Regulation of TXB(2) and PGE(2) production by TGF-β(1) in in vitro silica dust-exposed rat alveolar macrophage

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