Regulation of PU.1 on apoptosis resistance of aging macrophages stimulated by Porphyromonas gingivalis lipopolysaccharide

FANG Hui; YUAN Yiting; ZHANG Yongchun; REN Shanshan; CHEN Lulu; LIAO Wei; TIAN Ai

doi:10.3969/j.issn.1006-5725.2025.04.003

Abstract：Objective To investigate the regulatory effect of PU.1 on apoptosis resistance of aging macro-phages under in vitro inflammatory stimulation simulated by lipopolysaccharide(LPS)of Porphyromonas.Methods The expression of PU.1 in periodontitis gingival tissue and normal gingival tissue was analyzed by GEO database.Mouse macrophage cell line RAW264.7 was divided into control group,P.g-LPS group,H2O2 group and PU.1 inhibitor group.mRNA expression of senescence associated secretory phenotype(IL-6,IL-1β,TNF-α)and PU.1 were detected by RT-qPCR;The protein expressions of p21,p16,BAX,caspase-3,Bcl-2,Bcl-xl and PU.1 were detected by Western blot.The number of senescent cells was detected by senescence-associated-galactosidase(SA-β-gal)staining.The apoptosis rate was detected by flow cytometry.Results Compared with control group,the expression of p21,p16 protein and mRNA of IL-6,IL-1β and TNF-α were up-regulated in P.g-LPS group and H2O2 group,the number of senescent cells was increased,the expression of Bcl-2 and Bcl-xl was up-regulated,the expression of BAX and caspase-3 was decreased,and the apoptosis rate was decreased.Meanwhile,the mRNA and protein expression of PU.1 were increased(P<0.05).Compared with P.g-LPS group,mRNA and protein expression of PU.1 in PU.1 inhibitor group were down-regulated,Bcl-2 and Bcl-xl were down-regulated,BAX and caspase-3 expressions were increased,apoptosis rate was increased,the number of senescent cells was decreased,and mRNA levels of IL-6,IL-1β and TNF-α were decreased.The expression of p21 and p16 proteins were down-regulated.(P<0.05).Conclusion Under inflammatory stimulation in vitro,increased expression of PU.1 induced apoptosis resistance of aging macrophages,inhibition of PU.1 promoted apoptosis of aging macrophages,reduced the number of aging macrophages,and down-regulated the secretion of inflammatory factors.