Abstract: TH-OR134

Genetic Ablation of Vasohibin-2 Prevents the Progression of Diabetic Nephropathy in an Experimental Mouse Model

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Masuda, Kana, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Tanabe, Katsuyuki, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Ujike, Haruyo, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Hinamoto, Norikazu, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Miyake, Hiromasa, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Sugiyama, Hitoshi, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Maeshima, Yohei, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
  • Wada, Jun, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama, Japan
Background

Diabetic nephropathy has been reported to be associated with abnormal angiogenesis and increased glomerular VEGF, which could represent potential therapeutic targets. Vasohibin-2 (VASH2) is a novel pro-angiogenic factor and has shown to be involved in tumor enlargement. In the present study, we investigated whether VASH2 was involved in the progression of diabetic nephropathy in vivo and in vitro experiments.

Methods

Eight to ten weeks old male C57BL/6 wild type (WT) or VASH2-knockout (VASH2LacZ/LacZ) mice received intraperitoneal injections of 50mg/kg STZ or vehicle on five consecutive days. The experimental subgroups included 1) non-diabetic WT, 2) non-diabetic VASH2LacZ/LacZ, 3) diabetic WT and 4) diabetic VASH2LacZ/LacZ. Blood glucose (BG) and urine albumin excretion (UAE) were evaluated every other week, and 16 weeks after the injections, blood pressure (BP) was measured and blood and kidney samples were obtained. Conditionally immortalized human mesangial cells were stimulated by high glucose (25mM) or TGF-β1 (10 ng/ml) under the presence of control or VASH2 siRNA.

Results

There were no differences in BP, BG and serum creatinine between diabetic WT and VASH2LacZ/LacZ group. However, increased UAE and creatinine clearance observed in diabetic WT mice were significantly decreased in diabetic VASH2LacZ/LacZ mice. In addition, increased glomerular CD31 positive area induced by diabetes was also suppressed in VASH2LacZ/LacZ group. VASH2 deficiency did not affect renal level of VEGF but suppressed diabetes-induced elevation of renal VEGFR2 expression. Increased glomerular type IV collagen accumulation and renal TGF-β1 mRNA in diabetic WT mice were prevented in diabetic VASH2LacZ/LacZ mice. Endogenous VASH2 level was increased by diabetes, and immunostaining suggested that VASH2 was localized in mesangial cells in glomeruli. Knockdown of VASH2 using siRNA suppressed the increased mRNA level of type IV collagen and α-SMA in cultured mesangial cells treated with high glucose or TGF-β1 stimulation.

Conclusion

Deletion of VASH2 had protective effects in diabetic nephropathy through the suppression of excessive VEGF action on endothelial cells and extracellular matrix production in mesangial cells.