Gene Therapy for Diabetes mellitus

Overview

Multiple genetic factors are involved in the pathogenesis of type 1 and type 2 diabetes mellitus. A defect, whichcould be ascribed to a single or only few genes, has not been established yet. An exception represents the MaturityOnset Diabetes of the Young (MODY) which is rather rare and is caused by mutations in some of 6 known genes.Principles of gene therapy focus mainly on generation of replenishable sources of insulin producing tissue, whichcould be used for replacement of the destroyed or failing β-cells. Current approaches include stimulation of embryonicor adult stem cell proliferation and differentiation into β-cells, β-cell proliferation, transdifferentiation of non-isletcells into glucose-sensitive insulin-producing cells and xenotransplantation. Genetic modification is being studiedto prevent islet rejection (e.g. local expression of immuno-suppressive cytokines or ligands inducing T-cell apoptosis,knock-out of specific animal genes or transfer of human genes into animal tissue donors) or to construct „superislets“resistant to apoptosis or oxidative stress. For prevention of type 1 diabetes and perhaps for induction of specificimmune tolerance vaccination with DNA fragments encoding for specific auto or alloantigens represents a promisingapproach. In addition, gene therapy offers some hope for the future treatment of diabetic vascular complication,neuropathy and syndromes of insulin resistance.

Key words:
gene therapy, diabetes mellitus, transplantation, pancreatic islets, stem cells.