AJP - Lung Cellular and Molecular Physiology, Vol 267, Issue 5 569-L577, Copyright © 1994 by American Physiological Society
Transforming growth factor-beta 1 modulates type II cell fibronectin and surfactant protein C expression
W. M. Maniscalco, R. A. Sinkin, R. H. Watkins and M. H. Campbell
Department of Pediatrics, Strong Children's Research Center, University of Rochester, New York 14642.
Extracellular matrix (ECM) deposition by alveolar type II cells is
important for repair of a damaged alveolar epithelium. Transforming growth
factor-beta (TGF-beta) is abundant in injured lung and has profound effects
on ECM production and cell differentiation. We determined the effects of
TGF-beta 1 on type II cell expression of fibronectin and surfactant protein
C (SP-C) in vitro. TGF-beta 1 increased the proportion of type II cells
with detectable mRNA for fibronectin from 9 to 68%, as demonstrated by in
situ hybridization, and increased the fibronectin mRNA levels 10-fold.
TGF-beta 1-treated cultures had increased immunostaining for fibronectin
and increased secretion of metabolically labeled fibronectin. A decreased
proportion of type II cells treated with TGF-beta 1 had detectable mRNA for
SP-C, and the abundance of this message per cell decreased to 25% of
control values. No effects of TGF-beta 1 were noted on the proportion of
cells that contained lamellar bodies, which was 87% in both groups. These
data indicate that TGF-beta 1 regulates type II cell fibronectin protein an
mRNA levels. In addition, the decreased abundance of SP-C mRNA suggests
that TGF-beta 1 may also modulate type II cell differentiation in lung
injury.
