EP₁ receptor antagonism mitigates early and late stage renal fibrosis

Abstract

Aim Renal fibrosis is a major driver of chronic kidney disease, yet current treatment strategies are ineffective in attenuating fibrogenesis. The cyclooxygenase/prostaglandin system plays a key role in renal injury and holds great promise as a therapeutic target. Here, we used a translational approach to evaluate the role of the PGE2‐EP1 receptor in the pathogenesis of renal fibrosis in several models of kidney injury, including human (fibrotic) kidney slices. Methods The anti‐fibrotic efficacy of a selective EP1 receptor antagonist (SC‐19220) was studied in mice subjected to unilateral ureteral obstruction (UUO), healthy and fibrotic human precision‐cut kidney slices (PCKS), Madin‐Darby Canine Kidney (MDCK) cells and primary human renal fibroblasts (HRFs). Fibrosis was evaluated on gene and protein level using qPCR, western blot and immunostaining. Results EP1 receptor inhibition diminished fibrosis in UUO mice, illustrated by a decreased protein expression of fibronectin (FN) and α‐smooth muscle actin (αSMA) and a reduction in collagen deposition. Moreover, treatment of healthy human PCKS with SC‐19220 reduced TGF‐β‐induced fibrosis as shown by decreased expression of collagen 1A1, FN and αSMA as well as reduced collagen deposition. Similar observations were made using fibrotic human PCKS. In addition, SC‐19220 reduced TGF‐β‐induced FN expression in MDCK cells and HRFs. Conclusion This study highlights the EP1 receptor as a promising target for preventing both the onset and late stage of renal fibrosis. Moreover, we provide strong evidence that the effect of SC‐19220 may translate to clinical care since its effects were observed in UUO mice, cells and human kidney slices.

An animal-free preclinical drug screening platform based on human precision-cut kidney slices

“…1 C and D). These results support the notion that prostaglandin E 2 receptors are potential targets for the treatment of renal fibrosis, in line with previous findings [ 5 , 6 , 11 ]. As shown in Fig.…”

“…Our results demonstrated that butaprost, SC-19220 and tamoxifen altered TGF-β-induced pro-fibrotic gene expression in human PCKS, in line with previous studies from our lab [5][6][7]. Moreover, this study revealed that it is feasible to use an animal-free approach to test drug efficacy and elucidate mechanisms of action.…”

“…We have previously demonstrated that butaprost, SC-19220 and tamoxifen can attenuate collagen deposition in rodents subjected to unilateral ureteral obstruction [5][6][7]. Therefore, we now evaluated the impact of all three compounds on the protein expression of FN and αSMA, two well-known markers of activated collagen-producing myofibroblasts [10], in human PCKS.…”

“…During experiments, the slices were treated for 48 h with 10 ng/ml recombinant human transforming growth factor-β1 (TGF-β; H8541, Sigma-Aldrich) in the absence or presence of butaprost (50 µM; a selective prostaglandin E 2 [PGE 2 ] EP 2 receptor agonist; 13741, Cayman), SC-19220 (225 µM; a selective PGE 2 EP 1 receptor antagonist; S3065, Sigma-Aldrich) or tamoxifen (5 nM; a selective estrogen receptor modulator; T5648, Sigma-Aldrich). Of note, tamoxifen was only present during the final 6 h. We have previously demonstrated the anti-fibrotic activity of these compounds using celland animal models as well as human PCKS [5][6][7].…”

Prolyl hydroxylase inhibitors, polydrug use, and the phosphoproteome

“…Development of treatment strategies for kidney diseases largely relies on experimental models of ureteral obstruction/tubular-interstitial fibrosis, 1,2 acute kidney injury/ ischemia/reperfusion, 3,4 cyclosporine toxicity 5,6 or diabetic nephropathy. 7 However, experimental models only partly replicate the respective human disease.…”