While several previous studies have indicated the link between periodontal disease (PD) and myocardial infarction (MI), theunderlying mechanisms remain unclear. Autophagy, a cellular quality control process that is ac...While several previous studies have indicated the link between periodontal disease (PD) and myocardial infarction (MI), theunderlying mechanisms remain unclear. Autophagy, a cellular quality control process that is activated in several diseases, includingheart failure, can be suppressed by Porphyromonas gingivalis (P.g.). However, it is uncertain whether autophagy impairment byperiodontal pathogens stimulates the development of cardiac dysfunction after MI. Thus, this study aimed to investigate therelationship between PD and the development of MI while focusing on the role of autophagy. Neonatal rat cardiomyocytes(NRCMs) and MI model mice were inoculated with wild-type P.g. or gingipain-deficient P.g. to assess the effect of autophagyinhibition by P.g. Wild-type P.g.-inoculated NRCMs had lower cell viability than those inoculated with gingipain-deficient P.g. Thisstudy also revealed that gingipains can cleave vesicle-associated membrane protein 8 (VAMP8), a protein involved in lysosomalsensitive factor attachment protein receptors (SNAREs), at the 47th lysine residue, thereby inhibiting autophagy. Wild-type P.g.-inoculated MI model mice were more susceptible to cardiac rupture, with lower survival rates and autophagy activity thangingipain-deficient P.g.-inoculated MI model mice. After inoculating genetically modified MI model mice (VAMP8-K47A) with wildtype P.g., they exhibited significantly increased autophagy activation compared with the MI model mice inoculated with wild-typeP.g., which suppressed cardiac rupture and enhanced overall survival rates. These findings suggest that gingipains, which arevirulence factors of P.g., impair the infarcted myocardium by cleaving VAMP8 and disrupting autophagy. This study confirms thestrong association between PD and MI and provides new insights into the potential role of autophagy in this relationship.展开更多
AIM To investigate the morphologic changes of the myocardium and its relationship to serum bile acids in obstructive jaundice. METHODS Part Ⅰ: 35 rats were randomly assigned to three groups: Group Ⅰ (BDL1, n =...AIM To investigate the morphologic changes of the myocardium and its relationship to serum bile acids in obstructive jaundice. METHODS Part Ⅰ: 35 rats were randomly assigned to three groups: Group Ⅰ (BDL1, n =11), the common bile duct (CBD) was ligated and severed and killed after one week. Group Ⅱ (BDL2, n =11), the CBD was ligated and severed and killed after two weeks. Group Ⅲ (SO, n =13), the CBD was simply isolated. The hearts were taken for morphologic studies and blood was taken to determine the total serum bile acids (TAB). Part Ⅱ: 13 rats received gastric intubation of 10% 4ml/kg of sodium cholate, and their serum TBA and the morphologic changes of the heart were examined. RESULTS One to two weeks after the CBD was ligated and severed, the mitochondrium of the myocardium was damaged and the serum TBA obviously increased. When the rats were administered sodium cholate to make their peak blood concentration close to the average blood concentration in BDL2, their myocardium was damaged in a similar degree. CONCLUSION The myocardium was damaged in obstructive jaundice and the endogenous bile acids was one of the factors.展开更多
基金supported by Japan Society for the Promotion of Science (JSPS) KAKENHI Grant-in-Aid for Scientific Research (C) 20K08399 (to Yasuhiro Maejima)KAKENHI 19K18985,Grant-in-Aid for JSPS Fellows+1 种基金MSD Life Science FoundationPublic Interest Incorporated Foundation (to Yuka Shiheido-Watanabe)
文摘While several previous studies have indicated the link between periodontal disease (PD) and myocardial infarction (MI), theunderlying mechanisms remain unclear. Autophagy, a cellular quality control process that is activated in several diseases, includingheart failure, can be suppressed by Porphyromonas gingivalis (P.g.). However, it is uncertain whether autophagy impairment byperiodontal pathogens stimulates the development of cardiac dysfunction after MI. Thus, this study aimed to investigate therelationship between PD and the development of MI while focusing on the role of autophagy. Neonatal rat cardiomyocytes(NRCMs) and MI model mice were inoculated with wild-type P.g. or gingipain-deficient P.g. to assess the effect of autophagyinhibition by P.g. Wild-type P.g.-inoculated NRCMs had lower cell viability than those inoculated with gingipain-deficient P.g. Thisstudy also revealed that gingipains can cleave vesicle-associated membrane protein 8 (VAMP8), a protein involved in lysosomalsensitive factor attachment protein receptors (SNAREs), at the 47th lysine residue, thereby inhibiting autophagy. Wild-type P.g.-inoculated MI model mice were more susceptible to cardiac rupture, with lower survival rates and autophagy activity thangingipain-deficient P.g.-inoculated MI model mice. After inoculating genetically modified MI model mice (VAMP8-K47A) with wildtype P.g., they exhibited significantly increased autophagy activation compared with the MI model mice inoculated with wild-typeP.g., which suppressed cardiac rupture and enhanced overall survival rates. These findings suggest that gingipains, which arevirulence factors of P.g., impair the infarcted myocardium by cleaving VAMP8 and disrupting autophagy. This study confirms thestrong association between PD and MI and provides new insights into the potential role of autophagy in this relationship.
文摘AIM To investigate the morphologic changes of the myocardium and its relationship to serum bile acids in obstructive jaundice. METHODS Part Ⅰ: 35 rats were randomly assigned to three groups: Group Ⅰ (BDL1, n =11), the common bile duct (CBD) was ligated and severed and killed after one week. Group Ⅱ (BDL2, n =11), the CBD was ligated and severed and killed after two weeks. Group Ⅲ (SO, n =13), the CBD was simply isolated. The hearts were taken for morphologic studies and blood was taken to determine the total serum bile acids (TAB). Part Ⅱ: 13 rats received gastric intubation of 10% 4ml/kg of sodium cholate, and their serum TBA and the morphologic changes of the heart were examined. RESULTS One to two weeks after the CBD was ligated and severed, the mitochondrium of the myocardium was damaged and the serum TBA obviously increased. When the rats were administered sodium cholate to make their peak blood concentration close to the average blood concentration in BDL2, their myocardium was damaged in a similar degree. CONCLUSION The myocardium was damaged in obstructive jaundice and the endogenous bile acids was one of the factors.
