Research Interests: Kinetics, Biology, Cell Migration, Cell Adhesion, Cell Biology, and 15 moreBiological Chemistry, Medicine, Biological Sciences, Cell line, Humans, Animals, Biological, Chemotaxis, CHEMICAL SCIENCES, Neurite, Amino Acid Sequence, Axons, Laminin, Molecular Sequence Data, and Medical and Health Sciences
Cutis laxa is a genetically heterogeneous connective tissue disease that occurs in both inherited and acquired forms. The most apparent defect is loose, redundant, nonresilient skin, but systemic connective tissue abnormalities exist,... more
Cutis laxa is a genetically heterogeneous connective tissue disease that occurs in both inherited and acquired forms. The most apparent defect is loose, redundant, nonresilient skin, but systemic connective tissue abnormalities exist, especially in conjunction with the early onset or autosomal recessive variety. The elastic fiber shows morphologic alterations. We studied dermal skin biopsies and cultured skin fibroblasts from 6 patients with congenital forms of cutis laxa in an effort to correlate alterations in elastin morphology and metabolism. In general, ultrastructural analysis revealed occasional variance in collagen fiber diameter, whereas elastic tissue varied in content, appearance, and the proportion and manner by which elastin and microfibrillar component associated. Fibroblast cell lines comprised of normal donors from
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Hutchinson-Gilford progeria is a unique, rare disease with markedly accelerated aging. The average lifespan of affected individuals is 12 years. Although the biochemical basis of the syndrome is unknown, its influence appears to be... more
Hutchinson-Gilford progeria is a unique, rare disease with markedly accelerated aging. The average lifespan of affected individuals is 12 years. Although the biochemical basis of the syndrome is unknown, its influence appears to be primarily upon mesodermal tissues. Characteristics such as the altered appearance of the skin and the extensive and fatal involvement of the cardiovascular system led us to study elastin production in cultured skin fibroblasts from three progeroid individuals. We found tropoelastin production by progeroid cells was elevated six- to nine-fold at the protein and mRNA levels, while relative collagen synthesis was similar to control strains. There was little difference between progeroid and normal cells in expression of total protein or in total cellular mRNA content. Western blot analysis of tropoelastin from progeroid fibroblasts confirmed increased production of elastin but revealed no gross changes in the molecular mass. The significant increase in tropoelastin expression lends support to the concept that progeria results from a mesenchymal dysplasia, and offers a possible biochemical marker for the phenotype.
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Page 1. Laminin in Neuronal Development HYNDA K. KLEINMAN, GREGORY c. SEPHEL,~ KEN-ICHIRO TASHIRO, BENJAMIN S. WEEKS, BETH A. BURROUS, SCOTT H. ADLER, YOSHIHIKO YAMADA, AND GEORGE R. MARTIN ...
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Extracellular matrix components when used as a substratum in vitro can greatly influence cell behavior. The response observed is dependent on the type of cell and matrix used. Cells in vitro usually respond best to the matrix components... more
Extracellular matrix components when used as a substratum in vitro can greatly influence cell behavior. The response observed is dependent on the type of cell and matrix used. Cells in vitro usually respond best to the matrix components with which they are normally in contact in vivo. More differentiated phenotypes are observed and cells generally survive longer on such matrices. In some cases, the presence of such matrices allows cells to be cultured in the absence of serum and growth factors. As more investigators try the matrices and matrix components described, as well as new components and combinations of them, it is anticipated that improvement in the culture of many cells can be expected.
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Observations regarding the repair of wounds (i.e., wound healing) date to physicians in ancient Egypt and battle surgeons in classic Greece. The liver’s ability to regenerate forms the basis of the Greek myth involving Prometheus. The... more
Observations regarding the repair of wounds (i.e., wound healing) date to physicians in ancient Egypt and battle surgeons in classic Greece. The liver’s ability to regenerate forms the basis of the Greek myth involving Prometheus. The clotting of blood to prevent exsanguination was recognized as the first necessary event in wound healing. At the time of the American Civil War, the development of “laudable pus” in wounds was thought to be necessary, and its emergence was not appreciated as a symptom of infection but considered a positive sign in the healing process. Later studies of wound infection led to the discovery that inflammatory cells are primary actors in the repair process. Although scurvy (see Chapter 8) was described in the 16th century by the British navy, it was not until the 20th century that vitamin C (ascorbic acid) was found to be necessary for the function of prolyl hydroxylase, an enzyme required for proper folding and stabilization of collagen into a triple helix...
Cutis laxa is a genetically heterogeneous connective tissue disease that occurs in both inherited and acquired forms. The most apparent defect is loose, redundant, nonresilient skin, but systemic connective tissue abnormalities exist,... more
Cutis laxa is a genetically heterogeneous connective tissue disease that occurs in both inherited and acquired forms. The most apparent defect is loose, redundant, nonresilient skin, but systemic connective tissue abnormalities exist, especially in conjunction with the early onset or autosomal recessive variety. The elastic fiber shows morphologic alterations. We studied dermal skin biopsies and cultured skin fibroblasts from 6 patients with congenital forms of cutis laxa in an effort to correlate alterations in elastin morphology and metabolism. In general, ultrastructural analysis revealed occasional variance in collagen fiber diameter, whereas elastic tissue varied in content, appearance, and the proportion and manner by which elastin and microfibrillar component associated. Fibroblast cell lines comprised of normal donors from
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Laminin is a large basement membrane glycoprotein which influences the behavior and morphology of a variety of cells. We have found that laminin and a pepsin fragment of laminin (P-lam) contain distinct sites for HT-1080 human... more
Laminin is a large basement membrane glycoprotein which influences the behavior and morphology of a variety of cells. We have found that laminin and a pepsin fragment of laminin (P-lam) contain distinct sites for HT-1080 human fibrosarcoma cell attachment and for neurite outgrowth activity of PC12 and NG108-15 cell lines. Reduction and alkylation of laminin and P-lam fragment disulfide bonds, in the absence of denaturing agents, markedly reduced the cell attachment activity without reducing the neurite outgrowth response. The P-lam fragment (approximately 375 kDa) was found to contain part of the cross region of laminin and a portion of the long arm, on the basis of recognition by antisera against laminin synthetic peptides and fusion proteins. Modification of arginine residues by cyclohexanedione also had no effect on neurite outgrowth but reduced HT-1080 cell adhesion. Modification of lysine residues by succinic and citraconic anhydride, however, abolished laminin neurite outgrowth but not cell attachment activity. Neurite outgrowth activity was recovered by reversing the lysine modification. These data support the existence on laminin of separate sites for cell attachment and for neurite outgrowth.
Research Interests: Developmental Biology, Cell Adhesion, Western blotting, Biological Sciences, Heparin, and 13 moreAnimals, Neurons, Rats, Protein Conformation, Alkylation, Molecular weight, Structure activity Relationship, Biological Assay, Oxidation-Reduction, Laminin, binding sites, Medical and Health Sciences, and In Vitro Techniques
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ABSTRACT
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Research Interests: Wound Healing, Immunohistochemistry, Western blotting, In Situ Hybridization, Vasculogenesis, and 15 moreBiological Sciences, Capillaries, Basement Membrane, Collagen, Animals, Male, Vascular endothelium, Steady state, Proteoglycans, Rats, Polyvinyl alcohol, Endothelial cell, Time Factors, Matrix Biology, and Laminin
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The process of neurite extension is complex and mechanisms involved probably vary depending on the local microenvironment (tissue site, extracellular matrix, neighboring cells, humoral factors, and developmental stage) of the developing... more
The process of neurite extension is complex and mechanisms involved probably vary depending on the local microenvironment (tissue site, extracellular matrix, neighboring cells, humoral factors, and developmental stage) of the developing or repairing neuron. Laminin contains at least one and perhaps more sites capable of stimulating process formation in a variety of neuronal cell types. This site contains a lysine and is likely located near a complex sugar residue. A complex of laminin and heparan sulfate proteoglycan appears to form a unique site with comparable activity, which is defined by monoclonal antibody recognition. Cell receptor complexes capable of recognizing the fibronectin cell attachment peptide RGD also bind laminin, while antisera to these complexes inhibit neurite outgrowth in some instances. The identification of laminin active sites and corresponding cell receptors could open new approaches to improving nerve regeneration in both the peripheral and central nervous system.
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Laminin is a large basement membrane glycoprotein which influences the behavior and morphology of a variety of cells. We have found that laminin and a pepsin fragment of laminin (P-lam) contain distinct sites for HT-1080 human... more
Laminin is a large basement membrane glycoprotein which influences the behavior and morphology of a variety of cells. We have found that laminin and a pepsin fragment of laminin (P-lam) contain distinct sites for HT-1080 human fibrosarcoma cell attachment and for neurite outgrowth activity of PC12 and NG108-15 cell lines. Reduction and alkylation of laminin and P-lam fragment disulfide bonds, in the absence of denaturing agents, markedly reduced the cell attachment activity without reducing the neurite outgrowth response. The P-lam fragment (approximately 375 kDa) was found to contain part of the cross region of laminin and a portion of the long arm, on the basis of recognition by antisera against laminin synthetic peptides and fusion proteins. Modification of arginine residues by cyclohexanedione also had no effect on neurite outgrowth but reduced HT-1080 cell adhesion. Modification of lysine residues by succinic and citraconic anhydride, however, abolished laminin neurite outgrowth but not cell attachment activity. Neurite outgrowth activity was recovered by reversing the lysine modification. These data support the existence on laminin of separate sites for cell attachment and for neurite outgrowth.
Research Interests: Developmental Biology, Cell Adhesion, Western blotting, Biological Sciences, Heparin, and 13 moreAnimals, Neurons, Rats, Protein Conformation, Alkylation, Molecular weight, Structure activity Relationship, Biological Assay, Oxidation-Reduction, Laminin, binding sites, Medical and Health Sciences, and In Vitro Techniques
Neurons from peripheral and central nervous tissue as well as from established cell lines respond to low concentrations of laminin with rapid extension of axon-like processes. Two sites on laminin have been identified which stimulate... more
Neurons from peripheral and central nervous tissue as well as from established cell lines respond to low concentrations of laminin with rapid extension of axon-like processes. Two sites on laminin have been identified which stimulate neurite outgrowth, the major site residing at the end of the long arm of laminin. Recently laminin has been cloned and sequenced allowing for synthetic peptides to be prepared and tested for biological activity. We report here that antisera against synthetic peptides corresponding to A and to B1 chain sequences at the end of the long arm can partially inhibit laminin-mediated neurite outgrowth. Further, we show that a 19 amino acid synthetic peptide (CSRARKQAASIKVAVSADR) from the long arm of the laminin A chain is capable of stimulating neuronal-like process formation to almost the same extent as laminin and competes with laminin for stimulation of neurite outgrowth.