Circadian clock communication during homeostasis and ageing

Astrocyte regulation of behavioral outputs: the versatile roles of calcium

Behavior arises from coordinated brain-wide neural and glial networks, enabling organisms to perceive, interpret, and respond to stimuli. Astrocytes play an important role in shaping behavioral output, yet the underlying molecular mechanisms are not fully understood. Astrocytes respond to intrinsic and extrinsic cues with calcium (Ca2+) fluctuations, which are highly heterogeneous across spatio-temporal scales, contexts, and brain regions. This heterogeneity allows astrocytes to exert dynamic regulatory effects on neuronal function but has made it challenging to understand the precise mechanisms and pathways linking astrocytic Ca2+ to specific behavioral outcomes, and the functional relevance of these signals remains unclear. Here, we review recent literature uncovering roles for astrocytic Ca2+ signaling in a wide array of behaviors, including cognitive, homeostatic, and affective focusing on its physiological roles, and potential pathological implications. We specifically highlight how different types of astrocytic Ca2+ signals are linked to distinct behavioral outcomes and discuss limitations and unanswered questions that remain to be addressed.

Dietary timing enhances exercise by modulating fat-muscle crosstalk via adipocyte AMPKα2 signaling

Feeding rhythms regulate exercise performance and muscle energy metabolism. However, the mechanisms regulating adipocyte functions remain unclear. Here, using multi-omics analyses, involving (phospho-)proteomics and lipidomics, we found that day-restricted feeding (DRF) regulates diurnal rhythms of the mitochondrial proteome, neutral lipidome, and nutrient-sensing pathways in mouse gonadal white adipose tissue (GWAT). Adipocyte-specific knockdown of Prkaa2 (the gene encoding AMPKα2) impairs physical endurance. This defect is associated with altered rhythmicity in acyl-coenzyme A (CoA) metabolism-related genes, a loss of rhythmicity in the GWAT lipidome, and circadian remodeling of serum metabolites-in particular, lactate and succinate. We also found that adipocyte Prkaa2 regulates muscle clock genes during DRF. Notably, oral administration of the AMPK activator C29 increases endurance and muscle functions in a time-of-day manner, which requires intact adipocyte AMPKα2 signaling. Collectively, our work defines adipocyte AMPKα2 signaling as a critical regulator of circadian metabolic coordination between fat and muscle, thereby enhancing exercise performance.

Nutrition, Lifestyle, and Environmental Factors in Lung Homeostasis and Respiratory Health

The lungs play a vital role in maintaining homeostasis by facilitating gas exchange and serving as a structural and immune barrier. External factors, including nutrition, lifestyle, and environmental exposures, profoundly influence normal lung function and contribute to the development, progression, and prognosis of various respiratory diseases. Deficiencies in key micronutrients, such as vitamins A, D, and C, as well as omega-3 fatty acids, can impair the integrity of the epithelial lining, compromising the lungs' defense mechanisms and increasing susceptibility to injury and disease. Obesity and physical inactivity further disrupt respiratory function by inducing structural changes in the chest wall and promoting a pro-inflammatory state. Environmental pollutants further worsen oxidative damage and activate inflammatory pathways. Addressing these modifiable factors through interventions such as dietary optimization, physical activity programs, and strategies to reduce environmental exposure offers promising avenues for preserving lung function and preventing disease progression. This review examines the molecular pathways through which nutrition, lifestyle, and environmental influences impact lung homeostasis.