gyy-4137 and Ureteral-Obstruction

In prolonged complete unilateral ureteral obstruction, reduced renal blood flow places the kidney in a state of ischemia, which can cause tubular injury and inflammation. Infiltrating inflammatory cells release transforming growth factor beta 1, which is a cytokine that initiates fibrosis through the epithelial-mesenchymal-transition pathway. Persistent fibrosis can lead to irreversible renal injury and loss of function. While surgical intervention can remove the obstruction, relief of obstruction may not fully reverse renal injury. Additionally, patients often encounter long wait-times between initial consultation and medical intervention, resulting in the accumulation of renal injury that may cause permanent dysfunction. Currently, accepted pharmacological therapies to mitigate the symptoms of ureteral obstruction include acetaminophen, cyclooxygenase-inhibitors, non-steroidal anti-inflammatory medications, opioids and alpha-receptor blockers. However, there is no evidence that they mitigate renal injury. Therefore, identifying potential therapies that could be administered during obstruction may help to improve renal function following decompression. Evidence suggests that endogenously produced gasotransmitters can exhibit anti-inflammatory and antioxidant effects. Nitric oxide, carbon monoxide, and hydrogen sulfide have been identified as gasotransmitters and have been shown to have cytoprotective effects in various models of tissue injury. Studies have shown that treatment with sodium hydrogen sulfide (a hydrogen sulfide donor salt) mitigated transforming growth factor beta 1 expression, oxidative stress, fibrosis, and inflammation associated with urinary obstruction. More recently, the use of more directed hydrogen sulfide donor molecules, such as GYY4137, has led to significant decreases in inflammation, fibrosis, and expression of epithelial mesenchymal transition markers following urinary obstruction. Taken together, these findings suggest that hydrogen sulfide may be a novel potential therapy against renal injury caused by urinary obstruction. This review will highlight the existing literature about the pathogenesis and treatment of renal damage caused by chronic urinary obstruction and propose novel upcoming strategies that could improve patient outcomes.

Topics: Animals; Carbon Monoxide; Disease Models, Animal; Fibrosis; Gasotransmitters; Humans; Hydrogen Sulfide; Kidney; Male; Morpholines; Nitric Oxide; Organothiophosphorus Compounds; Ureteral Obstruction

To assess the effects of slow-releasing H. Male Lewis rats underwent UUO at the left ureterovesical junction. From post-operative day (POD) 1-13, rats received daily intraperitoneal (IP) injection of phosphate buffered saline (PBS, 1 mL) or GYY4137 (200 μmol/kg/day in 1 mL PBS, IP). On POD 14, the ureter was reimplanted back into the bladder, followed by a right nephrectomy. Urine and serum samples were collected to monitor renal function. On POD 30, the left kidney was removed and tissue sections were stained with H&E, TUNEL, CD68, CD206, myeloperoxidase, and Masson's trichrome to determine cortical thickness, apoptosis, inflammation, and fibrosis. In our in vitro model of EMT, NRK52E cells were treated with 10 ng/mL TGF-β1, 10 μM GYY4137 and/or 50 μM GYY4137. Western blot analysis was performed to determine the expression of E-cadherin, vimentin, Smad7 and TGF-β1 receptor II (TβRII).. GYY4137 led to a moderate decrease in post-obstructive serum creatinine, cystatin C and FENa. We also observed a trend towards a decrease in post-obstructive proteinuria following GYY4137 treatment. Histologically, we observed a significant decrease in apoptosis, inflammation, and fibrosis. Furthermore, our in vitro studies demonstrate that in the presence of TGF-β1, GYY4137 significantly decreases vimentin and TβRII and significantly increases E-cadherin and Smad7.. H

Topics: Animals; Kidney; Kidney Diseases; Male; Morpholines; Organothiophosphorus Compounds; Rats; Rats, Inbred Lew; Ureteral Obstruction

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). H. 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.. H. To our knowledge our findings demonstrate for the first time the protective effects of H

Topics: Animals; Chronic Disease; Hydrogen Sulfide; Kidney Diseases; Male; Morpholines; Organothiophosphorus Compounds; Rats; Rats, Inbred Lew; Swine; Ureteral Obstruction