Plasma Gelsolin-Induced Fibroblast Activation: Insights from an In Vitro Study
Daisuke Inoue1,2, Meshach Asare-Werehene1,3,4,5, Emma Gerber1,3, Kazuhiro Okamoto1, Yoshio Yoshida1,2, Benjamin K Tsang1,3,4.
1Chronic Disease Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; 2Department of Obstetrics and Gynecology, University of Fukui, Fukui, Japan; 3Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada; 4Department of Obstetrics & Gynecology, & The Centre for Infection, Immunity and Inflammation (CI3), University of Ottawa, Ottawa, ON, Canada; 5Department of Laboratory Medicine and Pathobiology, University of Toronto, Tronto, ON, Canada
Introduction: Cancer associated fibroblasts (CAFs) play a crucial role in cancer chemoresistance. Although plasma gelsolin (pGSN) is implicated in ovarian cancer (OVCA) chemoresistance, it impacts on CAFs within the ovarian tumor microenvironment (TME) is poorly elucidated. This study aims to investigate pGSN-mediated fibroblast activation in vitro, providing a foundational understanding of OVCA chemoresistance.
Methods: Human fibroblast cell lines were cultured with various concentrations (0, 2.5, 5, 10, 20, 40 µM) of recombinant human pGSN (rhpGSN) for different durations (24 - 48 hours). Fibroblast activation was examined by measuring α-Smooth Muscle Actin (αSMA) content by Western Blotting (WB) and changes in fibroblast morphology using the ratio of cells with multiple cytoplasmic projections to spindle shaped cells.
Results: Treatment of fibroblasts with exogenous rhpGSN resulted in a concentration- and time-dependent increase in αSMA content, with the most significant elevation (7.2-fold) observed at the 20 µM concentration(p < 0.0001). Pronounced activation of fibroblasts was observed at 48 hours post-treatment. Moreover, significant shift in cellular morphology was observed with increasing the ratio of cells with multiple cytoplasmic projections to spindle-shaped cells (p = 0.01).
Conclusions: Our in vitro findings demonstrate that pGSN significantly activate fibroblasts, as evidenced by increased αSMA content and increase of fibroblast cell population exhibiting multiple cellular projections. Our ongoing investigations are specifically examining how OVCA cells, with modulated pGSN expression, influence fibroblasts in TME. The findings from this study will uncover the mechanistic pathways through which pGSN influences the chemoresistance phenotype within the TME, potentially unveiling new targets for therapeutic intervention. (Supported in part by grant from CIHR)