Anti-Muscarinic Adjunct Therapy Accelerates Functional Human Oligodendrocyte Repair

Abstract

Therapeutic repair of myelin disorders may be limited by the relatively slow rate of human oligodendrocyte differentiation. To identify appropriate pharmacological targets with which to accelerate differentiation of human oligodendrocyte progenitors (hOPCs) directly, we used CD140a/O4-based FACS of human forebrain and microarray to hOPC-specific receptors. Among these, we identified CHRM3, a M 3 R muscarinic acetylcholine receptor, as being restricted to oligodendrocyte-biased CD140a

How to make an oligodendrocyte

“…To develop more rapid and scalable models for screening large numbers of candidate myelinogenic agents, extensive efforts have thus been undertaken to achieve terminal oligodendrocyte differentiation and myelination in vitro, and to do so using testing platforms that may readily permit adoption across laboratories. These screening systems include high-content imaging of neuronal-OPC co-cultures (Abiraman et al, 2015;Deshmukh et al, 2013), and the imaging-assisted assessment of oligodendroglial interactions with inorganic substrates that permit myelinogenesis and fiber ensheathment (Lee et al, 2012;Mei et al, 2014). Each of these systems is designed to permit the screening of pharmacological agents for their ability to trigger oligodendrocytic maturation and myelin production, as well as for their abilities to modulate astrocyte production from the bipotential OPCs (Fig.…”

“…These include small molecule inhibitors of tankyrase, which is an ADP-polyribosylating enzyme that stabilizes axin and thus releases OPCs from Wnt pathway-mediated differentiation block (Fancy et al, 2011); modulators of receptor tyrosine phosphatase β/ζ (PTPRZ1), which regulates β-catenin signaling and hence the Wnt pathway (McClain et al, 2012;Sim et al, 2006); agonists of retinoid X receptor RXR signaling ; phosphodiesterase inhibition via rolipram (Syed et al, 2013); antagonists of the myelin inhibitory protein LINGO1 Mi et al, 2013); the muscarinic cholinergic antagonists benztropine and solifenacin, which target CHRM1 and CHRM3 and were identified by an unbiased screen and OPC gene expression analysis, respectively (Abiraman et al, 2015;Deshmukh et al, 2013); and the imidazole and sterane representatives miconazole and clobetasol, which were similarly identified by unbiased screening of stem cell-derived OPCs (Najm et al, 2015). These pharmacological approaches towards potentiating myelination from resident progenitors have been extensively reviewed elsewhere (Fancy et al, 2010;Franklin and Goldman, 2015), and will not be further discussed here.…”

Electrophysiological properties of NG2 + cells: Matching physiological studies with gene expression profiles

“…A cluster of antimuscarinic compounds was also identified as promoting NG2 + cell differentiation in a study that assessed the formation of myelin-like wraps around small conical micropillars, and the muscarinic antagonist clemastine was shown to promote oligodendrocyte differentiation and remyelination after demyelination in vivo (Mei et al, 2014). Finally, of particular relevance to humans, M 3 expression was identified in a microarray analysis of FACS-sorted fetal human forebrain OPCs (Abiraman et al, 2015). Treatment of cultured human OPCs with the muscarinic agonist oxotremorine-M prevented their differentiation to oligodendrocytes, while the specific M 3 antagonist darifenacin promoted differentiation.…”

Targeting human oligodendrocyte progenitors for myelin repair

“…One such model is the shiverer mouse, which does not express myelin basic protein, a chief component of the myelin sheath, and has disrupted myelin compaction and neurologic dysfunction. Indeed, when combined with an immunocompromised host such as rag2 , this model is particularly well suited to the study and manipulation of human oligodendrocyte differentiation and myelination (Abiraman et al, 2015). …”