Figure 6. NPY inhibited osteogenesis and elevated RANKL/OPG ratio through Y1R via suppression of cAMP/PKA/CREB pathway in BMSCs. (A, C) Western blotting results of OPG, RANKL, RUNX2, OCN, p-PKAs and p-CREB expression in BMSCs after day 7 and 21 of incubation in osteogenic medium with NPY, NPY+BIBO3304 or NPY+cAMP. (B) ALP staining on day 7, and Alizarin red S staining of BMSCs on day 21 of incubation in osteogenic medium with NPY, NPY+BIBO3304 or NPY+cAMP. The data are expressed as the means ± SD. *P<0.05; **P<0.01; ***P<0.001; ****P<0.0001 vs. CON, and #P<0.05; ##P<0.01; ###P<0.001; ####P<0.0001 vs. NPY by one-way ANOVA and Tukey’s post hoc test.