Distribution of PG-M/Versican Variants in Human Tissues andde Novo Expression of Isoform V3 upon Endothelial Cell Activation, Migration, and Neoangiogenesis in Vitro

Abstract

We have carried out a comprehensive molecular mapping of PG-M/versican isoforms V0 -V3 in adult human tissues and have specifically investigated how the expression of these isoforms is regulated in endothelial cells in vitro. A survey of 21 representative tissues highlighted a prevalence of V1 mRNA; demonstrated that the relative frequency of expression was V1 > V2 > V3 > V2; and showed that <15% of the tissues transcribed significant levels of all four isoforms. By employing novel and previously described anti-versican antibodies we verified a ubiquitous versican deposition in normal and tumor-associated vascular structures and disclosed differences in the glycanation profiles of versicans produced in different vascular beds. Resting endothelial cells isolated from different tissue sources transcribed several of the versican isoforms but consistently failed to translate these mRNAs into detectable proteoglycans. However, if stimulated with tumor necrosis factor-␣ or vascular endothelial growth factor, they altered their versican expression by de novo transcribing the V3 isoform and by exhibiting a moderate V1/V2 production. Induced versican synthesis and de novo V3 expression was also observed in endothelial cells elicited to migrate in a wound-healing model in vitro and in angiogenic endothelial cells forming tubule-like structures in Matrigel or fibrin clots. The results suggest that, independent of the degree of vascularization, human adult tissues show a limited expression of versican isoforms V0, V2, and V3 and that endothelial cells may contribute to the deposition of versican in vascular structures, but only following proper stimulation.

The Roles of Versican V1 and V2 Isoforms in Cell Proliferation and Apoptosis

“…It is distributed in a wide variety of tissues during development and is also associated with tissue injury (Landolt et al, 1995). Our data and those of others have shown that versican plays a role in cell adhesion, migration, proliferation, and differentiation (Landolt et al, 1995;Henderson et al, 1997;Zhang et al, 1998aZhang et al, , 1998bAng et al, 1999;Cattaruzza et al, 2002Cattaruzza et al, , 2004.…”

“…This balanced extracellular environment might be altered by modifying the distribution of various versican isoforms. The extracellular environment may become favorable for cell proliferation and survival when V1 expression is increased, as in the case of tissue development and tumor formation (Landolt et al, 1995;Cattaruzza et al, 2002;Touab et al, 2002). By contrast, a V2-predominant environment may suppress cell proliferation, as in the case of maintenance of mature tissues.…”

The role of versican isoforms V0/V1 in glioma migration mediated by transforming growth factor-β2

“…The specific primers for the PCR amplification of versican isoforms were used as described before (Cattaruzza et al, 2002). The sizes of the amplification products were 405 bp for the V0 splice form (forward: 5 0 -TCAACATCTCATGTTCCTCCC-3 0 and reverse: 5 0 -TTCTTCACTGTG GGTATAGGTCTA-3 0 ), 336 bp for V1 (forward: 5 0 -GGCTTTGACCAGTGCGATTAC-3 0 ; reverse: 5 0 -TTCTTCACTGTGGGTATAGGTCTA-3 0 ), 498 bp for V2 (forward: 5 0 -TCAACA TCTCATGTTCCTCCC-3 0 ; reverse: 5 0 -CCAGCCATA GTCACA TGTCTC-3 0 ) and 429 bp for V3 (forward: 5 0 -GGCTTTGACCAGTGCGATTAC-3 0 ; reverse: 5 0 -CCAGCCATAGT CACATGTCTC-3 0 ).…”

Versican Degradation and Vascular Disease

“…All forms of versican share the remaining domains that include the amino-terminal globular domain (G1; which contains the hyaluronan-binding link modules) and the carboxy-terminal G3 domain (which contains two EGF-like repeats, a complement-regulatory protein-like repeat [CRP], and a C-type lectin domain [LC]). In the blood vessel wall, in which versican is a major proteoglycan, V0 (with both αGAG and βGAG domains), V1 (only the βGAG domain), V2 (only the αGAG domain), and V3 (neither GAG domain) have all been reported to be expressed (Lemire et al 1999, Cattaruzza et al 2002.…”