A regulatory pathway linking caffeine action, mood and the diurnal clock

International audienceDepression is a leading cause of disability worldwide. Circadian abnormalities and mood changes are symptoms of depression. The psychostimulant caffeine alters wakefulness and alleviates other depression-related symptoms during chronic intake, but the underlying mechanisms are unclear. It is not known, whether and how acute caffeine administration affects mood. Molecular approaches, transgenic mouse models, pharmacological intervention and behavioral analysis were combined to uncover a regulatory pathway, which connects caffeine action with diurnal signaling via the key dopaminergic protein DARPP-32 and alters mood-related phenotypes in mice, which are often assessed in the context of antidepressant action. We observed that Thr75-DARPP-32 binds to the circadian regulator CLOCK and disrupts CLOCK:BMAL1 chromatin binding, thereby affecting gene expression. T75A-DARPP-32 mutant mice show reduced caffeine effects on CLOCK:BMAL1 and lack caffeine-induced effects on mood. This study provides a link between caffeine, diurnal signaling and mood-related behaviors, which may open new perspectives for our understanding of antidepressant mechanisms in the mouse brain

A translational systems biology approach in both animals and humans identifies a functionally related module of accumbal genes involved in the regulation of reward processing and binge drinking in males

BACKGROUND: The mesolimbic dopamine system, composed primarily of dopaminergic neurons in the ventral tegmental area that project to striatal structures, is considered to be the key mediator of reinforcement-related mechanisms in the brain. Prompted by a genome-wide association meta-analysis implicating the Ras-specific guanine nucleotide-releasing factor 2 (RASGRF2) gene in the regulation of alcohol intake in men, we have recently shown that male Rasgrf2(−/−) mice exhibit reduced ethanol intake and preference accompanied by a perturbed mesolimbic dopamine system. We therefore propose that these mice represent a valid model to further elucidate the precise genes and mechanisms regulating mesolimbic dopamine functioning. METHODS: Transcriptomic data from the nucleus accumbens (NAcc) of male Rasgrf2(−/−) mice and wild-type controls were analyzed by weighted gene coexpression network analysis (WGCNA). We performed follow-up genetic association tests in humans using a sample of male adolescents from the IMAGEN study characterized for binge drinking (n = 905) and ventral striatal activation during an fMRI reward task (n = 608). RESULTS: The WGCNA analyses using accumbal transcriptomic data revealed 37 distinct “modules,” or functionally related groups of genes. Two of these modules were significantly associated with Rasgrf2 knockout status: M5 (p < 0.001) and M6 (p < 0.001). In follow-up translational analyses we found that human orthologues for the M5 module were significantly (p < 0.01) enriched with genetic association signals for binge drinking in male adolescents. Furthermore, the most significant locus, originating from the EH-domain containing 4 (EHD4) gene (p < 0.001), was also significantly associated with altered ventral striatal activity in male adolescents performing an fMRI reward task (p(empirical) < 0.001). LIMITATIONS: It was not possible to determine the extent to which the M5 module was dysregulated in Rasgrf2(−/−) mice by perturbed mesolimbic dopamine signalling or by the loss of Rasgrf2 function in the NAcc. CONCLUSION: Taken together, our findings indicate that the accumbal M5 module, initially identified as being dysregulated in male Rasgrf2(−/−) mice, is also relevant for human alcohol-related phenotypes potentially through the modulation of reinforcement mechanisms in the NAcc. We therefore propose that the genes comprising this module represent important candidates for further elucidation within the context of alcohol-related phenotypes

Management of acute exacerbations of chronic obstructive pulmonary disease (COPD). Guidelines from the Société de pneumologie de langue française (summary).

Chronic obstructive pulmonary disease (COPD) is the chronic respiratory disease with the most important burden on public health in terms of morbidity, mortality and health costs. For patients, COPD is a major source of disability because of dyspnea, restriction in daily activities, exacerbation, risk of chronic respiratory failure and extra-respiratory systemic organ disorders. The previous French Language Respiratory Society (SPLF) guidelines on COPD exacerbations were published in 2003. Using the GRADE methodology, the present document reviews the current knowledge on COPD exacerbation through 4 specific outlines: (1) epidemiology, (2) clinical evaluation, (3) therapeutic management and (4) prevention. Specific aspects of outpatients and inpatients care are discussed, especially regarding assessment of exacerbation severity and pharmacological approach.[Prise en charge des exacerbations de la bronchopneumopathie chronique obstructive (BPCO). Recommandations de la Société de pneumologie de langue française (texte court)] La bronchopneumopathie chronique obstructive (BPCO) est la maladie respiratoire chronique dont le poids sur la santé publique est le plus grand par sa morbidité, sa mortalité et les dépenses de santé qu’elle induit. Pour les individus atteints, la BPCO est une source majeure de handicap du fait de la dyspnée, de la limitation d’activité, des exacerbations, du risque d’insuffisance respiratoire chronique et des manifestations extra-respiratoires qu’elle entraîne. Les précédentes recommandations de la Société de pneumologie de langue française (SPLF) sur la prise en charge des exacerbations BPCO date de 2003. Se fondant sur une méthodologie adaptée de GRADE, le présent document propose une actualisation de la question des exacerbations de BPCO en développant un argumentaire couvrant quatre champs d’investigation : (1) épidémiologie, (2) évaluation clinique, (3) prise en charge thérapeutique et (4) prévention. Les modalités spécifiques de la prise en charge hospitalière et ambulatoire y sont discutées, particulièrement les aspects relevant de l’évaluation de la sévérité de l’exacerbation et de la prise en charge pharmacologique