ISSN:
1432-0428
Keywords:
Keywords Islet transplantation
;
porcine xenograft
;
catalase
;
oxidant stress
;
superoxide dismutase
;
reactive oxygen species
;
adenovirus
;
gene transfer.
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Susceptibility of pancreatic islets to oxidant stress may affect islet viability and contribute to primary non function of allo- or xenogenic grafts. We investigated the influence of overexpression of catalase (CAT) on the viability of human, porcine and rat islets, as well as INS-1 beta-cell line. Islets were transfected with a replication-deficient adenovirus vector containing human CAT cDNA under the control of the adenovirus major late promoter (AdCAT) or a vector containing no foreign gene (AdNull) and used as a control. Oxidant stress was induced 48 h later by xanthine oxidase-hypoxanthine (XO 25 mU/ml, HX 0.5 mmol/l) or hydrogen peroxide (100 or 250 μmol/l). Islet cell viability was assessed 72 h after CAT transfer by 4-[3-(4-Idophenyl)-2-(4 nitrophenyl)-2H-5-tetrazolio]-1,2,benzene disulphonate (WST-1) test. Baseline catalase activity was three to fourfold lower in porcine than in human islets. CAT activity was reproducibly increased 2.5- to 7-fold in AdCAT infected islets, at least for 13 days. Overall, AdCAT conferred on human and pig islets a protection of 26.1 ± 6.1 and 21.2 ± 9.8 % on XOHX injury and 35.4 ± 4.2 and 57.9 ± 10.5 % on H2O2 stress. Similarly, rat islet cells and INS-1 cells were protected on XOHX stress by 17.8 ± 2.3 and 30.8 ± 8.7 %, respectively. AdNull had no effect. Basal and stimulated insulin secretion was preserved in AdCAT-transfected human islets despite a XOHX challenge. This study validates adenovirus-mediated catalase gene transfer as a realistic approach to reduce non specific inflammation effects on human or porcine islet grafts. Moreover the relevance of defense mechanisms, previously suggested in human islets, is here illustrated in porcine islets. [Diabetologia (1998) 41: 1093–1100]
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s001250051035
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