title: Transfection of human pancreatic islets with an anti-apoptotic gene (bcl-2) protects beta-cells from cytokine-induced destruction.
abstract: Apoptosis has been identified as a mechanism of pancreatic islet beta-cell death in autoimmune diabetes. Proinflammatory cytokines are candidate mediators of beta-cell death in autoimmune diabetes, and these cytokines can induce beta-cell death by apoptosis. In the present study, we examined whether transfection of human islet beta-cells with an anti-apoptotic gene, bcl-2, can prevent cytokine-induced beta-cell destruction. Human islet beta-cells were transfected by a replication-defective herpes simplex virus (HSV) amplicon vector that expressed the bcl-2 gene (HSVbcl-2) and, as a control, the same HSV vector that expressed a beta-galactosidase reporter gene (HSVlac). Two-color immunohistochemical staining revealed that 95+/-3% of beta-cells transfected with HSVbcl-2 expressed Bcl-2 protein compared with 14+/-3% of beta-cells transfected with HSVlac and 19+/-4% of nontransfected beta-cells. The bcl-2-transfected beta-cells were fully protected from impaired insulin secretion and destruction resulting from incubation for 5 days with the cytokine combination of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and interferon (IFN)-gamma. In addition, the bcl-2-transfected islet cells were significantly protected from cytokine-induced lipid peroxidation and DNA fragmentation. These results demonstrate that cytokine-induced beta-cell dysfunction and death involve mechanisms subject to regulation by an anti-apoptotic protein, Bcl-2. Therefore, bcl-2 gene therapy has the potential to protect human beta-cells in pancreatic islets, or islet grafts, from immune-mediated damage in type 1 diabetes.
authors.affiliation: Department of Medicine, University of Alberta, Edmonton, Canada.
authors.forename: A
authors.initials: A
authors.lastname: Rabinovitch
authors.forename: W
authors.initials: W
authors.lastname: Suarez-Pinzon
authors.forename: K
authors.initials: K
authors.lastname: Strynadka
authors.forename: Q
authors.initials: Q
authors.lastname: Ju
authors.forename: D
authors.initials: D
authors.lastname: Edelstein
authors.forename: M
authors.initials: M
authors.lastname: Brownlee
authors.forename: G S
authors.initials: GS
authors.lastname: Korbutt
authors.forename: R V
authors.initials: RV
authors.lastname: Rajotte
mesh_terms: D017209:Apoptosis / Q000235:genetics*; D002478:Cells, Cultured; D016207:Cytokines / Q000494:pharmacology / Q000502:physiology*; D053938:DNA Fragmentation / Q000187:drug effects; D005822:Genetic Vectors; D006801:Humans; D007150:Immunohistochemistry; D007371:Interferon-gamma / Q000494:pharmacology / Q000502:physiology; D007375:Interleukin-1 / Q000494:pharmacology / Q000502:physiology; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D011994:Recombinant Proteins / Q000494:pharmacology; D018139:Simplexvirus; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology / Q000502:physiology
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D019253:Proto-Oncogene Proteins c-bcl-2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma