Expression and modulation of ghrelin O-acyltransferase in cultured chondrocytes.
OBJECTIVE
To use reverse transcription-polymerase chain reaction to detect ghrelin O-acyltransferase (GOAT) transcripts in both murine and human chondrocytes, to evaluate the effect of pharmacologic in vitro treatments with lipopolysaccharide (LPS), growth hormone, ghrelin, and dexamethasone on GOAT messenger RNA (mRNA) expression, and to study the GOAT mRNA profile during chondrocyte differentiation.


METHODS
Murine and human GOAT and ghrelin mRNA levels were determined by the SYBR Green-based quantitative real-time polymerase chain reaction method.


RESULTS
GOAT mRNA was expressed in murine cartilage explants as well as in the cultured murine chondrogenic ATDC-5 cell line. GOAT was also expressed in human immortalized chondrocyte cell lines and in human cultured primary chondrocytes. In addition, GOAT mRNA expression in differentiating ATDC-5 cells was lower at the early stage of differentiation (days 3-7), whereas GOAT mRNA levels increased progressively at the late stages. Finally, among the drugs and hormones tested, only LPS was able to strongly decrease GOAT mRNA expression.


CONCLUSIONS
These data indicate that chondrocytes are equipped with biochemical machinery for the synthesis of acylated ghrelin and suggest a novel role of the ghrelin axis in prehypertrophic and hypertrophic chondrocyte differentiation during endochondral ossification.
Gómez
Rodolfo
R
Santiago University Clinical Hospital, Santiago University School of Medicine, Santiago de Compostela, Spain.
Lago
Francisca
F
Gómez-Reino
Juan J
JJ
Dieguez
Carlos
C
Gualillo
Oreste
O
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D019902:Chondrocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D054439:Ghrelin / Q000378:metabolism / Q000494:pharmacology; D013006:Growth Hormone / Q000494:pharmacology; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology; D008565:Membrane Proteins; D051379:Mice; D023421:Models, Animal; D012333:RNA, Messenger / Q000378:metabolism
D054439:Ghrelin; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D012333:RNA, Messenger; D003907:Dexamethasone; D013006:Growth Hormone; D000217:Acyltransferases; C542776:MBOAT4 protein, human; C526983:Mboat4 protein, mouse