Diurnal variation of the human adipose transcriptome and the link to metabolic disease.

BackgroundCircadian (diurnal) rhythm is an integral part of the physiology of the body; specifically, sleep, feeding behavior and metabolism are tightly linked to the light-dark cycle dictated by earth's rotation.MethodsThe present study examines the effect of diurnal rhythm on gene expression in the subcutaneous adipose tissue of overweight to mildly obese, healthy individuals. In this well-controlled clinical study, adipose biopsies were taken in the morning, afternoon and evening from individuals in three study arms: treatment with the weight loss drug sibutramine/fasted, placebo/fed and placebo/fasted.ResultsThe results indicated that diurnal rhythm was the most significant driver of gene expression variation in the human adipose tissue, with at least 25% of the genes having had significant changes in their expression levels during the course of the day. The mRNA expression levels of core clock genes at a specific time of day were consistent across multiple subjects on different days in all three arms, indicating robust diurnal regulation irrespective of potential confounding factors. The genes essential for energy metabolism and tissue physiology were part of the diurnal signature. We hypothesize that the diurnal transition of the expression of energy metabolism genes reflects the shift in the adipose tissue from an energy-expending state in the morning to an energy-storing state in the evening. Consistent with this hypothesis, the diurnal transition was delayed by fasting and treatment with sibutramine. Finally, an in silico comparison of the diurnal signature with data from the publicly-available Connectivity Map demonstrated a significant association with transcripts that were repressed by mTOR inhibitors, suggesting a possible link between mTOR signaling, diurnal gene expression and metabolic regulation.ConclusionDiurnal rhythm plays an important role in the physiology and regulation of energy metabolism in the adipose tissue and should be considered in the selection of novel targets for the treatment of obesity and other metabolic disorders

Safety, tolerability, and immunogenicity after 1 and 2 doses of zoster vaccine in healthy adults >= 60 years of age

Background: Incidence and severity of herpes zoster (HZ) and postherpetic neuralgia increase with age, associated with age-related decrease in immunity to varicella-zoster virus (VZV). One dose of zoster vaccine (ZV) has demonstrated substantial protection against HZ; this study examined impact of a second dose of ZV. Methods: Randomized, double-blind, multicenter study with 210 subjects >= 60 years old compared immunity and safety profiles after one and two doses of ZV, separated by 6 weeks, vs. placebo. lmmunogenicity was evaluated using VZV interferon-gamma (IFN-gamma) enzyme-linked immunospot (ELISPOT) assay and VZV glycoprotein enzyme-linked immunosorbent antibody (gpELISA) assay. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card. Results: No serious vaccine-related AEs occurred. VZV IFN-gamma ELISPOT geometric mean count (GMC) of spot-forming cells per 106 peripheral blood mononuclear cells increased in the ZV group from 16.9 prevaccination to 49.5 and 32.8 at 2 and 6 weeks postdose 1, respectively. Two weeks, 6 weeks and 6 months postdose 2, GMC was 44.3, 42.9, and 36.5, respectively. GMC in the placebo group did not change during the study. The peak ELISPOT response occurred similar to 2 weeks after each ZV dose. The gpELISA geometric mean titers (GMTs) in the ZV group were higher than in the placebo group at 6 weeks after each dose. Correlation between the IFN-gamma ELISPOT and gpELISA assays was poor. Conclusions: ZV was generally well-tolerated and immunogenic in adults >= 60 years old. A second dose of ZV was generally safe, but did not boost VZV-specific immunity beyond levels achieved postdose 1. (C) 2011 Elsevier Ltd. All rights reserve