The hypothalamic neuropeptides linked to appetite and satiety were investigated in obese mice treated with cotadutide (a dual receptor agonist of glucagon-like peptide 1 (GLP-1R)/Glucagon (GCGR)). Twe Show more
The hypothalamic neuropeptides linked to appetite and satiety were investigated in obese mice treated with cotadutide (a dual receptor agonist of glucagon-like peptide 1 (GLP-1R)/Glucagon (GCGR)). Twelve-week-old male C57BL/6 mice were fed a control diet (C group, n = 20) or a high-fat diet (HF group, n = 20) for ten weeks. Each group was further divided, adding cotadutide treatment and forming groups C, CC, HF, and HFC for four additional weeks. The hypothalamic arcuate neurons were labeled by immunofluorescence, and protein expressions (Western blotting) for neuropeptide Y (NPY), proopiomelanocortin (POMC), agouti-related protein (AgRP), and cocaine- and amphetamine-regulated transcript (CART). Cotadutide enhanced POMC and CART neuropeptides and depressed NPY and AGRP neuropeptides. In addition, gene expressions (RT-qPCR) determined that Lepr (leptin receptor) and Calcr (calcitonin receptor) were diminished in HF compared to C but enhanced in CC compared to C and HFC compared to HF. Besides, Socs3 (suppressor of cytokine signaling 3) was decreased in HFC compared to HF, while Sst (somatostatin) was higher in HFC compared to HF; Tac1 (tachykinin 1) and Mc4r (melanocortin-4-receptor) were lower in HF compared to C but increased in HFC compared to HF. Also, Glp1r and Gcgr were higher in HFC compared to HF. In conclusion, the findings are compelling, demonstrating the effects of cotadutide on hypothalamic neuropeptides and hormone receptors of obese mice. Cotadutide modulates energy balance through the gut-brain axis and its associated signaling pathways. The study provides insights into the mechanisms underlying cotadutide's anti-obesity effects and its possible implications for obesity treatment. Show less
The study was conducted to understand better the mechanisms involved in liver changes when there is a combination of diet-induced obesity (DIO) and vitamin D deficiency (VDD). After 8 wk of feeding a Show more
The study was conducted to understand better the mechanisms involved in liver changes when there is a combination of diet-induced obesity (DIO) and vitamin D deficiency (VDD). After 8 wk of feeding a control diet (C group) or a high-fat diet (HF), both with vitamin D, and counterpart groups without vitamin D (VitD- groups), we found in plasma: higher alanine aminotransferase, and aspartate aminotransferase in the VitD- groups, and more elevated total cholesterol in the HF group. Compared to their counterparts, HF and HF/VitD- showed hyperinsulinemia and higher hepatic triglycerides and steatosis. The protein expressions of markers linked with the vitamin D action were altered by VDD (vitamin D receptor VDR, 25-hydroxyvitamin D-24-hydroxylase CYP24A1, CYP27B1, and CYP2R1). The hepatic lipogenesis and fatty acid synthesis were enhanced by VDD (peroxisome proliferator-activated receptor PPARγ, sterol regulatory element-binding proteins SREBP1c, carbohydrate-responsive element-binding protein ChREBP, and fatty acid synthase FAS), but markers of beta-oxidation were reduced (PPARα and phosphoenolpyruvate carboxykinase PEPCK). In conclusion, the study provides convincing new evidence that there is an additive and adverse effect on the liver caused by the combination of VDD and DIO. The essence of these changes in the liver is in an increased lipogenesis and a reduced beta-oxidation, which predisposes to the accumulation of fat in the liver, accompanied by IR. The worsening of the pathogenesis of NAFLD may tilt to more severe stages of liver disease. Show less