+1 Recommend
0 collections
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Syndecan-1 Regulates Vascular Smooth Muscle Cell Phenotype

      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.



          We examined the role of syndecan-1 in modulating the phenotype of vascular smooth muscle cells in the context of endogenous inflammatory factors and altered microenvironments that occur in disease or injury-induced vascular remodeling.

          Methods and Results

          Vascular smooth muscle cells (vSMCs) display a continuum of phenotypes that can be altered during vascular remodeling. While the syndecans have emerged as powerful and complex regulators of cell function, their role in controlling vSMC phenotype is unknown. Here, we isolated vSMCs from wild type (WT) and syndecan-1 knockout (S1KO) mice. Gene expression and western blotting studies indicated decreased levels of α-smooth muscle actin (α-SMA), calponin, and other vSMC-specific differentiation markers in S1KO relative to WT cells. The spread area of the S1KO cells was found to be greater than WT cells, with a corresponding increase in focal adhesion formation, Src phosphorylation, and alterations in actin cytoskeletal arrangement. In addition, S1KO led to increased S6RP phosphorylation and decreased AKT and PKC-α phosphorylation. To examine whether these changes were present in vivo, isolated aortae from aged WT and S1KO mice were stained for calponin. Consistent with our in-vitro findings, the WT mice aortae stained higher for calponin relative to S1KO. When exposed to the inflammatory cytokine TNF-α, WT vSMCs had an 80% reduction in syndecan-1 expression. Further, with TNF-α, S1KO vSMCs produced increased pro-inflammatory cytokines relative to WT. Finally, inhibition of interactions between syndecan-1 and integrins αvβ3 and αvβ5 using the inhibitory peptide synstatin appeared to have similar effects on vSMCs as knocking out syndecan-1, with decreased expression of vSMC differentiation markers and increased expression of inflammatory cytokines, receptors, and osteopontin.


          Taken together, our results support that syndecan-1 promotes vSMC differentiation and quiescence. Thus, the presence of syndecan-1 would have a protective effect against vSMC dedifferentiation and this activity is linked to interactions with integrins αvβ3 and αvβ5.

          Related collections

          Most cited references 29

          • Record: found
          • Abstract: found
          • Article: not found

          Nanoscale architecture of integrin-based cell adhesions.

          Cell adhesions to the extracellular matrix (ECM) are necessary for morphogenesis, immunity and wound healing. Focal adhesions are multifunctional organelles that mediate cell-ECM adhesion, force transmission, cytoskeletal regulation and signalling. Focal adhesions consist of a complex network of trans-plasma-membrane integrins and cytoplasmic proteins that form a <200-nm plaque linking the ECM to the actin cytoskeleton. The complexity of focal adhesion composition and dynamics implicate an intricate molecular machine. However, focal adhesion molecular architecture remains unknown. Here we used three-dimensional super-resolution fluorescence microscopy (interferometric photoactivated localization microscopy) to map nanoscale protein organization in focal adhesions. Our results reveal that integrins and actin are vertically separated by a ∼40-nm focal adhesion core region consisting of multiple protein-specific strata: a membrane-apposed integrin signalling layer containing integrin cytoplasmic tails, focal adhesion kinase and paxillin; an intermediate force-transduction layer containing talin and vinculin; and an uppermost actin-regulatory layer containing zyxin, vasodilator-stimulated phosphoprotein and α-actinin. By localizing amino- and carboxy-terminally tagged talins, we reveal talin's polarized orientation, indicative of a role in organizing the focal adhesion strata. The composite multilaminar protein architecture provides a molecular blueprint for understanding focal adhesion functions.
            • Record: found
            • Abstract: found
            • Article: not found

            Synergistic control of cell adhesion by integrins and syndecans.

            The ability of cells to adhere to each other and to their surrounding extracellular matrices is essential for a multicellular existence. Adhesion provides physical support for cells, regulates cell positioning and enables microenvironmental sensing. The integrins and the syndecans are two adhesion receptor families that mediate adhesion, but their relative and functional contributions to cell-extracellular matrix interactions remain obscure. Recent advances have highlighted connections between the signalling networks that are controlled by these families of receptors. Here we survey the evidence that synergistic signalling is involved in controlling adhesive function and the regulation of cell behaviour in response to the external environment.
              • Record: found
              • Abstract: found
              • Article: not found

              Syndecans: new kids on the signaling block.

              Cell-associated proteoglycans provide highly complex and sophisticated systems to control interactions of extracellular cell matrix components and soluble ligands with the cell surface. Syndecans, a conserved family of heparan- and chondroitin-sulfate carrying transmembrane proteins, are emerging as central players in these interactions. Recent studies have demonstrated the essential role of syndecans in modulating cellular signaling in embryonic development, tumorigenesis, and angiogenesis. In this review, we focus on new advances in our understanding of syndecan-mediated cell signaling.

                Author and article information

                Role: Editor
                PLoS One
                PLoS ONE
                PLoS ONE
                Public Library of Science (San Francisco, USA )
                25 February 2014
                : 9
                : 2
                Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, United States of America
                Texas A & M, Division of Cardiology, United States of America
                Author notes

                Competing Interests: The authors have declared that no competing interests exist.

                Conceived and designed the experiments: SC AB. Performed the experiments: SC CL DH DP. Analyzed the data: SC DH AB. Contributed reagents/materials/analysis tools: AB. Wrote the paper: SC AB.


                This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

                Page count
                Pages: 12
                This study was supported by the American Heart Association (10SDG2630139) and the National Institutes of Health (1DP2OD008716-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
                Research Article
                Extracellular matrix proteins
                Molecular cell biology
                Cell adhesion
                Signal transduction
                Signaling in cellular processes
                Extracellular matrix signaling
                Cellular stress responses
                Extracellular matrix
                Gene expression
                Biomedical engineering
                Materials science
                Vascular biology



                Comment on this article