American Society for Matrix Biology Subforums

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 6 March 2010

Pingping, He , Yan, Zhang , Seong Oh, Kim , Ralf J., Radlanski , Kristin, Butcher , ...

Tooth enamel is formed by epithelially-derived cells called ameloblasts, while the pulp dentin complex is formed by the dental mesenchyme. These tissues differentiate with reciprocal signaling interactions to form a mature tooth. In this study we have characterized ameloblast differentiation in human developing incisors, and have further investigated the role of extracellular matrix proteins on ameloblast differentiation. Histological and immunohistochemical analyses showed that in the human tooth, the basement membrane separating the early developing dental epithelium and mesenchyme was lost shortly before dentin deposition was initiated, prior to enamel matrix secretion. Presecretary ameloblasts elongated as they came into contact with...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 1 March 2010

Isabelle, Martelly , Dominique, Singabraya , Aurélie, Vandebrouck , Dulce, Papy-Garcia , Christian, Cognard , ...

Glycosaminoglycans (GAG) are sulfated polysaccharides that play an important role in regulating cell functions. GAG mimetics called RGTAs (for ReGeneraTing Agents) have been shown to stimulate tissue repair. In particular they accelerate myogenesis, in part via their heparin-mimetic property towards growth factors. RGTAs also increase activity of calcium-dependent intracellular protease suggesting an effect on calcium cellular homeostasis. This effect was presently investigated on myoblasts in vitro using one member of the RGTA family molecule named OTR4120. We have shown that OTR4120 or heparin induced transient increases of intracellular calcium concentration ([Ca2+]i) in pre-fusing myoblasts from both mouse SolD7 cell line...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 25 February 2010

Michael A., Chernousov , Kelly, Baylor , Richard C., Stahl , Mark M., Stecker , Lynn Y., Sakai , ...

The extracellular matrix of peripheral nerve is formed from a diverse set of macromolecules, including glycoproteins, collagens and proteoglycans. Recent studies using knockout animal models have demonstrated that individual components of the extracellular matrix play a vital role in peripheral nerve development and regeneration. In this study we identified fibrillin-1 and fibrillin-2, large modular structural glycoproteins, as components of the extracellular matrix of peripheral nerve. Previously it was found that fibrillin-2 null mice display joint contractures, suggesting a possible defect of the peripheral nervous system in these animals. Close examination of the peripheral nerves of fibrillin-2 deficient animals described here...

Publication year: 2010
Source: Matrix Biology, Volume 29, Issue 2, March 2010, Pages 87-88

[No author name available]

Publication year: 2010
Source: Matrix Biology, Volume 29, Issue 2, March 2010, Page 160

[No author name available]

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 14 February 2010

Francesca, Zito , Robert D., Burke , Valeria, Matranga

Pl-nectin is a component of the extracellular matrix that surrounds embryos of the sea urchin Paracentrotus lividus. Pl-nectin mediates adhesion of dissociated embryonic cells to substrates and interfering with ectodermic cells contacting Pl-nectin results in defects in skeleton growth and morphogenesis. Recently, we reported that Pl-nectin is a new member of the discoidin family, in agreement with the notion that many discoidin-containing proteins are involved in cell adhesion processes as integrin ligands. To better understand the molecular basis for the interaction of Pl-nectin with ectoderm, we investigated the hypothesis that Pl-nectin is an integrin ligand in sea urchin embryos. We...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 12 February 2010

P.W., Kopesky , H.-Y., Lee , E.J., Vanderploeg , J.D., Kisiday , D.D., Frisbie , ...

Our objective was to evaluate the age-dependent mechanical phenotype of bone marrow stromal cell- (BMSC-) and chondrocyte-produced cartilage-like neotissue and to elucidate the matrix-associated mechanisms which generate this phenotype. Cells from both immature (2-4 month-old foals) and skeletally-mature (2-5 year-old adults) mixed-breed horses were isolated from animal-matched bone marrow and cartilage tissue, encapsulated in self-assembling-peptide hydrogels, and cultured with and without TGF-β1 supplementation. BMSCs and chondrocytes from both donor ages were encapsulated with high viability. BMSCs from both ages produced neo-tissue with higher mechanical stiffness than that produced by either young or adult chondrocytes. Young, but not adult, chondrocytes proliferated...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 12 February 2010

Daniel J., Leong , Xiang I., Gu , Yonghui, Li , Jonathan Y., Lee , Damien M., Laudier , ...

Both underloading and overloading of joints can lead to articular cartilage degradation, a process mediated in part by matrix metalloproteinases (MMPs). Here we examine the effects of reduced loading of rat hindlimbs on articular cartilage expression of MMP-3, which not only digests matrix components but also activates other proteolytic enzymes. We show that hindlimb immobilization resulted in elevated mRNA expression at 6 hours that was sustained throughout the 21day immobilization period. MMP-3 upregulation was higher in the medial condyle than the lateral, and was greatest in the superficial cartilage zone, followed by middle and deep zones. These areas also showed...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 6 February 2010

Helen K., Graham , Nigel W., Hodson , Judith A., Hoyland , Sarah J., Millward-Sadler , David, Garrod , ...

Conventional approaches for ultrastructural high resolution imaging of biological specimens induce profound changes in bio-molecular structures. By combining tissue cryo-sectioning with non-destructive atomic force microscopy (AFM) imaging we have developed a methodology that may be applied by the non-specialist to both preserve and visualize biomolecular structures (in particular extracellular matrix assemblies) in situ. This tissue section AFM technique is capable of: i) resolving nm-μm scale features of intra- and extra-cellular structures in tissue cryosections; ii) imaging the same tissue region before and after experimental interventions; iii) combining ultrastructural imaging with complimentary microscopical and micromechanical methods. Here, we employ this technique...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 4 February 2010

Li, Kong , Qingyun, Tian , Fengjin, Guo , Maria T., Mucignat , Roberto, Perris , ...

In an effort to define the biological functions of COMP, a functional genetic screen was performed. This led to the identification of extracellular matrix protein 1 (ECM1) as a novel COMP-associated partner. COMP directly binds to ECM1 both in vitro and in vivo. The EGF domain of COMP and the C-terminus of ECM1 mediate the interaction between them. COMP and ECM1 Colocalize in the Growth Plates in Vivo. ECM1 inhibits chondrocyte hypertrophy, matrix mineralization, and endochondral bone formation, and COMP overcomes the inhibition by ECM1. In addition, COMP-mediated neutralization of ECM1 inhibition depends on their interaction, since COMP largely fails...

Publication year: 2010
Source: Matrix Biology, In Press, Accepted Manuscript, Available online 25 January 2010

Guy G., Hoffman , Amanda M., Branam , Guorui, Huang , Francisco, Pelegri , William G., Cole , ...

Genes for tetrapod fibrillar procollagen chains can be divided into two clades, A and B, based on sequence homologies and differences in protein domain and gene structures. Although the major fibrillar collagen types I-III comprise only clade A chains, the minor fibrillar collagen types V and XI comprise both clade A chains and the clade B chains pro-α1(V), pro-α3(V), pro-α1(XI) and pro-α2(XI), in which defects can underlie various genetic connective tissue disorders. Here we characterize the clade B procollagen chains of zebrafish. We demonstrate that in contrast to the four tetrapod clade B chains, zebrafish have six clade B chains,...