Interaction of renin–angiotensin system and adenosine monophosphate–activated protein kinase signaling pathway in renal carcinogenesis of uninephrectomized rats

Abstract

Renin–angiotensin system and adenosine monophosphate–activated protein kinase signaling pathway both play important roles in carcinogenesis, but the interplay of renin–angiotensin system and adenosine monophosphate–activated protein kinase in carcinogenesis is not clear. In this study, we researched the interaction of renin–angiotensin system and adenosine monophosphate–activated protein kinase in renal carcinogenesis of uninephrectomized rats. A total of 96 rats were stratified into four groups: sham, uninephrectomized, and uninephrectomized treated with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker. Renal adenosine monophosphate–activated protein kinase and its downstream molecule acetyl coenzyme A carboxylase were detected by immunohistochemistry and western blot at 10 months after uninephrectomy. Meanwhile, we examined renal carcinogenesis by histological transformation and expressions of Ki67 and mutant p53. During the study, fasting lipid profiles were detected dynamically at 3, 6, 8, and 10 months. The results indicated that adenosine monophosphate–activated protein kinase expression in uninephrectomized rats showed 36.8% reduction by immunohistochemistry and 89.73% reduction by western blot. Inversely, acetyl coenzyme A carboxylase expression increased 83.3% and 19.07% in parallel to hyperlipidemia at 6, 8, and 10 months. The histopathology of carcinogenesis in remnant kidneys was manifested by atypical proliferation and carcinoma in situ, as well as increased expressions of Ki67 and mutant p53. Intervention with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker significantly prevented the inhibition of adenosine monophosphate–activated protein kinase signaling pathway and renal carcinogenesis in uninephrectomized rats. In conclusion, the novel findings suggest that uninephrectomy-induced disturbance in adenosine monophosphate–activated protein kinase signaling pathway resulted in hyperlipidemia and carcinogenesis in tubular epithelial cells, which may be largely attenuated by renin–angiotensin system blockade, implying the interaction of renin–angiotensin system and adenosine monophosphate–activated protein kinase signaling pathway in renal carcinogenesis of uninephrectomized rats.