Diabetes, Vol 42, Issue 10 1383-1391, Copyright © 1993 by American Diabetes Association
Repair of pancreatic beta-cells. A relevant phenomenon in early IDDM?
DL Eizirik, S Sandler and JP Palmer
Department of Medical Cell Biology, Uppsala University, Sweden.
Most studies dealing with the pathogenesis of IDDM have emphasized the
immune assault against beta-cells. In this perspective, we review the data
that suggest that the beta-cell destruction of IDDM depends on a balance
between beta-cell damage and repair. The progressive beta-cell damage
leading to IDDM seems to follow markedly different temporal courses in
individual patients. Some individuals at high risk for developing IDDM, and
presenting with impaired beta-cell function, appear to recover beta-cell
function when followed prospectively. Moreover, after the clinical onset of
IDDM, most patients experience a transitory period of improved insulin
secretion. In vitro and in vivo experimental data suggest that beta-cells
are indeed able to repair themselves after damage. Dispersed beta-cells or
whole islets can survive and regain their function after a toxic assault.
Furthermore, the abnormal insulin release and glucose oxidation of islets
isolated from NOD mice during the prediabetic period is completely restored
after 1 wk in tissue culture. Finally, treatment of NOD mice with
monoclonal antibodies directed against infiltrating T-cells reverses the
altered glucose metabolism of beta-cells. Note that beta-cell repair after
exposure to different toxic agents can be enhanced both in vivo and in
vitro. Potential enhancers of beta-cell repair are nicotinamide, glucose,
protein-rich diets, and branched chain amino acids. A basic question that
remains to be answered is the nature of the repair mechanisms triggered by
beta-cells.(ABSTRACT TRUNCATED AT 250 WORDS)