Abstract: TH-PO712

Agonistic Anti-CD148 Monoclonal Antibody Attenuates Diabetic Nephropathy in Mice

Session Information

Category: Diabetes

  • 501 Diabetes Mellitus and Obesity: Basic - Experimental

Authors

  • Takahashi, Keiko, Vanderbilt University, Nashville, Tennessee, United States
  • Kim, Rachel H., Vanderbilt University, Nashville, Tennessee, United States
  • Nagasaka, Shinya, Vanderbilt University, Nashville, Tennessee, United States
  • Katagiri, Daisuke, Vanderbilt University, Nashville, Tennessee, United States
  • Mernaugh, Ray, Vanderbilt University, Nashville, Tennessee, United States
  • Takahashi, Takamune, Vanderbilt University, Nashville, Tennessee, United States
Background

CD148 is a transmembrane protein tyrosine phosphatase (PTP) that is expressed in renal vasculature, including glomerular endothelial cells and podocytes. Previous studies have shown that CD148 suppresses multiple growth factor signaling pathways (e.g. VEGF, EGF) and prominently inhibits endothelial or epithelial cell proliferation. Here, we have generated an agonistic anti-CD148 monoclonal antibody (18E1) and evaluated its effects in murine diabetic nephropathy.

Methods

Monoclonal antibodies (mAbs) against mouse CD148 ectodomain (CD148ecto) were produced by immunizing CD148 -/- mice with CD148ecto-Fc fusion protein. The mAbs that specifically bind to CD148 and increase its catalytic activity and inhibit the proliferation of CD148 stably- transfected cells were selected by a series of biochemical (Western blot, PTP activity) and biological (proliferation) assays. The specificity of the effects was evaluated by CD148 knockdown or knockout. The mAb (18E1) that showed strong agonistic activity was injected (10 mg/kg, i.p., three times per week) into wild-type (WT) and CD148 -/- (KO) diabetic mice (DBA2 strain, 8 week-old, N=6 per group) for 6 weeks, then renal phenotype was assessed. Diabetes was induced by low-dose STZ injections and mouse IgG was used as a control. Furthermore, the effects of 18E1 mAb in glomerular endothelial cell and podocyte cell proliferation were also assessed in culture.

Results

As compared with control Ab, the 18E1 mAb significantly decreased albuminuria (~50%) and mesangial expansion (~30%) without altering hyperglycemia and blood pressure in WT diabetic mice. Immunohistochemical evaluation showed that the 18E1 mAb significantly prevents the reduction of podocyte number and nephrin expression and decreases glomerular macrophage (F4/80) infiltration (~40%) and matrix expansion (fibronectin) (~30%). The 18E1 mAb showed no effects in CD148KO diabetic mice. In addition, the 18E1 mAb significantly (~50%) inhibited proliferation of glomerular endothelial cells and podocytes in culture concomitant with reduction of VEGFR2 or EGFR phosphorylation. These inhibitory effects were largely abolished by CD148 knockdown.

Conclusion

Agonistic anti-CD148 antibody attenuates diabetic nephropathy in mice. Anti-CD148 antibody may be used as a new therapeutic agent for the treatment of early phase diabetic nephropathy.

Funding

  • NIDDK Support