Drug repositioning and computational analysis for myelin disease regenerative therapies

CNS demyelination is usually the consequence of a direct insult to oligodendrocytes (OL), the cells that make and maintain the myelin sheath, and remyelination is critical to restore electrical impulse conduction and protect axons from degeneration. Current therapies for multiple sclerosis (MS) do not attain control of progression, tissue damage is not healed and disability accumulates. The main focus of regenerative therapies for MS is to induce the differentiation of oligodendrocyte progenitor cells (OPC) present within areas of demyelination into remyelinating OL. Recent studies have been focused on identifying targets and molecules that promote remyelination, but to date, no therapeutics are available to improve this regenerative process. Our search for new therapies is based on the results of an extensive repurposing screening for remyelination potential of 2.000 registered drugs and natural compounds that we have recently performed. We are now characterizing and validating the biological activity and chemical structure of the 3 putative pro-remyelinating hit compounds identified in the primary screening by applying well established procedures of the modern drug discovery pipeline. The results of the hit validation phase, that will be presented at the meeeting, include: i) analytical characterization of purity of selected compounds by Proton Nuclear Magnetic Resonance Spectroscopy (1HNMR) and Liquid chromatography–mass spectrometry (LC/ MS) techniques; ii) compound re-testing performed on indepen- dently purchased stocks of substances, with adequate standards of purity, evaluating their remyelinating potential in the damaged CNS tissue; iii) dose-response analysis with 5 concentrations tested per compound in OPC cultures and EC50 value generation; iv) selec- tion of at least 5 chemical drug-like analogs for each of the hit com- pound by means of chemoinformatic techniques, and experimental testing to assess their activity on the differentiation of OPC and on remyelination of axons; v) intellectual property evaluation, check- ing the hit compound structures in specialized databases to define their patentability. This combined computational and experimental approach rep- resents the first step of the hit to lead process in search for the optimal myelin-promoting compound(s).