Phenotypic Screening-Based Identification of 3,4-Disubstituted Piperidine Derivatives as Macrophage M2 Polarization Modulators: An Opportunity for Treating Multiple Sclerosis

Multiple sclerosis (MS) is a disease of the autoimmune-mediated disorder in the central nervous system, for which no effective therapeutic agent is currently available. The regulation of macrophage polarization toward M2 is a general benefit for treating MS. The gene biomarker-based phenotypic screening approach was developed, and 3,4-disubstituted piperidine derivative S-28 was identified as a lead compound modulating macrophage M2 polarization. Further SAR studies resulted in the discovery of the most potent modulator D11 that showed good oral bioavailability and significant in vivo therapeutic effects. Mechanistic studies demonstrated that the M2 polarization macrophages modulated by D11 mainly functioned through inhibiting the proliferation of T-cells and activating the phosphorylation of Stat3 and Akt. Therefore, the gene biomarker-based phenotypic screening was demonstrated as a promising tool for the discovery of novel macrophage M2 polarization modulators. Compound D11 may serve as a promising starting point for the development of therapeutics to treat MS.