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H K Kleinman

Publications and source records attributed to H K Kleinman.

At least 127 records · Page 7Linked to original sources
PubMed1993

110/140 laminin-binding protein immunoreactivity in spinal dorsal root ganglia: a capsaicin-insensitive reduction induced by constriction injury of the sciatic nerve in rats.

The distribution of 110/140 laminin-binding protein (110/140 LBP) in the spinal dorsal root ganglia (DRG) and its regulation by partial constriction of the sciatic nerve was studied in adult rats. The cross-sectional area of neurons with 110/140 LBP-immunoreactivity (-I) showed an approximately normal frequency distribution. The 110/140 LBP-I was observed in neuronal cell bodies exclusive of the nucleus. Following sciatic nerve constriction, the 110/140 LBP-I was downregulated in the ipsilateral L4-5 DRG. DRG neurons with a cross-sectional area > or = 1600 microns 2 were preferentially affected. Neonatal capsaicin-treatment, a procedure that selectively destroys a subpopulation of DRG neurons with fine unmyelinated axons, had no effect on the reduction of 110/140 LBP in the DRG induced by sciatic nerve constriction. Western immunoblot analysis confirmed a reduction of 110/140 LBP on the side ipsilateral to the constriction. These results demonstrate a LBP within primary sensory neurons and its suppression by peripheral nerve injury. The data support a role for LBP in the adult nervous system.

Animals↗
PubMed1993

Identification of a novel cell attachment domain in the HIV-1 Tat protein and its 90-kDa cell surface binding protein.

The HIV-1 transactivator protein Tat is essential for viral gene expression and replication. Tat is taken up by cells and transactivates the HIV-LTR promoter in the cell nucleus. The present studies show that cells adhere to both synthetic and recombinant Tat, and, using synthetic peptides, we localize the binding site to a region spanning amino acid residues 49-57 (peptide Tat49-57). Tat49-57 also inhibited cell attachment to solid phase full-length Tat peptide and to recombinant Tat protein. Using Tat peptide affinity chromatography, we identified a 90-kDa cell surface protein that binds to Tat. The 90-kDa protein could be eluted from the Tat column using the Tat49-57 peptide. A 90-kDa cell surface Tat binding protein was also identified by coprecipitation with Tat after incubation with radiolabeled cell membrane preparations. Co-precipitation of the 90-kDa protein was inhibited by competition with a Tat49-65 peptide, but not with Tat55-86. Our findings suggest that cellular attachment to Tat is mediated through a 90-kDa cell surface protein that binds to a Tat domain between amino acids 49 and 57.

Amino Acid Sequence↗
PubMed1993

Scatter factor induces blood vessel formation in vivo.

Scatter factor (also known as hepatocyte growth factor) is a glycoprotein secreted by stromal cells that stimulates cell motility and proliferation. In vitro, scatter factor stimulates vascular endothelial cell migration, proliferation, and organization into capillary-like tubes. Using two different in vivo assays, we showed that physiologic quantities of purified native mouse scatter factor and recombinant human hepatocyte growth factor induce angiogenesis (the formation of new blood vessels). The angiogenic activity was blocked by specific anti-scatter factor antibodies. Scatter factor induced cultured microvascular endothelial cells to accumulate and secrete significantly increased quantities of urokinase, an enzyme associated with development of an invasive endothelial phenotype during angiogenesis. We further showed that immunoreactive scatter factor is present surrounding sites of blood vessel formation in psoriatic skin. These findings suggest that scatter factor may act as a paracrine mediator in pathologic angiogenesis associated with human inflammatory disease.

Animals↗
PubMed1993

Melanoma cells selected for adhesion to laminin peptides have different malignant properties.

Laminin is an important promoter of cell-matrix interactions. A number of active laminin domains have been defined by use of synthetic peptides. The Tyr-Ile-Gly-Ser-Arg (YIGSR) sequence on the B1 chain in laminin can decrease tumor growth and metastasis, whereas another sequence containing Ser-Ile-Lys-Val-Ala-Val (SIKVAV) on the A chain can increase tumor growth and metastasis. Here, we selected B16-F10 melanoma cells by adherence or nonadherence to either YIGSR- or SIKVAV-coated dishes and established 3 B16-F10 variants: YIGSR-adherent cells (Y+), YIGSR-nonadherent cells (Y-), and SIKVAV-nonadherent cells (S-). SIKVAV-adherent cells were not selected because most of F10 cells attached to the SIKVAV-coated dish. These cell lines proliferated at the same rate as the parent F10 cells and attached equally to laminin, collagen IV, and fibronectin. Y+ cells produced rapidly growing tumors after s.c. injection and twice as many lung colonies as the parental F10 cells after i.v. injection. In contrast, Y- cells produced more slowly growing tumors after s.c. injection and produced one-third of the lung colonies relative to the parent cells after i.v. injection. S- cells produced slowly growing tumors after s.c. injection and yielded similar numbers but smaller colonies in the lung than the parental B16-F10 cells after i.v. injection. These data suggest that interactions of melanoma cells with the YIGSR site on laminin are probably important for both colony formation in a target organ (lung) and subsequent tumor growth, while the SIKVAV-containing site on laminin may be more important for tumor growth.

Amino Acid Sequence↗
PubMed1993

Human T lymphocytes synthesize the 92 kDa type IV collagenase (gelatinase B).

In order for T cells to exit the circulatory system, traverse the endothelial basement membrane, and arrive in target tissues, these cells must attach to and degrade basement membrane proteins. 12-O-tetradecanoylphorbol-13-acetate (TPA) has been shown to stimulate lymphoid cell adhesion to basement membrane components. We have used TPA to study the ability of human lymphoid cells to secrete type IV collagenases, enzymes capable of degrading basement membrane proteins. Here, we found that human primary T cells and H-9 lymphoid cells synthesize the 92 kDa type IV collagenase (gelatinase B) and TPA stimulates the synthesis and secretion of this protease. Peak TPA-stimulated gelatinase B secretion and mRNA accumulation were observed 9 hours after TPA treatment, while the peak adhesion to type IV collagen was observed only 3 hours after TPA treatment. The protein kinase C inhibitor, H-7, inhibited TPA-stimulated gelatinase B secretion. Both the primary T cells and H-9 lymphoid cells also expressed the mRNA for the tissue inhibitor of metalloproteinase-1 (TIMP-1). These data demonstrate that TPA-stimulated lymphoid cells adhere to type IV collagen and subsequently synthesize and secrete gelatinase B and TIMP-1. We conclude that lymphoid cell extravasation may involve cellular employment of adhesion mechanisms prior to degradation of the matrix, which is similar to the process of extravasation used by metastatic cells.

Animals↗
PubMed1993

Regulation of cell function by extracellular matrix.

The extracellular matrix (ECM) provides structural support and adhesive substrates for the body tissues. Recent advances in our understanding of the biology of matrix indicate that the ECM also plays a significant role in regulating the behavior of cells. Matrix proteins engender changes in cell shape and movement, bind growth factors, and facilitate cell-cell and cell-matrix interactions. Matrix-induced differentiation results from multiple stimuli that include: tensile forces on the cell, cytokine- or growth factor-mediated stimulation, and interaction with bioactive domains of matrix glycoproteins. Because these signals are important determinants of cell behavior, pharmacological manipulation of cell-matrix interactions may offer a valuable new approach to disease treatment.

Animals↗
PubMed1993

Localization of a laminin-binding protein in brain.

A 110,000 mol.wt laminin-binding protein from newborn mouse brain recognizes a neurite promoting laminin A chain site and is related to the beta-amyloid precursor protein. In the present study, we examined the expression of 110,000 mol.wt laminin-binding protein in brains of adult mice, rats, and non-human primates. Essentially identical immunoreactivities were observed across species with distinct staining of cortical pyramidal neurons with apical dendrites, cerebellar basket cell axons, hippocampal mossy fibers, and fine labeling of processes throughout the brain. Colocalization of immunoreactivities to 110,000 mol.wt laminin-binding protein and to laminin in neurons of the adult rat brain was observed. Electron microscopy demonstrated that 110,000 mol.wt laminin-binding protein-like immunoreactivity is intracellular and is possibly associated with the neuronal cytoskeleton. Western blot analysis revealed that anti-110,000 mol.wt laminin-binding protein also recognizes a 140,000 mol.wt protein in the pellet, in addition to the 110,000 mol.wt protein in the Triton soluble extract. Antibody fractions specific to the two reactive protein species (110,000 mol.wt and 140,000 mol.wt) exhibited cross-reactivity on immunoblots and revealed similar immunohistochemical staining in adult brain. Results suggest a significant interaction between laminin-like molecules and 110,000 mol.wt laminin-binding protein-like molecules in normal brain function, in response to CNS injury and possibly in the pathogenesis of Alzheimer's disease.

Amino Acid Sequence↗
PubMed1993

The laminins: a family of basement membrane glycoproteins important in cell differentiation and tumor metastases.

Laminins are a family of basement membrane-derived glycoproteins that are very biologically active with a number of diverse cell types. The response of the cells is dependent on the cell type and various cell-specific intracellular events are activated. Multiple active sites on laminin and cellular receptors have been described. Both laminin and the synthetic peptides that define the active sites may have important clinical uses. For example, the neurite-promoting peptides may be useful in vivo in regeneration studies because of their potent activity with neural cells and their lack of antigenicity. Also, peptides, such as YIGSR, that inhibit angiogenesis are potentially useful for treating the vascularization of the eye that occurs in conditions such as diabetes mellitus. Likewise, the angiogenic peptide SIKVAV, because of its role in endothelial cell block vessel formation, may be useful for treating ischemia. The recent progress that has been made in characterizing basic mechanisms of action of laminin has laid the groundwork for more direct studies of its clinical relevance.

Amino Acid Sequence↗
PubMed1993

Role of laminin in endothelial cell recognition and differentiation.

The vascular endothelium normally is maintained in a quiescent state, but under certain conditions it is induced to undergo marked changes in behavior and form new vascular structures. A complex interaction among various growth and differentiation factors and the extracellular milieu regulates this behavior. One series of signals affecting endothelial behavior is provided by laminin, a major structural protein of basement membrane. These signals have been studied using Matrigel, a reconstituted basement membrane preparation from the murine Englebreth-Holm-Swarm sarcoma, in an in vitro assay of endothelial cell differentiation. Three biologically-active sequences from the laminin molecule have been evaluated. Synthetic peptides that include the sequences -RGD-, -YIGSR-, and -SIKVAV- mediate, respectively, cell binding to Matrigel, alterations in cell morphology, and induction of migration and collagenase activity. Preliminary data indicate that observations made with this system may be relevant to endothelial function in vivo. Endothelial cell differentiation on Matrigel may thus be a useful in vitro model for the study of certain steps in angiogenesis.

Amino Acid Sequence↗
PubMed1993

HIV-1 infection stimulates T cell invasiveness and synthesis of the 92-kDa type IV collagenase.

Tissue-specific localization of HIV-1-infected lymphoid cells may contribute to clinical manifestations of AIDS. Therefore we investigated the effect of HIV-1 infection on mechanisms of T lymphocyte invasion, a process required for movement of cells into and out of the circulation. In the present study, we demonstrate that HIV-1-infected human lymphocytes secrete increased amounts of the human 92-kDa type IV collagenase when compared to uninfected lymphocytes. Furthermore, HIV-1-infected lymphocytes degrade the extracellular matrix proteins collagen IV and fibronectin, and they are more invasive through a reconstituted basement membrane when compared to uninfected cells. The addition of either antibody to the 92-kDa collagenase or TIMP-2, a type IV collagenase inhibitor, abolishes invasive activity. These data suggest that HIV-1-infected lymphocytes express phenotypic characteristics that are consistent with an enhanced ability to leave the circulation and to localize in target tissues. Local viral infection or the release of viral proteins, cytokines, or proteolytic enzymes in tissues may contribute to pathogenesis.

Cell Movement↗
PubMed1993

Human neoplastic submandibular intercalated duct cells express an acinar phenotype when cultured on a basement membrane matrix.

Culture of the human neoplastic submandibular gland intercalated duct cell line, HSG, on the basement membrane extract Matrigel induces dramatic morphologic changes and cytodifferentiation. Transmission electron microscopy demonstrated an acinar cell phenotype with polarized cells containing a well-developed Golgi apparatus, multiple microvilli-like projections from the apical surfaces into a lumenal-like area, and numerous granule-like organelles. Amylase, an acinar cell marker, was detected by both immunocytochemical and Northern blot analyses. A 50% reduction in [3H]thymidine incorporation by cells cultured on Matrigel, as compared to cells cultured on tissue culture plates, confirmed the differentiated phenotype of the cells. Multiple components of Matrigel appear to contribute to the morphologic differentiation of the HSG cells since antibodies to both laminin and collagen IV, as well as the laminin-derived bioactive peptide containing SIKVAV, have potent inhibitory effects on HSG cell organization on Matrigel. Collectively, these data indicate that culture of HSG cells on Matrigel is a useful model to study salivary gland acinar development.

Amylases↗
PubMed1993

Identification of haptoglobin as an angiogenic factor in sera from patients with systemic vasculitis.

Angiogenesis is an important process in chronic inflammatory diseases. We observed that sera from patients with systemic vasculitis stimulated angiogenesis in an in vitro model using human umbilical vein endothelial cells cultured on a basement membrane (Matrigel) substrate. After 40% ammonium sulfate precipitation, angiogenic activity remained in the low molecular weight fraction and could be inactivated by heat. SDS-page of serum FPLC fractions exhibiting maximal angiogenic activity demonstrated two prominent species of 45 and 16-20 kD in patients' sera. These bands were much less apparent in sera obtained from control subjects. Amino-terminal sequencing of the 45-kD protein demonstrated that it was haptoglobin. Purified haptoglobin stimulated angiogenesis in a dose-dependent manner. The angiogenic activity of vasculitis patients' sera was partially inhibited by an antihaptoglobin antibody. Furthermore, serum haptoglobin levels in vasculitis patients correlated both with disease and angiogenic activity. Haptoglobin angiogenic activity was confirmed in two in vivo models using an implanted disc and a subcutaneous injection of basement membrane. Stimulation of angiogenesis is a newly recognized biological function of haptoglobin. The increased levels of haptoglobin found in chronic inflammatory conditions may play an important role in tissue repair. In systemic vasculitis, haptoglobin might also compensate for ischemia by promoting development of collateral vessels.

Amino Acid Sequence↗
PubMed1993

Scatter factor (hepatocyte growth factor) is a potent angiogenesis factor in vivo.

Scatter factor (SF), a fibroblast-derived cytokine characterized by its ability to convert non-motile epithelial cells to a motile fibroblast-like phenotype, is identical to hepatocyte growth factor (HGF), a broad-spectrum mitogen. SF is a heterodimeric glycoprotein that is homologous to plasminogen and other blood coagulation proteases but lacks proteolytic activity. Its receptor is the c-met proto-oncogene product, a growth factor receptor-like transmembrane tyrosine kinase. This unique cytokine is also synthesized and secreted by vascular smooth muscle cells and acts on endothelial cells to stimulate migration, protease production, invasion, proliferation, and differentiation into capillary-like tubes in vitro. SF-containing implants in mouse subcutaneous tissue and rat cornea induce directed ingrowth of new blood vessels from surrounding tissue, with maximal angiogenic responses at doses of 100-200 ng of SF. Immunoreactive SF is expressed at sites of neovascularization within human psoriatic plaques. These findings suggest that SF may play a significant role in the formation and repair of blood vessels under physiologic and pathologic conditions.

Angiogenesis Inducing Agents↗
PubMed1993

Effect of Matrigel and laminin peptide YIGSR on tumor growth and metastasis.

Basement membrane has a variety of effects on tumor cells and promotes malignant behavior. Tumor cell growth is enhanced both in vitro and in vivo in mice in the presence of basement membrane. This has led to the ability to grow various tumors including human biopsy specimens in nude mice. Furthermore, low cell numbers can be used when coinjected with Matrigel, a basement membrane extract. The basement membrane glycoprotein laminin is important in promoting invasive behavior and the level of a 32/67 kDa laminin receptor has been shown to correlate with malignancy. A sequence of five amino acids, tyrosine-isoleucine-glycine-serine-arginine (YIGSR) has been shown to recognize this receptor and to reduce experimental metastases (tail vein injection resulting in colonization of the lung) and subcutaneous tumor growth. This peptide is active in both models either when coinjected or when daily intraperitoneal injections are given after tumor growth has initiated. YIGSR does not effect cell arrest but does inhibit angiogenesis which is necessary for tumor growth. YIGSR also appears to have an additional antitumor effect via its interaction with a specific receptor. YIGSR-adherent cells established after 30 successive selections on YIGSR-coated dishes in vitro formed more lung colonies after intravenous injection and larger tumors after subcutaneous injection than the parent B16F10 melanoma cells. The YIGSR-non-adherent cells formed fewer lung colonies and smaller subcutaneous tumors. These data demonstrate the importance of laminin-tumor cell interactions in malignancies and suggest that a short sequence from laminin has multiple effects in reducing tumor growth and spread.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1992

Role of the SIKVAV site of laminin in promotion of angiogenesis and tumor growth: an in vivo Matrigel model.

BACKGROUND: Angiogenesis (vascularization) has a critical role in tumor growth and metastasis, and peptides containing the SIKVAV amino acid sequence (Ser-Ile-Lys-Val-Ala-Val) have been shown to stimulate many angiogenic activities in vitro. The use of model systems to identify agents that stimulate or inhibit angiogenesis may lead to the development of new antitumor strategies. PURPOSE: Our purpose was to use an in vivo murine model system to study the angiogenic activity of a synthetic peptide derived from the laminin A protein chain and containing the SIKVAV amino acid sequence. We also examined the ability of the peptide to enhance tumor growth in vivo. METHODS: The SIKVAV-containing peptide was mixed with Matrigel, a reconstituted basement membrane extract used to assay stimulation of angiogenesis. The mixture was subcutaneously injected into C57BL/6 mice. At various times after injection, the Matrigel plug was excised, and angiogenic activity was assessed by histologic examination and immunohistochemical staining with an antibody to the von Willebrand factor (vWF), an endothelium-specific antigen. In other experiments, the mixture of peptide and Matrigel was co-injected with B16F10 murine melanoma cells into C57BL/6 mice, and the resultant tumors were assessed for size and vascularization. RESULTS: When co-injected with Matrigel at doses as low as 10 micrograms, the SIKVAV-containing peptide stimulated angiogenesis fourfold greater than that seen in controls, and maximum angiogenic activity was observed 2 weeks after injection. This peptide was angiogenic in a dose-dependent manner up to a 100-micrograms dose. When co-injected with Matrigel and B16F10 melanoma cells, the peptide enhanced tumor growth by approximately 2.5-fold, and tumor vascularization was significantly increased (P = .027) over that observed after injection with melanoma cells and Matrigel alone. CONCLUSIONS: These data demonstrate that the laminin-derived SIKVAV-containing peptide is angiogenic in a new in vivo model system and can enhance tumor vascularization and growth.

Amino Acid Sequence↗
PubMed1992

Adenovirus-mediated transfer of a recombinant human alpha 1-antitrypsin cDNA to human endothelial cells.

To evaluate the feasibility of using a replication-deficient recombinant adenovirus to transfer human genes to the human endothelium, human umbilical vein endothelial cells were infected in vitro with adenovirus vectors containing the lacZ gene or a human alpha 1-antitrypsin (alpha 1AT) cDNA. After in vitro infection with the lacZ adenovirus vector, cultured endothelial cells expressed beta-galactosidase. In parallel studies with the alpha 1AT adenovirus vector, infected cells expressed human alpha 1AT transcripts, as evidenced by in situ hybridization and Northern analysis, and de novo synthesized and secreted glycosylated, functional alpha 1AT within 6 hr of infection, as shown by [35S]methionine labeling and immunoprecipitation. Quantification of the culture supernatants demonstrated 0.3-0.6 micrograms of human alpha 1AT secreted per 10(6) cells in 24 hr, for at least 14 days after adenovirus vector infection. To demonstrate the feasibility of direct transfer of genes into endothelial cells in human blood vessels, lacZ or alpha 1AT adenovirus vectors were placed in the lumen of intact human umbilical veins ex vivo. Histologic evaluation of the veins after 24 hr demonstrated transfer and expression of the lacZ gene specifically to the endothelium. alpha 1AT adenovirus infection resulted both in expression of alpha 1AT transcripts in the endothelium and in de novo synthesis and secretion of alpha 1AT. Quantification of alpha 1AT in the vein perfusates showed average levels of 13 micrograms/ml after 24 hr. These observations strongly support the feasibility of in vivo human gene transfer to the endothelium mediated by replication-deficient adenovirus vectors.

Adenoviruses, Human↗