Search

Diabetic nephropathy is one of the most common complications that is related to high morbidity and mortality in type 2 diabetic patients. We investigated ability of a novel dual modulator, PTUPB that concurrently acts as a soluble epoxide hydrolase inhibitor and as a cyclooxygenase-2 inhibitor against diabetic nephropathy. Sixteen week-old type 2 diabetic and proteinuric obese ZSF1 rats were treated with vehicle, PTUPB, or enalapril for 8 weeks. Obese ZSF1 rats were diabetic with 5-fold higher fasting blood glucose levels and markedly higher HbA1c levels compared to lean ZSF1 rats. Neither PTUPB nor enalapril reduced fasting blood glucose or HbA1c in obese ZSF1 rats. The obese ZSF1 rats also developed diabetic nephropathy with elevated albuminuria and tubular and glomerular injuries. PTUPB alleviated diabetic nephropathy in obese ZSF1 rats by reducing albuminuria by 50%, renal cortical and medullary cast formation by 60–70%, renal fibrosis by 40–50%, and glomerular injury by 55%. In PTUPB treated obese ZSF1 rats, glomerular nephrin expression was preserved. Enalapril treatment demonstrated an effect comparable to PTUPB and alleviated diabetic nephropathy in obese ZSF1 rats by reducing all kidney injury parameters by 30 to 50%. Diabetic renal injury in obese ZSF1 rats was accompanied by renal inflammation with 6–7fold higher urinary MCP-1 level and renal infiltration of CD-68 positive cells. PTUPB and enalapril treatment reduced renal inflammation with significantly reduced urinary MCP-1 levels and renal mRNA expression of cytokines. PTUPB demonstrated superior anti-inflammatory actions compared to enalapril treatment. Obese ZSF1 rats were also hypertensive, hyperlipidemic, and exhibited liver injury. Both PTUPB and enalapril lowered blood pressure in obese ZSF1 rats. Interestingly, PTUPB but not enalapril decreased hyperlipidemia and liver injury in Obese ZSF1 rats. Overall, we demonstrate that a dual modulator PTUPB does not treat hyperglycemia, but can effectively alleviate hypertension, diabetic nephropathy, hyperlipidemia and liver injury in type 2 diabetic rats. Our data further demonstrate that the renal actions of PTUPB is comparable to a current standard diabetic nephropathy treatment.

Kidney fibrosis is a key event in the development of chronic kidney disease, leading to end-stage renal failure. Unfortunately, there are now few drugs capable of preventing fibrosis in the kidneys, which is accompanied by the progression of chronic kidney disease in the terminal stage of renal failure. The results show the effectiveness of the use of a new dual-acting agent DM509 in the prevention of renal fibrosis using a model of unilateral obstruction of the ureter in mice. DM509 is both a farnesoid X-receptor agonist and a soluble epoxyhydrolase inhibitor. In this study, there were 8-12 week old C57BL/6J males undergoing surgery, which led to the development of unilateral ureteral obstruction and a control group. Mice received DM509 (10 mg/kg/day) or DM509-free solution together with drinking water for 10 days the day before surgery. Samples of kidney and blood tissues were collected at the end of the experiment. In the unilateral ureteral obstruction group, kidney dysfunction was detected, which was accompanied by increased urea nitrogen content in the blood compared to the control group (63 ± 7 vs. 34 ± 6 mg/d). The reduction of urea nitrogen in the blood by 36 % in mice with unilateral ureteral obstruction treated with DM509 is shown compared to mice with this pathology without treatment, which in turn proved the effectiveness of DM509 in preventing renal dysfunction. In mice with unilateral ureteral obstruction, which did not receive DM509, the development of kidney fibrosis with a high content of hydroxyproline in the kidneys and also increased collagen content in histological sections of the kidneys were detected. In the DM509 group, the renal and collagen hydroxyproline content was 34-66 % lower, indicating the effectiveness of this agent in the treatment of renal fibrosis. Thus, we have shown that the new DM509 is effective in preventing renal dysfunction and renal fibrosis using a murine model of unilateral ureteral obstruction.

Background and Purpose: Diabetic nephropathy is one of the most common complications that is related to high morbidity and mortality in type 2 diabetic patients. We investigated ability of a novel dual modulator, PTUPB that concurrently acts as a soluble epoxide hydrolase inhibitor and as a cyclooxygenase-2 inhibitor against diabetic nephropathy. Experimental Approach: Sixteen-week-old type 2 diabetic and proteinuric obese ZSF1 rats were orally treated with vehicle, PTUPB, or enalapril for 8 weeks. Key Results: PTUPB alleviated diabetic nephropathy in obese ZSF1 rats by reducing albuminuria by 50%, renal tubular cast formation by 60-70%, renal fibrosis by 40-50%, glomerular injury by 55% and preserved glomerular nephrin expression. Enalapril demonstrated comparable effects and alleviated diabetic nephropathy in obese ZSF1 rats by reducing all kidney injury parameters by 30 to 50%. Diabetic renal injury in obese ZSF1 rats was accompanied by renal inflammation with 6-7-fold higher urinary MCP-1 level and renal infiltration of CD-68 positive cells. PTUPB and enalapril reduced renal inflammation but PTUPB demonstrated superior anti-inflammatory actions than enalapril. Obese ZSF1 rats were also hypertensive, hyperlipidemic, and exhibited liver injury. Interestingly, PTUPB but not enalapril decreased hyperlipidemia and liver injury in Obese ZSF1 rats. Conclusion and Implication: Overall, we demonstrate that a dual modulator PTUPB does not treat hyperglycemia, but can effectively alleviate hypertension, diabetic nephropathy, hyperlipidemia, and liver injury in type 2 diabetic rats. Therefore, we suggest that PTUPB has promising potential to be developed as a novel therapy for type 2 diabetic nephropathy and other complications.

Renal fibrosis is a contributor to chronic kidney disease and an important predictor of long-term prognosis. We developed a dual soluble epoxide hydrolase inhibitor-PPAR-γ agonist (sEHi/PPAR-γ), RB394, and investigated its ability to attenuate renal fibrosis in a mouse unilateral ureteral obstruction (UUO) model. RB394 efficacy was compared to an sEH inhibitor (sEHi), a PPAR-γ agonist rosiglitazone (Rosi), or their combination (sEHi + Rosi). All interventional treatments were administrated in drinking water 3 days after UUO induction surgery and continued for 7 days. UUO mice developed renal fibrosis with higher collagen formation and RB394 significantly attenuated fibrosis (P < 0.05). Renal expression of α-smooth muscle actin (α-SMA) was elevated in UUO mice and all treatments except sEHi significantly attenuated renal α-SMA expression. Renal mRNA expression fibrotic and fibrosis regulators were higher in UUO mice and RB394 and sEHi + Rosi treatments attenuated their expression. Renal inflammation was evident in UUO mice with increased infiltration of CD45 and F4/80 positive cells. RB394 and sEHi + Rosi treatments attenuated renal inflammation in UUO mice. UUO mice had renal tubular and vascular injury. Renal tubular and vascular injuries were attenuated to a greater extent by RB394 and sEHi + Rosi than sEHi or Rosi treatment alone. Renal mRNA expression of oxidative stress markers were significantly higher in UUO mice (P < 0.05). RB394 and sEHi + Rosi attenuated expression of oxidative stress markers to a greater extent than other interventional treatments (P < 0.05). These findings demonstrate that RB394 can attenuate renal fibrosis by reducing renal inflammation, oxidative stress, tubular injury, and vascular injury. In conclusion, RB394 demonstrates exciting potential as a therapeutic for renal fibrosis and chronic kidney disease.