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.
Journal of the American Animal Hospital Association
Schistosomiasis is an uncommonly reported disease that usually causes weight loss, anemia, and ga... more Schistosomiasis is an uncommonly reported disease that usually causes weight loss, anemia, and gastrointestinal signs. A 6-year-old, neutered male dog developed membranoproliferative glomerulonephritis concurrent with infection with the trematode parasite Heterobilharzia americana. At presentation, the dog had proteinuria, hypoalbuminemia, hyperglobulinemia, and anemia. Diagnosis was based upon the histopathological appearance of the kidney. Clinical signs, biochemical and hematological abnormalities, and proteinuria resolved following treatment with fenbendazole and praziquantel. Fecal examination by saline sedimentation, miracidia hatching, or Heterobilharzia polymerase chain reaction assay may be indicated when examining a dog that is presented with unexplained glomerulonephritis and is from an endemic area.
A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral l... more A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum.
To describe the prevalence, location and clinical significance of abnormal gas accumulations in d... more To describe the prevalence, location and clinical significance of abnormal gas accumulations in dogs and cats detected on computerised tomography images. Retrospective evaluation of all canine and feline computed tomography examinations (292 pre-contrast and 219 post-contrast) performed in a 12-month time period. All studies were evaluated for the presence of venous air emboli. The location of intravenous gas was noted and the volume of intravenous air emboli was estimated visually. The medical records of animals with venous air embolism were reviewed for signs of cardiopulmonary complications. The overall prevalence of air embolism on pre- and incidence on post-contrast images was 4 · 5 and 2 · 3%, respectively. The prevalence of air embolism on pre-contrast and incidence on post-contrast thoracic images was 35 · 7 and 14 · 2%, respectively. The volume of venous air was generally small and the most common was in an axillary vein. None of the animals had any cardiopulmonary complica...
We examined the expression and participation of CCR6 and its ligand MIP-3α in rheumatoid arthriti... more We examined the expression and participation of CCR6 and its ligand MIP-3α 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-3α than osteoarthritis (OA), indicating a potential role for MIP-3α in RA. IL-1β, IL-18, and TNF-α stimulated RA fibroblast
Laboratory investigation; a journal of technical methods and pathology, 2003
We examined the expression and participation of CCR6 and its ligand MIP-3alpha in rheumatoid arth... more 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, ...
To determine the role of α(1,2)-linked fucosylation of proteins by fucosyltransferase 1 (FUT1) in... more To determine the role of α(1,2)-linked fucosylation of proteins by fucosyltransferase 1 (FUT1) in rheumatoid arthritis (RA) angiogenesis. Analysis of α(1,2)-linked fucosylated proteins in synovial tissue (ST) samples was performed by immunohistologic staining. Expression of α(1,2)-linked fucosylated angiogenic chemokine in synovial fluid (SF) was determined by immunoprecipitation and lectin blotting. To determine the angiogenic role of α(1,2)-linked fucosylated proteins in RA, we performed human dermal microvascular endothelial cell (HMVEC) chemotaxis and Matrigel assays using sham-depleted and α(1,2)-linked fucosylated protein-depleted RA SF samples. To examine the production of proangiogenic chemokines by FUT1 in HMVECs, cells were transfected with FUT1 sense or antisense oligonucleotides, and enzyme-linked immunosorbent assay was performed. We then studied mouse lung endothelial cell (EC) chemotaxis using wild-type and FUT1 gene-deficient mouse lung ECs. RA ST endothelial cells showed high expression of α(1,2)-linked fucosylated proteins compared to normal ST. The expression of α(1,2)-linked fucosylated monocyte chemoattractant protein 1 (MCP-1)/CCL2 was significantly elevated in RA SF compared with osteoarthritis SF. Depletion of α(1,2)-linked fucosylated proteins in RA SF induced less HMVEC migration and tube formation than occurred in sham-depleted RA SF. We found that blocking FUT1 expression in ECs resulted in decreased MCP-1/CCL2 and RANTES/CCL5 production. Finally, we showed that FUT1 regulates EC migration in response to vascular endothelial cell growth factor. Our findings indicate that α(1,2)-linked fucosylation by FUT1 may be an important new target for angiogenic diseases such as RA.
Aminopeptidase N/CD13 (EC 3.4.11.2) is a metalloproteinase expressed by fibroblast-like synoviocy... more Aminopeptidase N/CD13 (EC 3.4.11.2) is a metalloproteinase expressed by fibroblast-like synoviocytes (FLS). It has been suggested that CD13 can act chemotactically for T cells in rheumatoid arthritis (RA). We undertook this study to measure CD13 in vivo and in vitro in RA samples and to determine whether CD13 could play a role in the homing of T cells to the RA joint. Interleukin-17-treated FLS were used to immunize mice, from which a novel anti-human CD13 monoclonal antibody (mAb), 591.1D7.34, was developed. The mAb 591.1D7.34 and a second anti-CD13 mAb, WM15, were used to develop a novel enzyme-linked immunosorbent assay (ELISA) for CD13, and CD13 enzymatic activity was measured in parallel. Chemotaxis of cytokine-activated T cells was measured by a chemotaxis-under-agarose assay. We detected substantial amounts of CD13 in synovial fluid (SF), sera, FLS lysates, and culture supernatants by ELISA, with a significant increase in CD13 in RA SF when compared to osteoarthritis SF. CD13...
The selectins, along with very late antigen-4 and CD44, have been implicated in mediating leukocy... more 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 m...
Journal of the American Animal Hospital Association, 2015
A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and... more A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and vomiting. On physical examination, the dog was painful on abdominal palpation. A torsed intra-abdominal testis was diagnosed via abdominal ultrasonography and radiography. Laparoscopy was used to identify and remove the torsed testis. The dog recovered uneventfully and was described as doing well by the owners at the 6 mo follow-up telephone contact. This is the first report of an abdominal testicular torsion treated with laparoscopy.
The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspe... more The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspected to have renal dysfunction. Focal increases in echogenicity have been attributed to neoplasia, infection, calcification, fibrosis, gas, and infarction. Anisotropic backscatter has been described as a source of focally increased renal cortical echogenicity in several species. The source of anisotropy appears to be the medullary rays, which are oriented perpendicular to the renal capsule. Spatial compound imaging (SCI) is an ultrasound setting that uses beam steering to acquire and average several overlapping scans of an object from different view angles, creating a compound image that is updated in real time. The impact of insonation angle and SCI on renal cortical echogenicity was evaluated ex vivo in eight kidneys from four dogs. Significant angle-dependent differences in cortical echogenicity were detected with both microconvex and linear transducers (P < 0.0001). Furthermore, the angle-dependent echogenicity differences persisted when SCI mode was used. Our finding that echogenicity was increased using a perpendicular insonation angle (90°) relative to the tubules, compared to a parallel insonation angle (0°) should assist in the interpretation of ultrasonographic images of the dog kidney.
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.
The nuclear DNA-binding protein DEK is an autoantigen that has been implicated in the regulation ... more The nuclear DNA-binding protein DEK is an autoantigen that has been implicated in the regulation of transcription, chromatin architecture, and mRNA processing. We demonstrate here that DEK is actively secreted by macrophages and is also found in synovial fluid samples from patients with juvenile arthritis. Secretion of DEK is modulated by casein kinase 2, stimulated by interleukin-8, and inhibited by dexamethasone and cyclosporine A, consistent with a role as a proinflammatory molecule. DEK is secreted in both a free form and in exosomes, vesicular structures in which transcription-modulating factors such as DEK have not previously been found. Furthermore, DEK functions as a chemotactic factor, attracting neutrophils, CD8 ؉ T lymphocytes, and natural killer cells. Therefore, the DEK autoantigen, previously described as a strictly nuclear protein, is secreted and can act as an extracellular chemoattractant, suggesting a direct role for DEK in inflammation.
Journal of Pharmacology and Experimental Therapeutics, 2014
Systemic sclerosis (SSc), or scleroderma, similar to many fibrotic disorders, lacks effective the... more Systemic sclerosis (SSc), or scleroderma, similar to many fibrotic disorders, lacks effective therapies. Current trials focus on anti-inflammatory drugs or targeted approaches aimed at one of the many receptor mechanisms initiating fibrosis. In light of evidence that a myocardin-related transcription factor (MRTF)-and serum response factor (SRF)-regulated gene transcriptional program induced by Rho GTPases is essential for myofibroblast activation, we explored the hypothesis that inhibitors of this pathway may represent novel antifibrotics. MRTF/SRF-regulated genes show spontaneously increased expression in primary dermal fibroblasts from patients with diffuse cutaneous SSc. A novel small-molecule inhibitor of MRTF/SRF-regulated transcription (CCG-203971) inhibits expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and collagen 1 (COL1A2) in both SSc fibroblasts and in lysophosphatidic acid (LPA)-and transforming growth factor β (TGFβ)-stimulated fibroblasts. In vivo treatment with CCG-203971 also prevented bleomycin-induced skin thickening and collagen deposition. Thus, targeting the MRTF/SRF gene transcription pathway could provide an efficacious new approach to therapy for SSc and other fibrotic disorders.
Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial ... more 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.
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.
Journal of the American Animal Hospital Association
Schistosomiasis is an uncommonly reported disease that usually causes weight loss, anemia, and ga... more Schistosomiasis is an uncommonly reported disease that usually causes weight loss, anemia, and gastrointestinal signs. A 6-year-old, neutered male dog developed membranoproliferative glomerulonephritis concurrent with infection with the trematode parasite Heterobilharzia americana. At presentation, the dog had proteinuria, hypoalbuminemia, hyperglobulinemia, and anemia. Diagnosis was based upon the histopathological appearance of the kidney. Clinical signs, biochemical and hematological abnormalities, and proteinuria resolved following treatment with fenbendazole and praziquantel. Fecal examination by saline sedimentation, miracidia hatching, or Heterobilharzia polymerase chain reaction assay may be indicated when examining a dog that is presented with unexplained glomerulonephritis and is from an endemic area.
A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral l... more A 13-year-old neutered female Labrador retriever had inspiratory dyspnea secondary to bilateral laryngeal paralysis. Radiographically, there was pectus excavatum with a mediastinal shift to the right. Arytenoid lateralization was performed, relieving the upper respiratory obstruction, and the sternal deformity also resolved. Chronic upper respiratory obstruction should be considered in dogs with pectus excavatum. Furthermore, correction of upper respiratory obstruction has the potential to result in resolution of pectus excavatum.
To describe the prevalence, location and clinical significance of abnormal gas accumulations in d... more To describe the prevalence, location and clinical significance of abnormal gas accumulations in dogs and cats detected on computerised tomography images. Retrospective evaluation of all canine and feline computed tomography examinations (292 pre-contrast and 219 post-contrast) performed in a 12-month time period. All studies were evaluated for the presence of venous air emboli. The location of intravenous gas was noted and the volume of intravenous air emboli was estimated visually. The medical records of animals with venous air embolism were reviewed for signs of cardiopulmonary complications. The overall prevalence of air embolism on pre- and incidence on post-contrast images was 4 · 5 and 2 · 3%, respectively. The prevalence of air embolism on pre-contrast and incidence on post-contrast thoracic images was 35 · 7 and 14 · 2%, respectively. The volume of venous air was generally small and the most common was in an axillary vein. None of the animals had any cardiopulmonary complica...
We examined the expression and participation of CCR6 and its ligand MIP-3α in rheumatoid arthriti... more We examined the expression and participation of CCR6 and its ligand MIP-3α 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-3α than osteoarthritis (OA), indicating a potential role for MIP-3α in RA. IL-1β, IL-18, and TNF-α stimulated RA fibroblast
Laboratory investigation; a journal of technical methods and pathology, 2003
We examined the expression and participation of CCR6 and its ligand MIP-3alpha in rheumatoid arth... more 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, ...
To determine the role of α(1,2)-linked fucosylation of proteins by fucosyltransferase 1 (FUT1) in... more To determine the role of α(1,2)-linked fucosylation of proteins by fucosyltransferase 1 (FUT1) in rheumatoid arthritis (RA) angiogenesis. Analysis of α(1,2)-linked fucosylated proteins in synovial tissue (ST) samples was performed by immunohistologic staining. Expression of α(1,2)-linked fucosylated angiogenic chemokine in synovial fluid (SF) was determined by immunoprecipitation and lectin blotting. To determine the angiogenic role of α(1,2)-linked fucosylated proteins in RA, we performed human dermal microvascular endothelial cell (HMVEC) chemotaxis and Matrigel assays using sham-depleted and α(1,2)-linked fucosylated protein-depleted RA SF samples. To examine the production of proangiogenic chemokines by FUT1 in HMVECs, cells were transfected with FUT1 sense or antisense oligonucleotides, and enzyme-linked immunosorbent assay was performed. We then studied mouse lung endothelial cell (EC) chemotaxis using wild-type and FUT1 gene-deficient mouse lung ECs. RA ST endothelial cells showed high expression of α(1,2)-linked fucosylated proteins compared to normal ST. The expression of α(1,2)-linked fucosylated monocyte chemoattractant protein 1 (MCP-1)/CCL2 was significantly elevated in RA SF compared with osteoarthritis SF. Depletion of α(1,2)-linked fucosylated proteins in RA SF induced less HMVEC migration and tube formation than occurred in sham-depleted RA SF. We found that blocking FUT1 expression in ECs resulted in decreased MCP-1/CCL2 and RANTES/CCL5 production. Finally, we showed that FUT1 regulates EC migration in response to vascular endothelial cell growth factor. Our findings indicate that α(1,2)-linked fucosylation by FUT1 may be an important new target for angiogenic diseases such as RA.
Aminopeptidase N/CD13 (EC 3.4.11.2) is a metalloproteinase expressed by fibroblast-like synoviocy... more Aminopeptidase N/CD13 (EC 3.4.11.2) is a metalloproteinase expressed by fibroblast-like synoviocytes (FLS). It has been suggested that CD13 can act chemotactically for T cells in rheumatoid arthritis (RA). We undertook this study to measure CD13 in vivo and in vitro in RA samples and to determine whether CD13 could play a role in the homing of T cells to the RA joint. Interleukin-17-treated FLS were used to immunize mice, from which a novel anti-human CD13 monoclonal antibody (mAb), 591.1D7.34, was developed. The mAb 591.1D7.34 and a second anti-CD13 mAb, WM15, were used to develop a novel enzyme-linked immunosorbent assay (ELISA) for CD13, and CD13 enzymatic activity was measured in parallel. Chemotaxis of cytokine-activated T cells was measured by a chemotaxis-under-agarose assay. We detected substantial amounts of CD13 in synovial fluid (SF), sera, FLS lysates, and culture supernatants by ELISA, with a significant increase in CD13 in RA SF when compared to osteoarthritis SF. CD13...
The selectins, along with very late antigen-4 and CD44, have been implicated in mediating leukocy... more 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 m...
Journal of the American Animal Hospital Association, 2015
A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and... more A 6 mo old male puppy was presented as an emergency for an acute onset of lethargy, ptyalism, and vomiting. On physical examination, the dog was painful on abdominal palpation. A torsed intra-abdominal testis was diagnosed via abdominal ultrasonography and radiography. Laparoscopy was used to identify and remove the torsed testis. The dog recovered uneventfully and was described as doing well by the owners at the 6 mo follow-up telephone contact. This is the first report of an abdominal testicular torsion treated with laparoscopy.
The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspe... more The echogenicity of the renal cortex is an important parameter to consider in dogs that are suspected to have renal dysfunction. Focal increases in echogenicity have been attributed to neoplasia, infection, calcification, fibrosis, gas, and infarction. Anisotropic backscatter has been described as a source of focally increased renal cortical echogenicity in several species. The source of anisotropy appears to be the medullary rays, which are oriented perpendicular to the renal capsule. Spatial compound imaging (SCI) is an ultrasound setting that uses beam steering to acquire and average several overlapping scans of an object from different view angles, creating a compound image that is updated in real time. The impact of insonation angle and SCI on renal cortical echogenicity was evaluated ex vivo in eight kidneys from four dogs. Significant angle-dependent differences in cortical echogenicity were detected with both microconvex and linear transducers (P < 0.0001). Furthermore, the angle-dependent echogenicity differences persisted when SCI mode was used. Our finding that echogenicity was increased using a perpendicular insonation angle (90°) relative to the tubules, compared to a parallel insonation angle (0°) should assist in the interpretation of ultrasonographic images of the dog kidney.
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.
The nuclear DNA-binding protein DEK is an autoantigen that has been implicated in the regulation ... more The nuclear DNA-binding protein DEK is an autoantigen that has been implicated in the regulation of transcription, chromatin architecture, and mRNA processing. We demonstrate here that DEK is actively secreted by macrophages and is also found in synovial fluid samples from patients with juvenile arthritis. Secretion of DEK is modulated by casein kinase 2, stimulated by interleukin-8, and inhibited by dexamethasone and cyclosporine A, consistent with a role as a proinflammatory molecule. DEK is secreted in both a free form and in exosomes, vesicular structures in which transcription-modulating factors such as DEK have not previously been found. Furthermore, DEK functions as a chemotactic factor, attracting neutrophils, CD8 ؉ T lymphocytes, and natural killer cells. Therefore, the DEK autoantigen, previously described as a strictly nuclear protein, is secreted and can act as an extracellular chemoattractant, suggesting a direct role for DEK in inflammation.
Journal of Pharmacology and Experimental Therapeutics, 2014
Systemic sclerosis (SSc), or scleroderma, similar to many fibrotic disorders, lacks effective the... more Systemic sclerosis (SSc), or scleroderma, similar to many fibrotic disorders, lacks effective therapies. Current trials focus on anti-inflammatory drugs or targeted approaches aimed at one of the many receptor mechanisms initiating fibrosis. In light of evidence that a myocardin-related transcription factor (MRTF)-and serum response factor (SRF)-regulated gene transcriptional program induced by Rho GTPases is essential for myofibroblast activation, we explored the hypothesis that inhibitors of this pathway may represent novel antifibrotics. MRTF/SRF-regulated genes show spontaneously increased expression in primary dermal fibroblasts from patients with diffuse cutaneous SSc. A novel small-molecule inhibitor of MRTF/SRF-regulated transcription (CCG-203971) inhibits expression of connective tissue growth factor (CTGF), α-smooth muscle actin (α-SMA), and collagen 1 (COL1A2) in both SSc fibroblasts and in lysophosphatidic acid (LPA)-and transforming growth factor β (TGFβ)-stimulated fibroblasts. In vivo treatment with CCG-203971 also prevented bleomycin-induced skin thickening and collagen deposition. Thus, targeting the MRTF/SRF gene transcription pathway could provide an efficacious new approach to therapy for SSc and other fibrotic disorders.
Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease characterized by synovial ... more 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.
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Papers by Jeffrey Ruth