OBJECTIVE: To investigate the expression of steroidogenic acute regulatory protein (StAR) in macrophages and the effects of inflammatory cytokines on StAR expression. METHODS: The macrophages isolated from ApoE knockout mice and C57BL/6J mice and RAW264.7 cells (a cell line from mouse macrophage. ATCC Number: TIB-71) were cultured in DMEM containing 10% fetal bovine serum. RAW264.7 cells were treated with different inflammatory cytokines (TNF-alpha, IFN-gamma and TGF-beta1) and 8-Br-cAMP, a cAMP analog. RT-PCR and Western blot analysis were applied to evaluate the effects of inflammatory cytokines on StAR expression. RESULTS: RT-PCR and Western blot analysis demonstrated the expression of StAR in the macrophages isolated from ApoE knockout mice, C57BL/6J mice and RAW264.7 cells. Proinflammatory cytokines TNF-alpha and IFN-gamma significantly decreased StAR mRNA and protein levels in RAW264.7 cells. The inhibition was dose- and time-dependent. In contrast, anti-inflammatory cytokine TGF-beta1 increased StAR mRNA and protein levels. At 1:15 molecular ratio, TGF-beta1 blocked the down-regulation of StAR expression mediated by TNF-alpha. cAMP also induced StAR expression in RAW264.7 cells. When the cells were co-treated with 8-Br-cAMP and TNF-alpha, 8-Br-cAMP failed to induce StAR expression. CONCLUSION: Our results provide interesting evidence that inflammatory cytokines regulate StAR expression in macrophages.
OBJECTIVE: To investigate the expression of steroidogenic acute regulatory protein (StAR) in macrophages and the effects of inflammatory cytokines on StAR expression. METHODS: The macrophages isolated from ApoE knockout mice and C57BL/6J mice and RAW264.7 cells (a cell line from mouse macrophage. ATCC Number: TIB-71) were cultured in DMEM containing 10% fetal bovine serum. RAW264.7 cells were treated with different inflammatory cytokines (TNF-alpha, IFN-gamma and TGF-beta1) and 8-Br-cAMP, a cAMP analog. RT-PCR and Western blot analysis were applied to evaluate the effects of inflammatory cytokines on StAR expression. RESULTS: RT-PCR and Western blot analysis demonstrated the expression of StAR in the macrophages isolated from ApoE knockout mice, C57BL/6J mice and RAW264.7 cells. Proinflammatory cytokines TNF-alpha and IFN-gamma significantly decreased StAR mRNA and protein levels in RAW264.7 cells. The inhibition was dose- and time-dependent. In contrast, anti-inflammatory cytokine TGF-beta1 increased StAR mRNA and protein levels. At 1:15 molecular ratio, TGF-beta1 blocked the down-regulation of StAR expression mediated by TNF-alpha. cAMP also induced StAR expression in RAW264.7 cells. When the cells were co-treated with 8-Br-cAMP and TNF-alpha, 8-Br-cAMP failed to induce StAR expression. CONCLUSION: Our results provide interesting evidence that inflammatory cytokines regulate StAR expression in macrophages.
Authors: Witold Korytowski; Katarzyna Wawak; Pawel Pabisz; Jared C Schmitt; Alexandra C Chadwick; Daisy Sahoo; Albert W Girotti Journal: Arterioscler Thromb Vasc Biol Date: 2015-08-27 Impact factor: 8.311
Authors: Ben Gibbison; Francesca Spiga; Jamie J Walker; Georgina M Russell; Kirsty Stevenson; Yvonne Kershaw; Zidong Zhao; David Henley; Gianni D Angelini; Stafford L Lightman Journal: Crit Care Med Date: 2015-04 Impact factor: 7.598