Antagonism of the Met5-enkephalin-opioid growth factor receptor-signaling axis promotes MSC to differentiate into osteoblasts
Nikhil A. Thakur, Sean D. DeBoyace, Bryan S. Margulies.
OPRD, OGFR, and the met5-ligand were highly expressed in MSC and osteoblasts. A pulse-dose of naloxone increased mineral formation in MSC cultures in contrast to MSC treated with continuous naloxone or OGFR deficient MSC. Importantly, SMAD1 and SMAD8/9 expression increased after a pulse dose of naloxone whereas SMAD1, SMAD7, and ID1 were increased in the OGFR deficient MSC.