Extracellular Matrix Proteins

Despite remarkable developments in vascular medicine in the last decades and intensive research on the improvement of bypass materials, an ideal bypass graft comparable to autologous veins or arteries is still not available for peripheral vascular and coronary artery bypass grafting. This article reviews established bypass materials and provides an overview over interesting new technologies particularly those associated with tissue-engineering and those already adopted clinically.

Pancreatic cancer is a rapidly fatal disease, and there is an urgent need for early detection markers and novel therapeutic targets. The current study has used a proteomic approach of two-dimensional (2D) gel electrophoresis and mass spectrometry (MS) to identify differentially expressed ...

Tumors evade host immunity at both the induction and effector phases. Most studies have focused on tumor evasion at the induction phase, and, due in part to poor antitumor CTL responses to most tumors, the mech- anism for evasion of CTL effector function is less clear. Here we have taken advantage of the strong CTL responses to a costimulator B7-1- transfected tumor to study the mechanism for tumor evasion of preexist- ing host immunity. We have investigated six independent recurrent tu- mors isolated from mice that were challenged with and had rejected B7-1-transfected J558 (J558-B7) tumors. Because the mice had developed strong antitumor CTL responses, these recurrent tumors must have evaded preexisting antitumor CTLs. Indeed, whereas the parental J558-B7 cell line is efficiently lysed by the ex vivo tumor-infiltrating lymphocytes, all of the recurrent tumors are resistant to such lysis. Interestingly, the recurrent tumors can be divided into two groups. The group 1 tumors have va...

This chapter describes the production of micropatterns of extracellular matrix proteins on a 2D flat polyacrylamide (PAA) gel. The technique is divided into two parts. First, micropatterns are produced on glass or directly on a photomask using deep UV. Then the micropatterns are transferred on acrylamide gel by polymerization of the gel directly on the template coverslip. This procedure is easy to perform and does not require any expensive equipment. It can be performed in no more than 2h once you get your hands on it. It combines the advantages of other existing techniques: good spatial resolution, suitable for very soft gel, no need for the use of chemical crosslinkers for attachment of the proteins to the acrylamide, no modification of the mechanical properties of the gel by the process, and suitable for multiple protein patterning. We also discuss the storage issues of such substrates and provide a brief review of other existing techniques for micropatterning on PAA.

The aim of this study is to elucidate the role of integrins in transducing fluid shear stress into intracellular signals in vascular endothelial cells, a fundamental process in vascular biology. We demonstrated that shear stress activates specific integrins in endothelial cells plated on substrates containing the cognate extracellular matrix (ECM) ligands. The shear stress-induced mechanotransduction, as manifested by integrin-Shc association,

While pseudoachondroplasia (PSACH) is almost exclusively caused by cartilage oligomeric matrix protein (COMP) mutations, many patients identified with the PSACH phenotype do not have this mutation, suggesting gene and locus heterogeneity. In order to further characterize this entity, we studied 32 clinically and radiographically diagnosed PSACH patients, among 19 families. COMP and collagen (Col) IX (A1, A2 and A3) mutations, were determined. Patients who tested negative for pathological gene mutations but who were identified with the PSACH phenotype, were included. The phenotypes were characterized according to height deviation (cm) from normal, lower extremity mechanical axis deviation (MAD), cervical and thoracolumbar spine involvement, pelvic index, as well as hip, knee, ankle and hand involvement. We report an 81% mutation detection rate for PSACH, of which COMP+Col9A3 mutations were more prevalent (61%) than COMP mutations alone (30%). Of our PSACH patients, 19% tested negativ...

Although the precise mechanisms of the conversion of predentin to dentin are not well understood, several lines of evidence implicate the noncollagenous proteins (NCPs) as important regulators of dentin biomineralization. Here we compared the in vivo temporospatial expression patterns of two dentin NCP genes, dentin matrix protein 1 (Dmp1), and dentin sialophosphoprotein (DSPP) in developing molars. Reverse transcription-polymerase chain reaction was performed on embryonic day 13 to 1-day-old first molars using Dmp1- and DSPP-specific primer sets. Dmp1 transcripts appeared at the late bud stage, while DSPP mRNA was seen at the cap stage. Expression of both genes was sustained throughout odontogenesis. In situ hybridization analysis revealed interesting differences in the expression patterns of these genes. While Dmp1 and DSPP showed coexpression in young odontoblasts before the start of mineralization, the expression of these genes was notably distinct at later stages. Dmp1 expression decreased in secretory odontoblasts after the appearance of mineral, while high levels of DSPP were sustained in odontoblasts. In early secretory ameloblasts, DSPP expression was transient and down-regulated with the appearance of dentin matrix. Interestingly, Dmp1 expression became evident in ameloblasts during the maturative phase of amelogenesis. In contrast to Dspp expression that was tooth-specific, Dmp1 was expressed by osteoblasts throughout ossification in the skeleton. Probes directed to the “DSP” and “DPP” regions of the DSPP gene showed identical patterns of mRNA expression. These data show that the developmental expression patterns of Dmp1 and DSPP are distinct, implying that these molecules serve different biological functions in vivo.

Mechanical loading has been shown to modulate longitudinal bone growth and cellular activity of the growth plate. Nevertheless, limited and controversial results exist regarding the effect of exercise on a physiological level on the growth plate. The present study investigated whether dose-dependent voluntary exercise has an influence on morphological, biochemical, and mechanical factors of the distal femoral growth plate of

During mammalian brain development, neurons are generated along the ventricle, migrate radially, and become aligned in defined patterns. These precise patterns of neuronal alignment are regulated by an extracellular matrix protein Reelin, and binding of Reelin to its receptors induces tyrosine phosphorylation of the intracellular adaptor protein disabled 1 (Dab1). We recently reported that Reelin molecules assemble to form a homomeric protein complex. Although the number of molecules in the full-length complex is unknown, recombinant N-terminal fragments, which contain the epitope for the function-blocking CR-50 antibody, assembled to form a complex of more than 40 monomers. When the N-terminus was deleted from Reelin, the truncated protein did not form a stable complex. To further characterize the Reelin assembly, we performed biochemical analysis of the full-length Reelin assembly in this study. Here, we report that a full-length Reelin forms a disulfide-linked homodimer. A chemic...

Odontogenic ameloblast-associated protein (ODAM) has been shown to be specifically expressed in ameloblasts and odontoblasts and has been suggested to play a role in the mineralization of the enamel, possibly through the regulation of matrix metalloproteinase 20. However, its function in dentin is not clear. The purpose of this study was to evaluate the effect of ODAM on tertiary dentin formation. MDPC-23 odontoblastic cells were cultured, and the effect of recombinant ODAM (rODAM) on mineralized nodule formation was evaluated. Pinpoint pulp exposures were made in rat teeth and then capped with rODAM mixed with a carrier (rODAM group), carrier only (Carrier group), or white mineral trioxide aggregate (WMTA group). After 1, 2, and 4 weeks, odontoblasts and tertiary dentin were investigated histologically and immunohistochemically. Nodule formation in MDPC-23 cells was enhanced by rODAM treatment. Odontoblasts were polarized and showed a palisade arrangement in the remaining pulp from...