Effects of serum from patients with type 1 diabetes on primary cerebellar granule cells

Type 1 diabetes is an autoimmune disease of unknown etiology. Our previous work has shown that a factor present in serum from type 1 diabetic patients causes increased Ca²⁺ channel activity and apoptotic DNA fragmentation in pancreatic β-cells. Here we examined the effects of type 1 diabetic serum on primary cerebellar granule cells (CGCs). In CGCs, exposure to type 1 diabetic serum did not cause increased apoptosis or changes in Ca²⁺ channel activity. However, patient serum did cause modulation of Ca²⁺ signals in a cell type with triangular soma that exhibited low voltage-gated Ca²⁺ currents. This cell was present primarily in cultures exposed to type 1 diabetic serum. The presence of low voltage-gated Ca²⁺ currents and long neuronal dendrites indicated that this unique cell was of neuronal origin and not of glial origin.