Project description:Antipsychotic drugs (APs) are used to treat psychiatric disorders but also have the prominent side effect of weight gain resulting in a higher incidence of metabolic disease in this patient group. While the majority of patients gain significant weight in response to APs some patients are relatively resistant to these effects. APs such as clozapine and olanzapine are deemed to be highly efficacious at treating psychiatric conditions yet they have some of the highest weight gain liabilities. Therefore, there is a need to determine which patients are less susceptible to the metabolic side effects of APs and would be good candidates for drugs such as olanzapine, and conversely, identifying patients that should be prescribed alternative APs with less weight gain liabilities.
Project description:Experimental overfeeding triggers homeostatic compensatory mechanisms that counteract weight gain. Here, we utilized intragastric overfeeding in mice to investigate the physiological and molecular responses to forced weight gain. Both lean and diet-induced obese (DIO) mice exhibited a potent and prolonged lowering of voluntary food intake following overfeeding-induced weight gain. Although overfeeding resulted in a marked increase in circulating fibroblast growth factor 21 (FGF21), experiments with FGF21 knockout (KO) mice demonstrated that FGF21 is dispensable for the homeostatic defense against experimental weight gain. Targeted proteomics unveiled novel circulating factors linked to overfeeding, including the protease legumain (LGMN). Notably, administration of recombinant LGMN lowered body weight and food intake in DIO mice. The protection against weight gain was also associated with reduced vascularization in the hypothalamus and sustained reductions in transcript levels of the orexigenic neuropeptides, Npy and AgRP, suggesting a role of hypothalamic signaling in the homeostatic recovery from overfeeding. Overfeeding of melanocortin 4 receptor (MC4R) KO mice showed that these mice can suppress voluntary food intake and counteract the enforced weight gain, although their rate of weight recovery is impaired. Collectively, these findings demonstrate that the defense against overfeeding-induced weight gain remains intact in obesity and involves mechanisms independent of both FGF21 and MC4R.
Project description:The aim of this study was to investigate the association of gene expression profiles in subcutaneous adipose tissue with percent of total body weight change in 26 kidney transplant recipients. Using multivariate linear regression analysis controlled for race and gender, expression levels of 1553 genes were significantly (p<0.05) associated with weight change. A secondary data analysis was done on a subgroup (n=26) of existing clinical and gene expression data from a larger prospective longitudinal study examining factors contributing to weight gain in transplant recipients.
Project description:Calorie restriction (CR) and fasting are common approaches to weight reduction, but the maintenance is difficult after resuming food consumption. Meanwhile, the gut microbiome associated with energy harvest alters dramatically in response to nutrient deprivation. Here, we reported that CR and high-fat diet (HFD) both remodeled the gut microbiota with similar microbial composition. Parabacteroides distasonis was most significantly decreased after CR or HFD. CR altered microbiota and reprogramed metabolism, resulting in a distinct serum bile acid profile characterized by depleting the proportion of non-12α-hydroxylated bile acids, ursodeoxycholic acid and lithocholic acid. Downregulation of UCP1 expression in brown adipose tissue and decreased serum GLP-1 were observed in the weight-rebound mice. Moreover, treatment with Parabacteroides distasonis or non-12α-hydroxylated bile acids ameliorated weight regain via increased thermogenesis. Our results highlighted the gut microbiota- bile acid crosstalk in rebound weight gain and Parabacteroides distasonis as a potential probiotic to prevent rapid post-CR weight gain.
