AIM: To investigate whether ezetimibe ameliorates hepatic steatosis and induces autophagy in a rat model of obesity and type 2 diabetes. METHODS: Male age-matched lean control LETO and obese and diabetic OLETF rats we...AIM: To investigate whether ezetimibe ameliorates hepatic steatosis and induces autophagy in a rat model of obesity and type 2 diabetes. METHODS: Male age-matched lean control LETO and obese and diabetic OLETF rats were administered either PBS or ezetimibe(10 mg/kg per day) via stomach gavage for 20 wk. Changes in weight gain and energy intake were regularly monitored. Blood and liver tissue were harvested after overnight fasting at the end of study. Histological assessment was performed in liver tissue. The concentrations of glucose, insulin, triglycerides(TG), free fatty acids(FFA), and total cholesterol(TC) in blood and TG, FFA, and TG in livertissue were measured. m RNA and protein abundance involved in autophagy was analyzed in the liver. To investigate the effect of ezetimibe on autophagy and reduction in hepatic fat accumulation, human Huh7 hepatocytes were incubated with ezetimibe(10 μmol/L) together with or without palmitic acid(PA, 0.5 mmol/L, 24 h). Transmission electron microscopy(TEM) was employed to demonstrate effect of ezetimibe on autophagy formation. Autophagic flux was measured with bafilomycin A1, an inhibitor of autophagy and following immunoblotting for autophagy-related protein expression.RESULTS: In the OLETF rats that received ezetimibe(10 mg/kg per day), liver weight were significantly decreased by 20% compared to OLETF control rats without changes in food intake and body weight(P < 0.05). Lipid parameters including TG, FFA, and TC in liver tissue of ezetimibe-administrated OLETF rats were dramatically decreased at least by 30% compared to OLETF controls(P < 0.01). The serum glucose, insulin, HOMA-IR, and lipid profiles were also improved by ezetimibe(P < 0.05). In addition, autophagy-related m RNA expression including ATG5, ATG6, and ATG7 and the protein level of microtubule-associated protein light chain 3(LC3) were significantly increased in the liver in rats that received ezetimibe(P < 0.05). Likewise, for hepatocytes cultured in vitro, ezetimibe treatment significantly decreased PA-induced fat accumulation and increased PA-reduced m RNA and protein expression involved in autophagy(P < 0.05). Ezetimibe-increased autophagosomes was observed in TEM analysis. Immunoblotting analysis of autophagy formation with an inhibitor of autophagy demonstrated that ezetimibe-increased autophagy resulted from increased autophagic flux. CONCLUSION: The present study demonstrates that ezetimibe-mediated improvement in hepatic steatosis might involve the induction of autophagy.展开更多
AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with tra...AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with transplant kidney biopsies demonstrating features of both PVN and acute rejection(AR). PVN was defined by the presence of typical viral cytopathic effect on routine sections and positive polyomavirus SV40 large-T antigen immunohistochemistry. AR was identified by endarteritis(v1 by Banff criteria). All cases were subjected to chart review in order to determine clinical presentation, treatment course and outcomes. Outcomes were recorded with a length of follow-up of at least one year or time to nephrectomy. RESULTS: Of 94 renal allograft recipients who developed PVN over an 11-year period at our institution, we identified 7(7.4%) with viral cytopathic changes, SV40 large T antigen staining, and endarteritis in the same biopsy specimen, indicative of concurrent PVN and AR. Four arose after reduction of immunosuppression(IS)(for treatment of PVN in 3 and tuberculosis in 1), and 3 patients had no decrease of IS before developing simultaneous concurrent disease. Treatment consisted of reduced oral IS and leflunomide for PVN, and antirejection therapy. Three of 4 patients who developed endarteritis in the setting of reduced IS lost their grafts to rejection. All 3 patients with simultaneous PVN and endarteritis cleared viremia and were stable at 1 year of follow up. Patients with endarteritis and PVN arising in a background of reduced IS had more severe rejection and poorer outcome.CONCLUSION: Concurrent PVN and endarteritis may be more frequent than is currently appreciated and may occur with or without prior reduction of IS.展开更多
基金Supported by Samsung Biomedical Research Institute,Grant No.SBRI C-B1-111-3National Research Foundation of Korea,No.2012R1A1A2009143/2013027171Korean Diabetes Association(to Park CY,2014S-1)
文摘AIM: To investigate whether ezetimibe ameliorates hepatic steatosis and induces autophagy in a rat model of obesity and type 2 diabetes. METHODS: Male age-matched lean control LETO and obese and diabetic OLETF rats were administered either PBS or ezetimibe(10 mg/kg per day) via stomach gavage for 20 wk. Changes in weight gain and energy intake were regularly monitored. Blood and liver tissue were harvested after overnight fasting at the end of study. Histological assessment was performed in liver tissue. The concentrations of glucose, insulin, triglycerides(TG), free fatty acids(FFA), and total cholesterol(TC) in blood and TG, FFA, and TG in livertissue were measured. m RNA and protein abundance involved in autophagy was analyzed in the liver. To investigate the effect of ezetimibe on autophagy and reduction in hepatic fat accumulation, human Huh7 hepatocytes were incubated with ezetimibe(10 μmol/L) together with or without palmitic acid(PA, 0.5 mmol/L, 24 h). Transmission electron microscopy(TEM) was employed to demonstrate effect of ezetimibe on autophagy formation. Autophagic flux was measured with bafilomycin A1, an inhibitor of autophagy and following immunoblotting for autophagy-related protein expression.RESULTS: In the OLETF rats that received ezetimibe(10 mg/kg per day), liver weight were significantly decreased by 20% compared to OLETF control rats without changes in food intake and body weight(P < 0.05). Lipid parameters including TG, FFA, and TC in liver tissue of ezetimibe-administrated OLETF rats were dramatically decreased at least by 30% compared to OLETF controls(P < 0.01). The serum glucose, insulin, HOMA-IR, and lipid profiles were also improved by ezetimibe(P < 0.05). In addition, autophagy-related m RNA expression including ATG5, ATG6, and ATG7 and the protein level of microtubule-associated protein light chain 3(LC3) were significantly increased in the liver in rats that received ezetimibe(P < 0.05). Likewise, for hepatocytes cultured in vitro, ezetimibe treatment significantly decreased PA-induced fat accumulation and increased PA-reduced m RNA and protein expression involved in autophagy(P < 0.05). Ezetimibe-increased autophagosomes was observed in TEM analysis. Immunoblotting analysis of autophagy formation with an inhibitor of autophagy demonstrated that ezetimibe-increased autophagy resulted from increased autophagic flux. CONCLUSION: The present study demonstrates that ezetimibe-mediated improvement in hepatic steatosis might involve the induction of autophagy.
文摘AIM: To describe the clinicopathologic features of concurrent polyomavirus nephropathy(PVN) and endarteritis due to rejection in renal allografts.METHODS: We searched our electronic records database for cases with transplant kidney biopsies demonstrating features of both PVN and acute rejection(AR). PVN was defined by the presence of typical viral cytopathic effect on routine sections and positive polyomavirus SV40 large-T antigen immunohistochemistry. AR was identified by endarteritis(v1 by Banff criteria). All cases were subjected to chart review in order to determine clinical presentation, treatment course and outcomes. Outcomes were recorded with a length of follow-up of at least one year or time to nephrectomy. RESULTS: Of 94 renal allograft recipients who developed PVN over an 11-year period at our institution, we identified 7(7.4%) with viral cytopathic changes, SV40 large T antigen staining, and endarteritis in the same biopsy specimen, indicative of concurrent PVN and AR. Four arose after reduction of immunosuppression(IS)(for treatment of PVN in 3 and tuberculosis in 1), and 3 patients had no decrease of IS before developing simultaneous concurrent disease. Treatment consisted of reduced oral IS and leflunomide for PVN, and antirejection therapy. Three of 4 patients who developed endarteritis in the setting of reduced IS lost their grafts to rejection. All 3 patients with simultaneous PVN and endarteritis cleared viremia and were stable at 1 year of follow up. Patients with endarteritis and PVN arising in a background of reduced IS had more severe rejection and poorer outcome.CONCLUSION: Concurrent PVN and endarteritis may be more frequent than is currently appreciated and may occur with or without prior reduction of IS.
