An in vitro injury model to examine pericyte‐skeletal muscle cell cross talk

Abstract

This study aimed to evaluate an in vitro model of cross talk between pericytes and skeletal muscle cells following scrape injury. Nuclear factor‐kappa B (NF‐κB) and monocyte chemoattractant protein‐1 (MCP‐1) are important in the in vivo response to muscle stress and were chosen to evaluate the model. C2C12 cells were co‐cultured with human primary pericytes (HPPs) in transwell inserts. Nuclear NF‐κB/p65 DNA binding activity and MCP‐1 concentration were quantified via ELISA at baseline (BSLN), 3h, 6h, and 24h following scrape injury (INJ) to C2C12 cells. In C2C12 cells, p65 DNA binding activity was significantly elevated at 3h (2.5 fold, p=0.027) and 24h (3.57 fold, p=0.001), relative to BSLN, with no effect of INJ (p=0.698) relative to CON. In HPPs, p65 DNA binding activity was increased relative to BSLN at 6h (2.0 fold, p=0.007), and 24h (2.33 fold, p=0.001). HPPs trended towards greater p65 DNA binding activity in INJ compared to CON (p=0.085) and in comparison to C2C12 cells (p=0.079). At 24h, HPP MCP‐1 secretion was first detected and exceeded C2C12 MCP‐1 secretion (2.1 fold, p<0.001). These data reveal 1) this model is useful for evaluating secreted proteins involved in pericyte‐skeletal muscle cross talk, which are mostly unknown at this time, and 2) novel information regarding HPP MCP‐1 secretion in response to C2C12 scrape injury. This research was supported by an ACSM Foundation Doctoral Student Research Grant.