Serum-free Pre-conditioning led to Enhanced BMP-2-Induced Osteochondrogenic Differentiation In Vitro
After 6 days of pre-conditioning followed by 6 days of BMP-2 stimulation in CDM, a difference in response to BMP-2 was observed.
(A) Bright-field images after 6 days of BMP-2 stimulation indicating differentiated cells (black arrows).
(B–E) BMP-2 stimulation induced elevated ALP activity(B). mRNA transcripts displayed elevated expression of SOX9 (C), OSX (D), and ID1 (E) after 24 hr, and 3 and 6 days of BMP-2 stimulation.
(F) IHC for SOX9 (red) and OSX (green) with DAPI (blue) as nuclear stain after 6 days of BMP-2 stimulation.
(G–J) Quantification of merged confocal images expressed as relative units (RU) normalized to DAPI (G). mRNA transcript analysis after pre-conditioning of hPDCs followed by 6 days of stimulation of BMP-2, -6, -7, -9, and GDF5 depicted by SOX9 (H), OSX (I), and ID1 (J). Scale bar, 50 μm; n = 3, ∗/#p < 0.05, ∗∗/##p < 0.01, ∗∗∗/###p < 0.001 where # represents statistical significance to BMP-2 treated condition.