Acetylcholine muscarinic M2 receptor maintains human Schwann- like adipose-derived phenotype in the absence of differentiating medium

Human adipose-derived stem cells (ASCs), differentiated in vitro towards Schwann-like phenotype (hdASCs), have been suggested as an alternative source of Schwann cells (SCs). However, although they seem a good alternative, their differentiation is unstable, losing their SC-like phenotype following growth factor withdrawal. Rat and human SCs and dASCs have been characterised for acetylcholine M2 subtype that plays a strategic role in the regulation of
their differentiation. Here we evaluated the M2 muscarinic receptor activation in controlling hdASC proliferation and stabilization of the hdASC phenotype. In accordance with what demonstrated in rat, M2 agonist causes in hdASCs a reversible decrease in cell growth and migration, negatively modulating proliferation markers and upregulating differentiation markers. Remarkably, hdASC differentiation can be stabilised by M2 receptor activation in the absence of differentiation media maintaining a spindle-shaped morphology and SC-like marker expression. These results show that M2 receptor enhances hdASC phenotype, maintaining the expression of key glial markers and supporting their pro-regenerative properties.