Long-term hepatitis B virus infection of rhesus macaques requires suppression of host immunity.

Hepatitis B virus has infected a third of the world's population, and 296 million people are living with chronic infection. Chronic infection leads to progressive liver disease, including hepatocellular carcinoma and liver failure, and there remains no reliable curative therapy. These gaps in our understanding are due, in large part, to a paucity of animal models of HBV infection. Here, we show that rhesus macaques regularly clear acute HBV infection, similar to adult humans, but can develop long-term infection if immunosuppressed. Similar to patients, we longitudinally detected HBV DNA, HBV surface antigen, and HBV e antigen in the serum of experimentally infected animals. In addition, we discovered hallmarks of HBV infection in the liver, including RNA transcription, HBV core and HBV surface antigen translation, and covalently closed circular DNA biogenesis. This pre-clinical animal model will serve to accelerate emerging HBV curative therapies into the clinic.

Mitochondrial energetics in the heart in obesity-related diabetes: direct evidence for increased uncoupled respiration and activation of uncoupling proteins.

OBJECTIVE: In obesity and diabetes, myocardial fatty acid utilization and myocardial oxygen consumption (MVo(2)) are increased, and cardiac efficiency is reduced. Mitochondrial uncoupling has been proposed to contribute to these metabolic abnormalities but has not been directly demonstrated. RESEARCH DESIGN AND METHODS: Oxygen consumption and cardiac function were determined in db/db hearts perfused with glucose or glucose and palmitate. Mitochondrial function was determined in saponin-permeabilized fibers and proton leak kinetics and H(2)O(2) generation determined in isolated mitochondria. RESULTS: db/db hearts exhibited reduced cardiac function and increased MVo(2). Mitochondrial reactive oxygen species (ROS) generation and lipid and protein peroxidation products were increased. Mitochondrial proliferation was increased in db/db hearts, oxidative phosphorylation capacity was impaired, but H(2)O(2) production was increased. Mitochondria from db/db mice exhibited fatty acid-induced mitochondrial uncoupling that is inhibitable by GDP, suggesting that these changes are mediated by uncoupling proteins (UCPs). Mitochondrial uncoupling was not associated with an increase in UCP content, but fatty acid oxidation genes and expression of electron transfer flavoproteins were increased, whereas the content of the F1 alpha-subunit of ATP synthase was reduced. CONCLUSIONS: These data demonstrate that mitochondrial uncoupling in the heart in obesity and diabetes is mediated by activation of UCPs independently of changes in expression levels. This likely occurs on the basis of increased delivery of reducing equivalents from beta-oxidation to the electron transport chain, which coupled with decreased oxidative phosphorylation capacity increases ROS production and lipid peroxidation.