| Background:Periodontitis is a chronic infectious disease characterized by destruction of periodontal connective tissue and alveolar bone resorption,which is the primary cause of tooth loss in adults.Non-alcoholic fatty liver disease(NAFLD)is one of the most important chronic liver diseases in the world.Epidemiological and experimental studies have shown that there is a close relationship between periodontitis and NAFLD,and the oxidative stress response induced by excessive reactive oxygen species(ROS)is involved in the occurrence and development of periodontitis-related liver injury but the specific mechanism is unclear.At present,clinical periodontitis uses basic periodontal treatment supplemented with antibiotic drug treatment as the main means.It can not only inhibit local periodontal tissue damage,but also reduce systemic inflammation,controlling blood sugar,blood lipid metabolism,and improving liver and kidney function,but there are still some drawbacks,such as drug therapeutic effects not ideal and easy to produce drug resistance.Therefore,it is particularly critical to find other effective treatments.Antioxidants,as a defensive factor,can not only eliminate ROS in the body,but also regulate the redox state of cells,and then delay or terminate the oxidative damage of cells,which has attracted more and more attention.Therefore,this study established a rat periodontitis model by ligation+P.gingivalis infection method,detected the changes of oxidative stress-related indicators in rat liver tissue,and clarified the role of oxidative stress in periodontitis-induced liver injury,and the classic anti-oxidant drug resveratrol was further used to intervene to preliminarily explore the mechanism of resveratrol in alleviating periodontitis-related liver injury by ameliorating oxidative stress.Methods:1.18 8-week-old male Wistar rats were randomly divided into three groups:control group,periodontitis group and resveratrol intervention group,with 6 rats in each group.In periodontitis group,orthodontic wire with a diameter of 0.2mm was ligated to the teeth necks of the maxillary first molar,and 100μL of 1×10~9CFU/m L P.gingivalis ATCC33277 suspended in 2%CMC was inoculated into the gingival sulcus.Resveratrol intervention group was given oral resveratrol(30mg/kg, suspended in 0.5%CMC)daily to construct the periodontitis model.The control group was inoculated with 2%CMC without ligation and 0.5%CMC orally.After 6 weeks,the following indexes were detected.2.Detection of periodontal related indicators:visual observation of periodontal soft tissue changes and Micro-CT evaluation of alveolar bone resorption.3.Clinical and pathological examination of liver:(1)Visual observation of liver morphology and detection of liver function related indexes:AST,ALT,ALP.(2)HE staining and oil red O staining were used to evaluate the histopathological changes of liver.4.Detection of oxidative stress related indexes in liver tissue:(1)Detection of lipid peroxides MDA and antioxidant CAT and GSH expression levels.(2)The structure and function of mitochondria were detected by transmission electron microscope(TEM),Mito SOX,JC-1 and ATP.(3)The mRNA and protein expressions of oxidative stress related factors like Keap1, Nrf2,NQO1 and HO-1 were detected by qRT-PCR and immunohistochemistry.Result:1.Detection of periodontal related indexes:compared with the control group,gingival swelling and bleeding were appeared in periodontitis group;Micro-CT results showed that alveolar bone resorption was serious in periodontitis group.In the resveratrol intervention group,periodontal soft tissue injury was improved and alveolar bone resorption decreased..2.Liver clinical indexes,HE staining and oil red O staining were detected:compared with the control group,a large number of vacuolar changes and red lipid droplets appeared in the hepatocytes of periodontitis group,accompanied by the increase of ALT,AST and ALP.In the resveratrol intervention group,the color and morphology of the liver recovered,and the intrahepatic vacuolation,lipid droplets and the expression of liver function index were significantly reduced.3.Detection of oxidative stress related indicators:(1)Compared with the control group,the expression levels of lipid peroxidation product MDA were increased,and the expression levels of antioxidant CAT and GSH were decreased in liver tissue of periodontitis rats.In the resveratrol intervention group,the expression of MDA decreased,and the expression of CAT and GSH increased in liver tissue.(2)Detection of correlation indexes of mitochondrial structure and function were detected:compared with the control group,the integrity of liver mitochondrial structure was damaged,the level of mitochondrial ROS was increased,the level of mitochondrial membrane potential and ATP was decreased in periodontitis group, suggesting mitochondrial dysfunction.In the resveratrol intervention group,the structure and dysfunction of liver mitochondria were improved.(3)The results of qRT-PCR and immunohistochemical staining showed that compared with the control group,the expression of Nrf2,NQO1,HO-1 mRNA and protein was down regulated and the expression of Keap1 mRNA and protein was up-regulated in the liver tissue of periodontitis rats.In the resveratrol intervention group,the expression levels of the above factors were reversed.Conclusions:1.Periodontitis induced liver injury in rats.2.Oxidative stress was involved in the process of liver injury induced by periodontitis.3.Resveratrol can alleviate periodontitis-related liver injury by ameliorating oxidative stress in rats. |
PDF Full Text Request