Bradley Rabquer | Albion College (original) (raw)

Papers by Bradley Rabquer

International Journal of Clinical Rheumatology, 2012

Nature reviews. Rheumatology, 2014

Current rheumatology reports, 2012

Systemic sclerosis (scleroderma [SSc]) is a multifactorial disease characterized by inflammation,... more Systemic sclerosis (scleroderma [SSc]) is a multifactorial disease characterized by inflammation, extensive and progressive fibrosis, and multiple vasculopathies. The vascular manifestations can be seen early in the pathogenesis of the disease and include malformed capillaries, Raynaud's phenomenon, and digital ulcers. As the disease progresses, the vasculopathy proceeds to significant clinical manifestations, including renal crisis and pulmonary arterial hypertension. Moreover, later stages of the disease are marked by increasingly avascular areas. Despite the obliteration of microvascular structures, compensatory vasculogenesis and angiogenesis do not occur normally. This is in spite of a general increase in many potent angiogenic factors. Recent studies are beginning to examine this paradox and subsequent paucity of an angiogenic response in SSc. In this review, we discuss these findings and examine the role that chemokine and growth factor receptors, proteases, adhesion mole...

Rheumatology, 2009

Objective. SSc is characterized by microvascular abnormalities and leucocyte infiltration. Previo... more Objective. SSc is characterized by microvascular abnormalities and leucocyte infiltration. Previous studies have suggested a proadhesive phenotype in SSc skin, but the functional consequences of this phenotype are not fully understood. Molecules known to mediate leucocyte adhesion include those present at intracellular junctions, such as junctional adhesion molecule-B (JAM-B), JAM-C and CD99, as well as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). The aim of this study was to examine adhesive interactions in SSc skin.

Proceedings of the National Academy of Sciences, 2008

Regulation of IL-6 transsignaling by the administration of soluble gp130 (sgp130) receptor to cap... more Regulation of IL-6 transsignaling by the administration of soluble gp130 (sgp130) receptor to capture the IL-6/soluble IL-6R complex has shown promise for the treatment of rheumatoid arthritis (RA). However, enhancing endogenous sgp130 via alternative splicing of the gp130 gene has not yet been tested. We found that epigallocatechin-3-gallate (EGCG), an anti-inflammatory compound found in green tea, inhibits IL-1␤-induced IL-6 production and transsignaling in RA synovial fibroblasts by inducing alternative splicing of gp130 mRNA, resulting in enhanced sgp130 production. Results from in vivo studies using a rat adjuvant-induced arthritis model showed specific inhibition of IL-6 levels in the serum and joints of EGCG-treated rats by 28% and 40%, respectively, with concomitant amelioration of rat adjuvant-induced arthritis. We also observed a marked decrease in membrane-bound gp130 protein expression in the joint homogenates of the EGCG-treated group. In contrast, quantitative RT-PCR showed that the gp130/IL-6R␣ mRNA ratio increased by ϳ2-fold, suggesting a possible mechanism of sgp130 activation by EGCG. Gelatin zymography results showed EGCG inhibits IL-6/soluble IL-6R-induced matrix metalloproteinase-2 activity in RA synovial fibroblasts and in joint homogenates, possibly via up-regulation of sgp130 synthesis. The results of these studies provide previously undescribed evidence of IL-6 synthesis and transsignaling inhibition by EGCG with a unique mechanism of sgp130 up-regulation, and thus hold promise as a potential therapeutic agent for RA. rheumatoid arthritis ͉ alternative splicing ͉ cytokine therapy ͉ pharmacology ͉ therapeutics Tissue Processing. Ankles from the PBS-and EGCG-treated groups were processed for ELISA and Western blotting as described in SI Materials and Methods.

Arthritis Research & Therapy, 2011

Introduction: Systemic sclerosis (SSc) is characterized by fibrosis and microvascular abnormaliti... more Introduction: Systemic sclerosis (SSc) is characterized by fibrosis and microvascular abnormalities including dysregulated angiogenesis. Chemokines, in addition to their chemoattractant properties, have the ability to modulate angiogenesis. Chemokines lacking the enzyme-linked receptor (ELR) motif, such as monokine induced by interferon-γ (IFN-γ) (MIG/CXCL9) and IFN-inducible protein 10 (IP-10/CXCL10), inhibit angiogenesis by binding CXCR3. In addition, CXCL16 promotes angiogenesis by binding its unique receptor CXCR6. In this study, we determined the expression of these chemokines and receptors in SSc skin and serum. Methods: Immunohistology and enzyme-linked immunosorbent assays (ELISAs) were used to determine chemokine and chemokine receptor expression in the skin and serum, respectively, of SSc and normal patients. Endothelial cells (ECs) were isolated from SSc skin biopsies and chemokine and chemokine receptor expression was determined by quantitative PCR and immunofluorescence staining. Results: Antiangiogenic IP-10/CXCL10 and MIG/CXCL9 were elevated in SSc serum and highly expressed in SSc skin. However, CXCR3, the receptor for these chemokines, was decreased on ECs in SSc vs. normal skin. CXCL16 was elevated in SSc serum and increased in SSc patients with early disease, pulmonary arterial hypertension, and those that died during the 36 months of the study. In addition, its receptor CXCR6 was overexpressed on ECs in SSc skin. At the mRNA and protein levels, CXCR3 was decreased while CXCR6 was increased on SSc ECs vs. human microvascular endothelial cells (HMVECs). Conclusions: These results show that while the expression of MIG/CXCL9 and IP-10/CXCL10 are elevated in SSc serum, the expression of CXCR3 is downregulated on SSc dermal ECs. In contrast, CXCL16 and CXCR6 are elevated in SSc serum and on SSc dermal ECs, respectively. In all, these findings suggest angiogenic chemokine receptor expression is likely regulated in an effort to promote angiogenesis in SSc skin.

Arthritis & Rheumatism, 2012

In vitro studies indicate that type I interferons (IFNs) may play prominent roles in increased CV... more In vitro studies indicate that type I interferons (IFNs) may play prominent roles in increased CV risk in SLE. However, the in vivo relevance of these findings, with regard to the development of CVD, has not been characterized. This study was undertaken to examine the role of type I IFNs in endothelial dysfunction, aberrant vascular repair, and atherothrombosis in murine models of lupus and atherosclerosis.

Arthritis & Rheumatism, 2011

Methods. TNF␣-induced IRF-1 expression was assessed by real-time quantitative polymerase chain re... more Methods. TNF␣-induced IRF-1 expression was assessed by real-time quantitative polymerase chain reaction and Western blotting. The effect of TNF␣ on IRF-1 was assessed using nuclear and cytoplasmic extracts, Western blots, and immunofluorescence. Chemical inhibitors of NF-B or MAP kinases were used to analyze the signaling pathways of TNF␣induced IRF-1 expression and IRF-1 nuclear translocation. Control and IRF-1 small interfering RNA (siRNA) were used to analyze the effect of IRF-1 down-regulation on TNF␣-induced IL-18BP expression. IL-18BPa ex-pression was assessed by enzyme-linked immunosorbent assay, and IL-18 was assessed at the transcription and bioactivity levels using KG-1 cells.

Arthritis & Rheumatism, 2010

Objective-To better define the activity of soluble CXCL16 to recruit polymorphonuclear cells (PMN... more Objective-To better define the activity of soluble CXCL16 to recruit polymorphonuclear cells (PMNs) in vivo, we developed a novel animal model of gout pathology. We tested CXCL16 to recruit PMNs in a human normal synovial tissue (NL ST) severe combined immunodeficient (SCID) mouse chimera injected intragraft with gouty SF.

Arthritis & Rheumatism, 2008

Annals of the Rheumatic Diseases, 2014

Angiogenesis contributes to the pathogenesis of rheumatoid arthritis. Fucosyltransferases (Futs) ... more Angiogenesis contributes to the pathogenesis of rheumatoid arthritis. Fucosyltransferases (Futs) are involved in angiogenesis and tumour growth. Here, we examined the role of Fut1 in angiogenesis and K/BxN serum transfer arthritis. We examined Fut1 expression in human dermal microvascular endothelial cells (HMVECs) by quantitative PCR. We performed a number of angiogenesis assays to determine the role of Fut1 using HMVECs, Fut1 null (Fut1(-/-)), and wild type (wt) endothelial cells (ECs) and mice. K/BxN serum transfer arthritis was performed to determine the contribution of Fut1-mediated angiogenesis in Fut1(-/-) and wt mice. A static adhesion assay was implemented with RAW264.7 (mouse macrophage cell line) and mouse ECs. Quantitative PCR, immunofluorescence and flow cytometry were performed with Fut1(-/-) and wt ECs for adhesion molecule expression. Tumour necrosis factor-α induced Fut1 mRNA and protein expression in HMVECs. HMVECs transfected with Fut1 antisense oligodeoxynucleotide and Fut1(-/-) ECs formed significantly fewer tubes on Matrigel. Fut1(-/-) mice had reduced angiogenesis in Matrigel plug and sponge granuloma angiogenesis assays compared with wt mice. Fut1(-/-) mice were resistant to K/BxN serum transfer arthritis and had decreased angiogenesis and leucocyte ingress into inflamed joints. Adhesion of RAW264.7 cells to wt mouse ECs was significantly reduced when Fut1 was lacking. Fut1(-/-) ECs had decreased intercellular adhesion molecule-1 (ICAM-1) expression at mRNA and protein levels compared with wt ECs. ICAM-1 was also decreased in Fut1(-/-) arthritic ankle cryosections compared with wt ankles. Fut1 plays an important role in regulating angiogenesis and ICAM-1 expression in inflammatory arthritis.

Annals of the Rheumatic Diseases, 2011

Background and objectivesInterleukin 18 (IL-18) is a pleiotropic cytokine involved in rheumatoid ... more Background and objectivesInterleukin 18 (IL-18) is a pleiotropic cytokine involved in rheumatoid arthritis (RA) pathogenesis. This study was carried out to evaluate the efficacy of IL-18 binding protein (IL-18BP) gene therapy in the rat adjuvant-induced arthritis (AIA) model and to decipher the mechanisms by which IL-18BP delivery lessens bone destruction.Materials and methodsArthritis was induced in female Lewis rat by Mycobacterium

Annals of the Rheumatic Diseases, 2010

Interleukin 18 (IL-18) is a novel mediator of angiogenesis in rheumatoid arthritis (RA). To exami... more Interleukin 18 (IL-18) is a novel mediator of angiogenesis in rheumatoid arthritis (RA). To examine the role of IL-18 in RA angiogenesis and the signalling mechanisms involved. Human dermal microvascular endothelial cell (HMVEC) chemotaxis, capillary morphogenesis assays and Matrigel plug angiogenesis assays were performed in vivo using IL-18 with or without signalling inhibitors. A novel model of angiogenesis was devised using dye-tagged HMVECs to study their homing into RA and normal (NL) synovial tissues (STs) engrafted in severe combined immunodeficient (SCID) mice. IL-18-mediated angiogenesis depended on Src and Jnk, as the inhibitors of Src and Jnk blocked IL-18-induced HMVEC chemotaxis, tube formation and angiogenesis in Matrigel plugs. However, inhibitors of Janus kinase 2, p38, MEK, phosphatidylinositol-3-kinase and neutralising antibodies to vascular endothelial growth factor or stromal derived factor-1α did not alter IL-18-induced HMVEC migration. These results were confirmed with Jnk or Src sense or antisense oligodeoxynucleotides. Moreover, IL-18 induced phosphorylation of Src and Jnk in HMVECs. As proof of principle, IL-18 null mice had a significantly decreased angiogenesis compared with wild-type mice in Matrigel plug angiogenesis assays in vivo. IL-18 markedly enhanced mature HMVEC homing to human RA ST compared with NL ST in SCID mice, confirming the role of IL-18-induced angiogenesis in RA ST in vivo. Targeting IL-18 or its signalling intermediates may prove to be a potentially novel therapeutic strategy for angiogenesis-dependent diseases, such as RA.

Annals of the Rheumatic Diseases, 2010

Methods-Biopsies from proximal and distal arm skin and serum were obtained from patients with SSc... more Methods-Biopsies from proximal and distal arm skin and serum were obtained from patients with SSc and normal (NL) volunteers. To determine the expression of JAM-A on SSc dermal fibroblasts and in SSc skin, cell surface ELISAs and immunohistology were performed. An ELISA was designed to determine the amount of soluble JAM-A (sJAM-A) in serum. Myeloid U937 cell-SSc dermal fibroblast and skin adhesion assays were performed to determine the role of JAM-A in myeloid cell adhesion.

The Journal of Immunology, 2010

Junctional adhesion molecule-C (JAM-C) is an adhesion molecule expressed by endothelial cells (EC... more Junctional adhesion molecule-C (JAM-C) is an adhesion molecule expressed by endothelial cells (ECs) that plays a role in tight junction formation, leukocyte adhesion, and transendothelial migration. In the current study, we investigated whether JAM-C is found in soluble form and whether soluble JAM-C (sJAM-C) mediates angiogenesis. We found that JAM-C is present in soluble form in normal serum and elevated in rheumatoid arthritis (RA) serum. The concentration of sJAM-C is also elevated locally in RA synovial fluid compared with RA serum or osteoarthritis synovial fluid. sJAM-C was also present in the culture supernatant of human microvascular ECs (HMVECs) and immortalized human dermal microvascular ECs, and its concentration was increased following cytokine stimulation. In addition, sJAM-C cleavage from the cell surface was mediated in part by a disintegrin and metalloproteinases 10 and 17. In functional assays, sJAM-C was both chemotactic and chemokinetic for HMVECs and induced HMVEC tube formation on Matrigel in vitro. Neutralizing anti-JAM-C Abs inhibited RA synovial fluid-induced HMVEC chemotaxis and sJAM-C-induced HMVEC tube formation on Matrigel. sJAM-C also induced angiogenesis in vivo in the Matrigel plug and sponge granuloma models. Moreover, sJAM-C-mediated HMVEC chemotaxis was dependent on Src, p38, and PI3K. Our results show that JAM-C exists in soluble form and suggest that modulation of sJAM-C may provide a novel route for controlling pathological angiogenesis.

International Journal of Clinical Rheumatology, 2012

Nature reviews. Rheumatology, 2014

Current rheumatology reports, 2012

Systemic sclerosis (scleroderma [SSc]) is a multifactorial disease characterized by inflammation,... more Systemic sclerosis (scleroderma [SSc]) is a multifactorial disease characterized by inflammation, extensive and progressive fibrosis, and multiple vasculopathies. The vascular manifestations can be seen early in the pathogenesis of the disease and include malformed capillaries, Raynaud's phenomenon, and digital ulcers. As the disease progresses, the vasculopathy proceeds to significant clinical manifestations, including renal crisis and pulmonary arterial hypertension. Moreover, later stages of the disease are marked by increasingly avascular areas. Despite the obliteration of microvascular structures, compensatory vasculogenesis and angiogenesis do not occur normally. This is in spite of a general increase in many potent angiogenic factors. Recent studies are beginning to examine this paradox and subsequent paucity of an angiogenic response in SSc. In this review, we discuss these findings and examine the role that chemokine and growth factor receptors, proteases, adhesion mole...

Rheumatology, 2009

Objective. SSc is characterized by microvascular abnormalities and leucocyte infiltration. Previo... more Objective. SSc is characterized by microvascular abnormalities and leucocyte infiltration. Previous studies have suggested a proadhesive phenotype in SSc skin, but the functional consequences of this phenotype are not fully understood. Molecules known to mediate leucocyte adhesion include those present at intracellular junctions, such as junctional adhesion molecule-B (JAM-B), JAM-C and CD99, as well as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). The aim of this study was to examine adhesive interactions in SSc skin.

Proceedings of the National Academy of Sciences, 2008

Regulation of IL-6 transsignaling by the administration of soluble gp130 (sgp130) receptor to cap... more Regulation of IL-6 transsignaling by the administration of soluble gp130 (sgp130) receptor to capture the IL-6/soluble IL-6R complex has shown promise for the treatment of rheumatoid arthritis (RA). However, enhancing endogenous sgp130 via alternative splicing of the gp130 gene has not yet been tested. We found that epigallocatechin-3-gallate (EGCG), an anti-inflammatory compound found in green tea, inhibits IL-1␤-induced IL-6 production and transsignaling in RA synovial fibroblasts by inducing alternative splicing of gp130 mRNA, resulting in enhanced sgp130 production. Results from in vivo studies using a rat adjuvant-induced arthritis model showed specific inhibition of IL-6 levels in the serum and joints of EGCG-treated rats by 28% and 40%, respectively, with concomitant amelioration of rat adjuvant-induced arthritis. We also observed a marked decrease in membrane-bound gp130 protein expression in the joint homogenates of the EGCG-treated group. In contrast, quantitative RT-PCR showed that the gp130/IL-6R␣ mRNA ratio increased by ϳ2-fold, suggesting a possible mechanism of sgp130 activation by EGCG. Gelatin zymography results showed EGCG inhibits IL-6/soluble IL-6R-induced matrix metalloproteinase-2 activity in RA synovial fibroblasts and in joint homogenates, possibly via up-regulation of sgp130 synthesis. The results of these studies provide previously undescribed evidence of IL-6 synthesis and transsignaling inhibition by EGCG with a unique mechanism of sgp130 up-regulation, and thus hold promise as a potential therapeutic agent for RA. rheumatoid arthritis ͉ alternative splicing ͉ cytokine therapy ͉ pharmacology ͉ therapeutics Tissue Processing. Ankles from the PBS-and EGCG-treated groups were processed for ELISA and Western blotting as described in SI Materials and Methods.

Arthritis Research & Therapy, 2011

Introduction: Systemic sclerosis (SSc) is characterized by fibrosis and microvascular abnormaliti... more Introduction: Systemic sclerosis (SSc) is characterized by fibrosis and microvascular abnormalities including dysregulated angiogenesis. Chemokines, in addition to their chemoattractant properties, have the ability to modulate angiogenesis. Chemokines lacking the enzyme-linked receptor (ELR) motif, such as monokine induced by interferon-γ (IFN-γ) (MIG/CXCL9) and IFN-inducible protein 10 (IP-10/CXCL10), inhibit angiogenesis by binding CXCR3. In addition, CXCL16 promotes angiogenesis by binding its unique receptor CXCR6. In this study, we determined the expression of these chemokines and receptors in SSc skin and serum. Methods: Immunohistology and enzyme-linked immunosorbent assays (ELISAs) were used to determine chemokine and chemokine receptor expression in the skin and serum, respectively, of SSc and normal patients. Endothelial cells (ECs) were isolated from SSc skin biopsies and chemokine and chemokine receptor expression was determined by quantitative PCR and immunofluorescence staining. Results: Antiangiogenic IP-10/CXCL10 and MIG/CXCL9 were elevated in SSc serum and highly expressed in SSc skin. However, CXCR3, the receptor for these chemokines, was decreased on ECs in SSc vs. normal skin. CXCL16 was elevated in SSc serum and increased in SSc patients with early disease, pulmonary arterial hypertension, and those that died during the 36 months of the study. In addition, its receptor CXCR6 was overexpressed on ECs in SSc skin. At the mRNA and protein levels, CXCR3 was decreased while CXCR6 was increased on SSc ECs vs. human microvascular endothelial cells (HMVECs). Conclusions: These results show that while the expression of MIG/CXCL9 and IP-10/CXCL10 are elevated in SSc serum, the expression of CXCR3 is downregulated on SSc dermal ECs. In contrast, CXCL16 and CXCR6 are elevated in SSc serum and on SSc dermal ECs, respectively. In all, these findings suggest angiogenic chemokine receptor expression is likely regulated in an effort to promote angiogenesis in SSc skin.

Arthritis & Rheumatism, 2012

In vitro studies indicate that type I interferons (IFNs) may play prominent roles in increased CV... more In vitro studies indicate that type I interferons (IFNs) may play prominent roles in increased CV risk in SLE. However, the in vivo relevance of these findings, with regard to the development of CVD, has not been characterized. This study was undertaken to examine the role of type I IFNs in endothelial dysfunction, aberrant vascular repair, and atherothrombosis in murine models of lupus and atherosclerosis.

Arthritis & Rheumatism, 2011

Methods. TNF␣-induced IRF-1 expression was assessed by real-time quantitative polymerase chain re... more Methods. TNF␣-induced IRF-1 expression was assessed by real-time quantitative polymerase chain reaction and Western blotting. The effect of TNF␣ on IRF-1 was assessed using nuclear and cytoplasmic extracts, Western blots, and immunofluorescence. Chemical inhibitors of NF-B or MAP kinases were used to analyze the signaling pathways of TNF␣induced IRF-1 expression and IRF-1 nuclear translocation. Control and IRF-1 small interfering RNA (siRNA) were used to analyze the effect of IRF-1 down-regulation on TNF␣-induced IL-18BP expression. IL-18BPa ex-pression was assessed by enzyme-linked immunosorbent assay, and IL-18 was assessed at the transcription and bioactivity levels using KG-1 cells.

Arthritis & Rheumatism, 2010

Objective-To better define the activity of soluble CXCL16 to recruit polymorphonuclear cells (PMN... more Objective-To better define the activity of soluble CXCL16 to recruit polymorphonuclear cells (PMNs) in vivo, we developed a novel animal model of gout pathology. We tested CXCL16 to recruit PMNs in a human normal synovial tissue (NL ST) severe combined immunodeficient (SCID) mouse chimera injected intragraft with gouty SF.

Arthritis & Rheumatism, 2008

Annals of the Rheumatic Diseases, 2014

Angiogenesis contributes to the pathogenesis of rheumatoid arthritis. Fucosyltransferases (Futs) ... more Angiogenesis contributes to the pathogenesis of rheumatoid arthritis. Fucosyltransferases (Futs) are involved in angiogenesis and tumour growth. Here, we examined the role of Fut1 in angiogenesis and K/BxN serum transfer arthritis. We examined Fut1 expression in human dermal microvascular endothelial cells (HMVECs) by quantitative PCR. We performed a number of angiogenesis assays to determine the role of Fut1 using HMVECs, Fut1 null (Fut1(-/-)), and wild type (wt) endothelial cells (ECs) and mice. K/BxN serum transfer arthritis was performed to determine the contribution of Fut1-mediated angiogenesis in Fut1(-/-) and wt mice. A static adhesion assay was implemented with RAW264.7 (mouse macrophage cell line) and mouse ECs. Quantitative PCR, immunofluorescence and flow cytometry were performed with Fut1(-/-) and wt ECs for adhesion molecule expression. Tumour necrosis factor-α induced Fut1 mRNA and protein expression in HMVECs. HMVECs transfected with Fut1 antisense oligodeoxynucleotide and Fut1(-/-) ECs formed significantly fewer tubes on Matrigel. Fut1(-/-) mice had reduced angiogenesis in Matrigel plug and sponge granuloma angiogenesis assays compared with wt mice. Fut1(-/-) mice were resistant to K/BxN serum transfer arthritis and had decreased angiogenesis and leucocyte ingress into inflamed joints. Adhesion of RAW264.7 cells to wt mouse ECs was significantly reduced when Fut1 was lacking. Fut1(-/-) ECs had decreased intercellular adhesion molecule-1 (ICAM-1) expression at mRNA and protein levels compared with wt ECs. ICAM-1 was also decreased in Fut1(-/-) arthritic ankle cryosections compared with wt ankles. Fut1 plays an important role in regulating angiogenesis and ICAM-1 expression in inflammatory arthritis.

Annals of the Rheumatic Diseases, 2011

Background and objectivesInterleukin 18 (IL-18) is a pleiotropic cytokine involved in rheumatoid ... more Background and objectivesInterleukin 18 (IL-18) is a pleiotropic cytokine involved in rheumatoid arthritis (RA) pathogenesis. This study was carried out to evaluate the efficacy of IL-18 binding protein (IL-18BP) gene therapy in the rat adjuvant-induced arthritis (AIA) model and to decipher the mechanisms by which IL-18BP delivery lessens bone destruction.Materials and methodsArthritis was induced in female Lewis rat by Mycobacterium

Annals of the Rheumatic Diseases, 2010

Interleukin 18 (IL-18) is a novel mediator of angiogenesis in rheumatoid arthritis (RA). To exami... more Interleukin 18 (IL-18) is a novel mediator of angiogenesis in rheumatoid arthritis (RA). To examine the role of IL-18 in RA angiogenesis and the signalling mechanisms involved. Human dermal microvascular endothelial cell (HMVEC) chemotaxis, capillary morphogenesis assays and Matrigel plug angiogenesis assays were performed in vivo using IL-18 with or without signalling inhibitors. A novel model of angiogenesis was devised using dye-tagged HMVECs to study their homing into RA and normal (NL) synovial tissues (STs) engrafted in severe combined immunodeficient (SCID) mice. IL-18-mediated angiogenesis depended on Src and Jnk, as the inhibitors of Src and Jnk blocked IL-18-induced HMVEC chemotaxis, tube formation and angiogenesis in Matrigel plugs. However, inhibitors of Janus kinase 2, p38, MEK, phosphatidylinositol-3-kinase and neutralising antibodies to vascular endothelial growth factor or stromal derived factor-1α did not alter IL-18-induced HMVEC migration. These results were confirmed with Jnk or Src sense or antisense oligodeoxynucleotides. Moreover, IL-18 induced phosphorylation of Src and Jnk in HMVECs. As proof of principle, IL-18 null mice had a significantly decreased angiogenesis compared with wild-type mice in Matrigel plug angiogenesis assays in vivo. IL-18 markedly enhanced mature HMVEC homing to human RA ST compared with NL ST in SCID mice, confirming the role of IL-18-induced angiogenesis in RA ST in vivo. Targeting IL-18 or its signalling intermediates may prove to be a potentially novel therapeutic strategy for angiogenesis-dependent diseases, such as RA.

Annals of the Rheumatic Diseases, 2010

Methods-Biopsies from proximal and distal arm skin and serum were obtained from patients with SSc... more Methods-Biopsies from proximal and distal arm skin and serum were obtained from patients with SSc and normal (NL) volunteers. To determine the expression of JAM-A on SSc dermal fibroblasts and in SSc skin, cell surface ELISAs and immunohistology were performed. An ELISA was designed to determine the amount of soluble JAM-A (sJAM-A) in serum. Myeloid U937 cell-SSc dermal fibroblast and skin adhesion assays were performed to determine the role of JAM-A in myeloid cell adhesion.

The Journal of Immunology, 2010

Junctional adhesion molecule-C (JAM-C) is an adhesion molecule expressed by endothelial cells (EC... more Junctional adhesion molecule-C (JAM-C) is an adhesion molecule expressed by endothelial cells (ECs) that plays a role in tight junction formation, leukocyte adhesion, and transendothelial migration. In the current study, we investigated whether JAM-C is found in soluble form and whether soluble JAM-C (sJAM-C) mediates angiogenesis. We found that JAM-C is present in soluble form in normal serum and elevated in rheumatoid arthritis (RA) serum. The concentration of sJAM-C is also elevated locally in RA synovial fluid compared with RA serum or osteoarthritis synovial fluid. sJAM-C was also present in the culture supernatant of human microvascular ECs (HMVECs) and immortalized human dermal microvascular ECs, and its concentration was increased following cytokine stimulation. In addition, sJAM-C cleavage from the cell surface was mediated in part by a disintegrin and metalloproteinases 10 and 17. In functional assays, sJAM-C was both chemotactic and chemokinetic for HMVECs and induced HMVEC tube formation on Matrigel in vitro. Neutralizing anti-JAM-C Abs inhibited RA synovial fluid-induced HMVEC chemotaxis and sJAM-C-induced HMVEC tube formation on Matrigel. sJAM-C also induced angiogenesis in vivo in the Matrigel plug and sponge granuloma models. Moreover, sJAM-C-mediated HMVEC chemotaxis was dependent on Src, p38, and PI3K. Our results show that JAM-C exists in soluble form and suggest that modulation of sJAM-C may provide a novel route for controlling pathological angiogenesis.