Reported and Recorded Sleepiness in Obesity and Depression.

BACKGROUND: Obesity and depression are both associated with changes in sleep/wake regulation, with potential implications for individualized treatment especially in comorbid individuals suffering from both. However, the associations between obesity, depression, and subjective, questionnaire-based and objective, EEG-based measurements of sleepiness used to assess disturbed sleep/wake regulation in clinical practice are not well known. OBJECTIVES: The study investigates associations between sleep/wake regulation measures based on self-reported subjective questionnaires and EEG-derived measurements of sleep/wake regulation patterns with depression and obesity and how/whether depression and/or obesity affect associations between such self-reported subjective questionnaires and EEG-derived measurements. METHODS: Healthy controls (HC, NHC = 66), normal-weighted depressed (DEP, NDEP = 16), non-depressed obese (OB, NOB = 68), and obese depressed patients (OBDEP, NOBDEP = 43) were included from the OBDEP (Obesity and Depression, University Leipzig, Germany) study. All subjects completed standardized questionnaires related to daytime sleepiness (ESS), sleep quality and sleep duration once as well as questionnaires related to situational sleepiness (KSS, SSS, VAS) before and after a 20 min resting state EEG in eyes-closed condition. EEG-based measurements of objective sleepiness were extracted by the VIGALL algorithm. Associations of subjective sleepiness with objective sleepiness and moderating effects of obesity, depression, and additional confounders were investigated by correlation analyses and regression analyses. RESULTS: Depressed and non-depressed subgroups differed significantly in most subjective sleepiness measures, while obese and non-obese subgroups only differed significantly in few. Objective sleepiness measures did not differ significantly between the subgroups. Moderating effects of obesity and/or depression on the associations between subjective and objective measures of sleepiness were rarely significant, but associations between subjective and objective measures of sleepiness in the depressed subgroup were systematically weaker when patients comorbidly suffered from obesity than when they did not. CONCLUSION: This study provides some evidence that both depression and obesity can affect the association between objective and subjective sleepiness. If confirmed, this insight may have implications for individualized diagnosis and treatment approaches in comorbid depression and obesity.

A high-throughput screen measuring ubiquitination of p53 by human mdm2.

Tumor suppressor p53 is typically maintained at low levels in normal cells. In response to cellular stresses, such as DNA damage, p53 is stabilized and can stimulate responses leading to cell cycle arrest or apoptosis. Corresponding to its central role in preventing propagation of damaged cells, mutation or deletion of p53 is found in nearly 50% of all human tumors. Mdm2 (mouse-d-minute 2) and its human ortholog (hmdm2 or hdm2) catalyze the ubiquitination of p53, targeting it for degradation via the proteosome. Thus, the activity of mdm2 is inversely correlated with p53 levels. Based on this, inhibition of human mdm2 activity by a small-molecule therapeutic will lead to net stabilization of p53 and be the basis for development of a novel cancer therapeutic. Previous high-throughput screening assays of mdm2 measured the autoubiquitination activity of mdm2, which occurs in the absence of an acceptor substrate such as p53. The major drawback to this approach is that inhibitors of mdm2 autoubiquitination may lead to a net stabilization of mdm2 and thus have the opposite effect of inhibitors that interfere with p53 ubiquitination. The authors describe the development, validation, and execution of a high-throughput screening measuring the ubiquitination of p53 by mdm2, with p53 labeled with europium and the other substrate (Ub-UbcH5b) labeled with a Cy5 on the ubiquitin. After confirming that known inhibitors are detected with this assay, it was successfully automated and used to query >600,000 compounds from the GlaxoSmithKline collection for mdm2 inhibitors.