Anti-angiogenic action of the C-terminal domain of tenomodulin that shares homology with chondromodulin-I

Abstract

Tenomodulin (TeM) is a type II transmembrane glycoprotein that contains a C-terminal domain with homology to the mature, secreted form of chondromodulin-I (ChM-I), a cartilage-derived angiogenesis inhibitor. TeM transcripts have been found in hypovascular tissues such as tendons and ligaments but the biological activity of TeM has not yet been fully explored. Using an adenovirus expression system, we utilized the forced expression and subsequent secretion of the human TeM C-terminal 116 amino acids (Ad-shTeM) in human umbilical vein endothelial cells (HUVECs) to assess the anti-angiogenic properties of TeM. The C-terminal 120 amino acids of the human ChM-I precursor (Ad-shChM-I) was similarly expressed in HUVECs as a comparison study. Transduction of both Ad-shTeM and Ad-shChM-I resulted in significant impairment of the tube-forming activity of HUVECs, when cultured in Matrigel. Similarly, conditioned medium from COS7 cells, transfected with plasmid DNA encoding shTeM or shChM-I, inhibited tube formation of HUVECs when compared to medium derived from either COS7 cells transfected with control vector or from non-transfected cells. Upon infection of HUVECs with Ad-shTeM or Ad-shChM-I, DNA synthesis stimulated by vascular endothelial growth factor (VEGF) was reduced to 40-50% of normal levels. Additionally, in a modified Boyden chamber assay, migration of HUVECs in response to VEGF was significantly affected following transduction of either Ad-shTeM or Ad-shChM-I and these transduced HUVECs were found to spread well on type I collagen or fibronectin, but not on vitronectin. Furthermore, the transduction of either Ad-shTeM or Ad-shChM-I in human melanoma cells resulted in suppression of tumor growth in association with decreased vessel density in vivo. Hence, we have demonstrated that, similarly to ChM-1, the C-terminal domain of TeM exhibits both anti-angiogenic and anti-tumor activities when expressed in a secreted form.

Weight reduction modulates expression of genes involved in extracellular matrix and cell death: the GENOBIN study

“…Moreover, the expression of TNMD was associated with several characteristics of the metabolic syndrome. Tenomodulin has been suggested to mediate antiangiogenic activity, and its C-terminal extracellular domain modulates endothelial cell proliferation [50][51][52] indicating that it also might have a role in the function of ECM. It is also involved in collagen fibril maturation.…”

PRDM6 is enriched in vascular precursors during development and inhibits endothelial cell proliferation, survival, and differentiation

“…Aside from the PR-plus and PR-minus variants, there are multiple other isoforms that can be generated by alternative splicing or by alternative promoter usage. Many lines of investigation suggest that PRDM genes seem to have a dual function that follows a similar pattern: the PR-plus isoform behaves as tumor suppressor, while the PR-minus isoform functions as an oncogene since the PR-plus product is found disrupted or underexpressed whereas the PR-minus product is present or overexpressed in many types of cancer cells [20][21][22][23][24][25][26][27][28]. Here we reported the discovery of four more isoforms of PRDM6 in addition to the reported PRISM/PRDM6 [14].…”

“…After 12 h incubation, cells were observed under bright light and fluorescence microscope. Total tube length per field was measured and analyzed using Image J software [23,24].…”

Scx+/Sox9+ progenitors contribute to the establishment of the junction between cartilage and tendon/ligament

“…After washing, the sections were incubated with goat anti-rat and anti-rabbit secondary antibodies conjugated to Alexa Fluor 488 or with goat anti-rabbit and anti-mouse secondary antibodies conjugated to Alexa Fluor 594 (Molecular Probes), and washed again in PBS. The primary antibodies used were anti-GFP (diluted 1:1000; Nakarai), anti-Sox9 (1:600; Chemicon), anti-tenomodulin (Tnmd) (1:1000) (Oshima et al, 2004;Shukunami et al, 2008), anti-chondromodulin 1 (Chm1) (1:1000; Cosmo Bio) and anti-type I collagen (1:500; Rockland). Nuclei were counterstained with 4Ј,6-diamidino-2-phenylindole (DAPI).…”