The Planar Polarity Component VANGL2 Is a Key Regulator of Mechanosignaling.

Sek-Shir Cheong,Armando E Del Río Hernández,Charlotte H Dean,Sally Yunsun Kim,Matthew Hind,Mark Griffiths,Carlos Matellan,David C A Gaboriau,Khondoker M Akram

doi:10.3389/fcell.2020.577201

Abstract

VANGL2 is a component of the planar cell polarity (PCP) pathway, which regulates tissue polarity and patterning. The Vangl2Lp mutation causes lung branching defects due to dysfunctional actomyosin-driven morphogenesis. Since the actomyosin network regulates cell mechanics, we speculated that mechanosignaling could be impaired when VANGL2 is disrupted. Here, we used live-imaging of precision-cut lung slices (PCLS) from Vangl2Lp/+ mice to determine that alveologenesis is attenuated as a result of impaired epithelial cell migration. Vangl2Lp/+ tracheal epithelial cells (TECs) and alveolar epithelial cells (AECs) exhibited highly disrupted actomyosin networks and focal adhesions (FAs). Functional assessment of cellular forces confirmed impaired traction force generation in Vangl2Lp/+ TECs. YAP signaling in Vangl2Lp airway epithelium was reduced, consistent with a role for VANGL2 in mechanotransduction. Furthermore, activation of RhoA signaling restored actomyosin organization in Vangl2Lp/+, confirming RhoA as an effector of VANGL2. This study identifies a pivotal role for VANGL2 in mechanosignaling, which underlies the key role of the PCP pathway in tissue morphogenesis.

Highlights

The planar cell polarity (PCP) pathway is a non-canonical Wnt pathway, best known for controlling the collective polarization of cells across the plane of a cell sheet, a phenomenon referred to as PCP
This study demonstrates that VANGL2 has an important role in mechanosignaling, which underlies the key functions of PCP pathway in regulating tissue morphogenesis and repair
Using the precision-cut lung slices (PCLSi) technique recently established by our team (Akram et al, 2019a), we investigated whether the alveologenesis defects we previously reported in Vangl2Lp/+ mice were due to impaired cell migration (Poobalasingam et al, 2017)

Summary

INTRODUCTION

The planar cell polarity (PCP) pathway is a non-canonical Wnt pathway, best known for controlling the collective polarization of cells across the plane of a cell sheet, a phenomenon referred to as PCP. It has been shown that the PCP pathway plays a central role in alveologenesis and adult lung homeostasis (Poobalasingam et al, 2017; Zhang et al, 2020) and is important for normal repair of the lung epithelium following injury (Poobalasingam et al, 2017) Both embryonic and adult PCP mouse mutants display abnormal actomyosin distribution (Yates et al, 2010b; Poobalasingam et al, 2017). We provide mechanistic evidence that VANGL2 disruption affects FA complexes, stress fiber formation, and MLC2 activation, leading to defective intracellular contractility via RhoA signaling These abnormalities result in impaired traction force generation and deficiency of the mechanotransducer YAP. This study demonstrates that VANGL2 has an important role in mechanosignaling, which underlies the key functions of PCP pathway in regulating tissue morphogenesis and repair

RESULTS

DISCUSSION

MATERIALS AND METHODS

ETHICS STATEMENT