Efficacy of Repeated Administration of Cultured Human CD34+ Cells Against Streptozotocin-Induced Diabetic Nephropathy in Rats

To date, no clinical trial has investigated the potential of CD34⁺ cells to treat diabetic nephropathy. This study examined the efficacy of human CD34⁺ cells against diabetic nephropathy in rats. Rats were administered streptozotocin (STZ) intraperitoneally and divided into three groups: normal control, STZ control, and STZ plus cell therapy. The STZ-plus-cell-therapy group was administered human umbilical cord blood-derived CD34⁺ cells weekly for three weeks. At eight weeks, the rats' renal function, pathology, and transcriptome profiles were assessed. Although blood glucose levels did not differ between the STZ-administered groups, urinary albumin excretion was significantly lower at 6 weeks in the STZ-plus-cell-therapy group than in the STZ control group (<i>p</i> < 0.001). Serum creatinine levels tended to be higher in the STZ control group and lower in the STZ-plus-cell-therapy group. Cell therapy significantly improved mesangial expansion, interstitial fibrosis, peritubular capillary rarefaction, and glomerular macrophage infiltration compared with the STZ control (<i>p</i> < 0.0001). Kidney transcriptomics revealed significant upregulation of genes related to M2 macrophage markers, cell homing, and angiogenesis in the STZ-plus-cell-therapy group. In rats with STZ-induced diabetic nephropathy, human CD34⁺ cells ameliorated renal injury through their anti-inflammatory and pro-angiogenic effects.