M2 receptors activation affects proliferation, migration and neurotrophic factors production in rat Schwann-like cells.

Introduction: Schwann cells (SCs) are key regulators of peripheral nerve regeneration and axonal myelination. Although SCs are an attractive therapeutic option for peripheral nerve injuries, there are several restrictions on their clinical application. Adipose derived stem cells (ASCs) represent an attractive source for cell therapies. When exposed to selective growth factors, they can acquire a SC-like phenotype (dASCs) expressing key SCs markers and adopting a spindle-shape morphology. Our group has demonstrated that Acetylcholine, via M2 muscarinic receptors, causes a reversible arrest of cell proliferation in SCs, increasing myelin proteins expression. dASCs also express muscarinic receptors. In the present work we evaluate if M2 muscarinic receptor activation may contribute to dASCs proliferation and phenotype. Methods: Cell growth was analysed by MTS assay. By ELISA and western blot analysis, two different NGF isoforms were detected and their release measured. Cell migration was analysed by wound healing assay. Results: M2 receptor activation causes a reversible arrest of the cell growth, without affecting cell survival. Moreover, they inhibit dASCs migration. M2 receptor stimulation also causes a significant decrease in neurotrophins expression, accompanied by a decreased release of proNGF and mNGF forms. In particular, the apoptotic proNGF isoform (25kDa) is strongly reduced after M2 receptor stimulation. Conclusions: Our data clearly demonstrates that M2 receptor activation inhibits dASCs proliferation and migration, negatively modulating neurotrophins expression and maturation. This indicates that M2 receptors may be relevant for dASCs maturation and myelination, perhaps in a similar way to that observed in SCs.