Airway Smooth Muscle Cells Dynamically Change Their Intercellular Coupling During Agonist Exposure
Year: 2021
Type: conference-abstract
Abstract: Introduction: For airways to constrict, the smooth muscle cells (SMCs) must form a connected path that transmits force around the circumference of the airway lumen. The number of cells that form this connected path and the inter-cellular coupling strength will dictate how smooth muscle force is translated into changes in luminal area of an airway. Additionally, the extracellular matrix (ECM) stiffness can alter the force transmission pathway among cells between cell-cell adherens junctions (AJs) and cell-matrix focal adhesions (FAs) 1,2 (Fig1A). Connectivity between SMCs is typically investigated using histology or immunostained cell cultures, but these techniques do not reveal the dynamics of cell-cell connectivity In this study, we measured how intercellular coupling among SMCs change during an airway constriction on soft and stiff ECM. Methods: Primary airway SMCs from healthy human donors (passage3-7) were grown to confluence on collagen-coated silicone substrates with Young's modulus of E=0.3kPa (soft matrix) or E=13kPa (stiff matrix) (Fig1B). The surface of the substrates was coated with fluorescent microspheres for displacement tracking prior to cell culture. After serum starvation, the cells and microspheres were imaged with a 20x objective at 1Hz for 1 minute at baseline followed by 10 -5 M histamine addition and 5 more minutes of imaging. We calculated traction stresses exerted on the matrix by the cells and stresses within the cell monolayer using monolayer stress microscopy algorithm 3 (Fig1C). To quantify intercellular coupling, we calculated a dimensionless ratio, , that varies from 0 to 1 and is defined as the fraction of the total contractile moment that an SMC exerts on its neighboring cells through AJs. As 1, the cell's force is transmitted to its neighbors entirely through AJs. As 0, the cell's force is transmitted entirely through FAs. This value is calculated for each cell over time (Fig1D). Results: After exposure to contractile agonist, the direct intercellular coupling between SMCs on stiff matrix decreased, and cells exerted more of their contractile force through cellmatrix connections. The mechanical coupling between cells on soft matrix was not affected by agonist exposure. Conclusion: ECM stiffness can alter the agonistresponse of airway SMCs by changing the intercellular connectivity and rerouting force transmission as they constrict.
Authors: S.E. Stasiak, D.T. Tambe, H. Parameswaran
Institutions: Northeastern University, University of South Alabama
Language: English
Subfield: Cell Biology
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W4253971398