Anti-proliferative and anti-migratory effects are mediated by M2 muscarinic receptor in Schwann-like cells induced from adipose mesenchymal stem cells: implication in nerve regeneration.

Anti-proliferative and anti-migratory effects are mediated by M2 muscarinic receptor in Schwann-like cells induced from adipose mesenchymal stem cells: implication in nerve regeneration. Piovesana R.1,2, Faroni A.2, Magnaghi V.3, Reid A.2, Tata AM1. 1Dept. Biol and Biotech. C. Darwin, University of Rome “Sapienza”, Rome, Italy; 2Blond McIndoe Laboratories, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK; 3Dept.of Pharmacol and Biomol Sciences, University of Milan, Milan, Italy Patients affected by peripheral nerve injury show great functional morbidity, ranging from sensory and motor loss, chronic pain, or a combination of both. The peripheral nervous system has an intrinsic regeneration capability; nevertheless, nerve regeneration outcomes are rarely satisfactory and full functional recovery is often limited. Schwann Cells (SCs) play a central role in the response of the axon injury. The capacity of SCs to proliferate, to secrete growth factors, to modulate immune response, to migrate and to re-myelinate regenerating nerves have been reported. However, SCs show some drawbacks for tissue engineering, such as the difficulty in collection and culture and the slow rate of in vitro expansion. For this reason, the attention of researchers has moved towards other cell types, such as stem cells, presenting best properties for regenerative medicine. The adipose tissue contains mesenchymal stem cells (ASC). ASC can be differentiated in vitro in Schwann-like cells (dASC) following exposure to suitable culture media. SCs express receptors for different neurotrasmitters (i.e. GABA, acetylcholine). In particular, rat SCs express different muscarinic receptor subtypes with higher levels of M2 subtype. M2 receptor activation causes a negative effect on SC proliferation, upregulating transcription factors involved in the promyelinating phase (e.g., Sox10 and Krox20) and downregulating proteins involved in the maintenance of the undifferentiated dASC, like SCs, express functional receptors for different neurotrasmitters, including all muscarinic receptor subtypes. In present work, we characterised the effects mediated by M2 receptors in rat dASC. In dASC, similarly to what observed in SCs, M2 receptor activation caused a reversible reduction of cell proliferation and the inhibition of cell migration without affecting cell survival. After 24h of M2 agonist treatment, we have also observed a significant decrease of neurotrophic factors expression (i.e. NGF, BDNF and GDNF) and an increase of P0 transcript level. Finally the stimulation of M2 receptors enhances a pronounced spindle shaped morphology in dASC with similarities to native SCs. Our data demonstrate that muscarinic receptor activity contributes to modulate dASC proliferation/differentiation. Although further analyses are needed to fully characterise the role of the other muscarinic receptor subtypes, these novel data suggest that cholinergic agonists may support the role of dASC in nerve regeneration by differentially modulating neurotrophic potential.