Expression of calbindin-D_28K in motoneuron hybrid cells after retroviral infection with calbindin-D_28K cDNA prevents amyotrophic lateral sclerosis IgG-mediated cytotoxicity

Calbindin-D_28K and/or parvalbumin appear to influence the selective vulnerability of motoneurons in amyotrophic lateral sclerosis (ALS). Their immunoreactivity is undetectable in motoneurons readily damaged in human ALS, and in differentiated motoneuron hybrid cells [ventral spinal cord (VSC 4.1 cells)] that undergo calcium-dependent apoptotic cell death in the presence of ALS immunoglobulins. To provide additional evidence for the role of calcium-binding proteins in motoneuron vulnerability, VSC 4.1 cells were infected with a retrovirus carrying calbindin-D_28K cDNA under the control of the promoter of the phosphoglycerate kinase gene. Differentiated calbindin-D_28K cDNA-infected cells expressed high calbindin-D_28K and demonstrated increased resistance to ALS IgG-mediated toxicity. Treatment with calbindin-D_28K antisense oligodeoxynucleotides, which significantly decreased calbindin-D_28K expression, rendered these cells vulnerable again to ALS IgG toxicity.