Enhancers of human and rodent oligodendrocyte formation predominantly induce cholesterol precursor accumulation

Abstract

Regeneration of myelin in the CNS is being pursued as a potential therapeutic approach for multiple sclerosis. Several labs have reported small molecules that promote oligodendrocyte formation and remyelination in vivo. Recently, we reported that many such molecules function by inhibiting a narrow window of enzymes in the cholesterol biosynthesis pathway. Here we describe a new high-throughput screen of 1,836 bioactive molecules and a thorough re-analysis of more than 60 molecules previously-identified as promoting oligodendrocyte formation from human, rat, or mouse oligodendrocyte progenitor cells (OPCs). These studies highlight that an overwhelming fraction of validated screening hits, including several molecules being evaluated clinically for remyelination, inhibit cholesterol pathway enzymes like EBP. To rationalize these findings, we suggest a model that relies on the high druggability of sterol-metabolizing enzymes and the ability of cationic amphiphiles to mimic the transition state of EBP. These studies further establish cholesterol pathway inhibition as a dominant mechanism among screening hits that enhance human, rat, or mouse oligodendrocyte formation.