Abstract: Objective To explore the role of annexin A1 (ANXA1) in resveratrol regulation of M2 type polarization of rat microglial cell line with oxygen glucose deprivation/reoxygenation (OGD/R) model. Methods Lentivirus LV-shAnxA1 was used to silence the expression of AnxA1 in N9 cells. LV-Scramble acted as a control lentivirus. Western blot and RT-qPCR were used to verify the efficiency of lentivirus infection. 3 d after lentivirus infection, the N9 cell OGD/R model was constructed. 3 days after reoxygenation, the cells were treated with resveratrol for 24 hours. The groups were as follows: OGD/R(-) group, OGD/R(+) group, OGD/R(+)+Res group, OGD/R(+)+Res+LV-Scramble group, OGD/R(+)+Res+LV-shAnxA1. RT-qPCR and Western blot were used to detect the mRNA and/or protein content of ANXA1, CD11b, tumor necrosis factor (TNF-α), Interleukin-1β(IL-1β), arginase-1 (Arg-1) and Interleukin-10 (IL-10). Immunofluorescence was applied to observe the distribution of ANXA1 in cells. Results The level of ANXA1 mRNA and protein in OGD/R(+)+Res group was significantly higher than that in OGD/R(+) group. The ANXA1 protein in the OGD/R(+) group was mainly distributed in the nucleus,while the ANXA1 protein in the OGD/R(+)+Res group was mainly distributed in cytoplasm. After inhibiting the expression of ANXA1, the OGD/R(+)+Res+LV-shAnxA1 group ANXA1 was mainly located in the nucleus. Compared with the OGD/R(+)+Res group, the CD11b protein content in the OGD/R(+)+Res+LV-shAnxA1 group was significantly increased (P＜0.01), and the TNF-α and IL-1β mRNA levels were significantly increased(P＜0.001), while Arg-1 and IL-10 mRNA levels were significantly reduced. Conclusions Resveratrol promotes the polarization of rat microglial cell line wih OGD/R model to M2 type via upregulation of ANXA1 expression.

Key words: resveratrol, ANXA1, oxygen glucose deprivation/reoxygenation(OGD/R), microglia, M2 polarization