Inhibition of NLRP3 inflammasome activation improves PCOS granulosa cell apoptosis by regulating autophagy
Objective:To investigate the expression of NOD-like receptor protein 3(NLRP3)inflammasome and its relation-ship with granulosa cell apoptosis in patients with polycystic ovary syndrome(PCOS).Methods:Follicular fluid and ovarian granulosa cells were collected from 17 PCOS patients(PCOS group)and 20 non-PCOS patients(control group),and the expression levels of pro-inflammatory factor,TNF-α,IL-1β and IL-18 in follicular fluid were detected by ELISA.RT-PCR and Western blot were used to de-tect NLRP3 mRNA and NLRP3 inflammasome associated protein NLRP3,ASC and cleaved caspase-1 and autophagy related protein LC3-Ⅱ/LC3-Ⅰ and p62 expression level in granulosa cells.TUNEL assay was used to detect the apoptotic level of granulosa cells in both groups.NLRP3 silenced siRNA(si-NLRP3)and negative control sequence(si-NC)were transfected into human ovarian cancer granulosa cell line KGN cells by siRNA interference technique in vitro.TNF-α was used to simulate PCOS-related cell damage.KGN cells were divided into 4 groups according to different treatment methods:Ctrl group,TNF-α group,TNF-α+si-NLRP3 group and TNF-α+si-NC group.The levels of DHEA,testosterone,IL-1β and IL-18 in supernatant were detected by ELISA.TUNEL assay was used to detect the apoptosis level of KGN cells.The LC3-Ⅱ/LC3-Ⅰ and p62,NLRP3,ASC and cleaved caspase-1 protein expression levels,and NF-κB p-p65 level(NF-κB p-p65/NF-κB p65)in KGN cells were detected by Western blot.Results:Compared with con-trol group,the concentration of TNF-α,IL-1β,and IL-18 in follicular fluid of PCOS patients,and LC3-Ⅱ/LC3-Ⅰ,NLRP3 mRNA and the protein expression of NLRP3,ASC,and cleaved caspase-1 in granulosa cells of and apoptosis were significantly increased(P<0.05 or P<0.01),while the protein expression of p62 was significantly decreased(P<0.01).Compared with Ctrl group,the levels of DHEA,testosterone,IL-1β and IL-18 in supernatant of TNF-α group,TNF-α+si-NC group,and TNF-α+si-NLRP3 group,and LC3-Ⅱ/LC3-Ⅰ,ASC and cleaved caspase-1 protein expression,and the level of NF-κB p-p65 and apoptosis were significantly increased(P<0.05 or P<0.01),while p62 protein was significantly decreased(P<0.01).NLRP3 was significantly decreased except in TNF-α+si-NLRP3 group(P<0.01),while in the TNF-α group and TNF-α+si-NC group was significantly increased(P<0.01).However,com-pared with TNF-α group,the above indexes in TNF-α+si-NLRP3 group were significantly decreased(P<0.05),and TNF-α+si-NC group had no significant change(P>0.05).Conclusion:The over-activated NLRP3 inflammasome in granulosa cells may promote cell inflammatory injury and autophagy apoptosis in PCOS patients through NF-κB pathway.
Polycystic ovary syndromeNod-like receptor protein 3(NLRP3)inflammasomeGranulosa cellsAutophagyApoptosis