钻原卟啉诱导血红素氧化酶-1表达上调对异种移植胰岛的保护作用

Protective effect of cobalt protoporphyrin-induced the strong expression of heme oxygenase-1 on islet xenotransplant

目的研究不同浓度钴原卟啉（CoPP）与其诱导胰岛细胞血红素氧化酶-1（HO-1）表达的效应关系，探讨HO-1表达上调对异种移植胰岛的保护作用。方法将分离和纯化的供者胰岛随机分为5组（A、B、C、D和E组），分别置于含有不同摩尔浓度CoPP的培养液中诱导，5组CoPP的浓度依次为（1、5、25、50和75mmol／L。检测各组胰岛细胞中HO-1mRNA和HO-1蛋白表达情况，并测定体外胰岛素释放水平，筛选出能诱导HO-1表达上调幅度最高的CoPP合适浓度。再将受者分为研究组和对照组（每组8只），对照组移植未经CoPP诱导的供者胰岛细胞；研究组移植经合适浓度CoPP诱导的供者胰岛细胞，术后每天监测受者血糖和排斥反应情况。结果D组HO-1mRNA、蛋白表达上调幅度以及胰岛素分泌量均高于其他4组，差异均有统计学意义（P〈0．05），诱导胰岛细胞HO-1上调幅度最高的CoPP浓度为50mmol／L。研究组受者移植D组供者胰岛后，维持正常血糖的时间为（14．63±1．19）d，对照组为（9．88±2．17）d，两组比较，差异有统计学意义（P〈0．01）。结论在异种胰岛移植中，经50mmol／L的CoPP体外诱导供者胰岛HO-1表达上调幅度最高；HO-1的表达上调可以促进移植胰岛的功能恢复，抑制排斥反应，延长移植胰岛的存活时间。

Objective To analyze the dose-effect relationship between cobalt protoporphyrin （CoPP） and heme oxygenase-1 （HO-1） expression in islets and to investigate the protective effect of strongly expression of HO-1 in islet xenotransplantation- Methods Donor islets isolated and purified from SD rats were randomly divided into 5 groups and incubated with different doses of CoPP for 24 h. Group A： 0 mmol/L; Group B： 5 mmol/L： Group C： 25 retool/L; Group D： 50 mmol/L; Group E： 75 mmol/L. The expression of HO-1 mRNA and protein in islets was detected by RT-PCR and Western blot respectively. Glucose of low and high concentrations was added to islets in vitro to test insulin-releasing function. The optimal dose of CoPP which could induce the strongest HO-1 expression was chosen according to the results. Recipients were randomly divided into 2 groups. Control group received untreated xeno-islets, and the experimental group received islets incubated with optimal CoPP dose in vitro. Glycemia and rejection were observed after transplantation daily. Results The expres- sion of HO-1 mRNA and protein in xeno-islets of group D was significantly higher than in other groups （P〈0. 05）. After stimulation of glucose, the insulin concentration in group D was significantly higher than in other groups （P〈0. 05）. The optimal dose of CoPP which could induce the strongest HO-1 expression was 50 mmol/L. The time for normoglycemia in experimental group was （14. 63 ± 1.19） days, significantly longer than that in control group （9. 88 ± 2. 17）days （P〈0. 01）. Conclusion The strongest expression of HO-1 induced by CoPP in vitro promotes the glucose-stimulated insulin secretion of islets and prolonged the survival of xeno-islet grafts by protecting them from rejection.