology↗

TRPV4-mediated Mechanotransduction Regulates the Differentiation of Valvular Interstitial Cells to Myofibroblasts: Implications for Aortic Stenosis

As aortic valve stenosis (AVS) progresses, the valve tissue also stiffens. This increase in tissue stiffness causes the valvular interstitial cells (VICs) to transform into myofibroblasts in response. VIC-to-myofibroblast differentiation is critically involved in the development of AVS. Herein, we investigated the role of mechanosensitive Ca2+-permeant transient receptor potential vanilloid 4 (Trpv4) channels in matrix stiffness- and transforming growth factor {beta}1 (TGF{beta}1)-induced VIC-myofibroblast activation. We confirmed Trpv4 functionality in primary mouse wild-type VICs compared to Trpv4 null VICs using live Ca2+ influx detection during application of its selective agonist and antagonist. Using physiologically relevant hydrogels of varying stiffness that respectively mimic healthy or diseased aortic valve tissue stiffness, we found that genetic ablation of Trpv4 blocked matrix stiffness- and TGF{beta}1-induced VIC-myofibroblast activation as determined by changes in morphology, alterations of expression of -smooth muscle actin, and modulations of F-actin generation. Our results showed that N-terminal residues 30-130 in Trpv4 were crucial for cellular force generation and VIC-myofibroblast activation, while deletion of residues 1-30 had no noticeable negative effect on these processes. Collectively, these data suggest a differential regulatory role for Trpv4 in stiffness/TGF{beta}1-induced VIC-myofibroblast activation. Our data further showed that Trpv4 regulates stiffness/TGF{beta}1-induced PI3K-AKT activity that is required for VIC-myofibroblast differentiation and cellular force generation, suggesting a mechanism by which Trpv4 activity regulates VIC-myofibroblast activation. Altogether, these data identify a novel role for Trpv4 mechanotransduction in regulating VIC-myofibroblast activation, implicating Trpv4 as a potential therapeutic target to slow and/or reverse AVS development.

cell biology↗