Age-Dependent Expression of Collagen Receptors and Deformation of Type I Collagen Substrates by Rat Cardiac Fibroblasts

Christopher G. Wilson, University of South Carolina - Columbia
John W. Stone, Georgia Southern University
Vennece Fowlkes, University of South Carolina - Columbia
Mary O. Morales, University of South Carolina - Columbia
Catherine J. Murphy, University of Illinois at Urbana-Champaign
Sarah C. Baxter, University of South Carolina - Columbia
Edie C. Goldsmith, University of South Carolina - Columbia

This is an Accepted Author Manuscript obtained from PMC. The publisher's final edited version of this article is available at Microscopy and Microanalysis.

Abstract

Little is known about how age influences the ways in which cardiac fibroblasts interact with the extracellular matrix. We investigated the deformation of collagen substrates by neonatal and adult rat cardiac fibroblasts in monolayer and three-dimensional (3D) cultures, and quantified the expression of three collagen receptors [discoidin domain receptor (DDR)1, DDR2, and β1 integrin] and the contractile protein alpha smooth muscle actin (α-SMA) in these cells. We report that adult fibroblasts contracted 3D collagen substrates significantly less than their neonate counterparts, whereas no differences were observed in monolayer cultures. Adult cells had lower expression of β1 integrin and α-SMA than neonate cultures, and we detected significant correlations between the expression of α-SMA and each of the collagen receptors in neonate cells but not in adult cells. Consistent with recent work demonstrating age-dependent interactions with myocytes, our results indicate that interactions between cardiac fibroblasts and the extracellular matrix change with age.