Muscarinic acetylcholine receptors present in human osteoblast and bone tissue

Regulation of acetylcholine receptors during differentiation of bone mesenchymal stem cells harvested from human reaming debris

“…Thus, M5 might be down-regulated during osteoporosis in human bone tissue similar to M3 in rat bone. Lui et al analyzed the expression pattern of mAChR in osteoblasts and bone tissue of healthy animals and found a species and bone specific distribution pattern [25]. In human osteosarcoma cells HOS all mAChR subtypes were present [25] whereas in the osteoscarcoma cells SAOS-2 only subtypes M2, M3, and M5 were found [17].…”

“…Lui et al analyzed the expression pattern of mAChR in osteoblasts and bone tissue of healthy animals and found a species and bone specific distribution pattern [25]. In human osteosarcoma cells HOS all mAChR subtypes were present [25] whereas in the osteoscarcoma cells SAOS-2 only subtypes M2, M3, and M5 were found [17]. The more restricted expression pattern of SAOS-2 is in line with (a) native human and rat bone tissue where M1, M4, and M5 were expressed and with (b) cultured mouse bone cells where M2, M3, and M4 were determined [25].…”

“…In human osteosarcoma cells HOS all mAChR subtypes were present [25] whereas in the osteoscarcoma cells SAOS-2 only subtypes M2, M3, and M5 were found [17]. The more restricted expression pattern of SAOS-2 is in line with (a) native human and rat bone tissue where M1, M4, and M5 were expressed and with (b) cultured mouse bone cells where M2, M3, and M4 were determined [25]. However, there is still a controversy since Kauschke et al also detected mAChR M3 in rat bone [13].…”

Altered ultrastructure, density and cathepsin K expression in bone of female muscarinic acetylcholine receptor M3 knockout mice

“…Several cholinergic receptors, transporters, and enzymes were identified in bone forming osteoblasts as well as in bone resorbing osteoclasts [4,5,13]. Acetylcholine and the exogenous ligand nicotine are involved in proliferation of osteoprogenitors and their differentiation into active osteoblasts [13][14][15].…”

“…In doing so the physiological effects depend on the cell type, mAChR subtype and the molecular structure of the receptor [3]. Expression of M3R in osteoblast-like cells was first shown in vitro [4,5] and afterwards in femur of rats and mice and in human ribs [5]. In vertebrae of rats with induced osteoporosis M3R mRNA was downregulated compared to sham operated control rats [6].…”