Multivalent proteoglycan modulation of FGF mitogenic responses in perivascular cells
- PDF / 1,142,807 Bytes
- 19 Pages / 595.276 x 790.866 pts Page_size
- 61 Downloads / 193 Views
ORIGINAL PAPER
Multivalent proteoglycan modulation of FGF mitogenic responses in perivascular cells Sabrina Cattaruzza • Ugur Ozerdem • Martin Denzel • Barbara Ranscht Pietro Bulian • Ugo Cavallaro • Daniela Zanocco • Alfonso Colombatti • William B. Stallcup • Roberto Perris
•
Received: 19 May 2012 / Accepted: 12 October 2012 / Published online: 4 November 2012 Ó Springer Science+Business Media Dordrecht 2012
Abstract Sprouting of angiogenic perivascular cells is thought to be highly dependent upon autocrine and paracrine growth factor stimulation. Accordingly, we report that corneal angiogenesis induced by ectopic FGF implantation is strongly impaired in NG2/CSPG4 proteoglycan (PG) null mice known to harbour a putative deficit in pericyte proliferation/mobilization. Conversely, no significant differences were seen between wild type and knockout corneas when VEGF was used as an angiocrine factor. Perturbed responsiveness of NG2-deficient pericytes to paracrine and autocrine stimulation by several FGFs could be confirmed in cells isolated from NG2 null mice, while proliferation induced by other growth factors was equivalent in wild type
and knockout cells. Identical results were obtained after siRNA-mediated knock-down of NG2 in human smooth muscle-like cell lines, as also demonstrated by the decreased levels of FGF receptor phosphorylation detected in these NG2 deprived cells. Binding assays with recombinant proteins and molecular interactions examined on live cells asserted that FGF-2 bound to NG2 in a glycosaminoglycanindependent, core protein-mediated manner and that the PG was alone capable of retaining FGF-2 on the cell membrane for subsequent receptor presentation. The use of dominantnegative mutant cells, engineered by combined transduction of NG2 deletion constructs and siRNA knock-down of the endogenous PG, allowed us to establish that the FGF coreceptor activity of NG2 is entirely mediated by its extracellular portion. In fact, forced overexpression of the NG2
Electronic supplementary material The online version of this article (doi:10.1007/s10456-012-9316-7) contains supplementary material, which is available to authorized users. S. Cattaruzza D. Zanocco A. Colombatti R. Perris (&) S.O.C. for Experimental Oncology 2, The National Cancer Institute Aviano, CRO-IRCCS, Via Pedemontana Occidentale 12, 33081 Aviano, PN, Italy e-mail: [email protected] S. Cattaruzza e-mail: [email protected] U. Ozerdem La Jolla Bioengineering Institute, 505 Coast Blvd, La Jolla, CA 92037, USA e-mail: [email protected] M. Denzel B. Ranscht W. B. Stallcup The Sanford-Burnham Institute for Medical Research, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA e-mail: [email protected]
W. B. Stallcup e-mail: [email protected] P. Bulian S.O.C. for Experimental and Clinical Onco-Hematology, The National Cancer Institute Aviano, CRO-IRCCS, Via Pedemontana Occidentale 12, Aviano, PN 33081, Italy e-mail: [email protected] U. Cavallaro IFOM-IEO Campus, The FIRC Institute of Molecular Oncology, Via Adamello 16,
Data Loading...
