Therapeutic evaluation of glycoprotein hormone β5/α2 in reducing obesity and metabolic dysfunctions in genetically obese ob/ob mice

Abstract

The escalating obesity epidemic poses serious public health challenges, requiring the development of effective therapeutic strategies. In this study, we aimed to determine if recombinant glycoprotein hormone β5 (GPHB5) protein, particularly in the hybrid form with glycoprotein hormone α2 (GPHA2) (recombinant corticotroph-derived glycoprotein hormone, rCGH), can alleviate obesity in the genetically obese mice, ob/ob. Six-week-old male ob/ob mice were intraperitoneally injected for four weeks with rCGH (10 mg/kg) treatment. Body weight, fat mass and lean mass as well as energy expenditure were evaluated. Blood samples were collected to assess circulating concentrations of triiodothyronine (T3) and thyroxine (T4). Glucose and insulin tolerance tests were also conducted. rCGH significantly decreased body weight and fat mass, stimulated energy expenditure without alterations in food consumption, induced lipolysis and browning of white adipose tissue (WAT) by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway. The treatment with the recombinant protein also led to marked reduction in hepatic steatosis, improved glucose tolerance and insulin sensitivity, and reduced triglycerides (TG), and total cholesterol (T-CHO) levels in ob/ob mice. In conclusion, rCGH attenuated obesity and alleviated metabolic syndromes in ob/ob mice, and it may represent a promising polypeptide-based drug candidate in treating obesity and obesity-related complications without interfering energy intake.