Lean in one way, in obesity another: effects of moderate exercise in brown adipose tissue of early overfed male Wistar rats

Fenofibrate treatment during lactation prevents liver and adipose tissue associated metabolic dysfunction in a rat model of childhood obesity

Childhood obesity and associated comorbidities in adulthood are of great concern worldwide. Evidence highlights the importance of lactation in later disease development. In this sense, obese children are at great risk of developing adult obesity, insulin resistance, type 2 diabetes, and cardiovascular disease at adulthood. PPARα activation during lactation promotes the expression of key enzymes involved in lipid oxidation, and it was associated with reduced adiposity in children. Therefore, we hypothesized that an animal model of childhood obesity, small litter (SL), would lead to the development of obesity and metabolic dysfunction in adulthood, which could be prevented by postnatal PPARα agonism. Wistar dams had their litter reduced, leading to postnatal overfeeding and obesity early in life. SL male pups were treated with fenofibrate, an PPARα agonist, during lactation, from postnatal day (PND) 1 until weaning (PND21), to verify whether PPARα activation prevents the developmental programming at adulthood (PND120). Childhood obesity induced by postnatal overfeeding leads to decreased markers for oxidative metabolism during infancy, leading to increased visceral adiposity and oxidative stress, insulin resistance, hepatic microvesicular steatosis, and increased fibroblast growth factor 21 (Fgf21) expression, followed by decreased brown adipose tissue (BAT) sympathetic nerve activity and decreased Fgfr1 hypothalamic expression in adulthood. Agonist-induced PPARα activation during lactation mitigated the development of aforementioned alterations in adulthood. Postnatal fenofibrate treatment prevents the developmental programming of visceral obesity, liver-associated metabolic dysfunction and BAT autonomic sympathetic hypoactivity in an animal model of childhood obesity.

Physical activity and batokines

Brown and beige adipose tissue share similar functionality, being both tissues specialized in producing heat through nonshivering thermogenesis and also playing endocrine roles through the release of their secretion factors called batokines. This review elucidates the influence of physical exercise, and myokines released in response, on the regulation of thermogenic and secretory functions of these adipose tissues and discusses the similarity of batokines actions with physical exercise in the remodeling of adipose tissue. This adipose tissue remodeling promoted by autocrine and paracrine batokines or physical exercise seems to optimize its functionality associated with better health outcomes.

Depot-specific adaption of adipose tissue for different exercise approaches in high-fat diet/streptozocin-induced diabetic mice

Background: Adipose tissue pathology plays a crucial role in the pathogenesis of type 2 diabetes mellitus. Understanding the impact of exercise training on adipose tissue adaptation is of paramount importance in enhancing metabolic health. In this study, we aimed to investigate the effects of various exercise modalities on three distinct adipose tissue depots, namely, interscapular brown adipose tissue (iBAT), subcutaneous white adipose tissue (sWAT), and epididymal white adipose tissue (eWAT), in a murine model of diabetes. Methods: Male C57BL/6J mice received a 12-week high-fat diet and a single injection of streptozotocin, followed by an 8-week exercise intervention. The exercise intervention included swimming, resistance training, aerobic exercise, and high-intensity interval training (HIIT). Results: We found that exercise training reduced body weight and body fat percentage, diminished adipocyte size and increased the expression of mitochondria-related genes (PGC1, COX4, and COX8B) in three adipose tissue depots. The effects of exercise on inflammatory status include a reduction in crown-like structures and the expression of inflammatory factors, mainly in eWAT. Besides, exercise only induces the browning of sWAT, which may be related to the expression of the sympathetic marker tyrosine hydroxylase. Among the four forms of exercise, HIIT was the most effective in reducing body fat percentage, increasing muscle mass and reducing eWAT adipocyte size. The expression of oxidative phosphorylation and thermogenesis-related genes in sWAT and eWAT was highest in the HIIT group. Conclusion: When targeting adipose tissue to improve diabetes, HIIT may offer superior benefits and thus represents a more advantageous choice.

Assessment of Subjective Well-Being in a Cohort of University Students and Staff Members: Association with Physical Activity and Outdoor Leisure Time during the COVID-19 Pandemic

Time spent outdoors and physical activity (PA) promote mental health. To confirm this relationship in the aftermath of COVID-19 lockdowns, we explored individual levels of anxiety, depression, stress and subjective well-being (SWB) in a cohort of academic students and staff members and tested their association with sport practice, PA at leisure time and time spent outdoors. Our cross-sectional study collected data during the COVID-19 outbreak (April−May 2021) on 939 students and on 238 employees, who completed an online survey on sociodemographic and lifestyle features, depression, anxiety, stress, and SWB. Results showed that the students exhibited higher levels of anxiety, depression, and stress, and lower levels of SWB (p < 0.001 for all domains) compared to the staff members. Correlation analysis confirmed that PA and time spent in nature were associated to high mental health scores among staff and, more consistently, among students. Finally, mediation analyses indicated that the time spent in nature, social relationships, and levels of energy play a mediator role in the relationship between sport practice and SWB. Our evidence reinforces the protective role of time spent in nature in improving mental health, and provides support for policymakers to make appropriate choices for a better management of COVID-19 pandemic consequences.

An update on brown adipose tissue and obesity intervention: Function, regulation and therapeutic implications

Overweight and obesity have become a world-wide problem. However, effective intervention approaches are limited. Brown adipose tissue, which helps maintain body temperature and contributes to thermogenesis, is dependent on uncoupling protein1. Over the last decade, an in-creasing number of studies have found that activating brown adipose tissue and browning of white adipose tissue can protect against obesity and obesity-related metabolic disease. Brown adipose tissue has gradually become an appealing therapeutic target for the prevention and re-versal of obesity. However, some important issues remain unresolved. It is not certain whether increasing brown adipose tissue activity is the cause or effect of body weight loss or what the risks might be for sympathetic nervous system-dependent non-shivering thermogenesis. In this review, we comprehensively summarize approaches to activating brown adipose tissue and/or browning white adipose tissue, such as cold exposure, exercise, and small-molecule treatment. We highlight the functional mechanisms of small-molecule treatment and brown adipose tissue transplantation using batokine, sympathetic nervous system and/or gut microbiome. Finally, we discuss the causality between body weight loss induced by bariatric surgery, exercise, and brown adipose tissue activity.