Investigation On The Function Of NLRP3 Signal Pathway In Periodontitis In Different Inflammation Status

1.BackgroundChronic inflammation is a common pathological mechanism of series of chronic diseases such as obesity and diabetes.Individuals with obesity are characterized by long-term low level chronic systemic inflammation,abnormal immune response,insulin resistance,which make them susceptible to metabolic diseases like diabetes,etc.Obesity is an important pathogenesis of diabetes.Obesity and diabetes are twin epidemics,and can both aggravate periodontitis.However,the involved mechanism via NLRP3 pathway is still to be illuminated.The purpose of this study is to explore the impact of systemic inflammation status caused by obesity and type 2 diabetes on the periodontal tissues,and the the involved mechanism via NLRP3 pathway.2.Methods(1)Diet-induced obesity model(DIO)was constructed by high-fat diet for 16w and periodontal ligation for 10d.It included normal diet without periodontitis(NC),normal diet with periodontitis(NP),high-fat diet without periodontitis(HFC),high-fat diet with periodontitis(HFP).Record the body-weight in 0w-16w weekly and blood glucose level in 0w,16w.Collect the maxilla for Micro CT detection in order to analyze alveolar bone resorption.Collect the serum for ELISA and MSD detection in order to analyze the systemic inflammation status.(2)RT-PCR and IHC were applied to investigate the NLRP3 signal pathway(NLRP3,capase1,IL-1?,NF?b)and F4/80,MCP1 in mouse gingival tissues.(3)BMDMs under different diet background(NC/HFC)were derived and stimulated by LPS,which included NC,NC+LPS,HFC,HFC+LPS.RT-PCR and ICC were applied to investigate the NLRP3 signal pathway.(4)Collect the human gingival tissues which included control(C),chronic periodontitis(CP)and chronic periodontitis with type 2 diebetes(CP+DM).RT-PCR and IHC were applied to investigate the NLRP3 signal pathway(NLRP3,capasel,IL-1?,NF?b).HGECs were derived and stimulated by high glucose(HG)and LPS,which included C,C+LPS,HG,HG+LPS.RT-PCR and ICC were applied to investigate the NLRP3 signal pathway.3.Results(1)The body-weight and blood glucose level in HFD are significantly higher than ND after DIO 16w.The alveolar bone resorption detected by Micro CT:NP>NC and HFP>HFC(P<0.05),HFP>NP(P<0.05).The insulin and TNF-?,IL-1?,IL-6,IL-10 level in serum:HFC>NC(P<0.05).(2)The NLRP3 signal pathway expressions in mouse gingival tissues:NP>NC and HFP>HFC(P<0.05),HFC<NC and HFP<NP(P>0.05).(3)The F4/80 and MCP1 expressions in mouse gingival tissues:NP>NC and HFP>HFC(P<0.05),HFC<NC and HFP<NP(P<0.05).The NLRP3 signal pathway expressions in mouse BMDMs:NC+LPS>NC,HFC+LPS>HFC(P<0.05);HFC<NC,HFC+LPS<NC+LPS(P<0.05).(4)The NLRP3 signal pathway(NLRP3,capasel,IL-1?,NF?b)expressions in human gingival tissues:CP>C(P<0.05)and CP+DM>CP(P>0.05).The NLRP3 signal pathway(NLRP3,capasel,IL-1?,NF?b)in HGECs:HG>C and HG+LPS>C+LPS(P<0.05).4.ConlusionThe chronic inflammation status of obesity and type 2 diabetes aggravate periodontitis.The link between obesity and periodontitis could be obesity increases expression of inflammatory mediator(such as insulin and TNF-?,IL-1?,IL-6,IL-10 level in serum),which increase the susceptibility of periodontitis.The link also could be obesity decreases the number and activity of macrophages in periodontal tissues with inflammation,which leads to the abnormal innate immunity of periodontium.The link between type 2 diabetes and chronic periodontitis could be the high expression of NLRP3 signal pathway in gingival epithelial cells under high glucose status,with aggravates periodontitis.