| 1. |
- Dixelius, Johan, et al.
(författare)
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Minimal active domain and mechanism of action of the angiogenesis inhibitor histidine-rich glycoprotein
- 2006
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 66:4, s. 2089-97
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Tidskriftsartikel (refereegranskat)abstract
- Histidine-rich glycoprotein (HRGP) is an abundant heparin-binding plasma protein that efficiently arrests growth and vascularization of mouse tumor models. We have shown that the antiangiogenic effect of HRGP is dependent on its histidine/proline-rich domain, which needs to be released from the mother protein to exert its effects. Here we identify a 35-amino-acid peptide, HRGP330, derived from the histidine/proline-rich domain as endowed with antiangiogenic properties in vitro and in vivo. The mechanism of action of HRGP330 involves subversion of focal adhesion function by disruption of integrin-linked kinase (ILK) and focal adhesion kinase (FAK) functions, inhibition of vascular endothelial growth factor (VEGF)-induced tyrosine phosphorylation of the FAK substrate alpha-actinin, and, as a consequence, an arrest in endothelial cell motility. The disturbed focal adhesion function is reflected in the ability of HRGP as well as of HRGP330 to prevent endothelial cell adhesion to vitronectin in a manner involving alpha(v)beta3 integrin. In conclusion, HRGP330, which we define as the minimal antiangiogenic domain of HRGP, exerts its effects through signal transduction targeting focal adhesions, thereby interrupting VEGF-induced endothelial cell motility.
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| 2. |
- Hou, Xu, et al.
(författare)
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PDGF-CC blockade inhibits pathological angiogenesis by acting on multiple cellular and molecular targets
- 2010
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 107:27, s. 12216-12221
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Tidskriftsartikel (refereegranskat)abstract
- The importance of identifying VEGF-independent pathways in pathological angiogenesis is increasingly recognized as a result of the emerging drug resistance to anti-VEGF therapies. PDGF-CC is the third member of the PDGF family discovered after more than two decades of studies on PDGF-AA and PDGF-BB. The biological function of PDGF-CC and the underlying cellular and molecular mechanisms remain largely unexplored. Here, using different animal models, we report that PDGF-CC inhibition by neutralizing antibody, shRNA, or genetic deletion suppressed both choroidal and retinal neovascularization. Importantly, we revealed that PDGF-CC targeting acted not only on multiple cell types important for pathological angiogenesis, such as vascular mural and endothelial cells, macrophages, choroidal fibroblasts and retinal pigment epithelial cells, but also on the expression of other important angiogenic genes, such as PDGF-BB and PDGF receptors. At a molecular level, we found that PDGF-CC regulated glycogen synthase kinase (GSK)-3beta phosphorylation and expression both in vitro and in vivo. Activation of GSK3beta impaired PDGF-CC-induced angiogenesis, and inhibition of GSK3beta abolished the antiangiogenic effect of PDGF-CC blockade. Thus, we identified PDGF-CC as an important candidate target gene for antiangiogenic therapy, and PDGF-CC inhibition may be of therapeutic value in treating neovascular diseases.
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| 3. |
- Lee, Chunsik, 1968-
(författare)
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Molecular Mechanisms of Action of Histidine-rich Glycoprotein in Angiogenesis Inhibition
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Angiogenesis, de novo synthesis of blood vessels from the pre-existing vasculature, is required both during embryonic development and in pathophysiological conditions. In particular, tumor growth needs new capillary vessels in order to both deliver oxygen and nutrients and to remove toxin and metabolites. Growth of most solid tumors would be restricted to a microscopic size in the absence of neovascularization. Angiogenesis ensues as a result of a shift in the balance between pro- and anti-angiogenic molecules.Histidine-rich glycoprotein (HRGP) is a heparin-binding plasma protein. We showed that HRGP inhibits endothelial cell migration and adhesion to vitronectin. As a consequence, HRGP attenuates growth and vascularization of mouse model tumors. The anti-angiogenic effect of HRGP is mediated by the central histidine/proline (His/Pro)-rich domain, which must be released from the parent molecule to exert its effect. A 35-amino acid residue peptide denoted HRGP330, derived from the His/Pro-rich domain, was identified as a minimal active anti-angiogenic domain of HRGP. HRGP330 induces disruption of molecular interactions required for cell motility, such as the integrin-linked kinase/paxillin complex. Moreover, HRGP330 inhibits VEGF-induced tyrosine phosphorylation of α-actinin, a focal adhesion kinase (FAK) substrate. Consequently, the motility of endothelial cells is arrested. By use of a signal transduction antibody array, we identified FAK, paxillin and growth factor receptor-bound 2 (Grb2) as tyrosine phosphorylated in HRGP330-treated cells. We confirmed that HRGP targets focal adhesions in endothelial cells, thereby disrupting the cytoskeletal organization and the ability of endothelial cells to assemble into vessel structures. A critical role of FAK in HRGP-inhibition of angiogenesis was validated using a FAK inhibitor, geldanamycin, which allowed rescue of endothelial cell actin rearrangement.We identified another potential mechanism in the HRGP/HRGP330 anti-angiogenic effects, exerted through regulation of tumor-associated macrophages (TAMs). HRGP/HRGP330 treatment led to reduced TAM infiltration, which in turn caused a marked decrease in VEGF and MMP-9 levels in the tumor. Taken together, our present studies show that HRGP/HRGP330 target endothelial cell adhesion, migration, focal adhesions, and furthermore, that HRGP is involved in regulation of macrophage infiltration.
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| 4. |
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| 5. |
- Lee, Chunsik, et al.
(författare)
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Signal transduction in endothelial cells by the angiogenesis inhibitor histidine-rich glycoprotein targets focal adhesions
- 2006
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 0014-4827 .- 1090-2422. ; 312:13, s. 2547-2556
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Tidskriftsartikel (refereegranskat)abstract
- Histidine-rich glycoprotein (HRGP) is an abundant heparin-binding plasma protein. We have shown that a fragment released from the central histidine/proline-rich (His/Pro-rich) domain of HRGP blocks endothelial cell migration in vitro and vascularization and growth of murine fibrosarcoma in vivo. The minimal active HRGP domain exerting the anti-angiogenic effect was recently narrowed down to a 35 amino acid peptide, HRGP330, derived from the His/Pro-rich domain of HRGP. By use of a signal transduction antibody array representing 400 different signal transduction molecules, we now show that HRGP and the synthetic peptide HRGP330 specifically induce tyrosine phosphorylation of focal adhesion kinase and its downstream substrate paxillin in endothelial cells. HRGP/HRGP330 treatment of endothelial cells induced disruption of actin stress fibers, a process reversed by treatment of cells with the FAK inhibitor geldanamycin. In addition, VEGF-mediated endothelial cell tubular morphogenesis in a three-dimensional collagen matrix was inhibited by HRGP and HRGP330. In contrast, VEGF-induced proliferation was not affected by HRGP or HRGP330, demonstrating the central role of cell migration during tube formation. In conclusion, our data show that HRGP targets focal adhesions in endothelial cells, thereby disrupting the cytoskeletal organization and the ability of endothelial cells to assemble into vessel structures.
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| 6. |
- Lee, Chunsik, et al.
(författare)
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Type 3 cystatins : fetuins, kininogen and histidine-rich glycoprotein
- 2009
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Ingår i: Frontiers in Bioscience. - : IMR Press. - 1093-9946 .- 1093-4715. ; 14, s. 2911-2922
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Tidskriftsartikel (refereegranskat)abstract
- This review describes the properties of four structurally related, abundant plasma proteins denoted fetuin-A/alpha-2-Heremans Schmid-glycoprotein (AHSG), fetuin-B (FETUB), kininogen (KNG) and histidine-rich glycoprotein (HRG). These proteins form a subgroup (denoted type 3) within the cystatin superfamily of cysteine protease inhibitors. Apart from KNG, the type 3 proteins appear to lack cystatin activity. AHSG has its major function in regulation of bone mineralization; the physiological role of FETUB is poorly understood. KNG serves dual functions in the assembly of the protein complex initiating the surface-activated blood coagulation cascade and as a precursor for the kinin hormones. The heparin-binding HRG has also been implicated in regulation of coagulation. In addition, several members of the type 3 cystatins have been implicated in tumor growth and shown to regulate endothelial cell function and formation of new blood vessels, angiogenesis. Thus, these proteins may potentially be useful in treatment of diseases characterized by excess angiogenesis such as cancer.
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| 7. |
- Lee, Chunsik, et al.
(författare)
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VEGF-B prevents excessive angiogenesis by inhibiting FGF2/FGFR1 pathway
- 2023
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Ingår i: SIGNAL TRANSDUCTION AND TARGETED THERAPY. - : SPRINGERNATURE. - 2095-9907 .- 2059-3635. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Although VEGF-B was discovered as a VEGF-A homolog a long time ago, the angiogenic effect of VEGF-B remains poorly understood with limited and diverse findings from different groups. Notwithstanding, drugs that inhibit VEGF-B together with other VEGF family members are being used to treat patients with various neovascular diseases. It is therefore critical to have a better understanding of the angiogenic effect of VEGF-B and the underlying mechanisms. Using comprehensive in vitro and in vivo methods and models, we reveal here for the first time an unexpected and surprising function of VEGF-B as an endogenous inhibitor of angiogenesis by inhibiting the FGF2/FGFR1 pathway when the latter is abundantly expressed. Mechanistically, we unveil that VEGF-B binds to FGFR1, induces FGFR1/VEGFR1 complex formation, and suppresses FGF2-induced Erk activation, and inhibits FGF2-driven angiogenesis and tumor growth. Our work uncovers a previously unrecognized novel function of VEGF-B in tethering the FGF2/FGFR1 pathway. Given the anti-angiogenic nature of VEGF-B under conditions of high FGF2/FGFR1 levels, caution is warranted when modulating VEGF-B activity to treat neovascular diseases.
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| 8. |
- Olsson, Anna-Karin, et al.
(författare)
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A fragment of histidine-rich glycoprotein is a potent inhibitor of tumor vascularization
- 2004
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 64:2, s. 599-605
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we show that recombinant human histidine-rich glycoprotein (HRGP) has potent antiangiogenic properties as judged from effects on a syngeneic tumor model in C57/bl6 mice. Growth of fibrosarcoma, a very aggressive tumor, was reduced by >60% by HRGP treatment, and tumor angiogenesis was dramatically decreased. Treatment with HRGP led to increased apoptosis and reduced proliferation in the tumors. In contrast, HRGP did not affect apoptosis or DNA synthesis in endothelial cells or tumor cells in vitro. The mechanism of action of HRGP involves rearrangement of focal adhesions and decreased attachment of endothelial cells to vitronectin and, as a consequence, reduced endothelial cell migration. By using truncated versions of HRGP, we demonstrate that the isolated 150 amino acid-residue His/Pro-rich domain, which is also released by spontaneous proteolysis from purified HRGP, mediates the inhibitory effect on chemotaxis. Moreover, the His/Pro-rich domain must be released from HRGP to exert its effect. This study shows for the first time inhibitory effects of HRGP on tumor vascularization in vivo, thus providing proof of concept that HRGP is an angiogenesis inhibitor.
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| 9. |
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| 10. |
- Tang, Zhongshu, et al.
(författare)
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Survival effect of PDGF-CC rescues neurons from apoptosis in both brain and retina by regulating GSK3β phosphorylation
- 2010
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Ingår i: Journal of Experimental Medicine. - : The Rockefeller University Press. - 0022-1007 .- 1540-9538. ; 207:4, s. 867-880
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Tidskriftsartikel (refereegranskat)abstract
- Platelet-derived growth factor CC (PDGF-CC) is the third member of the PDGF family discovered after more than two decades of studies on the original members of the family, PDGF-AA and PDGF-BB. The biological function of PDGF-CC remains largely to be explored. We report a novel finding that PDGF-CC is a potent neuroprotective factor that acts by modulating glycogen synthase kinase 3beta (GSK3beta) activity. In several different animal models of neuronal injury, such as axotomy-induced neuronal death, neurotoxin-induced neuronal injury, 6-hydroxydopamine-induced Parkinson's dopaminergic neuronal death, and ischemia-induced stroke, PDGF-CC protein or gene delivery protected different types of neurons from apoptosis in both the retina and brain. On the other hand, loss-of-function assays using PDGF-C null mice, neutralizing antibody, or short hairpin RNA showed that PDGF-CC deficiency/inhibition exacerbated neuronal death in different neuronal tissues in vivo. Mechanistically, we revealed that the neuroprotective effect of PDGF-CC was achieved by regulating GSK3beta phosphorylation and expression. Our data demonstrate that PDGF-CC is critically required for neuronal survival and may potentially be used to treat neurodegenerative diseases. Inhibition of the PDGF-CC-PDGF receptor pathway for different clinical purposes should be conducted with caution to preserve normal neuronal functions.
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