Blood pressure modulation following activation of mast cells by cationic cell penetrating peptides.

Laboratory of Biotechnology and Radiobiology, Sharett Institute of Oncology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
Peptides (Impact Factor: 2.61). 12/2011; 32(12):2444-51. DOI: 10.1016/j.peptides.2011.09.017
Source: PubMed

ABSTRACT Short cell penetrating peptides (CPP) are widely used in vitro to transduce agents into cells. But their systemic effect has not been yet studied in detail. We studied the systemic effect of the cell penetrating peptides, penetratin, transportan and pro-rich, on rat hemodynamic functions. Intra-arterial monitoring of blood pressure showed that injection of the positively charged penetratin and transportan in a wide range of concentrations (2.5-320 μg/kg) caused highly significant transient decrease in the systolic and diastolic blood pressure in a dose dependent manner (p<0.01). Pretreatment with histamine receptors blockers or with cromolyn, a mast cell stabilizing agent, significantly attenuated this effect. Furthermore, in vitro incubation of these both peptides with mast cells line, LAD2, caused a massive mast cell degranulation. In vitro studies showed that these CPP in a wide range of concentrations were not cytotoxic without any effect on the survival of LAD2 mast cell line. In contrast, the less positively charged and proline-rich CPP, pro-rich, had no systemic effects with no effect on mast cell degranulation. Our results indicate that intravenously administrated positively charged CPP may have deleterious consequences due to their induced BP drop, mediated by mast cell activation. Therefore, the major effect of mast cell activation on BP should be considered in developing possible future drug therapies based on the injection of membrane-permeable and positively charged CPP. Nevertheless, lower levels of such CPP may be considered as a treatment of systemic high BP through moderate systemic mast cell activation.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We tested the ability of purified, ultraviolet C virally inactivated components of human fibrin sealant (FS) to modulate the chemotaxis, adherence, and proliferation of cultured cells. A fibrin clot formed on a near-confluent layer of human fibroblasts (HFs) recruited cells from the surrounding area. Thrombin (Thr) enhanced HF proliferation by a factor of 1.5 to 1.8, whereas fibrinogen (Fib) exerted only a minimal proliferative effect. We developed a new cell haptotactic/attachment assay by using Thr and Fib covalently bound to Sepharose beads (SBs). The kinetics of cell binding were approximately equivalent for beads coated with either protein. Uncoated SBs or fibrinogen-bound SBs (Fib-SB) pretreated with plasmin did not attract HFs. AlphaThr-SB induced a positive migratory response that was not affected by blocking its proteolytic site, whereas gammaThr-SB elicited no response. X irradiation of HFs at a dose of 6 Gy showed that the migratory response of HF is independent of proliferation, as confirmed by a bromodeoxyuridine uptake assay. Several types of cultured cells (murine fibroblasts, smooth muscle cells, aortic endothelial cells, and murine mammary carcinoma cells) also attached to Fib-SB. By contrast, human keratinocytes, human ovarian carcinoma cells, murine macrophage-like cells, leukemic cells, and murine mast cells did not attach. Our results provide some mechanistic insights into the haptotactic and proliferative effects of Fib and Thr on different cells.
    Journal of Laboratory and Clinical Medicine 04/1998; 131(3):269-80. · 2.62 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Fibrinogen seems to contribute significantly to cell binding and recruitment into wounds besides its major role in clot formation. We describe 19- to 21-mer cell-binding (haptotactic) peptides from the C-termini of fibrinogen beta-chain (Cbeta), the extended alphaE chain, and near the C-terminal of the gamma-chain. When these peptides were covalently bound to a biologically inert matrix such as Sepharose beads (SB), they elicited beads attachment to cells, mostly of mesenchymal origin (including fibroblasts, endothelial cells, and smooth muscle cells) as well as some transformed cell lines. Based on such haptotactic activity, these peptides were termed "haptides." By contrast, peptides homologous to fibrinogen C-termini alpha- and gamma-chains elicited no such activity. The haptide Cbeta could not block the interaction of fibroblasts with antibodies directed against integrins beta(1), alpha(v), alpha(v)beta(1), alpha(v)beta(3), and alphaIIbeta(3). Moreover, GRGDS peptide could not inhibit enhanced cell binding to SB-Cbeta, as expected from an integrin-mediated process. In soluble form the haptides were accumulated in cells with nonsaturable kinetics without any toxic or proproliferative effects in concentrations up to 80 microM. These findings suggest that the conserved haptidic sequences within fibrin(ogen) can be associated with the adhesion and migration of cells into fibrin clots and may have a significant role in normal wound healing and in various pathological conditions.
    Experimental Cell Research 08/2003; 287(1):116-29. · 3.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Fibrinogen molecules are comprised of two sets of disulfide-bridged Aalpha-, Bbeta-, and gamma-chains. Each molecule contains two outer D domains connected to a central E domain by a coiled-coil segment. Fibrin is formed after thrombin cleavage of fibrinopeptide A (FPA) from fibrinogen Aalpha-chains, thus initiating fibrin polymerization. Double-stranded fibrils form through end-to-middle domain (D:E) associations, and concomitant lateral fibril associations and branching create a clot network. Fibrin assembly facilitates intermolecular antiparallel C-terminal alignment of gamma-chain pairs, which are then covalently 'cross-linked' by factor XIII ('plasma protransglutaminase') or XIIIa to form 'gamma-dimers'. In addition to its primary role of providing scaffolding for the intravascular thrombus and also accounting for important clot viscoelastic properties, fibrin(ogen) participates in other biologic functions involving unique binding sites, some of which become exposed as a consequence of fibrin formation. This review provides details about fibrinogen and fibrin structure, and correlates this information with biological functions that include: (i) suppression of plasma factor XIII-mediated cross-linking activity in blood by binding the factor XIII A2B2 complex. (ii) Non-substrate thrombin binding to fibrin, termed antithrombin I (AT-I), which down-regulates thrombin generation in clotting blood. (iii) Tissue-type plasminogen activator (tPA)-stimulated plasminogen activation by fibrin that results from formation of a ternary tPA-plasminogen-fibrin complex. Binding of inhibitors such as alpha2-antiplasmin, plasminogen activator inhibitor-2, lipoprotein(a), or histidine-rich glycoprotein, impairs plasminogen activation. (iv) Enhanced interactions with the extracellular matrix by binding of fibronectin to fibrin(ogen). (v) Molecular and cellular interactions of fibrin beta15-42. This sequence binds to heparin and mediates platelet and endothelial cell spreading, fibroblast proliferation, and capillary tube formation. Interactions between beta15-42 and vascular endothelial (VE)-cadherin, an endothelial cell receptor, also promote capillary tube formation and angiogenesis. These activities are enhanced by binding of growth factors like fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF), and cytokines like interleukin (IL)-1. (vi) Fibrinogen binding to the platelet alpha(IIb)beta3 receptor, which is important for incorporating platelets into a developing thrombus. (vii) Leukocyte binding to fibrin(ogen) via integrin alpha(M)beta2 (Mac-1), which is a high affinity receptor on stimulated monocytes and neutrophils.
    Journal of Thrombosis and Haemostasis 09/2005; 3(8):1894-904. · 5.55 Impact Factor


Available from
Jul 21, 2014