title: The effects of TGF-β1 on the expression of type IV collagenases in mouse peritoneal macrophages.
abstract: Transforming growth factor-β (TGF-β) is a pleiotropic cytokine that plays a critical role in modulating immune response and inflammation. We have investigated the effects of TGF-β1 on the expression of type IV collagenases, matrix metalloproteinase (MMP)-2 and MMP-9, in mouse peritoneal macrophages. TGF-β1 alone enhanced the secretion of MMP-9, while it blocked lipopolysaccharide (LPS)-stimulated MMP-9 production. We have shown that this biphasic effect of TGF-β1 is exerted at the mRNA level of the MMP-9 gene. Although TGF-β1 increased both basal and LPS-induced MMP-2 production at the protein and mRNA levels, the extent of the increase was smaller in LPS-activated macrophages than in control macrophages. The expression of type I and type II receptors for TGF-β was significantly decreased upon activation, suggesting that the lesser effect of TGF-β1 in activated macrophages may result from the decreased expression of TGF-β receptors. In addition, the expression of endogenous TGF-β1 mRNA was decreased significantly in activated macrophages. These findings suggest that activated macrophages not only produce less TGF-β1, but also respond less well to TGF-β to provide for inflammatory response.
authors.affiliation: Laboratory of Cellular Biochemistry, RIKEN, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. kkogawa@riken.jp
authors.forename: Kenji
authors.initials: K
authors.lastname: Ogawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Funaba
authors.forename: Masafumi
authors.initials: M
authors.lastname: Tsujimoto
mesh_terms: D000818:Animals; D017364:Collagenases / Q000096:biosynthesis*; D005260:Female; D005786:Gene Expression Regulation; D008264:Macrophages / Q000166:cytology*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D010537:Peritoneum / Q000166:cytology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014018:Tissue Distribution; D053773:Transforming Growth Factor beta1 / Q000096:biosynthesis*
chemical_list: D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; D017364:Collagenases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9