(2s-3as-7as)-1-(((r-r)-2-phenylcyclopropyl)carbonyl)-2-((thiazolidin-3-yl)carbonyl)octahydro-1h-indole and Kidney-Diseases

Angiotensin-converting enzyme inhibitors (ACEi) are widely used to deter the progression of chronic kidney disease (CKD). Besides controlling hypertension and reduction of intra-glomerular pressure, ACEi appear to have anti-fibrotic effects in the renal cortex. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), an endogenous tetrapeptide that is degraded by ACE, has also been shown to ameliorate the pro-fibrotic phenotype displayed in CKD in our recent study. Whether the anti-fibrotic properties of ACEi are mediated by Ac-SDKP has not been fully investigated.. To delineate the role of Ac-SDKP in ACE blockade, 12-week-old male BALB/c mice underwent sham operation or unilateral ureteric obstruction (UUO). UUO mice were subjected to: (i) vehicle; (ii) captopril or (iii) captopril in conjunction with S17092, a prolyl oligopeptidase inhibitor. After 7 days, mice were sacrificed and kidneys harvested for analyses.. After UUO, there were heightened expressions of collagen I, collagen III, fibronectin and α-SMA associated with significant levels of tubulointerstitial injury on histological examination. Furthermore, p44/42 mitogen-activated protein kinase (MAPK) and transforming growth factor beta 1(TGF-β1) signalling were upregulated. These were significantly ameliorated by captopril treatment alone but unaffected by co-administration of captopril with S17092. Captopril treatment had resulted in elevated urinary Ac-SDKP levels, an effect that was eliminated by the co-administration with S17092.. This study allowed the investigation of the renoprotective property of ACEi in the absence of Ac-SDKP and proved conclusively that Ac-SDKP is the prime anti-fibrotic mediator of captopril, acting via p44/42 MAPK and TGF-β1 signalling pathways. Future research to expand CKD armamentarium should explore the utility of augmenting Ac-SDKP levels.

Topics: Angiotensin-Converting Enzyme Inhibitors; Animals; Captopril; Disease Models, Animal; Extracellular Matrix Proteins; Fibrosis; Indoles; Kidney; Kidney Diseases; Male; Mice, Inbred BALB C; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Oligopeptides; Peptidyl-Dipeptidase A; Prolyl Oligopeptidases; Serine Endopeptidases; Serine Proteinase Inhibitors; Signal Transduction; Thiazolidines; Transforming Growth Factor beta1; Ureteral Obstruction