Laminar shear stress‐provoked cytoskeletal changes are mediated by epigenetic reprogramming of TIMP1 in human primary smooth muscle cells

Abstract

Whereas endothelial responses to shear stress are well-characterized, the cell physiological effects of shear stress in smooth muscle cells (SMCs) remain largely obscure. As SMCs are directly challenged by shear stress after endothelial denuding injury following procedures such as angioplasty or endarterectomy, characterization of these responses represents an important scientific question. Hence we decided to contrast cytoskeletal reorganization, epigenetic reprogramming, signaling transduction, and changes in miRNA (miRs) profiles in primary human aortic smooth muscle cells (AoSMCs) between unstressed cells and cells exposed to shear stress. We observed that shear stress-provoked reorganization of the actin cytoskeleton in an apparently Cofilin-dependent fashion and which related to altered integrin signaling, apparently caused by remodeling of the extracellular matrix. The latter appeared a downstream effect of increased expression of matrix metalloproteinases and downregulation of tissue metalloproteinase inhibitor 1 (TIMP1) protein levels. In turn, these effects related to shear stress-provoked changes in expression and nuclear localization of the epigenetic regulators demethylases TET1, TET2, DNMT1, DNMT3A and DNMT3B, HDAC6, and SIRT1. Accordingly, TIMP1 promotor CpG hypomethylation was a prominent effect, and resulted in a significant increase in TIMP1 transcription, which may also have related increased expression of miRs involved in modulating TIMP1 translation. Thus epigenetic-reprogramming of TIMP1 emerges as critical element in smooth muscle responses to mechanical signals and as epigenetic machinery is amendable to pharmacological manipulation, this pathway may have important clinical consequences. K E Y W O R D S aortic smooth muscle cells, cytoskeleton, ECM, endothelium, epigenetic, TIMP J Cell Physiol. 2019;234:6382-6396. wileyonlinelibrary.com/journal/jcp 6382 |

Wortmannin targeting phosphatidylinositol 3‐kinase suppresses angiogenic factors in shear‐stressed endothelial cells

“…In conjunction, these findings in driving adaptive behavior to SS recapitulate the survival signaling required during cell adhesion (Zambuzzi et al, ; Zambuzzi, Milani, & Teti, ; Bertazzo, Zambuzzi, Campos, Ogeda et al, ; Bertazzo, Zambuzzi, Campos, Ferreira, & Bertran, ; Zambuzzi, Coelho, Alves, & Granjeiro, ; Zambuzzi, Ferreira, Granjeiro, & Aoyama, ; Fernandes et al, ; Zambuzzi et al, ; Baroncelli et al, ). To note, the signaling culminating on modulation of cofilin phosphorylation is majority pathway during β‐actin rearrangement (da Silva et al, ; Silva et al, ; Zambuzzi et al, ), and as actin peripherally contributes with the integrin roles, its seems sensate to require their involvement during adaptive effect in response to tensional forces.…”

“…To better of our understanding, alternative methodologies to study cellular and molecular behavior of EC responding to SS are necessaries, as that proposed by dela Paz, Walshe, Leach, Saint‐Geniez, and D'Amore (), where the authors mimic SS forces by using an orbital rotation into the cell culture incubator challenging monolayer of EC. We have earlier modified this methodology to suggest epigenetic machinery in modulating TIMP1 expression in smooth muscle cells (da Silva et al, ), as well as identifying the signaling mechanism in endothelial cell responding to a circuit of tensional forces (Pinto et al, ). Mechanotransduction comprehends cellular processes occurring in response to physical and mechanical stimuli, transforming them into biochemical signals culminating in a physiological response (Zhang, ).…”

LncRNA HOTAIR is a novel endothelial mechanosensitive gene

“…Human primary endothelial cells were purchased and cultured as recommended by the manufacturer. The cells were replicated and subjected to the shear stress model, as we previously proposed (da Silva et al ). To investigate whether lncRNA HOTAIR and HOTTIP were mechanosensitive genes, we also subjected the cells in a circuit of tensional forces by incrementing the centrifuge speed respecting a ramp every 15 min, then the biological samples were harvested and forwarded to further analyses.…”

Updating the role of matrix metalloproteinases in mineralized tissue and related diseases

“…Therefore, we have defined a novel-signaling pathway responsible for the physiological adaptation of vessel smooth muscle to changes in mechanical pressure, which are potentially relevant for defining novel avenues for the rational treatment of diseases. 113 Chemical-motivated inhibitors of MMPs have been shown to be promising strategies for cardio-protection.…”