Fig. 1

MSC, but not AC, undergo hypertrophy under chondrogenic conditions. MSC (N = 6 donors) or AC (N = 4 donors) were subjected to chondrogenic conditions and evaluated at the end of their chondrogenesis. a Representative images for Safranin O staining, and collagen type II or type X immunohistochemistry. Scale bar, 100 μm. b mRNA expression for indicated genes was measured by qRT-PCR, and values were normalized to three housekeeping genes (ACTB, HPRT, RLP13). c Alkaline phosphatase activity (ALP) measured in culture media from cell pellets. Mean values ±  SD are shown (MSC—gray, AC—white); *p ≤ 0.05, **p ≤ 0.01 (Mann-Whitney U)