Bcl-2 and its homologues in the brain of patients with multiple sclerosis.

We measured the mRNA expression levels of molecules involved in scavenging free radicals and in apoptosis within normal appearing white and gray matter (NAWM and NAGM, respectively) and chronic active plaque containing frontal lobe specimens of patients with multiple sclerosis (MS). While no regional differences were detected in the mRNA levels of free radical scavengers, Bcl-XL was higher in plaques than in NAWMs, and both Bak and Bcl-2 were found to be increased in correlation with an immune marker (beta2-microglobulin--beta2Mg) in NAWM and plaque compared with corresponding cortical regions. We did not measure a similar white-gray matter difference in the expression of the latter genes in brains of normal or Alzheimer disease controls. This finding indicates that both pro- and anti-apoptotic mechanisms are activated, not only within but also outside of plaques.