ABSTRACT
BACKGROUND/AIMS: DNA fragmentation is one of the typical features of apoptosis, frequently induced by oxidative stress. Increased oxidative stress is known to be related to several pathological processes. In this study, we assessed oxidative damage in the early follow-up period after kidney transplantation measuring DNA oxidation and fragmentation of mononuclear cells and the circulating levels of inflammatory cytokines. METHODS: Blood samples from 30 kidney transplant recipients were collected before transplantation and after 2 days, 1 month and 6 months. Oxidative DNA fragmentation was measured by Comet Assay, whereas DNA oxidation was evaluated measuring 8-OHdG leukocyte levels. Serum IL-1ß, IL-4, IL-6, IL-8, IL-10, IFN-γ and TNF-α were assayed using a multiplex ELISA analysis. RESULTS: At 6 months after transplantation, a significant reduction in DNA fragmentation and IL-6 plasma levels was observed; DNA oxidation was higher in patients with a worse outcome, with delayed graft function and low nutritional status. We also found a correlation of IL-6 and IL-10 levels with DNA fragmentation and of IL-10 levels with DNA oxidation. CONCLUSION: Low levels of oxidation and apoptosis at 6 months after transplantation correlate with a better recovery of renal function in kidney allografts. The measurement of cytokine levels confirmed a reduction of inflammatory parameters within 6 months of follow-up.
Subject(s)
Kidney Transplantation/methods , Oxidative Stress , 8-Hydroxy-2'-Deoxyguanosine , Aged , Comet Assay , DNA/chemistry , DNA Fragmentation , Deoxyguanosine/analogs & derivatives , Deoxyguanosine/pharmacology , Enzyme-Linked Immunosorbent Assay/methods , Female , Graft Survival , Humans , Inflammation , Interleukin-10/chemistry , Male , Middle Aged , Oxygen/chemistry , Time Factors , Treatment OutcomeABSTRACT
BACKGROUND/AIMS: Vitamin D deficiency is associated with endothelial dysfunction in uremic patients, possibly by the impairment in the number and function of endothelial progenitor cells (EPCs). In 89 hemodialysis patients, we investigated the factors associated with the number of circulating EPCs (CD34+/CD133+/KDR+ and CD34+/CD133-/KDR+ cells), the presence of VDR and the determinants of VDR expression on EPCs, in particular in calcitriol therapy. METHODS: EPC counts, percentages of VDR-positive EPCs and VDR expression were assessed by flow cytometry. Cells isolated from a subgroup of patients were cultured to analyze colony-forming units, specific markers expression and a capillary-like structure formation. RESULTS/CONCLUSIONS: Our study demonstrates the presence of VDR on EPCs. In our dialysis patients, the parameters studied on both CD34+/CD133+/KDR+ and CD34+/CD133-/KDR+ cells, in particular VDR expression, seem to be influenced by uremia-related factors, including anemia, inflammation, diabetes, 25(OH)D serum levels and calcitriol therapy.
Subject(s)
Calcifediol/blood , Calcitriol/administration & dosage , Endothelial Cells/metabolism , Gene Expression Regulation/drug effects , Receptors, Calcitriol/biosynthesis , Stem Cells/metabolism , Vitamins/administration & dosage , Adult , Aged , Antigens, Differentiation/biosynthesis , Endothelial Cells/pathology , Female , Humans , Male , Middle Aged , Stem Cells/pathology , Uremia/blood , Uremia/complications , Uremia/pathology , Uremia/therapy , Vitamin D Deficiency/blood , Vitamin D Deficiency/drug therapy , Vitamin D Deficiency/etiology , Vitamin D Deficiency/pathologyABSTRACT
There is increasing proof that organ preservation by machine perfusion is able to limit ischemia/reperfusion injury in kidney transplantation. This study was designed to compare the efficiency in hypothermic organ preservation by machine perfusion or cold storage in an animal model of kidney autotransplantation. Twelve pigs underwent left nephrectomy after warm ischemic time; the organs were preserved in machine perfusion (n = 6) or cold storage (n = 6) and then autotransplanted with immediate contralateral nephrectomy. The following parameters were compared between the two groups of animals: hematological and urine indexes of renal function, blood/gas analysis values, histological features, tissue adenosine-5'-triphosphate (ATP) content, perforin gene expression in kidney biopsies, and organ weight changes were compared before and after preservation. The amount of cellular ATP was significantly higher in organs preserved by machine perfusion; moreover, the study of apoptosis induction revealed an enhanced perforin expression in the kidneys, which underwent simple hypothermic preservation compared to the machine-preserved ones. Organ weight was significantly decreased after cold storage, but it remained quite stable for machine-perfused kidneys. The present model seems to suggest that organ preservation by hypothermic machine perfusion is able to better control cellular impairment in comparison with cold storage.
