GYY4137, a Slow-Releasing Hydrogen Sulfide Donor, Ameliorates Renal Damage Associated with Chronic Obstructive Uropathy.

Abstract

Chronic obstructive uropathy can cause irreversible kidney injury, atrophy and inflammation, which can ultimately lead to fibrosis. Epithelial-mesenchymal transition is a key trigger of fibrosis that is caused by up-regulation of TGF-β1 (transforming growth factor-β1) and ANGII (angiotensin II). H₂S is an endogenously produced gasotransmitter with cytoprotective properties. We sought to elucidate the effects of the slow-releasing H₂S donor GYY4137 on chronic ureteral obstruction and evaluate the potential mechanisms. Following unilateral ureteral obstruction male Lewis rats were given daily intraperitoneal administration of phosphate buffered saline vehicle (obstruction group) or phosphate buffered saline plus 200 μmol/kg GYY4137 (obstruction plus GYY4137 group) for 30 days. Urine and serum samples were collected to determine physiological parameters of renal function and injury. Kidneys were removed on postoperative day 30 to evaluate histopathology and protein expression. Epithelial-mesenchymal transition in LLC-PK1 pig kidney epithelial cells was induced with TGF-β1 and treated with GYY4137 to evaluate potential mechanisms via in vitro scratch wound assays. H₂S treatment decreased serum creatinine and the urine protein-to-creatinine excretion ratio after unilateral ureteral obstruction. In addition, H₂S mitigated cortical loss, inflammatory damage and tubulointerstitial fibrosis. Tissues showed decreased expression of epithelial-mesenchymal transition markers upon H₂S treatment. Epithelial-mesenchymal transition progression in LLC-PK1 was alleviated upon in vitro administration of GYY4137. To our knowledge our findings demonstrate for the first time the protective effects of H₂S in chronic obstructive uropathy. This may represent a potential therapeutic solution to ameliorate renal damage and improve the clinical outcomes of urinary obstruction.