体内外诱导血红素加氧酶-1延长异种移植胰岛功能和生存

Background  The induced expression of heme oxygenase-1 (HO-1) in donor islets improves allograft survival. Cobalt protoporphyrin (CoPP) could significantly enhance the expression of HO-1 mRNA and protein in rat islet safely. Our work was to study how to protect pancreatic islet xenograft by CoPP-induction.

Methods  Islet xenografts treated with CoPP-induction and CoPP+ Zinc protoporphyrin (ZnPP) in vitro and in vivo were randomly transplanted into murine subrenal capsule; then the graft survival time was compared by blood glucose level and pathological examination and meanwhile the interferon γ (IFN-γ), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10) and IL-1β level in serum and their mRNA and HO-1 mRNA and protein expression were examined.

Results  Islets with CoPP-induction under low- and high-glucose stimulation exhibited much higher insulin secretion compared with other three groups. CoPP-induction could increase higher expression of HO-1 (mRNA: 3.33- and 76.09- fold in vitro and in vivo; protein: 2.85- and 58.72-fold). The normoglycemia time in induction groups ((14.63±1.19) and (16.88±1.64) days) was significantly longer. The pathological examination showed less lymphocyte infiltration in induction groups. The IL-10 level and its mRNA in induction groups were significantly higher.

Conclusions  The HO-1 induced by CoPP would significantly improve function, prolong normoglycemia time and reduce lymphocyte infiltration. Meanwhile CoPP-induction in vivo had more beneficial effects than in vitro. Its mechanism could be related to immune-modulation of IL-10.

Hemo Oxygenase-1 Induction In Vitro and In Vivo Can Yield Pancreas Islet Xenograft Survival and Improve Islet Function

Background The induced expression of heme oxygenase-1 (HO-1) in donor islets improves allograft survival.Cobalt protoporphyrin (CoPP) could significantly enhance the expression of HO-1 mRNA and protein in rat islet safely.Our work was to study how to protect pancreatic islet xenograft by CoPP-induction.Methods Islet xenografts treated with CoPP-induction and CoPP+ Zinc protoporphyrin (ZnPP) in vitro and in vivo were randomly transplanted into murine subrenal capsule; then the graft survival time was compared by blood glucose level and pathological examination and meanwhile the interferon γ (IFN-γ),tumor necrosis factor a (TNF-α),interleukin 10 (IL-10) and IL-1β level in serum and their mRNA and HO-1 mRNA and protein expression were examined.Results Islets with CoPP-induction under low- and high-glucose stimulation exhibited much higher insulin secretion compared with other three groups.CoPP-induction could increase higher expression of HO-1 (mRNA:3.33- and 76.09-fold in vitro and in vivo; protein:2.85- and 58.72-fold).The normoglycemia time in induction groups ((14.63±1.19) and (16.88+1.64) days) was significantly longer.The pathological examination showed less lymphocyte infiltration in induction groups.The IL-10 level and its mRNA in induction groups were significantly higher.Conclusions The HO-1 induced by CoPP would significantly improve function,prolong normoglycemia time and reduce lymphocyte infiltration.Meanwhile CoPP-induction in vivo had more beneficial effects than in vitro.Its mechanism could be related to immune-modulation of IL-10.