西格列汀激活基质细胞衍生因子-1/CXC趋化因子受体4信号通路对脂多糖诱导的人牙周膜干细胞增殖、凋亡、炎症和成骨分化的影响OA北大核心CSTPCD

Objective This study aimed to investigate the effects of sitagliptin on the proliferation,apoptosis,in-flammation,and osteogenic differentiation of human periodontal ligament stem cells(hPDLSCs)in lipopolysaccharide(LPS)-induced inflammatory microenvironment and its molecular mechanism.Methods hPDLSCs were cultured in vitro and treated with different concentrations of sitagliptin to detect cell viability and subsequently determine the exper-imental concentration of sitagliptin.An hPDLSCs inflammation model was established after 24 h of stimulation with 1 µg/mL LPS and divided into blank,control,low-concentration sitagliptin(0.5 µmol/L),medium-concentration sita-gliptin(1 µmol/L),and high-concentration sitagliptin(2 µmol/L),high-concentrationsitagliptin+stromal cell derived factor-1(SDF-1)/CXC chemokine receptor 4(CXCR4)pathway inhibitor(AMD3100)(2 µmol/L+10 µg/mL)groups.A cell-counting kit-8 was used to detect the proliferation activity of hPDLSCs after 24,48,and 72 h culture.The apoptosis of hPDLSCs cultured for 72 h was detected by flow cytometry.After inducing osteogenic differentiation for 21 days,alizarin red staining was used to detect the osteogenic differentiation ability of hPDLSCs.The alkaline phosphatase(ALP)activity in hPDLSCs was determined using a kit.The levels of inflammatory factors[tumor necrosis factor(TNF)-α,interleukin(IL)-1β,and IL-6]in the supernatant of hPDLSCs culture were detected by enzyme-linked immu-nosorbent assay.The mRNA expressions of osteogenic differentiation genes[Runt-associated transcription factor 2(RUNX2),osteocalcin(OCN),osteopontin(OPN)],SDF-1 and CXCR4 in hPDLSCs were detected by real-time fluores-cence quantitative polymerase chain reaction(RT-qPCR).Western blot analysis was used to determine SDF-1 and CX-CR4 protein expression in hPDLSCs.Results Compared with the blank group,the proliferative activity,number of mineralized nodules,staining intensity,ALP activity,and RUNX2,OCN,OPN mRNA,SDF-1,and CXCR4 mRNA and protein expression levels of hPDLSCs in the control group significantly decreased.The apoptosis rate and levels of TNF-α,IL-1β,and IL-6 significantly increased(P<0.05).Compared with the control group,the proliferative activity,number of mineralized nodule,staining intensity,ALP activity,and RUNX2,OCN,OPN mRNA,SDF-1,and CXCR4 mRNA and protein expression levels of hPDLSCs in low-,medium-,and high-concentration sitagliptin groups in-creased.The apoptosis rate and levels of TNF-α,IL-1β,and IL-6 decreased(P<0.05).AMD3100 partially reversed the effect of high-concentration sitagliptin on LPS-induced hPDLSCs(P<0.05).Conclusion Sitagliptin may promote the proliferation and osteogenic differentiation of hPDLSCs in LPS-induced inflammatory microenvironment by activating the SDF-1/CXCR4 signaling pathway.Furthermore,it inhibited the apoptosis and inflammatory response of hPDLSCs.