Microarray and miRNA analyses of brain lesions in African- American and Caucasians with multiple sclerosis

Objective: To study if differences in gene expression in brain tissue among African-Americans (AA) and Caucasian Americans (CA) with multiple sclerosis (MS) exist. Understanding any genetic differences is critical for better understanding of MS and its outcomes.Methods: Microarray and microRNA methods were used in chronic brain lesions of AA and CA patients with MS.Results: We found marked downregulation in GM2A (5.2 vs. 2.07), GALC (4.48 vs. 2.66), EIF1AY (4.54 vs. 1.57) and carboxypeptidase D (3.72 vs. 1.79), genes among chronic lesions taken from AA and CA brains and validated using real-time qPCR techniques. A total of 1108 genes were down regulated, compared to 467 genes that were upregulated in chronic MS lesions, compared to normal appearing brain matter (ratio of 2:1); a similar comparison between AA and CA brains revealed a total of 611 down regulated vs. 192 upregulated genes (ratio of 3:1). Interpretation: Significant downregulation of GM2A, GALC, EIF1AY and carboxypeptidase D in the AA lesions as compared to CA cohort could have implications for MS.