地黄醇提物含药血清调控BV2小胶质细胞极化干预神经炎症的机制OA

OBJECTIVE To study the mechanism of action of Rehmannia glutinosa-medicated serum(RG)in regulating lipopolysaccharide(LPS)-induced polarization of BV2 microglia to interfere with neuroinflammation.METHODS An in vitro neuroinflammation model of BV2 cells induced by LPS was established.Cells were divided into control group,LPS group,10%RG group,20%RG group,BAY 11-7082[nuclear factor kappa B(NF-κB)inhibitor]group,and 20%RG+BAY 11-7082 group.Except for the control group,cells in all other groups were pretreated with corresponding drugs for 12 h and then stimulated with LPS for 24 h.The morphology of cells in each group was observed,and the fluorescence intensity of ionized calcium binding adaptor molecule 1(Iba-1),inducible nitric oxide synthase(iNOS),CD206,the mRNA expression of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6),IL-1β,iNOS,IL-4,IL-10,transforming growth factor-β(TGF-β),arginase-1(Arg-1),and the Toll-like receptor 4(TLR4)/NF-κB/NOD-like receptor thermal protein domain associated protein 3(NLRP3)signaling pathway-related protein expression were detected.RESULTS Compared with the control group,the LPS group showed significant changes in cell morphology,exhibiting a typical M1 activated morphology.The fluorescence intensity of Iba-1 and iNOS,the relative expression levels of TNF-α,IL-6,IL-1β,iNOS mRNA,the relative expression levels of TLR4,NLRP3,caspase-1 p20,IL-1β p17 protein,and the phosphorylation levels of NF-κB p65 and inhibitor of nuclear factor kappa B α were significantly increased(P＜0.05).The fluorescence intensity of CD206 and the relative expression levels of IL-4,IL-10,TGF-β,and Arg-1 mRNA were significantly reduced(P＜0.05).Compared with the LPS group,the changes in the above indicators in the cells of the 10%RG group,20%RG group,BAY 11-7082 group,and 20%RG+BAY 11-7082 group were significantly reversed(P＜0.05),and there was no statistically significant difference in the comparison of the last three groups(P＞0.05).CONCLUSIONS RG can effectively inhibit the overall activation of microglia and correct their M1/M2 polarization imbalance,and its mechanism may be closely related to the inhibition of excessive activation of the TLR4/NF-κB/NLRP3 signaling pathway.