This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Docheva, D. Articles by Brandau, O. Search for Related Content PubMed PubMed Citation Articles by Docheva, D. Articles by Brandau, O.

Tenomodulin Is Necessary for Tenocyte Proliferation and Tendon Maturation

Denitsa Docheva,¹ Ernst B. Hunziker,² Reinhard Fässler,^1* and Oliver Brandau^1,

Department of Molecular Medicine, Max Planck Institute for Biochemistry, Martinsried, Germany,¹ ITI Research Institute, University of Berne, Berne, Switzerland²

Received 15 October 2004/ Accepted 26 October 2004

Tenomodulin (Tnmd) is a member of a new family of type II transmembrane glycoproteins. It is predominantly expressed in tendons, ligaments, and eyes, whereas the only other family member, chondromodulin I (ChM-I), is highly expressed in cartilage and at lower levels in the eye and thymus. The C-terminal extracellular domains of both proteins were shown to modulate endothelial-cell proliferation and tube formation in vitro and in vivo. We analyzed Tnmd function in vivo and provide evidence that Tnmd is processed in vivo and that the proteolytically cleaved C-terminal domain can be found in tendon extracts. Loss of Tnmd expression in gene targeted mice abated tenocyte proliferation and led to a reduced tenocyte density. The deposited amounts of extracellular matrix proteins, including collagen types I, II, III, and VI and decorin, lumican, aggrecan, and matrilin-2, were not affected, but the calibers of collagen fibrils varied significantly and exhibited increased maximal diameters. Tnmd-deficient mice did not have changes in tendon vessel density, and mice lacking both Tnmd and ChM-I had normal retinal vascularization and neovascularization after oxygen-induced retinopathy. These results suggest that Tnmd is a regulator of tenocyte proliferation and is involved in collagen fibril maturation but do not confirm an in vivo involvement of Tnmd in angiogenesis.

Present address: Department of Physiology, LMU-München, 80336 Munich, Germany.

This article has been cited by other articles:

• Tei, K., Matsumoto, T., Mifune, Y., Ishida, K., Sasaki, K., Shoji, T., Kubo, S., Kawamoto, A., Asahara, T., Kurosaka, M., Kuroda, R. (2008). Administrations of Peripheral Blood CD34-Positive Cells Contribute to Medial Collateral Ligament Healing via Vasculogenesis. Stem Cells 26: 819-830 [Abstract] [Full Text]  
• Mendias, C. L., Bakhurin, K. I., Faulkner, J. A. (2008). Tendons of myostatin-deficient mice are small, brittle, and hypocellular. Proc. Natl. Acad. Sci. USA 105: 388-393 [Abstract] [Full Text]  
• Murchison, N. D., Price, B. A., Conner, D. A., Keene, D. R., Olson, E. N., Tabin, C. J., Schweitzer, R. (2007). Regulation of tendon differentiation by scleraxis distinguishes force-transmitting tendons from muscle-anchoring tendons. Development 134: 2697-2708 [Abstract] [Full Text]