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Biomedical subjects

Alisa E Koch

Publications and source records attributed to Alisa E Koch.

At least 19 recordsLinked to original sources
PubMed2006

Porcine endothelial cells and iliac arteries transduced with AdenoIL-4 are intrinsically protected, through Akt activation, against immediate injury caused by human complement.

Vascular endothelial cells (ECs) can be injured in a variety of pathologic processes that involve activated complement. We reported previously that porcine ECs incubated with exogenous IL-4 or IL-13 are protected from cytotoxicity by human complement and also from apoptosis by TNF-alpha. The resistance to complement consists of an intrinsic mechanism that is lost a few days after cytokine removal. In our current study, we investigated whether transfer of the IL-4 gene into porcine ECs in vitro and into porcine vascular tissues in vivo would induce efficient and durable protection from human complement. We found that ECs transduced with adenoIL-4 or adenoIL-13 exhibited continuous production of the cytokine and prolonged protection from complement-mediated killing. IL-4 also protected ECs from activation: ECs incubated with IL-4 did not develop cell retraction and intercellular gaps upon stimulation with sublytic complement. The endothelium and subendothelium of pig iliac arteries that were transduced with the IL-4 gene were effectively protected from complement-dependent immediate injury after perfusion with human blood. However, after similar perfusion, the endothelium was immediately lost from arteries that were transduced with a control adenovirus. The protection was not due to up-regulation of the complement regulators decay accelerating factor, membrane cofactor protein, and CD59, or to reduced complement activation, but required the participation of Akt. Although our studies model protection in pig-to-primate xenotransplantation, our findings of IL-4 induction of Akt-mediated protection may be more broadly applicable to EC injury as manifested in ischemia-reperfusion, allotransplantation, and various vascular diseases.

Adenoviridae↗
PubMed2006

CXCL16-mediated cell recruitment to rheumatoid arthritis synovial tissue and murine lymph nodes is dependent upon the MAPK pathway.

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by profound mononuclear cell (MNC) recruitment into synovial tissue (ST), thought to be due in part to tumor necrosis factor alpha (TNFalpha), a therapeutic target for RA. Although chemokines may also be involved, the mechanisms remain unclear. We undertook this study to examine the participation of CXCL16, a novel chemokine, in recruitment of MNCs to RA ST in vivo and to determine the signal transduction pathways mediating this process. METHODS: Using a human RA ST-SCID mouse chimera, immunohistochemistry, enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction, flow cytometry, and in vitro chemotaxis assays, we defined the expression and function of CXCL16 and its receptor, CXCR6, as well as the signal transduction pathways utilized by them for MNC homing in vitro and in vivo. RESULTS: CXCL16 was markedly elevated in RA synovial fluid (SF) samples, being as high as 145 ng/ml. Intense macrophage and lining cell staining for CXCL16 in RA ST correlated with increased CXCL16 messenger RNA levels in RA ST compared with those in osteoarthritis and normal ST. By fluorescence-activated cell sorting analysis, one-half of RA SF monocytes and one-third of memory lymphocytes expressed CXCR6. In vivo recruitment of human MNCs to RA ST implanted in SCID mice occurred in response to intragraft injection of human CXCL16, a response similar to that induced by TNFalpha. Lipofection of MNCs with antisense oligodeoxynucleotides for ERK-1/2 resulted in a 50% decline in recruitment to engrafted RA ST and a 5-fold decline in recruitment to regional lymph nodes. Interestingly, RA ST fibroblasts did not produce CXCL16 in response to TNFalpha in vitro, suggesting that CXCL16 protein may function in large part independently of TNFalpha. CONCLUSION: Taken together, these results point to a unique role for CXCL16 as a premier MNC recruiter in RA and suggest additional therapeutic possibilities, targeting CXCL16, its receptor, or its signaling pathways.

Animals↗
PubMed2006

Identification of genes modulated in rheumatoid arthritis using complementary DNA microarray analysis of lymphoblastoid B cell lines from disease-discordant monozygotic twins.

OBJECTIVE: To identify disease-specific gene expression profiles in patients with rheumatoid arthritis (RA), using complementary DNA (cDNA) microarray analyses on lymphoblastoid B cell lines (LCLs) derived from RA-discordant monozygotic (MZ) twins. METHODS: The cDNA was prepared from LCLs derived from the peripheral blood of 11 pairs of RA-discordant MZ twins. The RA twin cDNA was labeled with cy5 fluorescent dye, and the cDNA of the healthy co-twin was labeled with cy3. To determine relative expression profiles, cDNA from each twin pair was combined and hybridized on 20,000-element microarray chips. Immunohistochemistry and real-time polymerase chain reaction were used to detect the expression of selected gene products in synovial tissue from patients with RA compared with patients with osteoarthritis and normal healthy controls. RESULTS: In RA twin LCLs compared with healthy co-twin LCLs, 1,163 transcripts were significantly differentially expressed. Of these, 747 were overexpressed and 416 were underexpressed. Gene ontology analysis revealed many genes known to play a role in apoptosis, angiogenesis, proteolysis, and signaling. The 3 most significantly overexpressed genes were laeverin (a novel enzyme with sequence homology to CD13), 11beta-hydroxysteroid dehydrogenase type 2 (a steroid pathway enzyme), and cysteine-rich, angiogenic inducer 61 (a known angiogenic factor). The products of these genes, heretofore uncharacterized in RA, were all abundantly expressed in RA synovial tissues. CONCLUSION: Microarray cDNA analysis of peripheral blood-derived LCLs from well-controlled patient populations is a useful tool to detect RA-relevant genes and could help in identifying novel therapeutic targets.

11-beta-Hydroxysteroid Dehydrogenase Type 2↗
PubMed2006

Regulation of interleukin-1beta-induced chemokine production and matrix metalloproteinase 2 activation by epigallocatechin-3-gallate in rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: To evaluate the efficacy of epigallocatechin-3-gallate (EGCG), a potent antiinflammatory molecule, in regulating interleukin-1beta (IL-1beta)-induced production of the chemokines RANTES (CCL5), monocyte chemoattractant protein 1 (MCP-1/CCL2), epithelial neutrophil-activating peptide 78 (ENA-78/CXCL5), growth-regulated oncogene alpha (GROalpha/CXCL1), and matrix metalloproteinase 2 (MMP-2) activity in rheumatoid arthritis (RA) synovial fibroblasts. METHODS: Fibroblasts obtained from RA synovium were grown, and conditioned medium was obtained. Cell viability was determined by MTT assay. RANTES, MCP-1, ENA-78, and GROalpha produced in culture supernatants were measured by enzyme-linked immunosorbent assay. MMP-2 activity was analyzed by gelatin zymography. Western blotting was used to study the phosphorylation of protein kinase C (PKC) isoforms and nuclear translocation of NF-kappaB. RESULTS: EGCG was nontoxic to RA synovial fibroblasts. Treatment with EGCG at 10 microM or 20 microM significantly inhibited IL-1beta-induced ENA-78, RANTES, and GROalpha, but not MCP-1 production in a concentration-dependent manner. EGCG at 50 microM caused a complete block of IL-1beta-induced production of RANTES, ENA-78, and GROalpha, and reduced production of MCP-1 by 48% (P < 0.05). Zymography showed that EGCG blocked constitutive, IL-1beta-induced, and chemokine-mediated MMP-2 activity. Evaluation of signaling events revealed that EGCG preferentially blocked the phosphorylation of PKCdelta and inhibited the activation and nuclear translocation of NF-kappaB in IL-1beta-treated RA synovial fibroblasts. CONCLUSION: These results suggest that EGCG may be of potential therapeutic value in inhibiting joint destruction in RA.

Arthritis, Rheumatoid↗
PubMed2006

Inhibition of angiogenesis by interleukin-4 gene therapy in rat adjuvant-induced arthritis.

OBJECTIVE: Interleukin-4 (IL-4) can modulate neovascularization. In this study, we used a gene therapy approach to investigate the role of IL-4 in angiogenesis in rat adjuvant-induced arthritis (AIA), a model for rheumatoid arthritis. METHODS: Rats received an adenovirus producing IL-4 (AxCAIL-4), a control virus without insert, or control vehicle (phosphate buffered saline) intraarticularly before arthritis onset. At peak onset of arthritis, rats were killed. Vascularization was determined in the synovial tissue, and correlations with inflammation were assessed. Ankle homogenates were used in angiogenesis assays in vitro and in vivo, and protein levels of cytokines and growth factors were assessed by enzyme-linked immunosorbent assay. Synovial tissue expression of alphav integrins was determined by immunohistochemistry. RESULTS: IL-4 induced a reduction in synovial tissue vessel density, which was paralleled by a decrease in inflammation. AxCAIL-4 joint homogenates significantly (P < 0.05) inhibited both endothelial cell (EC) migration and tube formation in vitro. Similarly, AxCAIL-4 inhibited capillary sprouting in the rat aortic ring assay, and vessel growth in the in vivo Matrigel plug assay. The angiostatic effect occurred despite high levels of vascular endothelial growth factor (VEGF), and was associated with down-regulation of the proangiogenic cytokines IL-18, CXCL16, and CXCL5 and up-regulation of the angiogenesis inhibitor endostatin. Of interest, AxCAIL-4 also resulted in decreased EC expression of the alphav and beta3 integrin chains. CONCLUSION: In rat AIA, IL-4 reduces synovial tissue vascularization via angiostatic effects, mediates inhibition of angiogenesis via an association with altered pro- and antiangiogenic cytokines, and may inhibit VEGF-mediated angiogenesis and exert its angiostatic role in part via alphavbeta3 integrin. This knowledge of the specific angiostatic effects of IL-4 may help optimize target-oriented treatment of inflammatory arthritis.

Adjuvants, Immunologic↗
PubMed2006

Role of aggrecanase 1 in Lyme arthritis.

OBJECTIVE: Arthritis is one of the hallmarks of late-stage Lyme disease. Previous studies have shown that infection with Borrelia burgdorferi, the causative agent of Lyme disease, results in degradation of proteoglycans and collagen in cartilage. B burgdorferi do not appear to produce any exported proteases capable of digesting proteoglycans and collagen, but instead, induce and activate host proteases, such as matrix metalloproteinases (MMPs), which results in cartilage degradation. The role of aggrecanases in Lyme arthritis has not yet been determined. We therefore sought to delineate the contribution of aggrecanases to joint destruction in Lyme arthritis. METHODS: We examined the expression patterns of aggrecanases 1 and 2 (ADAMTS 4 and 5, respectively) in B burgdorferi-infected primary human chondrocyte cell cultures, in synovial fluid samples from patients with active Lyme arthritis, and in the joints of mice by real-time quantitative reverse transcription-polymerase chain reaction and immunoblotting techniques. Bovine cartilage explants were used to determine the role of aggrecanases in B burgdorferi-induced cartilage degradation. RESULTS: ADAMTS-4, but not ADAMTS-5, was induced in human chondrocytes infected with B burgdorferi. The active forms of ADAMTS-4 were increased in synovial fluid samples from patients with active Lyme arthritis and were elevated in the joints of mice infected with B burgdorferi. Using cartilage explant models of Lyme arthritis, it appeared that the cleavage of aggrecan was predominantly mediated by "aggrecanases" rather than MMPs. CONCLUSION: The induction of ADAMTS-4 by B burgdorferi results in the cleavage of aggrecan, which may be an important first step that leads to permanent degradation of cartilage.

ADAM Proteins↗
PubMed2006

Macrophage migration inhibitory factor: a mediator of matrix metalloproteinase-2 production in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by destruction of bone and cartilage, which is mediated, in part, by synovial fibroblasts. Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes responsible for matrix degradation. Macrophage migration inhibitory factor (MIF) is a cytokine that induces the production of a large number of proinflammatory molecules and has an important role in the pathogenesis of RA by promoting inflammation and angiogenesis. In the present study, we determined the role of MIF in RA synovial fibroblast MMP production and the underlying signaling mechanisms. We found that MIF induces RA synovial fibroblast MMP-2 expression in a time-dependent and concentration-dependent manner. To elucidate the role of MIF in MMP-2 production, we produced zymosan-induced arthritis (ZIA) in MIF gene-deficient and wild-type mice. We found that MMP-2 protein levels were significantly decreased in MIF gene-deficient compared with wild-type mice joint homogenates. The expression of MMP-2 in ZIA was evaluated by immunohistochemistry (IHC). IHC revealed that MMP-2 is highly expressed in wild-type compared with MIF gene-deficient mice ZIA joints. Interestingly, synovial lining cells, endothelial cells, and sublining nonlymphoid mononuclear cells expressed MMP-2 in the ZIA synovium. Consistent with these results, in methylated BSA (mBSA) antigen-induced arthritis (AIA), a model of RA, enhanced MMP-2 expression was also observed in wild-type compared with MIF gene-deficient mice joints. To elucidate the signaling mechanisms in MIF-induced MMP-2 upregulation, RA synovial fibroblasts were stimulated with MIF in the presence of signaling inhibitors. We found that MIF-induced RA synovial fibroblast MMP-2 upregulation required the protein kinase C (PKC), c-jun N-terminal kinase (JNK), and Src signaling pathways. We studied the expression of MMP-2 in the presence of PKC isoform-specific inhibitors and found that the PKCdelta inhibitor rottlerin inhibits MIF-induced RA synovial fibroblast MMP-2 production. Consistent with these results, MIF induced phosphorylation of JNK, PKCdelta, and c-jun. These results indicate a potential novel role for MIF in tissue destruction in RA.

Animals↗
PubMed2006

Chemokines in rheumatic diseases.

Chemotactic cytokines, termed chemokines, mediate the ingress of leukocytes into the inflamed synovium. In this review, authors discuss the role of the most relevant chemokines and chemokine receptors involved in chronic inflammatory rheumatic diseases. Rheumatoid arthritis was chosen as a prototype to discuss these issues, as the majority of studies on the role of chemokines in inflammatory diseases were carried out in arthritis. However, other rheumatic diseases including systemic lupus erythematosus, systemic sclerosis, Sjögren's syndrome, mixed connective tissue disease, polymyositis/dermatomyositis, antiphospholipid syndrome and systemic vasculitides are also discussed in this context. Apart from discussing the pathogenic role of chemokines and their receptors, authors also review the regulation of chemokine production by other inflammatory mediators, as well as the important relevance of chemokines for antirheumatic therapies.

Animals↗
PubMed2005

Mcl-1 is essential for the survival of synovial fibroblasts in rheumatoid arthritis.

Mcl-1 is a Bcl-2-family, antiapoptotic molecule that is critical for the survival of T and B lymphocytes and macrophages; however, its role in nonhemopoietic cells remains to be fully elucidated. The current study focuses on the role of Mcl-1 in rheumatoid arthritis (RA). Mcl-1 was strongly expressed in the synovial lining and was increased in the sublining fibroblasts of patients with RA, compared with control synovial tissue. The expression of Mcl-1 in sublining fibroblasts correlated with the degree of inflammation and TNF-alpha, and IL-1beta treatment of cultured synovial fibroblasts resulted in the increased expression of Mcl-1 at the mRNA and protein levels. Mcl-1 was critical for the survival of RA synovial fibroblasts, because the forced reduction of Mcl-1 using a Mcl-1 antisense-expressing adenoviral vector induced apoptotic cell death, which was mediated through Bax, Bak, and Bim. These observations document a critical role for Mcl-1 in protecting against apoptosis in RA and suggest that Mc1-1 is a potential therapeutic target in this disease.

Arthritis, Rheumatoid↗
PubMed2005

Migration inhibitory factor up-regulates vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 via Src, PI3 kinase, and NFkappaB.

Cell adhesion molecules are critical in monocyte (MN) recruitment in immune-mediated and hematologic diseases. We investigated the novel role of recombinant human migration inhibitory factor (rhMIF) in up-regulating vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and their signaling pathways in human MNs. rhMIF-induced expression of VCAM-1 and ICAM-1 was significantly higher compared with nonstimulated MNs. rhMIF induced MN VCAM-1 and ICAM-1 expression in a concentration-dependent manner (P < .05). Antisense oligodeoxynucleotides (ODNs) and inhibitors of Src, PI3K, p38, and NFkappaB significantly reduced rhMIF-induced MN VCAM-1 and ICAM-1 expression (P < .05). However, Erk1/2 and Jak2 were not involved. Silencing RNA directed against MIF, and inhibitors of Src, PI3K, NFkappaB, anti-VCAM-1, and anti-ICAM-1 significantly inhibited rhMIF-induced adhesion of HL-60 cells to human dermal microvascular endothelial cells (HMVECs) or an endothelial cell line, HMEC-1, in cell adhesion assays, suggesting the functional significance of MIF-induced adhesion molecules (P < .05). rhMIF also activated MN phospho-Src, -Akt, and -NFkappaB in a time-dependent manner. rhMIF induced VCAM-1 and ICAM-1 up-regulation in 12 hours via Src, PI3K, and NFkappaB as shown by Western blotting and immunofluorescence. MIF and MIF-dependent signaling pathways may be a potential target for treating diseases characterized by up-regulation of cell adhesion molecules.

Cell Adhesion↗
PubMed2005

Accelerated development of arthritis in mice lacking endothelial selectins.

The selectins, along with very late antigen-4 and CD44, have been implicated in mediating leukocyte rolling interactions that lead to joint recruitment and inflammation during the pathogenesis of rheumatoid arthritis. Previously, we showed that P-selectin deficiency in mice resulted in accelerated onset of joint inflammation in the murine collagen-immunized arthritis model. Here, we report that mice deficient either in E-selectin or in E-selectin and P-selectin (E/P-selectin mutant) also exhibit accelerated development of arthritis compared with wild type mice in the CIA model, suggesting that these adhesion molecules perform overlapping functions in regulating joint disease. Analyses of cytokine and chemokine expression in joint tissue from E/P-selectin mutant mice before the onset of joint swelling revealed significantly higher joint levels of macrophage inflammatory protein-1alpha and IL-1beta compared to wild-type mice. IL-1beta remained significantly increased in E/P-selectin mutant joint tissue during the early and chronic phases of arthritis. Overall, these data illustrate the novel finding that E-selectin and P-selectin expression can significantly influence cytokine and chemokine production in joint tissue, and suggest that these adhesion molecules play important regulatory roles in the development of arthritis in E/P-selectin mutant mice.

Animals↗
PubMed2005

Local IL-13 gene transfer prior to immune-complex arthritis inhibits chondrocyte death and matrix-metalloproteinase-mediated cartilage matrix degradation despite enhanced joint inflammation.

During immune-complex-mediated arthritis (ICA), severe cartilage destruction is mediated by Fcgamma receptors (FcgammaRs) (mainly FcgammaRI), cytokines (e.g. IL-1), and enzymes (matrix metalloproteinases (MMPs)). IL-13, a T helper 2 (Th2) cytokine abundantly found in synovial fluid of patients with rheumatoid arthritis, has been shown to reduce joint inflammation and bone destruction during experimental arthritis. However, the effect on severe cartilage destruction has not been studied in detail. We have now investigated the role of IL-13 in chondrocyte death and MMP-mediated cartilage damage during ICA. IL-13 was locally overexpressed in knee joints after injection of an adenovirus encoding IL-13 (AxCAhIL-13), 1 day before the onset of arthritis; injection of AxCANI (an empty adenoviral construct) was used as a control. IL-13 significantly increased the amount of inflammatory cells in the synovial lining and the joint cavity, by 30% to 60% at day 3 after the onset of ICA. Despite the enhanced inflammatory response, chondrocyte death was diminished by two-thirds at days 3 and 7. The mRNA level of FcgammaRI, a receptor shown to be crucial in the induction of chondrocyte death, was significantly down-regulated in synovium. Furthermore, MMP-mediated cartilage damage, measured as neoepitope (VDIPEN) expression using immunolocalization, was halved. In contrast, mRNA levels of MMP-3, -9, -12, and -13 were significantly higher and IL-1 protein, which induces production of latent MMPs, was increased fivefold by IL-13. This study demonstrates that IL-13 overexpression during ICA diminished both chondrocyte death and MMP-mediated VDIPEN expression, even though joint inflammation was enhanced.

Adenoviridae↗
PubMed2005

Amelioration of rat adjuvant-induced arthritis by Met-RANTES.

OBJECTIVE: CC chemokines and their receptors play a fundamental role in trafficking and activation of leukocytes at sites of inflammation, contributing to joint damage in rheumatoid arthritis. Met-RANTES, an amino-terminal-modified methionylated form of RANTES (CCL5), antagonizes the binding of the chemokines RANTES and macrophage inflammatory protein 1alpha (MIP-1alpha; CCL3) to their receptors CCR1 and CCR5, respectively. The aim of this study was to investigate whether Met-RANTES could ameliorate adjuvant-induced arthritis (AIA) in the rat. METHODS: Using immunohistochemistry, enzyme-linked immunosorbent assay, real-time reverse transcription-polymerase chain reaction, Western blot analysis, adoptive transfer, and chemotaxis, we defined joint inflammation, bony destruction, neutrophil and macrophage migration, Met-RANTES binding affinity to rat receptors, proinflammatory cytokine and bone marker levels, CCR1 and CCR5 expression and activation, and macrophage homing into joints with AIA. RESULTS: Administration of Met-RANTES as a preventative reduced the severity of joint inflammation. Administration of Met-RANTES to ankles with AIA showed decreases in inflammation, radiographic soft tissue swelling, and bone erosion. Met-RANTES significantly reduced the number of neutrophils and macrophages at the peak of arthritis compared with saline-injected controls. Competitive chemotaxis in peripheral blood mononuclear cells demonstrated that Met-RANTES inhibited MIP-1alpha and MIP-1beta at 50% inhibition concentrations of 5 nM and 2 nM, respectively. Furthermore, levels of tumor necrosis factor alpha, interleukin-1beta, macrophage colony-stimulating factor, and RANKL were decreased in joints with AIA in the Met-RANTES group compared with the control group. Interestingly, the expression and activation of CCR1 and CCR5 in the joint were down-regulated in the Met-RANTES group compared with the control group. Functionally, Met-RANTES administration decreased adoptively transferred peritoneal macrophage homing into the joint. CONCLUSION: The data suggest that the targeting of Th1-associated chemokine receptors reduce joint inflammation, bone destruction, and cell recruitment into joints with AIA.

Animals↗
PubMed2005

Chemokine receptor expression in rat adjuvant-induced arthritis.

OBJECTIVE: Chemokine receptors mediate leukocyte migration into inflamed rheumatoid arthritis (RA) synovial tissue (ST). Knowledge of their distribution is crucial for understanding the evolution of the inflammatory process. In this study, we used rat adjuvant-induced arthritis (AIA), a model for RA, to define the temporospatial expression of chemokine receptors. METHODS: ST from rats with AIA was immunostained, the percentage of cells expressing each receptor was determined, and findings were correlated with levels of inflammation. Chemokine receptor expression was evaluated on rat macrophages in vitro. RESULTS: CCR1, a receptor for macrophage inflammatory protein 1alpha (MIP-1alpha)/CCL3 and RANTES/CCL5, exhibited high constitutive expression on macrophages in AIA. CCR5, binding MIP-1alpha/CCL3 and RANTES/CCL5, was up-regulated on ST macrophages during the course of AIA, correlating with macrophage expression of CCR2, a receptor for monocyte chemoattractant protein 1/CCL2. Endothelial cell (EC) CCR2 was down-regulated as arthritis progressed, inversely correlating with inflammation. CCR3, another RANTES/CCL5 receptor, was constitutively high on macrophages in vivo and in vitro, with down-regulation during AIA. CXCR4, a receptor for stromal cell-derived factor 1/CXCL12), was prominently up-regulated on ECs, preceding the peak of inflammation. CONCLUSION: These findings show that 1) constitutive expression of CCR1 on macrophages remains high during AIA; 2) CCR2 and CCR3 may play a role in initial recruitment of leukocytes to ST in AIA; 3) macrophage expression of CCR2 and CCR5 may be important for sustaining inflammatory changes; and 4) EC CXCR4 may be a harbinger of inflammatory changes. Our results may help guide chemokine receptor blockade-targeting treatment strategies in inflammatory arthritis.

Animals↗
PubMed2005

Endothelial cells in inflammation and angiogenesis.

Endothelial cells are involved in leukocyte extravasation underlying inflammation. A number of adhesion molecules play a role in leukocyte-endothelial interactions. New vessel formation, termed angiogenesis, is also crucial for leukocyte extravasation. The outcome of neovascularization is highly dependent on the balance or imbalance between angiogenic mediators and inhibitors. There have been several attempts to therapeutically interfere with the cellular and molecular mechanisms, such as leukocyte-endothelial cell adhesion and angiogenesis. Most studies have been performed using animal models of various types of inflammation, such as arthritis. In addition, a very limited number of human clinical trials gave promising results. In this review, authors summarize the most relevant information on adhesion molecules, as well as angiogenic and angiostatic agents. In addition, further perspectives of anti-adhesive and anti-angiogenic therapy are also discussed. Specific targeting of pathological endothelial function including adhesion and angiogenesis, may be useful for the future management of various inflammatory diseases.

Animals↗
PubMed2004

Mechanism by which H-2g, a glucose analog of blood group H antigen, mediates angiogenesis.

The 4A11 antigen is a unique cytokine-inducible antigen up-regulated on rheumatoid arthritis (RA) synovial endothelial cells (ECs) compared with normal ECs. Previously, we showed that in soluble form, this antigen, Lewis(y)-6/H-5-2 (Le(y)/H) or its glucose analog, 2-fucosyl lactose (H-2g), induced the expression of EC intercellular adhesion molecule-1 (ICAM-1) and leukocyte-endothelial adhesion through the Janus kinase 2 (JAK2)-signal transducer and activator of transcription 3 (STAT3) pathway. Currently, we show that H-2g induces release of EC angiogenic basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF), an effect inhibited by decoy nuclear factor kappaB (NFkappaB) oligodeoxynucleotide (ODN). JAK2 and phosphoinositide-3 kinase (PI3K) are 2 upstream kinases of NFkappaB activated by H-2g, as confirmed by an inhibitor of kappa B kinase (IKKbeta) assay. In vitro, H-2g induces vascular sprouting in the rat aortic ring model, whereas blockade of JAK2, PI3K, or NFkappaB inhibits sprouting. Likewise, in the in vivo mouse Matrigel plug angiogenesis assay, chemical inhibitors and antisense or decoy ODNs of JAK2, PI3K, or NFkappaB decrease angiogenesis, confirming the importance of these pathways in H-2g-induced EC signaling. The critical role of Le(y)/H involvement in angiogenesis and its signaling pathways may provide new targets for therapy of diseases characterized by pathologic neovascularization.

ABO Blood-Group System↗
PubMed2004

Retinoblastoma suppression of matrix metalloproteinase 1, but not interleukin-6, through a p38-dependent pathway in rheumatoid arthritis synovial fibroblasts.

OBJECTIVE: Rheumatoid arthritis (RA) is characterized by increased synovial lining cellularity, inflammation, and destruction of cartilage and bone. During the pathogenesis of RA, synovial fibroblasts reenter the cell cycle and multiply in number. RA synovial fibroblasts express high levels of the MAP kinase p38, which may contribute to the production of interleukin-6 (IL-6) and matrix metalloproteinases (MMPs). IL-6 and MMP-1 promote inflammation and joint destruction, respectively. Taken together, these findings indicate that in RA the enhanced cell cycle activity and production of IL-6 and MMP-1 may be linked. Therefore, we sought to determine if the tumor suppressor gene product retinoblastoma (Rb), a negative regulator of cell cycle activity, inhibits IL-6, MMP-1, and p38 in RA synovial fibroblasts. METHODS: RA and non-RA synovial fibroblasts were examined by enzyme-linked immunosorbent assay (ELISA) for the relative expression of inactive hyperphosphorylated Rb (inactive Rb/total Rb). Ectopic Rb expression was mediated by infection with a replication-defective adenovirus that expresses Rb (Ad-Rb). A control replication-defective adenovirus that expresses beta-galactosidase (Ad-beta-gal) was used. Cell cycle activity was determined by flow cytometry. IL-6 and MMP-1 expression was examined by real-time polymerase chain reaction and ELISA. Expression and activation of p38 were determined by kinase assays and ELISA. The activity of p38 was enhanced by infecting RA synovial fibroblasts with a replication-defective adenovirus that expresses a constitutively active form of MAPK kinase 3 (Ad-CA-MKK3), an upstream activator of p38. RESULTS: Quiescent RA, compared with non-RA synovial fibroblasts, displayed a 200% (P < 0.02) increase in the inactive Rb isoform. Proliferating RA synovial fibroblasts exhibited a 60% (P < 0.12) increase in the inactive Rb isoform compared with non-RA synovial fibroblasts. Increased levels of the active Rb isoform inhibited cell cycle progression and suppressed IL-6 and MMP-1 secretion in RA synovial fibroblasts, although the steady-state levels of IL-6 and MMP-1 messenger RNA remained unchanged. However, Rb overexpression had no effect on spontaneous or IL-1beta-induced production of IL-6 or MMP-1 in non-RA synovial fibroblasts. Ectopic Rb expression reduced the activity of p38. Ad-CA-MKK3 infection in RA synovial fibroblasts increased p38 phosphorylation, and MMP-1 but not IL-6 secretion. In contrast, Rb overexpression inhibited Ad-CA-MKK3-mediated phosphorylation of p38 and subsequent increase in MMP-1. CONCLUSION: Rb-mediated suppression of IL-6 and MMP-1 occurs at a posttranscriptional level. However, Ad-Rb reduction of MMP-1 but not IL-6 requires inhibition of the p38 pathway. These results suggest that Rb negatively regulates p38 activation, leading to decreased MMP-1 secretion in RA synovial fibroblasts.

Adenoviridae↗