Regulation of TXB₂ and PGE₂ production by TGF-β₁ in in vitro silica dust-exposed rat alveolar macrophage

Abstract

We investigated the effect of transforming factor factor-β₁ (TGF-β₁) on thromboxane B₂ (TXB₂) and prostaglandin E₂ (PGE₂) production in in vitro silica dust-exposed rat alveolar macrophages (AM). In the presence of 5 μg of anti-TGF-β₁ antibodies, TXB₂ production decreased, but PGE₂ production increased. Addition of 2 ng of TGF-β₁ to the culture medium potentiated TXB₂ production, but PGE₂ production apparently did not change. At 50 ng of TGF-β₁, TXB₂ production decreased, and PGE₂ production varied. Our data suggest that in rat AM: (1) both endogenous and exogenous TGF-β₁ regulate TXB₂ production; and (2) in the absence of endogenous TGF-β₁ the liberation of PGE₂ increases; however, exogenous TGF-β₁ does not have a regulatory effect on PGE₂.