Acetylcholine receptors in mesenchymal stem cells

Mesenchymal stem cells (MSCs) are well known for their regenerative potential. Despite the fact that the ability of MSCs to proliferate and differentiate has been studied extensively, there still remains much to learn about the signalling mechanisms and pathways which control proliferation and influence differentiation phenotype. In recent years, there has been growing evidence for the utility of non-neuronal cholinergic signalling systems and that acetylcholine (ACh) plays an important, ubiquitous, role in cell-to-cell communication. Indeed, cholinergic signalling is hypothesised to occur in stem cells and ACh synthesis, as well as ACh receptor (AChR) expression, has been identified in several stem cell populations; including MSCs. Furthermore, AChRs have been found to influence MSC regenerative potential. In humans, there are two major classes of AChRs, muscarinic AChRs and nicotinic AChRs, with each class possessing several subtypes or subunits. In this review, the expression and function of AChRs in different types of MSC will be summarised with the aim of highlighting how AChRs play a pivotal role in regulating MSC regenerative function