Angiotensin-(1-7) [Ang-(1-7)] is a heptapeptide component of the renin angiotensin system and the endogenous ligand for the Mas receptor. Ang-(1-7) is generated mainly via angiotensin converting enzyme 2 (ACE2)-dependent cleavage of Angiotensin (Ang) II. Studies suggest Ang-(1-7) may protect against progression of renal injury in experimental models of chronic kidney disease, although the responses may be dose dependent. The role of Ang-(1-7) in the progression of renal fibrosis in unilateral ureteral obstruction (UUO) remains unclear. We tested the hypothesis that endogenous Ang-(1-7) and low dose exogenous Ang-(1-7) would protect against renal injury in the UUO model, while high dose Ang-(1-7) would exacerbate renal injury. Male C57Bl/6 mice underwent UUO and received vehicle, the Ang-(1-7) antagonist A779, or one of three doses of Ang-(1-7) for 10 days. Treatment with A779 exacerbated renal injury as seen by increased fibronectin, transforming growth factor-β (TGF-β), and α-smooth muscle actin (α-SMA) expression, increased tubulointerstitial fibrosis scores, macrophage infiltration, apoptosis, and NADPH oxidase activity in obstructed kidneys. Paradoxically, delivery of exogenous Ang-(1-7) was associated with increased renal injury regardless of dose. Taken together, these data indicate the Mas receptor may be sensitive to concentrations of Ang-(1-7) within the obstructed kidney and that exogenous Ang-(1-7) stimulates pro-fibrotic and pro-inflammatory signalling through unclear pathways.

Angiotensin-(1-7) [Ang-(1-7)] is a heptapeptide component of the renin angiotensin system and the endogenous ligand for the Mas receptor. Ang-(1-7) is generated mainly via angiotensin converting enzyme 2 (ACE2)-dependent cleavage of Angiotensin (Ang) II. Studies suggest Ang-(1-7) may protect against progression of renal injury in experimental models of chronic kidney disease, although the responses may be dose dependent. The role of Ang-(1-7) in the progression of renal fibrosis in unilateral ureteral obstruction (UUO) remains unclear. We tested the hypothesis that endogenous Ang-(1-7) and low dose exogenous Ang-(1-7) would protect against renal injury in the UUO model, while high dose Ang-(1-7) would exacerbate renal injury. Male C57Bl/6 mice underwent UUO and received vehicle, the Ang-(1-7) antagonist A779, or one of three doses of Ang-(1-7) for 10 days. Treatment with A779 exacerbated renal injury as seen by increased fibronectin, transforming growth factor-β (TGF-β), and α-smooth muscle actin (α-SMA) expression, increased tubulointerstitial fibrosis scores, macrophage infiltration, apoptosis, and NADPH oxidase activity in obstructed kidneys. Paradoxically, delivery of exogenous Ang-(1-7) was associated with increased renal injury regardless of dose. Taken together, these data indicate the Mas receptor may be sensitive to concentrations of Ang-(1-7) within the obstructed kidney and that exogenous Ang-(1-7) stimulates pro-fibrotic and pro-inflammatory signalling through unclear pathways.

Angiotensin-(1-7) [Ang-(1-7)] is a heptapeptide component of the renin angiotensin system and the endogenous ligand for the Mas receptor. Ang-(1-7) is generated mainly via angiotensin converting enzyme 2 (ACE2)-dependent cleavage of Angiotensin (Ang) II. Studies suggest Ang-(1-7) may protect against progression of renal injury in experimental models of chronic kidney disease, although the responses may be dose dependent. The role of Ang-(1-7) in the progression of renal fibrosis in unilateral ureteral obstruction (UUO) remains unclear. We tested the hypothesis that endogenous Ang-(1-7) and low dose exogenous Ang-(1-7) would protect against renal injury in the UUO model, while high dose Ang-(1-7) would exacerbate renal injury. Male C57Bl/6 mice underwent UUO and received vehicle, the Ang-(1-7) antagonist A779, or one of three doses of Ang-(1-7) for 10 days. Treatment with A779 exacerbated renal injury as seen by increased fibronectin, transforming growth factor-β (TGF-β), and α-smooth muscle actin (α-SMA) expression, increased tubulointerstitial fibrosis scores, macrophage infiltration, apoptosis, and NADPH oxidase activity in obstructed kidneys. Paradoxically, delivery of exogenous Ang-(1-7) was associated with increased renal injury regardless of dose. Taken together, these data indicate the Mas receptor may be sensitive to concentrations of Ang-(1-7) within the obstructed kidney and that exogenous Ang-(1-7) stimulates pro-fibrotic and pro-inflammatory signalling through unclear pathways.

Diabetic kidney disease (DKD) is an emerging pandemic, paralleling the worldwide increase in obesity and diabetes mellitus. DKD is now the most frequent cause of end-stage renal disease and is associated with an excessive risk of cardiovascular morbidity and mortality. DKD is a consequence of systemic endothelial dysfunction. The endothelial-dependent cytoprotective coagulation protease activated protein C (aPC) ameliorates glomerular damage in DKD, in part by reducing mitochondrial ROS generation in glomerular cells. Whether aPC reduces mitochondrial ROS generation in the tubular compartment remains unknown. Here, we conducted expression profiling of kidneys in diabetic mice (wild-type and mice with increased plasma levels of aPC, APChigh mice). The top induced pathways were related to metabolism and in particular to oxidoreductase activity. In tubular cells, aPC maintained the expression of genes related to the electron transport chain, PGC1-α expression, and mitochondrial mass. These effects were associated with reduced mitochondrial ROS generation. Likewise, NLRP3 inflammasome activation and sterile inflammation, which are known to be linked to excess ROS generation in DKD, were reduced in diabetic APChigh mice. Thus, aPC reduces mitochondrial ROS generation in tubular cells and dampens the associated renal sterile inflammation. These studies support approaches harnessing the cytoprotective effects of aPC in DKD.