Chemerin/ChemR23 promotes high glucose-induced IL-6 and TNF-α expressions in glomerular endothelial cells via p38 MAPK / 中华肾脏病杂志

ABSTRACT

Objective To observe the role and related mechanism of chemerin and its receptor ChemR23 in glomerular endothelial cells (GEnCs) stimulated by high glucose.Methods Mouse GEnCs were cultured and divided into control group,20.0 mmol/L high glucose group,40.0 mmol/L high glucose group and mannitol control group.Then the expressions of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in cell culture supematant as well as the expressions of intracellular protein and mRNA of chemerin,ChemR23,IL-6 and TNF-α were detected.Lentiviral transfection targeting ChemR23 was applied before high glucose-or Chemerin-stimulated,and expressions of supernatant and intracellular mRNA of IL-6 and TNF-α were measured.Meanwhile whether p38 mitogen-activated protein kinase (p38 MAPK) pathway was activated by high glucose was detected.The specific inhibitor of p38 MAPK was added prior to high glucose-stimulated,then supernatant and intracellular mRNA expressions of IL-6 and TNF-α was detected.The supernatant expressions of IL-6 and TNF-α were measured by ELISA.The intracellular protein expression and p38 MAPK phosphorylation activity were detected by Western blotting.The mRNA expression was detected by real time PCR.Results Compared with those in the control group,in high glucose groups the expressions of IL-6,TNF-α and chemerin were significantly increased (all P ＜ 0.05),however,the expressions of ChemR23 did not change (all P ＞ 0.05);the supernatant and mRNA expressions of IL-6 and TNF-α were also elevated in the chemerin group (all P ＜ 0.05).Lentivirus baring shRNA could efficiently suppress ChemR23 expression,and the Chemerin-or high glucose-induced expressions of IL-6 and TNF-α were reduced (all P ＜ 0.05).Also it could significantly reduce the expression of phosphorylated-p38 MAPK (p-p38 MAPK) induced by high glucose (P ＜ 0.05),as high glucose group had higher p-p38 MAPK than control group (P ＜ 0.05).While the high glucose-elevated expressions of IL-6 and TNF-α were significantly attenuated by p38 MAPK inhibitor (all P ＜ 0.05).Conclusions High glucose stimulation can induce the expression of chemerin in GEnCs.By binding to ChemR23,chemerin activates p38 MAPK signaling pathway,and then promotes the expressions of IL-6 and TNF-α.These inflammatory cytokines aggravate inflammation of GEnCs.