Am. J. Respir. Cell Mol. Biol., Vol 12, No. 3, Mar 1995, 287-295.
Retinoic acid inhibition of transforming growth factor-beta-induced collagen production by human lung fibroblasts
CA Redlich, HM Delisser and JA Elias
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06510-8057.
Transforming growth factor-beta (TGF-beta)-stimulated collagen production
plays an important role in the pathogenesis of the fibrotic response seen
in chronic inflammatory lung disorders. Retinoids are vitamin A analogues
that are potent immunomodulators and have been shown to modulate stromal
cell collagen production in a variety of nonpulmonary systems. We
hypothesized that retinoids might also modulate lung fibroblast collagen
production. To test this hypothesis, we determined whether all-trans
retinoic acid (RA) and several other retinoid compounds regulate the
production of types I and III collagen by unstimulated and TGF-beta
1-stimulated human lung fibroblasts. Unstimulated cells produced modest
quantities of types I and III collagen, and TGF-beta 1 increased the
production of these matrix molecules 2- to 4-fold. Preincubation with
10(-5) M RA caused a significant decrease in the basal levels of types I
and III collagen produced by these cells. RA preincubation also totally
abrogated the collagen inductive effects of TGF-beta 1. At 10(-5) M, RA
preincubation caused a 97% decrease in the stimulation of type I collagen
and a 115% decrease in the stimulation of type III collagen caused by
TGF-beta 1. These inhibitory effects were dose dependent. Significant
inhibition of type I and III collagen production was appreciated with doses
of RA as low as 10(-9) and 10(-8), respectively. These inhibitory effects
were not unique to RA since 13-cis-retinoic acid, 9-cis-retinoic acid,
etretinate, all-trans etretin, and the water-soluble retinoids, retinoyl
beta-glucuronide and retinyl-beta-glucuronide, also inhibited TGF-beta
1-stimulated type I collagen production.(ABSTRACT TRUNCATED AT 250 WORDS)