The regeneration of renal microcirculation system with mononuclear-derived cells in chronic renal injury

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14571042
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Kidney internal medicine
• Research Institution: Kansai Medical University
• Principal Investigator: MORI Yasukiyo Kansai Medical University, Faculty of Medicine, Assistant Professor, 医学部, 講師 (40268371)
• Co-Investigator(Kenkyū-buntansha): MATSUBARA Hiroaki Kyoto Prefectural University of Medicine, Faculty of Medicine, Professor, 大学院・医学研究科, 教授 (10239072)
• Project Period (FY): 2002 – 2003
• Keywords: nephritis / chronic injury / cell transplantation / bone marrow / mononuclear cell / regeneration / glomeruli / tubule

Research Abstract

In chronic renal injury, the progression of tubulo-interstitial damages predicts the renal dysfunction. The initial goal of this study was to regenerate the microcirculation system in animal model of chronic renal injury with mononuclear cells implantation and to evaluate the significance in renal function by the implantation. We used intravenous Habu-venome administration followed by the low-dose of Angiotensin II administration subcutaneously with osmotic pump as a chronic rat renal injury model In this model, the deleterious changes such as glomerular sclerosis and tubulo-interstitial fibrosis for 4 to 6 weeks. In addition, blood urea nitrogen and serum creatinine significantly increased (approximately 3-folds increase above the control rats). Initially, the cell transplantation was performed with green fluorescence (PKH2-G1)-labeled mononuclear cells, which were derived from bone marrow. However, we could not clearly determine PKH2-G1-positive cells, because non-specific signals in FITC-wave length in renal tissues, especially in tubules and interstitium were quite high. Therefore, we modified the strategy in transplantation with human mononuclear cells from peripheral blood. After 7 days of cell culture, Lac Z gene was transferred to the cells using microbubble-mediated ultrasonopolation method, which achieved 50% transfection efficiency. The transfected cells were transplanted via renal vein puncture. To trace the transplanted cells, X-gal staining was carried out with frozen tissue of kidney on forth to seventh day after transplantation. β-galactosidase-positive cells were focally detected in some tubules, but not in peritubular regions. In addition, the imuunofluorescence studies with antibodies for β-galactosidase, Aquaporine-1(AQP-1), and von Willebrand (vW) factor showed that some cells in the single layer of tubular epithelium were positive for both β-galactosidase and AQP-1, but not with vW factor. Next, we transplanted these cells into chronic renal injury model with Habu-venome and AngII and followed the effects of transplantation up to 6 weeks. However, we could not observe the significant histological improvements as well as functional changes by transplantation. In conclusion, human mononuclear cells-derived from peripheral blood may, at least in part, differentiate to tubular epithelial cells. To gain histological and functional effects, further improvement in transplantation method will be necessary.