Factor XII: New life for an old protein

2010 ◽  
Vol 104 (11) ◽  
pp. 915-918 ◽  
Author(s):  
Gretchen LaRusch ◽  
Alvin Schmaier
Keyword(s):  
Cell Growth ◽  
Knockout Mice ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Antigen Expression ◽  
Mitogen Activated Protein Kinase ◽  
Factor Xii ◽  
Contact Activation ◽  
Urokinase Plasminogen Activator Receptor

SummaryRatnoff and his coworkers recognised that factor XII (XII) stimulates cell growth and activates mitogen-activated protein kinase. We determined the receptor(s) for this function and the consequence of this signalling pathway. Investigations show that the urokinase plasminogen activator receptor serves as the XII binding site on cultured umbilical vein endothelial cells. When XII binds, it stimulates ERK1/2 and Akt S473 phosphorylation. These events are distinct because when cell mTORC2 is absent, XII phosphorylates ERK1/2 but not Akt S473. Zymogen XII is an equal stimulator of signalling as XIIa or inhibitor-treated XIIa. Peptides from uPAR domain 2 block XII binding and ERK1/2 and Akt phosphorylation. Furthermore, antibodies to the integrins β1 and α5 block XII signalling. Likewise, inhibitors to the EGFR block XII-induced phosphorylation events. XII stimulates cell growth and proliferation. XII induces angiogenesis ex vivo in normal aortic sprouts and in vivo in matrigel plugs in normal mice, but not in aorta from uPAR knockout mice or matrigel plugs placed into uPAR-deleted mice. Skin biopsies constitutively or in a wound nine days after injury show reduced CD31 antigen expression in specimens from XII knockout mice compared to wild-type mice. These studies indicate that XII stimulates angiogenesis, a physiologic function independent of contact activation.

High molecular weight kininogen and factor XII binding to endothelial cells and astrocytes

2003 ◽  
Vol 90 (11) ◽  
pp. 787-795 ◽  
Author(s):  
Lawrence Fernando ◽  
Snehlatha Natesan ◽  
Kusumam Joseph ◽  
Allen Kaplan
Keyword(s):  
Molecular Weight ◽  
Endothelial Cells ◽  
High Molecular Weight ◽  
Umbilical Vein ◽  
Microvascular Endothelial Cells ◽  
Factor Xii ◽  
High Molecular Weight Kininogen ◽  
Contact Activation ◽  
Urokinase Plasminogen Activator Receptor ◽  
Microvascular Endothelial

SummaryWe have quantitated the binding of high molecular weight kininogen (HK) to human microvascular endothelial cells of lung and dermal origin as well as to astrocytes and compared the results with those reported for human umbilical vein endothelial cells (HUVEC). We also reassessed parameters of binding to HUVEC employing cells in suspension as well as cells attached to the culture plate and report similar numbers of sites varying from 6.96x105to 7.71x105per cell. The present study shows that HK binds with high specificity and affinity to microvascular endothelial cells (Kd = 1.86 to 4.5 nM) compared to HUVEC (Kd = 10.35nM) but with lower affinity to astrocytes (Kd = 23.73 nM). Human cytokeratin 1, urokinase plasminogen activator receptor and gC1qR were found to be HK binding proteins present at the surface of microvascular endothelial cells and astrocytes analogous to that seen in HUVEC, as assessed by inhibition of binding with antibody to each protein. Lung microvascular endothelial cells had approximately half the number of HK binding sites as HUVEC while dermal micro vascular endothelial cells and astrocytes had only 8-10% of the sites/cell. The affinity of binding to the microvascular endothelial cells was greater than HUVEC, the affinity of binding to astrocytes was considerably less, nevertheless binding to each cell type involves gC1qR, cytokeratin 1 and u-PAR to varying degrees. We also demonstrate, for the first time, that factor XII binds to all of these cell types in a saturable and Zn+2dependent manner. Given that factor XII accelerates the interactions among cell surfaces and proteins of the contact activation cascade to generate bradykinin, binding of factor XII (and the prekallikrein-HK complex) may serve as a mechanism by which these proteins are concentrated locally to facilitate their interactions.

scholarly journals Factor XII stimulates ERK1/2 and Akt through uPAR, integrins, and the EGFR to initiate angiogenesis

Blood ◽  
2010 ◽  
Vol 115 (24) ◽  
pp. 5111-5120 ◽  
Author(s):  
Gretchen A. LaRusch ◽  
Fakhri Mahdi ◽  
Zia Shariat-Madar ◽  
Gregory Adams ◽  
Robert G. Sitrin ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Endothelial Cell ◽  
Umbilical Vein ◽  
Growth Factor Receptor ◽  
Mitogen Activated Protein Kinase ◽  
Endothelial Cell Proliferation ◽  
Factor Xii ◽  
Β1 Integrin ◽  
Urokinase Plasminogen Activator Receptor ◽  
Akt Phosphorylation

Abstract Factor XII (FXII) and high molecular weight kininogen (HK) mutually block each other's binding to the urokinase plasminogen activator receptor (uPAR). We investigated if FXII stimulates cells by interacting with uPAR. FXII (3-62nM) with 0.05mM Zn2+ induces extracellular signal-related kinase 1/2 (ERK1/2; mitogen-activated protein kinase 44 [MAPK44] andMAPK42) and Akt (Ser473) phosphorylation in endothelial cells. FXII-induced phosphorylation of ERK1/2 or Akt is a zymogen activity, not an enzymatic event. ERK1/2 or Akt phosphorylation is blocked upstream by PD98059 or Wortmannin or LY294002, respectively. An uPAR signaling region for FXII is on domain 2 adjacent to uPAR's integrin binding site. Cleaved HK or peptides from HK's domain 5 blocks FXII-induced ERK1/2 and Akt phosphorylation. A β1 integrin peptide that binds uPAR, antibody 6S6 to β1 integrin, or the epidermal growth factor receptor (EGFR) inhibitor AG1478 blocks FXII-induced phosphorylation of ERK1/2 and Akt. FXII induces endothelial cell proliferation and 5-bromo-2′deoxy-uridine incorporation. FXII stimulates aortic sprouting in normal but not uPAR-deficient mouse aorta. FXII produces angiogenesis in matrigel plugs in normal but not uPAR-deficient mice. FXII knockout mice have reduced constitutive and wound-induced blood vessel number. In sum, FXII initiates signaling mediated by uPAR, β1 integrin, and the EGFR to induce human umbilical vein endothelial cell proliferation, growth, and angiogenesis.

scholarly journals Sirt1 deacetylates and stabilizes p62 to promote hepato-carcinogenesis

2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Lifeng Feng ◽  
Miaoqin Chen ◽  
Yiling Li ◽  
Muchun Li ◽  
Shiman Hu ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Overall Survival ◽  
Cell Growth ◽  
Knockout Mice ◽  
Liver Tumors ◽  
Underlying Mechanism ◽  
Carcinoma Cells ◽  
Conditional Knockout

Abstractp62/SQSTM1 is frequently up-regulated in many cancers including hepatocellular carcinoma. Highly expressed p62 promotes hepato-carcinogenesis by activating many signaling pathways including Nrf2, mTORC1, and NFκB signaling. However, the underlying mechanism for p62 up-regulation in hepatocellular carcinoma remains largely unclear. Herein, we confirmed that p62 was up-regulated in hepatocellular carcinoma and its higher expression was associated with shorter overall survival in patients. The knockdown of p62 in hepatocellular carcinoma cells decreased cell growth in vitro and in vivo. Intriguingly, p62 protein stability could be reduced by its acetylation at lysine 295, which was regulated by deacetylase Sirt1 and acetyltransferase GCN5. Acetylated p62 increased its association with the E3 ligase Keap1, which facilitated its poly-ubiquitination-dependent proteasomal degradation. Moreover, Sirt1 was up-regulated to deacetylate and stabilize p62 in hepatocellular carcinoma. Additionally, Hepatocyte Sirt1 conditional knockout mice developed much fewer liver tumors after Diethynitrosamine treatment, which could be reversed by the re-introduction of exogenous p62. Taken together, Sirt1 deacetylates p62 at lysine 295 to disturb Keap1-mediated p62 poly-ubiquitination, thus up-regulating p62 expression to promote hepato-carcinogenesis. Therefore, targeting Sirt1 or p62 is a reasonable strategy for the treatment of hepatocellular carcinoma.

A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

2012 ◽  
Vol 123 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Ting-Hsing Chao ◽  
Shih-Ya Tseng ◽  
Yi-Heng Li ◽  
Ping-Yen Liu ◽  
Chung-Lung Cho ◽  
...  
Keyword(s):  
Protein Kinase ◽  
P38 Mapk ◽  
Umbilical Vein ◽  
Tube Formation ◽  
Mitogen Activated Protein Kinase ◽  
Signalling Pathways ◽  
No Production ◽  
Angiogenic Effect

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

scholarly journals p120 catenin induces opposing effects on tumor cell growth depending on E-cadherin expression

2008 ◽  
Vol 183 (4) ◽  
pp. 737-749 ◽  
Author(s):  
Edwin Soto ◽  
Masahiro Yanagisawa ◽  
Laura A. Marlow ◽  
John A. Copland ◽  
Edith A. Perez ◽  
...  
Keyword(s):  
Cell Growth ◽  
Tumor Cell ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Tumor Cell Growth ◽  
P120 Catenin ◽  
Opposing Effects ◽  
E Cadherin

p120 catenin regulates the activity of the Rho family guanosine triphosphatases (including RhoA and Rac1) in an adhesion-dependent manner. Through this action, p120 promotes a sessile cellular phenotype when associated with epithelial cadherin (E-cadherin) or a motile phenotype when associated with mesenchymal cadherins. In this study, we show that p120 also exerts significant and diametrically opposing effects on tumor cell growth depending on E-cadherin expression. Endogenous p120 acts to stabilize E-cadherin complexes and to actively promote the tumor-suppressive function of E-cadherin, potently inhibiting Ras activation. Upon E-cadherin loss during tumor progression, the negative regulation of Ras is relieved; under these conditions, endogenous p120 promotes transformed cell growth both in vitro and in vivo by activating a Rac1–mitogen-activated protein kinase signaling pathway normally activated by the adhesion of cells to the extracellular matrix. These data indicate that both E-cadherin and p120 are important regulators of tumor cell growth and imply roles for both proteins in chemoresistance and targeted therapeutics.

scholarly journals A mechanism for hereditary angioedema with normal C1 inhibitor: an inhibitory regulatory role for the factor XII heavy chain

Blood ◽  
2019 ◽  
Vol 133 (10) ◽  
pp. 1152-1163 ◽  
Author(s):  
Ivan Ivanov ◽  
Anton Matafonov ◽  
Mao-fu Sun ◽  
Bassem M. Mohammed ◽  
Qiufang Cheng ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Hereditary Angioedema ◽  
Catalytic Efficiency ◽  
Regulatory Function ◽  
Factor Xii ◽  
C1 Inhibitor ◽  
Contact Activation ◽  
Inhibitory Function

Abstract The plasma proteins factor XII (FXII) and prekallikrein (PK) undergo reciprocal activation to the proteases FXIIa and kallikrein by a process that is enhanced by surfaces (contact activation) and regulated by the serpin C1 inhibitor. Kallikrein cleaves high-molecular-weight kininogen (HK), releasing the vasoactive peptide bradykinin. Patients with hereditary angioedema (HAE) experience episodes of soft tissue swelling as a consequence of unregulated kallikrein activity or increased prekallikrein activation. Although most HAE cases are caused by reduced plasma C1-inhibitor activity, HAE has been linked to lysine/arginine substitutions for Thr309 in FXII (FXII-Lys/Arg309). Here, we show that FXII-Lys/Arg309 is susceptible to cleavage after residue 309 by coagulation proteases (thrombin and FXIa), resulting in generation of a truncated form of FXII (δFXII). The catalytic efficiency of δFXII activation by kallikrein is 15-fold greater than for full-length FXII. The enhanced rate of reciprocal activation of PK and δFXII in human plasma and in mice appears to overwhelm the normal inhibitory function of C1 inhibitor, leading to increased HK cleavage. In mice given human FXII-Lys/Arg309, induction of thrombin generation by infusion of tissue factor results in enhanced HK cleavage as a consequence of δFXII formation. The effects of δFXII in vitro and in vivo are reproduced when wild-type FXII is bound by an antibody to the FXII heavy chain (HC; 15H8). The results contribute to our understanding of the predisposition of patients carrying FXII-Lys/Arg309 to angioedema after trauma, and reveal a regulatory function for the FXII HC that normally limits PK activation in plasma.

SECONDARY FIBRINOLYSIS, PROTEIN C ACTIVATION, PLATELET DECREASE, BUT NOT CONTACT ACTIVATION CAN BE CORRELATED TO FREE THROMBIN ACTION IN EXPERIMENTAL DIC

1987 ◽  
Author(s):  
G A Marbet ◽  
P Satiropas ◽  
C Pantaleoni ◽  
F Duckert
Keyword(s):  
Protein C ◽  
Defense Mechanisms ◽  
Dermatan Sulfate ◽  
Correlation Coefficients ◽  
Factor Xii ◽  
Spearman Correlation ◽  
Contact Activation ◽  
Defence Mechanisms ◽  
Tissue Thromboplastin

We have studied the influence of activated coagulation on antithrombotic defence mechanisms in vivo. Conventional coagulation variables, platelets (Tcy), plasminogen (Pig), α2-antiplasmin (AP) , protein C (PC), factor VIII C, factor XII and Cl-inhibitor have been measured before and during reversible tissue thromboplastin-induced DIC in the dog. Free thrombin action as derived from fibrinogen (Fbg) decrease has been expressed as integral of active thrombin concentration over time (φ). Protection by heparin H, pentosan polysulfate PPS or dermatan sulfate DS was studied. DIC had no consistent effect on the behaviour of factor XII and Cl-inhibitor, but led to the consumption (Δ) of the following variables:The Spearman correlation coefficients between and φ in the Δ whole group were all statistically significant and ranged from rs=0.51 (ΔPlg) to rs =0.94 (ΔFbg). The response of major defense mechanisms in vivo quantitatively depends on active thrombin.

Aloe Metabolites Prevent LPS-Induced Sepsis and Inflammatory Response by Inhibiting Mitogen-Activated Protein Kinase Activation

2017 ◽  
Vol 45 (04) ◽  
pp. 847-861 ◽  
Author(s):  
Chia-Yang Li ◽  
Katsuhiko Suzuki ◽  
Yung-Li Hung ◽  
Meng-Syuan Yang ◽  
Chung-Ping Yu ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Aloe Vera ◽  
Peritoneal Macrophages ◽  
Mitogen Activated Protein Kinase ◽  
Protective Effects ◽  
Raw264.7 Macrophages ◽  
Mitogen Activated Protein ◽  
Anti Inflammatory

Aloe, a polyphenolic anthranoid-containing Aloe vera leaves, is a Chinese medicine and a popular dietary supplement worldwide. In in vivo situations, polyphenolic anthranoids are extensively broken down into glucuronides and sulfate metabolites by the gut and the liver. The anti-inflammatory potential of aloe metabolites has not been examined. The aim of this study was to investigate the anti-inflammatory effects of aloe metabolites from in vitro (lipopolysaccharides (LPS)-activated RAW264.7 macrophages) and ex vivo (LPS-activated peritoneal macrophages) to in vivo (LPS-induced septic mice). The production of proinflammatory cytokines (TNF-[Formula: see text] and IL-12) and NO was determined by ELISA and Griess reagents, respectively. The expression levels of iNOS and MAPKs were analyzed by Western blot. Our results showed that aloe metabolites inhibited the expression of iNOS, decreased the production of TNF-[Formula: see text], IL-12, and NO, and suppressed the phosphorylation of MAPKs by LPS-activated RAW264.7 macrophages. In addition, aloe metabolites reduced the production of NO, TNF-[Formula: see text] and IL-12 by murine peritoneal macrophages. Furthermore, aloe administration significantly reduced the NO level and exhibited protective effects against sepsis-related death in LPS-induced septic mice. These results suggest that aloe metabolites exerted anti-inflammatory effects in vivo, and that these effects were associated with the inhibition of inflammatory mediators. Therefore, aloe could be considered an effective therapeutic agent for the treatment of sepsis.

scholarly journals Role of the captured retroviral envelope syncytin-B gene in the fusion of osteoclast and giant cell precursors and in bone resorption, analyzed ex vivo and in vivo in syncytin-B knockout mice

Bone Reports ◽  
2019 ◽  
Vol 11 ◽  
pp. 100214 ◽  
Author(s):  
Amélie E. Coudert ◽  
François Redelsperger ◽  
Yasmine Chabbi-Achengli ◽  
Cécile Vernochet ◽  
Caroline Marty ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Giant Cell ◽  
Knockout Mice ◽  
Ex Vivo

scholarly journals OP32 Mincle signalling promotes intestinal mucosal inflammation through induction of macrophage pyroptosis and neutrophil chemotaxis in Crohn’s disease

2020 ◽  
Vol 14 (Supplement_1) ◽  
pp. S031-S031
Author(s):  
W GONG ◽  
K Guo ◽  
J Ren
Keyword(s):  
Intestinal Inflammation ◽  
Ex Vivo ◽  
Experimental Colitis ◽  
Mitogen Activated Protein Kinase ◽  
Mucosal Inflammation ◽  
Neutrophil Chemotaxis ◽  
Knock Out ◽  
Mitogen Activated Protein ◽  
Proinflammatory Role

Abstract Background Macrophage-inducible C-type lectin (Mincle) signalling plays a proinflammatory role in different organs such as the brain and liver, but its role in intestinal inflammation remains unknown. Methods We studied the characteristics of Mincle signalling expression in CD patients and experimental colitis. The functional role of Mincle signalling in the intestine was addressed in experimental colitis models in vivo by using mice with Mincle knock out (Mincle−/−), neutralising anti-Mincle antibody, Mincle pharmacologic agonist and RNA-seq genome expression analysis. Bone marrow-derived macrophages were collected from mice and used to further verify the effect of Mincle signalling in macrophages. Results Mincle signalling was significantly elevated in active human CD and experimental colitis, and macrophages were the principal leukocyte subset that up-regulates Mincle signalling. Mincle deficiency ameliorated the colitis by reducing induced macrophage pyroptosis (Figure 1), whereas activation of Mincle with the pharmacologic agonist worsened the intestinal inflammation (Figure 2). Moreover, the ex vivo studies confirmed that Mincle signalling activation promoted and its absence restricted release of proinflammatory cytokines from pyroptosis of macrophage (Figure 3). Finally, Mincle/Syk signalling could promote the production of chemokines to recruit neutrophils by activating Mitogen-Activated Protein Kinase (MAPK) during inflammation (Figure 4). Conclusion Mincle signalling promotes intestinal mucosal inflammation through induction of macrophage pyroptosis and neutrophil chemotaxis. Modulation of the Mincle/Syk axis emerges as a potential therapeutic strategy to target inflammation and treat CD.

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