TGF-beta alters collagen XII and XIV mRNA levels in cultured equine tenocytes.
The effects of TGF-beta 1, beta 2 and beta 3 (TGF-beta) on levels of mRNA corresponding to the alpha chains of type XII and type XIV collagens in equine tenocyte cultures were assessed using the ribonuclease protection assay (RPA). The level of alpha1(XII) mRNA in untreated monolayer cultures was approximately 50- to 100-fold greater than alpha1(XIV) mRNA level. Addition of TGF-beta resulted in an increase in the amount of alpha1(XII) present and a decrease of alpha1(XIV) mRNA in a dose-dependent manner. Specifically, the level of alpha1(XII) mRNA was doubled, but alpha1(XIV) was decreased to 30% of control by the addition of 2 ng/ml of TGF-beta 1 to the cultures. These effects were completely abrogated by neutralizing antibody specific for TGF-beta. In addition, electron microscopy demonstrated that bundled collagen fibers were formed in the intercellular spaces of multilayered tenocytes which had been cultured for 2 weeks in the presence of exogenous TGF-beta 1 together with ascorbic acid phosphate. These results suggest that type XII and/or type XIV collagens modulate the structure of ECM formed by tenocytes in culture.
Arai
Katsuhiko
K
Department of Tissue Physiology, Tokyo University of Agriculture and Technology, 3-5-8 Saiwai-cho, Fuchu, Tokyo 183-7509, Japan. karai@cc.tuat.ac.jp
Kasashima
Yoshinori
Y
Kobayashi
Ataru
A
Kuwano
Atsutoshi
A
Yoshihara
Toyohiko
T
D000818:Animals; D002478:Cells, Cultured; D003094:Collagen / Q000235:genetics*; D024082:Collagen Type XII / Q000235:genetics*; D005109:Extracellular Matrix / Q000378:metabolism / Q000648:ultrastructure; D006023:Glycoproteins / Q000235:genetics*; D006736:Horses; D006801:Humans; D012333:RNA, Messenger / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013710:Tendons / Q000166:cytology; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3
C054447:COL14A1 protein, human; D024082:Collagen Type XII; D006023:Glycoproteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; C508960:TGFB1 protein, human; C509041:TGFB2 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D053781:Transforming Growth Factor beta2; D053782:Transforming Growth Factor beta3; D003094:Collagen