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Study of the insulin signaling pathways in the regulation of ACAT1 expression in cultured macrophages
Author(s) -
Xin Chen,
YanFu Wang,
Ping He,
Jing Ge,
JingJing Wan,
ChunLi Mei,
Wei Liu,
Bei Cheng
Publication year - 2009
Publication title -
cell biology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 77
eISSN - 1095-8355
pISSN - 1065-6995
DOI - 10.1016/j.cellbi.2009.02.011
Subject(s) - wortmannin , mapk/erk pathway , signal transduction , phosphatidylinositol , kinase , microbiology and biotechnology , protein kinase c , phospholipase c , p38 mitogen activated protein kinases , biology , mitogen activated protein kinase , protein kinase a , chemistry
Objective : To determine the signaling pathways and components involved in insulin‐mediated regulation of Acyl‐CoA: cholesterol acyltransferase1 (ACAT1). Methods : THP‐1 cells were cultured in RPMI 1640 medium and were induced into macrophages in the presence of 160 nM phorbol 12‐myristate 13‐acetate (PMA). Before insulin was added in, macrophages were preincubated with the inhibitors of the insulin signaling pathway, including wortmannin, phosphatidylinositol 3‐kinase (PI3 K) inhibitor; PD98059, extracellular signal‐regulated kinase (ERK) inhibitor; SB203580, p38 mitogen‐activated protein kinase (p38MAPK) inhibitor; SP600125, c‐Jun N‐terminal kinase (JNK) inhibitor and U73122, phospholipase C‐γ (PLC‐γ) inhibitor. ACAT1 mRNA and protein expression level in macrophages were determined by real‐time quantitative polymerase chain reaction and western blotting, respectively. Results : Real‐time quantitative polymerase chain reaction and western blotting demonstrated that PD98059, SB203580 or SP600125 down‐regulated the expression of ACAT1 in a dose‐dependent manner. However, no obvious alteration was found in wortmannin and U73122 groups. Conclusion : These results suggest that the ERK, p38MAPK and JNK signaling pathways may be involved in insulin‐mediated regulation of ACAT1, but no PI3K and PLC‐γ signaling pathways were involved in the present study.