Silencing P2Y12 and P2Y13 receptors rehabilitates the ADP-induced P2Y1-mediated osteogenic commitment of post-menopausal mesenchymal stromal cells
摘要
Participation of ADP-sensitive metabotropic P2Y1, P2Y12 and P2Y13 receptors in human osteogenesis is controversial. Here, we investigated the variations in the expression and bone-forming properties of the P2Y1R in osteogenic-differentiating bone marrow-derived mesenchymal stromal cells (BM-MSCs) isolated from post-menopausal (Pm) women. We also tested whether observed P2Y1-related functional deficits result from the crosstalk with co-localized P2Y12 and P2Y13 receptors.
MethodsPm BM-MSCs were cultured in an osteogenic-inducing medium in either the absence or presence of the selective P2Y1 receptor agonist, MR2365; this compound was applied alone or after cells’ incubation with selective P2Y12 and P2Y13 receptor antagonists or short hairpin RNAs designed to silence P2Y12 or P2Y13 receptors gene expression.
ResultsBM-MSCs present immunoreactivity against all ADP-sensitive P2Y receptor subtypes, but their relative density varied among different Pm women and with the time of the cells in the culture. The P2Y1receptor agonist increased the alkaline phosphatase activity and bone nodule formation in BM-MSCs originating from a younger female, but it failed to promote the osteogenic differentiation of BM-MSCs from Pm women unless P2Y12 or P2Y13 receptors are blocked with AR-C66096 and MRS211, respectively. Silencing the P2Y13, but not the P2Y12, receptor gene expression restored the P2Y1-mediated osteogenic commitment of Pm BM-MSCs. The P2Y1 receptor agonist failed to elicit [Ca2+]i transients inside Pm BM-MSCs except after acute cholesterol depletion and lipid rafts disruption with methyl-β-cyclodextrin to prevent the P2Y1/P2Y13 receptors interplay.
ConclusionsThus, personalized offsetting the activity and/or expression of P2Y13 receptor (and P2Y12) may be a good strategy to rehabilitate the P2Y1-mediated osteogenic potential of BM-MSCs and to reduce the fracture risk in Pm women.