Expression Of Pim-1and Related Regulating Signaling Pathways In LPS-induced Activated Macrophage

AIMS:The aims of this study were to explore the expression of Pim-1kinase during the activate progression of macrophage and to assess whether influence four key signaling molecules (PI3K,P38MAPK, MEK1/2, JAK2) may influence the expression of pim-1kinase.METHODS:Murine peritoneal macrophages were isolated、 cultured and then divided into seven groups, the expression of Pim-1mRNA and kinase in LPS stimulated macrophage cells with seven different time point(0h,lh,2h,4h,8h,12h,24h)were examined by real-time PCR and western blot respectively.Murine peritoneal macrophages were isolated、cultured and then divided into six groups,the six groups were stimulated by LPS,LPS+DMSO,LPS+LY294002(special inhibitor of PI3K),LPS+SB203580(special inhibitor of P38MAPK), LPS+AG490(special inhibitor of MEK1/2), LPS+U0126(special inhibitor of JAK2).The effects of special signaling inhibitors on LPS-induced up-regulation of Pim-1kinase were examined by western blot.RESULTS:①Expression of Pim-1was correlated with the treated time of lipopolysaccharides on macrophage in vitro, and Pim-1mRNA and kinase were rapidly induced after LPS treatment (1h);Pim-1mRNA reached the peak in2h,and was six-fold of the basic value, and fell back to foundational level in12h.②Pm-1kinase were on the constant rise during1h to8h, and drop to basic level in12h.③LY294002for PI3K、 SB203580for P38MAPK,AG490for MEK1/2,U0126forJAK2, reduced p-AKT,p-P38,p-ERK,p-JAK2level in macrophage respectively, and all of the four key signaling molecules inhibitors down-regulated LPS induced up-expression of Pim-1kinase.CONCLUSIONS:Up-regulation of Pim-1was an early event of classical activation of macrophage,Pim-1has important regulatory function for classically activated macrophage,and four signaling pathways,PI3K/AKT,P38MAPK, MEK/ERK and JAK2/STATs, functioned as positively regulators of expression of Pim-1kinase.