Stromal interaction molecule 1 promotes microglia/macrophages M1 activation through endoplasmic reticulum stress after cerebral ischemia-reperfusion / 中华神经医学杂志

ABSTRACT

Objective:To investigate the influence and mechanism of stromal interaction molecule 1 (STIM1) in microglia/macrophages M1 activation after cerebral ischemia-reperfusion injury.Methods:(1) Animal experiment: 20 male C57BL/6J mice were randomly divided into sham-operated (Sham) group, middle cerebral artery occlusion and reperfusion (MCAO/R) group, MCAO/R+si-Ctrl group, and MCAO/R+si-STIM1 group ( n=5); MCAO/R models were established in mice of the latter 3 groups; empty vector control virus and STIM1 gene knockout lentivirus were transfected into mice in the MCAO/R+si-Ctrl group and MCAO/R+si-STIM1 group. The transfection efficiency of STIM1 and the expression of microglia/macrophages M1 activation marker cluster of differentiation 86 (CD86) in each group were observed. (2) Cell experiment: primary microglia were divided into Ctrl group, oxygen-glucose deprivation/re-oxygenation (OGD/R) group, OGD/R+si-Ctrl group, OGD/R+si-STIM1 group, OGD/R+solvent group, and OGD/R+4-phenylbutyric acid (4-PBA) group; OGD/R models were established in the later 5 groups; empty vector control virus and STIM1 gene knockout lentivirus were transfected into mice in the OGD/R+si-Ctrl group and OGD/R+si-STIM1 group; cells in the OGD/R+4-PBA group were pre-treated with 1 mmol/L 4-PBA for 1 h at 24 h before OGD/R modelling to inhibit endoplasmic reticulum stress (ERS), and cells in the OGD/R+solvent group were pre-treated with 0.5% dimethyl sulfoxide (DMSO) for 1 h at the same time. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), ELISA, Western blotting and other methods were used to detect the levels of CD86, tumour necrosis factor-α ( TNF-α) mRNA, interleukin (IL)-1β, and ERS-related proteins (transcription factor C/EBP homologous protein [CHOP], activated transcription factor 4 [ATF4]) in these cells. Results:(1) Animal experiment: the STIM1 expression in MCAO/R+si-STIM1 group was significantly lower than that in Sham group, MACO/R group and MCAO/R+si-Ctrl group ( P<0.05); as compared with that in the MACO/R group and MCAO/R+si-Ctrl group, the number of microglia/macrophages co-expressing CD86 and Iba-1 around the ischemic foci of mice in the MCAO/R+si-STIM1 group was significantly decreased ( P<0.05). (2) Cell experiment: as compared with those in the OGD/R group and OGD/R+si-Ctrl group, the expression levels of STIM1, CD86, and TNF-α mRNA, and supernatant IL-1β content in the OGD/R+si-STIM1 group were significantly decreased ( P<0.05); as compared with those in the OGD/R group and OGD/R+si-CTRL group, the ATF4 and CHOP expression levels in OGD/R+si-STIM1 group were significantly decreased ( P<0.05); as compared with those in the OGD/R group and OGD/R+solvent group, the CD86 level, TNF-α mRNA expression level and IL-1β content in the OGD/R+4-PBA group were significantly decreased ( P<0.05). Conclusion:STIM1 affects microglia/macrophages M1 activation after ischemia-reperfusion injury by regulating ERS level.