7141 Disruption of Transient Receptor Potential Channel 5 Causes Obesity and Maladaptive Behavior

Abstract Disclosure: Y. Li: None. T. Cacciottolo: None. I.S. Farooqi: None. Y. Xu: None. The global surge in obesity over recent decades poses formidable challenges to public health and economic well-being. Transient Receptor Potential Channel 5 (TRPC5) emerges as a pivotal membrane-spanning cation channel implicated in energy homeostasis, pain modulation, and fear responses. Here, we identified microdeletions on chromosome Xq23 disrupting TRPC5 in boys with food-seeking, obesity, anxiety and autism. Significantly, these microdeletions were inherited from mothers grappling with a constellation of health issues, including obesity and anxiety, suggesting a potential intergenerational aspect to TRPC5-related conditions. We examined approximately 450,000 individuals with exome sequence data from the UK Biobank and found that the TRPC5 gene is the most strongly associated X-linked gene for human body mass index. Moreover, we identified 7 rare TRPC5 variants in patients with severe obesity underscores the potential role of TRPC5 in shaping the obesity phenotype. Functional experiments with HEK293 cells demonstrated that these variants led to a loss of Trpc5 function. Knock-in male mice harboring a human loss-of-function (LOF) TRPC5 variant developed obesity, anxiety, reduced social exploratory behavior and increased aggression; female mice homozygous for the same variant showed similar deficits with reduced severity. We found approximately 91% proopiomelanocortin (Pomc) neurons in arcuate nucleus of the hypothalamus (ARH) express Trpc5 in wild-type male mice. Utilizing the TRPC5 agonist benzothiadiazide derivative (BTD), we found that BTD (i.p., 10 mg/kg) reduced food intake and increased c-Fos expression in Pomc neurons in wild-type mice compared to the vehicle injection group. Importantly, the activation of Trpc5 using BTD did not induce toxicity or aversive effects. Importantly, chemogenetic inactivation using designer receptor exclusively activated by designer drugs (DREADD) of hM4Di-expressing Pomc neurons with clozapine N-oxide (CNO; i.p., 1 mg/kg) effectively blocked BTD-induced anorexia and c-Fos expression in Pomc neurons. Furthermore, we found that BTD-induced anorexia and c-Fos expression in Pomc neurons were blocked in mice with a LOF TRPC5 variant. This suggesting that the effects of BTD on food intake are mediated through Trpc5 in Pomc neurons. In conclusion, our study provides compelling evidence for the involvement of TRPC5 in the intricate regulation of human appetite, body weight, and maladaptive behaviors. Our findings suggest that melanocortin receptor agonists might be effective in treating severe obesity in individuals carrying TRPC5 variants. We suggest that TRPC5 should be included in diagnostic gene panels for severe childhood-onset obesity. Presentation: 6/1/2024