Environmental Pollutants Polychlorinated Biphenyls And Perfluorooctane Sulfonate Activate ROS-NLRP3 Inflammasome Pathway In Islet ?-Cells

Objective: Diabetes is the second largest chronic non-communicable disease,and its acute and chronic complications seriously affect the quality of life and lifetime of patients,but the pathogenesis of diabetes is still not clear.Studies show that diabetes is a clinical syndrome caused by genetic and environmental factors and related to environmental pollution.Growing evidences show environmental pollution is closely related to the pathogenesis of diabetes.Polychlorinated biphenyls(PCBs)and perfluorooctane sulfonate(PFOS)are persistent organic pollutants(POPs)and have bioaccumulation,persistent residuals,high toxicity and long distance migration,studies found that they can be detected in the human body,animals and the environment from the world,and they are closely related to the incidence and development with a variety of diseases such as diabetes,thyroid disease,autoimmune diseases,tumors etc.,but PCBs and PFOS can lead to the incidence of diabetes and the specific mechanism are still unknown currently.The central part of the incidence of diabetes is the occurrence of long-term low-level inflammatory response,and the innate immune-mediated inflammatory response is an important part,NLRP3 inflammasome is a member of the innate immune system,activated by intracellular and extracellular signaling molecules through a variety of ways,such as the production of reactive oxygen species(ROS),result in the activation of Caspase-1,promote the production of inflammatory factors.Studies have found that high concentrations of environmental pollutants,such as PCBs,PFOS,dioxin,double Phenol A,etc.,and high concentrations of inflammatory factors have been detected in diabetic patients,but PCB118,PFOS can activate the Islet ?-cells NLRP3 inflammasome through the ROS mechanism,lead to Islet inflammation,and then participate in the incidence of diabetes are not clear so far.The aim of this study was to investigate the impact and related mechanisms of the expression of ROS and NLRP3 inflammasome in mouse Islet ?-TC-6 cells caused by PCB118 and PFOS.Methods: 1.Mouse islet ?-TC-6 cells were cultured with PCB118 and PFOS as stimulating factors and ROS inhibitor NAC as the intervention factor.2.Cytotoxicity test: Cell Counting Kit-8 was used to detect the toxicity of PCB118 and PFOS under different concentrations to the cells for 48 h and 72 h.3.The experimental groups: when PCB118 intervention,the mouse islet ?-TC-6 cells were divided into dimethyl sulfoxide(DMSO)solvent control group,5nmol / L,10 nmol / L,20 nmol / L and PCB118 + NAC(10?mol/L NAC added in the best effect concentration to inhibit the production of ROS),and then were induced 48 h.When PFOS intervention,cells were divided into methanol solvent control group,1nmol / L,10 nmol / L,100 nmol / L and PFOS + NAC(10?mol/L NAC added in the best effect concentration to inhibit the production of ROS)and then were induced 48 h.4.The detection method:the toxicity to the cells caused by PCB118 and PFOS was detected by cell Counting Kit-8,ROS was measured by 2',7'-Dichlorofluorescin Diacetate(DCFH-DA),the expression of NLRP3,Pro-Caspase-1,Caspase-1,Pro-IL-1? and IL-1? protein were detected by Western-blot,while the expression of Interleukin-6(IL-6),Interleukin-18(IL-18)and C-C chemokine ligand 2(CCL-2,which is also called monocyte chemotactic protein 1,MCP-1)were measured by ELISA.5.Statistical analysis: we used statistical analysis software SPSS 17.0 for data analysis,data was represented by the mean and standard deviation(x?±s),One-way analysis of variance and LSD-t were used to analyze all experimental data,homogeneity test of variance was compared in every group,P<0.05 was considered to be statistically significant.Results:1.Cytotoxicity test showed that PCB118 had no significant toxicity at 48 h to cells,there was no significant difference between each group(P> 0.05);When the concentration was equal to or greater than 80 nmol / L at 72 h,PCB118 had significant toxicity to cells(P<0.05).The concentration of PFOS was 10000 nmol / L at 48 h and 72 h,PFOS had significant toxicity to cells(P <0.05).2.Compared with solvent control group,the levels of ROS and the expression of NLRP3,Caspase-1,IL-1? protein were up-regulated,the expression of Pro-Caspase-1,Pro-IL-1? protein were down-regulated in PCB118 and PFOS concentration group by dose-dependent manner of mouse islet ?-cells(P<0.05).the levels of ROS and the expression of NLRP3,Caspase-1,IL-1? protein were decreased by NAC intervention,the expression of Pro-Caspase-1,Pro-IL-1? protein were increased by NAC intervention in mouse islet ?-TC-6 cells(P<0.05).3.Compared with solvent control group,the levels of IL-6,IL-18 and CCL-2 expression were also up-regulated in PCB118 and PFOS concentration group by dose-dependent manner of mouse islet ?-TC-6 cells(P<0.05).the expression of IL-6,IL-18 and CCL-2 were decreased by NAC intervention in mouse islet ?-TC-6 cells(P<0.05).Conclusion: Our data support that PCB118,PFOS can activate the islet ?-cells NLRP3 inflammasome signaling via the oxidative stress pathway and involved in the occurrence of islet ?-cells inflammation.