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Biomedical subjects

Alisa E Koch

Publications and source records attributed to Alisa E Koch.

36 records · Page 2Linked to original sources

Therapeutic inhibition of leukocyte recruitment in inflammatory diseases.

The ingress of leukocytes into sites of inflammation is crucial for the pathogenesis of arthritis and other inflammatory conditions. Chemokines, their receptors and cellular adhesion molecules (CAMs) are involved in this process. Here, the roles of the most relevant chemokines, chemokine receptors and CAMs are briefly reviewed. There have been several attempts to target chemokine- and CAM-mediated pathways in preclinical studies using animal models of arthritis, and in a limited number of human studies. In this review, the most recent advances in anti-chemokine and anti-adhesion therapeutic strategies are summarized.

Animals↗

Vascular endothelium and immune responses: implications for inflammation and angiogenesis.

ECs are involved in several mechanisms during the immune response, particularly in inflammation. These cells are able to produce vasodilatory mediators and several factors lead to increased vascular permeability. ECs play a central role in leukocyte extravasation, a key feature of inflammation. Several adhesion molecules, termed integrins, selectins, immunoglobulins, and others, act in concert and regulate the sequence of distinct steps. Leukocyte-EC adhesion is regulated by the interactions of receptor-ligand CAM pairs, as well as by soluble mediators, such as proinflammatory cytokines. ECs are active participants in angiogenesis. The outcome of neovascularization is highly dependent on the balance or imbalance between angiogenic mediators and inhibitors. Angiogenic mediators form a complex interactive network that regulates the perpetuation of angiogenesis. Naturally-produced or administered angiostatic agents downregulate the effects of angiogenic factors. There have been several attempts to therapeutically interfere with the cellular and molecular mechanisms described above. Most studies were performed using animal models of various types of inflammation. A limited number of human clinical trials, such as the one using anti-ICAM-1 antibody in RA, had promising results. Specific targeting of pathologic endothelial function may be useful for the future management of various inflammatory diseases.

Animals↗

Migration inhibitory factor mediates angiogenesis via mitogen-activated protein kinase and phosphatidylinositol kinase.

In this study, we investigated the effects of migration inhibitory factor (rhMIF) on angiogenesis-related signaling cascades and apoptosis in human endothelial cells (ECs). We show that in vitro rhMIF induces migration and tube formation in Matrigel of human dermal microvascular endothelial cells (HMVECs), with potency comparable to that of basic fibroblast growth factor. In vivo, rhMIF induces angiogenesis in Matrigel plugs and in the corneal bioassay. Using panels of relatively specific kinase inhibitors, antisense oligonucleotides, and dominant-negative mutants, we show that mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) are critical for MIF-dependent HMVEC migration, whereas Src and p38 kinases are nonessential. Moreover, we demonstrate that rhMIF induces time-dependent increases in phosphorylation levels of MEK1/2, Erk1/2, and Elk-1, as well as PI3K, and its effector kinase, Akt, in HMVECs. Studies with dominant-negative mutants and antisense oligonucleotides corroborate these effects in HMVECs. Furthermore, we demonstrate that rhMIF-induced angiogenesis in the rat cornea in vivo and in the ex vivo endothelial cell morphogenesis assay is also MAPK- and PI3K-dependent. Our findings support a role for MIF as an angiogenic factor and provide a rationale for the use of MIF as a therapeutic inducer of neovascularization in the development of collateral circulation in coronary artery disease.

Angiogenesis Inducing Agents↗

A novel function for a glucose analog of blood group H antigen as a mediator of leukocyte-endothelial adhesion via intracellular adhesion molecule 1.

The 4A11 antigen is a unique cytokine-inducible antigen up-regulated on rheumatoid arthritis synovial endothelium compared with normal endothelium. In soluble form, this antigen, Lewisy-6/H-5-2 (Ley/H), or its glucose analog, 2-fucosyllactose (H-2g), mediates angiogenesis. The Ley/H antigen is structurally related to the soluble E-selectin ligand, sialyl Lewisx, and is selectively expressed in skin, lymphoid organs, thymus, and synovium, suggesting that it may be important in leukocyte homing or adhesion. In the present study, we used H-2g as a functional substitute to demonstrate a novel property for Ley/H antigen in inducing leukocyte-endothelial adhesion. H-2g significantly enhanced the expression of human dermal microvascular endothelial cells (HMVECs) intercellular adhesion molecule-1 (ICAM-1), but not vascular cell adhesion molecule-1, E-selectin, and P-selectin. Immunoprecipitation and Western blotting showed glycolipids Ley-6, H-5-2, or the glucose analog H-2g quickly activated human microvascular endothelial cell line-1 (HMEC-1) Janus kinase 2 (JAK2) and that the JAK2 inhibitor, AG-490, completely inhibited HMVEC ICAM-1 expression and HL-60 adhesion to HMEC-1s. Use of a JAK/signal transducer and activator of transcription (STAT) profiling system confirmed that H-2g selectively activated STAT3 but not STAT1 and STAT2. AG-490 inhibited H-2g-induced Erk1/2 and PI3K-Akt activation, suggesting that JAK2 is upstream of the Erk1/2 and PI3K-Akt pathways. Furthermore, the JAK2 inhibitor AG-490, the Erk1/2 inhibitor PD98059, or the phosphatidylinositol 3-kinase inhibitor LY294002 or antisense oligodeoxynucleotides directed against JAK2, Erk1/2, or phosphatidylinositol 3-kinase blocked H-2g-induced HMVEC ICAM-1 expression and HL-60 adhesion to HMEC-1s. Hence, H-2g signals through JAK2 and its downstream signal transducers STAT3, Erk1/2, and phosphatidylinositol 3-kinase result in ICAM-1 expression and cell adhesion. Potential treatment strategies through the inhibition of JAK-dependent pathways to target H-2g signals may provide a useful approach in inflammation-driven diseases like rheumatoid arthritis.

ABO Blood-Group System↗

IL-6 and matrix metalloproteinase-1 are regulated by the cyclin-dependent kinase inhibitor p21 in synovial fibroblasts.

During the pathogenesis of rheumatoid arthritis (RA), the synovial fibroblasts increase in number and produce proinflammatory cytokines and matrix metalloproteinases (MMPs) that function to promote inflammation and joint destruction. Recent investigations have suggested that cell cycle activity and inflammation may be linked. However, little is known about the mechanisms responsible for the coordinate regulation of proliferation and the expression of proinflammatory molecules in RA synovial fibroblasts. Here, we demonstrate a 50 +/- 10% decrease in the expression of p21, a cell cycle inhibitor, in the synovial fibroblast population from RA compared with osteoarthritis (OA) synovial tissue. Moreover, p21 positivity in the synovial fibroblasts inversely correlates with medium synovial lining thickness (r = -0.76; p < 0.02). The expression of p21 is also reduced in isolated RA synovial fibroblasts compared with OA synovial fibroblasts. Adenovirus-mediated delivery of p21 (Ad-p21) arrests both RA and OA synovial fibroblasts in the G(0)/G(1) phase of the cell cycle without inducing cytotoxicity. However, the spontaneous production of IL-6 and MMP-1 is suppressed only in the Ad-p21-infected RA synovial fibroblasts, indicating a novel role for p21 in RA. Analyses of p21-deficient mouse synovial fibroblasts reveal a 100-fold increase in IL-6 protein and enhance IL-6 and MMP-3 mRNA. Restoration of p21, but not overexpression of Rb, which also induces G(0)/G(1) cell cycle arrest, decreases IL-6 synthesis in p21-null synovial fibroblasts. Furthermore, in RA synovial fibroblasts the ectopic expression of p21 reduces activation of the AP-1 transcription factor. Additionally, p21-null synovial fibroblasts display enhanced activation of AP-1 compared with wild-type synovial fibroblasts. These data suggest that alterations in p21 expression may activate AP-1 leading to enhanced proinflammatory cytokine and MMP production and development of autoimmune disease.

Adenoviridae↗

Src and phosphatidylinositol 3-kinase mediate soluble E-selectin-induced angiogenesis.

Angiogenesis plays an important role in a variety of pathophysiologic processes, including tumor growth and rheumatoid arthritis. We have previously shown that soluble E-selectin (sE-selectin) is an important angiogenic mediator. However, the mechanism by which sE-selectin mediates angiogenesis is still unknown. In this study, we show that sE-selectin is a potent mediator of human dermal microvascular endothelial cell (HMVEC) chemotaxis, which is predominantly mediated through the Src and the phosphatidylinositiol 3-kinase (PI3K) pathways. Further, sE-selectin induced a 2.2-fold increase in HMVEC tube formation in the Matrigel in vitro assay. HMVECs pretreated with the Src inhibitor (PP2) and the PI3K inhibitor (LY294002) or transfected with Src antisense oligonucleotides or Akt dominant-negative mutants significantly inhibited sE-selectin-mediated HMVEC tube formation. In contrast, HMVECs transfected with an extracellular signal-related kinase 1/2 (ERK1/2) mutant or pretreated with the mitogen-activated protein kinase (MAPK) inhibitor PD98059 failed to show sE-selectin-mediated HMVEC tube formation. Similarly, in the Matrigel-plug in vivo assay, sE-selectin induced a 2.2-fold increase in blood vessel formation, which was significantly inhibited by PP2 and LY294002 but not by PD98059. sE-selectin induced a marked increase in Src, ERK1/2, and PI3K phosphorylation. PI3K and ERK1/2 phosphorylation was significantly inhibited by PP2, thereby suggesting that both of these pathways may be activated via Src kinase. Even though the ERK1/2 pathway was activated by sE-selectin in HMVECs, it seems not to be essential for sE-selectin-mediated angiogenesis. Taken together, our data clearly show that sE-selectin-induced angiogenesis is predominantly mediated through the Src-PI3K pathway.

Cells, Cultured↗

Chemokine receptor expression and in vivo signaling pathways in the joints of rats with adjuvant-induced arthritis.

OBJECTIVE: This study was undertaken to characterize the role of CC chemokines and their receptors in rat adjuvant-induced arthritis (AIA), a model for rheumatoid arthritis (RA). Furthermore, we investigated the signaling pathways associated with CC receptors as well as the cell type distribution of the receptors. METHODS: Using TaqMan real-time reverse transcription-polymerase chain reaction, Western blot analysis, and immunohistochemistry, we defined chemokine and chemokine receptor messenger RNA (mRNA) expression, CC chemokine receptor (CCR) protein activation during the disease course, CCR-associated signaling pathways, and immunopositive CCR5, phosphorylated signal transducer and activator of transcription 1 (p-STAT-1), and p-STAT-3 cells in rat AIA versus control joints. RESULTS: We showed significant up-regulation of CCR1, CCR2, CCR5, and macrophage inflammatory protein 1beta/CCL4 mRNA in AIA on post-adjuvant injection day 18, coincident with peak inflammation. Additionally, increases in tyrosine phosphorylation of CCR1 (days 14, 18, 21, and 24), CCR2 (days 14 and 18), and CCR5 (days 14, 18, and 21) were detected in AIA rats compared with control (nonarthritic) rats. JAK-1, STAT-1, and STAT-3 were associated with CCR1 and were highly tyrosine phosphorylated on days 14 and 18. Moreover, CCR2 was associated with JAK-2, STAT-1, and STAT-3 on day 18. The association of STAT-1 and STAT-3 with CCR5 on days 18 and 21 correlated with JAK-1 phosphorylation and binding on day 18. However, the activation of JNK was not associated with CCR5 activation in rat AIA. Immunohistochemical analysis demonstrated that the expression of CCR5, p-STAT-1, and p-STAT-3 was detected on synovial lining cells, macrophages, and endothelial cells in arthritic rat ankles on post-adjuvant injection day 18. While the majority of the CCR5 and p-STAT-1 immunostaining was on synovial lining cells and macrophages, p-STAT-3 was predominantly expressed on endothelial cells. CONCLUSION: CCR1, CCR2, and CCR5 mRNA expression and tyrosine phosphorylation increased with peak inflammation in the AIA model. CCR1, CCR2, and CCR5 tyrosine phosphorylation are associated with the JAK/STAT-1/STAT-3 pathway at different stages of rat AIA, as well as with macrophage and endothelial cell infiltration. However, their signaling activation overlaps with peak inflammation. Up-regulation and activation of CCRs may play a role in macrophage and endothelial cell infiltration in rat AIA joints in addition to activating the associated signaling pathways. The downstream intermediate signaling proteins associated with CC receptors may be used as potential tools to control inflammation in RA.

Animals↗

The role of COX-2 in angiogenesis and rheumatoid arthritis.

Recent evidence suggests that cyclooxygenase (COX)-2 is a mediator of angiogenesis, and COX-2 activity is known to be upregulated in the rheumatoid arthritis (RA) synovium. We examined whether mediation of angiogenesis by COX-2 was occuring in cells of the RA synovium and in microvascular endothelial cells (ECs) that are similar to those found in the RA synovium. We demonstrate that rofecoxib, a selective COX-2 inhibitor, acts directly on human dermal microvascular ECs (HMVECs) to inhibit their chemotactic and tube forming ability. Likewise, pretreatment of HMVECs with rofecoxib significantly inhibited their ability to form tubes induced by conditioned media (CM) of activated RA synovial fibroblasts. When RA synovial fibroblasts were pretreated with rofecoxib for 16 h and then stimulated with interleukin (IL)-1beta, their CM induced significantly less HMVEC tube formation when compared with CM from vehicle-treated RA synovial fibroblasts. ELISAs performed on activated RA fibroblast CM for known proangiogenic factors demonstrated a significant reduction in bFGF, in addition to the expected decrease in PGE(2). Our studies suggest that COX-2-induced angiogenic activity is an active mechanism within diseased synovium and may provide an additional rationale for the use of COX-2 inhibitors in RA.

Arthritis, Rheumatoid↗

Chemokines and chemokine receptors in rheumatoid arthritis.

Chemokines are chemotactic cytokines involved in a number of pathological processes, including inflammatory conditions. Chemokines play a role in the pathogenesis of various inflammatory diseases. Based on a burgeoning body of literature, RA was chosen as a prototype to discuss this issue. In this review, the authors give a detailed introduction to the classification and function of chemokines and their receptors. This is followed by a discussion of the role of chemokines and chemokine receptors in RA. Chemokines interact with other inflammatory mediators, such as cytokines. Thus, the regulation of chemokine production and the place of chemokines in the network of inflammatory mediators present in the rheumatoid synovium are also reviewed. Finally, potential strategies using anti-chemokine or anti-chemokine receptor biologicals in anti-rheumatic therapy are discussed.

Animals↗

Role of macrophage inflammatory protein-3alpha and its ligand CCR6 in rheumatoid arthritis.

We examined the expression and participation of CCR6 and its ligand MIP-3alpha in rheumatoid arthritis (RA) by ELISA, RT-PCR, real-time PCR (TaqMan) analysis, monocyte chemotaxis, and two- and four-color flow cytometry. We found that RA synovial fluid (SF) contained significantly more MIP-3alpha than osteoarthritis (OA), indicating a potential role for MIP-3alpha in RA. IL-1beta, IL-18, and TNF-alpha stimulated RA fibroblast MIP-3alpha production at 48 hours of incubation in vitro. By TaqMan analysis, there were more CCR6 mRNA transcripts in RA synovial tissue (ST) than in OA or normal (NL) ST, and elevated MIP-3alpha mRNA expression in RA compared with NL ST. By FACS analysis, there were significantly elevated percentages of CD3+/CD4+/CD45RO+/CCR6+ memory lymphocytes found in RA peripheral blood (PB) compared with NL PB or RA SF. We also found that MIP-3alpha induced monocyte chemotactic activity at 1.25 pM, consistent with concentrations of MIP-3alpha found in RA SF. Furthermore, MIP-3alpha accounted for 40% of RA SF chemotactic activity for monocytes in modified Boyden chamber assays. We confirmed that MIP-3alpha may be binding a G-coupled protein receptor because in vitro monocyte chemotaxis was inhibited by preincubation of monocytes with pertussis toxin. RA patient clinical data revealed that CD3+ lymphocyte/CCR6 expression inversely correlated with the age of the patient, indicating that CCR6 expression may be important in the development of RA at a younger age. Overall, these studies indicate that MIP-3alpha and CCR6 may function to recruit monocytes and memory lymphocytes from the RA PB to the RA joint. These results further indicate that expression of CCR6, the receptor for MIP-3alpha, can be correlated with RA development.

Adult↗

Sensitization of IFN-gamma Jak-STAT signaling during macrophage activation.

A general paradigm in signal transduction is ligand-induced feedback inhibition and the desensitization of signaling. We found that subthreshold concentrations of interferon-gamma (IFN-gamma), which did not activate macrophages, increased their sensitivity to subsequent IFN-gamma stimulation; this resulted in increased signal transducer and activator of transcription 1 (STAT1) activation and increased IFN-gamma#150;dependent gene activation. Sensitization of IFN-gamma signaling was mediated by the induction of STAT1 expression by low doses of IFN-gamma that did not effectively induce feedback inhibition. IFN-gamma signaling was sensitized in vivo after IFN-gamma injection, and STAT1 expression was increased after injection of lipopolysaccharide and in rheumatoid arthritis synovial cells. These results identify a mechanism that sensitizes macrophages to low concentrations of IFN-gamma and regulates IFN-gamma responses in acute and chronic inflammation.

Animals↗

Signal transduction pathways involved in rheumatoid arthritis synovial fibroblast interleukin-18-induced vascular cell adhesion molecule-1 expression.

Vascular cell adhesion molecule (VCAM)-1 has been implicated in interactions between leukocytes and connective tissue, including rheumatoid arthritis (RA) synovial tissue fibroblasts. Such interactions within the synovium contribute to RA inflammation. Using phosphoinositide 3-kinase (PI3-kinase) inhibitor LY294002 and Src inhibitor PP2, we show that interleukin (IL)-18-induced ERK1/2 activation is Src kinase-dependent. Antisense (AS) c-Src oligonucleotide (ODN) treatment reduced IL-18-induced ERK1/2 expression by 32% compared with control, suggesting an upstream role of Src in ERK1/2 activation. AS c-Src ODN treatment also inhibited Akt expression by 74% compared with sense control. PI3-kinase inhibitor LY294002 or AS PI3-kinase ODN inhibited Akt expression. AS c-Src ODN inhibited Akt phosphorylation, confirming Src is upstream of PI3-kinase in IL-18-induced RA synovial fibroblast signaling. IL-18 induced a time-dependent activation of c-Src, Ras, and Raf-1, suggesting this signaling cascade plays a role in ERK activation. IL-18 directly activated Src kinase by more than 4-fold over basal levels by enzymatic assay. Electrophoretic mobility shift assay showed that activator protein-1 (AP-1) is activated by IL-18 through ERK and Src but not through PI3-kinase. In an alternate pathway, inhibition of IL-1 receptor-associated kinase-1 (IRAK) with AS ODN to IRAK reduced IL-18-induced expression of nuclear factor kappaB (NFkappaB). Finally, IL-18-induced cell surface VCAM-1 expression was inhibited by treatment with AS ODNs to c-Src, IRAK, PI3-kinase, and ERK1/2 by 57, 43, 41, and 32% compared with control sense ODN treatment, respectively. These data support a role for IL-18 activation of three distinct pathways during RA synovial fibroblast stimulation: two Src-dependent pathways and the IRAK/NFkappaB pathway. Targeting VCAM-1 signaling mechanisms may represent therapeutic approaches to inflammatory and angiogenic diseases characterized by adhesion molecule up-regulation.

Arthritis, Rheumatoid↗

Interleukin-13 gene therapy reduces inflammation, vascularization, and bony destruction in rat adjuvant-induced arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial pannus formation, leukocyte infiltration, and angiogenesis. Adenoviral production of interleukin-13 (IL-13) reduces levels of proinflammatory mediators in an explant model of RA synovial tissue in vitro. To assess this approach in an animal model of arthritis, we compared intra-articular injections of an adenovirus producing rat IL-13 (AxCArIL-13), a control virus, and rat ankles receiving phosphate-buffered saline (PBS) in rat adjuvant-induced arthritis (AIA). We demonstrate that IL-13 levels are normally low in ankles throughout the course of rat AIA. We show that administration of AxCArIL-13 before arthritis onset significantly reduces ankle circumference, paw volume, bony destruction, the number of polymorphonuclear cells (PMNs), the quantity of blood vessels, and levels of monocyte chemoattractant protein (MCP)-1 in ankles. When administered as a treatment to inflamed ankles, AxCArIL-13 decreases articular index scores, paw volumes, bony destruction, vascularization, tumor necrosis factor-alpha (TNF-alpha) levels, and the quantity of monocytes, lymphocytes, and PMNs. Thus, increasing IL-13 levels significantly ameliorates the course of rat AIA, suggesting that similar strategies for the treatment of human RA are worthy of further study.

Adenoviridae↗

Differential expression of the angiogenic Tie receptor family in arthritic and normal synovial tissue.

Angiopoietins (Ang) are vascular endothelial cell-specific growth factors that play important roles principally during the later stages of angiogenesis. We have compared the distribution of the receptor tyrosine kinase (Tie) and the Ang ligands in synovial tissues from normal subjects and those with rheumatoid arthritis (RA) and osteoarthritis (OA). Immunohistochemical analysis was used to determine the expression of Ang-1, Ang-2, Tie1 and Tie2 in synovial tissue of normal subjects and those with RA and OA. Ang-1, Ang-2, Tie1 and Tie2 mRNA and protein expression were quantified in synovial tissues and RA synovial tissue fibroblasts with real-time reverse transcription polymerase chain reaction and western blot analysis. In RA, Ang-1 positive immunostaining on lining cells, macrophages and endothelial cells was significantly higher than in OA and normal synovial tissue. The expression pattern of Ang-2 in synovial tissue was similar in RA and OA, whereas the Ang-2 expression was low in normal tissue. Synovial tissue from subjects with RA and OA showed a significant upregulation of Tie1 on lining cells, macrophages and endothelial cells compared to that from normal subjects. Tie2 was significantly upregulated in the RA and OA synovial tissue lining cells, macrophages and smooth muscle cells compared to normal synovial tissue. Generally Ang-1, Ang-2, Tie1 and Tie2 mRNA levels were higher in RA synovial tissue compared to normal and OA synovial tissues, and RA synovial tissue fibroblasts. Western blot analysis also demonstrated greater Tie1 and Tie2 protein expression in RA and OA synovial tissue compared to RA synovial tissue fibroblasts. In conclusion, the dominance of Ang-1 mRNA and protein expression over Ang-2 is in agreement with an active neovascularization in RA synovial tissue.

Angiopoietin-1↗

The effect of sulfasalazine on rheumatoid arthritic synovial tissue chemokine production.

Rheumatoid arthritis (RA) is an aggressive inflammatory disease in which chemokines are thought to recruit leukocytes and induce angiogenesis. The aim of this study was to investigate the effects of sulfasalazine (SASP) and its metabolites, sulfapyridine (SP), and 5-aminosalicylic acid (5ASA) on chemokine production by RA synovial tissue explants and interleukin (IL)-1beta-stimulated RA synovial tissue fibroblasts using enzyme-linked immunosorbent assays and flow cytometry. Synovial tissue explants from RA patients secreted a decreased amount of the chemokines IL-8 and growth-related gene product alpha (GROalpha) when treated with SASP over a broad range of concentrations based on the typical clinical dosage of 2 g/day. SP had a significant effect in that it decreased RA synovial tissue explant secretion of IL-8 (22%), GROalpha (55%), and monocyte chemotactic protein-1 (MCP-1) (42%) (P < 0.05). 5ASA had no effect on RA synovial tissue explant production of IL-8 and MCP-1, while increasing GROalpha production. In IL-1beta-stimulated RA synovial tissue fibroblasts, SASP significantly increased chemokine secretion, while SP significantly decreased IL-8 (24%) and GROalpha (21%) secretion (P < 0.05). Flow cytometry showed that the number of IL-8 expressing RA synovial tissue fibroblasts did not significantly change following SP treatment. These data suggest that SASP may function to reduce inflammation in RA through the effects of its metabolite SP to reduce the secretion of the inflammatory chemokines IL-8, GROalpha, and MCP-1.

Adult↗

Modifications in adenoviral coat fiber proteins and transcriptional regulatory sequences enhance transgene expression.

OBJECTIVE: To characterize the adenoviral properties required to enhance intracellular transgene expression for gene therapy. METHODS: Primary human fibroblasts and macrophages were infected with standard replication-defective adenoviruses, adenoviral vectors containing modified fiber coat proteins expressing Arg-Gly-Asp (RGD) or heparin sulfate binding moieties, or a tetracycline-regulatable transgene transcription system. Each of these vectors expressed the beta-galactosidase gene (beta-Gal), which was quantified by flow cytometry. Ankle joints from rats with adjuvant induced arthritis were transduced intraarticularly with each of the vectors and B-Gal expression was quantified by flow cytometry. RESULTS: Primary human fibroblasts and macrophages displayed marked increases in transgene expression from both modified fiber protein vectors and from the tetracycline-regulatable vector, compared to an unmodified vector expressing the transgene from the cytomegalovirus promoter/enhancer. In the rat model, the modified fiber protein vectors and the tetracycline-regulatable vector system also displayed increased transgene expression in inflamed rat joints. CONCLUSION: Adenovirus attachment and uptake by cells and promoter strength limit transgene expression from conventional adenoviral vectors in models of rheumatoid arthritis.

Adenoviridae↗

Angiogenesis and chemokines in rheumatoid arthritis and other systemic inflammatory rheumatic diseases.

Angiogenesis, the formation of new vessels, is important in the pathogenesis of rheumatoid arthritis (RA) and other inflammatory diseases. Chemotactic cytokines termed chemokines mediate the ingress of leukocytes, including neutrophils and monocytes into the inflamed synovium. In this review, authors discuss the role of the most important angiogenic factors and angiogenesis inhibitors, as well as relevant chemokines and chemokine receptors involved in chronic inflammatory rheumatic diseases. RA was chosen as a prototype to discuss these issues, as the majority of studies on the role of angiogenesis and chemokines in inflammatory diseases were carried out in arthritis. However, other systemic inflammatory (autoimmune) diseases including systemic lupus erythematosus (SLE), systemic sclerosis (SSc), Sjögren's syndrome (SS), mixed connective tissue disease (MCTD), polymyositis/dermatomyositis (PM/DM) and systemic vasculites are also discussed in this context. As a number of chemokines may also play a role in neovascularization, this issue is also described here. Apart from discussing the pathogenic role of angiogenesis and chemokines, authors also review the regulation of angiogenesis and chemokine production by other inflammatory mediators, as well as the important relevance of neovascularization and chemokines for antirheumatic intervention.

Angiogenesis Inhibitors↗