Renal-Derived Human sPRR Does Not Increase Blood Pressure in High Fat Diet Mice

Abstract

Obesity is a risk factor for hypertension. Obesity-related hypertension has been associated with elevated plasma soluble prorenin receptor (sPRR) particularly in men. Additionally, renal PRR and sPRR protein expression is upregulated during obesity and diabetes. However, whether renal-derived human sPRR (HsPRR) may influence the intrarenal RAS status to regulate blood pressure and kidney function during obesity has not been investigated. Therefore, we studied the role of collecting duct (CD) derived-HsPRR on blood pressure and kidney function in male and female mice during obesity. Eight-week-old male and female CD-HsPRR mice were placed on a high fat diet for 25 weeks. HsPRR increased renal sPRR concentration but did not change its circulating levels in male and female littermates compared to CTL mice. GFR, water intake and urine flow were not influenced by the CD-HsPRR expression in either sex. Moreover, after 21 weeks of HFD, blood pressure was similar between groups, while only male CD-HsPRR mice showed an impaired pressor response to losartan. In the renal cortex, male CD-HsPRR mice showed increased renin and AT1R mRNA expression associated with increased AQP2, and ENaC subunits protein expression. These data indicate that renal-derived HsPRR induces local upregulation in renin, AT1R and sodium/water transporters in male mice without altering renal hemodynamics or blood pressure. In obese females, CD-HsPRR expression did not affect blood pressure or renal function, which suggests that females may be protected from obesity induced renal function impairment and hypertension.