Benhamou P Y, Moriscot C, Richard M J, Beatrix O, Badet L, Pattou F, Kerr-Conte J, Chroboczek J, Lemarchand P, Halimi S
Department of Endocrinology, University Hospital, Grenoble, France.
Diabetologia. 1998 Sep;41(9):1093-100. doi: 10.1007/s001250051035.
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 micromol/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.
胰岛对氧化应激的易感性可能影响胰岛活力，并导致同种异体或异种移植物原发性无功能。我们研究了过氧化氢酶（CAT）过表达对人、猪和大鼠胰岛以及INS-1β细胞系活力的影响。用一种复制缺陷型腺病毒载体转染胰岛，该载体在腺病毒主要晚期启动子（AdCAT）控制下含有人类CAT cDNA，或用一种不含外源基因的载体（AdNull）作为对照。48小时后，通过黄嘌呤氧化酶-次黄嘌呤（XO 25 mU/ml，HX 0.5 mmol/l）或过氧化氢（100或250 μmol/l）诱导氧化应激。在CAT转染72小时后，通过4-[3-（4-碘苯基）-2-（4-硝基苯基）-2H-5-四氮唑]-1,2-苯二磺酸盐（WST-1）试验评估胰岛细胞活力。猪胰岛的基础过氧化氢酶活性比人胰岛低三到四倍。在AdCAT感染的胰岛中，CAT活性可重复性地增加2.5至7倍，至少持续13天。总体而言，AdCAT使人类和猪胰岛在XOHX损伤中分别获得26.1±6.1%和21.2±9.8%的保护，在H2O2应激中分别获得35.4±4.2%和57.9±10.5%的保护。同样，大鼠胰岛细胞和INS-1细胞在XOHX应激中分别获得17.8±2.3%和30.8±8.7%的保护。AdNull没有效果。尽管受到XOHX攻击，但AdCAT转染的人胰岛中基础和刺激后的胰岛素分泌得以保留。本研究证实腺病毒介导的过氧化氢酶基因转移是一种切实可行的方法，可减少对人或猪胰岛移植物的非特异性炎症影响。此外，先前在人胰岛中提出的防御机制的相关性，在猪胰岛中也得到了体现。
