[Microarray analysis of dedifferentiation related gene expression of human chondrocytes cultured in vitro].
OBJECTIVE
Dedifferentiation of chondrocytes during in vitro expansion is the major cause that limits the potential of chondrocytes for cartilage engineering. This study dissected dedifferentiation mechanism of in vitro cultured human chondrocytes by microarray analysis of gene expression changes.


METHODS
Spare human costal cartilage from ear reconstruction patients (n=3, aged 10-20) were digested with collagenase II to isolate human chondrocytes(HCC) and were expanded from P1 to P4. For microarray, RNA was isolated from the P1 and P4 cells and labeled with cy3 and cy5 fluorescence respectively as probes to hybridize a cDNA microarray( about 8300 genes). Those genes with 2-fold difference of expression were selected.


RESULTS
Microarray results showed that 56 genes were up-regulated at P4, including proteases, inflammatory factors, growth suppressor and apoptosis genes. Down-regulated 84 genes at P4 include extracellular matrices, protein anabolism, growth factors, cell cycle and cytoskeleton related genes.


CONCLUSIONS
These results provide insight into the mechanism of chondrocytes dedifferentiation. The characteristic appearance of dedifferentiation related genes expression includes increased level of stress response and inflammation. The down-regulation of anabolic metabolism related genes and up-regulation of proteases genes leaded to extra cellular matrix decrease. Decreased production of growth factors and increased apoptosis cause decreased cell proliferation of dedifferentiation chondrocytes.
Zhang
Yan
Y
Department of Plastic Surgery, Ninth People's Hospital, Shanghai Key Laboratory of Tissue Engineering, Shanghai Tissue Engineering Center, 200011, China.
Chai
Gang
G
Liu
Wei
W
Zhou
Guang-dong
GD
Cui
Lei
L
Cao
Yi-lin
YL
D000293:Adolescent; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000235:genetics*; D002478:Cells, Cultured; D002648:Child; D019902:Chondrocytes / Q000166:cytology*; D015536:Down-Regulation; D005109:Extracellular Matrix / Q000378:metabolism*; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000235:genetics; D023822:Tissue Engineering / Q000379:methods; D015854:Up-Regulation; D055815:Young Adult
D012313:RNA