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Sample records for growth factor heparin

  1. Synthetic heparin-binding growth factor analogs

    DOEpatents

    Pena, Louis A.; Zamora, Paul; Lin, Xinhua; Glass, John D.

    2007-01-23

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain that binds a heparin-binding growth factor receptor, covalently bound to a hydrophobic linker, which is in turn covalently bound to a non-signaling peptide that includes a heparin-binding domain. The synthetic heparin-binding growth factor analogs are useful as soluble biologics or as surface coatings for medical devices.

  2. Dual chain synthetic heparin-binding growth factor analogs

    DOEpatents

    Zamora, Paul O.; Pena, Louis A.; Lin, Xinhua

    2012-04-24

    The invention provides synthetic heparin-binding growth factor analogs having two peptide chains each branched from a branch moiety, such as trifunctional amino acid residues, the branch moieties separated by a first linker of from 3 to about 20 backbone atoms, which peptide chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a second linker, which may be a hydrophobic second linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  3. Dual chain synthetic heparin-binding growth factor analogs

    DOEpatents

    Zamora, Paul O.; Pena, Louis A.; Lin, Xinhua

    2009-10-06

    The invention provides synthetic heparin-binding growth factor analogs having two peptide chains each branched from a branch moiety, such as trifunctional amino acid residues, the branch moieties separated by a first linker of from 3 to about 20 backbone atoms, which peptide chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a second linker, which may be a hydrophobic second linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  4. Polyelectrolyte Complex for Heparin Binding Domain Osteogenic Growth Factor Delivery.

    PubMed

    Wing Moon Lam, Raymond; Abbah, Sunny Akogwu; Ming, Wang; Naidu, Mathanapriya; Ng, Felly; Tao, Hu; Goh Cho Hong, James; Ting, Kang; Hee Kit, Wong

    2016-01-01

    During reconstructive bone surgeries, supraphysiological amounts of growth factors are empirically loaded onto scaffolds to promote successful bone fusion. Large doses of highly potent biological agents are required due to growth factor instability as a result of rapid enzymatic degradation as well as carrier inefficiencies in localizing sufficient amounts of growth factor at implant sites. Hence, strategies that prolong the stability of growth factors such as BMP-2/NELL-1, and control their release could actually lower their efficacious dose and thus reduce the need for larger doses during future bone regeneration surgeries. This in turn will reduce side effects and growth factor costs. Self-assembled PECs have been fabricated to provide better control of BMP-2/NELL-1 delivery via heparin binding and further potentiate growth factor bioactivity by enhancing in vivo stability. Here we illustrate the simplicity of PEC fabrication which aids in the delivery of a variety of growth factors during reconstructive bone surgeries. PMID:27585207

  5. Growth factors with heparin binding affinity in human synovial fluid

    SciTech Connect

    Hamerman, D.; Taylor, S.; Kirschenbaum, I.; Klagsbrun, M.; Raines, E.W.; Ross, R.; Thomas, K.A.

    1987-12-01

    Synovial effusions were obtained from the knees of 15 subjects with joint trauma, menisceal or ligamentous injury, or osteoarthritis. Heparin-Sepharose affinity chromatography of these synovial fluids revealed, in general, three major peaks of mitogenic activity as measured by incorporation of /sup 3/H-thymidine into 3T3 cells. Gradient elution patterns showed activities at 0.5M NaCl, which is characteristic of platelet derived growth factor, and at 1.1 M NaCl and 1.6M NaCl, indicative of acidic and basic fibroblast growth factors, respectively. The identities of these mitogenic fractions were confirmed by specific immunologic and receptor-binding assays. The presence of platelet derived, acidic and basic fibroblast growth factors in the synovial fluid may contribute to wound healing in the arthritic joint.

  6. Heparin Affinity: Purification of a Tumor-Derived Capillary Endothelial Cell Growth Factor

    NASA Astrophysics Data System (ADS)

    Shing, Y.; Folkman, J.; Sullivan, R.; Butterfield, C.; Murray, J.; Klagsbrun, M.

    1984-03-01

    A tumor-derived growth factor that stimulates the proliferation of capillary endothelial cells has a very strong affinity for heparin. This heparin affinity makes it possible to purify the growth factor to a single-band preparation in a rapid two-step procedure. The purified growth factor is a cationic polypeptide, has a molecular weight of about 18,000, and stimulates capillary endothelial cell proliferation at a concentration of about 1 nanogram per milliliter.

  7. Effects of class I heparin binding growth factor and fibronectin on platelet adhesion and aggregation

    SciTech Connect

    Greisler, H.P.; Klosak, J.J.; Steinam, S.J.; Lam, T.M.; Burgess, W.H.; Kim, D.U. )

    1990-05-01

    Fibronectin and heparin binding growth factor-type 1 have been affixed to vascular graft surfaces to enhance the attachment and the proliferation of transplanted endothelial cells, respectively. The current study examines the effect of fibronectin and heparin binding growth factor-type 1 on platelet adhesion and activation in vivo and on platelet aggregation in vitro. Expanded polytetrafluoroethylene prostheses (5 cm x 4 mm internal diameter) were treated either with fibronectin (n = 9), fibronectin/heparin/heparin binding growth factor-type 1/heparin (n = 12), or neither (n = 13) and were interposed into canine aortoiliac systems bilaterally. Autogenous radiolabeled (Indium 111 oxine, 650 microCi) platelets were injected intravenously before reestablishment of circulation. Perfusion was maintained for 30 minutes, and prostheses were removed with segments of native aorta and distal iliac arteries bilaterally. Specimens were examined for thrombus-free surface area, by gamma well counting for adherent radiolabeled platelets, and by light microscopy and transmission and scanning electron microscopic techniques. Results showed that both the fibronectin and fibronectin/heparin/heparin binding growth factor-type 1/heparin pretreated prostheses contained significantly greater numbers of platelets and adherent radioactivity than did control graft segments when normalized to their ipsilateral iliac arteries. Fibronectin/heparin/heparin binding growth factor-type 1/heparin pretreated prostheses contained 27 +/- 16 times more radioactivity per square millimeter than ipsilateral iliac arteries, fibronectin pretreated prostheses had 13 +/- 8 times more radioactivity per square millimeter than ipsilateral iliac arteries, and untreated expanded polytetrafluoroethylene had 4 +/- 3 times more radioactivity per square millimeter than ipsilateral iliac arteries.

  8. The activation of fibroblast growth factors by heparin: synthesis, structure, and biological activity of heparin-like oligosaccharides.

    PubMed

    de Paz, J L; Angulo, J; Lassaletta, J M; Nieto, P M; Redondo-Horcajo, M; Lozano, R M; Giménez-Gallego, G; Martín-Lomas, M

    2001-09-01

    An effective strategy has been designed for the synthesis of oligosaccharides of different sizes structurally related to the regular region of heparin; this is illustrated by the preparation of hexasaccharide 1 and octasaccharide 2. This synthetic strategy provides the oligosaccharide sequence containing a D-glucosamine unit at the nonreducing end that is not available either by enzymatic or chemical degradation of heparin. It may permit, after slight modifications, the preparation of oligosaccharide fragments with different charge distribution as well. NMR spectroscopy and molecular dynamics simulations have shown that the overall structure of 1 in solution is a stable right-hand helix with four residues per turn. Hexasaccharide 1 and, most likely, octasaccharide 2 are, therefore, chemically well-defined structural models of naturally occurring heparin-like oligosaccharides for use in binding and biological activity studies. Both compounds 1 and 2 induce the mitogenic activity of acid fibroblast growth factor (FGF1), with the half-maximum activating concentration of 2 being equivalent to that of heparin. Sedimentation equilibrium analysis with compound 2 suggests that heparin-induced FGF1 dimerization is not an absolute requirement for biological activity. PMID:11828504

  9. Binding of the growth factor glycyl-L-histidyl-L-lysine by heparin.

    PubMed

    Rabenstein, D L; Robert, J M; Hari, S

    1995-12-01

    Evidence is presented that the growth factor glycyl-histidyl-lysine (GHK) binds to heparin, and the interaction has been characterized by [1H]NMR spectroscopy. 1H chemical shifts indicate that GHK interacts with both the carboxylic acid and the carboxylate forms of heparin. The chemical shift data are consistent with a weak delocalized binding of the triprotonated (ImH+, GlyNH3+, LysNH3+) form of GHK by the carboxylic acid form of heparin. As the pD is increased and the carboxylic acid groups are titrated, chemical shift data indicate that ammonium groups of GHK are hydrogen bonded to heparin carboxylate groups, while the histidyl imidazolium ring occupies the imidazolium-binding site of heparin. Evidence for site-specific binding includes displacement of chemical shift titration curves for heparin to lower pD, increased shielding of specific heparin protons by the imidazolium ring current and displacement of chemical shift titration curves for GHK to higher pD. Specific binding constants were determined for binding of the (ImH+, GlyNH3+), LysNH3+) forms of GHK by the carboxylate form of heparin from chemical shift vs. pD titration data. PMID:7498545

  10. Pharmacokinetics and distribution of heparin-binding growth factor I (endothelial cell growth factor) in the rat

    SciTech Connect

    Rosengart, T.K.; Kuperschmid, J.P.; Maciag, T.; Clark, R.E.

    1989-02-01

    Heparin-binding growth factor I (HBGF I), previously designated as endothelial cell growth factor, is a potent mitogen for endothelial cells in vitro, which may prove useful for promoting endothelial regeneration in vivo. Analysis of the pharmacokinetics and organ distribution of HBGF I is necessary before use of HBGF I as a pharmacological agent. Consequently, pharmacological studies were carried out with (125I)HBGF I in the rat. Intravenous injections of HBGF I were given with or without heparin (2.5 units/ng HBGF I). Blood concentrations of HBGF I decreased by one half 17 seconds after HBGF I bolus. This time was prolonged to 60 seconds when HBGF I was injected with heparin. The elimination half-life of HBGF I was 14 minutes in the presence of heparin. The highest concentrations of HBGF I following intravenous bolus were found in kidney, liver, and spleen, and the lowest in fat and brain. Heparin increased HBGF I concentrations in blood and all organs measured except kidney, which was significantly decreased (p less than 0.01). Intact HBGF I was recoverable from blood 5 minutes following intravenous administration. HBGF I underwent near-complete proteolytic digestion after more prolonged ex vivo incubation with rat plasma, but HBGF I was protected from proteolysis when incubations were conducted in the presence of heparin. Thus, it is feasible that HBGF I can be administered as a pharmacological agent in the presence of heparin. Further studies assessing acceleration of in vivo endothelial growth using HBGF I with heparin appear warranted.

  11. Heparin Binds Endothelial Cell Growth Factor, the Principal Endothelial Cell Mitogen in Bovine Brain

    NASA Astrophysics Data System (ADS)

    Maciag, Thomas; Mehlman, Tevie; Friesel, Robert; Schreiber, Alain B.

    1984-08-01

    Endothelial cell growth factor (ECGF), an anionic polypeptide mitogen, binds to immobilized heparin. The interaction between the acidic polypeptide and the anionic carbohydrate suggests a mechanism that is independent of ion exchange. Monoclonal antibodies to purified bovine ECGF inhibited the biological activity of ECGF in crude preparations of bovine brain. These data indicate that ECGF is the principal mitogen for endothelial cells from bovine brain, that heparin affinity chromatography may be used to purify and concentrate ECGF, and that the affinity of ECGF for heparin may have structural and perhaps biological significance.

  12. Energetic characterization of the basic fibroblast growth factor-heparin interaction: identification of the heparin binding domain.

    PubMed

    Thompson, L D; Pantoliano, M W; Springer, B A

    1994-04-01

    Fibroblast growth factors (FGF's) interact on cell surfaces with "low-affinity" heparan sulfate proteoglycans (HSPG) and "high-affinity" FGF receptors (FGFR) to initiate cell proliferation. Previous reports have implicated the binding of heparin, or heparan sulfate, to FGF as essential for FGF-mediated signal transduction and mitogenicity. However, the molecular recognition events which dictate the specificity of this interaction have remained elusive. Amino acid residues on the surface of basic FGF (bFGF) were targeted as potential heparin contacts on the basis of the position of sulfate anions in the X-ray crystal structure of bFGF and of a modeled pentasaccharide heparin-bFGF complex. Each identified amino acid was replaced individually with alanine by site-directed mutagenesis, and the resulting mutant proteins were characterized for differences in binding to a low molecular weight heparin (approximately 3000) by isothermal titrating calorimetry and also for differences in [NaCl] elution from a heparin-Sepharose affinity resin. The combination of site-directed mutagenesis and titrating calorimetry permitted an analysis of the energetic contributions of individual bFGF residues in the binding of heparin to bFGF. The key amino acids which comprise the heparin binding domain on bFGF constitute a discontinuous binding epitope and include K26, N27, R81, K119, R120, T121, Q123, K125, K129, Q134, and K135. Addition of the observed delta delta G degrees of binding for each single site mutant accounts for 8.56 kcal/mol (> 95%) of the free energy of binding. The delta delta G degrees values for N27A, R120A, K125A, and Q134A are all greater than 1 kcal/mol each, and these four amino acids together contribute 4.8 kcal/mol (56%) to the total binding free energy. Amino acid residues K119 through K135 reside in the C-terminal domain of bFGF and collectively contribute 6.6 kcal/mol (76%) of the binding free energy. Although 7 out of the 11 identified amino acids in the heparin

  13. Myogenic Growth Factor Present in Skeletal Muscle is Purified by Heparin-Affinity Chromatography

    NASA Astrophysics Data System (ADS)

    Kardami, Elissavet; Spector, Dennis; Strohman, Richard C.

    1985-12-01

    A myogenic growth factor has been purified from a skeletal muscle, the anterior latissimus dorsi, of adult chickens. In the range of 1-10 ng, this factor stimulates DNA synthesis as well as protein and muscle-specific myosin accumulation in myogenic cell cultures. Purification is achieved through binding of the factor to heparin. The factor is distinct from transferrin and works synergistically with transferrin in stimulating myogenesis in vitro.

  14. Growth factors-loaded stents modified with hyaluronic acid and heparin for induction of rapid and tight re-endothelialization.

    PubMed

    Choi, Dong Hoon; Kang, Sung Nam; Kim, Seong Min; Gobaa, Samy; Park, Bang Ju; Kim, Ik Hwan; Joung, Yoon Ki; Han, Dong Keun

    2016-05-01

    Rapid re-endothelialization of damaged vessel lining efficiently prevents restenosis and thrombosis and restores original vascular functions. In this study, we designed a novel metallic stent with a heparin-modified surface and used different methods, including 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and divinyl sulfone (DVS), to load growth factors. First we loaded heparin into a dopamine-conjugated hyaluronic acid (HA) coating to serve as a growth factor reservoir. In a second step, we took advantage of the heparin-binding domain of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) to gain advanced re-endothelialization capabilities. We demonstrated that DVS technique offered higher amount of growth factor loading. In vitro assessment also showed better capillary-like structure formation and localized gap junctions when DVS coating was employed. This study suggested that growth factor loaded stent modified by HA and heparin provided the advantage to rapid and tight restoration of endothelium. PMID:26928466

  15. Epidermal growth factor loaded heparin-based hydrogel sheet for skin wound healing.

    PubMed

    Goh, MeeiChyn; Hwang, Youngmin; Tae, Giyoong

    2016-08-20

    A heparin-based hydrogel sheet composed of thiolated heparin and diacrylated poly (ethylene glycol) was prepared via photo polymerization and human epidermal growth factor (hEGF) were loaded into it for the purpose of wound healing. It showed a sustained release profile of hEGF in vitro. In order to evaluate its function on wound healing in vivo, full thickness wounds were created on the dorsal surface of mice. Application of hEGF loaded heparin-based hydrogel sheet accelerated the wound closure compared to the non-treated control group, hEGF solution, and hEGF loaded PEG hydrogel sheet. Histological and immunohistological examinations also demonstrated an advanced granulation tissue formation, capillary formation, and epithelialization in wounds treated by hEGF loaded heparin-based hydrogel compared to other groups, and no biocompatibility issue was observed. In conclusion, the delivery of hEGF using the heparin-based hydrogel could accelerate the skin wound healing process. PMID:27178931

  16. Heparin-Binding Epidermal Growth Factor-like Growth Factor/Diphtheria Toxin Receptor in Normal and Neoplastic Hematopoiesis

    PubMed Central

    Vinante, Fabrizio; Rigo, Antonella

    2013-01-01

    Heparin-binding EGF-like growth factor (HB-EGF) belongs to the EGF family of growth factors. It is biologically active either as a molecule anchored to the membrane or as a soluble form released by proteolytic cleavage of the extracellular domain. HB-EGF is involved in relevant physiological and pathological processes spanning from proliferation and apoptosis to morphogenesis. We outline here the main activities of HB-EGF in connection with normal or neoplastic differentiative or proliferative events taking place primitively in the hematopoietic microenvironment. PMID:23888518

  17. Protection of transforming growth factor-beta 1 activity by heparin and fucoidan.

    PubMed

    McCaffrey, T A; Falcone, D J; Vicente, D; Du, B; Consigli, S; Borth, W

    1994-04-01

    The transforming growth factor-beta (TGF-beta) family of proteins exert diverse and potent effects on proliferation, differentiation, and extracellular matrix synthesis. However, relatively little is known about the stability or processing of endogenous TGF-beta activity in vitro or in vivo. Our previous work indicated that 1) TGF-beta 1 has strong heparin-binding properties that were not previously recognized because of neutralization by iodination, and 2) heparin, and certain other polyanions, could block the binding of TGF-beta 1 to alpha 2-macroglobulin (alpha 2-M). The present studies investigated the influence of heparin-like molecules on the stability of the TGF-beta 1 signal in the pericellular environment. The results indicate that heparin and fucoidan, a naturally occurring sulfated L-fucose polymer, suppress the formation of an initial non-covalent interaction between 125I-TGF-beta 1 and activated alpha 2-M. Electrophoresis of 125I-TGF-beta 1 showed that fucoidan protects TGF-beta 1 from proteolytic degradation by plasmin and trypsin. While plasmin caused little, if any, activation of latent TGF-beta derived from vascular smooth muscle cells (SMC), plasmin degraded acid-activated TGF-beta, and purified TGF-beta 1, and this degradation was inhibited by fucoidan. In vitro, heparin and fucoidan tripled the half-life of 125I-TGF-beta 1 and doubled the amount of cell-associated 125I-TGF-beta 1. Consistent with this protective effect, heparin- and fucoidan-treated SMC demonstrated elevated levels of active, but not latent, TGF-beta activity. PMID:7511146

  18. Synthetic heparin-binding factor analogs

    DOEpatents

    Pena, Louis A.; Zamora, Paul O.; Lin, Xinhua; Glass, John D.

    2010-04-20

    The invention provides synthetic heparin-binding growth factor analogs having at least one peptide chain, and preferably two peptide chains branched from a dipeptide branch moiety composed of two trifunctional amino acid residues, which peptide chain or chains bind a heparin-binding growth factor receptor and are covalently bound to a non-signaling peptide that includes a heparin-binding domain, preferably by a linker, which may be a hydrophobic linker. The synthetic heparin-binding growth factor analogs are useful as pharmaceutical agents, soluble biologics or as surface coatings for medical devices.

  19. Heparin Binding Epidermal Growth Factor Like Growth Factor Heals Chronic Tympanic Membrane Perforations With Advantage Over Fibroblast Growth Factor 2 and Epidermal Growth Factor in an Animal Model

    PubMed Central

    Santa Maria, Peter Luke; Weierich, Kendall; Kim, Sungwoo; Yang, Yunzhi Peter

    2016-01-01

    Hypothesis That heparin binding epidermal growth factor like growth factor (HB-EGF) heals chronic tympanic membrane (TM) perforations at higher rates than fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF) in an animal model. Background A non-surgical treatment for chronic TM perforation would benefit those unable to access surgery or those unable to have surgery, as well as reducing the cost of tympanoplasty. Growth factor (GF) treatments have been reported in the literature with variable success with the lack of a suitable animal providing a major obstacle. Methods The GFs were tested in a validated mouse model of chronic TM perforation. A bio absorbable hydrogel polymer was used to deliver the GF at a steady concentration as it dissolved over four weeks. A control (polymer only, n=18) was compared to polymer loaded with HB-EGF (5ug/ml, n=18), FGF2 (100ug/ml, n=19) and EGF (250ug/ml, n=19). Perforations were inspected at four weeks. Results The healing rates, as defined as one hundred percent perforation closure, were control (5/18, 27.8%), HB-EGF (15/18, 83.3%), FGF2 (6/19, 31.6%) and EGF (3/19, 15.8%). There were no differences between FGF2 (p=0.80) and EGF (p=0.31) with control healing rates. HB-EGF (p= 0.000001) showed a significant difference for healing. The HB-EGF healed TMs showed layers similar to a normal TM, whilst the other groups showed a lack of epithelial migration. Conclusion This study confirms the advantage of HB-EGF over two other commonly used growth factors and is a promising non-surgical treatment of chronic TM perforations. PMID:26075672

  20. Nanoscale growth factor patterns by immobilization on a heparin-mimicking polymer.

    PubMed

    Christman, Karen L; Vázquez-Dorbatt, Vimary; Schopf, Eric; Kolodziej, Christopher M; Li, Ronald C; Broyer, Rebecca M; Chen, Yong; Maynard, Heather D

    2008-12-10

    In this study, electrostatic interactions between sulfonate groups of an immobilized polymer and the heparin binding domains of growth factors important in cell signaling were exploited to nanopattern the proteins. Poly(sodium 4-styrenesulfonate-co-poly(ethylene glycol) methacrylate) (pSS-co-pPEGMA) was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using ethyl S-thiobenzoyl-2-thiopropionate as a chain transfer agent and 2,2'-azoisobutyronitrile (AIBN) as the initiator. The resulting polymer (1) was characterized by 1H NMR, GPC, FT-IR, and UV-vis and had a number average molecular weight (Mn) of 24,000 and a polydispersity index (PDI) of 1.17. The dithioester end group of 1 was reduced to the thiol, and the polymer was subsequently immobilized on a gold substrate. Binding of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) to the polymer via the heparin binding domains was then confirmed by surface plasmon resonance (SPR). The interactions were stable at physiological salt concentrations. Polymer 1 was cross-linked onto silicon wafers using an electron beam writer forming micro- and nanopatterns. Resolutions of 100 nm and arbitrary nanoscale features such as concentric circles and contiguous squares and triangles were achieved. Fluorescence microscopy confirmed that bFGF and VEGF were subsequently immobilized to the polymer micro- and nanopatterns. PMID:19554729

  1. Keratinocyte growth factor and hepatocyte growth factor/scatter factor are heparin-binding growth factors for alveolar type II cells in fibroblast-conditioned medium.

    PubMed Central

    Panos, R J; Rubin, J S; Csaky, K G; Aaronson, S A; Mason, R J

    1993-01-01

    Epithelial-mesenchymal interactions mediate aspects of normal lung growth and development and are important in the restoration of normal alveolar architecture after lung injury. To determine if fibroblasts are a source of soluble growth factors for alveolar type II cells, we investigated the effect of fibroblast-conditioned medium (CM) on alveolar type II cell DNA synthesis. Serum-free CM from confluent adult human lung fibroblasts was concentrated fivefold by lyophilization. Type II cells were isolated from adult rats by elastase dissociation and incubated with [3H]thymidine and varying dilutions of concentrated CM and serum from day 1 to 3 of culture. Stimulation of type II cell DNA synthesis by fibroblast-CM was maximal after 48 h of conditioning and required the presence of serum. The activity of the CM was eliminated by boiling and by treatment with trypsin, pepsin, or dithiothreitol and was additive with saturating concentrations of acidic fibroblast growth factor, epidermal growth factor, and insulin. The growth factor activity bound to heparin-Sepharose and was eluted with 0.6 and 1.0 M NaCl. Neutralizing antibody studies demonstrated that the primary mitogens isolated in the 0.6 and 1.0 M NaCl fractions were keratinocyte growth factor (KGF, fibroblast growth factor 7) and hepatocyte growth factor/scatter factor (HGF/SF), respectively. HGF/SF was demonstrated in the crude CM and KGF was detected in the 0.6 M NaCl eluent by immunoblotting. Northern blot analysis confirmed that the lung fibroblasts expressed both KGF and HGF/SF transcripts. Human recombinant KGF and HGF/SF induced a concentration- and serum-dependent increase in rat alveolar type II cell DNA synthesis. We conclude that adult human lung fibroblasts produce at least two soluble heparin-binding growth factors, KGF and HGF/SF, which promote DNA synthesis and proliferation of rat alveolar type II cells in primary culture. KGF and HGF/SF may be important stimuli for alveolar type II cell

  2. A heparin-mimicking polymer conjugate stabilizes basic fibroblast growth factor

    NASA Astrophysics Data System (ADS)

    Nguyen, Thi H.; Kim, Sung-Hye; Decker, Caitlin G.; Wong, Darice Y.; Loo, Joseph A.; Maynard, Heather D.

    2013-03-01

    Basic fibroblast growth factor (bFGF) is a protein that plays a crucial role in diverse cellular functions, from wound healing to bone regeneration. However, a major obstacle to the widespread application of bFGF is its inherent instability during storage and delivery. Here, we describe the stabilization of bFGF by covalent conjugation with a heparin-mimicking polymer, a copolymer consisting of styrene sulfonate units and methyl methacrylate units bearing poly(ethylene glycol) side chains. The bFGF conjugate of this polymer retained bioactivity after synthesis and was stable to a variety of environmentally and therapeutically relevant stressors—such as heat, mild and harsh acidic conditions, storage and proteolytic degradation—unlike native bFGF. Following the application of stress, the conjugate was also significantly more active than the control conjugate system in which the styrene sulfonate units were omitted from the polymer structure. This research has important implications for the clinical use of bFGF and for the stabilization of heparin-binding growth factors in general.

  3. Basic fibroblast growth factor binds to subendothelial extracellular matrix and is released by heparitinase and heparin-like molecules

    SciTech Connect

    Bashkin, P.; Doctrow, S.; Klagsbrun, M.; Svahn, C.M.; Folkman, J.; Vlodavsky, I. )

    1989-02-21

    Basic fibroblast growth factor (bFGF) exhibits specific binding to the extracellular matrix (ECM) produced by cultured endothelial cells. Binding was saturable as a function both of time and of concentration of {sup 125}I-bFGF. Scatchard analysis of FGF binding revealed the presence of about 1.5 x 10{sup 12} binding sites/mm{sup 2} ECM with an apparent k{sub D} of 610 nM. FGF binds to heparan sulfate (HS) in ECM as evidenced by (i) inhibition of binding in the presence of heparin or HS at 0.1-1 {mu}g/mL, but not by chondroitin sulfate, keratan sulfate, or hyaluronic acid at 10 {mu}g/mL, (ii) lack of binding to ECM pretreated with heparitinase, but not with chondroitinase ABC, and (iii) rapid release of up to 90% of ECM-bound FGF by exposure to heparin, HS, or heparitinase, but not to chondroitin sulfate, keratan sulfate, hyaluronic acid, or chondroitinase ABC. Oligosaccharides derived from depolymerized heparin, and as small as the tetrasaccharide, released the ECM-bound FGF, but there was little or no release of FGF by modified nonanticoagulant heparins such as totally desulfated heparin, N-desulfated heparin, and N-acetylated heparin. FGF released from ECM was biologically active, as indicated by its stimulation of cell proliferation and DNA synthesis in vascular endothelial cells and 3T3 fibroblasts. Similar results were obtained in studies on release of endogenous FGF-like mitogenic activity from Descement's membranes of bovine corneas. It is suggested that ECM storage and release of bFGF provide a novel mechanism for regulation of capillary blood vessel growth. Whereas ECM-bound FGF may be prevented from acting on endothelial cells, its displacement by heparin-like molecules and/or HS-degrading enzymes may elicit a neovascular response.

  4. Delivering heparin-binding insulin-like growth factor 1 with self-assembling peptide hydrogels.

    PubMed

    Florine, Emily M; Miller, Rachel E; Liebesny, Paul H; Mroszczyk, Keri A; Lee, Richard T; Patwari, Parth; Grodzinsky, Alan J

    2015-02-01

    Heparin-binding insulin-like growth factor 1 (HB-IGF-1) is a fusion protein of IGF-1 with the HB domain of heparin-binding epidermal growth factor-like growth factor. A single dose of HB-IGF-1 has been shown to bind specifically to cartilage and to promote sustained upregulation of proteoglycan synthesis in cartilage explants. Achieving strong integration between native cartilage and tissue-engineered cartilage remains challenging. We hypothesize that if a growth factor delivered by the tissue engineering scaffold could stimulate enhanced matrix synthesis by both the cells within the scaffold and the adjacent native cartilage, integration could be enhanced. In this work, we investigated methods for adsorbing HB-IGF-1 to self-assembling peptide hydrogels to deliver the growth factor to encapsulated chondrocytes and cartilage explants cultured with growth factor-loaded hydrogels. We tested multiple methods for adsorbing HB-IGF-1 in self-assembling peptide hydrogels, including adsorption prior to peptide assembly, following peptide assembly, and with/without heparan sulfate (HS, a potential linker between peptide molecules and HB-IGF-1). We found that HB-IGF-1 and HS were retained in the peptide for all tested conditions. A subset of these conditions was then studied for their ability to stimulate increased matrix production by gel-encapsulated chondrocytes and by chondrocytes within adjacent native cartilage. Adsorbing HB-IGF-1 or IGF-1 prior to peptide assembly was found to stimulate increased sulfated glycosaminoglycan per DNA and hydroxyproline content of chondrocyte-seeded hydrogels compared with basal controls at day 10. Cartilage explants cultured adjacent to functionalized hydrogels had increased proteoglycan synthesis at day 10 when HB-IGF-1 was adsorbed, but not IGF-1. We conclude that delivery of HB-IGF-1 to focal defects in cartilage using self-assembling peptide hydrogels is a promising technique that could aid cartilage repair via enhanced matrix

  5. Heparin Binding–Epidermal Growth Factor-Like Growth Factor for the Regeneration of Chronic Tympanic Membrane Perforations in Mice

    PubMed Central

    Kim, Sungwoo; Varsak, Yasin Kursad; Yang, Yunzhi Peter

    2015-01-01

    We aim to explore the role of epidermal growth factor (EGF) ligand shedding in tympanic membrane wound healing and to investigate the translation of its modulation in tissue engineering of chronic tympanic membrane perforations. Chronic suppurative otitis media (CSOM) is an infected chronic tympanic membrane perforation. Up to 200 million suffer from its associated hearing loss and it is the most common cause of pediatric hearing loss in developing countries. There is a need for nonsurgical treatment due to a worldwide lack of resources. In this study, we show that EGF ligand shedding is essential for tympanic membrane healing as it's inhibition, with KB-R7785, leads to chronic perforation in 87.9% (n=58) compared with 0% (n=20) of controls. We then show that heparin binding–EGF-like growth factor (5 μg/mL), which acts to shed EGF ligands, can regenerate chronic perforations in mouse models with 92% (22 of 24) compared with 38% (10 of 26), also with eustachian tube occlusion with 94% (18 of 19) compared with 9% (2 of 23) and with CSOM 100% (16 of 16) compared with 41% (7 of 17). We also show the nonototoxicity of this treatment and its hydrogel delivery vehicle. This provides preliminary data for a clinical trial where it could be delivered by nonspecialist trained healthcare workers and fulfill the clinical need for a nonsurgical treatment for chronic tympanic membrane perforation and CSOM. PMID:25567607

  6. Molecular weight and concentration of heparin in hyaluronic acid-based matrices modulates growth factor retention kinetics and stem cell fate.

    PubMed

    Jha, Amit K; Mathur, Anurag; Svedlund, Felicia L; Ye, Jianqin; Yeghiazarians, Yerem; Healy, Kevin E

    2015-07-10

    Growth factors are critical for regulating and inducing various stem cell functions. To study the effects of growth factor delivery kinetics and presentation on stem cell fate, we developed a series of heparin-containing hyaluronic acid (HyA)-based hydrogels with various degrees of growth factor affinity and retention. To characterize this system, we investigated the effect of heparin molecular weight, fractionation, and relative concentration on the loading efficiency and retention kinetics of TGFβ1 as a model growth factor. At equal concentrations, high MW heparin both loaded and retained the greatest amount of TGFβ1, and had the slowest release kinetics, primarily due to the higher affinity with TGFβ1 compared to low MW or unfractionated heparin. Subsequently, we tested the effect of TGFβ1, presented from various heparin-containing matrices, to differentiate a versatile population of Sca-1(+)/CD45(-) cardiac progenitor cells (CPCs) into endothelial cells and form vascular-like networks in vitro. High MW heparin HyA hydrogels stimulated more robust differentiation of CPCs into endothelial cells, which formed vascular-like networks within the hydrogel. This observation was attributed to the ability of high MW heparin HyA hydrogels to sequester endogenously synthesized angiogenic factors within the matrix. These results demonstrate the importance of molecular weight, fractionation, and concentration of heparin on presentation of heparin-binding growth factors and their effect on stem cell differentiation and lineage specification. PMID:25931306

  7. Magnetic field-responsive release of transforming growth factor beta 1 from heparin-modified alginate ferrogels.

    PubMed

    Kim, Hwi; Park, Honghyun; Lee, Jae Won; Lee, Kuen Yong

    2016-10-20

    Stimuli-responsive polymeric systems have been widely used for various drug delivery and tissue engineering applications. Magnetic stimulation can be also exploited to regulate the release of pharmaceutical drugs, growth factors, and cells from hydrogels in a controlled manner, on-demand. In the present study, alginate ferrogels containing iron oxide nanoparticles were fabricated via ionic cross-linking, and their various characteristics were investigated. The deformation of the ferrogels was dependent on the polymer concentration, calcium concentration, iron oxide concentration, and strength of magnetic field. To modulate the release of transforming growth factor beta 1 (TGF-β1) under magnetic stimulation, alginate was chemically modified with heparin, as TGF-β1 has a heparin-binding domain. Alginate was first modified with ethylenediamine, and heparin was then conjugated to the ethylenediamine-modified alginate via carbodiimide chemistry. Conjugation of heparin to alginate was confirmed by infrared spectroscopy and proton nuclear magnetic resonance spectroscopy. Sustained release of TGF-β1 from alginate-g-heparin ferrogels was achieved, and application of a magnetic field to the ferrogels regulated TGF-β1 release, resultantly enhancing chondrogenic differentiation of ATDC5 cells, which were used as a model chondrogenic cell line. Alginate-based ferrogels that release drugs in a controlled manner may therefore be useful in many biomedical applications. PMID:27474590

  8. Heparinized magnetic mesoporous silica nanoparticles as multifunctional growth factor delivery carriers

    NASA Astrophysics Data System (ADS)

    Wu, Qiang; Liu, Chaoqun; Fan, Luna; Shi, Jiahua; Liu, Zhiqiang; Li, Ruifang; Sun, Liwei

    2012-12-01

    Well-defined magnetic mesoporous silica nanoparticles (MMSNs) with a core/shell structure were prepared via a one pot synthesis. Sphere-like magnetite aggregates were obtained as cores of the final nanoparticles by assembly in the presence of polyvinyl pyrrolidone and cetyltrimethylammonium bromide. The nanoparticles have the property of superparamagnetism with a saturation magnetization value of 20.3 emu g-1. In addition, the combination of heparin and fluorescence-labeled MMSNs endows the resultant particles (denoted as MFMSNs-HP) with magnetism and fluorescence properties, excellent dispersity in the buffer solutions and cell culture media, anticoagulant activity in the blood stream, and the controlled release of basic fibroblast growth factor (bFGF). Furthermore, the bFGF cell viability assays indicate that MFMSNs-HP has nearly no toxicity to human umbilical vein endothelial cells (HUVEC) up to a concentration of 200 μg ml-1, and the proliferation activity of bFGF incorporated into MFMSNs-HP could be retained for at least 6 days. All of these suggest that MFMSNs-HP may serve as a multifunctional carrier for the delivery of growth factors.

  9. Cooperative heparin-mediated oligomerization of fibroblast growth factor-1 (FGF1) precedes recruitment of FGFR2 to ternary complexes.

    PubMed

    Brown, Alan; Robinson, Christopher J; Gallagher, John T; Blundell, Tom L

    2013-04-16

    Fibroblast growth factors (FGFs) utilize cell surface heparan sulfate as a coreceptor in the assembly of signaling complexes with FGF-receptors on the plasma membrane. Here we undertake a complete thermodynamic characterization of the assembly of the FGF signaling complex using isothermal titration calorimetry. Heparin fragments of defined length are used as chemical analogs of the sulfated domains of heparan sulfate and examined for their ability to oligomerize FGF1. Binding is modeled using the McGhee-von Hippel formalism for the cooperative binding of ligands to a monodimensional lattice. Oligomerization of FGFs on heparin is shown to be mediated by positive cooperativity (α = 6). Heparin octasaccharide is the shortest length capable of dimerizing FGF1 and on longer heparin chains FGF1 binds with a minimal footprint of 4.2 saccharide units. The thermodynamics and stoichiometry of the ternary complex suggest that in solution FGF1 binds to heparin in a trans-dimeric manner before FGFR recruitment. PMID:23601319

  10. Heparin binding preference and structures in the fibroblast growth factor family parallel their evolutionary diversification

    PubMed Central

    Jiang, Chao; Wilkinson, Mark C.

    2016-01-01

    The interaction of a large number of extracellular proteins with heparan sulfate (HS) regulates their transport and effector functions, but the degree of molecular specificity underlying protein–polysaccharide binding is still debated. The 15 paracrine fibroblast growth factors (FGFs) are one of the paradigms for this interaction. Here, we measure the binding preferences of six FGFs (FGF3, FGF4, FGF6, FGF10, FGF17, FGF20) for a library of modified heparins, representing structures in HS, and model glycosaminoglycans, using differential scanning fluorimetry. This is complemented by the identification of the lysine residues in the primary and secondary binding sites of the FGFs by a selective labelling approach. Pooling these data with previous sets provides good coverage of the FGF phylogenetic tree, deduced from amino acid sequence alignment. This demonstrates that the selectivity of the FGFs for binding structures in sulfated polysaccharides and the pattern of secondary binding sites on the surface of FGFs follow the phylogenetic relationship of the FGFs, and so are likely to be the result of the natural selection pressures that led to the expansion of the FGF family in the course of the evolution of more complex animal body plans. PMID:27030175

  11. A heparin-binding growth factor secreted from breast cancer cells homologous to a developmentally regulated cytokine.

    PubMed

    Wellstein, A; Fang, W J; Khatri, A; Lu, Y; Swain, S S; Dickson, R B; Sasse, J; Riegel, A T; Lippman, M E

    1992-02-01

    We report purification of an 18-kDa heparin-binding growth factor secreted from human cancer cells which is homologous to a developmentally regulated, neurotrophic factor, heparin-binding growth-associated molecule/pleiotrophin (HB-GAM/PTN; Merenmies, J., and Rauvala, H. (1990) J. Biol. Chem. 265, 16721-16724; Li, Y. S., Milner, P. G., Chauhan, A. K., Watson, M. A., Hoffman, R. M., Kodner, C. M., Milbrandt, J., and Deuel, T. F. (1990) Science 250, 1690-1694). We have purified the protein from tissue culture supernatants of human breast cancer cells (MDA-MB 231) and have used soft agar cloning of an epithelial cell line (SW-13) to detect its growth stimulating activity. A 32,000-fold purification was achieved by isoelectric focusing, heparin affinity chromatography, and reversed phase high pressure liquid chromatography. The molecular mass of the protein was confirmed by gel filtration chromatography in the presence of detergent and bioassay of the fractions. The N-terminal sequence was homologous to HB-GAM/PTN, and polymerase chain reaction amplification and DNA sequencing confirmed that the respective transcript was present in the cancer cells. We conclude that HB-GAM/PTN can function as a tumor growth factor in addition to its role during neuronal development. PMID:1733956

  12. Heparin modulation of the neurotropic effects of acidic and basic fibroblast growth factors and nerve growth factor on PC12 cells

    SciTech Connect

    Neufeld, G.; Gospodarowicz, D.; Dodge, L.; Fujii, D.K.

    1987-04-01

    Nerve growth factor (NGF) and acidic or basic fibroblast growth factor (aFGF and bFGF, respectively) induce neurite outgrowth from the rat pheochromocytoma cell line, PC12. The neurites induced by these three factors are stable for up to a month in cell culture in the continued presence of any of the above growth factors. bFGF (ED50 = 30 pg/ml) is 800 fold more potent in stimulating neurite outgrowth than aFGF (ED50 = 25 ng/ml) and 260 fold more potent than NGF (ED50 = 8 ng/ml). While the neurotropic activities of aFGF and NGF are potentiated by heparin, that of bFGF is both partially inhibited or stimulated, depending upon the concentration of bFGF. Radioreceptor binding experiments show that aFGF and bFGF bind to a common binding site on the PC12 cell surface. Affinity labeling studies demonstrate a single receptor with an apparent molecular weight of 145,000 daltons, which corresponds to the high molecular weight receptor identified in BHK-21 cells. NGF does not appear to compete with aFGF or bFGF for binding to the receptor. Heparin blocked the binding of bFGF to the receptor but had only a small inhibitory effect on the binding of aFGF to the receptor. Thus, it appears that heparin inhibition of the neurotropic effects of bFGF occurs, at least in part, by impairing the interaction of bFGF with the receptor, while having little effect on that of aFGF. The stimulatory effects of heparin on the neurotropic activity of aFGF, bFGF, and NGF may occur through a site not associated with the respective cellular receptor for the growth factors.

  13. Angiopoietin-1 prevents severe bleeding complications induced by heparin-like drugs and fibroblast growth factor-2 in mice.

    PubMed

    Jerebtsova, Marina; Das, Jharna R; Tang, Pingtao; Wong, Edward; Ray, Patricio E

    2015-10-01

    Critically ill children can develop bleeding complications when treated with heparin-like drugs. These events are usually attributed to the anticoagulant activity of these drugs. However, previous studies showed that fibroblast growth factor-2 (FGF-2), a heparin-binding growth factor released in the circulation of these patients, could precipitate intestinal hemorrhages in mice treated with the heparin-like drug pentosan polysulfate (PPS). Yet very little is known about how FGF-2 induces bleeding complications in combination with heparin-like drugs. Here, we examined the mechanisms by which circulating FGF-2 induces intestinal hemorrhages in mice treated with PPS. We used a well-characterized mouse model of intestinal hemorrhages induced by FGF-2 plus PPS. Adult FVB/N mice were infected with adenovirus carrying Lac-Z or a secreted form of recombinant human FGF-2, and injected with PPS, at doses that do not induce bleeding complications per se. Mice treated with FGF-2 in combination with PPS developed an intestinal inflammatory reaction that increased the permeability and disrupted the integrity of submucosal intestinal vessels. These changes, together with the anticoagulant activity of PPS, induced lethal hemorrhages. Moreover, a genetically modified form of the endothelial ligand angiopoietin-1 (Ang-1*), which has powerful antipermeability and anti-inflammatory activity, prevented the lethal bleeding complications without correcting the anticoagulant status of these mice. These findings define new mechanisms through which FGF-2 and Ang-1* modulate the outcome of intestinal bleeding complications induced by PPS in mice and may have wider clinical implications for critically ill children treated with heparin-like drugs. PMID:26276817

  14. The metalloendopeptidase nardilysin (NRDc) is potently inhibited by heparin-binding epidermal growth factor-like growth factor (HB-EGF).

    PubMed Central

    Hospital, Véronique; Nishi, Eiichiro; Klagsbrun, Michael; Cohen, Paul; Seidah, Nabil G; Prat, Annik

    2002-01-01

    Nardilysin (N-arginine dibasic convertase, or NRDc) is a cytosolic and cell-surface metalloendopeptidase that, in vitro, cleaves substrates upstream of Arg or Lys in basic pairs. NRDc differs from most of the other members of the M16 family of metalloendopeptidases by a 90 amino acid acidic domain (DAC) inserted close to its active site. At the cell surface, NRDc binds heparin-binding epidermal growth factor-like growth factor (HB-EGF) and enhances HB-EGF-induced cell migration. An active-site mutant of NRDc fulfills this function as well as wild-type NRDc, indicating that the enzyme activity is not required for this process. We now demonstrate that NRDc starts at Met(49). Furthermore, we show that HB-EGF not only binds to NRDc but also potently inhibits its enzymic activity. NRDc-HB-EGF interaction involves the 21 amino acid heparin-binding domain (P21) of the growth factor, the DAC of NRDc and most probably its active site. Only disulphide-bonded P21 dimers are inhibitory. We also show that Ca(2+), via the DAC, regulates both NRDc activity and HB-EGF binding. We conclude that the DAC is thus a key regulatory element for the two distinct functions that NRDc fulfills, i.e. as an HB-EGF modulator and a peptidase. PMID:12095415

  15. Heparin-binding growth factor type 1 (acidic fibroblast growth factor): a potential biphasic autocrine and paracrine regulator of hepatocyte regeneration.

    PubMed Central

    Kan, M; Huang, J S; Mansson, P E; Yasumitsu, H; Carr, B; McKeehan, W L

    1989-01-01

    Heparin-binding growth factor type 1 (HBGF-1; sometimes termed acidic fibroblast growth factor) is potentially an important factor in liver regeneration. HBGF-1 alone (half-maximal effect at 60 pM) stimulated hepatocyte DNA synthesis and bound to a high-affinity receptor (Kd = 62 pM; 5000 per cell). Epidermal growth factor (EGF) neutralized or masked the mitogenic effect of HBGF-1 concurrent with appearance of low-affinity HBGF-1 binding sites. HBGF-1 reduced the inhibitory effect of transforming growth factor type beta (TGF-beta) on the EGF stimulus. Nanomolar levels of HBGF-1 decreased the EGF stimulus. An increase in hepatic HBGF-1 gene expression after partial hepatectomy precedes increases in expression of the EGF homolog, TGF-alpha, and nonparenchymal-cell-derived TGF-beta in the regenerating liver. Expression of HBGF-1 mRNA occurs in both hepatocytes and nonparenchymal cells and persists for 7 days in liver tissue after partial hepatectomy. HBGF-1 acting through a high-affinity receptor is a candidate for the early autocrine stimulus that drives hepatocyte DNA synthesis prior to or concurrent with the EGF/TGF-alpha stimulus. It may allow hepatocyte proliferation to proceed in the presence of low levels of TGF-beta. An EGF/TGF-alpha-dependent change in HBGF-1 receptor phenotype and increasing levels of nonparenchymal-cell-derived HBGF-1 and TGF-beta may serve to limit hepatocyte proliferation. Images PMID:2477840

  16. Involvement of reactive oxygen species in stimuli-induced shedding of heparin-binding epidermal growth factor-like growth factor.

    PubMed

    Umata, Toshiyuki

    2014-06-01

    Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a critical growth factor for a number of physiological and pathological processes, such as wound healing, atherosclerosis and cancer proliferation. HB-EGF is synthesized as a membrane form (proHB-EGF), and is shedded at the cell surface to yield soluble HB-EGF, resulting in making it active. In this study, the involvement of reactive oxygen species (ROS) in stimuli-induced shedding of HB-EGF was investigated using monkey kidney Vero cells overexpressing HB-EGF (Vero-H cells). 12-O-tetradecanoylphorbol-13-acetate (TPA), lysophosphatidic acid (LPA) as a ligand for seventransmembrane G protein coupled receptors (GPCR) and sorbitol as stress induced shedding of HB-EGF mediated protein kinase C (PKC)-δ, mitogen-activated protein kinase (MAPK) and p38MAPK, respectively. These stimuli-induced sheddings of HB-EGF were inhibited by N-acetyl-L-cysteine (NAC), suggesting the involvement of ROS. As specific inhibitors of these protein kinases inhibited the shedding of HB-EGF, these signaling pathways seem to be independent, respectively. In contrast, γ-ray irradiation did not induce shedding although it did increase intracellular ROS levels. Taken together, these results suggest that the synergistic generation of ROS and the activation of protein kinase are required to promote stimuli-induced shedding of HB-EGF. PMID:24930874

  17. The Soluble Heparin-Binding EGF-Like Growth Factor Stimulates EGF Receptor Trafficking to the Nucleus

    PubMed Central

    Korotkevych, Nataliia V.; Labyntsev, Andrii Ju.; Kolybo, Denis V.; Komisarenko, Serhiy V.

    2015-01-01

    Most ligands of epidermal growth factor receptor (EGFR) have the ability to induce EGFR translocation into the nucleus, where EGFR acts as an important transcriptional regulator. Soluble form of heparin-binding EGF-like growth factor (sHB-EGF) is one of the ligands for EGFR in many cell types; however, there is no evidence for the ability of sHB-EGF to induce EGFR nuclear importation. Here, we demonstrated that treatment of A431 cells with sHB-EGF resulted in nuclear localization of EGFR and such translocation occurs via retrograde pathway. It was shown by confocal microscopy and co-immunoprecipitation assay that the translocation complex consisted of both ligand and receptor. The chromatin immunoprecipitation assay showed the association of sHB-EGF–EGFR complex with promoter region of cyclin D1 in the cell nucleus and this association was prevented by application of EGFR kinase inhibitor AG-1478. The obtained data suggest that sHB-EGF acts similarly to other EGFR ligands and is capable to induce EGFR nuclear translocation as a part of ligand-receptor complex in a tyrosine phosphorylation-dependent manner. PMID:26016774

  18. Heparin-Binding Epidermal Growth Factor and Its Receptors Mediate Decidualization and Potentiate Survival of Human Endometrial Stromal Cells

    PubMed Central

    Chobotova, Katya; Karpovich, Natalia; Carver, Janet; Manek, Sanjiv; Gullick, William J.; Barlow, David H.; Mardon, Helen J.

    2006-01-01

    Heparin-binding epidermal growth factor (HB-EGF) has pleiotropic biological functions in many tissues, including those of the female reproductive tract. It facilitates embryo development and mediates implantation and is thought to have a function in endometrial receptivity and maturation. The mature HB-EGF molecule manifests its activity as either a soluble factor (sol-HB-EGF) or a transmembrane precursor (tm-HB-EGF) and can bind two receptors, EGFR and ErbB4/HER4. In this study, we identify factors that modulate expression of HB-EGF, EGFR, and ErbB4 in endometrial stromal cells in vitro. We demonstrate that levels of sol- and tm-HB-EGF, EGFR, and ErbB4 are increased by cAMP, a potent inducer of decidualization of the endometrial stroma. We also show that production of sol- and tm-HB-EGF is differentially modulated by TNFα and TGFβ. Our data suggest that HB-EGF has a function in endometrial maturation in mediating decidualization and attenuating TNFα- and TGFβ-induced apoptosis of endometrial stromal cells. PMID:15562026

  19. Heparin-conjugated poly(lactic-co-glycolic acid) nanospheres enhance large-wound healing by delivering growth factors in platelet-rich plasma.

    PubMed

    La, Wan-Geun; Yang, Hee Seok

    2015-04-01

    Platelet-rich plasma (PRP) contains many growth factors that are involved in tissue regeneration processes. For successful tissue regeneration, protein growth factors require a delivery vehicle for long-term and sustained release to a defect site in order to maintain their bioactivity. Previously, we showed that heparin-conjugated poly(lactic-co-glycolic acid) nanospheres (HCPNs) can provide long-term delivery of growth factors with affinity for heparin. In this study, we hypothesize that treatment of a skin wound with a mixture of PRP and HCPNs would provide long-term delivery of several growth factors contained in PRP to promote the skin wound healing process with preservation of bioactivity. The release of platelet-derived growth factor-BB (PDGF-BB), contained in PRP, from HCPN with fibrin gel (FG) showed a prolonged release period versus a PRP mixture with FG alone (FG-PRP). Also, growth factors released from PRP with HCPN and FG showed sustained human dermal fibroblast growth for 12 days. Full-thickness skin wound treatment in mice with FG-HCPN-PRP resulted in much faster wound closure as well as dermal and epidermal regeneration at day 9 compared with treatment with FG-HCPN or FG-PRP. The enhanced wound healing using FG-HCPN-PRP may be due to the prolonged release not only of PDGF-BB but also of other growth factors in the PRP. The delivered growth factors accelerated angiogenesis at the wound site. PMID:25284020

  20. Heparin-binding epidermal growth factor-like growth factor in hippocampus: modulation of expression by seizures and anti-excitotoxic action.

    PubMed

    Opanashuk, L A; Mark, R J; Porter, J; Damm, D; Mattson, M P; Seroogy, K B

    1999-01-01

    The expression of heparin-binding epidermal growth factor-like growth factor (HB-EGF), an EGF receptor ligand, was investigated in rat forebrain under basal conditions and after kainate-induced excitotoxic seizures. In addition, a potential neuroprotective role for HB-EGF was assessed in hippocampal cultures. In situ hybridization analysis of HB-EGF mRNA in developing rat hippocampus revealed its expression in all principle cell layers of hippocampus from birth to postnatal day (P) 7, whereas from P14 through adulthood, expression decreased in the pyramidal cell layer versus the dentate gyrus granule cells. After kainate-induced excitotoxic seizures, levels of HB-EGF mRNA increased markedly in the hippocampus, as well as in several other cortical and limbic forebrain regions. In the hippocampus, HB-EGF mRNA expression increased within 3 hr after kainate treatment, continued to increase until 24 hr, and then decreased; increases occurred in the dentate gyrus granule cells, in the molecular layer of the dentate gyrus, and in and around hippocampal pyramidal CA3 and CA1 neurons. At 48 hr after kainate treatment, HB-EGF mRNA remained elevated in vulnerable brain regions of the hippocampus and amygdaloid complex. Western blot analysis revealed increased levels of HB-EGF protein in the hippocampus after kainate administration, with a peak at 24 hr. Pretreatment of embryonic hippocampal cell cultures with HB-EGF protected neurons against kainate toxicity. The kainate-induced elevation of [Ca2+]i in hippocampal neurons was not altered in cultures pretreated with HB-EGF, suggesting an excitoprotective mechanism different from that of previously characterized excitoprotective growth factors. Taken together, these results suggest that HB-EGF may function as an endogenous neuroprotective agent after seizure-induced neural activity/injury. PMID:9870945

  1. A modular, plasmin-sensitive, clickable poly(ethylene glycol)-heparin-laminin microsphere system for establishing growth factor gradients in nerve guidance conduits.

    PubMed

    Roam, Jacob L; Yan, Ying; Nguyen, Peter K; Kinstlinger, Ian S; Leuchter, Michael K; Hunter, Daniel A; Wood, Matthew D; Elbert, Donald L

    2015-12-01

    Peripheral nerve regeneration is a complex problem that, despite many advancements and innovations, still has sub-optimal outcomes. Compared to biologically derived acellular nerve grafts and autografts, completely synthetic nerve guidance conduits (NGC), which allow for precise engineering of their properties, are promising but still far from optimal. We have developed an almost entirely synthetic NGC that allows control of soluble growth factor delivery kinetics, cell-initiated degradability and cell attachment. We have focused on the spatial patterning of glial-cell derived human neurotrophic factor (GDNF), which promotes motor axon extension. The base scaffolds consisted of heparin-containing poly(ethylene glycol) (PEG) microspheres. The modular microsphere format greatly simplifies the formation of concentration gradients of reversibly bound GDNF. To facilitate axon extension, we engineered the microspheres with tunable plasmin degradability. 'Click' cross-linking chemistries were also added to allow scaffold formation without risk of covalently coupling the growth factor to the scaffold. Cell adhesion was promoted by covalently bound laminin. GDNF that was released from these microspheres was confirmed to retain its activity. Graded scaffolds were formed inside silicone conduits using 3D-printed holders. The fully formed NGC's contained plasmin-degradable PEG/heparin scaffolds that developed linear gradients in reversibly bound GDNF. The NGC's were implanted into rats with severed sciatic nerves to confirm in vivo degradability and lack of a major foreign body response. The NGC's also promoted robust axonal regeneration into the conduit. PMID:26352518

  2. Heparin-binding properties of human serum spreading factor.

    PubMed

    Barnes, D W; Reing, J E; Amos, B

    1985-08-01

    Human serum spreading factor (SF) is a blood glycoprotein that promotes attachment and spreading and influences growth, migration, and differentiation of a variety of animal cells in culture. SF purified from human plasma or serum by chromatographic methods reported previously (Barnes, D. W., and Silnutzer, J. (1983) J. Biol. Chem. 258, 12548-12552) does not bind to heparin-Sepharose under conditions of physiological ionic strength and pH. In a further examination of the heparin-binding properties of human serum SF, we found that exposure of purified SF to 8 M urea altered several properties of the protein, including heparin affinity, and these alterations remained after removal of the urea from SF solutions. Urea-treated SF bound to heparin under physiological conditions, and salt concentrations of 0.4 M or higher were required for elution of urea-treated SF from heparin-Sepharose at pH 7.0. The alteration of heparin-binding properties of SF also was observed upon exposure of the protein to heat or acid. Treatment of SF with urea, heat, or acid resulted additionally in greatly decreased cell spreading-promoting activity of the molecule. The decreased biological activity was associated with a reduced ability of the treated SF to bind to the cell culture substratum, a prerequisite for the attachment-promoting activity of the molecule. Experiments examining the heparin-binding properties of native SF in unfractionated human plasma indicated that the major portion of SF in blood did not bind to heparin under conditions of physiological ionic strength and pH. PMID:2410408

  3. The Mitogenic Potential of Heparin-Binding Epidermal Growth Factor in the Human Endometrium Is Mediated by the Epidermal Growth Factor Receptor and Is Modulated by Tumor Necrosis Factor

    PubMed Central

    CHOBOTOVA, KATYA; MUCHMORE, MARY-ELIZABETH; CARVER, JANET; YOO, HYUNG-J; MANEK, SANJIV; GULLICK, WILLIAM J.; BARLOW, DAVID H.; MARDON, HELEN J.

    2006-01-01

    Heparin-binding epidermal growth factor (HB-EGF), a member of the epidermal growth factor (EGF) family, is implicated in a variety of biological processes, including reproduction. Previous studies describe increased levels of HB-EGF in the human endometrium during the midsecretory stage of the menstrual cycle, suggesting a function for HB-EGF in implantation of the human blastocyst. Here we have investigated the expression and function of the soluble and transmembrane forms of HB-EGF in the human endometrium. We show that the expression of the transmembrane form of HB-EGF in the human endometrium is modulated according to the stage of the menstrual cycle. We present data demonstrating that both the soluble and transmembrane forms of HB-EGF induce DNA synthesis in human endometrial stromal cells. Furthermore, TNFα has a cooperative effect on HB-EGF, EGF, TGFα, and betacellulin-induced DNA synthesis in stromal cells, suggesting roles for the EGF family and TNFα in regeneration and maturation of human endometrium. Induction of DNA synthesis by HB-EGF and its modulation by TNFα in endometrial stromal cells are mediated by the EGF receptor and not the HB-EGF receptor ErbB4. Our data suggest key functions for HB-EGF, TNFα, and the EGF receptor in endometrial maturation, via autocrine/paracrine and juxtacrine pathways, in preparation for embryo implantation. PMID:12466384

  4. Biomedical Application of Low Molecular Weight Heparin/Protamine Nano/Micro Particles as Cell- and Growth Factor-Carriers and Coating Matrix

    PubMed Central

    Ishihara, Masayuki; Kishimoto, Satoko; Takikawa, Makoto; Hattori, Hidemi; Nakamura, Shingo; Shimizu, Masafumi

    2015-01-01

    Low molecular weight heparin (LMWH)/protamine (P) nano/micro particles (N/MPs) (LMWH/P N/MPs) were applied as carriers for heparin-binding growth factors (GFs) and for adhesive cells including adipose-derived stromal cells (ADSCs) and bone marrow-derived mesenchymal stem cells (BMSCs). A mixture of LMWH and P yields a dispersion of N/MPs (100 nm–3 μm in diameter). LMWH/P N/MPs can be immobilized onto cell surfaces or extracellular matrix, control the release, activate GFs and protect various GFs. Furthermore, LMWH/P N/MPs can also bind to adhesive cell surfaces, inducing cells and LMWH/P N/MPs-aggregate formation. Those aggregates substantially promoted cellular viability, and induced vascularization and fibrous tissue formation in vivo. The LMWH/P N/MPs, in combination with ADSCs or BMSCs, are effective cell-carriers and are potential promising novel therapeutic agents for inducing vascularization and fibrous tissue formation in ischemic disease by transplantation of the ADSCs and LMWH/P N/MPs-aggregates. LMWH/P N/MPs can also bind to tissue culture plates and adsorb exogenous GFs or GFs from those cells. The LMWH/P N/MPs-coated matrix in the presence of GFs may provide novel biomaterials that can control cellular activity such as growth and differentiation. Furthermore, three-dimensional (3D) cultures of cells including ADSCs and BMSCs using plasma-medium gel with LMWH/P N/MPs exhibited efficient cell proliferation. Thus, LMWH/P N/MPs are an adequate carrier both for GFs and for stromal cells such as ADSCs and BMSCs, and are a functional coating matrix for their cultures. PMID:26006248

  5. FGF growth factor analogs

    DOEpatents

    Zamora, Paul O.; Pena, Louis A.; Lin, Xinhua; Takahashi, Kazuyuki

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  6. The cell-penetrating peptide domain from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) has anti-inflammatory activity in vitro and in vivo

    SciTech Connect

    Lee, Jue-Yeon; Seo, Yoo-Na; Park, Hyun-Jung; Park, Yoon-Jeong; Chung, Chong-Pyoung

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer HBP sequence identified from HB-EGF has cell penetration activity. Black-Right-Pointing-Pointer HBP inhibits the NF-{kappa}B dependent inflammatory responses. Black-Right-Pointing-Pointer HBP directly blocks phosphorylation and degradation of I{kappa}B{alpha}. Black-Right-Pointing-Pointer HBP inhibits nuclear translocation of NF-{kappa}B p65 subunit. -- Abstract: A heparin-binding peptide (HBP) sequence from human heparin-binding epidermal growth factor-like growth factor (HB-EGF) was identified and was shown to exhibit cell penetration activity. This cell penetration induced an anti-inflammatory reaction in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages. HBP penetrated the cell membrane during the 10 min treatment and reduced the LPS-induced production of nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cytokines (TNF-{alpha} and IL-6) in a concentration-dependent manner. Additionally, HBP inhibited the LPS-induced upregulation of cytokines, including TNF-{alpha} and IL-6, and decreased the interstitial infiltration of polymorphonuclear leukocytes in a lung inflammation model. HBP inhibited NF-{kappa}B-dependent inflammatory responses by directly blocking the phosphorylation and degradation of I{kappa}B{alpha} and by subsequently inhibiting the nuclear translocation of the p65 subunit of NF-{kappa}B. Taken together, this novel HBP may be potentially useful candidate for anti-inflammatory treatments and can be combined with other drugs of interest to transport attached molecules into cells.

  7. Role of G protein-coupled estrogen receptor-1, matrix metalloproteinases 2 and 9, and heparin binding epidermal growth factor-like growth factor in estradiol-17β-stimulated bovine satellite cell proliferation.

    PubMed

    Kamanga-Sollo, E; Thornton, K J; White, M E; Dayton, W R

    2014-10-01

    In feedlot steers, estradiol-17β (E2) and combined E2 and trenbolone acetate (a testosterone analog) implants enhance rate and efficiency of muscle growth; and, consequently, these compounds are widely used as growth promoters. Although the positive effects of E2 on rate and efficiency of bovine muscle growth are well established, the mechanisms involved in these effects are not well understood. Combined E2 and trenbolone acetate implants result in significantly increased muscle satellite cell number in feedlot steers. Additionally, E2 treatment stimulates proliferation of cultured bovine satellite cells (BSC). Studies in nonmuscle cells have shown that binding of E2 to G protein-coupled estrogen receptor (GPER)-1 results in activation of matrix metalloproteinases 2 and 9 (MMP2/9) resulting in proteolytic release of heparin binding epidermal growth factor-like growth factor (hbEGF) from the cell surface. Released hbEGF binds to and activates the epidermal growth factor receptor resulting in increased proliferation. To assess if GPER-1, MMP2/9, and/or hbEGF are involved in the mechanism of E2-stimulated BSC proliferation, we have examined the effects of G36 (a specific inhibitor of GPER-1), CRM197 (a specific inhibitor of hbEGF), and MMP-2/MMP-9 Inhibitor II (an inhibitor of MMP2/9 activity) on E2-stimulated BSC proliferation. Inhibition of GPER-1, MMP2/9, or hbEGF suppresses E2-stimulated BSC proliferation (P < 0.001) suggesting that all these are required in order for E2 to stimulate BSC proliferation. These results strongly suggest that E2 may stimulate BSC proliferation by binding to GPER-1 resulting in MMP2/9-catalyzed release of cell membrane-bound hbEGF and subsequent activation of epidermal growth factor receptor by binding of released hbEGF. PMID:25010024

  8. Controlled dual delivery of fibroblast growth factor-2 and Interleukin-10 by heparin-based coacervate synergistically enhances ischemic heart repair.

    PubMed

    Chen, William C W; Lee, Brandon G; Park, Dae Woo; Kim, Kyobum; Chu, Hunghao; Kim, Kang; Huard, Johnny; Wang, Yadong

    2015-12-01

    Myocardial infarction (MI) causes myocardial necrosis, triggers chronic inflammatory responses, and leads to pathological remodeling. Controlled delivery of a combination of angiogenic and immunoregulatory proteins may be a promising therapeutic approach for MI. We investigated the bioactivity and therapeutic potential of an injectable, heparin-based coacervate co-delivering an angiogenic factor, fibroblast growth factor-2 (FGF2), and an anti-inflammatory cytokine, Interleukin-10 (IL-10) in a spatially and temporally controlled manner. Coacervate delivery of FGF2 and IL-10 preserved their bioactivities on cardiac stromal cell proliferation in vitro. Upon intramyocardial injection into a mouse MI model, echocardiography revealed that FGF2/IL-10 coacervate treated groups showed significantly improved long-term LV contractile function and ameliorated LV dilatation. FGF2/IL-10 coacervate substantially augmented LV myocardial elasticity. Additionally, FGF2/IL-10 coacervate notably enhanced long-term revascularization, especially at the infarct area. In addition, coacervate loaded with 500 ng FGF2 and 500 ng IL-10 significantly reduced LV fibrosis, considerably preserved infarct wall thickness, and markedly inhibited chronic inflammation at the infarct area. These results indicate that FGF2/IL-10 coacervate has notably greater therapeutic potential than coacervate containing only FGF2. Overall, our data suggest therapeutically synergistic effects of FGF-2/IL-10 coacervate, particularly coacervate with FGF2 and 500 ng IL-10, for the treatment of ischemic heart disease. PMID:26370927

  9. Latent transforming growth factor β-binding protein-3 and fibulin-1C interact with the extracellular domain of the heparin-binding EGF-like growth factor precursor

    PubMed Central

    Brooke, Joanna S; Cha, Jeong-Heon; Eidels, Leon

    2002-01-01

    Background The membrane-bound cell-surface precursor and soluble forms of heparin-binding epidermal growth factor-like growth factor (HB-EGF) contribute to many cellular developmental processes. The widespread occurrence of HB-EGF in cell and tissue types has led to observations of its role in such cellular and tissue events as tumor formation, cell migration, extracellular matrix formation, wound healing, and cell adherence. Several studies have reported the involvement of such extracellular matrix proteins as latent transforming growth factor β-binding protein, TGF-β, and fibulin-1 in some of these processes. To determine whether HB-EGF interacts with extracellular matrix proteins we used the extracellular domain of proHB-EGF in a yeast two-hybrid system to screen a monkey kidney cDNA library. cDNA clones containing nucleotide sequences encoding domains of two proteins were obtained and their derived amino acid sequences were evaluated. Results From ≈ 3 × 106 screened monkey cDNA clones, cDNA clones were recovered that contained nucleotide sequences encoding domains of the monkey latent transforming growth factor-β binding protein-3 (MkLTBP-3) and fibulin-1C protein. The amino acid sequence derived from the MkLTBP-3 gene shared 98.6% identity with human LTBP-3 and 86.7% identity with mouse LTBP-3 amino acid sequences. The amino acid sequence derived from the monkey fibulin-1C gene shared 97.2% identity with human fibulin-1C. Yeast two-hybrid screens indicate that LTBP-3 and fibulin-1C interact with proHB-EGF through their calcium-binding EGF-like modules. Conclusions The interactions of the extracellular domain of proHB-EGF with LTBP-3 and fibulin-1C suggest novel functions for HB-EGF between cell and tissue surfaces. PMID:11846885

  10. Sustained dual release of placental growth factor-2 and bone morphogenic protein-2 from heparin-based nanocomplexes for direct osteogenesis

    PubMed Central

    Liu, Yun; Deng, Li-Zhi; Sun, Hai-Peng; Xu, Jia-Yun; Li, Yi-Ming; Xie, Xin; Zhang, Li-Ming; Deng, Fei-Long

    2016-01-01

    Objective To compare the direct osteogenic effect between placental growth factor-2 (PlGF-2) and bone morphogenic protein-2 (BMP-2). Methods Three groups of PlGF-2/BMP-2-loaded heparin–N-(2-hydroxyl) propyl-3-trimethyl ammonium chitosan chloride (HTCC) nanocomplexes were prepared: those with 0.5 μg PlGF-2; with 1.0 μg BMP-2; and with 0.5 μg PlGF-2 combined with 1.0 μg BMP-2. The loading efficiencies and release profiles of these growth factors (GFs) in this nanocomplex system were quantified using enzyme-linked immunosorbent assay, their biological activities were evaluated using cell counting kit-8, cell morphology, and cell number counting assays, and their osteogenic activities were quantified using alkaline phosphatase and Alizarin Red S staining assays. Results The loading efficiencies were more than 99% for the nanocomplexes loaded with just PlGF-2 and for those loaded with both PlGF-2 and BMP-2. For the nanocomplex loaded with just BMP-2, the loading efficiency was more than 97%. About 83%–84% of PlGF-2 and 89%–91% of BMP-2 were stably retained on the nanocomplexes for at least 21 days. In in vitro biological assays, PlGF-2 exhibited osteogenic effects comparable to those of BMP-2 despite its dose in the experiments being lower than that of BMP-2. Moreover, the results implied that heparin-based nanocomplexes encapsulating two GFs have enhanced potential in the enhancement of osteoblast function. Conclusion PlGF-2-loaded heparin–HTCC nanocomplexes may constitute a promising system for bone regeneration. Moreover, the dual delivery of PlGF-2 and BMP-2 appears to have greater potential in bone tissue regeneration than the delivery of either GFs alone. PMID:27042064

  11. Binding of heparin to human platelet factor 4.

    PubMed Central

    Cowan, S W; Bakshi, E N; Machin, K J; Isaacs, N W

    1986-01-01

    Platelet factor 4 is a small protein (Mr 7756) from the alpha-granules of blood platelets which binds strongly to and neutralizes the anticoagulant properties of heparin. From an analysis of X-ray crystallographic data a model for the binding of platelet factor 4 to heparin is proposed. PMID:3718482

  12. Heparin localization and fine structure regulate Burkitt's lymphoma growth

    SciTech Connect

    Berry, David; Lynn, David M.; Berry, Eric; Sasisekharan, Ram; Langer, Robert . E-mail: rlanger@mit.edu

    2006-09-29

    Burkitt's lymphoma (BL) is a B-cell malignancy associated with the Epstein-Barr virus (EBV). Mounting evidence has implicated heparan sulfate proteoglycans and heparan sulfate-like glycosaminoglycans (HSGAGs) in the initiation, severity, and progression of the malignancy. The importance of HSGAGs in regulating BL cell growth was therefore examined. Extracellular exogenous heparin inhibited cell growth >30%, while heparin internalized with poly({beta}-amino ester)s promoted proliferation up to 58%. The growth-modulating effects of heparin and internalized heparin were dependent on cell surface HSGAGs, PI3K, and Erk/Mek. Treatment of cells with protamine sulfate or with heparinases potently inhibited proliferation, with the greatest effects induced by heparinase I. Cell surface HSGAGs therefore play an important role in regulating BL proliferation and may offer a potential target for therapeutic intervention.

  13. Conditional loss of heparin-binding EGF-like growth factor results in enhanced liver fibrosis after bile duct ligation in mice

    SciTech Connect

    Takemura, Takayo; Yoshida, Yuichi; Kiso, Shinichi; Kizu, Takashi; Furuta, Kunimaro; Ezaki, Hisao; Hamano, Mina; Egawa, Mayumi; Chatani, Norihiro; Kamada, Yoshihiro; Imai, Yasuharu; Higashiyama, Shigeki; Iwamoto, Ryo; Mekada, Eisuke; Takehara, Tetsuo

    2013-07-26

    Highlights: •HB-EGF expression was increased during the development of liver fibrosis. •Conditional HB-EGF knockout mouse showed enhanced experimental liver fibrosis. •HB-EGF antagonized TGF-β-induced activation of hepatic stellate cells. •We report a possible protective role of HB-EGF in cholestatic liver fibrosis. -- Abstract: Our aims were to evaluate the involvement of heparin-binding EGF-like growth factor (HB-EGF) in liver fibrogenesis of humans and mice and to elucidate the effect of HB-EGF deficiency on cholestatic liver fibrosis using conditional HB-EGF knockout (KO) mice. We first demonstrated that gene expression of HB-EGF had a positive significant correlation with that of collagen in human fibrotic livers, and was increased in bile duct ligation (BDL)-induced fibrotic livers in mouse. We then generated conditional HB-EGF knockout (KO) mice using the interferon inducible Mx-1 promoter driven Cre recombinase transgene and wild type (WT) and KO mice were subjected to BDL. After BDL, KO mice exhibited enhanced liver fibrosis with increased expression of collagen, compared with WT mice. Finally, we used mouse hepatic stellate cells (HSCs) to examine the role of HB-EGF in the activation of these cells and showed that HB-EGF antagonized TGF-β-induced gene expression of collagen in mouse primary HSCs. Interestingly, HB-EGF did not prevent the TGF-β-induced nuclear accumulation of Smad3, but did lead to stabilization of the Smad transcriptional co-repressor TG-interacting factor. In conclusion, our data suggest a possible protective role of HB-EGF in cholestatic liver fibrosis.

  14. The anti-tumor effect of cross-reacting material 197, an inhibitor of heparin-binding EGF-like growth factor, in human resistant ovarian cancer

    SciTech Connect

    Tang, Xiao-han; Deng, Suo; Li, Meng; Lu, Mei-song

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer HB-EGF over-expression in A2780/Taxol, A2780/CDDP cells and the matched xenografts. Black-Right-Pointing-Pointer CRM197 induces enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. Black-Right-Pointing-Pointer CRM197 arrests A2780/Taxol and A2780/CDDP cells at G0/G1 phase. Black-Right-Pointing-Pointer CRM197 suppressed the A2780/Taxol and A2780/CDDP growth of xenografts. -- Abstract: Heparin-binding epidermal growth factor-like growth factor (HB-EGF) is a promising target for ovarian cancer therapy. Cross-reacting material 197 (CRM197), a specific HB-EGF inhibitor, has been proven to represent possible chemotherapeutic agent for ovarian cancer. However, the effect of CRM197 on the resistant ovarian carcinoma cells has not been sufficiently elucidated. Here, we found that HB-EGF was over-expressed in a paclitaxel-resistant human ovarian carcinoma cell line (A2780/Taxol) and a cisplatin-resistant cell line (A2780/CDDP), as well as the xenograft mouse tissue samples with these cells. To investigate the possible significance of the HB-EGF over-expression in A2780/Taxol and A2780/CDDP cells, we inhibited HB-EGF expression by CRM197 to investigate the effect of CRM197 treatment on these cells. We observed that CRM197 significantly induced anti-proliferative activity in a dose-dependent manner with the cell-cycle arrest at the G0/G1 phase and enhanced apoptosis in A2780/Taxol and A2780/CDDP cells. The sensitive ovarian carcinoma parental cell line (A2780), A2780/Taxol and A2780/CDDP cells formed tumors in nude mice, and enhanced tumorigenicity was observed in drug-resistant tumors. Furthermore, we observed that CRM197 significantly suppressed the growth of drug-resistant ovarian cancer xenografts in vivo (p < 0.001). These results suggest that CRM197 as an HB-EGF-targeted agent has potent anti-tumor activity in paclitaxel- and cisplatin-resistant ovarian cancer which over-express HB-EGF.

  15. Heparin platelet factor 4 antibody positivity in pseudothrombocytopenia.

    PubMed

    Balcik, Ozlem Sahin; Akdeniz, Derya; Cipil, Handan; Uysal, Sema; Isik, Ayse; Kosar, Ali

    2012-01-01

    Pseudothrombocytopenia (PTCP) is a laboratory event of platelet clustering related to drugs used for anticoagulation. This condition is engendered by autoantibodies against platelets in usually EDTA-anticoagulated blood. Pseudothrombocytopenia has no clinical significance but when evaluated as true thrombocytopenia, this misconception may lead to unnecessary diagnostic procedures. Heparin-induced thrombocytopenia with thrombosis (HITT) is a complication of heparin treatment caused by heparin platelet factor 4 (HPF-4) antibodies, leading to platelet activation and hypercoagulability. In our study, 48 patients with PTCP and 36 healthy volunteers were included. Heparin platelet factor 4 antibody positivity was detected in 12 patients from PTCP group; nobody from control group had. Citrated serum samples and peripheral blood smears showed normal platelet count. Of the 4 patients using heparin derivative, 1 (2.1%) had antibody positivity but without any bleeding symptoms. In conclusion, HPF-4 antibody positivity might be a risk factor for PTCP. Clinicians should be aware of this kind of condition. PMID:21593020

  16. Effect of antigen-dependent clearance on pharmacokinetics of anti-heparin-binding EGF-like growth factor (HB-EGF) monoclonal antibody.

    PubMed

    Kasai, Noriyuki; Yoshikawa, Yukitaka; Enokizono, Junichi

    2014-01-01

    Heparin-binding EGF-like growth factor (HB-EGF) is a member of the EGF family and is an important therapeutic target in some types of human cancers. KM3566 is a mouse anti-HB-EGF monoclonal antibody that neutralizes HB-EGF activity by inhibiting the binding of HB-EGF to its receptors. Based on the results of our pharmacokinetics study, a humanized derivative antibody, KHK2866, is rapidly cleared from serum and shows nonlinear pharmacokinetics in cynomolgus monkeys. In this study, we examined the antigen-dependent clearance of an anti-HB-EGF monoclonal antibody in vivo and in vitro in order to pharmacokinetically explain the rapid elimination of KHK2866. We revealed tumor size-dependent clearance of KM3566 in in vivo studies and obtained good fits between the observed and simulated concentrations of KM3566 based on the two-compartment with a saturable route of clearance model. Furthermore, in vivo imaging analyses demonstrated tumor-specific distribution of KM3566. We then confirmed rapid internalization and distribution to lysosome of KM3566 at a cellular level. Moreover, we revealed that the amounts of HB-EGF on cell surface membrane were maintained even while HB-EGF was internalized with KM3566. Recycled or newly synthesized HB-EGF, therefore, may contribute to a consecutive clearance of KM3566, which could explain a rapid clearance from serum. These data suggested that the rapid elimination in pharmacokinetics of KM3566 is due to antigen-dependent clearance. Given that its antigen is expressed in a wide range of normal tissue, it is estimated that the rapid elimination of KHK2866 from cynomolgus monkey serum is caused by antigen-dependent clearance. PMID:25517307

  17. Identification of tyrosines 154 and 307 in the extracellular domain and 653 and 766 in the intracellular domain as phosphorylation sites in the heparin-binding fibroblast growth factor receptor tyrosine kinase (flg).

    PubMed Central

    Hou, J.; McKeehan, K.; Kan, M.; Carr, S. A.; Huddleston, M. J.; Crabb, J. W.; McKeehan, W. L.

    1993-01-01

    Four tyrosine residues have been identified as phosphorylation sites in the tyrosine kinase isoform of the heparin-binding fibroblast growth factor receptor flg (FGF-R1). Baculoviral-insect cell-derived recombinant FGF-R1 was phosphorylated and fragmented with trypsin while immobilized on heparin-agarose beads. Phosphotyrosine peptides were purified by chromatography on immobilized anti-phosphotyrosine antibody and analyzed by Edman degradation and electrospray tandem mass spectrometry. Tyrosine residue 653, which is in a homologous spatial position to major autophosphorylation sites in the catalytic domain of the src and insulin receptor kinases, is the major intracellular FGF-R1 phosphorylation site. Residue 766 in the COOH-terminus outside the kinase domain is a secondary site. Tyrosine residues 154 and 307, which are in the extracellular domain of transmembrane receptor isoforms and are in an unusual sequence context for tyrosine phosphorylation, were also phosphorylated. PMID:8443592

  18. G3139, an Anti-Bcl-2 Antisense Oligomer that Binds Heparin-Binding Growth Factors and Collagen I, Alters In Vitro Endothelial Cell Growth and Tubular Morphogenesis

    PubMed Central

    Stein, C.A.; Wu, SiJian; Voskresenskiy, Anatoliy M.; Zhou, Jin-Feng; Shin, Joongho; Miller, Paul; Souleimanian, Naira; Benimetskaya, Luba

    2009-01-01

    Purpose We examined the effects of G3139 on the interaction of heparin-binding proteins (e.g., FGF2 and collagen I) with endothelial cells. G3139 is an 18mer phosphorothioate oligonucleotide targeted to the initiation codon region of the Bcl-2 mRNA. A randomized, prospective global Phase III trial in advanced melanoma (GM301) has evaluted G3139 in combination with dacarbazine. However, the mechanism of action of G3139 is incompletely understood, as it is unlikely that Bcl-2 silencing is the sole mechanism for chemo-sensitization in melanoma cells. Experimental Design The ability of G3139 to interact with and protect heparin-binding proteins was quantitated. The effects of G3139 on the binding of FGF2 to high affinity cell surface receptors, and the induction of cellular mitogenesis and tubular morphogenesis in HMEC-1 and HUVEC cells were determined. Results G3139 binds with picomolar affinity to collagen I. By replacing heparin, the drug can potentiate the binding of FGF2 to FGFR1 IIIc, and it protects FGF from oxidation and from proteolysis. G3139 can increase endothelial cell mitogenesis and tubular morphogenesis of HMEC-1 cells in 3D collagen gels, increases the mitogenesis of HUVEC cells similarly, and induces vessel sprouts in the rat aortic ring model. Conclusions G3139 dramatically affects the behavior of endothelial cells. There may be a correlation between this observation and the treatment interaction with LDH observed clinically. PMID:19351753

  19. In vitro effects of heparin and tissue factor pathway inhibitor on factor VII assays. possible implications for measurements in vivo after heparin therapy.

    PubMed

    Bladbjerg, E M; Larsen, L F; Ostergaard, P; Jespersen, J

    2000-12-01

    The coagulant activity of blood coagulation factor VII (FVII:C) can be lowered by changes in lifestyle and by therapeutic intervention, e.g. heparin infusion. The question is, however, whether FVII:C determined ex vivo is a valid measure of the FVII activity in vivo. We measured plasma FVII:C, activated FVII (FVIIa), FVII protein (FVII:Ag), tissue factor pathway inhibitor (TFPI), triglycerides, and free fatty acids (FFA) before and 15 min after infusion of a bolus of unfractionated heparin (50 IU/kg body weight) in 12 healthy subjects. Additionally, we conducted in vitro experiments to investigate the effect of unfractionated heparin and TFPI, which is released from the endothelium by heparin, on FVII:C, FVIIa, and FVII:Ag. Heparin infusion decreased triglycerides and increased FFA and TFPI. This was accompanied by significant reductions in FVIIa, FVII:C and FVII:Ag. In vitro, anti-TFPI antibodies increased FVIIa and FVII:C, and heparin reduced FVIIa. The heparinase Hepzyme was unable to abolish the effect of heparin. There were no in vitro effects on FVII:Ag. We conclude that, due to interference by TFPI and heparin in post-heparin plasma, it is impossible to measure the in vivo FVII activity by means of FVII clotting assays. These assays should therefore not be used to measure the coagulation status of patients in heparin therapy, unless extraordinary precautions are taken to eliminate TFPI and heparin effects ex vivo. The observed effect of heparin on FVII:Ag should be investigated further. PMID:11132652

  20. Active G protein-coupled receptors (GPCR), matrix metalloproteinases 2/9 (MMP2/9), heparin-binding epidermal growth factor (hbEGF), epidermal growth factor receptor (EGFR), erbB2, and insulin-like growth factor 1 receptor (IGF-1R) are necessary for trenbolone acetate-induced alterations in protein turnover rate of fused bovine satellite cell cultures.

    PubMed

    Thornton, K J; Kamanga-Sollo, E; White, M E; Dayton, W R

    2016-06-01

    Trenbolone acetate (TBA), a testosterone analog, increases protein synthesis and decreases protein degradation in fused bovine satellite cell (BSC) cultures. However, the mechanism through which TBA alters these processes remains unknown. Recent studies indicate that androgens improve rate and extent of muscle growth through a nongenomic mechanism involving G protein-coupled receptors (GPCR), matrix metalloproteinases (MMP), heparin-binding epidermal growth factor (hbEGF), the epidermal growth factor receptor (EGFR), erbB2, and the insulin-like growth factor-1 receptor (IGF-1R). We hypothesized that TBA activates GPCR, resulting in activation of MMP2/9 that releases hbEGF, which activates the EGFR and/or erbB2. To determine whether the proposed nongenomic pathway is involved in TBA-mediated alterations in protein turnover, fused BSC cultures were treated with TBA in the presence or absence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R, and resultant protein synthesis and degradation rates were analyzed. Assays were replicated at least 9 times for each inhibitor experiment utilizing BSC cultures obtained from at least 3 different steers that had no previous exposure to steroid compounds. As expected, fused BSC cultures treated with 10 n TBA exhibited increased ( < 0.05) protein synthesis rates and decreased ( < 0.05) protein degradation rates when compared to control cultures. Treatment of fused BSC cultures with 10 n TBA in the presence of inhibitors for GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R suppressed ( < 0.05) TBA-mediated increases in protein synthesis rate. Alternatively, inhibition of GPCR, MMP2/9, hbEGF, EGFR, erbB2, or IGF-1R in the presence of 10 n TBA each had no ( > 0.05) effect on TBA-mediated decreases in protein degradation. However, inhibition of both EGFR and erbB2 in the presence of 10 n TBA resulted in decreased ( < 0.05) ability of TBA to decrease protein degradation rate. Additionally, fused BSC cultures treated with 10 n

  1. Mechanical prophylaxis is a heparin-independent risk for anti–platelet factor 4/heparin antibody formation after orthopedic surgery

    PubMed Central

    Bito, Seiji; Migita, Kiyoshi; Nakamura, Mashio; Shinohara, Kazuhito; Sato, Tomotaro; Tonai, Takeharu; Shimizu, Motoyuki; Shibata, Yasuhiro; Kishi, Kazuhiko; Kubota, Chikara; Nakahara, Shinnosuke; Mori, Toshihito; Ikeda, Kazuo; Ota, Shusuke; Minamizaki, Takeshi; Yamada, Shigeru; Shiota, Naofumi; Kamei, Masataka; Motokawa, Satoru

    2016-01-01

    Platelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366. PMID:26659923

  2. Mechanical prophylaxis is a heparin-independent risk for anti-platelet factor 4/heparin antibody formation after orthopedic surgery.

    PubMed

    Bito, Seiji; Miyata, Shigeki; Migita, Kiyoshi; Nakamura, Mashio; Shinohara, Kazuhito; Sato, Tomotaro; Tonai, Takeharu; Shimizu, Motoyuki; Shibata, Yasuhiro; Kishi, Kazuhiko; Kubota, Chikara; Nakahara, Shinnosuke; Mori, Toshihito; Ikeda, Kazuo; Ota, Shusuke; Minamizaki, Takeshi; Yamada, Shigeru; Shiota, Naofumi; Kamei, Masataka; Motokawa, Satoru

    2016-02-25

    Platelet-activating antibodies, which recognize platelet factor 4 (PF4)/heparin complexes, induce spontaneous heparin-induced thrombocytopenia (HIT) syndrome or fondaparinux-associated HIT without exposure to unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH). This condition mostly occurs after major orthopedic surgery, implying that surgery itself could trigger this immune response, although the mechanism is unclear. To investigate how surgery may do so, we performed a multicenter, prospective study of 2069 patients who underwent total knee arthroplasty (TKA) or hip arthroplasty. Approximately half of the patients received postoperative thromboprophylaxis with UFH, LMWH, or fondaparinux. The other half received only mechanical thromboprophylaxis, including dynamic (intermittent plantar or pneumatic compression device), static (graduated compression stockings [GCSs]), or both. We measured anti-PF4/heparin immunoglobulins G, A, and M before and 10 days after surgery using an immunoassay. Multivariate analysis revealed that dynamic mechanical thromboprophylaxis (DMT) was an independent risk factor for seroconversion (odds ratio [OR], 2.01; 95% confidence interval [CI], 1.34-3.02; P = .001), which was confirmed with propensity-score matching (OR, 1.99; 95% CI, 1.17-3.37; P = .018). For TKA, the seroconversion rates in patients treated with DMT but no anticoagulation and in patients treated with UFH or LMWH without DMT were similar, but significantly higher than in patients treated with only GCSs. The proportion of patients with ≥1.4 optical density units appeared to be higher among those treated with any anticoagulant plus DMT than among those not treated with DMT. Our study suggests that DMT increases risk of an anti-PF4/heparin immune response, even without heparin exposure. This trial was registered to www.umin.ac.jp/ctr as #UMIN000001366. PMID:26659923

  3. Interactions between nattokinase and heparin/GAGs.

    PubMed

    Zhang, Fuming; Zhang, Jianhua; Linhardt, Robert J

    2015-12-01

    Nattokinase (NK) is a serine protease extracted from a traditional Japanese food called natto. Due to its strong fibrinolytic and thrombolytic activity, NK is regarded as a valuable dietary supplement or nutraceutical for the oral thrombolytic therapy. In addition, NK has been investigated for some other medical applications including treatment of hypertension, Alzheimer's disease, and vitreoretinal disorders. The most widely used clinical anticoagulants are heparin and low molecular weight heparins. The interactions between heparin and proteins modulate diverse patho-physiological processes and heparin modifies the activity of serine proteases. Indeed, heparin plays important roles in almost all of NK's potential therapeutically applications. The current report relies on surface plasmon resonance spectroscopy to examine NK interacting with heparin as well as other glycosaminoglycans (GAGs). These studies showed that NK is a heparin binding protein with an affinity of ~250 nM. Examination with differently sized heparin oligosaccharides indicated that the interaction between NK and heparin is chain-length dependent and the minimum size for heparin binding is a hexasaccharide. Studies using chemically modified heparin showed the 6-O-sulfo as well as the N-sulfo groups but not the 2-O-sulfo groups within heparin, are essential for heparin's interaction with NK. Other GAGs (including HS, DS, and CSE) displayed modest binding affinity to NK. NK also interfered with other heparin-protein interactions, including heparin's interaction with antithrombin and fibroblast growth factors. PMID:26412225

  4. Antibodies from patients with heparin-induced thrombocytopenia/thrombosis are specific for platelet factor 4 complexed with heparin or bound to endothelial cells.

    PubMed Central

    Visentin, G P; Ford, S E; Scott, J P; Aster, R H

    1994-01-01

    Heparin-induced thrombocytopenia/thrombosis (HITP) is thought to be mediated by immunoglobulins that activate platelets in the presence of pharmacologic concentrations of heparin, but the molecular basis for this relatively common and often serious complication of heparin therapy has not been established. We found that plasma from each of 12 patients with HITP contained high titer (> or = 1:200) antibodies that reacted with immobilized complexes of heparin and platelet factor 4 (PF4), a heparin-binding protein contained in platelet alpha-granules. Recombinant human PF4 behaved similarly to PF4 isolated from platelets in this assay system. Complexes formed at an apparent heparin/PF4 molecular ratio of approximately 1:2 (fresh heparin) and approximately 1:12 (outdated heparin) were most effective in binding antibody. Immune complexes consisting of PF4, heparin, and antibody reacted with resting platelets; this interaction was inhibited by a monoclonal antibody specific for the Fc gamma RII receptor and by excess heparin. Human umbilical vein endothelial cells, known to express heparin-like glycosaminoglycan molecules on their surface, were recognized by antibody in the presence of PF4 alone; this reaction was inhibited by excess heparin, but not by anti-Fc gamma RII. Antibodies reactive with heparin/PF4 were not found in normal plasma, but IgG and IgM antibodies were detected at dilutions of 1:10 (IgG) and 1:50 (IgM) in 3 of 50 patients (6%) with other types of immune thrombocytopenia. These findings indicate that antibodies associated with HITP react with PF4 complexed with heparin in solution or with glycosaminoglycan molecules on the surface of endothelial cells and provide the basis for a new hypothesis to explain the development of thrombocytopenia with thrombosis or disseminated intravascular coagulation in patients sensitive to heparin. PMID:8282825

  5. The heparin binding domain of vitronectin is the region that is required to enhance insulin-like growth factor-I signaling.

    PubMed

    Maile, Laura A; Busby, Walker H; Sitko, Kevin; Capps, Byron E; Sergent, Tiffany; Badley-Clarke, Jane; Ling, Yan; Clemmons, David R

    2006-04-01

    We have shown that vitronectin (Vn) binding to a cysteine loop sequence within the extracellular domain of the beta3-subunit (amino acids 177-184) of alphaVbeta3 is required for the positive effects of Vn on IGF-I signaling. When Vn binding to this sequence is blocked, IGF-I signaling in smooth muscle cells is impaired. Because this binding site is distinct from the site on beta3 to which the Arg-Gly-Asp sequence of extracellular matrix ligands bind (amino acids 107-171), we hypothesized that the region of Vn that binds to the cysteine loop on beta3 is distinct from the region that contains the Arg-Gly-Asp sequence. The results presented in this study demonstrate that this heparin binding domain (HBD) is the region of Vn that binds to the cysteine loop region of beta3 and that this region is sufficient to mediate the positive effects of Vn on IGF-I signaling. We provide evidence that binding of the HBD of Vn to alphaVbeta3 has direct effects on the activation state of beta3 as measured by beta3 phosphorylation. The increase in beta3 phosphorylation associated with exposure of cells to this HBD is associated with enhanced phosphorylation of the adaptor protein Src homology 2 domain-containing transforming protein C and enhanced activation MAPK, a downstream mediator of IGF-I signaling. We conclude that the interaction of the HBD of Vn binding to the cysteine loop sequence of beta3 is necessary and sufficient for the positive effects of Vn on IGF-I-mediated effects in smooth muscle cells. PMID:16322097

  6. Modulation of heparin cofactor II activity by histidine-rich glycoprotein and platelet factor 4.

    PubMed Central

    Tollefsen, D M; Pestka, C A

    1985-01-01

    Heparin cofactor II is a plasma protein that inhibits thrombin rapidly in the presence of either heparin or dermatan sulfate. We have determined the effects of two glycosaminoglycan-binding proteins, i.e., histidine-rich glycoprotein and platelet factor 4, on these reactions. Inhibition of thrombin by heparin cofactor II and heparin was completely prevented by purified histidine-rich glycoprotein at the ratio of 13 micrograms histidine-rich glycoprotein/microgram heparin. In contrast, histidine-rich glycoprotein had no effect on inhibition of thrombin by heparin cofactor II and dermatan sulfate at ratios of less than or equal to 128 micrograms histidine-rich glycoprotein/microgram dermatan sulfate. Removal of 85-90% of the histidine-rich glycoprotein from plasma resulted in a fourfold reduction in the amount of heparin required to prolong the thrombin clotting time from 14 s to greater than 180 s but had no effect on the amount of dermatan sulfate required for similar anti-coagulant activity. In contrast to histidine-rich glycoprotein, purified platelet factor 4 prevented inhibition of thrombin by heparin cofactor II in the presence of either heparin or dermatan sulfate at the ratio of 2 micrograms platelet factor 4/micrograms glycosaminoglycan. Furthermore, the supernatant medium from platelets treated with arachidonic acid to cause secretion of platelet factor 4 prevented inhibition of thrombin by heparin cofactor II in the presence of heparin or dermatan sulfate. We conclude that histidine-rich glycoprotein and platelet factor 4 can regulate the antithrombin activity of heparin cofactor II. Images PMID:3838317

  7. Two Novel Heparin-binding Vascular Endothelial Growth Factor Splices, L-VEGF144 and L-VEGF138, are Expressed in Human Glioblastoma Cells.

    PubMed

    Shen, Chiung-Chyi; Cheng, Wen-Yu; Chiao, Ming-Tsang; Liang, Yea-Jiuan; Mao, Tsuo-Fei; Liu, Bai-Shuan

    2016-01-01

    The expression levels of different vascular endothelial growth factor A (VEGF) isoforms are associated with the angiogenesis and the patient's prognoses in human cancers. Ribosomes specifically scan from 5' to 3' CUG initiation codon in the long 5'-untranslated region (5'-UTR) of the VEGF mRNA, resulting in the generation of high mol wt VEGF isoform [call large VEGF (L-VEGF)]. Alternative splicing of VEGF mRNA transcripts results in several isoforms with distinct properties that are dependent up their exon compositions. In this study, we observed two novel kinds of splicing VEGF isoforms that transcripted at the first upstream CUG codon, and which we have named large-VEGF144 (LVEGF144), and large-VEGF138 (L-VEGF138). The expression levels of messenger RNA for the different VEGF splice forms were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR). After DNA sequencing, the genetic structure of L-VEGF144 involved not only a partial exon 1, exon 6a, and exons 7-8, but also an unique 108- nucleotides insertion of VEGF intron 5 interposed between exon 1 and exon 6. At the same time, L-VEGF144 lacked most of the Nterminal fragments (exons 1-5). We further found that a specific detection model could easily and rapidly confirm the presence of L-VEGF144 mRNA fragments in the biopsies or cell lines via RT-PCR assay. In addition, we used visible fluorescent fusion proteins to prove that both L-VEGF144 and L-VEGF138 have nuclear localization ability. Taken together, the findings of this study indicate that, unlike previously identified isoforms, these novel VEGF isoforms are likely to suggest a further level of complexity in the angiogenic process. PMID:27220431

  8. Identification of Candidate Angiogenic Inhibitors Processed by Matrix Metalloproteinase 2 (MMP-2) in Cell-Based Proteomic Screens: Disruption of Vascular Endothelial Growth Factor (VEGF)/Heparin Affin Regulatory Peptide (Pleiotrophin) and VEGF/Connective Tissue Growth Factor Angiogenic Inhibitory Complexes by MMP-2 Proteolysis▿ †

    PubMed Central

    Dean, Richard A.; Butler, Georgina S.; Hamma-Kourbali, Yamina; Delbé, Jean; Brigstock, David R.; Courty, José; Overall, Christopher M.

    2007-01-01

    Matrix metalloproteinases (MMPs) exert both pro- and antiangiogenic functions by the release of cytokines or proteolytically generated angiogenic inhibitors from extracellular matrix and basement membrane remodeling. In the Mmp2−/− mouse neovascularization is greatly reduced, but the mechanistic aspects of this remain unclear. Using isotope-coded affinity tag labeling of proteins analyzed by multidimensional liquid chromatography and tandem mass spectrometry we explored proteome differences between Mmp2−/− cells and those rescued by MMP-2 transfection. Proteome signatures that are hallmarks of proteolysis revealed cleavage of many known MMP-2 substrates in the cellular context. Proteomic evidence of MMP-2 processing of novel substrates was found. Insulin-like growth factor binding protein 6, follistatin-like 1, and cystatin C protein cleavage by MMP-2 was biochemically confirmed, and the cleavage sites in heparin affin regulatory peptide (HARP; pleiotrophin) and connective tissue growth factor (CTGF) were sequenced by matrix-assisted laser desorption ionization-time of flight mass spectrometry. MMP-2 processing of HARP and CTGF released vascular endothelial growth factor (VEGF) from angiogenic inhibitory complexes. The cleaved HARP N-terminal domain increased HARP-induced cell proliferation, whereas the HARP C-terminal domain was antagonistic and decreased cell proliferation and migration. Hence the unmasking of cytokines, such as VEGF, by metalloproteinase processing of their binding proteins is a new mechanism in the control of cytokine activation and angiogenesis. PMID:17908800

  9. Quantitative description of thermodynamic and kinetic properties of the platelet factor 4/heparin bonds

    NASA Astrophysics Data System (ADS)

    Nguyen, Thi-Huong; Greinacher, Andreas; Delcea, Mihaela

    2015-05-01

    Heparin is the most important antithrombotic drug in hospitals. It binds to the endogenous tetrameric protein platelet factor 4 (PF4) forming PF4/heparin complexes which may cause a severe immune-mediated adverse drug reaction, so-called heparin-induced thrombocytopenia (HIT). Although new heparin drugs have been synthesized to reduce such a risk, detailed bond dynamics of the PF4/heparin complexes have not been clearly understood. In this study, single molecule force spectroscopy (SMFS) is utilized to characterize the interaction of PF4 with heparins of defined length (5-, 6-, 8-, 12-, and 16-mers). Analysis of the force-distance curves shows that PF4/heparin binding strength rises with increasing heparin length. In addition, two binding pathways in the PF4/short heparins (<=8-mers) and three binding pathways in the PF4/long heparins (>=8-mers) are identified. We provide a model for the PF4/heparin complexes in which short heparins bind to one PF4 tetramer, while long heparins bind to two PF4 tetramers. We propose that the interaction between long heparins and PF4s is not only due to charge differences as generally assumed, but also due to hydrophobic interaction between two PF4s which are brought close to each other by long heparin. This complicated interaction induces PF4/heparin complexes more stable than other ligand-receptor interactions. Our results also reveal that the boundary between antigenic and non-antigenic heparins is between 8- and 12-mers. These observations are particularly important to understand processes in which PF4-heparin interactions are involved and to develop new heparin-derived drugs.Heparin is the most important antithrombotic drug in hospitals. It binds to the endogenous tetrameric protein platelet factor 4 (PF4) forming PF4/heparin complexes which may cause a severe immune-mediated adverse drug reaction, so-called heparin-induced thrombocytopenia (HIT). Although new heparin drugs have been synthesized to reduce such a risk, detailed

  10. Heparin inhibition of von Willebrand factor-dependent platelet function in vitro and in vivo.

    PubMed Central

    Sobel, M; McNeill, P M; Carlson, P L; Kermode, J C; Adelman, B; Conroy, R; Marques, D

    1991-01-01

    The intravenous administration of heparin to patients before open heart surgery reduced ristocetin cofactor activity by 58% (P less than 0.01, t test), and this impairment of von Willebrand factor-dependent platelet function was closely related to plasma heparin levels (r2 = 0.9), but not to plasma von Willebrand factor (vWF) levels. We hypothesized that heparin may inhibit vWF-dependent platelet hemostatic functions by directly binding vWF in solution and interfering with vWF-GpIb binding. Using the in vitro techniques of ristocetin-induced platelet agglutination, fluorescent flow cytometric measurement of vWF-platelet binding, and conventional radioligand binding assays we observed that heparin inhibited both vWF-dependent platelet function and vWF-platelet binding in a parallel and dose-dependent manner. Heparin also inhibited platelet agglutination induced by bovine vWF and inhibited the binding of human asialo-vWF to platelets in ristocetin-free systems. The inhibitory potency of heparin was not dependent upon its affinity for antithrombin III, but was molecular weight dependent: homogeneous preparations of lower molecular weight were less inhibitory. Heparin impairment of vWF function may explain why some hemorrhagic complications of heparin therapy are not predictable based on techniques for monitoring the conventional anticoagulant effects of heparin. PMID:2022745

  11. DEPENDENCE OF PPAR LIGAND-INDUCED MAPK SIGNALING ON EPIDERMAL GROWTH FACTOR RECEPTOR TRANSACTIVATION HEPARIN-BINDING EGF CLEAVAGE MEDIATES ZINC-INDUCED EGF RECEPTOR PHOSPHORYLATION

    EPA Science Inventory

    Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors that function as ligand-activated transcription factors regulating lipid metabolism and homeostasis. In addition to their ability to regulate PPAR-mediated gene transcription, PPARalpha and gamma li...

  12. Identification of heparin-binding EGF-like growth factor (HB-EGF) as a biomarker for lysophosphatidic acid receptor type 1 (LPA1) activation in human breast and prostate cancers.

    PubMed

    David, Marion; Sahay, Debashish; Mege, Florence; Descotes, Françoise; Leblanc, Raphaël; Ribeiro, Johnny; Clézardin, Philippe; Peyruchaud, Olivier

    2014-01-01

    Lysophosphatidic acid (LPA) is a natural bioactive lipid with growth factor-like functions due to activation of a series of six G protein-coupled receptors (LPA₁₋₆). LPA receptor type 1 (LPA₁) signaling influences the pathophysiology of many diseases including cancer, obesity, rheumatoid arthritis, as well as lung, liver and kidney fibrosis. Therefore, LPA₁ is an attractive therapeutic target. However, most mammalian cells co-express multiple LPA receptors whose co-activation impairs the validation of target inhibition in patients because of missing LPA receptor-specific biomarkers. LPA₁ is known to induce IL-6 and IL-8 secretion, as also do LPA₂ and LPA₃. In this work, we first determined the LPA induced early-gene expression profile in three unrelated human cancer cell lines expressing different patterns of LPA receptors (PC3: LPA₁,₂,₆; MDA-MB-231: LPA1,2; MCF-7: LPA₂,₆). Among the set of genes upregulated by LPA only in LPA₁-expressing cells, we validated by QPCR and ELISA that upregulation of heparin-binding EGF-like growth factor (HB-EGF) was inhibited by LPA₁-₃ antagonists (Ki16425, Debio0719). Upregulation and downregulation of HB-EGF mRNA was confirmed in vitro in human MDA-B02 breast cancer cells stably overexpressing LPA₁ (MDA-B02/LPA₁) and downregulated for LPA₁ (MDA-B02/shLPA1), respectively. At a clinical level, we quantified the expression of LPA₁ and HB-EGF by QPCR in primary tumors of a cohort of 234 breast cancer patients and found a significantly higher expression of HB-EGF in breast tumors expressing high levels of LPA₁. We also generated human xenograph prostate tumors in mice injected with PC3 cells and found that a five-day treatment with Ki16425 significantly decreased both HB-EGF mRNA expression at the primary tumor site and circulating human HB-EGF concentrations in serum. All together our results demonstrate that HB-EGF is a new and relevant biomarker with potentially high value in quantifying LPA

  13. Current structural biology of the heparin interactome.

    PubMed

    Pomin, Vitor H; Mulloy, Barbara

    2015-10-01

    Heparin is the best known therapeutically active carbohydrate. It can bind and regulate multiple functional proteins such as coagulation cofactors, chemokines, and growth factors. This versatility has led to the recently developed concept of the heparin interactome--a group of proteins that, as the name implies, interact with heparin. The heparin interactome is structurally and functionally diverse. Though natural ligands of this class of proteins may be any of the glycosaminoglycans however, their structural biology is generally studied using heparin as a model compound. NMR spectroscopy contributes significantly to structural investigations of the resultant complexes in solution. This review aims therefore at discussing the current status in structural biology of the molecular complexes formed between heparin and its protein partners through the current concept of the heparin interactome. PMID:26038285

  14. Endovascular Stents and Stent-Grafts: Is Heparin Coating Desirable?

    SciTech Connect

    Nelson, Stephen R.; Souza, Nandita M. de; Allison, David J.

    2000-07-15

    Heparins are glycosaminoglycans that, in addition to their anticoagulant activity, have interactions with growth factors and other glycoproteins. These interactions may stimulate neointimal hyperplasia when heparin is delivered locally on stents and stent-grafts. Modifying the structure of heparin to retain anticoagulant activity while minimizing these stimulatory effects on the vascular endothelium is desirable and may be achieved by understanding the relationships between the structure and function of the various parts of the heparin molecule.

  15. Harnessing endogenous growth factor activity modulates stem cell behavior

    PubMed Central

    Hudalla, Gregory A.; Kouris, Nicholas A.; Koepsel, Justin T.; Ogle, Brenda M.; Murphy, William L.

    2014-01-01

    The influence of specific serum-borne biomolecules (e.g. heparin) on growth factor-dependent cell behavior is often difficult to elucidate in traditional cell culture due to the random, non-specific nature of biomolecule adsorption from serum. We hypothesized that chemically well-defined cell culture substrates could be used to study the influence of sequestered heparin on human mesenchymal stem cell (hMSC) behavior. Specifically, we used bio-inert self-assembled monolayers (SAMs) chemically modified with a bioinspired heparin-binding peptide (termed “HEPpep”) and an integrin-binding peptide (RGDSP) as stem cell culture substrates. Our results demonstrate that purified heparin binds to HEPpep SAMs in a dose-dependent manner, and serum-borne heparin binds specifically and in a dose-dependent manner to HEPpep SAMs. These heparin-sequestering SAMs enhance hMSC proliferation by amplifying endogenous fibroblast growth factor (FGF) signaling, and enhance hMSC osteogenic differentiation by amplifying endogenous bone morphogenetic protein (BMP) signaling. The effects of heparin-sequestering are similar to the effects of supraphysiologic concentrations of recombinant FGF-2. hMSC phenotype is maintained over multiple population doublings on heparin-sequestering substrates in growth medium, while hMSC osteogenic differentiation is enhanced in a bone morphogenetic protein-dependent manner on the same substrates during culture in osteogenic induction medium. Together, these observations demonstrate that the influence of the substrate on stem cell phenotype is sensitive to the culture medium formulation. Our results also demonstrate that enhanced hMSC proliferation can be spatially localized by patterning the location of HEPpep on the substrate. Importantly, the use of chemically well-defined SAMs in this study eliminated the confounding factor of random, non-specific biomolecule adsorption, and identified serum-borne heparin as a key mediator of hMSC response to endogenous

  16. Detection and characterization of heparin-binding proteins with a gel overlay procedure

    SciTech Connect

    Mehlman, T.; Burgess, W.H. )

    1990-07-01

    The binding of {sup 125}I-labeled derivatives of heparin has been used by several investigators to identify heparin-binding fragments of different heparin-binding proteins. In this report we utilize the procedure described by J.W. Smith and D.J. Knauer (1987, Anal. Biochem. 160, 105-114) to produce {sup 125}I-fluorescein-heparin. Using this derivative, we compare the use of gel overlay procedures with Western blot procedures for the detection of heparin-binding proteins following polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. We show that the gel overlay procedure is a relatively simple and sensitive method for visualizing heparin-binding proteins. In addition, we use the procedure to characterize the heparin-binding properties of heparin-binding growth factor 1 (acidic fibroblast growth factor) with synthetic peptide competitors and site-directed mutants of the growth factor.

  17. Heparin coating of tantalum coronary stents reduces surface thrombin generation but not factor IXa generation.

    PubMed

    Blezer, R; Cahalan, L; Cahalan, P T; Lindhout, T

    1998-07-01

    In the present study we used an in-vitro technique to examine initiation and propagation of blood coagulation at the surface of tantalum coronary stents exposed to flowing platelet-rich and platelet-free plasma. The time course of factor IXa production at the surface of the stent was not influenced by platelets. In spite of a significant factor IXa production, no thrombin activity was detected when the tantalum stent was exposed to platelet-free plasma; only when the stent was exposed to platelet-rich plasma was extensive thrombin production observed. These findings indicate that tantalum triggers blood coagulation, but that (adherent) platelets are essential for thrombin generation. Heparin-coated tantalum stents exposed to flowing platelet-rich plasma showed that factor IXa generation was slightly reduced compared with the bare stent. However, the heparin coating drastically delayed the onset of thrombin generation and largely reduced the steady-state production of thrombin. We found a clear relationship between the antithrombin binding capacity and the antithrombogenic potential of the heparin-coated stents. The mode of action of immobilized heparin is thought to abrogate thrombin generation by inhibiting thrombin-dependent positive feedback reactions at the surface of the coronary stent. PMID:9712292

  18. Secretion by stimulated murine macrophages of a heparin-binding fibroblast growth activity, distinct from basic FGE and IL-1

    SciTech Connect

    Rappolee, D.A.; Banda, M.J.; Werb, Z.

    1986-03-01

    Wound healing requires granulation and formation of neovascularization tissue. These two events require increases in fibroblasts, vascular endothelial, and smooth muscle cells. Macrophages may produce several growth factors which participate in these would healing events. To test this hypothesis they have partially purified a fibroblast growth promoting activity from a murine macrophage cell line (P388 Dl). The activity causes growth in Balb/c and Swiss 3T3 cells as measured by thymidine uptake, nuclear labeling and increase in cell number. PDGF, Basic FGF, and EGF are also mitogenic by thymidine uptake, but purified human IL-1 and recombinant murine IL-1 are not. The activity is pH 2.5-, freeze/thaw-, and dialysis/lyphilyzation-stable. The activity elutes from heparin-Sepharose at 2.0M, but not 0.15m, 0.5M, or 3.0M NaCl. Basic FGF elutes from the same heparin-Sepharose batch at 3.0M, but not at the other three NaCl concentrations. The growth activity is secreted by viable murine macrophage line cells (P388D1, WEHI-3, RAW 264.7) at a 48 hour peak after activating (LPS) or phagocytic stimuli. Unstimulated P388D1 caused growth 1.7 times control whereas stimulation increases the growth 5.1 to 7.1 times control. The optimal activity concentration fails to complement insulin in an assay in which optimal basic FGF concentration complements insulin. These data suggest that the activity may contain a progression factor.

  19. Heparin-chitosan nanoparticle functionalization of porous poly(ethylene glycol) hydrogels for localized lentivirus delivery of angiogenic factors

    PubMed Central

    Thomas, Aline M.; Gomez, Andrew J.; Palma, Jaime L.; Yap, Woon Teck

    2014-01-01

    Hydrogels have been extensively used for regenerative medicine strategies given their tailorable mechanical and chemical properties. Gene delivery represents a promising strategy by which to enhance the bioactivity of the hydrogels, though the efficiency and localization of gene transfer have been challenging. Here, we functionalized porous poly(ethylene glycol) hydrogels with heparin-chitosan nanoparticles to retain the vectors locally and enhance lentivirus delivery while minimizing changes to hydrogel architecture and mechanical properties. The immobilization of nanoparticles, as compared to homogeneous heparin and/or chitosan, is essential to lentivirus immobilization and retention of activity. Using this gene-delivering platform, we over-expressed the angiogenic factors sonic hedgehog (Shh) and vascular endothelial growth factor (Vegf) to promote blood vessel recruitment to the implant site. Shh enhanced endothelial recruitment and blood vessel formation around the hydrogel compared to both Vegf-delivering and control hydrogels. The nanoparticle-modified porous hydrogels for delivering gene therapy vectors can provide a platform for numerous regenerative medicine applications. PMID:25023395

  20. Heparin binding to platelet factor-4. An NMR and site-directed mutagenesis study: arginine residues are crucial for binding.

    PubMed Central

    Mayo, K H; Ilyina, E; Roongta, V; Dundas, M; Joseph, J; Lai, C K; Maione, T; Daly, T J

    1995-01-01

    Native platelet factor-4 (PF4) is an asymmetrically associated, homo-tetrameric protein (70 residues/subunit) known for binding polysulphated glycosaminoglycans like heparin. PF4 N-terminal chimeric mutant M2 (PF4-M2), on the other hand, forms symmetric tetramers [Mayo, Roongta, Ilyina, Milius, Barker, Quinlan, La Rosa and Daly (1995) Biochemistry 34, 11399-11409] making NMR studies with this 32 kDa protein tractable. PF4-M2, moreover, binds heparin with a similar affinity to that of native PF4. NMR data presented here indicate that heparin (9000 Da cut-off) binding to PF4-M2, while not perturbing the overall structure of the protein, does perturb specific side-chain proton resonances which map to spatially related residues within a ring of positively charged side chains on the surface of tetrameric PF4-M2. Contrary to PF4-heparin binding models which centre around C-terminal alpha-helix lysines, this study indicates that a loop containing Arg-20, Arg-22, His-23 and Thr-25, as well as Lys-46 and Arg-49, are even more affected by heparin binding. Site-directed mutagenesis and heparin binding data support these NMR findings by indicating that arginines more than C-terminal lysines, are crucial to the heparin binding process. Images Figure 4 PMID:8526843

  1. In vivo studies on the binding of heparin and its fractions with platelet factor 4

    SciTech Connect

    Walz, D.A.; Hung, G.L.

    1985-01-01

    PF4 has a half-life in plasma of less than 3 minutes, and its rapid clearance appears to be a function of binding to the vascular endothelium. Once bound to the endothelium, PF4 can be released by heparin in a time-dependent manner; recovery is greater the sooner heparin is administered following PF4 infusion. This heparin-induced release of PF4 can be abolished if the heparin is first complexed with hexadimethrine bromide. Likewise, this heparin-induced release of PF4 is dependent upon the type of heparin used; low molecular weight heparin fractions and fragments do not cause the PF4 rebound seen with intact heparin. Thus, it would appear that low molecular weight forms of heparin are advantageous in that their in vivo administration would not be mediated by such platelet modulators as PF4.

  2. The Clinical Significance and Risk Factors of Anti-Platelet Factor 4/heparin Antibody on Maintenance Hemodialysis Patients: A Two-Year Prospective Follow-up

    PubMed Central

    Yao, Li; Lin, Hongli; Li, Jijun; Zhao, Jiuyang; Zhang, Zhimin; Lun, Lide; Zhang, Jianrong; Li, Mingxu; Huang, Qi; Yang, Yang; Jiang, Shimin; Wang, Yong; Zhu, Hanyu; Chen, Xiangmei

    2013-01-01

    Background Heparin-induced thrombocytopenia is an immune response mediated by anti-PF4/heparin antibody, which is clinically characterized by thrombocytopenia and thromboembolic events. In this study, a prospective and multi-center clinical investigation determined the positive rate of anti-PF4/heparin antibody in maintenance hemodialysis patients in China, identified the related risk factors, and further explored the effect of the anti-PF4/heparin antibody on bleeding, thromboembolic events, and risk of death in the patients. Methods The serum anti-PF4/heparin antibody was measured in 661 patients from nine hemodialysis centers, detected by IgG-specific ELISA and followed by confirmation with excess heparin. Risk factors of these patients were analyzed. Based on a two-year follow-up, the association between the anti-PF4/heparin antibody and bleeding, thromboembolic events, and risk of death in the patients was investigated. Results The positivity rate of the anti-PF4/heparin antibody in maintenance hemodialysis patients was 5.6%. With diabetes as an independent risk factor, the positivity rate of the anti-PF4/heparin antibody decreased in the patients undergoing weekly dialyses ≥3 times. The positivity rate of the anti-PF4/heparin antibody was not related to the occurrence of clinical thromboembolic events and was not a risk factor for death within two years in maintenance hemodialysis patients. Negativity for the anti-PF4/heparin antibody combined with a reduction of the platelet count or combined with the administration of antiplatelet drugs yielded a significant increase in bleeding events. However, the composite determination of the anti-PF4/heparin antibody and thrombocytopenia, as well as the administration of antiplatelet drugs, was not predictive for the risk of thromboembolic events in the maintenance hemodialysis patients. Conclusions A single detection of the anti-PF4/heparin antibody did not predict the occurrence of clinical bleeding, thromboembolic

  3. Oral heparins.

    PubMed

    Hiebert, Linda M

    2002-01-01

    The antithrombotic drug heparin is administered parenterally and believed not effective orally. Oral heparin would be most suitable for long term administration, often required for the prevention of thrombosis. Following parenteral administration, heparin is taken up by endothelial cells. Our laboratory has shown that heparin is similarly taken up by endothelium following oral administration, despite low plasma heparin concentrations. In a twenty-four hour period, endothelial heparin concentrations are greatest within 15 minutes of oral dosing although plasma levels never exceed one percent of dose. Endothelial uptake accounts for a considerable amount of absorption if the total body endothelium is considered. In support of oral heparin absorption, we demonstrated a dose-dependent decrease in thrombosis incidence in a rat jugular vein model following single oral doses of unfractionated heparins (bovine and porcine) or low molecular weight heparins (reviparin, logiparin and ardeparin). Low molecular weight heparins were effective at lower doses than unfractionated heparins where a fifty percent reduction in thrombosis was observed with 0.025 mg/kg reviparin, 0.1 mg/kg logiparin, versus 7.5 mg/kg bovine unfractionated heparin. These studies support the work of others demonstrating measurable systemic changes following oral heparin administration and suggest that heparin may be effective when administered by the oral route. It also indicates that the presence of heparin in plasma likely reflects a much greater amount associated with endothelium. PMID:11934211

  4. Bioengineered heparin

    PubMed Central

    Lord, Megan S; Whitelock, John M

    2014-01-01

    Heparin is a widely used drug for the control of blood coagulation. The majority of heparin that is produced commercially is derived from animal sources, is poly-disperse in nature and therefore ill-defined in structure. This makes regulation of heparin challenging with respect to identifying its absolute structural identity, purity, and efficacy. This raises the question as to whether there might be alternative methods of producing commercial grade heparin. The commentary highlights ways that we might manufacture heparin using bioengineering approaches to yield a successful therapeutic replacement for animal-derived heparin in the future. PMID:24902029

  5. Controlled release and gradient formation of human glial-cell derived neurotrophic factor from heparinated poly(ethylene glycol) microsphere-based scaffolds.

    PubMed

    Roam, Jacob L; Nguyen, Peter K; Elbert, Donald L

    2014-08-01

    Introduction of spatial patterning of proteins, while retaining activity and releasability, is critical for the field of regenerative medicine. Reversible binding to heparin, which many biological molecules exhibit, is one potential pathway to achieve this goal. We have covalently bound heparin to poly(ethylene glycol) (PEG) microspheres to create useful spatial patterns of glial-cell derived human neurotrophic factor (GDNF) in scaffolds to promote peripheral nerve regeneration. Labeled GDNF was incubated with heparinated microspheres that were subsequently centrifuged into cylindrical scaffolds in distinct layers containing different concentrations of GDNF. The GDNF was then allowed to diffuse out of the scaffold, and release was tracked via fluorescent scanning confocal microscopy. The measured release profile was compared to predicted Fickian models. Solutions of reaction-diffusion equations suggested the concentrations of GDNF in each discrete layer that would result in a nearly linear concentration gradient over much of the length of the scaffold. The agreement between the predicted and measured GDNF concentration gradients was high. Multilayer scaffolds with different amounts of heparin and GDNF and different crosslinking densities allow the design of a wide variety of gradients and release kinetics. Additionally, fabrication is much simpler and more robust than typical gradient-forming systems due to the low viscosity of the microsphere solutions compared to gelating solutions, which can easily result in premature gelation or the trapping of air bubbles with a nerve guidance conduit. The microsphere-based method provides a framework for producing specific growth factor gradients in conduits designed to enhance nerve regeneration. PMID:24816282

  6. Controlled Release and Gradient Formation of Human Glial-Cell Derived Neurotrophic Factor from Heparinated Poly(ethylene glycol) Microsphere-based Scaffolds

    PubMed Central

    Roam, Jacob L.; Nguyen, Peter K.; Elbert, Donald L.

    2014-01-01

    Introduction of spatial patterning of proteins, while retaining activity and releasability, is critical for the field of regenerative medicine. Reversible binding to heparin, which many biological molecules exhibit, is one potential pathway to achieving this goal. We have covalently bound heparin to poly(ethylene glycol) (PEG) microspheres to create useful spatial patterns of glial-cell derived human neurotrophic factor (GDNF) in scaffolds to promote peripheral nerve regeneration. Labeled GDNF was incubated with heparinated microspheres that were subsequently centrifuged into cylindrical scaffolds in distinct layers containing different concentrations of GDNF. The GDNF was then allowed to diffuse out of the scaffold, and release was tracked via fluorescent scanning confocal microscopy. The measured release profile was compared to predicted Fickian models. Solutions of reaction-diffusion equations suggested the concentrations of GDNF in each discrete layer that would result in a nearly linear concentration gradient over much of the length of the scaffold. The agreement between the predicted and measured GDNF concentration gradients was high. Multilayer scaffolds with different amounts of heparin and GDNF and different crosslinking densities allow the design of a wide variety of gradients and release kinetics. Additionally, fabrication is much simpler and more robust than typical gradient-forming systems due to the low viscosity of the microsphere solutions compared to gelating solutions, which can easily result in premature gelation or the trapping of air bubbles with a nerve guidance conduit. The microsphere-based method provides a framework for producing specific growth factor gradients in conduits designed to enhance nerve regeneration. PMID:24816282

  7. The Anti-Factor Xa Range For Low Molecular Weight Heparin Thromboprophylaxis

    PubMed Central

    Ward, Salena M.

    2015-01-01

    Low molecular weight heparins (LMWHs) are now the mainstay option in the prevention and treatment of venous thromboembolism. In some patients receiving therapeutic doses of LMWH, activity can be measured by quantifying the presence of Anti-factor Xa (AFXa) for dose adjustment. However, currently there are no guidelines for LMWH monitoring in patients on thromboprophylactic, doses, despite certain patient populations may be at risk of suboptimal dosing. This review found that while the AFXa ranges for therapeutic levels of LMWHs are relatively well defined in the literature, prophylactic ranges are much less clear, thus making it difficult to interpret current research data. From the studies published to date, we concluded that a reasonable AFXa target range for LMWH deep venous thromboses prophylaxis might be 0.2-0.5 IU/mL. PMID:26733269

  8. Covalent immobilization of stem cell inducing/recruiting factor and heparin on cell-free small-diameter vascular graft for accelerated in situ tissue regeneration.

    PubMed

    Shafiq, Muhammad; Jung, Youngmee; Kim, Soo Hyun

    2016-06-01

    The development of cell-free vascular grafts has tremendous potential for tissue engineering. However, thrombus formation, less-than-ideal cell infiltration, and a lack of growth potential limit the application of electrospun scaffolds for in situ tissue-engineered vasculature. To overcome these challenges, here we present development of an acellular tissue-engineered vessel based on electrospun poly(L-lactide-co-ɛ-caprolactone) scaffolds. Heparin was conjugated to suppress thrombogenic responses, and substance P (SP) was immobilized to recruit host cells. SP was released in a sustained manner from scaffolds and recruited human bone marrow-derived mesenchymal stem cells. The biocompatibility and biological performance of the grafts were evaluated by in vivo experiments involving subcutaneous scaffold implantation in Sprague-Dawley rats (n = 12) for up to 4 weeks. Histological analysis revealed a higher extent of accumulative host cell infiltration, neotissue formation, collagen deposition, and elastin deposition in scaffolds containing either SP or heparin/SP than in the control groups. We also observed the presence of a large number of laminin-positive blood vessels, von Willebrand factor (vWF(+) ) cells, and alpha smooth muscle actin-positive cells in the explants containing SP and heparin/SP. Additionally, SP and heparin/SP grafts showed the existence of CD90(+) and CD105(+) MSCs and induced a large number of M2 macrophages to infiltrate the graft wall compared with that observed with the control group. Our cell-free grafts could enhance vascular regeneration by endogenous cell recruitment and by mediating macrophage polarization into the M2 phenotype, suggesting that these constructs may be a promising cell-free graft candidate and are worthy of further in vivo evaluation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1352-1371, 2016. PMID:26822178

  9. Cultured human foreskin fibroblasts produce a factor that stimulates their growth with properties similar to basic fibroblast growth factor

    SciTech Connect

    Story, M.T. )

    1989-05-01

    To determine if fibroblasts could be a source of fibroblast growth factor (FGF) in tissue, cells were initiated in culture from newborn human foreskin. Fibroblast cell lysates promoted radiolabeled thymidine uptake by cultured quiescent fibroblasts. Seventy-nine percent of the growth-promoting activity of lysates was recovered from heparin-Sepharose. The heparin-binding growth factor reacted on immunoblots with antiserum to human placenta-derived basic FGF and competed with iodinated basic FGF for binding to antiserum to (1-24)bFGF synthetic peptide. To confirm that fibroblasts were the source of the growth factor, cell lysates were prepared from cells incubated with radiolabeled methionine. Heparin affinity purified material was immunoprecipitated with basic FGF antiserum and electrophoresed. Radiolabeled material was detected on gel autoradiographs in the same molecular weight region as authentic iodinated basic FGF. The findings are consistant with the notion that cultured fibroblasts express basic FGF. As these cells also respond to the mitogen, it is possible that the regulation of their growth is under autocrine control. Fibroblasts may be an important source of the growth factor in tissue.

  10. Induction of mast cell proliferation, maturation, and heparin synthesis by the rat c-kit ligand, stem cell factor

    SciTech Connect

    Tsai, M.; Takeishi, Takashi; Geissler, E.N. ); Thompson, H.; Metcalfe, D.D. ); Langley, K.E.; Zsebo, K.M.; Galli, S.J. )

    1991-07-15

    The authors investigated the effects of a newly recognized multifunctional growth factor, the c-kit ligand stem cell factor (SCF), on mouse mast cell proliferation and phenotype. Recombinant rat SCF{sup 164} (rrSCF{sup 164}) induced the development of large numbers of dermal mast cells in normal mice in vivo. Many of these mast cells had features of connective tissue-type mast cells (CTMC), in that they were reactive both with the heparin-binding fluorescent dye berberine sulfate and with safranin. In vitro, rrSCF{sup 164} induced the proliferation of cloned interleukin 3 (IL-3)-dependent mouse mast cells and primary populations of IL-3-dependent, bone marrow-derived cultured mast cells (BMCMC), which represent immature mast cells, and purified peritoneal mast cells, which represent a type of mature CTMC> BMCMC maintained in rrSCF{sup 164} not only proliferated but also matured. These findings identify SCF as a single cytokine that can induce immature, IL-3-dependent mast cells to mature and to acquire multiple characteristics of CTMC. These findings also directly demonstrate that SCF can regulate the development of a cellular lineage expressing c-kit through effects on both proliferation and maturation.

  11. Attachment of Flexible Heparin Chains to Gelatin Scaffolds Improves Endothelial Cell Infiltration

    PubMed Central

    Leijon, Jonas; Carlsson, Fredrik; Brännström, Johan; Sanchez, Javier; Larsson, Rolf; Nilsson, Bo; Rosenquist, Magnus

    2013-01-01

    Long-term survival of implanted cells requires oxygen and nutrients, the need for which is met by vascularization of the implant. The use of scaffolds with surface-attached heparin as anchoring points for angiogenic growth factors has been reported to improve this process. We examined the potential role of surface modification of gelatin scaffolds in promoting endothelial cell infiltration by using a unique macromolecular conjugate of heparin as a coating. Compared to other heparin coatings, this surface modification provides flexible heparin chains, representing a new concept in heparin conjugation. In vitro cell infiltration of scaffolds was assessed using a three-dimensional model in which the novel heparin surface, without growth factors, showed a 2.5-fold increase in the number of infiltrating endothelial cells when compared to control scaffolds. No additional improvement was achieved by adding growth factors (vascular endothelial growth factor and/or fibroblast growth factor-2) to the scaffold. In vivo experiments confirmed these results and also showed that the addition of angiogenic growth factors did not significantly increase the endothelial cell infiltration but increased the number of inflammatory cells in the implanted scaffolds. The endothelial cell-stimulating ability of the heparin surface alone, combined with its growth factor-binding capacity, renders it an interesting candidate surface treatment to create a prevascularized site prepared for implantation of cells and tissues, in particular those sensitive to inflammation but in need of supportive revascularization, such as pancreatic islets of Langerhans. PMID:23327585

  12. Heparin-induced thrombocytopenia.

    PubMed

    Brieger, D B; Mak, K H; Kottke-Marchant, K; Topol, E J

    1998-06-01

    Heparin-induced thrombocytopenia (HIT) is a potentially serious complication of heparin therapy and is being encountered more frequently in patients with cardiovascular disease as use of anticoagulant therapy becomes more widespread. Our understanding of the pathophysiology of this immune-mediated condition has improved in recent years, with heparin-platelet factor 4 complex as the culprit antigen in most patients. New sensitive laboratory assays for the pathogenic antibody are now available and should permit an earlier, more reliable diagnosis, but their optimal application remains to be defined. For patients in whom HIT is diagnosed, immediate discontinuation of heparin infusions and elimination of heparin from all flushes and ports are mandatory. Further management of patients with HIT is problematic at present, as there are no readily available alternative anticoagulant agents in the United States with proven efficacy in acute coronary disease. The direct thrombin inhibitors appear to be the most promising alternatives to heparin, when continued use of heparin is contraindicated, and the results of several multicenter trials evaluating their application in patients with HIT are awaited. PMID:9626819

  13. The Roles of Growth Factors in Keratinocyte Migration

    PubMed Central

    Seeger, Mark A.; Paller, Amy S.

    2015-01-01

    Significance: The re-epithelialization of wounded skin requires the rapid and coordinated migration of keratinocytes (KC) into the wound bed. Almost immediately after wounding, cells present at or attracted to the wound site begin to secrete a complex milieu of growth factors. These growth factors exert mitogenic and motogenic effects on KCs, inducing the rapid proliferation and migration of KCs at the wound edge. Recent Advances: New roles for growth factors in KC biology are currently being discovered and investigated. This review will highlight the growth factors, particularly transforming growth factor-α (TGF-α), heparin-binding epidermal growth factor (HB-EGF), insulin-like growth factor 1 (IGF-1), fibroblast growth factor 7 (FGF-7), FGF-10, and hepatocyte growth factor (HGF), which have conclusively been shown to be the most motogenic for KCs. Critical Issues: The cellular and molecular heterogeneity of wounded tissue makes establishing direct relationships between specific growth factors and KC migration difficult in situ. The absence of this complexity in simplified in vitro experimental models of migration makes the clinical relevance of the results obtained from these in vitro studies ambiguous. Future Directions: Deciphering the relationship between growth factors and KC migration is critical for understanding the process of wound healing in normal and disease states. Insights into the basic science of the effects of growth factors on KC migration will hopefully lead to the development of new therapies to treat acute and chronic wounds. PMID:25945284

  14. Growth factors for nanobacteria

    NASA Astrophysics Data System (ADS)

    Ciftcioglu, Neva; Kajander, E. Olavi

    1999-12-01

    Nanobacteria are novel microorganisms recently isolated from fetal bovine serum and blood of cows and humans. These coccoid, gram negative bacteria in alpha-2 subgroup of Proteobacteria grow slowly under mammalian cell culture conditions but not in common media for microbes. Now we have found two different kinds of culture supplement preparations that improve their growth and make them culturable in the classical sense. These are supernatant fractions of conditioned media obtained from 1 - 3 months old nanobacteria cultures and from about a 2 weeks old Bacillus species culture. Both improved multiplication and particle yields and the latter increased their resistance to gentamicin. Nanobacteria cultured with any of the methods shared similar immunological property, structure and protein pattern. The growth supporting factors were heat-stabile and nondialyzable, and dialysis improved the growth promoting action. Nanobacteria formed stony colonies in a bacteriological medium supplemented with the growth factors. This is an implication that nanobacterial growth is influenced by pre-existing bacterial flora.

  15. Vascular Endothelial Growth Factor is a Secreted Angiogenic Mitogen

    NASA Astrophysics Data System (ADS)

    Leung, David W.; Cachianes, George; Kuang, Wun-Jing; Goeddel, David V.; Ferrara, Napoleone

    1989-12-01

    Vascular endothelial growth factor (VEGF) was purified from media conditioned by bovine pituitary folliculostellate cells (FC). VEGF is a heparin-binding growth factor specific for vascular endothelial cells that is able to induce angiogenesis in vivo. Complementary DNA clones for bovine and human VEGF were isolated from cDNA libraries prepared from FC and HL60 leukemia cells, respectively. These cDNAs encode hydrophilic proteins with sequences related to those of the A and B chains of platelet-derived growth factor. DNA sequencing suggests the existence of several molecular species of VEGF. VEGFs are secreted proteins, in contrast to other endothelial cell mitogens such as acidic or basic fibroblast growth factors and platelet-derived endothelial cell growth factor. Human 293 cells transfected with an expression vector containing a bovine or human VEGF cDNA insert secrete an endothelial cell mitogen that behaves like native VEGF.

  16. New microbial growth factor

    NASA Technical Reports Server (NTRS)

    Bok, S. H.; Casida, L. E., Jr.

    1977-01-01

    A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

  17. Growth factors in haemopoiesis.

    PubMed

    Jones, A L; Millar, J L

    1989-01-01

    Haemopoietic growth factors have for over two decades allowed experimentalists to grow haemopoietic bone marrow cells in vitro. With refinements in technique and the discovery of novel growth factors, all of the known haemopoietic lineages can now be grown in vitro. This has allowed a much greater understanding of the complex process of haemopoiesis from the haemopoietic stem cell to the mature, functioning end-cell. The in vivo action of these growth factors has been harder to investigate. Although recombinant technology has afforded us the much greater quantities necessary for in vivo work, problems remain with administration because of effects on other tissues. Interpretation of results is difficult because of the complex inter-relationships which exist between factors. Some of these have been defined in vitro and it appears likely that they also operate in vivo. Erythropoietin is a physiological regulator of erythropoiesis. It has been detected in vivo with levels responding appropriately to stress (i.e. elevated in anaemia) and, when administered in pharmacological doses, has been shown to correct anaemia. Granulocyte/macrophage colony-stimulating factor (GM-CSF) has been detected in vivo and may influence the production and function of granulocytes and macrophages, although how it is regulated is unknown. Granulocyte colony-stimulating factor (G-CSF) and macrophage colony-stimulating factor are ore lineage-specific. Interleukin 3 (IL-3), although it has not been detected in vivo, may act on a primitive marrow precursor by expanding the population and making these cells more susceptible to other growth factors, such as GM-CSF. Interleukin 1 (IL-1) has been detected in vivo, does not appear to have any isolated action on bone marrow (except possibly radioprotection) but probably acts synergistically with other growth factors, such as G-CSF. Interleukins 2, 4, 5 and 6 have not been detected in vivo. All have effects on B-cells. In addition IL-2 is an essential

  18. Peptide growth factors, part B

    SciTech Connect

    Barnes, D.; Sirbasku, D.A.

    1987-01-01

    This book discusses the following topics: Platelet-Derived Growth Factor;Nerve and Glial Growth Factors;PC12 Pheochromocytoma Cells;Techniques for the Study of Growth Factor Activity;Genetic Approaches and Biological Effects.

  19. Array-based functional screening of heparin glycans.

    PubMed

    Puvirajesinghe, Tania M; Ahmed, Yassir A; Powell, Andrew K; Fernig, David G; Guimond, Scott E; Turnbull, Jeremy E

    2012-05-25

    Array methodologies have become powerful tools for interrogation of glycan-protein interactions but have critically lacked the ability to generate cell response data. Here, we report the development of a slide-based array method exemplified by measurement of activation of fibroblast growth factor signaling by heparin saccharides. Heparan sulfate-deficient Swiss 3T3 cells were overlaid onto an aminosilane-coated slide surface onto which heparin saccharides had been spotted and immobilized. The cells were transiently stimulated with FGF2 and immunofluorescence measured to assess downstream ERK1/2 phosphorylation. Activation of this signaling pathway response was restricted to cells exposed to heparin saccharides competent to activate FGF2 signaling. Differential activation of the overlaid cells by different-sized heparin saccharides was demonstrated by quantitative measurement of fluorescence intensity. This "glycobioarray" platform has significant potential as a generic tool for functional glycomics screening. PMID:22633407

  20. The suppression of fibroblast growth factor 2/fibroblast growth factor 4-dependent tumour angiogenesis and growth by the anti-growth factor activity of dextran derivative (CMDB7).

    PubMed Central

    Bagheri-Yarmand, R.; Kourbali, Y.; Mabilat, C.; Morère, J. F.; Martin, A.; Lu, H.; Soria, C.; Jozefonvicz, J.; Crépin, M.

    1998-01-01

    Our previous studies showed that carboxymethyl benzylamide dextran (CMDB7) blocks basic fibroblast growth factor (FGF-2)-dependent cell proliferation of a human breast epithelial line (HBL100), suggesting its potential role as a potent antiangiogenic substance. The derived cell line (HH9), which was transformed with the hst/FGF4 gene, has been shown to be highly proliferative in vitro and to induce angiogenic tumours in nude mice. We show here that CMDB7 inhibits the mitogenic activities of the conditioned media from HBL 100 and HH9 cells in a dose-dependent manner. When HH9 cells were injected s.c. into nude mice, CMDB7 treatment (300 mg kg(-1) week(-1)) suppressed the tumour take and the tumour growth by about 50% and 80% respectively. Immunohistochemical analysis showed a highly significant decrease, by more than threefold, in the endothelial density of viable tumour regions, together with a significant increase in the necrosis area. This antiangiogenic activity of CMDB7 was further demonstrated by direct inhibition of calf pulmonary artery (CPAE) and human umbilical vein (HUVEC) endothelial cell proliferation and migration in vitro. In addition, we showed that CMDB7 inhibits specifically the mitogenic effects of the growth factors that bind to heparin such as FGF-2, FGF-4, platelet-derived growth factor (PDGF-BB) and transforming growth factor (TGF-beta1), but not those of epidermal growth factor (EGF) and insulin-like growth factor (IGF-1). These results demonstrate that CMDB7 inhibits FGF-2/FGF-4-dependent tumour growth and angiogenesis, most likely by disrupting the autocrine and paracrine effects of growth factors released from the tumour cells. Images Figure 4 PMID:9662260

  1. Mode of heparin attachment to nanocrystalline hydroxyapatite affects its interaction with bone morphogenetic protein-2.

    PubMed

    Goonasekera, Chandhi S; Jack, Kevin S; Bhakta, Gajadhar; Rai, Bina; Luong-Van, Emma; Nurcombe, Victor; Cool, Simon M; Cooper-White, Justin J; Grøndahl, Lisbeth

    2015-01-01

    Heparin has a high affinity for bone morphogenetic protein-2 (BMP-2), which is a key growth factor in bone regeneration. The aim of this study was to investigate how the rate of release of BMP-2 was affected when adsorbed to nanosized hydroxyapatite (HAP) particles functionalized with heparin by different methods. Heparin was attached to the surface of HAP, either via adsorption or covalent coupling, via a 3-aminopropyltriethoxysilane (APTES) layer. The chemical composition of the particles was evaluated using X-ray photoelectron spectroscopy and elemental microanalysis, revealing that the heparin grafting densities achieved were dependent on the curing temperature used in the fabrication of APTES-modified HAP. Comparable amounts of heparin were attached via both covalent coupling and adsorption to the APTES-modified particles, but characterization of the particle surfaces by zeta potential and Brunauer-Emmett-Teller measurements indicated that the conformation of the heparin on the surface was dependent on the method of attachment, which in turn affected the stability of heparin on the surface. The release of BMP-2 from the particles after 7 days in phosphate-buffered saline found that 31% of the loaded BMP-2 was released from the APTES-modified particles with heparin covalently attached, compared to 16% from the APTES-modified particles with the heparin adsorbed. Moreover, when heparin was adsorbed onto pure HAP, it was found that the BMP-2 released after 7 days was 5% (similar to that from unmodified HAP). This illustrates that by altering the mode of attachment of heparin to HAP the release profile and total release of BMP-2 can be manipulated. Importantly, the BMP-2 released from all the heparin particle types was found by the SMAD 1/5/8 phosphorylation assay to be biologically active. PMID:26474791

  2. Pluripotency transcription factor Sox2 is strongly adsorbed by heparin but requires a protein transduction domain for cell internalization

    SciTech Connect

    Albayrak, Cem; Yang, William C.; Swartz, James R.

    2013-02-15

    Highlights: ► Both R9Sox2 and Sox2 bind heparin with comparable affinity. ► Both R9Sox2 and Sox2 bind to fibroblasts, but only R9Sox2 is internalized. ► Internalization efficiency of R9Sox2 is 0.3% of the administered protein. ► Heparan sulfate adsorption may be part of a mechanism for managing cell death. -- Abstract: The binding of protein transduction domain (PTD)-conjugated proteins to heparan sulfate is an important step in cellular internalization of macromolecules. Here, we studied the pluripotency transcription factor Sox2, with or without the nonaarginine (R9) PTD. Unexpectedly, we observed that Sox2 is strongly adsorbed by heparin and by the fibroblasts without the R9 PTD. However, only the R9Sox2 fusion protein is internalized by the cells. These results collectively show that binding to heparan sulfate is not sufficient for cellular uptake, thereby supporting a recent hypothesis that other proteins play a role in cell internalization of PTD-conjugated proteins.

  3. Heparin-functionalized polymeric biomaterials in tissue engineering and drug delivery applications

    PubMed Central

    Liang, Yingkai; Kiick, Kristi L.

    2014-01-01

    Heparin plays an important role in many biological processes, via its interaction with various proteins, and hydrogels and nanoparticles comprising heparin exhibit attractive properties such as anticoagulant activity, growth factor binding, as well as antiangiogenic and apoptotic effects, making them great candidates for emerging applications. Accordingly, this review summarizes recent efforts in the preparation of heparin-based hydrogels and formation of nanoparticles, as well as the characterization of their properties and applications. The challenges and future perspectives for heparin-based materials are also discussed. Prospects are promising for heparin-containing polymeric biomaterials in diverse applications ranging from cell carriers for promoting cell differentiation to nanoparticle therapeutics for cancer treatment. PMID:23911941

  4. Heparin Microparticle Effects on Presentation and Bioactivity of Bone Morphogenetic Protein-2

    PubMed Central

    Hettiaratchi, Marian H.; Miller, Tobias; Temenoff, Johnna S.; Guldberg, Robert E.; McDevitt, Todd C.

    2014-01-01

    Biomaterials capable of providing localized and sustained presentation of bioactive proteins are critical for effective therapeutic growth factor delivery. However, current biomaterial delivery vehicles commonly suffer from limitations that can result in low retention of growth factors at the site of interest or adversely affect growth factor bioactivity. Heparin, a highly sulfated glycosaminoglycan, is an attractive growth factor delivery vehicle due to its ability to reversibly bind positively charged proteins, provide sustained delivery, and maintain protein bioactivity. This study describes the fabrication and characterization of heparin methacrylamide (HMAm) microparticles for recombinant growth factor delivery. HMAm microparticles were shown to efficiently bind several heparin-binding growth factors (e.g. bone morphogenetic protein-2 (BMP-2), vascular endothelial growth factor (VEGF), and basic fibroblast growth factor (FGF-2)), including a wide range of BMP-2 concentrations that exceeds the maximum binding capacity of other common growth factor delivery vehicles, such as gelatin. BMP-2 bioactivity was assessed on the basis of alkaline phosphatase (ALP) activity induced in skeletal myoblasts (C2C12). Microparticles loaded with BMP-2 stimulated comparable C2C12 ALP activity to soluble BMP-2 treatment, indicating that BMP-2-loaded microparticles retain bioactivity and potently elicit a functional cell response. In summary, our results suggest that heparin microparticles stably retain large amounts of bioactive BMP-2 for prolonged periods of time, and that presentation of BMP-2 via heparin microparticles can elicit cell responses comparable to soluble BMP-2 treatment. Consequently, heparin microparticles present an effective method of delivering and spatially retaining growth factors that could be used in a variety of systems to enable directed induction of cell fates and tissue regeneration. PMID:24881028

  5. Click-coated, heparinized, decellularized vascular grafts

    PubMed Central

    Dimitrievska, Sashka; Cai, Chao; Weyers, Amanda; Balestrini, Jenna L.; Lin, Tylee; Sundaram, Sumati; Hatachi, Go; Spiegel, David A.; Kyriakides, Themis R.; Miao, Jianjun; Li, Guoyun; Niklason, Laura; Linhardt, Robert J.

    2014-01-01

    A novel method enabling the engineering of a dense and appropriately oriented heparin-containing layer on decellularized aortas has been developed. Amino groups of decellularized aortas were first modified to azido groups using 3-azidobenzoic acid. Azide-clickable dendrons were attached onto the azido groups through “alkyne-azide” click chemistry, affording a ten-fold amplification of adhesions sites. Dendron end groups were finally decorated with end-on modified heparin chains. Heparin chains were oriented like heparan sulfate groups on native endothelial cells surface. XPS, NMR, MS and FTIR were used to characterize the synthesis steps, building the final heparin layered coatings. Continuity of the heparin coating was verified using fluorescent microscopy and histological analysis. Efficacy of heparin linkage was demonstrated with factor Xa antithrombogenic assay and platelet adhesion studies. The results suggest that oriented heparin immobilization to decellularized aortas may improve the in vivo blood compatibility of decellularized aortas and vessels. PMID:25463496

  6. Dimerization Capacities of FGF2 Purified with or without Heparin-Affinity Chromatography

    PubMed Central

    Chiu, Liang-Yuan; Taouji, Said; Moroni, Elisabetta; Colombo, Giorgio; Chevet, Eric; Sue, Shih-Che; Bikfalvi, Andreas

    2014-01-01

    Fibroblast growth factor-2 (FGF2) is a pleiotropic growth factor exhibiting a variety of biological activities. In this article, we studied the capacity of FGF2 purified with or without heparin affinity chromatography to self-associate. Analyzing the NMR HSQC spectra for different FGF2 concentrations, heparin-affinity purified FGF2 showed perturbations that indicate dimerization and are a higher-order oligomerization state. HSQC perturbation observed with different FGF2 concentrations revealed a heparin-binding site and two dimer interfaces. Thus, with increasing protein concentrations, FGF2 monomers make contacts with each other and form dimers or higher order oligomers. On the contrary, FGF2 purified with ion-exchange chromatography did not show similar perturbation indicating that self-association of FGF2 is eliminated if purification is done without heparin-affinity chromatography. The HSQC spectra of heparin-affinity purified FGF2 can be reproduced to some extent by adding heparin tetra-saccharide to ion exchange chromatography purified FGF2. Heparin-affinity purified FGF2 bound to acceptor and donor beads in a tagged form using His-tagged or GST-tagged proteins, also dimerized in the AlphaScreen™ assay. This assay was further validated using different experimental conditions and competitors. The assay constitutes an interesting tool to study dimerization of other FGF forms as well. PMID:25299071

  7. The effects of angiogenic growth factors on extravillous trophoblast invasion and motility.

    PubMed

    Lash, G E; Cartwright, J E; Whitley, G S; Trew, A J; Baker, P N

    1999-11-01

    There is accumulating evidence that deficient trophoblast invasion of the placental bed spiral arteries is crucial to the pathogenesis of pre-eclampsia and intrauterine growth restriction. However, the factors which regulate the process of trophoblast invasion remain unclear. We have investigated whether extravillous trophoblast invasion and motility are mediated by the angiogenic growth factors, vascular endothelial growth factor (VEGF) and placental growth factor (PlGF). The SGHPL-4 extravillous trophoblast cell line was utilized. Expression of mRNA for the receptors of VEGF and PlGF (KDR and flt-1) was determined using the reverse transcriptase polymerase chain reaction. An in vitro model of invasion assessed the number and length of trophoblast processes invading into an extracellular matrix. The motility of cells under standard culture conditions was also quantified. The effect of the addition of VEGF and PlGF (+/-heparin) on trophoblast invasion and motility was determined. The effect of VEGF and PlGF (+/-heparin) on SGHPL-4 cell proliferation was assessed by cell counts at 24, 48 and 72 h post-addition of growth factor. The SGHPL-4 cells expressed mRNA for the flt-1 but not the KDR receptor. The addition of VEGF resulted in a significant decrease in the number of trophoblast processes formed (P< 0.02); this effect was not influenced by the addition of heparin. However, there was no effect on the length of processes formed in response to VEGF (+/-heparin). The addition of PlGF had no effect on either the number or the length of processes formed. The addition of VEGF increased the motility of the SGHPL-4 cells (P< 0.002); the addition of heparin prevented this VEGF-induced increase in motility. The addition of PlGF had no effect on SGHPL-4 motility (+/-heparin). Neither growth factor had any effect on the proliferative ability of SGHPL-4 cells. Contrary to our hypothesis, we did not find that the angiogenic growth factors, VEGF and PlGF, mediated the in vitro

  8. Binding Potency of Heparin Immobilized on Activated Charcoal for DNA Antibodies.

    PubMed

    Snezhkova, E A; Tridon, A; Evrard, B; Nikolaev, V G; Uvarov, V Yu; Tsimbalyuk, R S; Ivanuk, A A; Komov, V V; Sakhno, L A

    2016-02-01

    In vitro experiments showed that heparin adsorbed on activated charcoal can bind antibodies raised against native and single-stranded DNA in a diluted sera pool with a high level of these DNA. Thus, heparin used as anticoagulant during hemosorption procedure can demonstrate supplementary therapeutic activity resulting from its interaction with various agents involved in acute and chronic inflammatory reactions such as DNA- and RNA-binding substances, proinflammatory cytokines, complement components, growth factors, etc. Research and development of heparin-containing carbonic adsorbents for the therapy of numerous inflammatory and autoimmune diseases seems to be a promising avenue in hematology. PMID:26902353

  9. Growth hormone, growth factors, and acromegaly

    SciTech Connect

    Ludecke, D.K.; Tolis, G.T.

    1987-01-01

    This book contains five sections, each consisting of several papers. The section headings are: Biochemistry and Physiology of GH and Growth Factors, Pathology of Acromegaly, Clinical Endocrinology of Acromegaly, Nonsurgical Therapy of Acromegaly, and Surgical Therapy of Acromegaly.

  10. Synthesis and structural study of two new heparin-like hexasaccharides.

    PubMed

    Lucas, Ricardo; Angulo, Jesús; Nieto, Pedro M; Martín-Lomas, Manuel

    2003-07-01

    Two new heparin-like hexasaccharides, 5 and 6, have been synthesised using a convergent block strategy and their solution conformations have been determined by NMR spectroscopy and molecular modelling. Both hexasaccharides contain the basic structural motif of the regular region of heparin but with negative charge distributions which have been designed to get insight into the mechanism of fibroblast growth factors (FGFs) activation. PMID:12945695

  11. Measuring Anti–Factor Xa Activity to Monitor Low-Molecular-Weight Heparin in Obesity: A Critical Review

    PubMed Central

    Egan, Gregory; Ensom, Mary H H

    2015-01-01

    Background: The choice of whether to monitor anti–factor Xa (anti-Xa) activity in patients who are obese and who are receiving low-molecular-weight heparin (LMWH) therapy is controversial. To the authors’ knowledge, no systematic review of monitoring of anti-Xa activity in such patients has been published to date. Objective: To systematically ascertain the utility of monitoring anti-Xa concentrations for LMWH therapy in obese patients. Data Sources: MEDLINE (1946 to September 2014), the Cochrane Database of Systematic Reviews, Embase (1974 to September 2014), PubMed (1947 to September 2014), International Pharmaceutical Abstracts (1970 to September 2014), and Scopus were searched using the terms obesity, morbid obesity, thrombosis, venous thrombosis, embolism, venous thromboembolism, pulmonary embolism, low-molecular weight heparin, enoxaparin, dalteparin, tinzaparin, anti-factor Xa, anti-factor Xa monitoring, anti-factor Xa activity, and anti-factor Xa assay. The reference lists of retrieved articles were also reviewed. Study Selection and Data Extraction: English-language studies describing obese patients treated with LMWH or reporting anti-Xa activity were reviewed using a 9-step decision-making algorithm to determine whether monitoring of LMWH therapy by means of anti-Xa activity in obesity is warranted. Studies published in abstract form were excluded. Data Synthesis: The analysis showed that anti-Xa concentrations are not strongly associated with thrombosis or hemorrhage. In clinical studies of LMWH for thromboprophylaxis in bariatric surgery, orthopedic surgery, general surgery, and medical patients, and for treatment of venous thrombo embolism and acute coronary syndrome, anti-Xa activity can be predicted from dose of LMWH and total body weight; no difference in clinical outcome was found between obese and non-obese participants. Conclusions: Routinely determining anti-Xa concentrations in obese patients to monitor the clinical effectiveness of LMWH is

  12. Comparison of Low-Molecular-Weight Heparins Prepared From Bovine Lung Heparin and Porcine Intestine Heparin.

    PubMed

    Guan, Yudong; Xu, Xiaohui; Liu, Xinyue; Sheng, Anran; Jin, Lan; Linhardt, Robert J; Chi, Lianli

    2016-06-01

    Currently porcine intestine is the only approved source for producing pharmaceutical heparin in most countries. Enoxaparin, prepared by benzylation and alkaline depolymerization from porcine intestine heparin, is prevalent in the anticoagulant drug market. It is predicted that porcine intestine heparin-derived enoxaparin (PIE) will encounter shortage, and expanding its production from heparins obtained from other animal tissues may, therefore, be inevitable. Bovine lung heparin is a potential alternative source for producing enoxaparin. Critical processing parameters for producing bovine lung heparin-derived enoxaparin (BLE) are discussed. Three batches of BLEs were prepared and their detailed structures were compared with PIEs using modern analytical techniques, including disaccharide composition, intact chain mapping by liquid chromatography-mass spectrometry and 2-dimensional nuclear magnetic resonance spectroscopy. The results suggested that the differences between PIEs and BLEs mainly result from N-acetylation differences derived from the parent heparins. In addition, bioactivities of BLEs were about 70% of PIEs based on anti-factor IIa and Xa chromogenic assays. We conclude that BLE has the potential to be developed as an analogue of PIE, although some challenges still remain. PMID:27238483

  13. Deep vein thrombosis, ecythyma gangrenosum and heparin-induced thrombocytopenia occurring in a man with a heterozygous Factor V Leiden mutation

    PubMed Central

    Apostolova, Mariya; Weng, Baoying; Pote, Harry H.; Ashcraft, Harold; Goldblatt, Curtis; Woolley, Paul V.

    2012-01-01

    Skin necrosis and limb gangrene are occasional thrombotic manifestations of anticoagulation therapy. We report a man heterozygous for the Factor V Leiden (FVL) mutation, and with a history of recurrent deep venous thrombosis, who initially presented with a necrotic skin lesion of the right flank while on warfarin therapy with a therapeutic international normalized ratio. Warfarin was discontinued and he received intravenous heparin. Thereafter he developed thrombocytopenia and pedal erythema and was diagnosed with heparin-induced thrombocytopenia (HIT). Heparin was replaced with argatroban. He ultimately underwent bilateral below-knee amputations for the thrombotic complications of the HIT. The initial necrotic lesion healed with antibiotics and wound care. Pathologic examination of multiple biopsy specimens revealed two separate lesions. One was necrotic tissue infiltrated with methicillin resistant Staphylococcus aureus having features of ecthyma gangrenosum. The second showed thrombotic changes consistent with HIT. The case illustrates the differential diagnosis of skin necrosis and limb gangrene in patients on warfarin and heparin, and also the clinical complexities that can occur in a FVL heterozygote. PMID:23355938

  14. Molecular Insights into the Klotho-Dependent, Endocrine Mode of Action of Fibroblast Growth Factor 19 Subfamily Members

    SciTech Connect

    Goetz,R.; Beenken, A.; Ibrahimi, O.; Kalinina, J.; Olsen, S.; Eliseenkova, A.; Xu, C.; Neubert, T.; Zhang, F.; et al.

    2007-01-01

    Unique among fibroblast growth factors (FGFs), FGF19, -21, and -23 act in an endocrine fashion to regulate energy, bile acid, glucose, lipid, phosphate, and vitamin D homeostasis. These FGFs require the presence of Klotho/{beta}Klotho in their target tissues. Here, we present the crystal structures of FGF19 alone and FGF23 in complex with sucrose octasulfate, a disaccharide chemically related to heparin. The conformation of the heparin-binding region between {beta} strands 10 and 12 in FGF19 and FGF23 diverges completely from the common conformation adopted by paracrine-acting FGFs. A cleft between this region and the {beta}1-{beta}2 loop, the other heparin-binding region, precludes direct interaction between heparin/heparan sulfate and backbone atoms of FGF19/23. This reduces the heparin-binding affinity of these ligands and confers endocrine function. Klotho/{beta}Klotho have evolved as a compensatory mechanism for the poor ability of heparin/heparan sulfate to promote binding of FGF19, -21, and -23 to their cognate receptors.

  15. Heparin fragments inhibit human vascular smooth muscle cell proliferation in vitro

    SciTech Connect

    Selden, S.C.; Johnson, W.V.; Maciag, T.

    1986-03-01

    The authors have examined the effect of heparin on human abdominal aortic smooth muscle cell growth. Cell proliferation was inhibited by more than 90% at a concentration of 20 ..mu..g/ml in a 12 day growth assay using heparin from Sigma, Upjohn or Calbiochem. Additionally, 200 ..mu..g/ml Upjohn heparin inhibits /sup 3/H-thymidine incorporation by 50% in short term assays using serum or purified platelet-derived growth factor (25-100ng/ml) to initiate the cell cycle. Homogeneous size classes of heparin fragments were prepared by nitrous acid cleavage and BioGel P-10 filtration chromatography. Deca-, octa-, hexa-, tetra-, and di-saccharides inhibited proliferation by 90% at concentrations of 280, 320, 260, 180 and 100 ..mu..g/ml, respectively, in a 12 day growth assay. These data confirm the work of Castellot et.al. and extend the range of inhibitory fragments down to the tetra- and di-saccharide size. These data suggest, therefore, that di-saccharide subunit of heparin is sufficient to inhibit vascular smooth muscle cell proliferation. The authors are now examining the role of the anhydromannose moiety on the reducing end of the nitrous acid generated fragments as a possible mediator of heparin-induced inhibition of vascular smooth muscle cell proliferation.

  16. Local Effect of Heparin Binding Neurotrophic Factor Combined With Chitosan Entubulization on Sciatic Nerve Repair in Rats

    PubMed Central

    Mehrshad, Ali; Seddighnia, Ashkan; Shadabi, Mohammadreza; Najafpour, Alireza; Mohammadi, Rahim

    2016-01-01

    Objective: To assess the effect of on sciatic nerve regeneration in animal model of rat. Methods: Seventy-five male Wistar rats were divided into five experimental groups randomly (each group containing 15 animals): Sham operation group (SHAM), autograft group (AUTO), transected control (TC), chitosan conduit (CHIT) and heparin binding neurotrophic factor treated group (CHIT/HBNF). In AUTO group a segment of sciatic nerve was transected and reimplanted reversely. In SHAM group sciatic nerve was exposed and manipulated. In transected group left sciatic nerve was transected and stumps were fixed in adjacent muscle (TC). In treatment group defect was bridged using a chitosan conduit (CHIT) filled with 10 µL HBNF (CHIT/HBNF). Each group was subdivided into four subgroups of five animals each and nerve fibers were studied in a 12-week period. Results: Behavioral, functional, biomechanical, electrophysiological and gastrocnemius muscle mass findings and morphometric indices confirmed faster recovery of regenerated axons in treatment group than in CHIT group (P=0.001). Immunohistochemical reactions to S-100 in treatment group were more positive than that in CHIT group. Conclusion: Local administration of improved functional recovery and morphometric indices of sciatic nerve. It could be considered as an effective treatment for peripheral nerve repair in practice. PMID:27331064

  17. Injectable gelatin derivative hydrogels with sustained vascular endothelial growth factor release for induced angiogenesis.

    PubMed

    Li, Zhe; Qu, Tiejun; Ding, Chen; Ma, Chi; Sun, Hongchen; Li, Shirong; Liu, Xiaohua

    2015-02-01

    Injectable biomaterials are attractive for soft tissue regeneration because they are handled in a minimally invasive manner and can easily adapt to complex defects. However, inadequate vascularization of the injectable constructs has long been a barrier, leading to necrosis or volume reduction after implantation. In this work, we developed a three-step process to synthesize injectable gelatin-derived hydrogels that are capable of controlling growth factor delivery to induce angiogenesis. In our approach, tyramine was first introduced into gelatin chains to provide enzymatic crosslinking points for gel formation after injection. Next, heparin, a polysaccharide with binding domains to many growth factors, was covalently linked to the tyramine-modified gelatin. Finally, vascular endothelial growth factor (VEGF) was incorporated into the gelatin derivative by binding with the heparin in the gelatin derivative, and an injectable gel with controlled VEGF release was formed by an enzymatic catalytic reaction with hydrogen peroxide (H2O2) and horseradish peroxidase (HRP). The gelation time, mechanical properties and degradation of the gel was readily tailored by the gelatin concentration and the ratio of H2O2/HRP. Binding VEGF to heparin stabilizes this growth factor, protects it from denaturation and proteolytic degradation and subsequently prolongs the sustained release. An in vitro release study and bioactivity assay indicated that the VEGF was released in a sustained manner with high bioactivity for over 3 weeks. Furthermore, a chicken chorioallantoic membrane (CAM) assay and animal experiments were performed to evaluate in vivo bioactivity of the VEGF released from the hydrogels. After 5 days of incubation on CAM, the number of blood vessels surrounding the heparin-modified hydrogels was increased by 2.4-fold compared with that of the control group. Deeper and denser cell infiltration and angiogenesis in the heparin-modified gelatin/VEGF gels were observed compared to

  18. Injectable gelatin derivative hydrogels with sustained vascular endothelial growth factor release for induced angiogenesis

    PubMed Central

    Li, Zhe; Qu, Tiejun; Ding, Chen; Ma, Chi; Sun, Hongchen; Li, Shirong; Liu, Xiaohua

    2014-01-01

    Injectable biomaterials are attractive for soft tissue regeneration because they are handled in a minimally invasive manner and can easily adapt to complex defects. However, inadequate vascularization of the injectable constructs has long been a barrier, leading to necrosis or volume reduction after implantation. In this work, we developed a three-step process to synthesize injectable gelatin-derived hydrogels that are capable of controlling growth factor delivery to induce angiogenesis. In our approach, tyramine was first introduced into gelatin chains to provide enzymatical crosslinking points for gel formation after injection. Next, heparin, a polysaccharide with binding domains to many growth factors, was covalently linked to the tyramine-modified gelatin. Finally, vascular endothelial growth factor (VEGF) was incorporated into the gelatin derivative by binding with the heparin in the gelatin derivative, and an injectable gel with controlled VEGF release was formed by an enzymatic catalytic reaction with hydrogen peroxide (H2O2) and horseradish peroxidase (HRP). The gelation time, mechanical properties and degradation of the gel was readily tailored by the gelatin concentration and the ratio of H2O2/HRP. Binding VEGF to heparin stabilizes this growth factor, protects it from denaturation and proteolytic degradation, and subsequently prolongs the sustained release. An in vitro release study and bioactivity assay indicated that the VEGF was released in a sustained manner with high bioactivity for over 3 weeks. Furthermore, a chicken chorioallantoic membrane (CAM) assay and animal experiments were performed to evaluate in vivo bioactivity of the VEGF released from the hydrogels. After 5 days of incubation on CAM, the number of blood vessels surrounding the heparin-modified hydrogels was 2.4-fold increase than that of the control group. Deeper and denser cell infiltration and angiogenesis in the heparin-modified gelatin/VEGF gels were observed than in the controls

  19. Oral heparin results in the appearance of heparin fragments in the plasma of rats

    SciTech Connect

    Larsen, A.K.; Lund, D.P.; Langer, R.; Folkman, J.

    1986-05-01

    We have previously shown that angiogenesis inhibition and tumor regression can be accomplished by combinations of heparin or heparin fragments with cortisone. Oral heparin was also effective in combination with cortisone. We now show that a single oral dose of (/sup 35/S)heparin or (/sup 3/H)heparin (15,000 units/kg) results in continuous release of radioactive material into the bloodstream for at least 12 hr. This is associated with the presence of anti-factor Xa activity at a level of approximately equal to 0.1 unit/ml. The radioactive material is identified as oligo-, di-, and monosaccharides by its behavior in chromatographic systems, its possession of anti-factor Xa activity, and the effect of treatment with bacterial heparinase. The heparin fragments are extensively metabolized to fragments without anti-factor Xa activity that are readily subject to urinary excretion.

  20. Structural Basis for Antagonism by Suramin of Heparin Binding to Vaccinia Complement Protein

    SciTech Connect

    Ganesh, Vannakambadi K.; Muthuvel, Suresh Kumar; Smith, Scott A.; Kotwal, Girish J.; Murthy, Krishna H.M.

    2010-07-19

    Suramin is a competitive inhibitor of heparin binding to many proteins, including viral envelope proteins, protein tyrosine phosphatases, and fibroblast growth factors (FGFs). It has been clinically evaluated as a potential therapeutic in treatment of cancers caused by unregulated angiogenesis, triggered by FGFs. Although it has shown clinical promise in treatment of several cancers, suramin has many undesirable side effects. There is currently no experimental structure that reveals the molecular interactions responsible for suramin inhibition of heparin binding, which could be of potential use in structure-assisted design of improved analogues of suramin. We report the structure of suramin, in complex with the heparin-binding site of vaccinia virus complement control protein (VCP), which interacts with heparin in a geometrically similar manner to many FGFs. The larger than anticipated flexibility of suramin manifested in this structure, and other details of VCP-suramin interactions, might provide useful structural information for interpreting interactions of suramin with many proteins.

  1. Structural and Functional Basis of CXCL12 (stromal cell-derived factor-1 alpha) Binding to Heparin

    SciTech Connect

    Murphy,J.; Cho, Y.; Sachpatzidis, A.; Fan, C.; Hodsdon, M.; Lolis, E.

    2007-01-01

    CXCL12 (SDF-1a) and CXCR4 are critical for embryonic development and cellular migration in adults. These proteins are involved in HIV-1 infection, cancer metastasis, and WHIM disease. Sequestration and presentation of CXCL12 to CXCR4 by glycosaminoglycans (GAGs) is proposed to be important for receptor activation. Mutagenesis has identified CXCL12 residues that bind to heparin. However, the molecular details of this interaction have not yet been determined. Here we demonstrate that soluble heparin and heparan sulfate negatively affect CXCL12-mediated in vitro chemotaxis. We also show that a cluster of basic residues in the dimer interface is required for chemotaxis and is a target for inhibition by heparin. We present structural evidence for binding of an unsaturated heparin disaccharide to CXCL12 attained through solution NMR spectroscopy and x-ray crystallography. Increasing concentrations of the disaccharide altered the two-dimensional 1H-15N-HSQC spectra of CXCL12, which identified two clusters of residues. One cluster corresponds to {beta}-strands in the dimer interface. The second includes the amino-terminal loop and the a-helix. In the x-ray structure two unsaturated disaccharides are present. One is in the dimer interface with direct contacts between residues His25, Lys27, and Arg41 of CXCL12 and the heparin disaccharide. The second disaccharide contacts Ala20, Arg21, Asn30, and Lys64. This is the first x-ray structure of a CXC class chemokine in complex with glycosaminoglycans. Based on the observation of two heparin binding sites, we propose a mechanism in which GAGs bind around CXCL12 dimers as they sequester and present CXCL12 to CXCR4.

  2. Cell number and chondrogenesis in human mesenchymal stem cell aggregates is affected by the sulfation level of heparin used as a cell coating.

    PubMed

    Lei, Jennifer; Trevino, Elda; Temenoff, Johnna

    2016-07-01

    For particular cell-based therapies, it may be required to culture mesenchymal stem cell (MSC) aggregates with growth factors to promote cell proliferation and/or differentiation. Heparin, a negatively charged glycosaminoglycan (GAG) is known to play an important role in sequestration of positively charged growth factors and, when incorporated within cellular aggregates, could be used to promote local availability of growth factors. We have developed a heparin-based cell coating and we believe that the electrostatic interaction between native heparin and the positively charged growth factors will result in (1) higher cell number in response to fibroblast growth factor-2 (FGF-2) and 2) greater chondrogenic differentiation in response to transforming growth factor-β1 (TGF-β1), compared to a desulfated heparin coating. Results revealed that in the presence of FGF-2, by day 14, heparin-coated MSC aggregates increased in DNA content 8.5 ± 1.6 fold compared to day 1, which was greater than noncoated and desulfated heparin-coated aggregates. In contrast, when cultured in the presence of TGF-β1, by day 21, desulfated heparin-coated aggregates upregulated gene expression of collagen II by 86.5 ± 7.5 fold and collagen X by 37.1 ± 4.7 fold, which was higher than that recorded in the noncoated and heparin-coated aggregates. These observations indicate that this coating technology represents a versatile platform to design MSC culture systems with pairings of GAGs and growth factors that can be tailored to overcome specific challenges in scale-up and culture for MSC-based therapeutics. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1817-1829, 2016. PMID:26990913

  3. Interstitial fibrosis and growth factors.

    PubMed Central

    Lasky, J A; Brody, A R

    2000-01-01

    Interstitial pulmonary fibrosis (IPF) is scarring of the lung caused by a variety of inhaled agents including mineral particles, organic dusts, and oxidant gases. The disease afflicts millions of individuals worldwide, and there are no effective therapeutic approaches. A major reason for this lack of useful treatments is that few of the molecular mechanisms of disease have been defined sufficiently to design appropriate targets for therapy. Our laboratory has focused on the molecular mechanisms through which three selected peptide growth factors could play a role in the development of IPF. Hundreds of growth factors and cytokines could be involved in the complex disease process. We are studying platelet-derived growth factor because it is the most potent mesenchymal cell mitogen yet described, transforming growth factor beta because it is a powerful inducer of extracellular matrix (scar tissue) components by mesenchymal cells, and tumor necrosis factor alpha because it is a pleiotropic cytokine that we and others have shown is essential for the development of IPF in animal models. This review describes some of the evidence from studies in humans, in animal models, and in vitro, that supports the growth factor hypothesis. The use of modern molecular and transgenic technologies could elucidate those targets that will allow effective therapeutic approaches. Images Figure 1 Figure 2 PMID:10931794

  4. Growth factors in ischemic stroke

    PubMed Central

    Lanfranconi, S; Locatelli, F; Corti, S; Candelise, L; Comi, G P; Baron, P L; Strazzer, S; Bresolin, N; Bersano, A

    2011-01-01

    Abstract Data from pre-clinical and clinical studies provide evidence that colony-stimulating factors (CSFs) and other growth factors (GFs) can improve stroke outcome by reducing stroke damage through their anti-apoptotic and anti-inflammatory effects, and by promoting angiogenesis and neurogenesis. This review provides a critical and up-to-date literature review on CSF use in stroke. We searched for experimental and clinical studies on haemopoietic GFs such as granulocyte CSF, erythropoietin, granulocyte-macrophage colony-stimulating factor, stem cell factor (SCF), vascular endothelial GF, stromal cell-derived factor-1α and SCF in ischemic stroke. We also considered studies on insulin-like growth factor-1 and neurotrophins. Despite promising results from animal models, the lack of data in human beings hampers efficacy assessments of GFs on stroke outcome. We provide a comprehensive and critical view of the present knowledge about GFs and stroke, and an overview of ongoing and future prospects. PMID:20015202

  5. Total synthesis of biotinylated N domain of human hepatocyte growth factor.

    PubMed

    Raibaut, Laurent; Vicogne, Jérome; Leclercq, Bérénice; Drobecq, Hervé; Desmet, Rémi; Melnyk, Oleg

    2013-06-15

    Hepatocyte growth factor/scatter factor (HGF/SF) is the high affinity ligand of MET tyrosine kinase receptor. We report here the total synthesis of a biotinylated analogue of human HGF/SF N domain. Functionally, N domain is part of the HGF/SF high affinity binding site for MET and also the main HGF/SF binding site for heparin. The 97 Aa linear chain featuring a C-terminal biotin group was assembled in high yield using an N-to-C one-pot three segments assembly strategy relying on a sequential Native Chemical Ligation (NCL)/bis(2-sulfanylethyl)amido (SEA) native peptide ligation process. The folded protein displayed the native disulfide bond pattern and showed the ability to bind heparin. PMID:23523386

  6. Dynamic properties of biologically active synthetic heparin-like hexasaccharides.

    PubMed

    Angulo, Jesús; Hricovíni, Milos; Gairi, Margarida; Guerrini, Marco; de Paz, José Luis; Ojeda, Rafael; Martín-Lomas, Manuel; Nieto, Pedro M

    2005-10-01

    A complete study of the dynamics of two synthetic heparin-like hexasaccharides, D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (1) and -->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHAc-6-SO4-alpha-(1-->4)-L-IdoA-alpha-(1-->4)-D-GlcNHSO3-alpha-(1-->4)-L-IdoA-2-SO4-alpha-1-->iPr (2), has been performed using 13C-nuclear magnetic resonance (NMR) relaxation parameters, T1, T2, and heteronuclear nuclear Overhauser effect (NOEs). Compound 1 is constituted from sequences corresponding to the major polysaccharide heparin region, while compound 2 contains a sequence never found in natural heparin. They differ from each other only in sulphation patterns, and are capable of stimulating fibroblast growth factors (FGFs)-1 induced mitogenesis. Both oligosaccharides exhibit a remarkable anisotropic overall motion in solution as revealed by their anisotropic ratios (tau /tau||), 4.0 and 3.0 respectively. This is a characteristic behaviour of natural glycosaminoglycans (GAG) which has also been observed for the antithrombin (AT) binding pentasaccharide D-GlcNHSO3-6-SO4-alpha-(1-->4)-D-GlcA-beta-(1-->4)-D-GlcNHSO3-(3,6-SO4)-alpha-(1-->4)-L-IdoA-2-SO4-alpha-(1-->4)-D-GlcNHSO3-6-SO4-alpha-1-->Me (3) (Hricovíni, M., Guerrini, M., Torri, G., Piani, S., and Ungarelli, F. (1995) Conformational analysis of heparin epoxide in aqueous solution. An NMR relaxation study. Carbohydr. Res., 277, 11-23). The motional properties observed for 1 and 2 provide additional support to the suitability of these compounds as heparin models in agreement with previous structural (de Paz, J.L., Angulo, J., Lassaletta, J.M., Nieto, P.M., Redondo-Horcajo, M., Lozano, R.M., Jiménez-Gallego, G., and Martín-Lomas, M. (2001) The activation of fibroblast growth factors by heparin: synthesis, structure and biological activity of heparin-like oligosaccharides. Chembiochem, 2, 673-685; Ojeda, R

  7. Biology of FGFRL1, the fifth fibroblast growth factor receptor.

    PubMed

    Trueb, Beat

    2011-03-01

    FGFRL1 (fibroblast growth factor receptor like 1) is the most recently discovered member of the FGFR family. It contains three extracellular Ig-like domains similar to the classical FGFRs, but it lacks the protein tyrosine kinase domain and instead contains a short intracellular tail with a peculiar histidine-rich motif. The gene for FGFRL1 is found in all metazoans from sea anemone to mammals. FGFRL1 binds to FGF ligands and heparin with high affinity. It exerts a negative effect on cell proliferation, but a positive effect on cell differentiation. Mice with a targeted deletion of the Fgfrl1 gene die perinatally due to alterations in their diaphragm. These mice also show bilateral kidney agenesis, suggesting an essential role for Fgfrl1 in kidney development. A human patient with a frameshift mutation exhibits craniosynostosis, arguing for an additional role of FGFRL1 during bone formation. FGFRL1 contributes to the complexity of the FGF signaling system. PMID:21080029

  8. Gelatin/chitosan/hyaluronan ternary complex scaffold containing basic fibroblast growth factor for cartilage tissue engineering.

    PubMed

    Tan, Huaping; Gong, Yihong; Lao, Lihong; Mao, Zhengwei; Gao, Changyou

    2007-10-01

    Gelatin, chitosan and hyaluronan with a weight ratio of 82.6%, 16.5% and 0.1% were chosen as a scaffold material to mimic the composition of natural cartilage matrix for cartilage tissue engineering. Water soluble carbodiimide was added into the biomacromolecule solution with a concentration of 5% to crosslink the complex. Following a freeze-drying procedure, a porous scaffold (control) was then prepared. To enhance chondrogenesis, heparin was covalently immobilized onto the scaffold by carbodiimide chemistry, through which basic fibroblast growth factor (bFGF) was further incorporated by a bioaffinity force. Incubation in phosphate buffered saline (PBS, pH 7.4) at 37 degrees C caused the weight loss of all kinds of the scaffolds, which could be brought by both the degradation and dissolution of the biomacromolecules. Compared with the control, however, the heparinized scaffold showed stronger ability to resist the weight loss, implying that a higher crosslinking degree was achieved by incorporation of the heparin. Rabbit auricular chondrocytes were seeded onto the ternary complex scaffold containing bFGF to assess cell response. Chondrocytes could adhere and proliferate in all kinds of the scaffold, regardless of the existence of bFGF. No significant difference on glycosaminoglycan (GAG) secretion was recorded between these scaffolds after cultured for 7 and 21 days too, although the absolute value from the Scaffold-heparin-bFGF was somewhat higher. However, chondrocytes seeded in the Scaffold-heparin-bFGF indeed showed significant higher viability than that on the control scaffold. These results reveal that the ternary complex scaffolds, in particular the one containing bFGF, are a potential candidate for cartilage tissue engineering. PMID:17554603

  9. Stabilization of somatropin by heparin.

    PubMed

    Zamiri, Camellia; Groves, Michael J

    2005-05-01

    Somatropin, human growth hormone (hGH), is an unstable protein, posing challenging problems for its formulation and long-term stability. Since hGH formed insoluble adducts with heparin our aim was to evaluate heparin as a stabilizing agent for the drug. These adducts were characterized by particle diameter, tertiary structure variations and release studies. Studies were also carried out to determine the stability of hGH in the presence and absence of heparin by an interfacial denaturation method and real-time stability studies by measuring hGH activity and particle diameter. Moreover, biological activity of hGH and hGH/UH (unfractionated heparin) adducts was identified by daily subcutaneous injections to hypophysectomized rats. There was a decrease in mean hydrodynamic particle diameter of hGH/UH adducts with increased pH (54.4 to 12.2 nm from pH 3 to pH 7) indicating that the adducts were either dissociating or dissolving at high pH. Furthermore, second-derivative spectroscopy indicated that complexation of hGH with heparin did not cause a major disruption in the tertiary structure of hGH but decreased the hydrophilic environment around the tyrosine residues. Release of hGH from hGH/UH adducts was pH and ionic strength dependent with the highest release at pH 8 (93%) and lowest release at pH 3 (0%) over the first hour. Interfacial denaturation methods indicated that vortex agitation over 120 s resulted in no change in the optical density of hGH/UH adducts compared with a substantial increase for hGH alone at pH 6.8. Real-time stability studies over 93 days demonstrated that hGH/UH adducts at both pH 3 and 7 with an excess of heparin produced the highest percent of active hGH remaining in the solution at 4 degrees C and 37 degrees C. The higher stability of hGH/UH adducts with excess heparin compared with the stoichiometric ratio was also confirmed by particle size measurements during storage. The biological activity of these adducts was comparable with hGH alone

  10. Growth factor identity is encoded by discrete coiled coil rotamers in the EGFR juxtamembrane region

    PubMed Central

    Doerner, Amy; Scheck, Rebecca; Schepartz, Alanna

    2015-01-01

    Summary Binding of the growth factor TGF-α to the EGFR extracellular domain is encoded through the formation of a unique anti-parallel coiled coil within the juxtamembrane segment. This new coiled coil is an ‘inside-out’ version of the coiled coil formed in the presence of EGF. A third, intermediary coiled coil interface is formed in the juxtamembrane segment when EGFR is stimulated with betacellulin. The seven growth factors that activate EGFR in mammalian systems (EGF, TGF-α, epigen, epiregulin, betacellulin, heparin-binding EGF, and amphiregulin) fall into distinct categories in which the structure of the coiled coil induced within the juxtamembrane segment correlates with cell state. The observation that coiled coil state tracks with the downstream signaling profiles for each ligand provides evidence for growth factor functional selectivity by EGFR. Encoding growth factor identity in alternative coiled coil rotamers provides a simple and elegant method for communicating chemical information across the plasma membrane. PMID:26091170

  11. Analyses of Interactions Between Heparin and the Apical Surface Proteins of Plasmodium falciparum

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kyousuke; Takano, Ryo; Takemae, Hitoshi; Sugi, Tatsuki; Ishiwa, Akiko; Gong, Haiyan; Recuenco, Frances C.; Iwanaga, Tatsuya; Horimoto, Taisuke; Akashi, Hiroomi; Kato, Kentaro

    2013-11-01

    Heparin, a sulfated glycoconjugate, reportedly inhibits the blood-stage growth of the malaria parasite Plasmodium falciparum. Elucidation of the inhibitory mechanism is valuable for developing novel invasion-blocking treatments based on heparin. Merozoite surface protein 1 has been reported as a candidate target of heparin; however, to better understand the molecular mechanisms involved, we characterized the molecules that bind to heparin during merozoite invasion. Here, we show that heparin binds only at the apical tip of the merozoite surface and that multiple heparin-binding proteins localize preferentially in the apical organelles. To identify heparin-binding proteins, parasite proteins were fractionated by means of heparin affinity chromatography and subjected to immunoblot analysis with ligand-specific antibodies. All tested members of the Duffy and reticulocyte binding-like families bound to heparin with diverse affinities. These findings suggest that heparin masks the apical surface of merozoites and blocks interaction with the erythrocyte membrane after initial attachment.

  12. Hepatoma-derived growth factor stimulates smooth muscle cell growth and is expressed in vascular development

    PubMed Central

    Everett, Allen D.; Lobe, David R.; Matsumura, Martin E.; Nakamura, Hideji; McNamara, Coleen A.

    2000-01-01

    Hepatoma-derived growth factor (HDGF) is the first member identified of a new family of secreted heparin-binding growth factors highly expressed in the fetal aorta. The biologic role of HDGF in vascular growth is unknown. Here, we demonstrate that HDGF mRNA is expressed in smooth muscle cells (SMCs), most prominently in proliferating SMCs, 8–24 hours after serum stimulation. Exogenous HDGF and endogenous overexpression of HDGF stimulated a significant increase in SMC number and DNA synthesis. Rat aortic SMCs transfected with a hemagglutinin-epitope–tagged rat HDGF cDNA contain HA-HDGF in their nuclei during S-phase. We also detected native HDGF in nuclei of cultured SMCs, of SMCs and endothelial cells from 19-day fetal (but not in the adult) rat aorta, of SMCs proximal to abdominal aortic constriction in adult rats, and of SMCs in the neointima formed after endothelial denudation of the rat common carotid artery. Moreover, HDGF colocalizes with the proliferating cell nuclear antigen (PCNA) in SMCs in human atherosclerotic carotid arteries, suggesting that HDGF helps regulate SMC growth during development and in response to vascular injury. PMID:10712428

  13. Growth factors in orthopedic surgery

    PubMed Central

    Zaharia, C; Despa, N; Simionescu, M; Jinga, V; Fleseriu, I

    2010-01-01

    Growth factors have represented an essential issue of interest for the researchers and clinicians in orthopedics and trauma over the last 40 years. In the last 10 to 15 years, the advances registered in this field have permitted the identification of the most active cellular and humoral factors as well as the improvement of their use in the orthopedic and trauma surgery. Their domain of application has been continuously enlarged and the results have been visible from the beginning. The authors present their appreciation on the actual state of this subject as well as their experience with results and related conclusions. PMID:20302195

  14. Heparin-induced conformational changes of fibronectin within the extracellular matrix promote hMSC osteogenic differentiation.

    PubMed

    Li, Bojun; Lin, Zhe; Mitsi, Maria; Zhang, Yang; Vogel, Viola

    2015-01-01

    An increasing body of evidence suggests important roles of extracellular matrix (ECM) in regulating stem cell fate. This knowledge can be exploited in tissue engineering applications for the design of ECM scaffolds appropriate to direct stem cell differentiation. By probing the conformation of fibronectin (Fn) using fluorescence resonance energy transfer (FRET), we show here that heparin treatment of the fibroblast-derived ECM scaffolds resulted in more extended conformations of fibrillar Fn in ECM. Since heparin is a highly negatively charged molecule while fibronectin contains segments of positively charged modules, including FnIII13, electrostatic interactions between Fn and heparin might interfere with residual quaternary structure in relaxed fibronectin fibers thereby opening up buried sites. The conformation of modules FnIII12-14 in particular, which contain one of the heparin binding sites as well as binding sites for many growth factors, may be activated by heparin, resulting in alterations in growth factor binding to Fn. Indeed, upregulated osteogenic differentiation was observed when hMSCs were seeded on ECM scaffolds that had been treated with heparin and were subsequently chemically fixed. In contrast, either rigidifying relaxed fibers by fixation alone, or heparin treatment without fixation had no effect. We hypothesize that fibronectin's conformations within the ECM are activated by heparin such as to coordinate with other factors to upregulate hMSC osteogenic differentiation. Thus, the conformational changes of fibronectin within the ECM could serve as a 'converter' to tune hMSC differentiation in extracellular matrices. This knowledge could also be exploited to promote osteogenic stem cell differentiation on biomedical surfaces. PMID:26214191

  15. Enhanced Survival and Engraftment of Transplanted Stem Cells using Growth Factor Sequestering Hydrogels

    PubMed Central

    Jha, Amit K.; Tharp, Kevin M.; Ye, Jianqin; Santiago-Ortiz, Jorge L.; Jackson, Wesley M.; Stahl, Andreas; Schaffer, David V.; Yeghiazarians, Yerem; Healy, Kevin E.

    2015-01-01

    We have generated a bioinspired tunable system of hyaluronic acid (HyA)-based hydrogels for Matrix-Assisted Cell Transplantation (MACT). With this material, we have independently evaluated matrix parameters such as adhesion peptide density, mechanical properties, and growth factor sequestering capacity, to engineer an environment that imbues donor cells with a milieu that promotes survival and engraftment with host tissues after transplantation. Using a versatile population of Sca-1+/CD45− cardiac progenitor cells (CPCs), we demonstrated that the addition of heparin in the HyA hydrogels was necessary to coordinate the presentation of TGFβ1 and to support the trophic functions of the CPCs via endothelial cell differentiation and vascular like tubular network formation. Presentation of exogenous TGFβ1 by binding with heparin improved differentiated CPC function by sequestering additional endogenously-produced angiogenic factors. Finally, we demonstrated that TGFβ1 and heparin-containing HyA hydrogels can promote CPC survival when implanted subcutaneously into murine hind-limbs and encouraged their participation in the ensuing neovascular response, including blood vessels that had anastomosed with the host’s blood vessels. PMID:25682155

  16. Transforming growth factor-beta 1 and fibroblast growth factors in rat growth plate.

    PubMed

    Jingushi, S; Scully, S P; Joyce, M E; Sugioka, Y; Bolander, M E

    1995-09-01

    Chondrocytes in the growth plate progress in an orderly fashion from resting through proliferating to hypertrophic cells. In the region of hypertrophic chondrocytes, the cartilage is invaded by capillary loops and endochondral ossification is initiated. It is currently believed that growth factors may regulate the proliferation and maturation of chondrocytes and the synthesis of extracellular matrix in the growth plate. The ordered sequence of proliferation and differentiation observed in the growth plate provides a unique opportunity to study the role of acidic fibroblast growth factor, basic fibroblast growth factor, and transforming growth factor-beta 1 in the regulation of these processes. In this study, expression of the mRNA of these growth factors was examined using total RNA extracted from the physis and epiphysis of rat tibias. Transforming growth factor-beta 1 mRNA was detected by Northern hybridization. Expression of the genes encoding acidic and basic fibroblast growth factors was demonstrated by polymerase chain reaction amplification. In addition, using polyclonal antibodies against these growth factors, we localized them by immunohistochemical analysis. Strong intracellular staining with a predominantly nuclear pattern was observed in chondrocytes from the proliferating and upper hypertrophic zones. In contrast, chondrocytes in the resting zone stained only faintly for the presence of these growth factors. Some chondrocytes in the resting zone adjacent to the proliferating zone stained with these antibodies, and the antibodies also stained cells in the zone of Ranvier, which regulates latitudinal bone growth. Lastly, the location of transforming growth factor-beta 1 was examined further with use of a polyclonal antipeptide antibody specific for its extracellular epitope.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7472755

  17. BIODEGRADABLE PHOTO-CROSSLINKED ALGINATE NANOFIBRE SCAFFOLDS WITH TUNEABLE PHYSICAL PROPERTIES, CELL ADHESIVITY AND GROWTH FACTOR RELEASE

    PubMed Central

    Jeong, Sung In; Jeon, Oju; Krebs, Melissa D.; Hill, Michael C.; Alsberg, Eben

    2012-01-01

    Nanofibrous scaffolds are of interest in tissue engineering due to their high surface area to volume ratio, interconnected pores, and architectural similarity to the native extracellular matrix. Our laboratory recently developed a biodegradable, photo-crosslinkable alginate biopolymer. Here, we show the capacity of the material to be electrospun into a nanofibrous matrix, and the ability to enhance cell adhesion and proliferation on these matrices by covalent modification with cell adhesion peptides. Additionally, the potential of covalently incorporating heparin into the hydrogels during the photopolymerisation process to sustain the release of a heparin binding growth factor via affinity interactions was demonstrated. Electrospun photo-crosslinkable alginate nanofibrous scaffolds endowed with cell adhesion ligands and controlled delivery of growth factors may allow for improved regulation of cell behaviour for regenerative medicine. PMID:23070945

  18. A role for the perlecan protein core in the activation of the keratinocyte growth factor receptor.

    PubMed Central

    Ghiselli, G; Eichstetter, I; Iozzo, R V

    2001-01-01

    Perlecan, a widespread heparan sulphate (HS) proteoglycan, is directly involved in the storing of angiogenic growth factors, mostly members of the fibroblast growth factor (FGF) gene family. We have previously shown that antisense targeting of the perlecan gene causes a reduced growth and responsiveness to FGF7 [also known as keratinocyte growth factor (KGF)] in human cancer cells, and that the perlecan protein core interacts specifically with FGF7. In the present paper, we have investigated human colon carcinoma cells in which the perlecan gene was disrupted by targeted homologous recombination. After screening over 1000 clones, we obtained two clones heterozygous for the null mutation with no detectable perlecan, indicating that the other allele was non-functioning. The perlecan-deficient cells grew more slowly, did not respond to FGF7 with or without the addition of heparin, and were less tumorigenic than control cells. Paradoxically, the perlecan-deficient cells displayed increased FGF7 surface binding. However, the perlecan protein core was required for functional activation of the KGF receptor and downstream signalling. Because heparin could not substitute for perlecan, the HS chains are not critical for FGF7-mediated signalling in this cell system. These results provide the first genetic evidence that the perlecan protein core is a molecular entity implicated in FGF7 binding and activation of its receptor. PMID:11563979

  19. Epidermal growth factor and growth in vivo

    SciTech Connect

    Rhodes, J.A.

    1986-01-01

    Epidermal growth factor (EGF) causes a dose-dependent thickening of the epidermis in suckling mice. The cellular mechanisms underlying this thickening were analyzed by measuring the effect of EGF on the cell-cycle. Neonatal mice were given daily injections of either 2ug EGF/g body weight/day or an equivalent volume of saline, and on the seventh day received a single injection of /sup 3/H-thymidine. At various times the mice were perfused with fixative; 1um sections of skin were stained with a modification of Harris' hematoxylin and were autoradiographed. The sections were analyzed using three methods based on the dependence on time after injection of /sup 3/H-thymidine of: frequency of labelled mitoses, labelling index, and reciprocal grains/nucleus. It was found that EGF caused a two-fold increase in the cell production rate. The effect of exogenous EGF on the morphology of gastric mucosa and incisors of suckling mice was also studied. The gastric mucosa appeared thicker in EGF-treated animals, but the effect was not statistically significant. In contrast to its effect on epidermis and gastric mucosa, EGF caused a significant, dose-dependent decrease in the size of the incisors. Because the mouse submandibular salivary gland is the major source of EGF the effect of sialoadenectomy on female reproductive functions was examined. Ablation of the submandibular gland had no effect on: length of estrus cycle, ability of the female to produce litters, length of the gestation period, litter size, and weight of the litter at birth. There was also no effect on survival of the offspring or on age at which the eyelids separated.

  20. Heparin-binding peptide amphiphile supramolecular architectures as platforms for angiogenesis and drug delivery

    NASA Astrophysics Data System (ADS)

    Chow, Lesleyann W.

    A fascinating phenomenon in nature is the self-assembly of molecules into a functional, hierarchical structure. In the past decade, the Stupp Laboratory has developed several classes of self-assembling biomaterials, one of which is the synthetic peptide amphiphile (PA). Self-assembling PAs are attractive and versatile biomolecules that can be customized for specific applications in regenerative medicine. In particular, a heparin-binding peptide amphiphile (HBPA) containing a specific heparin-binding peptide sequence was used here to induce angiogenesis and serve as a delivery vehicle for growth factors and small hydrophobic molecules. Throughout this dissertation, the HBPA/heparin system is used in different architectures for a variety of regenerative medicine applications. In one aspect of this work, hybrid scaffolds made from HBPA/heparin gelled on a poly(L-lactic acid) (PLLA) fiber mesh were used to promote angiogenesis to facilitate pancreatic islet transplantation for the treatment of type 1 diabetes. Delivery of growth factors with HBPA/PLLA scafflolds increased vessel density in vivo and correlated with improved transplant outcomes in a streptozotocin-induced diabetic mouse model. Soluble HBPA nanofiber architectures were also useful for islet transplantation applications. These nanofibers were used at concentrations below gelation to deliver growth factors into the dense islet cell aggregate, promoting cell survival and angiogenesis in vitro. The nanostructures infiltrated the islets and promoted the retention of heparin and growth factors within the islet. Another interesting growth factor release system discussed here is the HBPA membrane structure. HBPA was found to self-assemble with hyaluronic acid, a large biopolymer found in the body, into macroscopic, hierarchically-ordered membranes. Heparin was incorporated into these membranes and affected the membrane's mechanical properties and growth factor release. Human mesenchymal stem cells were also shown

  1. Intranasal epidermal growth factor treatment rescues neonatal brain injury

    PubMed Central

    Scafidi, Joseph; Hammond, Timothy R.; Scafidi, Susanna; Ritter, Jonathan; Jablonska, Beata; Roncal, Maria; Szigeti-Buck, Klara; Coman, Daniel; Huang, Yuegao; McCarter, Robert J.; Hyder, Fahmeed; Horvath, Tamas L.; Gallo, Vittorio

    2014-01-01

    There are no clinically relevant treatments available that improve function in the growing population of very preterm infants (<32 weeks gestation) with neonatal brain injury. Diffuse white matter injury (DWMI) is a common finding in these children and results in chronic neurodevelopmental impairments1,2. As shown recently, failure in oligodendrocyte progenitor cell maturation contributes to DWMI3. In a previous study, we demonstrated that epidermal growth factor receptor (EGFR) plays an important role in oligodendrocyte development4. Here, we examine whether enhanced epidermal growth factor receptor (EGFR) signaling stimulates the endogenous response of EGFR-expressing progenitor cells during a critical period after brain injury, and promotes cellular and behavioral recovery in the developing brain. Using an established model of very preterm brain injury, we demonstrate that selective overexpression of human (h)EGFR in oligodendrocyte lineage cells or the administration of intranasal heparin binding EGF immediately after injury decreases oligodendroglia death, enhances generation of new oligodendrocytes from progenitor cells (OPCs) and promotes functional recovery. Furthermore, these interventions diminish ultrastructural abnormalities and alleviate behavioral deficits on white matter-specific paradigms. Inhibition of EGFR signaling with a molecularly targeted agent used for cancer therapy demonstrates that EGFR activation is an important contributor to oligodendrocyte regeneration and functional recovery after DWMI. Thus, our study provides direct evidence that targeting EGFR in OPCs at a specific time after injury is clinically feasible and applicable for the treatment of premature children with white matter injury. PMID:24390343

  2. Cardiopulmonary Bypass Without Heparin.

    PubMed

    Rehfeldt, Kent H; Barbara, David W

    2016-03-01

    Due to familiarity, short half-life, ease of monitoring, and the availability of a reversal agent, heparin remains the anticoagulant of choice for cardiac operations requiring cardiopulmonary bypass (CPB). However, occasionally patients require CPB but should not receive heparin, most often because of acute or subacute heparin-induced thrombocytopenia (HIT). In these cases, if it is not feasible to wait for the disappearance of HIT antibodies, an alternative anticoagulant must be selected. A number of non-heparin anticoagulant options have been explored. However, current recommendations suggest the use of a direct thrombin inhibitor such as bivalirudin. This review describes the use of heparin alternatives for the conduct of CPB with a focus on the direct thrombin inhibitors. PMID:26872706

  3. Human Endothelial Cells: Use of Heparin in Cloning and Long-Term Serial Cultivation

    NASA Astrophysics Data System (ADS)

    Thornton, Susan C.; Mueller, Stephen N.; Levine, Elliot M.

    1983-11-01

    Endothelial cells from human blood vessels were cultured in vitro, with doubling times of 17 to 21 hours for 42 to 79 population doublings. Cloned human endothelial cell strains were established for the first time and had similar proliferative capacities. This vigorous cell growth was achieved by addition of heparin to culture medium containing reduced concentrations of endothelial cell growth factor. The routine cloning and long-term culture of human endothelial cells will facilitate studying the human endothelium in vitro.

  4. Structure of rat acidic fibroblast growth factor at 1.4 Å resolution

    SciTech Connect

    Kulahin, Nikolaj; Kochoyan, Arthur; Berezin, Vladimir; Bock, Elisabeth; Gajhede, Michael

    2007-02-01

    The structure of rat acidic fibroblast growth factor was determined and compared with those of human, bovine and newt origin. The rat and human structures were found to be very similar. Fibroblast growth factors (FGFs) constitute a family of 22 structurally related heparin-binding polypeptides that are involved in the regulation of cell growth, survival, differentiation and migration. Here, a 1.4 Å resolution X-ray structure of rat FGF1 is presented. Two molecules are present in the asymmetric unit of the crystal and they coordinate a total of five sulfate ions. The structures of human, bovine and newt FGF1 have been published previously. Human and rat FGF1 are found to have very similar structures.

  5. Heparin oligosaccharides: inhibitors of the biological activity of bFGF on Caco-2 cells.

    PubMed Central

    Jayson, G. C.; Gallagher, J. T.

    1997-01-01

    A number of growth factors, including members of the fibroblast growth factor (FGF) family - hepatocyte growth factor, vascular endothelial growth factor and heparin-binding epidermal growth factor - are dependent on heparan sulphate (HS) for biological activity mediated through their high-affinity signal-transducing receptors. This obligate requirement for HS prompted the search for antagonists of HS function that could be used as anti-growth factor drugs for the treatment of cancer. Basic FGF (bFGF) was the focus of this study. Caco-2, a human colon carcinoma cell line, was adapted to growth in serum-free medium so that investigation of its growth factor requirements for growth and migration could be performed in defined conditions (Jayson GC, Evans GS, Pemberton PW, Lobley RW, Allen T 1994, Cancer Res, 54, 5718-5723). This cell line multiplied and moved in a dose-dependent manner in response to bFGF. Here, we show that the mitogenic response to bFGF is dependent on the presence of heparan sulphate. A library of heparin oligosaccharides with uniform composition but variable length was generated [general formula [IdoA(2S)-GlcNS(6S)n], and oligosaccharides of defined lengths were tested for their ability to inhibit the biological activity of bFGF. While intact heparin and heparin-derived fragments of 12 monosaccharide units did not affect bFGF-induced cell division or bFGF-induced cell migration, octasaccharides and decasaccharides potently inhibited the bFGF-induced growth and migration responses. In particular, octasaccharides completely inhibited these biological activities at 10 microg ml-, a clinically achievable and tolerable concentration. This study shows that the length of an oligosaccharide determines its ability to block the biological activity of bFGF. The observation that the biological activity of cell-surface heparan sulphate can be antagonized in this way in a human carcinoma cell line suggests that oligosaccharides should be investigated further as

  6. Human recombinant interleukin-1 beta- and tumor necrosis factor alpha-mediated suppression of heparin-like compounds on cultured porcine aortic endothelial cells

    SciTech Connect

    Kobayashi, M.; Shimada, K.; Ozawa, T. )

    1990-09-01

    Cytokines are known to tip the balance of the coagulant-anticoagulant molecules on the endothelial cell surface toward intravascular coagulation. Their effects on endothelial cell surface-associated heparin-like compounds have not been examined yet. Incorporation of (35S)sulfate into heparan sulfate on cultured porcine aortic endothelial cells was suppressed by human recombinant interleukin-1 beta (rIL-1 beta) or tumor necrosis factor alpha (rTNF alpha) in a dose- and time-dependent manner with little effect on cell number, protein content, and (3H)leucine incorporation of cells. Maximal inhibition was achieved by incubation of cells with 100 ng/ml of rIL-1 beta or 5 ng/ml of rTNF alpha for 12-24 hours, resulting in a reduction of the synthesis of heparan sulfate on the cell surface by approximately 50%. The dose dependency was consistent with that seen in the stimulation of endothelial cell procoagulant activity by each cytokine. The suppression of heparan sulfate synthesis was sustained for at least 48 hours after pretreatment of cells with cytokines and was unchanged after the addition of indomethacin or polymyxin B. The rate of degradation of prelabeled 35S-heparan sulfate on the cell surface was not altered by cytokine treatments. Neither the size, the net negative charge, nor the proportion of the molecule with high affinity for antithrombin III of endothelial cell heparan sulfate was changed by cytokines. Furthermore, specific binding of 125I-labeled antithrombin III to the endothelial cell surface was reduced to 40-60% of control by cytokines. In parallel with reduction in binding, antithrombin III cofactor activity was partially diminished in cytokine-treated endothelial cells. Thus, cytokine-mediated suppression of heparin-like substance on endothelial cells appears to be another cytokine-inducible endothelial effects affecting coagulation.

  7. Growth Factor Mediated Signaling in Pancreatic Pathogenesis

    PubMed Central

    Nandy, Debashis; Mukhopadhyay, Debabrata

    2011-01-01

    Functionally, the pancreas consists of two types of tissues: exocrine and endocrine. Exocrine pancreatic disorders mainly involve acute and chronic pancreatitis. Acute pancreatitis typically is benign, while chronic pancreatitis is considered a risk factor for developing pancreatic cancer. Pancreatic carcinoma is the fourth leading cause of cancer related deaths worldwide. Most pancreatic cancers develop in the exocrine tissues. Endocrine pancreatic tumors are more uncommon, and typically are less aggressive than exocrine tumors. However, the endocrine pancreatic disorder, diabetes, is a dominant cause of morbidity and mortality. Importantly, different growth factors and their receptors play critical roles in pancreatic pathogenesis. Hence, an improved understanding of how various growth factors affect pancreatitis and pancreatic carcinoma is necessary to determine appropriate treatment. This chapter describes the role of different growth factors such as vascular endothelial growth factor (VEGF), insulin-like growth factor (IGF), platelet derived growth factor (PDGF), fibroblast growth factor (FGF), epidermal growth factor (EGF), and transforming growth factor (TGF) in various pancreatic pathophysiologies. Finally, the crosstalk between different growth factor axes and their respective signaling mechanisms, which are involved in pancreatitis and pancreatic carcinoma, are also discussed. PMID:24212642

  8. A glycosylation-deficient endothelial cell mutant with modified responses to transforming growth factor-beta and other growth inhibitory cytokines: evidence for multiple growth inhibitory signal transduction pathways.

    PubMed Central

    Fafeur, V; O'Hara, B; Böhlen, P

    1993-01-01

    An endothelial cell line (M40) resistant to growth inhibition by transforming growth factor-beta type 1 (TGF beta 1) was isolated by chemical mutagenesis and growth in the presence of TGF beta 1. Like normal endothelial cells, this mutant is characterized by high expression of type II TGF beta receptor and low expression of type I TGF beta receptor. However, the mutant cells display a type II TGF beta receptor of reduced molecular weight as a result of a general defect in N-glycosylation of proteins. The alteration does not impair TGF beta 1 binding to cell surface receptors or the ability of TGF beta 1 to induce fibronectin or plasminogen activator inhibitor-type I production. M40 cells were also resistant to growth inhibition by tumor necrosis factor alpha (TNF alpha) and interleukin-1 alpha (IL-1 alpha) but were inhibited by interferon-gamma (IFN gamma) and heparin. These results imply that TGF beta 1, TNF alpha, and IL-1 alpha act through signal transducing pathways that are separate from pathways for IFN gamma and heparin. Basic fibroblast growth factor was still mitogenic for M40, further suggesting that TGF beta 1, TNF alpha, and IL-1 alpha act by direct inhibition of cell growth rather than by interfering with growth stimulatory pathways. Images PMID:8382975

  9. Heparin-Induced Thrombocytopenia: A Comprehensive Clinical Review.

    PubMed

    Salter, Benjamin S; Weiner, Menachem M; Trinh, Muoi A; Heller, Joshua; Evans, Adam S; Adams, David H; Fischer, Gregory W

    2016-05-31

    Heparin-induced thrombocytopenia is a profoundly dangerous, potentially lethal, immunologically mediated adverse drug reaction to unfractionated heparin or, less commonly, to low-molecular weight heparin. In this comprehensive review, the authors highlight heparin-induced thrombocytopenia's risk factors, clinical presentation, pathophysiology, diagnostic principles, and treatment. The authors place special emphasis on the management of patients requiring procedures using cardiopulmonary bypass or interventions in the catheterization laboratory. Clinical vigilance of this disease process is important to ensure its recognition, diagnosis, and treatment. Misdiagnosis of the syndrome, as well as misunderstanding of the disease process, continues to contribute to its morbidity and mortality. PMID:27230048

  10. Nerve growth factor and asthma.

    PubMed

    Bonini, S; Lambiase, A; Lapucci, G; Properzi, F; Bresciani, M; Bracci Laudiero, M L; Mancini, M J; Procoli, A; Micera, A; Sacerdoti, G; Bonini, S; Levi-Schaffer, F; Rasi, G; Aloe, L

    2002-01-01

    An increasing body of evidence shows that nerve growth factor (NGF) exerts biological activity not only on the central and peripheral nervous system, but also on the immune system thereby influencing allergic diseases and asthma. (1) NGF circulating levels are increased in patients with allergic diseases and asthma, and are related to the severity of the inflammatory process and disease. In vernal keratoconjunctivitis, NGF plasma levels correlate with the number of mast cells infiltrating the conjunctiva, and NGF mRNA is increased in nasal mucosal scrapings of patients with allergic rhinitis who have high levels of NGF in serum and nasal fluids; NGF is further increased in nasal fluids after specific allergen challenge. (2) NGF is produced and released by several modulatory and effector cells of allergic inflammation and asthma, for example T-helper 2 lymphocytes, mast cells and eosinophils. (3) NGF receptors are expressed on the conjunctival epithelium of patients with allergic conjunctivitis and the number of NGF-receptor positive cells is increased in the conjunctiva of these patients. Indeed, local administration of NGF induces fibroblast activation and healing processes of human corneal ulcers, which suggests that NGF plays a role in tissue remodelling processes occurring in asthma. (4) NGF increases airway hyperreactivity to histamine in an animal model of asthma, while anti-NGF treatment reduces airway hyperreactivity induced by ovalbumin topical challenge in the sensitized mouse. PMID:12144547

  11. Circulating Fibroblast Growth Factor-2, HIV-Tat, and Vascular Endothelial Cell Growth Factor-A in HIV-Infected Children with Renal Disease Activate Rho-A and Src in Cultured Renal Endothelial Cells

    PubMed Central

    Das, Jharna R; Gutkind, J. Silvio; Ray, Patricio E

    2016-01-01

    Renal endothelial cells (REc) are the first target of HIV-1 in the kidney. The integrity of REc is maintained at least partially by heparin binding growth factors that bind to heparan sulfate proteoglycans located on their cell surface. However, previous studies showed that the accumulation of two heparin-binding growth factors, Vascular Endothelial Cell Growth Factor-A (VEGF-A) and Fibroblast Growth Factor-2 (FGF-2), in combination with the viral protein Tat, can precipitate the progression of HIV-renal diseases. Nonetheless, very little is known about how these factors affect the behavior of REc in HIV+ children. We carried out this study to determine how VEGF-A, FGF-2, and HIV-Tat, modulate the cytoskeletal structure and permeability of cultured REc, identify key signaling pathways involved in this process, and develop a functional REc assay to detect HIV+ children affected by these changes. We found that VEGF-A and FGF-2, acting in synergy with HIV-Tat and heparin, affected the cytoskeletal structure and permeability of REc through changes in Rho-A, Src, and Rac-1 activity. Furthermore, urine samples from HIV+ children with renal diseases, showed high levels of VEGF-A and FGF-2, and induced similar changes in cultured REc and podocytes. These findings suggest that FGF-2, VEGF-A, and HIV-Tat, may affect the glomerular filtration barrier in HIV+ children through the induction of synergistic changes in Rho-A and Src activity. Further studies are needed to define the clinical value of the REc assay described in this study to identify HIV+ children exposed to circulating factors that may induce glomerular injury through similar mechanisms. PMID:27097314

  12. Circulating Fibroblast Growth Factor-2, HIV-Tat, and Vascular Endothelial Cell Growth Factor-A in HIV-Infected Children with Renal Disease Activate Rho-A and Src in Cultured Renal Endothelial Cells.

    PubMed

    Das, Jharna R; Gutkind, J Silvio; Ray, Patricio E

    2016-01-01

    Renal endothelial cells (REc) are the first target of HIV-1 in the kidney. The integrity of REc is maintained at least partially by heparin binding growth factors that bind to heparan sulfate proteoglycans located on their cell surface. However, previous studies showed that the accumulation of two heparin-binding growth factors, Vascular Endothelial Cell Growth Factor-A (VEGF-A) and Fibroblast Growth Factor-2 (FGF-2), in combination with the viral protein Tat, can precipitate the progression of HIV-renal diseases. Nonetheless, very little is known about how these factors affect the behavior of REc in HIV+ children. We carried out this study to determine how VEGF-A, FGF-2, and HIV-Tat, modulate the cytoskeletal structure and permeability of cultured REc, identify key signaling pathways involved in this process, and develop a functional REc assay to detect HIV+ children affected by these changes. We found that VEGF-A and FGF-2, acting in synergy with HIV-Tat and heparin, affected the cytoskeletal structure and permeability of REc through changes in Rho-A, Src, and Rac-1 activity. Furthermore, urine samples from HIV+ children with renal diseases, showed high levels of VEGF-A and FGF-2, and induced similar changes in cultured REc and podocytes. These findings suggest that FGF-2, VEGF-A, and HIV-Tat, may affect the glomerular filtration barrier in HIV+ children through the induction of synergistic changes in Rho-A and Src activity. Further studies are needed to define the clinical value of the REc assay described in this study to identify HIV+ children exposed to circulating factors that may induce glomerular injury through similar mechanisms. PMID:27097314

  13. Improved production of recombinant fibroblast growth factor 7 (FGF7/KGF) from bacteria in high magnesium chloride.

    PubMed

    Luo, Yongde; Cho, Hyun-Hee; Jones, Richard B; Jin, Chengliu; McKeehan, Wallace L

    2004-02-01

    Because of specificity for both heparin/heparan sulfate and the receptor complex on epithelial cells relative to other fibroblast growth factor (FGF) homologues, there is considerable interest in clinical and commercial applications of FGF7 (also called keratinocyte growth factor or KGF) that require large quantities at reasonable cost. Production of recombinant FGF7 from bacteria suffers from lower yields and recovery relative to FGF1 and FGF2. Fusion of FGF7 at the N-terminus with glutathione-S-transferase (GST) followed by removal of GST by proteolysis while bound to natural ligand heparin improved the intrinsically low yields from Escherichia coli hosts to 3.2 mg per liter per OD(600), which was still only 10% of that for FGF1. Yield of the GST-FGF7 fusion product was improved to about 17 mg per liter per OD(600) in strain BL21(DE3)pLysS by inclusion of 10-100mM magnesium chloride (MgCl(2)) in the culture medium. This improved by about five times the yields of fully active 54ser-FGF7 after proteolytic excision of the GST portion from GST-FGF7 immobilized on heparin-Sepharose. This simple enhancement improves the cost-effectiveness of production of recombinant FGF7 in bacteria for clinical and commercial applications. PMID:14711521

  14. Heparin desulfation modulates VEGF release and angiogenesis in diabetic wounds.

    PubMed

    Freudenberg, Uwe; Zieris, Andrea; Chwalek, Karolina; Tsurkan, Mikhail V; Maitz, Manfred F; Atallah, Passant; Levental, Kandice R; Eming, Sabine A; Werner, Carsten

    2015-12-28

    While vascular endothelial growth factor (VEGF) has been shown to be one of the key players in wound healing by promoting angiogenesis current clinical applications of this growth factor to the wound environment are poorly controlled and not sustainable. Hydrogels made of sulfated glycosaminoglycans (GAG) allow for the sustained release of growth factors since GAGs engage in electrostatic complexation of biomolecules. In here, we explore a set of hydrogels formed of selectively desulfated heparin derivatives and star-shaped poly(ethylene glycol) with respect to VEGF binding and release and anticoagulant activity. As a proof of concept, supportive effects on migration and tube formation of human umbilical vein endothelial cells were studied in vitro and the promotion of wound healing was followed in genetically diabetic (db/db) mice. Our data demonstrate that the release of VEGF from the hydrogels is modulated in dependence on the GAG sulfation pattern. Hydrogels with low sulfate content (11% of initial heparin) were found to be superior in efficacy of VEGF administration, low anticoagulant activity and promotion of angiogenesis. PMID:26478015

  15. Intranasal epidermal growth factor treatment rescues neonatal brain injury

    NASA Astrophysics Data System (ADS)

    Scafidi, Joseph; Hammond, Timothy R.; Scafidi, Susanna; Ritter, Jonathan; Jablonska, Beata; Roncal, Maria; Szigeti-Buck, Klara; Coman, Daniel; Huang, Yuegao; McCarter, Robert J.; Hyder, Fahmeed; Horvath, Tamas L.; Gallo, Vittorio

    2014-02-01

    There are no clinically relevant treatments available that improve function in the growing population of very preterm infants (less than 32 weeks' gestation) with neonatal brain injury. Diffuse white matter injury (DWMI) is a common finding in these children and results in chronic neurodevelopmental impairments. As shown recently, failure in oligodendrocyte progenitor cell maturation contributes to DWMI. We demonstrated previously that the epidermal growth factor receptor (EGFR) has an important role in oligodendrocyte development. Here we examine whether enhanced EGFR signalling stimulates the endogenous response of EGFR-expressing progenitor cells during a critical period after brain injury, and promotes cellular and behavioural recovery in the developing brain. Using an established mouse model of very preterm brain injury, we demonstrate that selective overexpression of human EGFR in oligodendrocyte lineage cells or the administration of intranasal heparin-binding EGF immediately after injury decreases oligodendroglia death, enhances generation of new oligodendrocytes from progenitor cells and promotes functional recovery. Furthermore, these interventions diminish ultrastructural abnormalities and alleviate behavioural deficits on white-matter-specific paradigms. Inhibition of EGFR signalling with a molecularly targeted agent used for cancer therapy demonstrates that EGFR activation is an important contributor to oligodendrocyte regeneration and functional recovery after DWMI. Thus, our study provides direct evidence that targeting EGFR in oligodendrocyte progenitor cells at a specific time after injury is clinically feasible and potentially applicable to the treatment of premature children with white matter injury.

  16. Stability and biological activity evaluations of PEGylated human basic fibroblast growth factor

    PubMed Central

    Hadadian, Shahin; Shamassebi, Dariush Norouzian; Mirzahoseini, Hasan; Shokrgozar, Mohamad Ali; Bouzari, Saeid; Sepahi, Mina

    2015-01-01

    Background: Human basic fibroblast growth factor (hBFGF) is a heparin-binding growth factor and stimulates the proliferation of a wide variety of cells and tissues causing survival properties and its stability and biological activity improvements have received much attention. Materials and Methods: In the present work, hBFGF produced by engineered Escherichia coli and purified by cation exchange and heparin affinity chromatography, was PEGylated under appropriate condition employing 10 kD polyethylene glycol. The PEGylated form was separated by size exclusion chromatography. Structural, biological activity, and stability evaluations were performed using Fourier transform infrared (FITR) spectroscopy, 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyltetrazolium bromide (MTT) assay and effect denaturing agent, respectively. Results: FITR spectroscopy revealed that both PEGylated and native forms had the same structures. MTT assay showed that PEGyalated form had a 30% reduced biological activity. Fluorescence spectrophotometry indicated that the PEGylated form denatured at higher concentrations of guanidine HCl (1.2 M) compared with native, which denatured at 0.8 M guanidine HCl. Conclusions: PEGylation of hBFGF makes it more stable against denaturing agent but reduces its bioactivity up to 30%. PMID:26605215

  17. Capture of endothelial cells under flow using immobilized vascular endothelial growth factor.

    PubMed

    Smith, Randall J; Koobatian, Maxwell T; Shahini, Aref; Swartz, Daniel D; Andreadis, Stelios T

    2015-05-01

    We demonstrate the ability of immobilized vascular endothelial growth factor (VEGF) to capture endothelial cells (EC) with high specificity under fluid flow. To this end, we engineered a surface consisting of heparin bound to poly-l-lysine to permit immobilization of VEGF through the C-terminal heparin-binding domain. The immobilized growth factor retained its biological activity as shown by proliferation of EC and prolonged activation of KDR signaling. Using a microfluidic device we assessed the ability to capture EC under a range of shear stresses from low (0.5 dyne/cm(2)) to physiological (15 dyne/cm(2)). Capture was significant for all shear stresses tested. Immobilized VEGF was highly selective for EC as evidenced by significant capture of human umbilical vein and ovine pulmonary artery EC but no capture of human dermal fibroblasts, human hair follicle derived mesenchymal stem cells, or mouse fibroblasts. Further, VEGF could capture EC from mixtures with non-EC under low and high shear conditions as well as from complex fluids like whole human blood under high shear. Our findings may have far reaching implications, as they suggest that VEGF could be used to promote endothelialization of vascular grafts or neovascularization of implanted tissues by rare but continuously circulating EC. PMID:25771020

  18. Nuclear magnetic resonance characterization of the binding of peptides from HIV GP120 by heparin

    SciTech Connect

    Mahan, J.A.; Rabenstein, D.L.

    1995-12-01

    Heparin has recently been shown to inhibit the growth and replication of human immunodeficiency virus, HIV. The inhibition of HIV by heparin is believed to be partly the result of its binding to envelope glycoprotein gp120 of the virus. Amino acids 307-330 of gp120 form a heparin-binding domain having the sequence: N-N-T-R-K-S-I-R-I-Q-R-G-P-G-R-A-F-V-T-I-G-K-I-G. This paper will present results on the characterization of the interaction of heparin with synthetic peptides derived from the heparin-binding domain of gp120 of HIV using one and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Information will be presented on the amino acid residues of the peptides that are involved in the binding to heparin, the nature of the interactions between heparin and these residues, and the structure of the peptides in the peptide-heparin complexes.

  19. Autocrine growth factors and solid tumor malignancy.

    PubMed Central

    Walsh, J. H.; Karnes, W. E.; Cuttitta, F.; Walker, A.

    1991-01-01

    The ability of malignant cells to escape the constraint that normally regulate cell growth and differentiation has been a primary focus of attention for investigators of cancer cell biology. An outcome of this attention has been the discovery that the protein products of oncogenes play a role in the activation of growth signal pathways. A second outcome, possibly related to abnormal oncogene expression, has been the discovery that malignant cells frequently show an ability to regulate their own growth by the release of autocrine growth modulatory substances. Most important, the growth of certain malignant cell types has been shown to depend on autocrine growth circuits. A malignant tumor whose continued growth depends on the release of an autocrine growth factor may be vulnerable to treatment with specific receptor antagonists or immunoneutralizing antibodies designed to break the autocrine circuit. Information is rapidly emerging concerning autocrine growth factors in selected human solid tissue malignancy. Images PMID:1926844

  20. Roles for Growth Factors in Cancer Progression

    PubMed Central

    Witsch, Esther; Sela, Michael; Yarden, Yosef

    2011-01-01

    Under physiological conditions, cells receive fate-determining signals from their tissue surroundings, primarily in the form of polypeptide growth factors. Integration of these extracellular signals underlies tissue homeostasis. Although departure from homeostasis and tumor initiation are instigated by oncogenic mutations rather than by growth factors, the latter are the major regulators of all subsequent steps of tumor progression, namely clonal expansion, invasion across tissue barriers, angiogenesis, and colonization of distant niches. Here, we discuss the relevant growth factor families, their roles in tumor biology, as well as the respective downstream signaling pathways. Importantly, cancer-associated activating mutations that impinge on these pathways often relieve, in part, the reliance of tumors on growth factors. On the other hand, growth factors are frequently involved in evolvement of resistance to therapeutic regimens, which extends the roles for polypeptide factors to very late phases of tumor progression and offers opportunities for cancer therapy. PMID:20430953

  1. Growth factor involvement in tension-induced skeletal muscle growth

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.

    1993-01-01

    Long-term manned space travel will require a better understanding of skeletal muscle atrophy which results from microgravity. Astronaut strength and dexterity must be maintained for normal mission operations and for emergency situations. Although exercise in space slows the rate of muscle loss, it does not prevent it. A biochemical understanding of how gravity/tension/exercise help to maintain muscle size by altering protein synthesis and/or degradation rate should ultimately allow pharmacological intervention to prevent muscle atrophy in microgravity. The overall objective is to examine some of the basic biochemical processes involved in tension-induced muscle growth. With an experimental in vitro system, the role of exogenous and endogenous muscle growth factors in mechanically stimulated muscle growth are examined. Differentiated avian skeletal myofibers can be 'exercised' in tissue culture using a newly developed dynamic mechanical cell stimulator device which simulates different muscle activity patterns. Patterns of mechanical activity which significantly affect muscle growth and metabolic characteristics were found. Both exogenous and endogenous growth factors are essential for tension-induced muscle growth. Exogenous growth factors found in serum, such as insulin, insulin-like growth factors, and steroids, are important regulators of muscle protein turnover rates and mechanically-induced muscle growth. Endogenous growth factors are synthesized and released into the culture medium when muscle cells are mechanically stimulated. At least one family of mechanically induced endogenous factors, the prostaglandins, help to regulate the rates of protein turnover in muscle cells. Endogenously synthesized IGF-1 is another. The interaction of muscle mechanical activity and these growth factors in the regulation of muscle protein turnover rates with our in vitro model system is studied.

  2. The effect of Heparin-VEGF multilayer on the biocompatibility of decellularized aortic valve with platelet and endothelial progenitor cells.

    PubMed

    Ye, Xiaofeng; Wang, Haozhe; Zhou, Jingxin; Li, Haiqing; Liu, Jun; Wang, Zhe; Chen, Anqing; Zhao, Qiang

    2013-01-01

    The application of polyelectrolyte multilayer films is a new, versatile approach to surface modification of decellularized tissue, which has the potential to greatly enhance the functionality of engineered tissue constructs derived from decellularized organs. In the present study, we test the hypothesis that Heparin- vascular endothelial growth factor (VEGF) multilayer film can not only act as an antithrombotic coating reagent, but also induce proliferation of endothelial progenitor cells (EPCs) on the decellularized aortic heart valve. SEM demonstrated the adhesion and geometric deformation of platelets. The quantitative assay of platelet activation was determined by measuring the production of soluble P-selectin. Binding and subsequent release of heparin and VEGF from valve leaflets were assessed qualitatively by laser confocal scanning microscopy and quantitatively by ELISA methods. Human blood derived EPCs were cultured and the adhesion and growth of EPCs on the surface modified valvular scaffolds were assessed. The results showed that Heparin-VEGF multilayer film improved decellularized valve haemocompatibility with respect to a substantial reduction of platelet adhesion. Release of VEGF from the decellularized heart valve leaflets at physiological conditions was sustained over 5 days. In vitro biological tests demonstrated that EPCs achieved better adhesion, proliferation and migration on the coatings with Heparin-VEGF multilayer film. Combined, these results indicate that Heparin-VEGF multilayer film could be used to cover the decellularized porcine aortic valve to decrease platelet adhesion while exhibiting excellent EPCs biocompatibility. PMID:23359625

  3. Growth factors from genes to clinical application

    SciTech Connect

    Sara, V.R. ); Hall, K.; Low, H. )

    1990-01-01

    The last decade has witnessed an explosion in the identification of growth factors and their receptors. This has been greatly facilitated by recombinant DNA technology, which has provided the tools not only to identify these proteins at the gene level but also to produce recombinant proteins for evaluating their biological activities. With the help of such techniques, we are moving toward an understanding of the biosynthesis of growth factors and their receptors, structure-function relationships, as well as mechanisms for intracellular signal transmission. The possibility of modifying these factors has opened new fields of clinical application. In this paper, four major areas of growth factor research are presented: the characterization of growth factor genes and their protein products, growth factor receptors and signal transduction by the receptors to mediate biological action, the biological actions of the various growth factors, and the role of growth factors in health and disease and their possible clinical application. Some of the topics covered include: structure of the IGFs and their variants; isoforms of PDGF receptor types; tyrosine kinase activation; structure of G-proteins in biological membranes; possible therapeutic application of NGF in the treatment of Parkinson's and Alzheimer's diseases; PDGF's possible role in the development of several fibroproliferative diseases and its therapeutic application in wound healing; and the possible use of angiogenic inhibitors in tumor treatment.

  4. Growth factors for the treatment of ischemic brain injury (growth factor treatment).

    PubMed

    Larpthaveesarp, Amara; Ferriero, Donna M; Gonzalez, Fernando F

    2015-01-01

    In recent years, growth factor therapy has emerged as a potential treatment for ischemic brain injury. The efficacy of therapies that either directly introduce or stimulate local production of growth factors and their receptors in damaged brain tissue has been tested in a multitude of models for different Central Nervous System (CNS) diseases. These growth factors include erythropoietin (EPO), vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor (BDNF), and insulin-like growth factor (IGF-1), among others. Despite the promise shown in animal models, the particular growth factors that should be used to maximize both brain protection and repair, and the therapeutic critical period, are not well defined. We will review current pre-clinical and clinical evidence for growth factor therapies in treating different causes of brain injury, as well as issues to be addressed prior to application in humans. PMID:25942688

  5. Growth factor involvement in tension-induced skeletal muscle growth

    NASA Technical Reports Server (NTRS)

    Vandenburgh, H. H.

    1987-01-01

    Muscle tissue culture techniques were developed to grow skeletal myofibers which differentiate into more adult-like myofibers. Mechanical simulation studies of these muscle cells in a newly developed mechanical cell simulator can now be performed to study growth processes in skeletal muscle. Conditions in the mechanical cell simulator were defined where mechanical activity can either prevent muscle wasting or stimulate muscle growth. The role of endogenous and exogenous growth factors in tension-induced muscle growth is being investigated under the defined conditions of tissue culture.

  6. Environmental factors influencing growth and pubertal development.

    PubMed Central

    Delemarre-van de Waal, H A

    1993-01-01

    Postnatal growth is based on hereditary signals and environmental factors in a complex regulatory network. Each factor must be in an optimal state for normal growth of the child. Fetal conditions may also have consequences on postnatal height. Intrauterine growth retardation can be recovered postnatally, although postnatal growth remains depressed in about one-third of cases. After birth, the environment may exert either a positive or negative effect on growth. In underdeveloped countries, malnutrition plays a major role in inhibiting the growth process. Children from families of higher socioeconomic classes are taller than their coevals in the lower socioeconomic groups. Urbanization also has a positive effect on growth. Better child care is supported by sufficient food supply, appropriate health and sanitation services, and a higher level of education. Over the last century, these factors have induced a taller stature and a more rapid maturity in Europe, North America, and Australia; a phenomenon which has been referred to as "the secular trend" in growth. Recently, a secular trend has also been reported in some developing countries. Although urbanization in general appears to be associated with better conditions of living, this is not the case in the slums of South America or in Africa where rural children are better off than children living in the poor cities. This paper describes in more detail the different hereditary and environmental factors that act during the fetal period and postnatally, and which play a role in human growth and pubertal development. PMID:8243404

  7. Vascular growth factors in neuropsychiatry

    PubMed Central

    Newton, Samuel S.; Fournier, Neil M.; Duman, Ronald S.

    2014-01-01

    Recent advances in understanding the cellular and molecular basis of psychiatric illnesses have shed light on the important role played by trophic factors in modulating functional parameters associated with disease causality and drug action. Disease mechanisms are now thought to involve multiple cell types, including neurons and endothelial cells. These functionally distinct but interactively coupled cell types engage in cellular cross talk via shared and common signaling molecules. Dysregulation in their cellular signaling pathways influences brain function and alters behavioral performance. Multifunctional trophic factors such as VEGF and EPO that possess both neurotrophic and angiogenic actions are of particular interest due to their ability to rescue structural and plasticity deficits in neurons and vasculature. Obtaining insight into the behavioral, cellular and molecular actions of multi-functional trophic factors has the potential to open new and transformative therapeutic approaches. PMID:23475069

  8. [Interaction of heparin with amino group-containing materials].

    PubMed

    Nemets, E A; Kasatov, D A; Sevast'ianov, V I

    2001-01-01

    The influence of the glass surface immobilized aminogroups nature and the experiments conditions on the interactions between heparin and aminogroups containing surface was studied using total internal reflections fluorescence. It was shown, that the nature of the terminating aminogroup, but not its mobility or the amount of the aminogroups in the main chain, is the major factor influencing the heparin adsorbtion from individual solution. Both the nature of terminating aminogroup and its mobility determine heparin adsorption on the aminogroups containing surfaces from the blood plasma proteins containing solution. Heparin irreversibly adsorbed from individual solution is not replaced by blood plasma proteins. The tertiary aminogroups containing surface adsorbs maximal quantity of the heparin. PMID:11766264

  9. Heparin-induced thrombocytopenia: pathophysiology and new treatment options.

    PubMed

    Harenberg, J; Jörg, I; Fenyvesi, T

    2002-01-01

    Heparin induced thrombocytopenia (HIT) is a severe complication of heparin therapy. It is generally accompanied by a paradoxical decrease in platelets leading to activation of platelets and of the coagulation system. HIT type I is a mild, transient, non-immune disorder. HIT type II is an immune-mediated reaction towards neo-antigen on PF4, which is platelet factor 4 (PF4) that is exposed upon binding to heparins. A low sulfated octasaccharide is required for binding to PF4. The generated immunoglobulines bridge platelets by binding to the FcgRIIa-receptor. In patients with HIT type II heparin/LMW-heparin has to be discontinued immediately upon clinical suspicion. Diagnosis can be confirmed by laboratory tests. As patients are at high risk for or because they have developed thromboembolism, anticoagulation is mandatory, despite thrombocytopenia. Treatment options are danaparoid, r-hirudin, bivalirudin, argatroban, dextransulfate, and dermatansulfate. In future, fondaparinux and ximelagatran may be considered for treatment. PMID:13679659

  10. Intraoperative management of patients with heparin-induced thrombocytopenia.

    PubMed

    Kappa, J R; Fisher, C A; Todd, B; Stenach, N; Bell, P; Campbell, F; Ellison, N; Addonizio, V P

    1990-05-01

    For 11 patients with confirmed heparin-induced thrombocytopenia, we used reversible platelet inhibition with iloprost, a stable prostacyclin analogue, to permit safe heparin administration for cardiac (n = 9) or vascular (n = 2) operations. In vitro, iloprost (0.01 mumol/L) prevented both heparin-induced platelet aggregation and 14C-serotonin release in all patients. Therefore, intraoperatively, a continuous infusion of iloprost was started before administration of heparin and was continued until 15 minutes after administration of protamine. For cardiac patients, after heparin administration, the whole blood platelet count did not change (171,000 +/- 29,000/microL versus 174,000 +/- 29,000/microL, mean +/- standard error of the mean); no spontaneous platelet aggregation was observed, and plasma levels of the alpha-granule constituents platelet factor 4 and beta-thromboglobulin increased from 38 +/- 14 and 140 +/- 18 ng/mL to 591 +/- 135 and 235 +/- 48 ng/mL, respectively. Fibrinopeptide A levels actually decreased from 287 +/- 150 to 27 +/- 6 ng/mL. Furthermore, adenosine diphosphate-induced platelet activation was preserved, postoperative bleeding times were unchanged, and no heparin-related deaths occurred. Similar results were obtained in both vascular patients. We conclude that temporary platelet inhibition with iloprost now permits safe heparin administration in all patients with heparin-induced thrombocytopenia who require a cardiac or vascular operation. PMID:1692679

  11. Autocrine ligands of the epithelial growth factor receptor mediate inflammatory responses to diesel exhaust particles

    PubMed Central

    2014-01-01

    Background Diesel exhaust is associated with cardiovascular and respiratory mortality and morbidity. Acute exposure leads to increased IL-8 expression and airway neutrophilia, however the mechanism of this response is unknown. Objectives: As cigarette smoke-induced IL-8 expression by epithelial cells involves transactivation of the epidermal growth factor receptor (EGFR), we studied the effects of diesel exhaust particles (DEP) on IL-8 release and the role of the EGFR. Methods Primary bronchial epithelial cells (PBEC) were exposed to DEPs or carbon black. IL-8 and EGFR ligand expression (transforming growth factor alpha (TGFα), heparin-binding EGF-like growth factor, and amphiregulin (AR)) were assessed by quantitative RT-PCR and ELISA. Results DEP, but not carbon black, caused a dose-dependent increase in mitogen-activated protein kinase (MAPK) activation and IL-8 expression, however above 50 μg/ml there was an increase in cytotoxicity. At 50 μg/ml, DEPs stimulated transcription and release of IL-8 and EGFR ligands. IL-8 release was blocked by EGFR neutralizing antibodies, an EGFR-selective tyrosine kinase inhibitor and by the metalloprotease inhibitor, GM6001, which blocks EGFR ligand shedding. Neutralizing antibodies to AR, TGFα and heparin-binding (HB)-EGF reduced DEP-induced IL-8 by >50%. Conclusion Expression of IL-8 in response to DEPs is dependent on EGFR activation and that autocrine production of EGFR ligands makes a substantial contribution to this response. Capsule Summary: This study identifies a mechanism whereby diesel particles stimulates IL-8 release from bronchial epithelial cells. This mechanism may help to explain the recruitment of neutrophils into the airways of people exposed to particulate air pollution. PMID:24555532

  12. New Clue Found to Growth Factor Action.

    ERIC Educational Resources Information Center

    Hoffman, Michelle

    1991-01-01

    Discussed is the discovery which may help to explain epidermal growth factor effects on the cell skeleton. The role of a protein called profilin in the regulation of the microfilament system is described. (CW)

  13. Expression of growth factors in Dictyostelium discoideum.

    PubMed

    Asgari, S; Arun, S; Slade, M B; Marshall, J; Williams, K L; Wheldrake, J F

    2001-07-01

    Growth factors and their binding proteins are important proteins regulating mammalian cell proliferation and differentiation so there is considerable interest in producing them as recombinant proteins, especially in hosts that do not already produce a complex mixture of growth factors. Many growth factors require post-translational modifications making them unsuitable for production in Escherichia coli or other prokaryotes. Since several expression vector systems have been recently developed for foreign protein production in the cellular slime mould, Dictyostelium discoideum, we attempted to use two of these systems to express human insulin-like growth factor binding protein 6 (hIGFBP6) and bovine beta-cellulin (bBTC) as secreted proteins. Although both proteins were successfully produced in stably transformed amoebae, no secretion was detected in spite of several attempts to facilitate this occurring. PMID:11361083

  14. [T-LYMPHOCYTES AND TISSUE GROWTH FACTORS].

    PubMed

    Tishevskaya, N V; Gevorkyan, N M; Kozlova, N I

    2015-08-01

    Lympnoici regulation, in aciaition to ensuring tne protection of tne antigen, is aimecl at maintaining a qualitative, quantitative, structural and functional integrity of the body. T-lymphocytes and growth factors are involved in cell proliferation, differentiation, and tissue and organ regeneration. Lymphocyte's, sensitivity to homeostasis changes and their morphogenetic function are connected with a large number of receptors to bioactive substances and with their ability to syn- thesize and secrete hormones and tissue growth factors. At the same time tissue growth factors are involved in the development of thymocytes, in the differentiation of T helper and cytotoxic lymphocytes. Growth factors modulate the functions of Thl, Th2, Treg, Thl7, Th9. The important aspects of the interaction of T cells and EGF, TGF-P, FGF, VEGF, PlGF, HGF/SF in normal and pathological conditions are shown in this review. PMID:26591583

  15. Intracellular protein delivery activity of peptides derived from insulin-like growth factor binding proteins 3 and 5

    SciTech Connect

    Goda, Natsuko; Tenno, Takeshi; Inomata, Kosuke; Shirakawa, Masahiro; Tanaka, Toshiki; Hiroaki, Hidekazu

    2008-08-01

    Insulin-like growth factor binding proteins (IGFBPs) have various IGF-independent cellular activities, including receptor-independent cellular uptake followed by transcriptional regulation, although mechanisms of cellular entry remain unclear. Herein, we focused on their receptor-independent cellular entry mechanism in terms of protein transduction domain (PTD) activity, which is an emerging technique useful for clinical applications. The peptides of 18 amino acid residues derived from IGFBP-3 and IGFBP-5, which involve heparin-binding regions, mediated cellular delivery of an exogenous protein into NIH3T3 and HeLa cells. Relative protein delivery activities of IGFBP-3/5-derived peptides were approximately 20-150% compared to that of the HIV-Tat peptide, a potent PTD. Heparin inhibited the uptake of the fusion proteins with IGFBP-3 and IGFBP-5, indicating that the delivery pathway is heparin-dependent endocytosis, similar to that of HIV-Tat. The delivery of GST fused to HIV-Tat was competed by either IGFBP-3 or IGFBP-5-derived synthetic peptides. Therefore, the entry pathways of the three PTDs are shared. Our data has shown a new approach for designing protein delivery systems using IGFBP-3/5 derived peptides based on the molecular mechanisms of IGF-independent activities of IGFBPs.

  16. Synthesis and detection of N-sulfonated oversulfated chondroitin sulfate in marketplace heparin.

    PubMed

    Mans, Daniel J; Ye, Hongping; Dunn, Jamie D; Kolinski, Richard E; Long, Dianna S; Phatak, Nisarga L; Ghasriani, Houman; Buhse, Lucinda F; Kauffman, John F; Keire, David A

    2015-12-01

    N-sulfonated oversulfated chondroitin sulfate (NS-OSCS), recently reported as a potential threat to the heparin supply, was prepared along with its intermediate derivatives. All compounds were spiked into marketplace heparin and subjected to United States Pharmacopeia (USP) identification assays for heparin (proton nuclear magnetic resonance [(1)H NMR], chromatographic identity, % galactosamine [%GalN], anti-factor IIa potency, and anti-factor Xa/IIa ratio). The U.S. Food and Drug Administration (FDA) strong-anionic exchange high-performance liquid chromatography (SAX-HPLC) method resolved NS-OSCS from heparin and OSCS and had a limit of detection of 0.26% (w/w) NS-OSCS. The %GalN test was sensitive to the presence of NS-OSCS in heparin. Therefore, current USP heparin monograph tests (i.e., SAX-HPLC and %GalN) detect the presence of NS-OSCS in heparin. PMID:26278168

  17. Fibrin Encapsulation and Vascular Endothelial Growth Factor Delivery Promotes Ovarian Graft Survival in Mice

    PubMed Central

    Shikanov, Ariella; Zhang, Zheng; Xu, Min; Smith, Rachel M.; Rajan, Aniruddha; Woodruff, Teresa K.

    2011-01-01

    Ovarian cryopreservation before chemotherapy and autotransplantation post-treatment can restore fertility to women with premature ovarian failure. Although the majority of primordial follicles survive the cryopreservation cycle, the follicular pool is reduced after transplantation due to ischemic death. Therefore, we engineered a biomaterial-based system to promote angiogenesis in a mouse model of ovarian transplantation. To mimic the clinical situation of sterility, a bilateral ovariectomy was performed 2 weeks before transplantation, during which time serum levels of follicular stimulating hormone rose to menopausal levels. Before transplantation, vitrified/thawed ovarian tissue from 12-day-old C57Bl/6J pups was encapsulated in fibrin modified with heparin-binding peptide (HBP), heparin, and loaded with 0.5 μg vascular endothelial growth factor (VEGF). The group transplanted with fibrin-HBP-VEGF had twice as many surviving primordial follicles and an increased number of blood vessels relative to the no biomaterial control. Transplanted tissue was viable and supported natural conception that led to live and healthy offspring. The timeline of live births with VEGF delivery suggested that primary follicles survived transplantation, and provided the gametes for the first litter. Thus, VEGF delivery from fibrin supported integration of the transplant with the host, promoted angiogenesis, and enhanced engraftment and function of the tissue. PMID:21740332

  18. Predictive factors for intrauterine growth restriction

    PubMed Central

    Albu, AR; Anca, AF; Horhoianu, VV; Horhoianu, IA

    2014-01-01

    Abstract Reduced fetal growth is seen in about 10% of the pregnancies but only a minority has a pathological background and is known as intrauterine growth restriction or fetal growth restriction (IUGR / FGR). Increased fetal and neonatal mortality and morbidity as well as adult pathologic conditions are often associated to IUGR. Risk factors for IUGR are easy to assess but have poor predictive value. For the diagnostic purpose, biochemical serum markers, ultrasound and Doppler study of uterine and spiral arteries, placental volume and vascularization, first trimester growth pattern are object of assessment today. Modern evaluations propose combined algorithms using these strategies, all with the goal of a better prediction of risk pregnancies. Abbreviations: SGA = small for gestational age; IUGR = intrauterine growth restriction; FGR = fetal growth restriction; IUFD = intrauterine fetal demise; HIV = human immunodeficiency virus; PAPP-A = pregnancy associated plasmatic protein A; β-hCG = beta human chorionic gonadotropin; MoM = multiple of median; ADAM-12 = A-disintegrin and metalloprotease 12; PP-13 = placental protein 13; VEGF = vascular endothelial growth factor; PlGF = placental growth factor; sFlt-1 = soluble fms-like tyrosine kinase-1; UAD = uterine arteries Doppler ultrasound; RI = resistence index; PI = pulsatility index; VOCAL = Virtual Organ Computer–Aided Analysis software; VI = vascularization index; FI = flow index; VFI = vascularization flow index; PQ = placental quotient PMID:25408721

  19. Organic growth factor requirements of some yeasts.

    PubMed

    Madan, M; Gulati, N

    1980-01-01

    Some sporogenous yeasts (Brettanomyces bruxellensis, Debaryomyces hansenii, Hansenula ciferrii, Hansenula polymorpha, Pichia polymorpha, Saccharomycopsis guttulata, and Saccharomyces chevalieri), isolated from various fruits have been examined for their organic growth factor requisites. H. ciferrii was completely deficient in thiamine, biotin, inositol, riboflavin, niacin, and partially deficient in pantothenic acid. It required an external supply of 0.1-1.0 ppm thiamine, 0.01-0.1 ppm biotin, 10.0 ppm inositol, 0.10 ppm niacin and riboflavin for its optimum growth. H. polymorpha showed partial deficiency only in xanthine. P. polymorpha gave indications of partial deficiencies in thiamine and biotin. S. guttulata was completely deficient in biotin, and partially deficient in adenine sulphate. It required 0.01 ppm biotin for optimum growth. S chevalieri was completely deficient in pyridoxine and partially deficient in thiamine. It required 0.1 ppm pyridoxine for maximum growth. D. hansenii and B bruxellensis were auxoautotrophic for the various growth factors studied. PMID:7242379

  20. Interaction of the 268-282 region of glycoprotein Ibalpha with the heparin-binding site of thrombin inhibits the enzyme activation of factor VIII.

    PubMed Central

    De Cristofaro, R; De Filippis, V

    2003-01-01

    Activation of factor VIII (FVIII) by thrombin plays a fundamental role in the amplification of the coagulation cascade and takes place through specific proteolytic cleavages at Arg(372), Arg(740) and Arg(1689). Full FVIII activation requires cleavage at Arg(372), a process involving the alpha-thrombin exosite-II; referred to as heparin-binding site (HBS). The present study was aimed at investigating the effect of glycoprotein Ibalpha (GpIbalpha; 1-282 fragment) binding to thrombin HBS on FVIII activation. Similar experiments were also performed using a synthetic peptide modelled on the 268-282 sequence of GpIbalpha, and sulphated successfully at all tyrosine residues present along its sequence, at positions 276, 278 and 279. Both GpIbalpha 1-282 and the sulphated GpIb 268-282 peptides induced a progressive decrease (up to 70%) in activated FVIII generation, assessed by coagulation and FXa-generation assays. Furthermore, SDS/PAGE and Western-blot experiments showed that the specific appearance of the 44 kDa A2 domain on cleavage of the FVIII Arg(372)-Ser(373) peptide bond was delayed significantly in the presence of either GpIbalpha 1-282 or GpIb 268-282 peptide. Moreover, the effect of the latter on thrombin-mediated hydrolysis of a peptide having the sequence 341-376 of FVIII was investigated using reverse-phase HPLC. The k (cat)/ K (m) values of the FVIII 341-376 peptide hydrolysis by thrombin decreased linearly as a function of the GpIbalpha 268-282 peptide concentration, according to a competitive inhibition effect. Taken together, these experiments suggest that the sulphated 268-282 region of GpIbalpha binds to thrombin HBS, and is responsible for the inhibition of the Arg(372)-Ser(373) bond cleavage and activation of FVIII. PMID:12689334

  1. Multifunctional silk-heparin biomaterials for vascular tissue engineering applications

    PubMed Central

    Seib, F. Philipp; Herklotz, Manuela; Burke, Kelly A.; Maitz, Manfred F.; Werner, Carsten; Kaplan, David L.

    2013-01-01

    Over the past 30 years, silk has been proposed for numerous biomedical applications that go beyond its traditional use as a suture material. Silk sutures are well tolerated in humans, but the use of silk for vascular engineering applications still requires extensive biocompatibility testing. Some studies have indicated a need to modify silk to yield a hemocompatible surface. This study examined the potential of low molecular weight heparin as a material for refining silk properties by acting as a carrier for vascular endothelial growth factor (VEGF) and improving silk hemocompatibility. Heparinized silk showed a controlled VEGF release over 6 days; the released VEGF was bioactive and supported the growth of human endothelial cells. Silk samples were then assessed using a humanized hemocompatibility system that employs whole blood and endothelial cells. The overall thrombogenic response for silk was very low and similar to the clinical reference material polytetrafluoroethylene. Despite an initial inflammatory response to silk, apparent as complement and leukocyte activation, the endothelium was maintained in a resting, anticoagulant state. The low thrombogenic response and the ability to control VEGF release support the further development of silk for vascular applications. PMID:24099708

  2. Placenta Growth Factor in Diabetic Wound Healing

    PubMed Central

    Cianfarani, Francesca; Zambruno, Giovanna; Brogelli, Laura; Sera, Francesco; Lacal, Pedro Miguel; Pesce, Maurizio; Capogrossi, Maurizio C.; Failla, Cristina Maria; Napolitano, Monica; Odorisio, Teresa

    2006-01-01

    Reduced microcirculation and diminished expression of growth factors contribute to wound healing impairment in diabetes. Placenta growth factor (PlGF), an angiogenic mediator promoting pathophysiological neovascularization, is expressed during cutaneous wound healing and improves wound closure by enhancing angiogenesis. By using streptozotocin-induced diabetic mice, we here demonstrate that PlGF induction is strongly reduced in diabetic wounds. Diabetic transgenic mice overexpressing PlGF in the skin displayed accelerated wound closure compared with diabetic wild-type littermates. Moreover, diabetic wound treatment with an adenovirus vector expressing the human PlGF gene (AdCMV.PlGF) significantly accelerated the healing process compared with wounds treated with a control vector. The analysis of treated wounds showed that PlGF gene transfer improved granulation tissue formation, maturation, and vascularization, as well as monocytes/macrophages local recruitment. Platelet-derived growth factor, fibroblast growth factor-2, and vascular endothelial growth factor mRNA levels were increased in AdCMV.PlGF-treated wounds, possibly enhancing PlGF-mediated effects. Finally, PlGF treatment stimulated cultured dermal fibroblast migration, pointing to a direct role of PlGF in accelerating granulation tissue maturation. In conclusion, our data indicate that reduced PlGF expression contributes to impaired wound healing in diabetes and that PlGF gene transfer to diabetic wounds exerts therapeutic activity by promoting different aspects of the repair process. PMID:17003476

  3. Monitoring Low Molecular Weight Heparins at Therapeutic Levels: Dose-Responses of, and Correlations and Differences between aPTT, Anti-Factor Xa and Thrombin Generation Assays

    PubMed Central

    Thomas, Owain; Lybeck, Emanuel; Strandberg, Karin; Tynngård, Nahreen; Schött, Ulf

    2015-01-01

    Background Low molecular weight heparins (LMWH’s) are used to prevent and treat thrombosis. Tests for monitoring LMWH’s include anti-factor Xa (anti-FXa), activated partial thromboplastin time (aPTT) and thrombin generation. Anti-FXa is the current gold standard despite LMWH’s varying affinities for FXa and thrombin. Aim To examine the effects of two different LMWH’s on the results of 4 different aPTT-tests, anti-FXa activity and thrombin generation and to assess the tests’ concordance. Method Enoxaparin and tinzaparin were added ex-vivo in concentrations of 0.0, 0.5, 1.0 and 1.5 anti-FXa international units (IU)/mL, to blood from 10 volunteers. aPTT was measured using two whole blood methods (Free oscillation rheometry (FOR) and Hemochron Jr (HCJ)) and an optical plasma method using two different reagents (ActinFSL and PTT-Automat). Anti-FXa activity was quantified using a chromogenic assay. Thrombin generation (Endogenous Thrombin Potential, ETP) was measured on a Ceveron Alpha instrument using the TGA RB and more tissue-factor rich TGA RC reagents. Results Methods’ mean aPTT at 1.0 IU/mL LMWH varied between 54s (SD 11) and 69s (SD 14) for enoxaparin and between 101s (SD 21) and 140s (SD 28) for tinzaparin. ActinFSL gave significantly shorter aPTT results. aPTT and anti-FXa generally correlated well. ETP as measured with the TGA RC reagent but not the TGA RB reagent showed an inverse exponential relationship to the concentration of LMWH. The HCJ-aPTT results had the weakest correlation to anti-FXa and thrombin generation (Rs0.62–0.87), whereas the other aPTT methods had similar correlation coefficients (Rs0.80–0.92). Conclusions aPTT displays a linear dose-respone to LMWH. There is variation between aPTT assays. Tinzaparin increases aPTT and decreases thrombin generation more than enoxaparin at any given level of anti-FXa activity, casting doubt on anti-FXa’s present gold standard status. Thrombin generation with tissue factor-rich activator is

  4. Heparin: Past, Present, and Future.

    PubMed

    Oduah, Eziafa I; Linhardt, Robert J; Sharfstein, Susan T

    2016-01-01

    Heparin, the most widely used anticoagulant drug in the world today, remains an animal-derived product with the attendant risks of adulteration and contamination. A contamination crisis in 2007-2008 increased the impetus to provide non-animal-derived sources of heparin, produced under cGMP conditions. In addition, recent studies suggest that heparin may have significant antineoplastic activity, separate and distinct from its anticoagulant activity, while other studies indicate a role for heparin in treating inflammation, infertility, and infectious disease. A variety of strategies have been proposed to produce a bioengineered heparin. In this review, we discuss several of these strategies including microbial production, mammalian cell production, and chemoenzymatic modification. We also propose strategies for creating "designer" heparins and heparan-sulfates with various biochemical and physiological properties. PMID:27384570

  5. Epidermal growth factor receptor-dependent stimulation of amphiregulin expression in androgen-stimulated human prostate cancer cells.

    PubMed Central

    Sehgal, I; Bailey, J; Hitzemann, K; Pittelkow, M R; Maihle, N J

    1994-01-01

    Amphiregulin is a heparin-binding epidermal growth factor (EGF)-related peptide that binds to the EGF receptor (EGF-R) with high affinity. In this study, we report a role for amphiregulin in androgen-stimulated regulation of prostate cancer cell growth. Androgen is known to enhance EGF-R expression in the androgen-sensitive LNCaP human prostate carcinoma cell line, and it has been suggested that androgenic stimuli may regulate proliferation, in part, through autocrine mechanisms involving the EGF-R. In this study, we demonstrate that LNCaP cells express amphiregulin mRNA and peptide and that this expression is elevated by androgenic stimulation. We also show that ligand-dependent EGF-R stimulation induces amphiregulin expression and that androgenic effects on amphiregulin synthesis are mediated through this EGF-R pathway. Parallel studies using the estrogen-responsive breast carcinoma cell line, MCF-7, suggest that regulation of amphiregulin by estrogen may also be mediated via an EGF-R pathway. In addition, heparin treatment of LNCaP cells inhibits androgen-stimulated cell growth further suggesting that amphiregulin can mediate androgen-stimulated LNCaP proliferation. Together, these results implicate an androgen-regulated autocrine loop composed of amphiregulin and its receptor in prostate cancer cell growth and suggest that the mechanism of steroid hormone regulation of amphiregulin synthesis may occur through androgen upregulation of the EGF-R and subsequent receptor-dependent pathways. Images PMID:8049525

  6. Heparin-Based Coacervate of FGF2 Improves Dermal Regeneration by Asserting a Synergistic Role with Cell Proliferation and Endogenous Facilitated VEGF for Cutaneous Wound Healing.

    PubMed

    Wu, Jiang; Ye, Jingjing; Zhu, Jingjing; Xiao, Zecong; He, Chaochao; Shi, Hongxue; Wang, Yadong; Lin, Cai; Zhang, Hongyu; Zhao, Yingzheng; Fu, Xiaobing; Chen, Hong; Li, Xiaokun; Li, Lin; Zheng, Jie; Xiao, Jian

    2016-06-13

    Effective wound healing requires complicated, coordinated interactions and responses at protein, cellular, and tissue levels involving growth factor expression, cell proliferation, wound closure, granulation tissue formation, and vascularization. In this study, we develop a heparin-based coacervate consisting of poly(ethylene argininylaspartate digylceride) (PEAD) as a storage matrix, heparin as a bridge, and fibroblast growth factor-2 (FGF2) as a cargo (namely heparin-FGF2@PEAD) for wound healing. First, in vitro characterization demonstrates the loading efficiency and control release of FGF2 from the heparin-FGF2@PEAD coacervate. The following in vivo studies examine the wound healing efficiency of the heparin-FGF2@PEAD coacervate upon delivering FGF2 to full-thickness excisional skin wounds in vivo, in comparison with the other three control groups with saline, heparin@PEAD as vehicle, and free FGF2. Collective in vivo data show that controlled release of FGF2 to the wounds by the coacervate significantly accelerates the wound healing by promoting cell proliferation, stimulating the secretion of vascular endothelial growth factor (VEGF) for re-epithelization, collagen deposition, and granulation tissue formation, and enhancing the expression of platelet endothelial cell adhesion molecule (CD31) and alpha-smooth muscle actin (α-SMA) for blood vessel maturation. In parallel, no obvious wound healing effect is found for the control, vehicle, and free FGF2 groups, indicating the important role of the coavervate in the wound healing process. This work designs a suitable delivery system that can protect and release FGF2 in a sustained and controlled manner, which provides a promising therapeutic potential for topical treatment of wounds. PMID:27196997

  7. Heparin-Binding Motifs and Biofilm Formation by Candida albicans

    PubMed Central

    Green, Julianne V.; Orsborn, Kris I.; Zhang, Minlu; Tan, Queenie K. G.; Greis, Kenneth D.; Porollo, Alexey; Andes, David R.; Long Lu, Jason; Hostetter, Margaret K.

    2013-01-01

    Candida albicans is a leading pathogen in infections of central venous catheters, which are frequently infused with heparin. Binding of C. albicans to medically relevant concentrations of soluble and plate-bound heparin was demonstrable by confocal microscopy and enzyme-linked immunosorbent assay (ELISA). A sequence-based search identified 34 C. albicans surface proteins containing ≥1 match to linear heparin-binding motifs. The virulence factor Int1 contained the most putative heparin-binding motifs (n = 5); peptides encompassing 2 of 5 motifs bound to heparin-Sepharose. Alanine substitution of lysine residues K805/K806 in 804QKKHQIHK811 (motif 1 of Int1) markedly attenuated biofilm formation in central venous catheters in rats, whereas alanine substitution of K1595/R1596 in 1593FKKRFFKL1600 (motif 4 of Int1) did not impair biofilm formation. Affinity-purified immunoglobulin G (IgG) recognizing motif 1 abolished biofilm formation in central venous catheters; preimmune IgG had no effect. After heparin treatment of C. albicans, soluble peptides from multiple C. albicans surface proteins were detected, such as Eno1, Pgk1, Tdh3, and Ssa1/2 but not Int1, suggesting that heparin changes candidal surface structures and may modify some antigens critical for immune recognition. These studies define a new mechanism of biofilm formation for C. albicans and a novel strategy for inhibiting catheter-associated biofilms. PMID:23904295

  8. Post Treatment With an FGF Chimeric Growth Factor Enhances Epithelial Cell Proliferation to Improve Recovery From Radiation-Induced Intestinal Damage

    SciTech Connect

    Nakayama, Fumiaki; Hagiwara, Akiko; Umeda, Sachiko; Asada, Masahiro; Goto, Megumi; Oki, Junko; Suzuki, Masashi; Imamura, Toru; Akashi, Makoto

    2010-11-01

    Purpose: A fibroblast growth factor (FGF) 1-FGF2 chimera (FGFC) was created previously and showed greater structural stability than FGF1. This chimera was capable of stimulating epithelial cell proliferation much more strongly than FGF1 or FGF2 even without heparin. Therefore FGFC was expected to have greater biologic activity in vivo. This study evaluated and compared the protective activity of FGFC and FGF1 against radiation-induced intestinal injuries. Methods and Materials: We administered FGFC and FGF1 intraperitoneally to BALB/c mice 24 h before or after total-body irradiation (TBI). The numbers of surviving crypts were determined 3.5 days after TBI with gamma rays at doses ranging from 8 to 12 Gy. Results: The effect of FGFC was equal to or slightly superior to FGF1 with heparin. However, FGFC was significantly more effective in promoting crypt survival than FGF1 (p < 0.01) when 10 {mu}g of each FGF was administered without heparin before irradiation. In addition, FGFC was significantly more effective at promoting crypt survival (p < 0.05) than FGF1 even when administered without heparin at 24 h after TBI at 10, 11, or 12 Gy. We found that FGFC post treatment significantly promoted 5-bromo-2'-deoxyuridine incorporation into crypts and increased crypt depth, resulting in more epithelial differentiation. However, the number of apoptotic cells in FGFC-treated mice decreased to almost the same level as that in FGF1-treated mice. Conclusions: These findings suggest that FGFC strongly enhanced radioprotection with the induction of epithelial proliferation without exogenous heparin after irradiation and is useful in clinical applications for both the prevention and post treatment of radiation injuries.

  9. Epidermal Growth Factor and Intestinal Barrier Function.

    PubMed

    Tang, Xiaopeng; Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng; Fang, Rejun

    2016-01-01

    Epidermal growth factor (EGF) is a 53-amino acid peptide that plays an important role in regulating cell growth, survival, migration, apoptosis, proliferation, and differentiation. In addition, EGF has been established to be an effective intestinal regulator helping to protect intestinal barrier integrity, which was essential for the absorption of nutrients and health in humans and animals. Several researches have demonstrated that EGF via binding to the EGF receptor and subsequent activation of Ras/MAPK, PI3K/AKT, PLC-γ/PKC, and STATS signal pathways regulates intestinal barrier function. In this review, the relationship between epidermal growth factor and intestinal development and intestinal barrier is described, to provide a better understanding of the effects of EGF on intestine development and health. PMID:27524860

  10. Epidermal Growth Factor and Intestinal Barrier Function

    PubMed Central

    Liu, Hu; Yang, Shufen; Li, Zuohua; Zhong, Jinfeng

    2016-01-01

    Epidermal growth factor (EGF) is a 53-amino acid peptide that plays an important role in regulating cell growth, survival, migration, apoptosis, proliferation, and differentiation. In addition, EGF has been established to be an effective intestinal regulator helping to protect intestinal barrier integrity, which was essential for the absorption of nutrients and health in humans and animals. Several researches have demonstrated that EGF via binding to the EGF receptor and subsequent activation of Ras/MAPK, PI3K/AKT, PLC-γ/PKC, and STATS signal pathways regulates intestinal barrier function. In this review, the relationship between epidermal growth factor and intestinal development and intestinal barrier is described, to provide a better understanding of the effects of EGF on intestine development and health. PMID:27524860

  11. Intratracheal Heparin Improves Plastic Bronchitis Due to Sulfur Mustard Analog

    PubMed Central

    Houin, Paul R.; Veress, Livia A.; Rancourt, Raymond C.; Hendry-Hofer, Tara B.; Loader, Joan E.; Rioux, Jacqueline S.; Garlick, Rhonda B.; White, Carl W.

    2014-01-01

    Summary Background Inhalation of sulfur mustard (SM) and SM analog, 2-chloroethyl ethyl sulfide (CEES), cause fibrinous cast formation that occludes the conducting airways, similar to children with Fontan physiology-induced plastic bronchitis. These airway casts cause significant mortality and morbidity, including hypoxemia and respiratory distress. Our hypothesis was that intratracheal heparin, a highly cost effective and easily preserved rescue therapy, could reverse morbidity and mortality induced by bronchial cast formation. Methods Sprague-Dawley rats were exposed to 7.5% CEES via nose-only aerosol inhalation to produce extensive cast formation and mortality. The rats were distributed into three groups: non-treated, phosphate-buffered saline (PBS)-treated, and heparin-treated groups. Morbidity was assessed with oxygen saturations and clinical distress. Blood and bronchoalveolar lavage fluid (BALF) were obtained for analysis, and lungs were fixed for airway microdissection to quantify the extent of airway cast formation. Results Heparin, given intratracheally improved survival (100%) when compared to non-treated (75%) and PBS-treated (90%) controls. Heparin-treated rats also had improved oxygen saturations, clinical distress and airway cast scores. Heparin-treated rats had increased thrombin clotting times, factor Xa inhibition and activated partial thromboplastin times, indicating systemic absorption of heparin. There were also increased red blood cells (RBCs) in the BALF in 2/6 heparin-treated rats compared to PBS-treated control rats. Conclusions Intratracheal heparin 1 hr after CEES inhalation improved survival, oxygenation, airway obstruction, and clinical distress. There was systemic absorption of heparin in rats treated intratracheally. Some rats had increased RBCs in BALF, suggesting a potential for intrapulmonary bleeding if used chronically after SM inhalation. PMID:24692161

  12. Binding, internalization, and degradation of basic fibroblast growth factor in human microvascular endothelial cells

    SciTech Connect

    Bikfalvi, A.; Dupuy, E.; Inyang, A.L.; Tobelem, G. ); Fayein, N.; Courtois, Y. ); Leseche, G. )

    1989-03-01

    The binding, internalization, and degradation of basic fibroblast growth factor (bFGF) in human omental microvascular endothelial cells (HOME cells) were investigated. Binding studies of bFGF in human endothelial cells have not yet been reported. Basic FGF bound to HOME cells. The number of low-affinity binding sites was found to be variable. Washing the cells with 2 M phosphate-buffered saline removed completely {sup 125}I-bFGF bound to low-affinity binding sites but decreased also the high-affinity binding. The majority of the surface-bound {sup 125}I-bFGF was removed by washing the cells with acetic acid buffer at pH 3. At this temperature, degradation of the internalized ligand was followed after 1 hour by the appearance of three major bands of 15,000 10,000, and 8,000 Da and was inhibited by chloroquine. These results demonstrated two classes of binding sites for bFGF in HOME cells; the number of high-affinity binding sites being larger than the number reported for bovine capillary endothelial cells. The intracellular processing of bFGF in HOME cells seems to be different from that of heparin binding growth factor-1 in murine lung capillary endothelial cells and of eye-derived growth factor-1 in Chinese hamster fibroblasts.

  13. Nerve Growth Factor and Diabetic Neuropathy

    PubMed Central

    Vinik, Aaron

    2003-01-01

    Neuropathy is one of the most debilitating complications of both type 1 and type 2 diabetes, with estimates of prevalence between 50–90% depending on the means of detection. Diabetic neuropathies are heterogeneous and there is variable involvement of large myelinated fibers and small, thinly myelinated fibers. Many of the neuronal abnormalities in diabetes can be duplicated by experimental depletion of specific neurotrophic factors, their receptors or their binding proteins. In experimental models of diabetes there is a reduction in the availability of these growth factors, which may be a consequence of metabolic abnormalities, or may be independent of glycemic control. These neurotrophic factors are required for the maintenance of the neurons, the ability to resist apoptosis and regenerative capacity. The best studied of the neurotrophic factors is nerve growth factor (NGF) and the related members of the neurotrophin family of peptides. There is increasing evidence that there is a deficiency of NGF in diabetes, as well as the dependent neuropeptides substance P (SP) and calcitonin gene-related peptide (CGRP) that may also contribute to the clinical symptoms resulting from small fiber dysfunction. Similarly, NT3 appears to be important for large fiber and IGFs for autonomic neuropathy. Whether the observed growth factor deficiencies are due to decreased synthesis, or functional, e.g. an inability to bind to their receptor, and/or abnormalities in nerve transport and processing, remains to be established. Although early studies in humans on the role of neurotrophic factors as a therapy for diabetic neuropathy have been unsuccessful, newer agents and the possibilities uncovered by further studies should fuel clinical trials for several generations. It seems reasonable to anticipate that neurotrophic factor therapy, specifically targeted at different nerve fiber populations, might enter the therapeutic armamentarium. PMID:14668049

  14. Transforming growth factor alpha and epidermal growth factor levels in bladder cancer and their relationship to epidermal growth factor receptor.

    PubMed Central

    Mellon, J. K.; Cook, S.; Chambers, P.; Neal, D. E.

    1996-01-01

    We have examined levels of epidermal growth factor (EGF) and transforming growth factor alpha (TGF-alpha) in neoplastic and non-neoplastic bladder tissue using a standard radioimmunoassay technique. Tumour samples had much higher TGF-alpha levels compared with EGF and TGF-alpha levels in malignant tissue were significantly higher than in benign bladder samples. There was, in addition, a difference in mean EGF levels from 'normal' bladder samples from non-tumour bearing areas of bladder in patients with bladder cancer compared with 'normal' bladder tissue obtained at the time of organ retrieval surgery. Levels of EGF and TGF-alpha did not correlate with levels of EGF receptor (EGFR) as determined by a radioligand binding method but levels of TGF-alpha > 10 ng gm-1 of tumour tissue did correlate with EGFR positivity defined using immunohistochemistry. These data suggest that TGF-alpha is the likely ligand for EGFR in bladder tumours. PMID:8605103

  15. Growth Factors and Tension-Induced Skeletal Muscle Growth

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman H.

    1994-01-01

    The project investigated biochemical mechanisms to enhance skeletal muscle growth, and developed a computer based mechanical cell stimulator system. The biochemicals investigated in this study were insulin/(Insulin like Growth Factor) IGF-1 and Steroids. In order to analyze which growth factors are essential for stretch-induced muscle growth in vitro, we developed a defined, serum-free medium in which the differentiated, cultured avian muscle fibers could be maintained for extended periods of time. The defined medium (muscle maintenance medium, MM medium) maintains the nitrogen balance of the myofibers for 3 to 7 days, based on myofiber diameter measurements and myosin heavy chain content. Insulin and IGF-1, but not IGF-2, induced pronounced myofiber hypertrophy when added to this medium. In 5 to 7 days, muscle fiber diameters increase by 71 % to 98% compared to untreated controls. Mechanical stimulation of the avian muscle fibers in MM medium increased the sensitivity of the cells to insulin and IGF-1, based on a leftward shift of the insulin dose/response curve for protein synthesis rates. (54). We developed a ligand binding assay for IGF-1 binding proteins and found that the avian skeletal muscle cultures produced three major species of 31, 36 and 43 kD molecular weight (54) Stretch of the myofibers was found to have no significant effect on the efflux of IGF-1 binding proteins, but addition of exogenous collagen stimulated IGF-1 binding protein production 1.5 to 5 fold. Steroid hormones have a profound effect on muscle protein turnover rates in vivo, with the stress-related glucocorticoids inducing rapid skeletal muscle atrophy while androgenic steroids induce skeletal muscle growth. Exercise in humans and animals reduces the catabolic effects of glucocorticoids and may enhance the anabolic effects of androgenic steroids on skeletal muscle. In our continuing work on the involvement of exogenrus growth factors in stretch-induced avian skeletal muscle growth, we

  16. Growth hormone, insulin-like growth factor system and carcinogenesis.

    PubMed

    Boguszewski, Cesar Luiz; Boguszewski, Margaret Cristina da Silva; Kopchick, John J

    2016-01-01

    The growth hormone (GH) and insulin-like growth factor (IGF) system plays an important role in the regulation of cell proliferation, differentiation, apoptosis, and angiogenesis. In terms of cell cycle regulation, the GH-IGF system induces signalling pathways for cell growth that compete with other signalling systems that result in cell death; thus the final effect of these opposed forces is critical for normal and abnormal cell growth. The association of the GH-IGF system with carcinogenesis has long been hypothesised, mainly based on in vitro studies and the use of a variety of animal models of human cancer, and also on epidemiological and clinical evidence in humans. While ample experimental evidence supports a role of the GH-IGF system in tumour promotion and progression, with several of its components being currently tested as central targets for cancer therapy, the strength of evidence from patients with acromegaly, GH deficiency, or treated with GH is much weaker. In this review, we will attempt to consolidate this data. (Endokrynol Pol 2016; 67 (4): 414-426). PMID:27387246

  17. Growth hormone-insulinlike growth factor I and immune function.

    PubMed

    Gelato, M C

    1993-04-01

    Growth hormone (GH) and insulinlike growth factor I (IGF-I) may be part of a neuroendocrine immune axis that stimulates cellular proliferation of primary lymphoid organs (bone marrow, thymus) as well as stimulates activation of peripheral lymphocytes and macrophages to enhance specific immune responses. GH can also stimulate production of thymic hormones and cytokines, and in this way impact on immune function. It is not clear whether GH and IGF-I act independently or whether the action of GH is mediated by local production of IGF-I by lymphocytes. Both GH and IGF-I and their receptors are present in lymphocytes. Thus, cells of the immune system may be important targets of the GH-IGF-I axis. PMID:18407143

  18. Growth Factors and Astrocytes Metabolism: Possible Roles for Platelet Derived Growth Factor.

    PubMed

    Cabezas, Ricardo; Avila-Rodriguez, Marco; Vega-Vela, Nelson E; Echeverria, Valentina; González, Janneth; Hidalgo, Oscar A; Santos, Altair B; Aliev, Gjumrakch; Barreto, George E

    2016-01-01

    Astrocytes exert multiple functions in the brain such as the development of blood-brain barrier characteristics, the promotion of neurovascular coupling, attraction of cells through the release of chemokines, clearance of toxic substances and generation of antioxidant molecules and growth factors. In this aspect, astrocytes secrete several growth factors (BDNF, GDNF, NGF, and others) that are fundamental for cell viability, oxidant protection, genetic expression and modulation of metabolic functions. The platelet derived growth factor (PDGF), which is expressed by many SNC cells, including astrocytes, is an important molecule that has shown neuroprotective potential, improvement of wound healing, regulation of calcium metabolism and mitochondrial function. Here we explore some of these astrocyte-driven functions of growth factors and their possible therapeutic uses in the context of neurodegeneration. PMID:26477707

  19. Effect of heparin on the biological properties and molecular signature of human mesenchymal stem cells.

    PubMed

    Ling, Ling; Camilleri, Emily T; Helledie, Torben; Samsonraj, Rebekah M; Titmarsh, Drew M; Chua, Ren Jie; Dreesen, Oliver; Dombrowski, Christian; Rider, David A; Galindo, Mario; Lee, Ian; Hong, Wanjin; Hui, James H; Nurcombe, Victor; van Wijnen, Andre J; Cool, Simon M

    2016-01-15

    Chronic use of heparin as an anti-coagulant for the treatment of thrombosis or embolism invokes many adverse systemic events including thrombocytopenia, vascular reactions and osteoporosis. Here, we addressed whether adverse effects might also be directed to mesenchymal stem cells that reside in the bone marrow compartment. Harvested human bone marrow-derived mesenchymal stem cells (hMSCs) were exposed to varying doses of heparin and their responses profiled. At low doses (<200 ng/ml), serial passaging with heparin exerted a variable effect on hMSC proliferation and multipotentiality across multiple donors, while at higher doses (≥ 100 μg/ml), heparin supplementation inhibited cell growth and increased both senescence and cell size. Gene expression profiling using cDNA arrays and RNA-seq analysis revealed pleiotropic effects of low-dose heparin on signaling pathways essential to hMSC growth and differentiation (including the TGFβ/BMP superfamily, FGFs, and Wnts). Cells serially passaged in low-dose heparin possess a donor-dependent gene signature that reflects their altered phenotype. Our data indicate that heparin supplementation during the culturing of hMSCs can alter their biological properties, even at low doses. This warrants caution in the application of heparin as a culture supplement for the ex vivo expansion of hMSCs. It also highlights the need for careful evaluation of the bone marrow compartment in patients receiving chronic heparin treatment. PMID:26484394

  20. Non-coding Double-stranded RNA and Antimicrobial Peptide LL-37 Induce Growth Factor Expression from Keratinocytes and Endothelial Cells.

    PubMed

    Adase, Christopher A; Borkowski, Andrew W; Zhang, Ling-Juan; Williams, Michael R; Sato, Emi; Sanford, James A; Gallo, Richard L

    2016-05-27

    A critical function for skin is that when damaged it must simultaneously identify the nature of the injury, repair barrier function, and limit the intrusion of pathogenic organisms. These needs are carried out through the detection of damage-associated molecular patterns (DAMPs) and a response that includes secretion of cytokines, chemokines, growth factors, and antimicrobial peptides (AMPs). In this study, we analyzed how non-coding double-stranded RNA (dsRNAs) act as a DAMP in the skin and how the human cathelicidin AMP LL-37 might influence growth factor production in response to this DAMP. dsRNA alone significantly increased the expression of multiple growth factors in keratinocytes, endothelial cells, and fibroblasts. Furthermore, RNA sequencing transcriptome analysis found that multiple growth factors increase when cells are exposed to both LL-37 and dsRNA, a condition that mimics normal wounding. Quantitative PCR and/or ELISA validated that growth factors expressed by keratinocytes in these conditions included, but were not limited to, basic fibroblast growth factor (FGF2), heparin-binding EGF-like growth factor (HBEGF), vascular endothelial growth factor C (VEGFC), betacellulin (BTC), EGF, epiregulin (EREG), and other members of the transforming growth factor β superfamily. These results identify a novel role for DAMPs and AMPs in the stimulation of repair and highlight the complex interactions involved in the wound environment. PMID:27048655

  1. Immobilization of Heparin: Approaches and Applications

    PubMed Central

    Murugesan, Saravanababu; Xie, Jin; Linhardt, Robert J.

    2014-01-01

    Heparin, an anticoagulant, has been used in many forms to treat various diseases. These forms include soluble heparin and heparin immobilized to supporting matrices by physical adsorption, by covalent chemical methods and by photochemical attachment. These immobilization methods often require the use of spacers or linkers. This review examines and compares various techniques that have been used for the immobilization of heparin as well as applications of these immobilized heparins. In the applications reviewed, immobilized heparin is compared with soluble heparin for efficient and versatile use in each of the various applications. PMID:18289079

  2. Growth Hormone and Insulin-Like Growth Factor-1.

    PubMed

    Nicholls, Adam R; Holt, Richard I G

    2016-01-01

    Human growth hormone (GH) was first isolated from the human pituitary gland in 1945 and found to promote the growth of children with hypopituitarism. Since the formation of the World Anti-Doping Association, human GH has appeared on the list of forbidden substances. There is a significant amount of anecdotal evidence that human GH is misused by athletes to enhance performance, and there have been a number of high-profile cases of GH use in professional sport. GH secretagogues (GH-Ss), which increase GH secretion, and insulin-like growth factor (IGF-1), which mediates many of the effects of GH, are also misused, although there is less evidence for this. The effectiveness of GH, IGF-1, and GH-Ss as performance-enhancing drugs remains unclear. Evidence from studies of GH use in people with hypopituitarism show several desirable outcomes, including increased lean body mass, increased strength, and increased exercise capacity. These anabolic and metabolic properties, coupled with the difficulty in detecting them, make them attractive as agents of misuse. Studies in healthy young adults have also demonstrated a performance benefit with GH and IGF-1. PMID:27347885

  3. Structural Snapshots of Heparin Depolymerization by Heparin Lyase I

    SciTech Connect

    Han, Young-Hyun; Garron, Marie-Line; Kim, Hye-Yeon; Kim, Wan-Seok; Zhang, Zhenqing; Ryu, Kyeong-Seok; Shaya, David; Xiao, Zhongping; Cheong, Chaejoon; Kim, Yeong Shik; Linhardt, Robert J.; Jeon, Young Ho; Cygler, Miroslaw

    2010-01-12

    Heparin lyase I (heparinase I) specifically depolymerizes heparin, cleaving the glycosidic linkage next to iduronic acid. Here, we show the crystal structures of heparinase I from Bacteroides thetaiotaomicron at various stages of the reaction with heparin oligosaccharides before and just after cleavage and product disaccharide. The heparinase I structure is comprised of a {beta}-jellyroll domain harboring a long and deep substrate binding groove and an unusual thumb-resembling extension. This thumb, decorated with many basic residues, is of particular importance in activity especially on short heparin oligosaccharides. Unexpected structural similarity of the active site to that of heparinase II with an ({alpha}/{alpha}){sub 6} fold is observed. Mutational studies and kinetic analysis of this enzyme provide insights into the catalytic mechanism, the substrate recognition, and processivity.

  4. Waste management - cytokines, growth factors and cachexia.

    PubMed

    Saini, Amarjit; Al-Shanti, Nasser; Nasser, Al-Shanti; Stewart, Claire E H

    2006-12-01

    Muscle damage with a lack of regeneration, manifests itself in several life-threatening diseases, including cancer cachexia, congestive heart failure, AIDS and sepsis. Often misdiagnosed as a condition simply of weight loss, cachexia is actually a highly complex metabolic disorder involving features of anorexia, anaemia, lipolysis and insulin resistance. A significant loss of lean body mass arises from such conditions, resulting in wasting of skeletal muscle. Unlike starvation, the weight loss seen in chronic illnesses arises equally from loss of muscle and of fat. The cachectic state is particularly problematic in cancer, typifying poor prognosis and often lowering responses to chemotherapy and radiation treatment. More than half of cancer patients suffer from cachexia, and strikingly, nearly one-third of cancer deaths are related to cachexia rather than the tumour burden. In considering this disorder, we are faced with a conundrum; how is it possible for uncontrolled growth to prevail in the tumour, in the face of unrestrained tissue loss in our muscles? Consistently, the catabolic state has been associated with a shift in the homeostatic balance between muscle synthesis and degradation mediated by the actions of growth factors and cytokines. Indeed, tumour necrosis factor-alpha (TNF-alpha) levels are raised in several animal models of cachectic muscle wasting, whereas the insulin-like growth factor (IGF) system acts potently to regulate muscle development, hypertrophy and maintenance. This concept of skeletal muscle homeostasis, often viewed as the net balance between two separate processes of protein synthesis and degradation has however changed. More recently, the view is that these two biochemical processes are not occurring independently of each other but in fact are finely co-ordinated by a web of intricate signalling networks. This review, therefore, aims to discuss data currently available regarding the mechanisms of degeneration and regeneration with

  5. Fluid flow releases fibroblast growth factor-2 from human aortic smooth muscle cells

    NASA Technical Reports Server (NTRS)

    Rhoads, D. N.; Eskin, S. G.; McIntire, L. V.

    2000-01-01

    This study tested the hypothesis that fluid shear stress regulates the release of fibroblast growth factor (FGF)-2 from human aortic smooth muscle cells. FGF-2 is a potent mitogen that is involved in the response to vascular injury and is expressed in a wide variety of cell types. FGF-2 is found in the cytoplasm of cells and outside cells, where it associates with extracellular proteoglycans. To test the hypothesis that shear stress regulates FGF-2 release, cells were exposed to flow, and FGF-2 amounts were measured from the conditioned medium, pericellular fraction (extracted by heparin treatment), and cell lysate. Results from the present study show that after 15 minutes of shear stress at 25 dyne/cm(2) in a parallel-plate flow system, a small but significant fraction (17%) of the total FGF-2 was released from human aortic smooth muscle cells. FGF-2 levels in the circulating medium increased 10-fold over medium from static controls (P<0.01). A 50% increase in FGF-2 content versus control (P<0.01) was found in the pericellular fraction (extracted by heparin treatment). Furthermore, a significant decrease in FGF-2 was detected in the cell lysate, indicating that FGF-2 was released from inside the cell. Cell permeability studies with fluorescent dextran were performed to examine whether transient membrane disruption caused FGF-2 release. Flow cytometry detected a 50% increase in mean fluorescence of cells exposed to 25 dyne/cm(2) versus control cells. This indicates that the observed FGF-2 release from human aortic smooth muscle cells is likely due to transient membrane disruption on initiation of flow.

  6. Molecular basis for the Kallmann syndrome-linked fibroblast growth factor receptor mutation

    SciTech Connect

    Thurman, Ryan D.; Kathir, Karuppanan Muthusamy; Rajalingam, Dakshinamurthy; Kumar, Thallapuranam K. Suresh

    2012-08-31

    Highlights: Black-Right-Pointing-Pointer The structural basis of the Kallmann syndrome is elucidated. Black-Right-Pointing-Pointer Kallmann syndrome mutation (A168S) induces a subtle conformational change(s). Black-Right-Pointing-Pointer Structural interactions mediated by beta-sheet G are most perturbed. Black-Right-Pointing-Pointer Ligand (FGF)-receptor interaction(s) is completely abolished by Kallmann mutation. Black-Right-Pointing-Pointer Kallmann mutation directly affects the FGF signaling process. -- Abstract: Kallmann syndrome (KS) is a developmental disease that expresses in patients as hypogonadotropic hypogonadism and anosmia. KS is commonly associated with mutations in the extracellular D2 domain of the fibroblast growth factor receptor (FGFR). In this study, for the first time, the molecular basis for the FGFR associated KS mutation (A168S) is elucidated using a variety of biophysical experiments, including multidimensional NMR spectroscopy. Secondary and tertiary structural analysis using far UV circular dichroism, fluorescence and limited trypsin digestion assays suggest that the KS mutation induces subtle tertiary structure change in the D2 domain of FGFR. Results of isothermal titration calorimetry experiments show the KS mutation causes a 10-fold decrease in heparin binding affinity and also a complete loss in ligand (FGF-1) binding. {sup 1}H-{sup 15}N chemical perturbation data suggest that complete loss in the ligand (FGF) binding affinity is triggered by a subtle conformational change that disrupts crucial structural interactions in both the heparin and the FGF binding sites in the D2 domain of FGFR. The novel findings reported in this study are expected to provide valuable clues toward a complete understanding of the other genetic diseases linked to mutations in the FGFR.

  7. The Role of Endogenous Epidermal Growth Factor Receptor Ligands in Mediating Corneal Epithelial Homeostasis

    PubMed Central

    Peterson, Joanne L.; Phelps, Eric D.; Doll, Mark A.; Schaal, Shlomit; Ceresa, Brian P.

    2014-01-01

    Purpose. To provide a comprehensive study of the biological role and therapeutic potential of six endogenous epidermal growth factor receptor (EGFR) ligands in corneal epithelial homeostasis. Methods. Kinetic analysis and dose response curves were performed by using in vitro and in vivo wound-healing assays. Biochemical assays were used to determine receptor expression and activity. Human tears were collected and quantitatively analyzed by multianalyte profiling for endogenous EGFR ligands. Results. Epidermal growth factor receptor ligands improved wound closure and activated EGFR, but betacellulin (BTC) was the most efficacious promoter of wound healing in vitro. In contrast, only epidermal growth factor (EGF) promoted wound healing in vivo. Human tears from 25 healthy individuals showed EGFR ligands at these average concentrations: EGF at 2053 ± 312.4 pg/mL, BTC at 207 ± 39.4 pg/mL, heparin-binding EGF at 44 ± 5.8 pg/mL, amphiregulin at 509 ± 28.8 pg/mL, transforming growth factor-α at 84 ± 19 pg/mL, and epiregulin at 52 ± 15 pg/mL. Conclusions. Under unwounded conditions, only EGF was present at concentrations near the ligand's Kd for the receptor, indicating it is the primary mediator of corneal epithelial homeostasis. Other ligands were present but at concentrations 11- to 7500-fold less their Kd, preventing significant ligand binding. Further, the high levels of EGF and its predicted binding preclude receptor occupancy by exogenous ligand and can explain the discrepancy between the in vitro and in vivo data. Therefore, therapeutic use of EGFR ligands may be unpredictable and impractical. PMID:24722692

  8. Heparin Characterization: Challenges and Solutions

    NASA Astrophysics Data System (ADS)

    Jones, Christopher J.; Beni, Szabolcs; Limtiaco, John F. K.; Langeslay, Derek J.; Larive, Cynthia K.

    2011-07-01

    Although heparin is an important and widely prescribed pharmaceutical anticoagulant, its high degree of sequence microheterogeneity and size polydispersity make molecular-level characterization challenging. Unlike nucleic acids and proteins that are biosynthesized through template-driven assembly processes, heparin and the related glycosaminoglycan heparan sulfate are actively remodeled during biosynthesis through a series of enzymatic reactions that lead to variable levels of O- and N-sulfonation and uronic acid epimers. As summarized in this review, heparin sequence information is determined through a bottom-up approach that relies on depolymerization reactions, size- and charge-based separations, and sensitive mass spectrometric and nuclear magnetic resonance experiments to determine the structural identity of component oligosaccharides. The structure-elucidation process, along with its challenges and opportunities for future analytical improvements, is reviewed and illustrated for a heparin-derived hexasaccharide.

  9. Disruption of cell-matrix interactions by heparin enhances mesenchymal progenitor adipocyte differentiation

    SciTech Connect

    Luo Weijun; Shitaye, Hailu; Friedman, Michael; Bennett, Christina N.; Miller, Joshua; MacDougald, Ormond A.; Hankenson, Kurt D.

    2008-11-01

    Differentiation of marrow-derived mesenchymal progenitors to either the osteoblast or adipocyte lineage is reciprocally regulated. Factors that promote osteoblastogenesis inhibit adipogenesis, while adipogenic factors are inhibitory to osteoblast differentiation. Heparin, a soluble glycosaminoglycan, inhibits bone formation in vivo and osteoblast cell differentiation and function in vitro, and has been shown to promote adipocyte differentiation. To elucidate the role that heparin plays in the adipogenic induction of murine mesenchymal progenitors, we studied immortalized marrow stromal cells (IM-MSC), the MSC cell line, ST2, and 3T3L1 pre-adipocytes. Heparin alone was not sufficient to induce adipogenesis, but enhanced the induction under a variety of adipogenic cocktails. This effect was both dose- and time-dependent. Heparin showed a positive effect at concentrations > 0. 1 {mu}g/ml when applied before day 3 during the induction course. Heparin's effect on adipogenesis was independent of cell proliferation, cell density, and extracellular lipid. This effect is likely related to the unique structure of heparin because another polyanionic glycosaminoglycan, dextran sulfate, did not promote adipogenic differentiation. Heparin treatment altered morphology and adhesion characteristics of progenitor cells, resulting in cell rounding and aggregation. As well, heparin counteracted the known inhibitory effect of fibronectin on adipogenesis and decreased basal focal adhesion kinase and paxillin phosphorylation. We conclude that heparin-mediated disruption of cell-matrix adhesion enhances adipogenic potential.

  10. Expression of the vascular endothelial growth factor receptor, KDR, in human placenta.

    PubMed Central

    Vuckovic, M; Ponting, J; Terman, B I; Niketic, V; Seif, M W; Kumar, S

    1996-01-01

    Vascular endothelial growth factor (VEGF) is a heparin-binding growth factor known to act directly on vascular endothelial cells by promoting cell proliferation and permeability. To date, 3 structurally related cell surface receptors for VEGF, Flt-1, Flt-4 and KDR, have been identified and shown to be human type III receptor tyrosine kinases. The establishment of a vascular network is crucial to the development of the placenta and occurs through both angiogenesis and vasculogenesis. The signals controlling these processes are unclear. Immunohistochemical and in situ hybridisation techniques have localised VEGF in the trophoblast layers and VEGF binding to placental vascular endothelial cells and haemangioblasts has been shown, suggesting a role for VEGF and its receptors in development of the vascular network. In this study we have used specific antibodies to localise KDR and endothelial cells in 1st and 3rd trimester human placenta. The staining showed a colocalisation of KDR with endothelial cells and haemangioblasts. No staining of trophoblast cells was observed, but strong staining of the endothelial cells was seen in the villous stroma adjacent to areas of trophoblast proliferation. Images Fig. 1 Fig. 2 PMID:8621335

  11. Vascular endothelial growth factor from Trimeresurus jerdonii venom specifically binds to VEGFR-2.

    PubMed

    Zhong, Shurong; Wu, Jianbo; Cui, Yunpeng; Li, Rui; Zhu, Shaowen; Rong, Mingqiang; Lu, Qiumin; Lai, Ren

    2015-09-01

    Vascular endothelial growth factors (VEGFs) play important roles in angiogenesis. In this study, a vascular endothelial growth factor named TjsvVEGF was purified from the venom of Trimeresurus jerdonii by gel filtration, affinity, ion-exchange and high-performance liquid chromatography. TjsvVEGF was a homodimer with an apparent molecular mass of 29 kDa. The cDNA encoding TjsvVEGF was obtained by PCR. The open reading frame of the cloned TjsvVEGF was composed of 432 bp coding for a signal peptide of 24 amino acid residues and a mature protein of 119 amino acid residues. Compared with other snake venom VEGFs, the nucleotide and deduced protein sequences of the cloned TjsvVEGF were conserved. TjsvVEGF showed low heparin binding activity and strong capillary permeability increasing activity. The KD of TjsvVEGF to VEFGR-2 is 413 pM. However, the binding of TjsvVEGF to VEGFR-1 is too weak to detect. Though TjsvVEGF had high sequence identities (about 90%) with Crotalinae VEGFs, the receptor preference of TjsvVEGF was similar to Viperinae VEGFs which had lower sequence identities (about 60%) with it. TjsvVEGF might serve as a useful tool for the study of structure-function relationships of VEGFs and their receptors. PMID:26107411

  12. Bioengineered heparins and heparan sulfates.

    PubMed

    Fu, Li; Suflita, Matthew; Linhardt, Robert J

    2016-02-01

    Heparin and heparan sulfates are closely related linear anionic polysaccharides, called glycosaminoglycans, which exhibit a number of important biological and pharmacological activities. These polysaccharides, having complex structures and polydispersity, are biosynthesized in the Golgi of animal cells. While heparan sulfate is a widely distributed membrane and extracellular glycosaminoglycan, heparin is found primarily intracellularly in the granules of mast cells. While heparin has historically received most of the scientific attention for its anticoagulant activity, interest has steadily grown in the multi-faceted role heparan sulfate plays in normal and pathophysiology. The chemical synthesis of these glycosaminoglycans is largely precluded by their structural complexity. Today, we depend on livestock animal tissues for the isolation and the annual commercial production of hundred ton quantities of heparin used in the manufacture of anticoagulant drugs and medical device coatings. The variability of animal-sourced heparin and heparan sulfates, their inherent impurities, the limited availability of source tissues, the poor control of these source materials and their manufacturing processes, suggest a need for new approaches for their production. Over the past decade there have been major efforts in the biotechnological production of these glycosaminoglycans, driven by both therapeutic applications and as probes to study their natural functions. This review focuses on the complex biology of these glycosaminoglycans in human health and disease, and the use of recombinant technology in the chemoenzymatic synthesis and metabolic engineering of heparin and heparan sulfates. PMID:26555370

  13. Decorin: A Growth Factor Antagonist for Tumor Growth Inhibition

    PubMed Central

    Järvinen, Tero A. H.; Prince, Stuart

    2015-01-01

    Decorin (DCN) is the best characterized member of the extracellular small leucine-rich proteoglycan family present in connective tissues, typically in association with or “decorating” collagen fibrils. It has substantial interest to clinical medicine owing to its antifibrotic, anti-inflammatory, and anticancer effects. Studies on DCN knockout mice have established that a lack of DCN is permissive for tumor development and it is regarded as a tumor suppressor gene. A reduced expression or a total disappearance of DCN has been reported to take place in various forms of human cancers during tumor progression. Furthermore, when used as a therapeutic molecule, DCN has been shown to inhibit tumor progression and metastases in experimental cancer models. DCN affects the biology of various types of cancer by targeting a number of crucial signaling molecules involved in cell growth, survival, metastasis, and angiogenesis. The active sites for the neutralization of different growth factors all reside in different parts of the DCN molecule. An emerging concept that multiple proteases, especially those produced by inflammatory cells, are capable of cleaving DCN suggests that native DCN could be inactivated in a number of pathological inflammatory conditions. In this paper, we review the role of DCN in cancer. PMID:26697491

  14. Customized Ca–P/PHBV nanocomposite scaffolds for bone tissue engineering: design, fabrication, surface modification and sustained release of growth factor

    PubMed Central

    Duan, Bin; Wang, Min

    2010-01-01

    Integrating an advanced manufacturing technique, nanocomposite material and controlled delivery of growth factor to form multifunctional tissue engineering scaffolds was investigated in this study. Based on calcium phosphate (Ca–P)/poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) nanocomposite microspheres, three-dimensional Ca–P/PHBV nanocomposite scaffolds with customized architecture, controlled porosity and totally interconnected porous structure were successfully fabricated using selective laser sintering (SLS), one of the rapid prototyping technologies. The cytocompatibility of sintered Ca–P/PHBV nanocomposite scaffolds, as well as PHBV polymer scaffolds, was studied. For surface modification of nanocomposite scaffolds, gelatin was firstly physically entrapped onto the scaffold surface and heparin was subsequently immobilized on entrapped gelatin. The surface-modification improved the wettability of scaffolds and provided specific binding site between conjugated heparin and the growth factor recombinant human bone morphogenetic protein-2 (rhBMP-2). The surface-modified Ca–P/PHBV nanocomposite scaffolds loaded with rhBMP-2 significantly enhanced the alkaline phosphatase activity and osteogenic differentiation markers in gene expression of C3H10T1/2 mesenchymal stem cells. Together with osteoconductive nanocomposite material and controlled growth factor delivery strategies, the use of SLS technique to form complex scaffolds will provide a promising route towards individualized bone tissue regeneration. PMID:20504805

  15. Further insights into the anti-PF4/heparin IgM immune response.

    PubMed

    Krauel, Krystin; Schulze, Annika; Jouni, Rabie; Hackbarth, Christine; Hietkamp, Bernhard; Selleng, Sixten; Koster, Andreas; Jensch, Inga; van der Linde, Julia; Schwertz, Hansjörg; Bakchoul, Tamam; Hundt, Matthias; Greinacher, Andreas

    2016-04-01

    Anti-platelet factor 4 (PF4)/heparin antibodies are not only the cause of heparin-induced thrombocytopenia but might also play a role in the antibacterial host defence. Recently, marginal zone (MZ) B cells were identified to be crucial for anti-PF4/heparin IgG antibody production in mice. Combining human studies and a murine model of polymicrobial sepsis we further characterised the far less investigated anti-PF4/heparin IgM immune response. We detected anti-PF4/heparin IgM antibodies in the sera of paediatric patients < 6 months of age after cardiac surgery and in sera of splenectomised mice subjected to polymicrobial sepsis. In addition, PF4/heparin-specific IgM B cells were not only found in murine spleen, but also in peritoneum and bone marrow upon in vitro stimulation. Together, this indicates involvement of additional B cell populations, as MZ B cells are not fully developed in humans until the second year of life and are restricted to the spleen in mice. Moreover, PF4/heparin-specific B cells were detected in human cord blood upon in vitro stimulation and PF4-/- mice produced anti-PF4/heparin IgM antibodies after polymicrobial sepsis. In conclusion, the anti-PF4/heparin IgM response is a potential innate immune reaction driven by a B cell population distinct from MZ B cells. PMID:26467272

  16. Enhanced regenerative healing efficacy of a highly skin-permeable growth factor nanocomplex in a full-thickness excisional mouse wound model

    PubMed Central

    Bae, Il-Hong; Park, Jin Woo; Kim, Dae-Yong

    2014-01-01

    Exogenous administration of growth factors has potential benefits in wound healing; however, limited percutaneous absorption, inconsistent efficacy, and the need for high doses have hampered successful clinical use. To overcome these restrictions, we focused on the development of a topical formulation composed of highly skin-permeable multimeric nanocomplex of growth factors. In the present study, we fused low-molecular-weight protamine (LMWP) with epidermal growth factor (EGF), insulin-like growth factor 1 (IGF-I), and platelet-derived growth factor A ligand (PDGF-A) (producing recombinant [r]LMWP-EGF, rLMWP-IGF-I, and rLMWP-PDGF-A, respectively) via genetic modification. Then, we used in vitro cell proliferation studies to assess the biological activity and the benefits of the combination. The LMWP-conjugated growth factors were complexed with low-molecular-weight heparin (LMWH) and formulated with Poloxamer 188 as a delivery vehicle. After confirming the enhanced skin permeability, in vivo studies were performed to assess whether the LMWP-conjugated growth factor nanocomplex formulations accelerated the healing of full-thickness wounds in mice. The LMWP-conjugated growth factors were biologically equivalent to their native forms, and their combination induced greater fibroblast proliferation. rLMWP-EGF showed significantly enhanced permeability and cumulative permeation, and the rates for rLMWP-IGF-I and rLMWP-PDGF-A, across excised mouse skin, were 124% and 164% higher, respectively, than for the native forms. The LMWP-fused growth factors resulted in formation of nanocomplexes (23.51±1.12 nm in diameter) in combination with LMWH. Topical delivery of growth factors fused with LMWP accelerated wound re-epithelialization significantly, accompanied by the formation of healthy granulation tissue within 9 days compared with a free–growth factor complex or vehicle. Thus, the LMWP-conjugated growth factor nanocomplex can induce rapid, comprehensive healing and may

  17. Characterization of insulin-like growth factor I and epidermal growth factor receptors in meningioma

    SciTech Connect

    Kurihara, M.; Tokunaga, Y.; Tsutsumi, K.; Kawaguchi, T.; Shigematsu, K.; Niwa, M.; Mori, K. )

    1989-10-01

    Receptors for insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) were localized and characterized in eight samples of human meningioma (four fibrous, two meningothelial, and two angioblastic types), using quantitative autoradiographic techniques. Effects of both growth factors on deoxyribonucleic acid (DNA) synthesis in the cultured meningioma cells were examined. High numbers of specific binding sites for both IGF-I and EGF were homogeneously present in tissue sections derived from fibrous and meningothelial types of meningiomas, whereas binding sites for these growth factors were not detectable in adjacent leptomeninges. While relatively large numbers of IGF-I binding sites were located in the wall of the intratumoral vasculature, the number of binding sites in the stromal component was lower in angioblastic-type meningiomas, including a low number of EGF binding sites detected only in the stromal portion. Scatchard analysis revealed the presence of a single class of high-affinity binding sites for both IGF-I and EGF in the meningiomas examined (dissociation constant (Kd) = 0.6 to 2.9 nM, and the maximum number of binding sites (Bmax) = 16 to 80 fmol/mg for IGF-I; and Kd = 0.6 to 4.0 nM, Bmax = 3 to 39 fmol/mg for EGF). Both growth factors increased the synthesis of DNA, in a dose-dependent manner, as measured by 3H-thymidine incorporation. The combination of IGF-I and EGF synergistically stimulated the synthesis of DNA, and the effects seen with 10% fetal bovine serum could be reproduced at a concentration of 10(-10) M. These observations can be interpreted to mean that both IGF-I and EGF may be involved in the growth modulation of meningiomas, possibly through paracrine or autocrine mechanisms.

  18. Heparin induced thrombocytopenia management with bivalirudin.

    PubMed

    Meera, R; Rachel, D; Ramakrishnapillai, V; Vijayaraghavan, G

    2007-01-01

    We report a case of Heparin Induced Thrombocytopenia (HIT) following percutaneous coronary intervention. The case is unique in that thrombocytopenia occurred very early after heparin administration and responded well to a regime of bivalirudin-a direct thrombin inhibitor readily available in India. Heparin, Thrombocytopenia, Bivalirudin Acute HIT, occurring within few hours of heparin therapy have been reported in patients previously exposed to unfractionated heparin (UFH) or low molecular weight heparin (LMWH) 1. Prompt recognition of the condition and timely intervention with direct thrombin inhibitors, can result in salvaging patients from this potentially fatal complication. PMID:19126942

  19. Entrapment of basic fibroblast growth factor (bFGF) in a succinylated chitosan nanoparticle delivery system and release profile.

    PubMed

    Butko, Alison; Bonat Celli, Giovana; Paulson, Allan; Ghanem, Amyl

    2016-07-01

    Basic fibroblast growth factor (bFGF) helps to regulate the proliferation and migration of fibroblasts, the proliferation of endothelial cells, and aids the development of angiogenesis. Its in vivo half-life is on the order of minutes due to extensive degradation and inactivation, which could be potentially reduced by controlled release vehicles. In this study, bFGF was entrapped into chitosan (CS) and N-succinyl-chitosan (SC) nanoparticles, with and without heparin, at two levels of initial loading, followed by further characterization of the particles. Release studies were conducted using radiolabeled bFGF-loaded nanoparticles. Both types of nanoparticles loaded similar amounts of bFGF (60.2 and 68.6% for CS and SC, respectively). The release profile varied greatly among the samples, and a burst release was observed in most cases, with the release amount approaching its final value in the first 6 h. The final amount released varied from 1.5 to 18% of the amount of bFGF-entrapped. The concomitant encapsulation of heparin and the use of SC as a nanoparticle matrix contributed to the largest amount of bFGF release (18%) over the time investigated. PMID:27146359

  20. Fibroblast growth factor 23 and bone mineralisation

    PubMed Central

    Guo, Yu-Chen; Yuan, Quan

    2015-01-01

    Fibroblast growth factor 23 (FGF23) is a hormone that is mainly secreted by osteocytes and osteoblasts in bone. The critical role of FGF23 in mineral ion homeostasis was first identified in human genetic and acquired rachitic diseases and has been further characterised in animal models. Recent studies have revealed that the levels of FGF23 increase significantly at the very early stages of chronic kidney disease (CKD) and may play a critical role in mineral ion disorders and bone metabolism in these patients. Our recent publications have also shown that FGF23 and its cofactor, Klotho, may play an independent role in directly regulating bone mineralisation instead of producing a systematic effect. In this review, we will discuss the new role of FGF23 in bone mineralisation and the pathophysiology of CKD-related bone disorders. PMID:25655009

  1. Neuropeptides as lung cancer growth factors.

    PubMed

    Moody, Terry W; Moreno, Paola; Jensen, Robert T

    2015-10-01

    This manuscript is written in honor of the Festschrift for Abba Kastin. I met Abba at a Society for Neuroscience meeting and learned that he was Editor-in-Chief of the Journal Peptides. I submitted manuscripts to the journal on "Neuropeptides as Growth Factors in Cancer" and subsequently was named to the Editorial Advisory Board. Over the past 30 years I have published dozens of manuscripts in Peptides and reviewed hundreds of submitted manuscripts. It was always rewarding to interact with Abba, a consummate professional. When I attended meetings in New Orleans I would sometimes go out to dinner with him at the restaurant "Commanders Palace". When I chaired the Summer Neuropeptide Conference we were honored to have him receive the Fleur Strand Award one year in Israel. I think that his biggest editorial contribution has been the "Handbook of Biologically Active Peptides." I served as a Section Editor on "Cancer/Anticancer Peptides" and again found that it was a pleasure working with him. This review focuses on the mechanisms by which bombesin-like peptides, neurotensin and vasoactive intestinal peptide regulate the growth of lung cancer. PMID:25836991

  2. Epidermal growth factor signaling in transformed cells

    PubMed Central

    Lindsey, Stephan; Langhans, Sigrid A.

    2016-01-01

    Members of the epidermal growth factor receptor (EGFR/ErbB) family play a critical role in normal cell growth and development. However, many ErbB family members, especially EGFR, are aberrantly expressed or deregulated in tumors and are thought to play crucial roles in cancer development and metastatic progression. In this chapter, we provide an overview of key mechanisms contributing to aberrant EGFR/ErbB signaling in transformed cells which results in many phenotypic changes associated with the earliest stages of tumor formation, including several hallmarks of epithelial-to-mesenchymal transition (EMT). These changes often occur through interaction with other major signaling pathways important to tumor progression resulting in a multitude of transcriptional changes that ultimately impact cell morphology, proliferation and adhesion, all of which are crucial for tumor progression. The resulting mesh of signaling networks will need to be taken into account as new regimens are designed for targeting EGFR for therapeutic intervention. As new insights into the molecular mechanisms of the cross-talk of EGFR signaling with other signaling pathways and their role in therapeutic resistance to anti-EGFR therapies are gained a continual reassessment of clinical therapeutic regimes and strategies will be required. Understanding the consequences and complexity of EGF signaling and how it relates to tumor progression is critical for the development of clinical compounds and establishing clinical protocols for the treatment of cancer. PMID:25619714

  3. The Fibroblast Growth Factor signaling pathway

    PubMed Central

    Ornitz, David M; Itoh, Nobuyuki

    2015-01-01

    The signaling component of the mammalian Fibroblast Growth Factor (FGF) family is comprised of eighteen secreted proteins that interact with four signaling tyrosine kinase FGF receptors (FGFRs). Interaction of FGF ligands with their signaling receptors is regulated by protein or proteoglycan cofactors and by extracellular binding proteins. Activated FGFRs phosphorylate specific tyrosine residues that mediate interaction with cytosolic adaptor proteins and the RAS-MAPK, PI3K-AKT, PLCγ, and STAT intracellular signaling pathways. Four structurally related intracellular non-signaling FGFs interact with and regulate the family of voltage gated sodium channels. Members of the FGF family function in the earliest stages of embryonic development and during organogenesis to maintain progenitor cells and mediate their growth, differentiation, survival, and patterning. FGFs also have roles in adult tissues where they mediate metabolic functions, tissue repair, and regeneration, often by reactivating developmental signaling pathways. Consistent with the presence of FGFs in almost all tissues and organs, aberrant activity of the pathway is associated with developmental defects that disrupt organogenesis, impair the response to injury, and result in metabolic disorders, and cancer. © 2015 Wiley Periodicals, Inc. PMID:25772309

  4. Identification and partial characterization of the fibroblast growth factor receptor of baby hamster kidney cells

    SciTech Connect

    Neufeld, G.; Gospodarowicz, D.

    1985-11-05

    The binding of biologically active, SVI-labeled basic fibroblast growth factor (FGF) to baby hamster kidney-derived cell line cells (BHK-21) was studied at 4 degrees C. Unlabeled FGF displaced cell surface bound SVI-FGF, but platelet-derived growth factor, epidermal growth factor, insulin, or transferrin did not. Binding was saturable both as a function of time and as a function of increasing SVI-FGF concentrations. Scatchard analysis of the binding data revealed the presence of about 1.2 X 10(5) binding sites/cell with an apparent KD of 270 pM. The number of the binding sites was down-regulated following preincubation of the cells with FGF. The density of binding sites/cell also decreased as an inverse function of cell density. When SVI-FGF binding was studied in a BHK-21 cell membrane preparation, it was found that the membranal binding site displayed a lower KD of 21 pM. SVI-FGF was covalently cross-linked to its cell surface receptor on intact BHK-21 cells using the homobifunctional agent disuccinimidyl suberate. Two macromolecular species with an apparent molecular weight of 145,000 and SV,000, respectively, were labeled under both reducing and nonreducing conditions. Unlabeled FGF competed with SVI-FGF for binding to both macromolecular species. The labeling of the macromolecules was also inhibited by heparin. No labeling was observed in the absence of the cross-linkers or when heat-inactivated SVI-FGF was used instead of radiolabeled, biologically active FGF.

  5. Design of Growth Factor Sequestering Biomaterials

    PubMed Central

    Belair, David G.; Le, Ngoc Nhi; Murphy, William L.

    2014-01-01

    Growth factors (GFs) are major regulatory proteins that can govern cell fate, migration, and organization. Numerous aspects of the cell milieu can modulate cell responses to GFs, and GF regulation is often achieved by the native extracellular matrix (ECM). For example, the ECM can sequester GFs and thereby control GF bioavailability. In addition, GFs can exert distinct effects depending on whether they are sequestered in solution, at two-dimensional interfaces, or within three-dimensional matrices. Understanding how the context of GF sequestering impacts cell function in the native ECM can instruct the design of soluble or insoluble GF sequestering moieties, which can then be used in a variety of bioengineering applications. This Feature Article provides an overview of the natural mechanisms of GF sequestering in the cell milieu, and reviews the recent bioengineering approaches that have sequestered GFs to modulate cell function. Results to date demonstrate that the cell response to GF sequestering depends on the affinity of the sequestering interaction, the spatial proximity of sequestering in relation to cells, the source of the GF (supplemented or endogenous), and the phase of the sequestering moiety (soluble or insoluble). We highlight the importance of context for the future design of biomaterials that can leverage endogenous molecules in the cell milieu and mitigate the need for supplemented factors. PMID:25182455

  6. Purification and characterization of a growth factor from rat platelets for mature parenchymal hepatocytes in primary cultures.

    PubMed Central

    Nakamura, T; Teramoto, H; Ichihara, A

    1986-01-01

    A growth factor (HGF) stimulating DNA synthesis of adult rat hepatocytes in primary culture was found in rat platelets. HGF was purified from rat platelets to homogeneity by a three-step procedure: stimulation of its release from platelets by thrombin, cation-exchanger fast protein liquid chromatography on a Mono S column, and heparin-Sepharose chromatography. HGF was clearly distinguishable from the platelet-derived growth factor (PDGF) by fast protein liquid chromatography. HGF was a heat- and acid-labile cationic protein that was inactivated by reduction with dithiothreitol. Its molecular mass was estimated to be 27 kDa by NaDodSO4/PAGE and its amino acid composition was very different from that of PDGF. The purified HGF stimulated DNA synthesis in adult rat hepatocytes at 2 ng/ml and was maximally effective at 20 ng/ml; its effect was additive or synergistic with those of insulin and EGF, depending on their combinations. HGF did not stimulate DNA synthesis of Swiss 3T3 cells, while PDGF did not stimulate that of hepatocytes. Thus, HGF showed clearly different cell specificity from PDGF in its growth-promoting activities. These findings indicate that HGF is a growth factor in platelets for mature hepatocytes. Images PMID:3529086

  7. Recurrent exposure to nicotine differentiates human bronchial epithelial cells via epidermal growth factor receptor activation

    SciTech Connect

    Martinez-Garcia, Eva; Irigoyen, Marta; Anso, Elena; Martinez-Irujo, Juan Jose; Rouzaut, Ana

    2008-05-01

    Cigarette smoking is the major preventable cause of lung cancer in developed countries. Nicotine (3-(1-methyl-2-pyrrolidinyl)-pyridine) is one of the major alkaloids present in tobacco. Besides its addictive properties, its effects have been described in panoply of cell types. In fact, recent studies have shown that nicotine behaves as a tumor promoter in transformed epithelial cells. This research focuses on the effects of acute repetitive nicotine exposure on normal human bronchial epithelial cells (NHBE cells). Here we show that treatment of NHBE cells with recurrent doses of nicotine up to 500 {mu}M triggered cell differentiation towards a neuronal-like phenotype: cells emitted filopodia and expressed neuronal markers such as neuronal cell adhesion molecule, neurofilament-M and the transcription factors neuronal N and Pax-3. We also demonstrate that nicotine treatment induced NF-kB translocation to the nucleus, phosphorylation of the epidermal growth factor receptor (EGFR), and accumulation of heparin binding-EGF in the extracellular medium. Moreover, addition of AG1478, an inhibitor of EGFR tyrosine phosphorylation, or cetuximab, a monoclonal antibody that precludes ligand binding to the same receptor, prevented cell differentiation by nicotine. Lastly, we show that differentiated cells increased their adhesion to the extracellular matrix and their protease activity. Given that several lung pathologies are strongly related to tobacco consumption, these results may help to better understand the damaging consequences of nicotine exposure.

  8. Heparin effect on DNA synthesis in a murine fibrosarcoma cell line: influence of anionic density

    SciTech Connect

    Piepkorn, M.W.; Daynes, R.A.

    1983-09-01

    The effects of heparin subfractions on DNA synthesis in a murine cutaneous fibrosarcoma cell line were examined. Porcine mucosal heparin was preparatively fractionated for anionic charge density by DEAE-Sephadex chromatography and for molecular weight by Sephadex G-100 filtration. The cell line was plated from confluent monolayer cultures and grown in medium and fetal bovine serum, with or without a heparin fraction at a final concentration of 10 micrograms/ml. At intervals thereafter, the cells were pulsed with (/sup 3/H)thymidine. A low-charge density heparin fraction stimulated (/sup 3/H)thymidine incorporation (cpm/mg protein and cpm/cell) during the first 3 days of growth compared to control values without added heparin, whereas a high-charge density heparin fraction had little of this effect (186 +/- 35% of control vs. 101 +/- 14%, respectively; P less than .05). The augmentation of DNA synthesis observed with the low-charge density fraction correlated with increased proportions of cells in S and G2 phases compared with those of the controls, as determined by flow cytofluorometry. Low- and high-molecular-weight heparin fractions did not significantly alter DNA synthesis. Heparin subfractions are thus heterogeneous with respect to their effect on cellular DNA synthesis in this tumor line.

  9. Unfractionated Heparin Promotes Osteoclast Formation in Vitro by Inhibiting Osteoprotegerin Activity.

    PubMed

    Li, Binghan; Lu, Dan; Chen, Yuqing; Zhao, Minghui; Zuo, Li

    2016-01-01

    Heparin has been proven to enhance bone resorption and induce bone loss. Since osteoclasts play a pivotal role in bone resorption, the effect of heparin on osteoclastogenesis needs to be clarified. Since osteocytes are the key modulator during osteoclastogenesis, we evaluated heparin's effect on osteoclastogenesis in vitro by co-culturing an osteocyte cell line (MLO-Y4) and pre-osteoclasts (RAW264.7). In this co-culture system, heparin enhanced osteoclastogenesis and osteoclastic bone resorption while having no influence on the production of RANKL (receptor activator of NFκB ligand), M-CSF (macrophage colony-stimulating factor), and OPG (osteoprotegerin), which are three main regulatory factors derived from osteocytes. According to previous studies, heparin could bind specifically to OPG and inhibit its activity, so we hypothesized that this might be a possible mechanism of heparin activity. To test this hypothesis, osteoclastogenesis was induced using recombinant RANKL or MLO-Y4 supernatant. We found that heparin has no effect on RANKL-induced osteoclastogenesis (contains no OPG). However, after incubation with OPG, the capacity of MLO-Y4 supernatant for supporting osteoclast formation was increased. This effect disappeared after OPG was neutralized and reappeared after OPG was replenished. These results strongly suggest that heparin promotes osteocyte-modulated osteoclastogenesis in vitro, at least partially, through inhibiting OPG activity. PMID:27110777

  10. Endorsement of Growth Factors in Experiential Training Groups

    ERIC Educational Resources Information Center

    Kiweewa, John; Gilbride, Dennis; Luke, Melissa; Seward, Derek

    2013-01-01

    The purpose of this study was to identify student growth factors during a semester long Master's level group counseling class. Results indicated that 12 growth factors accounted for 86% of the total number of critical incidents that participants reported as influencing their personal growth and awareness during the group experience. Two other…

  11. Heparin-decorated, hyaluronic acid-based hydrogel particles for the controlled release of bone morphogenetic protein 2

    PubMed Central

    Xu, Xian; Jha, Amit K.; Duncan, Randall L.; Jia, Xinqiao

    2011-01-01

    We are interested in developing hydrophilic particulate systems that are capable of sequestering growth factors, regulating their release and potentiating their biological functions. Towards this end, heparin (HP)-decorated, hyaluronic acid (HA)-based, hydrogel particles (HGPs) were synthesized using an inverse emulsion polymerization technique employing divinyl sulfone as the crosslinker. By varying the feed composition of the aqueous phase, the amount of heparin integrated in the particles can be systematically tuned. The resulting microscopic particles are spherical in shape and contain nanosized pores suitable for growth factor encapsulation. The covalently immobilized heparin retained its ability to bind bone morphogenetic protein 2 (BMP-2) specifically, and its release kinetics can be adjusted by tuning the particle composition. Compared to the pure HA particles, the hybrid HA/HP HGPs show a higher BMP-2 loading capacity. While BMP-2 was released from HA HGPs with a significant initial burst, a near zero-order release kinetics was observed from HA/HP hybrid particles with an optimized heparin content of 0.55 μg per milligram HGPs. The ability of HA/HP hybrid particles to present BMP-2 in a controlled manner, combined with the innate bioactivity of HA, induced robust and consistent chondrogenic differentiation of murine mesenchymal stem cells, as evidenced by the up-regulation of mRNA levels of chondrogenic markers and the production of cartilage-specific extracellular matrix components. The simplicity of the particle synthesis, combined with the defined biological activities of the constituent building blocks, renders the HP-decorated, HA-based hydrogel particle system an attractive candidate for the sustained release of BMP-2, possibly for cartilage repair and regeneration. PMID:21550426

  12. Gene Expression of Growth Factors and Growth Factor Receptors for Potential Targeted Therapy of Canine Hepatocellular Carcinoma

    PubMed Central

    IIDA, Gentoku; ASANO, Kazushi; SEKI, Mamiko; SAKAI, Manabu; KUTARA, Kenji; ISHIGAKI, Kumiko; KAGAWA, Yumiko; YOSHIDA, Orie; TESHIMA, Kenji; EDAMURA, Kazuya; WATARI, Toshihiro

    2013-01-01

    ABSTRACT The purpose of this study was to evaluate the gene expression of growth factors and growth factor receptors of primary hepatic masses, including hepatocellular carcinoma (HCC) and nodular hyperplasia (NH), in dogs. Quantitative real-time reverse transcriptase-polymerase chain reaction was performed to measure the expression of 18 genes in 18 HCCs, 10 NHs, 11 surrounding non-cancerous liver tissues and 4 healthy control liver tissues. Platelet-derived growth factor-B (PDGF-B), transforming growth factor-α, epidermal growth factor receptor, epidermal growth factor and hepatocyte growth factor were found to be differentially expressed in HCC compared with NH and the surrounding non-cancerous and healthy control liver tissues. PDGF-B is suggested to have the potential to become a valuable ancillary target for the treatment of canine HCC. PMID:24189579

  13. Growth factor involvement in tension-induced skeletal muscle growth

    NASA Technical Reports Server (NTRS)

    Vandenburgh, Herman W.

    1987-01-01

    New muscle tissue culture techniques were developed to grow embryonic skeletal myofibers which are able to differentiate into more adultlike myofibers. Studies on mechanical simulation of cultured muscle cell growth will now be more directly applicable to mechanically-induced growth in adult muscle, and lead to better models for understanding muscle tissue atrophy caused by disuse in the microgravity of space.

  14. The neuronal cell-surface molecule mitogenic for Schwann cells is a heparin-binding protein.

    PubMed Central

    Ratner, N; Hong, D M; Lieberman, M A; Bunge, R P; Glaser, L

    1988-01-01

    The cell surface of embryonic peripheral neurons provides a mitogenic stimulus for Schwann cells. We report (i) the solubilization of this mitogenic activity from rat dorsal root ganglion neurons grown in tissue culture and (ii) the solubilization and partial purification of mitogenic activity from neonatal rat brains. Extracted mitogenic activity is peripheral rather than intrinsic to the membrane, stable after extraction, and active as a mitogen in the absence of serum (the most stringent criterion defining the neuronal mitogen). We have previously provided evidence suggesting that a neuronal cell-surface heparan sulfate proteoglycan is required for expression of the neurons' mitogenic activity. We now show that mitogenic activity can be extracted from the membrane dissociated from proteoglycan as assayed by its ability to bind to immobilized heparin. After dissociation, low concentrations of heparin (1 micrograms/ml) inhibit the ability of the mitogen to stimulate Schwann cell division. Basic fibroblast growth factor (FGF) is weakly mitogenic for Schwann cells, but it is not present in mitogenic brain extracts (based on immunoblotting). Immunodepletion experiments with specific antibodies to FGF indicate that the mitogenic activity extracted from neurons is not a form of this heparin-binding mitogen. Acidic FGF is not mitogenic for Schwann cells and is not present in mitogenic brain extracts. We suggest that these and previous data indicate the neurite mitogen is a proteoglycan-growth factor complex that limits mitogenic activity to the axonal surface, protects mitogen against inactivation by other proteoglycans, and provides for effective presentation of mitogen to the Schwann cell. PMID:3413130

  15. Isolated placental vessel response to vascular endothelial growth factor and placenta growth factor in normal and growth-restricted pregnancy.

    PubMed

    Szukiewicz, Dariusz; Szewczyk, Grzegorz; Watroba, Mateusz; Kurowska, Ewa; Maslinski, Slawomir

    2005-01-01

    Vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF) cause vasodilation. We examined the vasomotor response of isolated placental vessels to VEGF and PlGF in normal (group I) and intrauterine growth retardation (IUGR)-complicated pregnancy (group II). Rings of vessels were prepared in vitro and mounted on the vessel myograph plunged in tissue bath. The magnitude of dilation to increased doses of VEGF and PlGF has been studied. VEGF is a more potent vasodilator than PlGF. Both, VEGF- and PlGF-induced vasorelaxation was diminished in the IUGR (group II) nearly by half, compared to control (group I). Relative placental nitric oxide deficiency, or decreased sensitivity to VEGF and PlGF may contribute to the development of high impedance fetoplacental circulation. PMID:15591804

  16. The Role of Vascular Endothelial Growth Factors and Fibroblast Growth Factors in Angiogenesis during Otitis Media

    PubMed Central

    Husseman, Jacob; Palacios, Sean D.; Rivkin, Alexander Z.; Oehl, Heinz; Ryan, Allen F.

    2012-01-01

    The middle ear response to otitis media includes transformation and hyperplasia of the mucosal epithelium and subepithelial connective tissue. Significant neovascularization is also noted, which occurs both to support the hypertrophied mucosa and to mediate the increased trafficking of leukocytes. We investigated the role of two known potent angiogenic growth factor families, the fibroblast growth factors (FGFs) and vascular endothelial growth factors (VEGFs), in middle ear mucosal angiogenesis. DNA microarrays were used to evaluate the expression of FGFs and VEGFs, as well as their receptors and unique signaling proteins, in the middle ears of mice undergoing a complete course of acute bacterial otitis media. In addition, a member of each family was introduced to the middle ear submucosal compartment of the normal middle ears of guinea pigs, by a continuous-release osmotic minipump system over 1 week. During the course of bacterial otitis media, a significant regulation of a number of genes important for angiogenesis was identified. Histologic evaluation of middle ear mucosa following micropump infusion of both FGF1 and VEGF-A showed significant angiogenesis at the site of infusion in comparison to control saline infusion. These results support a role for FGFs and VEGFs in the neovascularization of the middle ear mucosa during otitis media, and offer a potential avenue for therapeutic intervention. PMID:22104377

  17. Direct binding of hepatocyte growth factor and vascular endothelial growth factor to CD44v6

    PubMed Central

    Volz, Yvonne; Koschut, David; Matzke-Ogi, Alexandra; Dietz, Marina S.; Karathanasis, Christos; Richert, Ludovic; Wagner, Moritz G.; Mély, Yves; Heilemann, Mike; Niemann, Hartmut H.; Orian-Rousseau, Véronique

    2015-01-01

    CD44v6, a member of the CD44 family of transmembrane glycoproteins is a co-receptor for two receptor tyrosine kinases (RTKs), Met and VEGFR-2 (vascular endothelial growth factor receptor 2). CD44v6 is not only required for the activation of these RTKs but also for signalling. In order to understand the role of CD44v6 in Met and VEGFR-2 activation and signalling we tested whether CD44v6 binds to their ligands, HGF (hepatocyte growth factor) and VEGF (vascular endothelial growth factor), respectively. FACS analysis and cellular ELISA showed binding of HGF and VEGF only to cells expressing CD44v6. Direct binding of CD44v6 to HGF and VEGF was demonstrated in pull-down assays and the binding affinities were determined using MicroScale Thermophoresis, fluorescence correlation spectroscopy and fluorescence anisotropy. The binding affinity of CD44v6 to HGF is in the micromolar range in contrast with the high-affinity binding measured in the case of VEGF and CD44v6, which is in the nanomolar range. These data reveal a heparan sulfate-independent direct binding of CD44v6 to the ligands of Met and VEGFR-2 and suggest different roles of CD44v6 for these RTKs. PMID:26181364

  18. Connective tissue growth factor in tumor pathogenesis

    PubMed Central

    2012-01-01

    Key roles for connective tissue growth factor (CTGF/CCN2) are demonstrated in the wound repair process where it promotes myofibroblast differentiation and angiogenesis. Similar mechanisms are active in tumor-reactive stroma where CTGF is expressed. Other potential roles include prevention of hypoxia-induced apoptosis and promoting epithelial-mesenchymal transistion (EMT). CTGF expression in tumors has been associated to both tumor suppression and progression. For example, CTGF expression in acute lymphoblastic leukemia, breast, pancreas and gastric cancer correlates to worse prognosis whereas the opposite is true for colorectal, lung and ovarian cancer. This discrepancy is not yet understood. High expression of CTGF is a hallmark of ileal carcinoids, which are well-differentiated endocrine carcinomas with serotonin production originating from the small intestine and proximal colon. These tumors maintain a high grade of differentiation and low proliferation. Despite this, they are malignant and most patients have metastatic disease at diagnosis. These tumors demonstrate several phenotypes potentially related to CTGF function namely: cell migration, absent tumor cell apoptosis, as well as, reactive and well vascularised myofibroblast rich stroma and fibrosis development locally and in distal organs. The presence of CTGF in other endocrine tumors indicates a role in the progression of well-differentiated tumors. PMID:23259759

  19. Vascular Endothelial Growth Factor in Eye Disease

    PubMed Central

    Penn, J.S.; Madan, A.; Caldwell, R.B.; Bartoli, M.; Caldwell, R.W.; Hartnett, M.E.

    2012-01-01

    Collectively, angiogenic ocular conditions represent the leading cause of irreversible vision loss in developed countries. In the U.S., for example, retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration are the principal causes of blindness in the infant, working age and elderly populations, respectively. Evidence suggests that vascular endothelial growth factor (VEGF), a 40 kDa dimeric glycoprotein, promotes angiogenesis in each of these conditions, making it a highly significant therapeutic target. However, VEGF is pleiotropic, affecting a broad spectrum of endothelial, neuronal and glial behaviors, and confounding the validity of anti-VEGF strategies, particularly under chronic disease conditions. In fact, among other functions VEGF can influence cell proliferation, cell migration, proteolysis, cell survival and vessel permeability in a wide variety of biological contexts. This article will describe the roles played by VEGF in the pathogenesis of retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. The potential disadvantages of inhibiting VEGF will be discussed, as will the rationales for targeting other VEGF-related modulators of angiogenesis. PMID:18653375

  20. [Epidermal growth factor, innovation and safety].

    PubMed

    Esquirol Caussa, Jordi; Herrero Vila, Elisabeth

    2015-10-01

    Bioidentical recombinant human epidermal growth factor (rhEGF) is available in concentrations and purity suitable for therapeutic use in long time stable formulations. Beneficial effects in several skin pathologies and lesions have been reported (traumatic and surgical wound healing, laser induced wounds, abnormal scars, keloids, radiation or chemotherapy induced dermatitis, post inflammatory hyperpigmentation or for skin aging damage repairing) and also may be considered for the treatment of several oropharingeal and high gastroesophageal tract mucosa diseases (mouth sores, pharyngeal fistulas, ulcers), and several corneal or conjunctive mucosa lesions. rhEGF has not shown any important side or collateral effects in humans or in laboratory experimentation animals, showing optimal tolerability and safety with continuous use for months. Compounding gives advantages of versatility, individualization, personalization, molecular stability, safety and effectiveness in ideal conditions, showing good tissue penetration, both on intact skin and skin lesions that expose the lower planes to the surface. rhEGF compounds can be considered for prevention or as a treatment of diverse skin and mucosa diseases and conditions through compounding preparations. PMID:25433777

  1. Interactions of signaling proteins, growth factors and other proteins with heparan sulfate: mechanisms and mysteries.

    PubMed

    Billings, Paul C; Pacifici, Maurizio

    2015-01-01

    Heparan sulfate (HS) is a component of cell surface and matrix-associated proteoglycans (HSPGs) that, collectively, play crucial roles in many physiologic processes including cell differentiation, organ morphogenesis and cancer. A key function of HS is to bind and interact with signaling proteins, growth factors, plasma proteins, immune-modulators and other factors. In doing so, the HS chains and HSPGs are able to regulate protein distribution, bio-availability and action on target cells and can also serve as cell surface co-receptors, facilitating ligand-receptor interactions. These proteins contain an HS/heparin-binding domain (HBD) that mediates their association and contacts with HS. HBDs are highly diverse in sequence and predicted structure, contain clusters of basic amino acids (Lys and Arg) and possess an overall net positive charge, most often within a consensus Cardin-Weintraub (CW) motif. Interestingly, other domains and residues are now known to influence protein-HS interactions, as well as interactions with other glycosaminoglycans, such as chondroitin sulfate. In this review, we provide a description and analysis of HBDs in proteins including amphiregulin, fibroblast growth factor family members, heparanase, sclerostin and hedgehog protein family members. We discuss HBD structural and functional features and important roles carried out by other protein domains, and also provide novel conformational insights into the diversity of CW motifs present in Sonic, Indian and Desert hedgehogs. Finally, we review progress in understanding the pathogenesis of a rare pediatric skeletal disorder, Hereditary Multiple Exostoses (HME), characterized by HS deficiency and cartilage tumor formation. Advances in understanding protein-HS interactions will have broad implications for basic biology and translational medicine as well as for the development of HS-based therapeutics. PMID:26076122

  2. Fibroblast Growth Factors and Vascular Endothelial Growth Factor Promote Cardiac Reprogramming under Defined Conditions

    PubMed Central

    Yamakawa, Hiroyuki; Muraoka, Naoto; Miyamoto, Kazutaka; Sadahiro, Taketaro; Isomi, Mari; Haginiwa, Sho; Kojima, Hidenori; Umei, Tomohiko; Akiyama, Mizuha; Kuishi, Yuki; Kurokawa, Junko; Furukawa, Tetsushi; Fukuda, Keiichi; Ieda, Masaki

    2015-01-01

    Summary Fibroblasts can be directly reprogrammed into cardiomyocyte-like cells (iCMs) by overexpression of cardiac transcription factors, including Gata4, Mef2c, and Tbx5; however, this process is inefficient under serum-based culture conditions, in which conversion of partially reprogrammed cells into fully reprogrammed functional iCMs has been a major hurdle. Here, we report that a combination of fibroblast growth factor (FGF) 2, FGF10, and vascular endothelial growth factor (VEGF), termed FFV, promoted cardiac reprogramming under defined serum-free conditions, increasing spontaneously beating iCMs by 100-fold compared with those under conventional serum-based conditions. Mechanistically, FFV activated multiple cardiac transcriptional regulators and converted partially reprogrammed cells into functional iCMs through the p38 mitogen-activated protein kinase and phosphoinositol 3-kinase/AKT pathways. Moreover, FFV enabled cardiac reprogramming with only Mef2c and Tbx5 through the induction of cardiac reprogramming factors, including Gata4. Thus, defined culture conditions promoted the quality of cardiac reprogramming, and this finding provides new insight into the mechanism of cardiac reprogramming. PMID:26626177

  3. Heparin induces the expression of specific matrix proteins by human intestinal smooth muscle cells

    SciTech Connect

    Cochran, D.L.; Perr, H.; Graham, M.F.; Diegelmann, R.F.

    1986-03-01

    Human intestinal smooth muscle (HISM) cells have recently been identified as the major cell type responsible for stricture formation in Crohn's disease. Heparin, a sulfated glycosaminoglycan, has been shown to be a key modulator of vascular smooth muscle cell (VSMC) growth both in vivo and in vitro and to affect the phenotypic expression of proteins made by VSMC. Heparin has also been shown to effect the growth of HISM cells and in this report the authors demonstrate that heparin also has very specific effects on proteins released by HISM cells in vitro. Examination of the proteins in the culture medium of heparin-treated HISM cells observed at 3 time points following sparse plating and proliferation revealed an increase in /sup 35/S-methionine-labeled 200, 37, and 35 kd proteins. A transient effect on a 48 kd protein was observed in substrate-attached material left on the culture dish after the cells were removed with EGTA. No effects on intracellular labeled proteins could be demonstrated. The protein phenotype of HISM cells exposed to heparin appears very similar to that observed in VSMC. The release of specific proteins following exposure to heparin does not appear to be species specific. This response to heparin may reflect a significant influence of this glycosaminoglycan on the phenotypic expression of these cells.

  4. Fibroblast Growth Factor Signaling in Metabolic Regulation

    PubMed Central

    Nies, Vera J. M.; Sancar, Gencer; Liu, Weilin; van Zutphen, Tim; Struik, Dicky; Yu, Ruth T.; Atkins, Annette R.; Evans, Ronald M.; Jonker, Johan W.; Downes, Michael Robert

    2016-01-01

    The prevalence of obesity is a growing health problem. Obesity is strongly associated with several comorbidities, such as non-alcoholic fatty liver disease, certain cancers, insulin resistance, and type 2 diabetes, which all reduce life expectancy and life quality. Several drugs have been put forward in order to treat these diseases, but many of them have detrimental side effects. The unexpected role of the family of fibroblast growth factors in the regulation of energy metabolism provides new approaches to the treatment of metabolic diseases and offers a valuable tool to gain more insight into metabolic regulation. The known beneficial effects of FGF19 and FGF21 on metabolism, together with recently discovered similar effects of FGF1 suggest that FGFs and their derivatives carry great potential as novel therapeutics to treat metabolic conditions. To facilitate the development of new therapies with improved targeting and minimal side effects, a better understanding of the molecular mechanism of action of FGFs is needed. In this review, we will discuss what is currently known about the physiological roles of FGF signaling in tissues important for metabolic homeostasis. In addition, we will discuss current concepts regarding their pharmacological properties and effector tissues in the context of metabolic disease. Also, the recent progress in the development of FGF variants will be reviewed. Our goal is to provide a comprehensive overview of the current concepts and consensuses regarding FGF signaling in metabolic health and disease and to provide starting points for the development of FGF-based therapies against metabolic conditions. PMID:26834701

  5. Sequential delivery of angiogenic growth factors improves revascularization and heart function after myocardial infarction

    PubMed Central

    Awada, Hassan K.; Johnson, Noah R.; Wang, Yadong

    2015-01-01

    Treatment of ischemia through therapeutic angiogenesis faces significant challenges. Growth factor (GF)-based therapies can be more effective when concerns such as GF spatiotemporal presentation, bioactivity, bioavailability, and localization are addressed. During angiogenesis, vascular endothelial GF (VEGF) is required early to initiate neovessel formation while platelet-derived GF (PDGF-BB) is needed later to stabilize the neovessels. The spatiotemporal delivery of multiple bioactive GFs involved in angiogenesis, in a close mimic to physiological cues, holds great potential to treat ischemic diseases. To achieve sequential release of VEGF and PDGF, we embed VEGF in fibrin gel and PDGF in a heparin-based coacervate that is distributed in the same fibrin gel. In vitro, we show the benefits of this controlled delivery approach on cell proliferation, chemotaxis, and capillary formation. A rat myocardial infarction (MI) model demonstrated the effectiveness of this delivery system in improving cardiac function, ventricular wall thickness, angiogenesis, cardiac muscle survival, and reducing fibrosis and inflammation in the infarct zone compared to saline, empty vehicle, and free GFs. Collectively, our results show that this delivery approach mitigated the injury caused by MI and may serve as a new therapy to treat ischemic hearts pending further examination. PMID:25836592

  6. Antivascular Endothelial Growth Factor Agents for Neovascular Age-Related Macular Degeneration

    PubMed Central

    Zampros, Ilias; Praidou, Anna; Brazitikos, Periklis; Ekonomidis, Panagiotis; Androudi, Sofia

    2012-01-01

    Age-related macular degeneration (AMD) is the leading cause of severe visual loss and blindness over the age of 50 in developed countries. Vascular endothelial growth factor (VEGF) is considered as a critical molecule in the pathogenesis of choroidal neovascularization (CNV), which characterizes the neovascular AMD. Anti-VEGF agents are considered the most promising way of effectively inhibition of the neovascular AMD process. VEGF is a heparin-binding glycoprotein with potent angiogenic, mitogenic and vascular permeability-enhancing activities specific for endothelial cells. Two anti-VEGF agents have been approved by the US Food and Drug Administration (FDA) for the treatment of neovascular AMD. Pegaptanib sodium, which is an aptamer and ranibizumab, which is a monoclonal antibody fragment. Another humanized monoclonal antibody is currently off-label used, bevacizumab. This paper aims to discuss in details the effectiveness, the efficacy and safety of these three anti-VEGF agents. New anti-VEGF compounds which are recently investigated for their clinical usage (VEGF-trap, small interfering RNA) are also discussed for their promising outcomes. PMID:22174998

  7. Nucleolin regulates phosphorylation and nuclear export of fibroblast growth factor 1 (FGF1).

    PubMed

    Sletten, Torunn; Kostas, Michal; Bober, Joanna; Sorensen, Vigdis; Yadollahi, Mandana; Olsnes, Sjur; Tomala, Justyna; Otlewski, Jacek; Zakrzewska, Malgorzata; Wiedlocha, Antoni

    2014-01-01

    Extracellular fibroblast growth factor 1 (FGF1) acts through cell surface tyrosine kinase receptors, but FGF1 can also act directly in the cell nucleus, as a result of nuclear import of endogenously produced, non-secreted FGF1 or by transport of extracellular FGF1 via endosomes and cytosol into the nucleus. In the nucleus, FGF1 can be phosphorylated by protein kinase C δ (PKCδ), and this event induces nuclear export of FGF1. To identify intracellular targets of FGF1 we performed affinity pull-down assays and identified nucleolin, a nuclear multifunctional protein, as an interaction partner of FGF1. We confirmed a direct nucleolin-FGF1 interaction by surface plasmon resonance and identified residues of FGF1 involved in the binding to be located within the heparin binding site. To assess the biological role of the nucleolin-FGF1 interaction, we studied the intracellular trafficking of FGF1. In nucleolin depleted cells, exogenous FGF1 was endocytosed and translocated to the cytosol and nucleus, but FGF1 was not phosphorylated by PKCδ or exported from the nucleus. Using FGF1 mutants with reduced binding to nucleolin and a FGF1-phosphomimetic mutant, we showed that the nucleolin-FGF1 interaction is critical for the intranuclear phosphorylation of FGF1 by PKCδ and thereby the regulation of nuclear export of FGF1. PMID:24595027

  8. Human mast cell basic fibroblast growth factor in pulmonary fibrotic disorders.

    PubMed Central

    Inoue, Y.; King, T. E.; Tinkle, S. S.; Dockstader, K.; Newman, L. S.

    1996-01-01

    Mast cells (MCs) are abundant in fibrotic tissue, although their role in fibrogenesis remains obscure. Recent studies suggest MCs may produce basic fibroblast growth factor (bFGF). To evaluate the hypothesis that MC bFGF contributes to the fibrotic response in human interstitial lung disease, we studied lung tissue, bronchoalveolar lavage fluid and serum in 1) idiopathic pulmonary fibrosis, 2) chronic beryllium disease and sarcoidosis, 3) control subjects with no disease or who were beryllium sensitized with normal lung histology. Diseased subjects underwent clinical assessments to stage disease severity. We determined that most bFGF+ cells in lung interstitium are MCs and are most abundant in idiopathic pulmonary fibrosis. Distribution of bFGF+ MCs matched that of extracellular matrix deposition and correlated with the extent of fibrosis morphometrically. Only one bFGF isoform (17.8 kd) was found in idiopathic pulmonary fibrosis and chronic beryllium disease lung tissues and interacted with heparin-like molecules in the lung. Using a human MC line, we verified that MCs express bFGF mRNA and protein that localizes to cytoplasmic granules. Clinically, bFGF concentrations in bronchoalveolar lavage fluid and serum were highest in disease states and correlated with bronchoalveolar lavage cellularity and severity of gas exchange abnormalities, supporting a role for MC bFGF in the pulmonary fibrotic response and its clinical consequence. Images Figure 1 Figure 2 Figure 7 Figure 10 Figure 11 Figure 12 PMID:8952537

  9. Novel Drosophila receptor that binds multiple growth factors

    SciTech Connect

    Rosner, M.R.; Thompson, K.L.; Garcia, V.; Decker, S.J.

    1986-05-01

    The authors have recently reported the identification of a novel growth factor receptor from Drosophila cell cultures that has dual binding specificity for both insulin and epidermal growth factor (EGF). This 100 kDa protein is also antigenically related to the cytoplasmic region of the mammalian EGF receptor-tyrosine kinase. They now report that this protein binds to mammalian nerve growth factor and human transforming growth factor alpha as well as insulin and EGF with apparent dissociation constants ranging from 10/sup -6/ to 10/sup -8/ M. The 100 kDa protein can be affinity-labeled with these /sup 125/I-labeled growth factors after immunoprecipitation with anti-EGF receptor antiserum. These four growth factors appear to share a common binding site, as evidenced by their ability to block affinity labelling by /sup 125/I-insulin. No significant binding to the 100 kDa protein was observed with platelet-derived growth factor, transforming growth factor beta, or glucagon. The 100 kDa Drosophila protein has a unique ligand-binding spectrum with no direct counterpart in mammalian cells and may represent an evolutionary precursor of the mammalian receptors for these growth factors.

  10. Growth factor array fabrication using a color ink jet printer.

    PubMed

    Watanabe, Kohei; Miyazaki, Takeshi; Matsuda, Ryoichi

    2003-04-01

    We have developed a novel method for growth factor analysis using a commercial color ink jet printer to fabricate substrata patterned with growth factors. We prepared substrata with insulin printed in a simple pattern or containing multiple areas of varying quantities of printed insulin. When we cultured the mouse myoblast cell line, C2C12, on the insulin-patterned substrata, the cells were grown in the same pattern with the insulin-printed pattern. Cell culture with the latter substrata demonstrated that quantity control of insulin deposition by a color ink jet printer is possible. For further applications, we developed substrata with insulin-like growth factor-I (IGF-I) and basic fibroblast growth factor (bFGF) spotted in 16 different areas in varying combinations and concentrations (growth factor array). With this growth factor array, C2C12 cells were cultured, and the onset of muscle cell differentiation was monitored for the expression of the myogenic regulator myogenin. The ratio of cells expressing myogenin varied with the doses of IGF-I and bFGF in the sections, demonstrating a feasibility of growth factor array fabrication by a color ink jet printer. Since a printer manipulates several colors, this method can be easily applied to multivariate analyses of growth factors and attachment factors affecting cell growth and differentiation. This method may provide a powerful tool for cell biology and tissue engineering, especially for stem cell research in investigating unknown conditions for differentiation. PMID:12719645