血红素加氧酶-1诱导性高表达保护异种移植胰岛功能的研究

目的 探讨通过钴原卟啉(cobalt protoporphyrin,CoPP)诱导供体胰岛血红素氧化酶-1(heme oxygenase-1,HO-1)高表达对异种胰岛移植物的保护作用.方法 采用大鼠对小鼠胰岛移植模型,分为对照组、体内诱导组、体外诱导组、体内阻断组及体外阻断组5组,改良Gotoh法提取胰岛,移植于糖尿病模型小鼠的肾包膜下.比较各组受体移植后血糖维持正常时间,糖刺激试验检测胰岛功能,PCR和ELISA法分别检测移植物内和血清IL-10、TNF-α、IL-1β及INF-γ及其mRNA表达.分别以PCR和Western印迹法检测胰岛组织内HO-1mRNA及蛋白表达.病理学检查移植物淋巴细胞浸润情况.结果 对照组小鼠血糖维持正常时间为(9.33±1.37)d,与体内诱导组的(16.33±1.51)d及体外诱导组的(14.33±1.51)d相比差异有统计学意义(P<0.05),体内诱导组优于体外诱导组(P<0.05).受体阻断的两组血糖控制时间则与对照组相近,分别为:体内阻断组(9.67±1.03)d,体外阻断组(9.17±1.47)d.体内、外诱导组及对照组胰岛于低糖刺激下胰岛素分泌量差异无统计学意义(P>0.05),而高糖刺激下,体内诱导、体外诱导及对照组分别为:(187.68±19.93)、(137.22±11.73)及(91.25±12.64)μIU·ml~(-1)·10islets~(-1)·45 min~(-1),差异有统计学意义(P<0.05).移植后,接受经诱导处理的胰岛的两组小鼠血清IL-10含量[体内诱导(72.97±9.74)pg/ml、体外诱导(70.84±3.56)pg/ml]明显高于未处理组[(30.57±3.93)pg/ml]及阻断两组[体内阻断:(39.78±3.00)pg/ml、体外阻断:(35.42±4.30)pg/ml].两诱导组胰岛移植物的IL-10 mRNA表达强于对照及阻断两组.IFN-γ、TNF-α及IL-1β在各组间差异无统计学意义.体内、体外诱导两组HO-1mRNA、蛋白表达高于对照组,其中体内诱导组HO-1mRNA高于体外组,但两组HO-1蛋白表达相当.体内、外阻断组HO-1mRNA、蛋白表达与对照组相当.病理学检查示两诱导组移植物内淋巴细胞浸润少于对照及阻断两组. 结论 CoPP体内、外诱导He-1高表达可促进胰岛功能,延长移植物生存时间,体内诱导对异种移植胰岛保护效应强于体外诱导.

The protection of xenotransplanted murine pancreatic islets by induced expression of heme oxygenase-1

Objectlve To explore the mechanism of the protection in high expression of HO-1 induced by CoPP on murine islet xenografts. Method An islet transplantation of a SD rat-to-C57 BL/6 mouse model was established.Mice were randomized into five groups i.e.control,CoPP-induction in vivo,CoPP+ZnPP in vivo.CoPP-induction in vitro and CoPP+ZnPP in vitro and the islet xenografts were transplanted into the subrenal capsule.Normoglycemia time was recorded and insulin-releasing test was performed.IL-10、TNF-α、IL-1β and INF-γ in serum and their cytokine mRNA and HO-1 in xenografts were measured by RT-PCR and Western-blotting.The pathological examination was done to observe the lymphocyte infiltration. Results There Was significant difference in the normoglycemia time between CoPP-induction in vivo and in vitro and other three groups.The results of insulin-releasing stimulated by low level glucose were identical among groups,but that of insulin-releasing stimulated by high-glucose in in vivo group were the hiishest as in CoPP-induction in vivo and in vitro and control group were 187.68 ±19.93、137.22±11.73,91.25±12.64 μIU·ml~(-1)·10islets~(-1)·45 min~(-1),(P<0.05).The IL-10 in serum in CoPP-induction in vivo and in vitro(in vivo:72.97±9.74 pg/ml;in vitro:70.84±3.56 pg/ml)was significantly hisher than other three groups(control:30.57±3.93 pg/ml;CoPP+ZnPP in vivo:39.78±3.00 pg/ml;CoPP+ZnPP in vitro:35.42±4.30 pg/ml).The expression tendency of IL-10 mRNA was similar to that of insulin secretion.There was no significant difieFence in TNF-α、IL-1β and INF-γ.The expression of HO-1 by PCR and Western-blot analysis in CoPP-induction in vivo and vitro was higher than other three groups.The pathological examination showed that fewer lymphocytes infiltrated into the islet xenografts from CoPP-treated in comparison with xenografts from other three groups. Conclusion HO-1 could improve the survival of islet xenograft:the induetion of HO-1 expression in vivo was much mole efficient than in vitro.The CoPP-induction could be related to immune modulation of IL-10.