Decreasing Wound Edge Stress Enhances Leader Cell Formation during Collective Smooth Muscle Cell Migration

ACS Biomater Sci Eng. 2019 Aug 12;5(8):3864-3875. doi: 10.1021/acsbiomaterials.8b01222. Epub 2019 Mar 14.

Abstract

Collective cell migration is vital to tissue remodeling in wound repair, development, and cancer invasion. Nevertheless, studies on collective cell migration have largely focused on epithelial growth and repair mechanisms and have only recently expanded to explore coordinated metastatic cancer and smooth muscle cell behaviors. The regulatory mechanisms of smooth muscle cell collective migration, such as leader-follower organization and mechanosensitivity, remain poorly understood. In this study, we demonstrate the involvement of leader cells during collective smooth muscle cell migration using dynamic cell tracking and single cell gene expression analysis. Engineered wound models, including ingrowth, outgrowth, and straight edge geometries, along with traction force microscopy and finite element stress mapping reveal that smooth muscle leader cells are enhanced at the wound edge when the intercellular tension near the cell wound boundary is reduced. Pharmacological perturbation further supports the notion that mechanical force negatively regulates the formation of leader cells. The mechanical regulation of collective smooth muscle cell migration via the formation of leader cells may lead to novel treatment strategies for pathogenic smooth muscle cell conditions in the future.

Keywords: collective cell migration; leader cell; single cell; smooth muscle; traction force; wound healing.