Am J Physiol Lung Cell Mol Physiol

. 2021 Dec 1. doi: 10.1152/ajplung.00310.2020. Online ahead of print. https://pubmed.ncbi.nlm.nih.gov/34851724/

Mouse Lung Organoid Responses to Reduced, Increased, and Cyclic Stretch

Rashika Joshi ¹, Matthew R Batie ², Qiang Fan ¹, Brian Michael Varisco ^1 3Affiliations expand

• PMID: 34851724
• DOI: 10.1152/ajplung.00310.2020

Abstract

Most lung development occurs in the context of cyclic stretch. Alteration of the mechanical microenvironment is a common feature of many pulmonary diseases with congenital diaphragmatic hernia (CDH) and fetal tracheal occlusion (FETO, a therapy for CDH) being extreme examples with changes in lung structure, cell differentiation and function. To address limitations in cell culture and in vivo mechanotransductive models we developed two mouse lung organoid (mLO) mechanotransductive models using postnatal day 5 (PND5) mouse lung CD326-positive cells and fibroblasts subjected to increased, decreased, and cyclic strain. In the first model, mLOs were exposed to forskolin (FSK) and/or disrupted (DIS) and evaluated at 20 hours. mLO cross-sectional area changed by +59%, +24% and -68% in FSK, control, and DIS mLOs respectively. FSK-treated organoids had twice as many proliferating cells as other organoids. In the second model, 20 hours of 10.25% biaxial cyclic strain increased the mRNAs of lung mesenchymal cell lineages compared to static stretch and no stretch. Cyclic stretch increased TGF-β and integrin-mediated signaling with upstream analysis indicating roles for histone deacetylases, microRNAs, and long non-coding RNAs. Cyclic stretch mLOs increased αSMA- and αSMA-PDGFRα-double positive cells compared to no stretch and static stretch mLOs. In this PND5 mLO mechanotransductive model, cell proliferation is increased by static stretch, and cyclic stretch induces mesenchymal gene expression changes important in postnatal lung development.

Keywords: Lung Development; Lung Mesenchyme; Mechanotransduction.