Small-Molecule Inhibitors of Cyclophilins Block Opening of the Mitochondrial Permeability Transition Pore and Protect Mice From Hepatic Ischemia/Reperfusion Injury

International audienceBackground & Aims: Hepatic ischemia-reperfusion injury is a complication of liver surgery that involves mitochondrial dysfunction resulting from mitochondrial permeability transition pore (mPTP) opening. Cyclophilin D (PPIF or CypD) is a peptidyl-prolyl cis-trans isomerase that regulates mPTP opening in the inner mitochondrial membrane. We investigated whether and how recently created small-molecule inhibitors of CypD prevent opening of the mPTP in hepatocytes and the resulting effects in cell models and livers of mice undergoing ischemia/reperfusion injuryMethods: We measured the activity of 9 small-molecule inhibitors of cyclophilins in an assay of CypD activity. The effects of the small-molecule CypD inhibitors or vehicle on mPTP opening were assessed by measuring mitochondrial swelling and calcium retention in isolated liver mitochondria from C57BL/6J (wild-type) and Ppif–/– (CypD knockout) mice and in primary mouse and human hepatocytes by fluorescence microscopy. We induced ischemia/reperfusion injury in livers of mice given a small-molecule CypD inhibitor or vehicle before and during reperfusion and collected samples of blood and liver for histologic analysis.Results: The compounds inhibited peptidyl-prolyl isomerase activity (half maximal inhibitory concentration values, 0.2–16.2 μmol/L) and, as a result, calcium-induced mitochondrial swelling, by preventing mPTP opening (half maximal inhibitory concentration values, 1.4–132 μmol/L) in a concentration-dependent manner. The most potent inhibitor (C31) bound CypD with high affinity and inhibited swelling in mitochondria from livers of wild-type and Ppif–/– mice (indicating an additional, CypD-independent effect on mPTP opening) and in primary human and mouse hepatocytes. Administration of C31 in mice with ischemia/reperfusion injury before and during reperfusion restored hepatic calcium retention capacity and oxidative phosphorylation parameters and reduced liver damage compared with vehicle.Conclusions:Recently created small-molecule inhibitors of CypD reduced calcium-induced swelling in mitochondria from mouse and human liver tissues. Administration of these compounds to mice during ischemia/reperfusion restored hepatic calcium retention capacity and oxidative phosphorylation parameters and reduced liver damage. These compounds might be developed to protect patients from ischemia/reperfusion injury after liver surgery or for other hepatic or nonhepatic disorders related to abnormal mPTP opening

Two-year outcome of patients after a first hospitalization for heart failure: A national observational study

SummaryBackgroundNational population-based management and outcome data for patients of all ages hospitalized for heart failure have rarely been reported.AimNational population-based management and outcome of patients of all ages hospitalized for heart failure have rarely been reported. The present study reports these results, based on 77% of the French population, for patients hospitalized for the first time for heart failure in 2009.MethodsThe study population comprised French national health insurance general scheme beneficiaries hospitalized in 2009 with a principal diagnosis of heart failure, after exclusion of those hospitalized for heart failure between 2006 and 2008 or with a chronic disease status for heart failure. Data were collected from the national health insurance information system (SNIIRAM).ResultsA total of 69,958 patients (mean age, 78 years; 48% men) were studied. The hospital mortality rate was 6.4%, with 1-month, 1-year and 2-year survival rates of 89%, 71% and 60%, respectively. Heart failure and all-cause readmission-free rates were 55% and 43% at 1 year and 27% and 17% at 2 years, respectively. Compared with a reference sample of 600,000 subjects, the age- and sex-standardized relative risk of death was 29 (95% confidence interval [CI] 28–29) at 2 years, 82 (95% CI 72–94) in subjects aged<50 years and 3 (95% CI 3–3) in subjects aged≥90 years. For subjects aged<70 years who survived 1 month after discharge, factors associated with a reduction in the 2-year mortality rate were: female sex; age<55 years; absence of co-morbidities; and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers, lipid-lowering agents or oral anticoagulants during the month following discharge. Poor prognostic factors were treatment with a loop diuretic before or after hospitalization and readmission for heart failure within 1 month after discharge.ConclusionsThis large population-based study confirms the severe prognosis of heart failure and the need to promote the use of effective medications and management designed to improve survival

First hospitalization for heart failure in France in 2009: Patient characteristics and 30-day follow-up

SummaryBackgroundThe incidence of heart failure (HF) is stable in industrialized countries, but its prevalence continues to increase, especially due to the ageing of the population, and mortality remains high.ObjectiveTo estimate the incidence in France and describe the management and short-term outcome of patients hospitalized for HF for the first time.MethodThe study population comprised French national health insurance general scheme beneficiaries (77% of the French population) hospitalized in 2009 with a principal diagnosis of HF after exclusion of those hospitalized for HF between 2006 and 2008 or with a chronic disease status for HF. Data were collected from the national health insurance information system (SNIIRAM).ResultsA total of 69,958 patients (mean age 78years; 48% men) were included. The incidence of first hospitalization for HF was 0.14% (≥55years, 0.5%; ≥90years, 3.1%). Compared with controls without HF, patients more frequently presented cardiovascular or other co-morbidities. The hospital mortality rate was 6.4% and the mortality rate during the 30days after discharge was 4.4% (3.4% without readmission). Among 30-day survivors, all-cause and HF 30-day readmission rates were 18% (<70years, 22%; ≥90years, 13%) and 5%, respectively. Reimbursements among 30-day survivors comprised at least a beta-blocker in 54% of cases, diuretics in 85%, angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) in 67%, a diuretic and ACEI/ARB combination in 23% and a beta-blocker, ACEI/ARB and diuretic combination in 37%.ConclusionPatients admitted for HF presented high rates of co-morbidity, readmission and death at 30days, and there remains room for improvement in their drug treatments; these findings indicate the need for improvement in return-home and therapeutic education programmes

Small-Molecule Inhibitors of Cyclophilins Block Opening of the Mitochondrial Permeability Transition Pore and Protect Mice From Hepatic Ischemia/Reperfusion Injury

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