PrrC, a Sco homologue from Rhodobacter sphaeroides, possesses thiol-disulfide oxidoreductase activity

PrrC is a Sco homologue in Rhodobacter sphaeroides that is associated with PrrBA, a two-component signal transduction system that induces photosynthesis gene expression in response to a decrease in oxygen tension. Although Sco proteins have been shown to bind copper the observation that they are structurally-related to thioredoxins suggested that they might possess thiol-disulfide oxidoreductase activity. Our results show that PrrC reduces Cu2+ to Cu+ and possesses disulfide reductase activity. These results indicate that some bacterial Sco proteins may have biochemical properties that are distinct from those of mitochondrial Sco proteins. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved

Corrigendum to "The CIRCORT database: Reference ranges and seasonal changes in diurnal salivary cortisol derived from a meta-dataset comprised of 15 field studies" [PNEC 73C (2016) 16-23]

In the published article we unintentionally missed to provide references to study #4 (see Table 1). The source data of study #4 were kindly provided by the TRAILS consortium (Rosmalen et al., 2005)

Aging, Health Behaviors, and the Diurnal Rhythm and Awakening Response of Salivary Cortisol

Background/Study Context: The cortisol diurnal rhythm has previously been examined in relation to age and health behaviors. However, less is known about the relationship between multiple health behaviors and diurnal cortisol in the context of aging, where it is possible that the impact of health behaviors on cortisol varies as a function of age. This study compared the awakening response and diurnal rhythm of cortisol in young versus older adults in relation to health behaviors. Methods: Twenty-four young students (aged 18–22) and 48 community-dwelling older adults (aged 65–88) completed an assessment of health behaviors (exercise, smoking, sleep, diet, alcohol) over the past year. Salivary cortisol was measured over the course of 1 day: immediately upon awakening, 30 min later, and then 3, 6, 9, and 12 h post awakening. Repeated measures/univariate analysis of variance (ANOVA) was used to test main effects of age and health behaviors, and any interaction effects in relation to diurnal cortisol. Results: Older adults displayed significantly reduced cortisol upon awakening, a lower cortisol awakening response, and a flatter diurnal profile represented by a reduced area under the curve and cortisol slope. There was also a significant interaction of age, cortisol, and diet; younger adults with a higher fat and lower fruit and vegetable intake exhibited the flattened diurnal cortisol phenotype of the older adults. Conclusion: These findings suggest that the diurnal rhythm and awakening response of salivary cortisol is significantly reduced in older adults and that variations in the cortisol diurnal rhythm of younger adults are associated with dietary factors. Younger adults with a poor quality of food intake may be vulnerable to a reduction in the amplitude of the cortisol diurnal profile and this may have implications for other aspects of health

Antecedent longitudinal changes in body mass index are associated with diurnal cortisol curve features: The multi-ethnic study of atherosclerosis

CONTEXT: Prior studies have shown a cross-sectional association between body mass index (BMI) and salivary diurnal cortisol profile features (cortisol features); however, to our knowledge prior population-based studies have not examined the longitudinal association of body-mass index (BMI) with cortisol features. OBJECTIVE: To examine the association of (1) prior annual BMI percent change over 7 years with cortisol features, (2) baseline cortisol features with subsequent change in BMI over 6 years and (3) the association of change in cortisol features with change in BMI over 6 years. DESIGN: Longitudinal study SETTING: Multi-Ethnic Study of Atherosclerosis (MESA) Stress I & II Studies (2004-2006 & 2010-2012) PARTICIPANTS: 1,685 ethnically diverse men and women attended either MESA Stress exam (mean age 65 ± 10 years at MESA Stress I; mean age 69 ± 9 years at MESA Stress II). OUTCOME MEASURES: Log-transformed cortisol features including wake-up cortisol, cortisol awakening response, early decline slope (30 minutes to 2 hours post-awakening), late decline slope (2 hours post-awakening to bedtime), bedtime, and total area under the curve (AUC) cortisol. RESULTS: Over 7 years, following multivariable adjustment, (1) a 1% higher prior annual BMI % increase was associated with a 2.9% (95% CI: −5.0%, −0.8%) and 3.0% (95% CI: −4.7%, −1.4%) lower current wake-up and total AUC cortisol, respectively; (2) there was no significant association between baseline cortisol features and subsequent change in BMI and (3) among participants with BMI ≥ 30 kg/m(2), flattening of the late decline slope was associated with increases in BMI (every 1-unit increase late decline slope were associated with a 12.9% increase (95%CI: −1%, 26.8%) in BMI, respectively). CONCLUSIONS: We found a significant association between prior annual BMI % change and cortisol features, but no significant association between baseline cortisol features and subsequent change in BMI. In participants with obesity increases in BMI were associated with less pronounced declined. Collectively, our results suggest that greater adiposity may lead to a blunted diurnal cortisol profile

Adiposity and cancer risk: new mechanistic insights from epidemiology

Excess body adiposity, commonly expressed as body mass index (BMI), is a risk factor for many common adult cancers. Over the past decade, epidemiological data have shown that adiposity-cancer risk associations are specific for gender, site, geographical population, histological subtype and molecular phenotype. The biological mechanisms underpinning these associations are incompletely understood but need to take account of the specificities observed in epidemiology to better inform future prevention strategies