Varredura e caracterização de moléculas circulantes que afetam o gasto energético

Abstract

The prevalence of obesity has been growing worldwide alongside its comorbidities. Current anti-obesity therapies appear to be poorly efficient, especially on the long-term, and are associated with significant side effects. There are two ways to lose weight: by decreasing energy intake or increasing energy expenditure. One way to increase energy expenditure in mammals is through the stimulation of brown/beige adipocytes and the increase in their function. This phenomenon correlates with high levels of UCP1 expression and activity. Some conditions capable of regulating UCP1 expression and function have already been described. Among them, there is chronic cold exposure, exercise, an enriched social environment, and cancer cachexia. These conditions act through cell autonomous mechanisms, such as by regulating transcription factors in preadipocytes or adipocytes, and cell non-autonomous mechanisms, such as by signaling through hormones and other circulating molecules. The study and understanding of the circulating molecules that act in adipose tissue to increase its brown/beige characteristics is essential for the development of more efficient and secure pharmacological strategies that could help to mitigate the global scenario of obesity. We observed, based on our preliminary results, that serum of mice subjected to dietary restriction modulates the expression of Ucp1 in vitro in mouse adipocytes derived from brown adipose tissue. This seems to be due to one or more circulating molecules present in the serum of ad libitum-fed individuals that induce UCP1 in a dose-dependent manner. These molecules are absent or very low in serum of DR-subjected individuals. Interestingly, this effect can be reproduced using serum of rats or obese humans subjected to bariatric surgery. We aim to find these circulating molecules that are likely proteins or protein-dependent molecules. This/these molecule(s) may bring insights into the development of new drugs to combat obesity.