基于cGAS/STING通路探讨沙参麦冬汤含药血清延缓肺微血管内皮细胞炎性衰老的作用机制OA

Objective:To investigate the mechanism by which the drug-containing serum of Shashen Maidong Decoction improves D-galactose(D-gal)-induced inflammatory senescence in human pulmonary microvascular endothelial cells(HPMECs)via the cyclic guanosine monophosphate-adenosine monophosphate synthase(cGAS)/stimulus-triggered interferon gene(STING)signaling pathway.Methods:A D-gal-induced inflammatory senescence model in HPMECs was established.Using the MTT assay,HPMECs were treated with 5％and 10％drug-containing serum from the Shashen Maidong Decoction at low,medium,and high doses to screen for the optimal concentration of the drug-containing serum.Cells were divided into the control serum group,the model group,the model+optimal drug-containing serum group,and the model+dexamethasone group,with each group receiving the corresponding intervention.Senescence-associated β-galactosidase(SA-β-gal)staining was used to observe cell senescence;flow cytometry to detect cell cycle;ELISA to detect the expression levels of pro-inflammatory cytokines interleukin-6(IL-6),interleukin-8(IL-8),and monocyte chemotactic protein-1(MCP-1)in cell culture supernatants;Western blot to detect the expression of cellular senescence markers p53 and p21;and siRNA to silence STING gene in HPMECs.The study was divided into the following groups:control serum group,model group,STING siRNA group,model+STING siRNA group,model+drug-containing serum group,and model+STING siRNA+drug-containing serum group.Western blot analysis was performed to detect the expression of pathway proteins cGAS and STING,as well as senescence markers p53 and p21.Results:Compared with the blank serum group,the model group exhibited reduced cell proliferation activity,increased SA-β-gal positivity,an increased G0/G1 phase proportion,a decreased G2/M phase proportion,a decreased S phase proportion,upregulated IL-6,IL-8,and MCP-1,an increased expression of senescence proteins p21 and p53,and improved cell cycle arrest(decreased proportion of G0/G1 phase and increased proportion of S phase),(P＜0.05).Following STING silencing,compared with the STING siRNA group,the model+STING siRNA group exhibited increased expression of p21 and p53,increased expression of cGAS and STING proteins,and an increased SA-β-gal positivity rate;combined serum intervention reduced the expression of signaling pathway proteins and senescence-associated proteins,and decreased the SA-β-gal positivity rate(P＜0.05).Conclusion:Shashen Maidong Decoction can alleviate D-gal-induced cellular senescence and inflammatory responses in HPMECs,and its mechanism may be related to the regulation of the cGAS/STING signaling pathway.