Role of ROCK isoforms in regulation of stiffness induced myofibroblast differentiation in lung fibrosis

Htwe, Su S. and Cha, Byung H. and Yue, Kan and Khademhosseini, Ali and Knox, Alan J. and Ghaemmaghami, Amir M. (2017) Role of ROCK isoforms in regulation of stiffness induced myofibroblast differentiation in lung fibrosis. American Journal of Respiratory Cell and Molecular Biology, 56 (6). ISSN 1535-4989

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Abstract

Fibrosis is a major cause of progressive organ dysfunction in several chronic pulmonary diseases. Rho associated coiled-coil forming kinase (ROCK) has shown to be involved in myofibroblast differentiation driven by altered matrix stiffness in fibrotic state. There are two known ROCK isoforms in human, ROCK1 (ROKβ) and ROCK2 (ROKα), but specific role of each isoform in myofibroblast differentiation in lung fibrosis remains unknown. To study this, we developed a Gelatin methacryloyl (GelMA) hydrogel based culture system with different stiffness levels relevant to healthy and fibrotic lungs. We have shown that stiff matrix and not soft matrix, can induce myofibroblast differentiation with high αSMA expression. Furthermore, our data confirm that the inhibition of ROCK signalling by a pharmacological inhibitor (i.e. Y27632) attenuates stiffness induced αSMA expression and fibre assembly in myofibroblasts. To assess the role of ROCK isoforms in this process we used siRNA to knock down the expression of each isoform. Our data showed that knocking down either ROCK1 or ROCK2 did not result in a reduction in αSMA expression in myofibroblasts on stiff matrix as opposed to soft matrix where αSMA expression was reduced significantly. Paradoxically, on stiff matrix, the absence of one isoform (particularly ROCK2) exaggerated αSMA expression and led to thick fibre assembly. Moreover complete loss of αSMA fibre assembly was seen only in the absence of both ROCK isoforms suggesting that both isoforms are implicated in this process. Overall our results indicate the differential role of ROCK isoforms in myofibroblast differentiation on soft and stiff matrices.

Item Type: Article
Schools/Departments: University of Nottingham, UK > Faculty of Medicine and Health Sciences > School of Life Sciences > School of Molecular Medical Sciences > Immunology
University of Nottingham, UK > Faculty of Medicine and Health Sciences > School of Medicine > Division of Respiratory Medicine
Identification Number: 10.1165/rcmb.2016-0306OC
Depositing User: Eprints, Support
Date Deposited: 28 Feb 2017 13:04
Last Modified: 14 Oct 2017 21:41
URI: http://eprints.nottingham.ac.uk/id/eprint/40910

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