Collagen Research Papers - Academia.edu (original) (raw)

Transforming growth factor type (3 (TGF-f3), when injected subcutaneously in newborn mice, causes forma-tion of granulation tissue (induction of angiogenesis and acti-vation of fibroblasts to produce collagen) at the site of injection.... more

Transforming growth factor type (3 (TGF-f3), when injected subcutaneously in newborn mice, causes forma-tion of granulation tissue (induction of angiogenesis and acti-vation of fibroblasts to produce collagen) at the site of injection. These effects occur within 2-3 days at dose ...

The relationship of cell proliferation to the temporal expression of genes characterizing a developmental sequence associated with bone cell differentiation was examined in primary diploid cultures of fetal calvarial derived osteoblasts... more

The relationship of cell proliferation to the temporal expression of genes characterizing a developmental sequence associated with bone cell differentiation was examined in primary diploid cultures of fetal calvarial derived osteoblasts by the combined use of autoradiography, ...

We investigated the functions of adiponectin, an adipocyte-specific secretory protein and a new member of the family of soluble defense collagens, in hematopoiesis and immune responses. Adiponectin suppressed colony formation from... more

We investigated the functions of adiponectin, an adipocyte-specific secretory protein and a new member of the family of soluble defense collagens, in hematopoiesis and immune responses. Adiponectin suppressed colony formation from colony-forming units (CFU)-granulocyte-macrophage, CFU-macrophage, and CFU-granulocyte, whereas it had no effect on that of burst-forming units-erythroid or mixed erythroid-myeloid CFU. In addition, adiponectin inhibited proliferation of 4 of 9 myeloid cell lines but did not suppress proliferation of erythroid or lymphoid cell lines except for one cell line. These results suggest that adiponectin predominantly inhibits proliferation of myelomonocytic lineage cells. At least one mechanism of the growth inhibition is induction of apoptosis because treatment of acute myelomonocytic leukemia lines with adiponectin induced the appearance of subdiploid peaks and oligonucleosomal DNA fragmentation. Aside from inhibiting growth of myelomonocytic progenitors, adipo...

Carbon nanotubes focus the attention of many scientists because of their huge potential of industrial applications, but there is a paucity of information on the toxicological properties of this material. The aim of this experimental study... more

Carbon nanotubes focus the attention of many scientists because of their huge potential of industrial applications, but there is a paucity of information on the toxicological properties of this material. The aim of this experimental study was to characterize the biological reactivity of purified multi-wall carbon nanotubes in the rat lung and in vitro. Multi-wall carbon nanotubes (CNT) or ground CNT were administered intratracheally (0.5, 2 or 5 mg) to Sprague–Dawley rats and we estimated lung persistence, inflammation and fibrosis biochemically and histologically. CNT and ground CNT were still present in the lung after 60 days (80% and 40% of the lowest dose) and both induced inflammatory and fibrotic reactions. At 2 months, pulmonary lesions induced by CNT were characterized by the formation of collagen-rich granulomas protruding in the bronchial lumen, in association with alveolitis in the surrounding tissues. These lesions were caused by the accumulation of large CNT agglomerates in the airways. Ground CNT were better dispersed in the lung parenchyma and also induced inflammatory and fibrotic responses. Both CNT and ground CNT stimulated the production of TNF-α in the lung of treated animals. In vitro, ground CNT induced the overproduction of TNF-α by macrophages. These results suggest that carbon nanotubes are potentially toxic to humans and that strict industrial hygiene measures should to be taken to limit exposure during their manipulation.

The extracellular matrix (ECM) may contribute to the drug resistance of a solid tumor by preventing the penetration of therapeutic agents. We measured differences in interstitial resistance to macromolecule (IgG) motion in four tumor... more

The extracellular matrix (ECM) may contribute to the drug resistance of a solid tumor by preventing the penetration of therapeutic agents. We measured differences in interstitial resistance to macromolecule (IgG) motion in four tumor types and found an unexpected correspondence between transport resistance and the mechanical stiffness. The interstitial diffusion coefficient of IgG was measured in situ by fluorescence redistribution after photobleaching. Tissue elastic modulus and hydraulic conductivity were measured by confined compression of excised tissue. In apparent contradiction to an existing paradigm, these functional properties are correlated with total tissue content of collagen, not glycosaminoglycan. An extended collagen network was observed in the more penetration-resistant tumors. Collagenase treatment of the more penetration-resistant tumors significantly increased the IgG interstitial diffusion rate. We conclude that collagen influences the tissue resistance to macrom...

We demonstrate the direct involvement of increased colla-genase activity in the cleavage of type II collagen in osteo-arthritic human femoral condylar cartilage by developing and using antibodies reactive to carboxy-terminal (COL2-3/... more

We demonstrate the direct involvement of increased colla-genase activity in the cleavage of type II collagen in osteo-arthritic human femoral condylar cartilage by developing and using antibodies reactive to carboxy-terminal (COL2-3/ 4Cshort) and amino-terminal ...

Basement membranes are specialized extracellular matrices with support, sieving, and cell regulatory functions. The molecular architectures of these matrices are created through specific binding interactions between unique glycoprotein... more

Basement membranes are specialized extracellular matrices with support, sieving, and cell regulatory functions. The molecular architectures of these matrices are created through specific binding interactions between unique glycoprotein and proteoglycan protomers. Type IV collagen chains, using NH2-terminal, COOH-terminal, and lateral association, form a covalently stabilized polygonal framework. Laminin, a four-armed glycoprotein, self-assembles through terminal-domain interactions to form a second polymer network, Entactin/nidogen, a dumbbell-shaped sulfated glycoprotein, binds laminin near its center and interacts with type IV collagen, bridging the two. A large heparan sulfate proteoglycan, important for charge-dependent molecular sieving, is firmly anchored in the basement membrane and can bind itself through a core-protein interaction to form dimers and oligomers and bind laminin and type IV collagen through its glycosaminoglycan chains. Heterogeneity of structure and function ...