Researchers in Israel have reported a novel approach to treating diabetes. They have used gene therapy to make liver cells turn into insulin-producing pancreatic-like cells. In mice experiments, the new liver cells produced insulin which was biologically active.
The researchers describe their work in the current issue of Nature Medicine (2000;6:568). It involved a "gain of function" approach to test whether the gene PDX-1, which encodes a protein that is central in regulating pancreatic development and islet cell function, could endow a non-islet tissue with pancreatic beta cell characteristics in vivo. Adenoviruses were used to transfer the PDX-1 gene to the livers of mice that had been made hyperglycaemic. The hepatic cells then produced insulin which was able to ameliorate the hyperglycaemia.
The researchers comment that the techniques of pancreas transplantation or islet cell implantation efficiently restore normoglycaemia but require life-long immunosuppression and are limited by tissue supply. "Our study presents a new approach for extending the beta-cell phenotype to additional ‘self' tissues, which may compensate for the inadequate beta-cell function and thereby circumvent the need for transplantation and immunosuppression," they say.
In an accompanying commentary, Dr Axel Kahn (INSERM, France) says: "Although considerable efforts will be needed to fully characterise the events triggered in the liver by expression of PDX-1, these results could constitute a breakthrough in the prospects of therapy for type 1 diabetes."