| Objective: To investigate the effect of cobalt chloride or LPS and its mechanism on HIF-1αand TGF-β1 expression in macrophages Raw 264.7 .Methods: Macrophages Raw 264.7 were divided into four groups: group 1 was incubated with LPS(1μg/ml), group 2 incubated with CoCl2(100μmol/L), group 3 with CoCl2(100μmol/L)followed by culture with LPS(1μg/ml),and control group with PBS. The mRNA expression of HIF-1α, VEGF and TGF-β1 in the cells was measured by RT-PCR.The protein expression of both HIF-1α, VEGF and TGF-β1 was detected by immunocytochemistry.Results: (1)Compared with the control group, the expression levels of HIF-1αmRNA of group 2 and group 3 were elevated while the expression levels of VEGF mRNA and protein,HIF-1αprotein of the 1st,2nd and 3rd groups were higher. In contrast to 1st group,2nd group,s expression level of HIF-1αmRNA was obvious higher while the levels of HIF-1αor VEGF mRNA and protein of 3rd group was significantly higher.Compare to 2nd group,s,the 3rd group,s those of VEGF mRNA and protein,HIF-1αprotein were up-regulated .(2) Compared with control group, the 1st group,s expression levels of TGF-β1 mRNA and protein were obvious lower while the 2nd group,s expression levels were significantly higher,but the 3rd group,s expression level was not altered.Conclusions:In normoxic environment, LPS could down-regulate the expression level of TGF-β1 of macrophages Raw 264.7 by transcription mechanism.Hypoxia induced by CoCl2 could increase the expression levels of HIF-1α,VEGF and TGF-β1 mRNA or protein.LPS in the state of intracellular hypoxia can significantly increase the expression levels of HIF-1αand VEGF mRNA or protein while the expression levels of TGF-β1 mRNA and protein were not altered. These data indicate that the response of macrophages Raw 264.7 to stimulation of LPS varies with intracellular normoxia or hypoxia state, and the differences may have influence on the development and progression of related diseases.
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