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NQO1 is a FAD containing NAD(P)H-dependent oxidoreductase that catalyzes the reduction of quinones and related substrates. In cells, NQO1 participates in a number of binding interactions with other proteins and mRNA and these interactions may be influenced by the concentrations of reduced pyridine nucleotides. NAD(P)H can protect NQO1 from proteolytic digestion suggesting that binding of reduced pyridine nucleotides results in a change in NQO1 structure. We have used purified NQO1 to demonstrate the addition of NAD(P)H induces a change in the structure of NQO1; this results in the loss of immunoreactivity to antibodies that bind to the C-terminal domain and to helix 7 of the catalytic core domain. Under normal cellular conditions NQO1 is not immunoprecipitated by these antibodies, however, following treatment with β-lapachone which caused rapid oxidation of NAD(P)H NQO1 could be readily pulled-down. Similarly, immunostaining for NQO1 was significantly increased in cells following treatment with β-lapachone demonstrating that under non-denaturing conditions the immunoreactivity of NQO1 is reflective of the NAD(P)+/NAD(P)H ratio. In untreated human cells, regions with high intensity immunostaining for NQO1 co-localize with acetyl α-tubulin and the NAD+-dependent deacetylase Sirt2 on the centrosome(s), the mitotic spindle and midbody during cell division. These data provide evidence that during the centriole duplication cycle NQO1 may provide NAD+ for Sirt2-mediated deacetylation of microtubules. Overall, NQO1 may act as a redox-dependent switch where the protein responds to the NAD(P)+/NAD(P)H redox environment by altering its structure promoting the binding or dissociation of NQO1 with target macromolecules. [ABSTRACT FROM AUTHOR]

Interleukin 10tm1Cgn (IL 10tm) mice have been utilized as a model of chronic inflammation and declining health span because of their propensity to develop chronic activation in NFkB pathways, skeletal muscle and cardiac changes, and mitochondrial dysfunction. We hypothesized that older IL 10tm frail mice would have alterations similar to frail, older humans in measured parameters of glucose metabolism, oxygen consumption (VO2), respiratory quotient (RQ), spontaneous locomotor activity, body composition and plasma adipokine levels. To test this hypothesis, we investigated these metabolic parameters in cohorts of 3, 10, and 20 month old IL 10tm female mice and age and gender matched C57Bl/6 mice. Insulin sensitivity, glucose homeostasis, locomotor activity and RQ were not significantly altered between the two strains of mice. Interestingly, old IL 10tm mice had significantly decreased VO2 when normalized by lean mass, but not when normalized by fat mass or the lean/fat mass ratio. NMR based body composition analysis and dissection weights show that fat mass is decreased with age in IL 10tm mice compared to controls. Further, plasma adiponectin and leptin were also decreased in IL 10tm.These findings suggest that frailty observed in this mouse model of chronic inflammation may in part be driven by alterations in fat mass, hormone secretion and energy metabolism. [ABSTRACT FROM AUTHOR]

Objective: Alzheimer disease (AD) is a progressive, degenerative and irreversible neurological disorder with few therapies available. In search for new potential targets, increasing evidence suggests a role for the endocannabinoid system (ECS) in the regulation of neurodegenerative processes. Methods: We have studied the gene expression status and the epigenetic regulation of ECS components in peripheral blood mononuclear cells (PBMCs) of subjects with late-onset AD (LOAD) and age-matched controls (CT). Results: We found an increase in fatty acid amide hydrolase (faah) gene expression in LOAD subjects (2.30±0.48) when compared to CT (1.00±0.14; *p<0.05) and no changes in the mRNA levels of any other gene of ECS elements. Consistently, we also observed in LOAD subjects an increase in FAAH protein levels (CT: 0.75±0.04; LOAD: 1.11±0.15; *p<0.05) and activity (pmol/min per mg protein CT: 103.80±8.73; LOAD: 125.10±4.00; *p,0.05), as well as a reduction in DNA methylation at faah gene promoter (CT: 55.90±4.60%; LOAD: 41.20±4.90%; *p<0.05). Conclusions: Present findings suggest the involvement of FAAH in the pathogenesis of AD, highlighting the importance of epigenetic mechanisms in enzyme regulation; they also point to FAAH as a new potential biomarker for AD in easily accessible peripheral cells. [ABSTRACT FROM AUTHOR]