诱导供者胰岛细胞高表达血红素加氧酶-1延长大鼠胰岛移植物的存活时间

目的 探讨钴原卟啉(CoPP)诱导大鼠胰岛细胞高表达血红素加氧酚1(HO-1)后,对延长胰岛移植物存活时间的作用.方法 (1)将分离和纯化的供者(BN大鼠)胰岛细胞分为CoPP诱导组和未诱导组.CoPP诱导组供者在分离胰岛细胞前3天和前1天腹腔注射2.5 mg/kg的CoPP,未诱导组不注射CoPP.诱导后,采用免疫荧光法及Western免疫印迹法检测两组胰岛细胞中HO-1的表达情况,采用酶联免疫吸附试验(ELISA)和葡萄糖刺激试验检测胰岛细胞的胰岛素释放水平.(2)Lewis大鼠经四氧嘧啶静脉注射后建立糖尿病模型,取10只成功建立糖尿病模型的大鼠作为胰岛细胞移植的受者,随机平均将受者分为实验组和对照组,分别移植经CoPP诱导和未经诱导的供者胰岛细胞.移植后,观察和比较两组受者胰岛移植物的存活时间和发生排斥反应后胰岛移植物的组织病理学变化.结果 CoPP诱导组胰岛细胞高表达HO-1,而未诱导组不表达HO-1;CoPP诱导组和未诱导组供者胰岛细胞胰岛素分泌量,在低糖刺激下分别为(15.65±0.89)mU/L和(12.28±0.89)mU/L(P>0.05),在高糖刺激下分别为(46.60±1.13)mU/L和(19.01±1.49)mU/L(P<0.05),刺激指数分别为2.98±0.10和1.55±0.01(P<0.05).实验组和对照组胰岛移植物平均存活时间分别为(12.20±5.67)d和(5.60±1.14)d(P<0.05);当受者发牛排斥反应时,对照组胰岛移植物周边可见明显的淋巴细胞、成纤维细胞以及单个核细胞浸润,而实验组细胞浸润的程度明显较轻.结论 CoPP可诱导大鼠胰岛细胞高表达HO-1,其对胰岛细胞有明显保护作用.移植高表达HO-1的胰岛细胞能显著延长胰岛移植物的存活时间.

HO-1 overexpression induced by CoPP in donors can prolong the survival of transplanted allogeneic islets of rats

Objective To investigate the effects of the overexpression of HO-1 induced by CoPP in the donor on the survival of transplanted allogeneic islets of rats and the mechanism.Methods (1) Brown Norway rats were randomly divided into control group, and CoPP-induced group receiving intraperitoneal injection of CoPP (2.5 mg/kg) at 3rd and 1st day prior to islet isolation.By using the cytoimmunofluorescenee and Western blot, the expression of HO-1 in isolated islets was detected.The insulin level in the supernatant of the cultured islets stimulated with glucose was determined by ELISA.(2) Lewis male rat diabetic models were established by a single intravenous injection of alloxan, and then randomly divided into CoPP group and control group.Islets were transplanted under the left kidney capsule of each diabetic recipient.The survival time after transplantation, and pathological changes following rejection of the islet grafts were analyzed.Results The HO-1 was highly expressed in the islets isolated from CoPP-treated rats by cytoimmunofluorescence and Western blot.After stimulation with 16.7 mmol/L glucose, the insulin concentration in Copp-treated and Copp-untreated groups was (46.60± 1.13) and (19.01 ± 1.49) mIU/L respectively (P<0.05).The insulin concentration in Copp-treated and Copp-untreated groups in islets stimulated with 5.6 mmol/L glucose was (15.65 ± 0.89) and (12.28 ± 0.89) mU/L respectively (P>0.05).The stimulated index in Copp-treated and Copp-untreated groups was (2.98 ± 0.10) and 1.55 + 0.01 respectively (P< 0.05).The survival time of islets allograft in Copp-treated and Copp-untreated groups was separately (12.20±5.67) and (5.60± 1.14) days respectively (P<0.05).Histological analysis revealed the presence of more islands of insulin-positive cells and considerably fewer lymphocytes or inflammatory infiltration than the controls.Conclusions CoPP could induce the HO-1 expression of islets, and improve their function.Over-expression of HO-1 in islets could prolong survival time of islets allograft.