Adropin mitigates reproductive and metabolic dysfunctions in streptozotocin induced hyperglycemic mice

Abstract

Hyperglycemia is the predominant endocrine and metabolic disorder, resulting in infertility in males. Adropin, a hepatokine, is a well-known insulin sensitizer that regulates glucose and lipid homeostasis. Our recent reports demonstrated the vital role of adropin in the regulation of testicular activity, but its role in testicular function during pathological conditions such as hyperglycemia has not yet been studied. Therefore, this study aimed to explore the effect of adropin treatment on reproductive and metabolic dysfunctions in hyperglycemic mice. Hyperglycemia was induced by streptozotocin (55 mg/kg body weight; i.p.) treatment followed by treatment with either adropin (450 nmol/kg body weight; i.p.) or metformin (500 mg/kg body weight; orally) for a period of 15 days. Treatment of hyperglycemic mice enhanced insulin sensitivity by increasing insulin receptor expression in the testis and decreasing HOMA-IR and circulating glucose level. Adropin treatment of hyperglycemic mice increased the production of testicular testosterone by promoting the expression of steroidogenic proteins. Moreover, adropin treatment also enhanced the proliferation and survival of testicular germ cells by increasing PCNA expression and decreasing BAX/Bcl2 ratio and TUNEL-positive cells in the testis of hyperglycemic mice. Flow cytometric analysis revealed an increased number of advanced germ cells in adropin-treated hyperglycemic mice. Notably, adropin treatment was more effective than metformin in restoring reproductive functions in hyperglycemic mice, as evidenced by the reestablishment of the testicular histoarchitecture and increased synthesis of testosterone in the testes. These findings suggest that adropin may serve as a viable therapeutic alternative to mitigate hyperglycemia-associated testicular dysfunction.

Keywords: GPR19; adropin; hyperglycemia; insulin resistance; spermatogenesis; steroidogenesis.