TY - JOUR TI - Sequential synthesis of cartilage and bone marker proteins during transdifferentiation of mouse Meckel's cartilage chondrocytes in vitro. AU - Ishizeki, K AU - Hiraki, Y AU - Kubo, M AU - Nawa, T T2 - The International Journal of Developmental Biology AB - Meckel's cartilage cells cultured in vitro undergo phenotypic transformation toward osteogenic cells. We examined whether these cells synthesize type X collagen and bone morphogenetic protein-2 (BMP-2). We also examined the results of Alcian blue staining and the expression of type I and type II collagen, osteocalcin and chondroitin sulfate proteoglycan (CSPG) during this transdifferentiation. Meckel's chondrocytes, isolated from day-17 mouse embryos, were inoculated at 1 x 10(4)/penicylinder and cultured in alpha-MEM for periods up to 4 weeks. Alcian blue staining and immunostaining of type II collagen and CSPG confirmed that, after cell culture for 2 weeks, the cartilaginous phenotype was expressed most intensely. Later in culture, chondrocytes underwent modification through the synthesis of bone-type proteins; nodule-forming small round cells showed ALPase activity and were immunoreactive for type I collagen and osteocalcin. Immunoreactivity for type X collagen was detected in the small round cells at the top of the nodules prior to calcification of the matrix, as well as in large hypertrophic cells. BMP-2 was also expressed first in similar small round cells after 3 weeks in culture, and it subsequently extended along the extracellular matrix in the calcified nodules. These results indicate that small round cells that are differentiating toward osteocyte-like cells from Meckel's chondrocytes express type X collagen and BMP-2 sequentially. PY - 1997 VL - 41 IS - 1 SP - 83 EP - 89 J2 - Int. J. Dev. Biol. LA - en SN - 0214-6282 SN - 1696-3547 UR - https://ijdb.ehu.eus/article/9074940 Y2 - 2024/05/06/23:27:28 ER -