Transplantation of Apoptosis‐Resistant Endothelial Progenitor Cells Improves Renal Function in Diabetic Kidney Disease

BACKGROUND: Diabetic kidney disease is associated with glomerulosclerosis and poor renal perfusion. Increased capillary formation and improved perfusion may help to halt or reverse the injury. Transplanting apoptosis‐resistant p53‐silenced endothelial progenitor cells (p53sh‐EPCs) may help improve vascularization and renal perfusion and could be more beneficial than another stem cell such as the mouse mesenchymal stromal cell (mMSC). METHODS AND RESULTS: Hyperglycemia and proteinuria were confirmed at 8 to 10 weeks in streptozotocin‐induced type1 diabetic C57Bl/6 mice, followed by transplantation of 0.3 million p53sh‐EPCs, Null‐EPCs (control), or mMSC under each kidney capsule. Urine was collected weekly for creatinine and protein levels. Blood pressure was measured by direct arterial cannulation and renal perfusion was measured by renal ultrasound. The kidneys were harvested for histology and mRNA expression. Reduction of protein/creatinine (AUC) was observed in p53sh‐EPC‐transplanted mice more than null‐EPC (1.8‐fold, P=0.03) or null‐mMSC (1.6‐fold, P=0.04, n=4) transplanted mice. Markers for angiogenesis, such as endothelial nitric oxide synthase (1.7‐fold, P=0.06), were upregulated post p53sh‐EPC transplantation compared with null EPC. However, vascular endothelial growth factor‐A expression was reduced (7‐fold, P=0.0004) in mMSC‐transplanted mice, compared with p53sh‐EPC‐transplanted mice. Isolectin‐B4 staining of kidney section showed improvement of glomerular sclerosis when p53sh‐EPC was transplanted, compared with null‐EPC or mMSC. In addition, mean and peak renal blood velocity (1.3‐fold, P=0.01, 1.4‐fold, P=0.001, respectively) were increased in p53sh‐EPC‐transplanted mice, relative to null‐EPC transplanted mice. CONCLUSIONS: Apoptosis‐resistant p53sh EPC transplantation could be beneficial in the treatment of diabetic kidney disease by decreasing proteinuria, and improving renal perfusion and glomerular architecture.