MODEL B CELLS FOR USE IN DIABETES TREATMENT

Emory University, Atlanta GA

Investigators

Linked publications & trials

Abstract

Transplantation of islets or Beta-cells offers a realistic possibility for physiological control of blood glucose in diabetics. All reports agree that euglycemia can be achieved for a limited time period (less than 1 year) following transplantation. A major limitation to using normal islets or Beta-cells in implantable bioartificial pancreata is availability. Normal cells isolated from mammalian glands exhibit littl growth, and rapidly lose their differentiated properties in culture. With an estimated 300,000 cases of insulin dependent diabetes mellitus and an additional 30,000 new cases per year in the USA, alone, the deman for islets would be enormous. Consequently, cell lines which retain in culture the differentiated properties of normal islets in vivo are neede for the development of a bioartificial pancreas. Since all living systems need energy to sustain their life and function, knowledge about their energy metabolism as it responds to expected physiologic changes is crucial in assessing the viability and function of these bioartificia devices. In this application, we propose to study the bioenergetic stability of the continuous Beta cell line, BetaTC3, in an immunoprotected environment under repetitive glucose stimulations and hypoxic stresses. Furthermore, we will implant immunoprotected BetaTC3 cells in streptozotocin-induced diabetic rats, and investigate their ability to restore glucose regulation in these animals. This type of information is currently unavailable, and will add greatly to the understanding of the capabilities and limitations of an implantable bioartificial pancreas. We propose to use the non-invasive modality of Nuclear Magnetic Resonance spectroscopy, for both in vitro and in vivo studies. 31P NMR will assess intracellular levels of high and low energ phosphates, and 13C NMR will determine the relative fluxes through glycolysis and the tricarboxylic acid cycle. Enzymatic assays of the perfusion medium effluent, perchloric acid extract of the cells, and histologic examinations of the beads will be performed in support of the in vitro studies. Changes in tissue biochemistry and key physiological parameters including blood glucose and insulin levels will be monitored to assess the success of the implant. This proposal is the beginning of an interdisciplinary project that has brought together expertise from engineering, chemistry, physics and medicine. Our long range goal is to develop a clinically useful implantable bioartificial pancreas for the treatment of diabetes mellitu in human patients.