Amniotic Fluid Derived Stem Cells with a Renal Progenitor Phenotype Inhibit Interstitial Fibrosis in Renal Ischemia and Reperfusion Injury in Rats.

OBJECTIVES: Mesenchymal stem cells derived from human amniotic fluid (hAFSCs) are a promising source for cellular therapy, especially for renal disorders, as a subpopulation is derived from the fetal urinary tract. The purpose of this study was to evaluate if hAFSCs with a renal progenitor phenotype demonstrate a nephroprotective effect in acute ischemia reperfusion (I/R) model and prevent late stage fibrosis. METHODS: A total of 45 male 12-wk-old Wistar rats were divided into three equal groups;: rats subjected to I/R injury and treated with Chang Medium, rats subjected to I/R injury and treated with hAFSCs and sham-operated animals. In the first part of this study, hAFSCs that highly expressed CD24, CD117, SIX2 and PAX2 were isolated and characterized. In the second part, renal I/R injury was induced in male rats and cellular treatment was performed 6 hours later via arterial injection. Functional and histological analyses were performed 24 hours, 48 hours and 2 months after treatment using serum creatinine, urine protein to creatinine ratio, inflammatory and regeneration markers and histomorphometric analysis of the kidney. Statistical analysis was performed by analysis of variance followed by the Tukey's test for multiple comparisons or by nonparametric Kruskal-Wallis followed by Dunn. Statistical significance level was defined as p <0.05. RESULTS: hAFSCs treatment resulted in significantly reduced serum creatinine level at 24 hours, less tubular necrosis, less hyaline cast formation, higher proliferation index, less inflammatory cell infiltration and less myofibroblasts at 48 h. The treated group had less fibrosis and proteinuria at 2 months after injury. CONCLUSION: hAFSCs contain a renal progenitor cell subpopulation that has a nephroprotective effect when delivered intra-arterially in rats with renal I/R injury, and reduces interstitial fibrosis on long term follow-up.

Proliferation and apoptotic rates and increased frequency of p63-positive cells in the prostate acinar epithelium of alloxan-induced diabetic rats.

The effects of experimental type 1 diabetes were investigated in the acinar epithelium of rat ventral prostate, focusing on the rates of cell proliferation and the frequency of apoptosis and p63-positive cells. Type 1 diabetes was induced in adult male Wistar rats by a single alloxan administration (42 mg/kg b.w.) and its effects were analysed for 1 week and 3 months after the establishment of the disease. A group of diabetic rats was treated daily with 5 IU of insulin during 1 week after diabetes had been diagnosed. Immunocytochemical methods for the localization of cell proliferation antigen (PCNA), androgen receptor (AR) and p63 protein were carried out, and apoptotic cells were identified by TUNEL essay. In diabetic rats, testosterone levels reduced drastically after 1 week and in a lower degree after 3 months. In short-term diabetic rats, cell proliferation decreased, and in medium-term, epithelial apoptotic rates increased. In both periods after the onset of diabetes, the frequency of p63-positive cells doubled. Insulin treatment was effective in preventing testosterone decrease, p63-positive cell increase and apoptotic rates, but did not interfere in cell proliferation. This investigation shows that, soon after diabetes onset, there are important modifications in cell proliferation within the acinar prostatic epithelium, and in longer term, there is a marked impact on kinetics of differentiation and cell death, which may initially be attributable to an androgenic fall, but is probably also because of other factors related to diabetes, as changes are considerably different from those resulting from castration.