bluuebunny/crossref_metadata_2025 huggingface dataset:
A Membrane Associated mCherry Fluorescent Reporter Line for Studying Vascular Remodeling and Cardiac Function During Murine Embryonic Development
Authors: Larina Irina V. , Shen Wei , Kelly Olivia G. , Hadjantonakis Anna‐Katerina , Baron Margaret H. , Dickinson Mary E.
Published: February 2009

The development of the cardiovascular system is a highly dynamic process dependent on multiple signaling pathways regulating proliferation, differentiation, migration, cell–cell and cell‐matrix interactions. To characterize cell and tissue dynamics during the formation of the cardiovascular system in mice, we generated a novel transgenic mouse line, Tg(Flk1::myr‐mCherry), in which endothelial cell membranes are brightly labeled with mCherry, a red fluorescent protein. Tg(Flk1::myr‐mCherry) mice are viable, fertile, and do not exhibit any developmental abnormalities. High levels of mCherry are expressed in the embryonic endothelium and endocardium, and expression is also observed in capillaries in adult animals. Targeting of the fluorescent protein to the cell membrane allows for subcellular imaging and cell tracking. By acquiring confocal time lapses of live embryos cultured on the microscope stage, we demonstrate that the newly generated transgenic model beautifully highlights the sprouting behaviors of endothelial cells during vascular plexus formation. We have also used embryos from this line to imaging the endocardium in the beating embryonic mouse heart, showing that Tg(Flk1::myr‐mCherry) mice are suitable for the characterization of cardio dynamics. Furthermore, when combined with the previously described Tg(Flk1::H2B‐EYFP) line, cell number in addition to cell architecture is revealed, making it possible to determine how individual endothelial cells contribute to the structure of the vessel. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
3D Cryo‐Imaging: A Very High‐Resolution View of the Whole Mouse
Authors: Roy Debashish , Steyer Grant J. , Gargesha Madhusudhana , Stone Meredith E. , Wilson David L.
Published: February 2009

We developed the Case Cryo‐imaging system that provides information rich, very high‐resolution, color brightfield, and molecular fluorescence images of a whole mouse using a section‐and‐image block‐face imaging technology. The system consists of a mouse‐sized, motorized cryo‐microtome with special features for imaging, a modified, brightfield/fluorescence microscope, and a robotic xyz imaging system positioner, all of which is fully automated by a control system. Using the robotic system, we acquired microscopic tiled images at a pixel size of 15.6 μm over the block face of a whole mouse sectioned at 40 μm, with a total data volume of 55 GB. Viewing 2D images at multiple resolutions, we identified small structures such as cardiac vessels, muscle layers, villi of the small intestine, the optic nerve, and layers of the eye. Cryo‐imaging was also suitable for imaging embryo mutants in 3D. A mouse, in which enhanced green fluorescent protein was expressed under gamma actin promoter in smooth muscle cells, gave clear 3D views of smooth muscle in the urogenital and gastrointestinal tracts. With cryo‐imaging, we could obtain 3D vasculature down to 10 μm, over very large regions of mouse brain. Software is fully automated with fully programmable imaging/sectioning protocols, email notifications, and automatic volume visualization. With a unique combination of field‐of‐view, depth of field, contrast, and resolution, the Case Cryo‐imaging system fills the gap between whole animal in vivo imaging and histology. histology. Anat Rec, 292:342–351, 2009. © 2009 Wiley‐Liss, Inc.
Identification of a Tendon Phenotype in GDF6 Deficient Mice
Authors: Mikic Borjana , Rossmeier Kerri , Bierwert Louann
Published: February 2009

Increasing evidence suggests that the growth/differentiation factors, GDFs 5, 6, and 7 in particular, may play a role in tendon and ligament biology. Mice with genetic mutations in Gdf5 have altered tendon composition and mechanical behavior, whereas animals with functional null mutations in Gdf7 have a more subtle tendon phenotype. The present study demonstrates for the first time that a null mutation in Gdf6 is associated with substantially lower levels of tail tendon collagen content (−33%) in 4‐week‐old male mice, which has direct functional consequences for the mechanical integrity of the tissue (45–50% reduction in material properties). These data support a role for GDF6 in tendon matrix modeling. Anat Rec, 292:396–400, 2009. © 2009 Wiley‐Liss, Inc.
Acetylcholinesterase Activity, Choline Acetyltransferase and Vesicular Acetylcholine Transporter Immunoreactivities in the Rat Adrenal Gland During Postnatal Development
Authors: Murabayashi Hiroshi , Kuramoto Hirofumi , Ishikawa Katsushi , Iwamoto Jun , Miyakawa Kiyoshi , Tanaka Kunio , Sekikawa Mitsuo , Sasaki Motoki , Kitamura Nobuo , Oomori Yukio
Published: February 2009

From postnatl‐day‐0 to postnatal‐day‐2, a few acetylcholinesterase (AChE)‐active and choline acetytransferase (ChAT)‐immunoreactive nerve fibers and relatively numerous vesicular acetylcholine transporter (VAChT)‐immunoreactive puncta were observed in the rat adrenal medulla. Despite relatively numerous clear vesicles in the nerve fibers, the synthesis and hydrolysis of acetylcholine may not be fully activated until postnatal‐day‐2. The number of AChE‐active and ChAT‐immunoreactive nerve fibers dramatically increased and that of VAChT‐immunoreactive puncta gradually increased from postnatal‐day‐3 to postnatal‐week‐1. The synthesis and hydrolysis of acetylcholine may be dramatically activated in the nerve fibers of the medulla until postnatal‐week‐1. From postnatal‐week‐2 to postnatal‐week‐3, the number of AChE‐active and the ChAT‐immunoreactive nerve fibers gradually increased and reached the adult levels. The VAChT‐immunoreactive puncta per unit area was maximum number at postnatal‐week‐2. The synthesis and hydrolysis of acetylcholine in the nerve fibers of the medulla may be completed between postnatal‐week‐2 to postnatal‐week‐3. The diameter of the VAChT‐immunoreactive puncta gradually increased from postnatal‐day‐0 with aging. However, the number of the VAChT‐immunoreactive puncta gradually decreased from postnatal‐week‐2 onwards. In electron‐microscopy, the VAChT‐immunoreactive deposits were seen in clusters of clear vesicles, and the diameter of the nerve fibers and the number of clear vesicles at postnatal‐week‐8 increased compared with those at postnatal‐week‐2. The AChE‐active, ChAT‐immunoreactive, and VAChT‐immunoreactive nerve fibers observed around noradrenaline (NA) cells were denser than those around adrenaline (A) cells in the medulla at postnatal‐week‐8. These suggest that the preferential innervation of NA and A cells may cause the differential secretion NA and A. Anat Rec, 292:371–380, 2009. © 2009 Wiley‐Liss, Inc.
μ‐Opioid Receptor Redistribution in the Locus Coeruleus Upon Precipitation of Withdrawal in Opiate‐Dependent Rats
Authors: Scavone Jillian L. , Van Bockstaele Elisabeth J.
Published: February 2009

Administration of μ‐opioid receptor (MOR) agonists is known to produce adaptive changes within noradrenergic neurons of the rat locus coeruleus (LC). Alterations in the subcellular distribution of MOR have been shown to occur in the LC in response to full agonists and endogenous peptides; however, there is considerable debate in the literature whether trafficking of MOR occurs after chronic exposure to the partial‐agonist morphine. In the present study, we examined adaptations in MOR after chronic opioid exposure using immunofluorescence and electron microscopy (EM), using receptor internalization as a functional endpoint. MOR trafficking in LC neurons was characterized in morphine‐dependent rats that were given naltrexone at a dose known to precipitate withdrawal. After chronic morphine exposure, a subtle redistribution of MOR immunoreactivity from the membrane to the cytosol was detected within dendrites of LC neurons. Interestingly, an acute injection of naltrexone in rats exposed to chronic morphine produced a robust internalization of MOR, whereas administration of naltrexone failed to do so in naïve animals. These findings provide anatomical evidence for modified regulation of MOR trafficking after chronic morphine treatment in brain noradrenergic neurons. Adaptations in the MOR signaling pathways that regulate internalization may occur as a consequence of chronic treatment and precipitation of withdrawal. Mechanisms underlying this effect might include differential MOR regulation in the LC, or downstream effects of withdrawal‐induced enkephalin (ENK) release from afferents to the LC. Anat Rec, 292:401–411, 2009. © 2009 Wiley‐Liss, Inc.
Protective Effect of Total Flavones of Abelmoschus manihot L. Medic Against Poststroke Depression Injury in Mice and Its Action Mechanism
Authors: Liu Mei , Jiang Qiu‐Hong , Hao Ji‐Li , Zhou Lan‐Lan
Published: February 2009

Total flavones of Abelmoschus manihot L. Medic (TFA) is the major active component isolated from the traditional Chinese herb Abelmoschus manihot L. Medic. We investigated the protective effect of TFA against poststroke depression (PSD) injury in mice and its action mechanism. A mouse model of PSD was induced by middle cerebral artery occlusion (MACO) 30 min/reperfusion, followed by isolation feeding and chronic unpredictable mild stress for 2 weeks. Treatment groups received TFA at three different doses (160, 80, and 40 mg/kg, p.o.) or fluoxetine (Flu, 2.5 mg/kg, p.o.) daily for 24 days. Change in behavior, brain tissue malondialdehyde (MDA) levels, and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) were measured. The expression of brain‐derived neurotrophic factor (BDNF) was detected by immunohistochemistry, and mRNA expression of BDNF and cAMP response element‐binding protein (CREB) analyzed by reverse transcription‐polymerase chain reaction (RT‐PCR). Treatment with TFA (160, 80, and 40 mg/kg) significantly ameliorated mice escape‐directed behavioral impairment induced by PSD, markedly reduced MDA levels, and increased the activity of SOD, GSH‐Px close to normal levels. TFA administration also attenuated PSD‐induced neuronal death/losses, upregulated expression of BDNF both at mRNA and protein levels, as well as CREB mRNA levels. TFA had a protective effect against PSD injury in mice. Cardioprotection involves the inhibition of lipid peroxidation and upregulation of BDNF‐CREB levels in the hippocampus, which may also be important mechanism of its antidepressants. This potential protection makes TFA a promising therapeutic agent for the PSD. Anat Rec, 292:412–422, 2009. © 2009 Wiley‐Liss, Inc.
Promising Diagnostic Biomarkers for Primary Biliary Cirrhosis Identified With Magnetic Beads and MALDI‐TOF‐MS
Authors: Li Yong‐Zhe , Hu Chao‐Jun , Leng Xiao‐Mei , Zhao Guan‐Fei , Li Ning , Xu Yang
Published: February 2009

(PBC) is not a rare disease worldwide. Most patients are diagnosed at the advanced stage, primarily because there are not yet any valid biomarkers available for early diagnosis. Useful biomarkers are absolutely necessary for early detection of PBC. Fortunately, the use of MALDI‐TOF‐MS and pattern recognition software has been successful in finding specific markers for the early detection of the disease. To screen for potential protein biomarkers in the serum for diagnosing PBC, MALDI‐TOF‐MS combined with magnetic beads and pattern recognition software was used to investigate 119 serum samples from 44 patients with PBC, 32 controls with other hepatic disease, and 43 healthy controls. A total of 69 discriminant m/z peaks were identified as being associated with PBC. Of them, the m/z peaks at 3445, 4260, 8133, and 16,290 were used to construct a model for the diagnosis of PBC. This diagnostic model can distinguish PBC from non‐PBC controls with a sensitivity of 93.3% and a specificity of 95.1%. In our blind test, it demonstrated good sensitivity and specificity: 92.9% and 82.4%, respectively. These results indicate that useful serum biomarkers for PBC can be discovered by MALDI‐TOF‐MS combined with the use of magnetic beads and pattern recognition software. The pattern of multiple markers provides a powerful and reliable diagnostic method for PBC with high sensitivity and specificity. Anat Rec, 292:455–460, 2009. © 2009 Wiley‐Liss, Inc.
Intraarticular injection of anakinra in osteoarthritis of the knee: A multicenter, randomized, double‐blind, placebo‐controlled study
Authors: Chevalier X. , Goupille P. , Beaulieu A. D. , Burch F. X. , Bensen W. G. , Conrozier T. , Loeuille D. , Kivitz A. J. , Silver D. , Appleton B. E.
Published: February 2009

Objective

To evaluate the clinical response, safety, and tolerability of a single intraarticular injection of anakinra in patients with symptomatic osteoarthritis (OA) of the knee.

Methods

Patients with OA of the knee were enrolled in a multicenter, double‐blind, placebo‐controlled study and randomized 2:1:2 to receive a single intraarticular injection of placebo, anakinra 50 mg, or anakinra 150 mg in their symptomatic knee. Patients were evaluated for 12 weeks postinjection. The primary end point was the change in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score from baseline to week 4. Safety assessments included the evaluation of adverse events (AEs), laboratory tests, and vital signs. Pharmacokinetic parameters were assessed in a subset of patients.

Results

Of 170 patients who enrolled, 160 (94%) completed the study. The mean improvements from baseline to week 4 in the WOMAC score were not statistically different between the placebo group and the patients who received 50 mg of anakinra (P = 0.67) or 150 mg of anakinra (P = 0.77). Anakinra was well tolerated. No withdrawals due to AEs or serious AEs, and no serious infections or deaths were reported. No clinically significant trends were noted in laboratory values or vital signs. Pharmacokinetic parameters demonstrated that the mean terminal half‐life of anakinra in serum after intraarticular injection was ∼4 hours.

Conclusion

Anakinra was well tolerated as a single 50‐mg or 150‐mg intraarticular injection in patients with OA of the knee. However, anakinra was not associated with improvements in OA symptoms compared with placebo.
Cost‐utility analysis of treatment strategies in patients with recent‐onset rheumatoid arthritis
Authors: Van den Hout Wilbert B. , Goekoop‐Ruiterman Yvonne P. M. , Allaart Cornelia F. , De Vries‐Bouwstra Jeska K. , M. Hazes J. Mieke , Kerstens Pit J. S. M. , Van Zeben Derkjen , Hulsmans Harry M. J. , De Jonge‐Bok Johanna M. , De Sonnaville Peter B. J. , Dijkmans Ben A. C. , Breedveld Ferdinand C.
Published: February 2009

Objective

To evaluate societal costs and quality‐adjusted life years (QALYs) of treatment strategies for patients with recent‐onset active rheumatoid arthritis (RA).

Methods

Patients (n = 508) were randomly allocated to 1 of 4 treatment strategy groups: sequential monotherapy, step‐up combination therapy, initial combination therapy with prednisone, or initial combination therapy with infliximab. For 2 years, patients reported cost and utility measures.

Results

Average QALYs (ideally 2.00) for groups 1–4 were 1.29, 1.31, 1.32, and 1.41, respectively, for the British EuroQol (P ≤ 0.05 for group 4 versus groups 1–3); 1.41, 1.43, 1.44, and 1.52, respectively, for the Dutch EuroQol (P ≤ 0.05 for group 4 versus groups 1–3); and 1.38, 1.38, 1.39, and 1.44, respectively, for the Short Form 6D (P ≤ 0.05 for group 4 versus groups 1–3). The Time Trade‐Off showed no significant differences. In the primary analysis, using the friction cost method to value productivity, the cost‐utility ratio for group 4 against the next best alternative was estimated at €130,000 (95% confidence interval €27,000, €3,000,000) per QALY. Using the human capital method, the value of sustained productivity in group 4 largely compensated for the extra medication costs.

Conclusion

Initial combination therapy with infliximab for patients with recent‐onset active RA resulted in significantly better quality of life than other strategies. Using the friction cost method, costs to achieve this improvement are generally considered too high, and initial combination therapy with prednisone should be preferred. However, depending on the extent to which productivity is valued, infliximab costs could be largely compensated for by savings on productivity. Since patterns of infliximab use had not yet stabilized after 2 years, longer followup may change the economic conclusions.
Neglected external validity in reports of randomized trials: The example of hip and knee osteoarthritis
Authors: Ahmad Nizar , Boutron Isabelle , Moher David , Pitrou Isabelle , Roy Carine , Ravaud Philippe
Published: February 2009

Objective

To evaluate data reporting related to external validity from randomized controlled trials (RCTs) assessing pharmacologic and nonpharmacologic treatment for hip and knee osteoarthritis (OA).

Methods

All RCTs assessing pharmacologic treatments and nonpharmacologic treatments for hip and knee OA indexed between January 2002 and December 2006 were selected. A sample of 120 articles were randomly selected: 30 each assessing pharmacologic treatments, surgery or technical interventions, rehabilitation, and nonimplantable devices.

Results

The country was clearly reported in 25 (21%) reports, the setting described in 40 (33%) reports, and the number of centers in 54 (45%). Details about the centers (volume of care) were given in 24 (20%) reports. Rates were lower for surgical trials for the country (3%), the setting (3%), the number of centers (13%), and details about the centers (7%). The intervention was adequately described in all pharmacologic reports and in >80% of rehabilitation reports. The technical procedure was given in all surgical intervention trial reports, but the type of anesthesia was reported in 4 (13%), preoperative care in 2 (7%), and postoperative care in 15 (50%). The device was described in 93% of device trial reports, but the manufacturer was reported in only 33%.

Conclusion

There is low reporting of data related to external validity in reports of RCTs assessing pharmacologic and nonpharmacologic treatments for hip and knee OA.
Current risk factors for work disability associated with rheumatoid arthritis: Recent data from a US national cohort
Authors: Allaire Saralynn , Wolfe Frederick , Niu Jingbo , LaValley Michael P. , Zhang Bin , Reisine Susan
Published: February 2009

Objective

To explore, using recent data, whether and how risk factors for rheumatoid arthritis (RA) work disability may differ from previous studies.

Methods

Subjects were 953 individuals with RA from a US cohort who provided data semiannually over 18 months (years 2002–2005). A nested case–control design was used with matching on time of baseline data collection. All subjects were employed at baseline; cases were consistently not employed at followup, whereas controls remained employed. Hierarchical conditional logistic regression assessed the roles of demographic, RA disease, general health, and work factors as predictors of work disability. Recursive partitioning and causal modeling procedures were also used.

Results

Sample characteristics were mean age 51 years, 82% female, and 92% white. Older age (odds ratio [OR] 1.2, 95% confidence interval [95% CI] 1.1–1.4) and lower income (OR 1.7, 95% CI 1.0–2.7) predicted work disability, whereas more hours worked (OR 0.9, 95% CI 0.8–0.9) and preference to work full time (OR 0.2, 95% CI 0.1–0.4) or part time (OR 0.4, 95% CI 0.2–0.6) versus not to work were protective in the regression analysis. In recursive partitioning analyses, RA disease factors predicted work disability among older subjects, and functional limitation was the fourth most important factor. Job physical demand was not a significant or important factor.

Conclusion

In this contemporary data from a large RA cohort, older age, lower income, fewer working hours, and preference not to work were the risk factors for work disability. The impact of disease factors was limited to subjects ages ≥56 years. Job physical demand level had little impact.
Interleukin‐7 stimulates secretion of S100A4 by activating the JAK/STAT signaling pathway in human articular chondrocytes
Authors: Yammani Raghunatha R. , Long David , Loeser Richard F.
Published: February 2009

Objective

S100A4 has been shown to be increased in osteoarthritic (OA) cartilage and to stimulate chondrocytes to produce matrix metalloproteinase 13 (MMP‐13) through activation of the receptor for advanced glycation end products (RAGE). The aim of this study was to examine the mechanism of S100A4 secretion by chondrocytes.

Methods

Human articular chondrocytes isolated from ankle cartilage were stimulated with 10 ng/ml of interleukin‐1β (IL‐1β), IL‐6, IL‐7, or IL‐8. Cells were pretreated with either a JAK‐3 inhibitor, brefeldin A, or cycloheximide. Immunoblotting with phospho‐specific antibodies was used to determine the activation of signaling proteins. Secretion of S100A4 was measured in conditioned media by immunoblotting, and MMP‐13 was measured by enzyme‐linked immunosorbent assay.

Results

Chondrocyte secretion of S100A4 was observed after treatment with IL‐6 or IL‐8 but was much greater in cultures treated with equal amounts of IL‐7 and was not observed after treatment with IL‐1β. IL‐7 activated the JAK/STAT pathway, with increased phosphorylation of JAK‐3 and STAT‐3, leading to increased production of S100A4 and MMP‐13. Overexpression of a dominant‐negative RAGE construct inhibited the IL‐7–mediated production of MMP‐13. Pretreatment of chondrocytes with a JAK‐3 inhibitor or with cycloheximide blocked the IL‐7–mediated secretion of S100A4, but pretreatment with brefeldin A did not.

Conclusion

IL‐7 stimulates chondrocyte secretion of S100A4 via activation of JAK/STAT signaling, and then S100A4 acts in an autocrine manner to stimulate MMP‐13 production via RAGE. Since both IL‐7 and S100A4 are up‐regulated in OA cartilage and can stimulate MMP‐13 production by chondrocytes, this signaling pathway could contribute to cartilage destruction during the development of OA.
Association of the autoimmunity locus 4q27 with juvenile idiopathic arthritis
Authors: Albers H. M. , Kurreeman F. A. S. , Stoeken‐Rijsbergen G. , Brinkman D. M. C. , Kamphuis S. S. M. , van Rossum M. A. J. , Girschick H. J. , Wouters C. , Saurenmann R. K. , Hoppenreijs E. , Slagboom P. , Houwing‐Duistermaat J. J. , Verduijn W. , Huizinga T. W. J. , ten Cate R. , Toes R. E. M. , Schilham M. W.
Published: February 2009

Objective

Juvenile idiopathic arthritis (JIA) is characterized by chronic arthritis and an autoimmune etiology. In several autoimmune diseases, including rheumatoid arthritis (RA), an association with the 4q27 locus has been reported. We undertook this study to investigate the possible role of the 4q27 locus in JIA.

Methods

A case–control association study was conducted, with a total of 655 Caucasian JIA patients and 791 healthy controls divided into 2 independent sample sets. The rs6822844 marker in the 4q27 locus was genotyped.

Results

In the first and larger sample set, a 5% decrease in T allele frequency was observed in patients compared with controls (allelic odds ratio [OR] 0.72 [95% confidence interval 0.55–0.95], P = 0.019), and in the second set, a 3% decrease was observed (allelic OR 0.81 [95% confidence interval 0.61–1.09], P = 0.169). The combined data set generated an OR of 0.76 (95% confidence interval 0.62–0.93, P = 7.08 × 10−3). When the different JIA subtypes were analyzed individually, significant decreases were seen in the subtypes with a polyarticular course of disease (extended oligoarthritis [P = 0.019] and rheumatoid factor–negative polyarthritis [P = 0.038]).

Conclusion

Our findings suggest that the 4q27 locus, previously reported to be associated with RA, type 1 diabetes mellitus, celiac disease, and psoriatic arthritis, is also associated with susceptibility to JIA.
The meaning of clinical remission in polyarticular juvenile idiopathic arthritis: Gene expression profiling in peripheral blood mononuclear cells identifies distinct disease states
Authors: Knowlton Nicholas , Jiang Kaiyu , Frank Mark Barton , Aggarwal Amita , Wallace Carol , McKee Ryan , Chaser Brad , Tung Catherine , Smith Laura , Chen Yanmin , Osban Jeanette , O'Neil Kathleen , Centola Michael , McGhee Julie L. , Jarvis James N.
Published: February 2009

Objective

The development of biomarkers to predict response to therapy in polyarticular juvenile idiopathic arthritis (JIA) is an important issue in pediatric rheumatology. A critical step in this process is determining whether there is biologic meaning to clinically derived terms such as “active disease” and “remission.” The aim of this study was to use a systems biology approach to address this question.

Methods

We performed gene transcriptional profiling on children who fulfilled the criteria for specific disease states as defined by the consensus criteria developed by Wallace and colleagues. The study group comprised children with active disease (n = 14), children with clinical remission on medication (CRM; n = 9), children with clinical remission off medication (CR; n = 6), and healthy control children (n = 13). Transcriptional profiles in peripheral blood mononuclear cells (PBMCs) were obtained using Affymetrix U133 Plus 2.0 arrays.

Results

Hierarchical cluster analysis and predictive modeling demonstrated that the clinically derived criteria represent biologically distinct states. Minimal differences were seen between children with active disease and those with disease in CRM. Thus, underlying immune/inflammatory abnormalities persist despite a response to therapy. The PBMC transcriptional profiles of children whose disease was in remission did not return to normal but revealed networks of proinflammatory and antiinflammatory genes, suggesting that remission is a state of homeostasis, not a return to a normal state.

Conclusion

Gene transcriptional profiling of PBMCs revealed that clinically derived criteria for JIA disease states reflect underlying biology. We also demonstrated that neither CRM nor CR status results in resolution of the underlying inflammatory process, but that these conditions are more likely to be states of balanced homeostasis between proinflammatory and antiinflammatory mechanisms.
Tumor necrosis factor α–induced interleukin‐32 is positively regulated via the Syk/protein kinase Cδ/JNK pathway in rheumatoid synovial fibroblasts
Authors: Mun Se Hwan , Kim Jie Wan , Nah Seong Su , Ko Na Young , Lee Jun Ho , Kim Ju Dong , Kim Do Kyun , Kim Hyuk Soon , Choi Ji Da , Kim Soo Hyun , Lee Chang Keun , Park Seung Hwa , Kim Bo Kyung , Kim Hyung Sik , Kim Young Mi , Choi Wahn Soo
Published: February 2009

Objective

Interleukin‐32 (IL‐32) is a recently discovered cytokine that appears to play a critical role in human rheumatoid arthritis (RA). It is highly expressed in synovium and fibroblast‐like synoviocytes (FLS) from RA patients, but not in patients with osteoarthritis (OA). This study was undertaken to assess IL‐32 levels in RA synovial fluid (SF) and to investigate the secretion and regulation of IL‐32 in RA FLS.

Methods

FLS and SF were obtained from the joints of RA patients. The secretion and expression of IL‐32 and activation of signaling molecules were examined by enzyme‐linked immunosorbent assay, immunoblotting, immunoprecipitation, reverse transcriptase–polymerase chain reaction, and small interfering RNA (siRNA) transfection.

Results

IL‐32 levels were high in RA SF compared with OA SF. Furthermore, RA FLS expressed and secreted IL‐32 when stimulated with tumor necrosis factor α (TNFα). TNFα‐induced expression of IL‐32 was significantly suppressed, in a dose‐dependent manner, by inhibitors of Syk, protein kinase Cδ (PKCδ), and JNK and by knockdown of these kinases and c‐Jun with siRNA. We also observed that PKCδ mediated the activation of JNK and c‐Jun, and experiments using specific inhibitors and siRNA demonstrated that Syk was the upstream kinase for the activation of PKCδ.

Conclusion

The present findings suggest that IL‐32 may be a newly identified prognostic biomarker in RA, thereby adding valuable knowledge to the understanding of this disease. The results also demonstrate that the production of IL‐32 in RA FLS is regulated by Syk/PKCδ‐mediated signaling events.
Activation of cartilage matrix metalloproteinases by activated protein C
Authors: Jackson Miriam T. , Smith Margaret M. , Smith Susan M. , Jackson Christopher J. , Xue Meilang , Little Christopher B.
Published: February 2009

Objective

To investigate the role of activated protein C (APC) in cartilage degradation.

Methods

Chondrocyte expression of protein C, endothelial protein C receptor (EPCR), and thrombomodulin (TM) were evaluated by reverse transcription–polymerase chain reaction (RT‐PCR). APC was immunolocalized in developing joints and in osteoarthritic (OA) cartilage from humans. The effect of APC on aggrecan and collagen degradation was examined in explant cultures of ovine cartilage in control cultures and in cultures stimulated with interleukin‐1α (IL‐1α), tumor necrosis factor α (TNFα), or retinoic acid (RetA), using colorimetric assays and Western blotting. Chondrocyte expression of matrix metalloproteinases (MMPs), ADAMTS, and tissue inhibitor of metalloproteinases (TIMPs) was measured by RT‐PCR. MMP‐2 and MMP‐9 activity was evaluated by gelatin zymography and MMP‐13 by fluorogenic assay.

Results

Positive cellular immunostaining for APC was found at sites of MMP activity in developing joints and in OA, but not normal, cartilage. Chondrocytes expressed messenger RNA for protein C, EPCR, and TM, with the latter 2 levels increased by IL‐1α and TNFα stimulation. APC augmented aggrecan release and initiated collagen breakdown in IL‐1α–treated and TNFα‐treated cartilage, but not in normal or in RetA‐treated cartilage. APC‐stimulated aggrecan and collagen breakdown were due to MMP activity but were not associated with modulation of MMP, ADAMTS, or TIMP expression. APC resulted in MMP‐13 activation in cartilage cultures. APC could not directly activate proMMP‐13, but it was associated with increased MMP‐2 and MMP‐9 activity.

Conclusion

APC may be a relevant activator of MMPs in cartilage and may play a role in progressive cartilage degradation in arthritis.
Prevention of cartilage degeneration in a rat model of osteoarthritis by intraarticular treatment with recombinant lubricin
Authors: Flannery Carl R. , Zollner Richard , Corcoran Chris , Jones Aled R. , Root Adam , Rivera‐Bermúdez Moisés A. , Blanchet Tracey , Gleghorn Jason P. , Bonassar Lawrence J. , Bendele Alison M. , Morris Elisabeth A. , Glasson Sonya S.
Published: February 2009

Objective

Lubricin, also referred to as superficial zone protein and PRG4, is a synovial glycoprotein that supplies a friction‐resistant, antiadhesive coating to the surfaces of articular cartilage, thereby protecting against arthritis‐associated tissue wear and degradation. This study was undertaken to generate and characterize a novel recombinant lubricin protein construct, LUB:1, and to evaluate its therapeutic efficacy following intraarticular delivery in a rat model of osteoarthritis (OA).

Methods

Binding and localization of LUB:1 to cartilage surfaces was assessed by immunohistochemistry. The cartilage‐lubricating properties of LUB:1 were determined using a custom friction testing apparatus. A cell‐binding assay was performed to quantify the ability of LUB:1 to prevent cell adhesion. Efficacy studies were conducted in a rat meniscal tear model of OA. One week after the surgical induction of OA, LUB:1 or phosphate buffered saline vehicle was administered by intraarticular injection for 4 weeks, with dosing intervals of either once per week or 3 times per week. OA pathology scores were determined by histologic analysis.

Results

LUB:1 was shown to bind effectively to cartilage surfaces, and facilitated both cartilage boundary lubrication and inhibition of synovial cell adhesion. Treatment of rat knee joints with LUB:1 resulted in significant disease‐modifying, chondroprotective effects during the progression of OA, by markedly reducing cartilage degeneration and structural damage.

Conclusion

Our findings demonstrate the potential use of recombinant lubricin molecules in novel biotherapeutic approaches to the treatment of OA and associated cartilage abnormalities.
Inhibition of interleukin‐33 signaling attenuates the severity of experimental arthritis
Authors: Palmer Gaby , Talabot‐Ayer Dominique , Lamacchia Céline , Toy Dean , Seemayer Christian A. , Viatte Sébastien , Finckh Axel , Smith Dirk E. , Gabay Cem
Published: February 2009

Objective

Interleukin‐33 (IL‐33; or, IL‐1F11) was recently identified as the ligand of the IL‐1 family receptor T1/ST2. The aim of this study was to examine IL‐33 production in human and mouse joints and to investigate the role of IL‐33 and T1/ST2 in experimental arthritis.

Methods

IL‐33 expression was examined in human synovial tissue, rheumatoid arthritis (RA) synovial fibroblasts, and arthritic mouse joints. Mice with collagen‐induced arthritis (CIA) were treated with blocking anti‐ST2 antibody or control antibody beginning at the onset of disease. Arthritis severity was assessed by clinical and histologic scoring. Draining lymph node (LN) cell responses were examined ex vivo, and joint messenger RNA (mRNA) was used for expression profiling.

Results

IL‐33 was highly expressed in human RA synovium. In cultured synovial fibroblasts, IL‐33 expression was strongly induced by IL‐1β and/or tumor necrosis factor α. Furthermore, IL‐33 mRNA was detected in the joints of mice with CIA and increased during the early phase of the disease. Administration of a blocking anti‐ST2 antibody at the onset of disease attenuated the severity of CIA and reduced joint destruction. Anti‐ST2 antibody treatment was associated with a marked decrease in interferon‐γ production as well as with a more limited reduction in IL‐17 production by ex vivo–stimulated draining LN cells. Finally, RANKL mRNA levels in the joint were reduced by anti‐ST2 treatment.

Conclusion

IL‐33 is produced locally in inflamed joints, and neutralization of IL‐33 signaling has a therapeutic effect on the course of arthritis. These observations suggest that locally produced IL‐33 may contribute to the pathogenesis of joint inflammation and destruction.
Familial associations of rheumatoid arthritis with autoimmune diseases and related conditions
Authors: Hemminki Kari , Li Xinjun , Sundquist Jan , Sundquist Kristina
Published: February 2009

Objective

In the era of genome‐wide association studies, familial risks are used to estimate disease heritability and the likelihood of candidate‐gene identification. This study was undertaken to estimate associations of rheumatoid arthritis (RA) with any of 33 autoimmune diseases and related conditions among parents and offspring, singleton siblings, twins, and spouses.

Methods

The Multigeneration Register in Sweden was used as a reliable source of information on Swedish families throughout the last century. Data on autoimmune diseases in individual family members were obtained through linkage to the Hospital Discharge Register. The standardized incidence ratio (SIR) was calculated as a measure of the relative risk of RA in family members of patients with RA or any of 33 other autoimmune diseases or related conditions, as compared with the relative risk of RA in those lacking an affected family member.

Results

Among a total of 447,704 patients, 47,361 were diagnosed as having RA. The SIRs for RA were 3.02 in offspring of affected parents, 4.64 in siblings, 9.31 in multiplex families, 6.48 in twins, and 1.17 in spouses. Significant associations with the familial risk of RA in offspring according to parental proband were observed for ankylosing spondylitis (SIR 2.96), localized scleroderma (SIR 2.40), Sjögren's syndrome (SIR 2.25), systemic lupus erythematosus (SIR 2.13), systemic sclerosis (SIR 1.65), Hashimoto thyroiditis/hypothyroidism (SIR 1.54), pernicious anemia (SIR 1.53), sarcoidosis (SIR 1.40), psoriasis (SIR 1.36), Wegener's granulomatosis (SIR 1.34), and asthma or polymyalgia rheumatica (SIR 1.32).

Conclusion

This is the first study to compare the familial risks of RA in relation to a large number of autoimmune diseases and related conditions using data from a single population. The high discordant familial risks in this population suggest that there is extensive genetic sharing between RA and the associated diseases.
Is obesity a risk factor for progressive radiographic knee osteoarthritis?
Authors: Niu J. , Zhang Y. Q. , Torner J. , Nevitt M. , Lewis C. E. , Aliabadi P. , Sack B. , Clancy M. , Sharma L. , Felson D. T.
Published: February 2009

Objective

To examine whether obesity increases the risk of progression of knee osteoarthritis (OA).

Methods

We used data from the Multicenter Osteoarthritis Study, a longitudinal study of persons with or at high risk of knee OA. OA was characterized at baseline and 30 months using posteroanterior fixed‐flexion radiographs and Kellgren/Lawrence (K/L) grading, with alignment assessed on full‐extremity films. In knees with OA at baseline (K/L grade 2 or 3), progression was defined as tibiofemoral joint space narrowing on the 30‐month radiograph. In knees without OA at baseline (K/L grade 0 or 1), incident OA was defined as the development of radiographic OA at 30 months. Body mass index (BMI) at baseline was classified as normal (<25 kg/m2), overweight (25–<30 kg/m2), obese (30–<35 kg/m2), and very obese (≥35 kg/m2). The risk of progression was tested in all knees and in subgroups categorized according to alignment. Analyses were adjusted for age, sex, knee injury, and bone density.

Results

Among the 2,623 subjects (5,159 knees), 60% were women, and the mean ± SD age was 62.4 ± 8.0 years. More than 80% of subjects were overweight or obese. At baseline, 36.4% of knees had tibiofemoral OA, and of those, only one‐third were neutrally aligned. Compared with subjects with a normal BMI, those who were obese or very obese were at an increased risk of incident OA (relative risk 2.4 and 3.2, respectively [P for trend < 0.001]); this risk extended to knees from all alignment groups. Among knees with OA at baseline, there was no overall association between a high BMI and the risk of OA progression; however, an increased risk of progression was observed among knees with neutral but not varus alignment. The effect of obesity was intermediate in those with valgus alignment.

Conclusion

Although obesity was a risk factor for incident knee OA, we observed no overall relationship between obesity and the progression of knee OA. Obesity was not associated with OA progression in knees with varus alignment; however, it did increase the risk of progression in knees with neutral or valgus alignment. Therefore, weight loss may not be effective in preventing progression of structural damage in OA knees with varus alignment.
Radiologic assessment of age‐related knee joint space changes in women: A 4‐year longitudinal study
Authors: Gensburger Déborah , Arlot Monique , Sornay‐Rendu Elisabeth , Roux Jean‐paul , Delmas Pierre
Published: February 2009

Objective

To analyze a population‐based cohort of women in order to establish normal values of joint space width (JSW) and to evaluate the existence of age‐related joint space loss (JSL).

Methods

Knee radiographs were performed 4 years apart in women from the OFELY (Os des Femmes de Lyon) Cohort. Posteroanterior radiographs of both knees were taken in semiflexion with a standardized fluoroscopically assisted protocol. Radiographs were qualitatively evaluated using a scoring system based on the Altman score that assessed joint space narrowing, osteophytes, and sclerosis for each tibiofemoral compartment and each side. For quantitative assessment, radiographs were digitized using a video camera, and specific software was used to measure JSW in every compartment.

Results

We evaluated the radiographs of 606 women (ages 39–90 years, mean 62 years) and found that in all subjects, JSW significantly decreased with age in every compartment (r = −0.12 to −0.16, P < 0.001), including in 358 subjects without any radiographic abnormality related to osteoarthritis (OA) at baseline. The longitudinal analysis confirmed a significant loss over 4 years of ∼0.30 mm (6%) for the medial compartment. Multiple regression analysis did not identify significant predictors of JSL among clinical risk factors and biochemical markers of bone and cartilage turnover.

Conclusion

In this first longitudinal study of a population‐based cohort of women, we have established normal values of JSW and shown that JSW decreases with aging, especially at the medial compartment, even in subjects without any radiographic abnormalities related to OA.
Biomarkers of inflammation and development of rheumatoid arthritis in women from two prospective cohort studies
Authors: Karlson Elizabeth W. , Chibnik Lori B. , Tworoger Shelley S. , Lee I‐Min , Buring Julie E. , Shadick Nancy A. , Manson JoAnn E. , Costenbader Karen H.
Published: February 2009

Objective

To examine the association of biomarkers of inflammation with preclinical rheumatoid arthritis (RA).

Methods

A nested case–control study was performed using samples from 2 large, prospectively studied cohorts of women (the Women's Health Study [WHS] and the Nurses' Health Study [NHS]). Blood samples obtained prior to symptom onset in women who later developed RA were selected as incident RA cases, and 3 controls per case were randomly chosen, matched for age, menopausal status, postmenopausal hormone use, and day, time, and fasting status at the time of collection. Plasma was tested for levels of interleukin‐6 (IL‐6), soluble tumor necrosis factor receptor II (sTNFRII) (as a proxy for TNFα), and high‐sensitivity C‐reactive protein. Relationships between biomarkers and RA were assessed using conditional logistic regression models, adjusting for age, body mass index, smoking habits, ethnicity, and reproductive factors.

Results

In 93 incident cases in the NHS and 77 incident cases in the WHS, the mean time between blood collection and the onset of RA symptoms was 5.2 years (range 0.3–12 years). Median IL‐6 and sTNFRII levels were significantly higher in preclinical RA cases compared with matched controls in the NHS (P = 0.03 and P = 0.003, respectively) though not in the WHS. Pooled analysis of the NHS and WHS cohorts demonstrated significant association of sTNFRII with RA (relative risk 2.0 [95% confidence interval 1.1–3.6], P for trend = 0.004), and a modest association of IL‐6 with RA (relative risk 1.4 [95% confidence interval 0.8–2.5], P for trend = 0.06).

Conclusion

Levels of sTNFRII, a biomarker typically associated with active RA, were elevated up to 12 years prior to the development of RA symptoms and were positively associated with incident RA in these nested case–control studies. Studies with repeated assessments of biomarkers prior to RA development may provide further insight into the timing of biomarker elevation in preclinical RA.
Interleukin‐1β and tumor necrosis factor α inhibit chondrogenesis by human mesenchymal stem cells through NF‐κB–dependent pathways
Authors: Wehling N. , Palmer G. D. , Pilapil C. , Liu F. , Wells J. W. , Müller P. E. , Evans C. H. , Porter R. M.
Published: February 2009

Objective

The differentiation of mesenchymal stem cells (MSCs) into chondrocytes provides an attractive basis for the repair and regeneration of articular cartilage. Under clinical conditions, chondrogenesis will often need to occur in the presence of mediators of inflammation produced in response to injury or disease. The purpose of this study was to examine the effects of 2 important inflammatory cytokines, interleukin‐1β (IL‐1β) and tumor necrosis factor α (TNFα), on the chondrogenic behavior of human MSCs.

Methods

Aggregate cultures of MSCs recovered from the femoral intermedullary canal were used. Chondrogenesis was assessed by the expression of relevant transcripts by quantitative reverse transcription–polymerase chain reaction analysis and examination of aggregates by histologic and immunohistochemical analyses. The possible involvement of NF‐κB in mediating the effects of IL‐1β was examined by delivering a luciferase reporter construct and a dominant‐negative inhibitor of NF‐κB (suppressor‐repressor form of IκB [srIκB]) with adenovirus vectors.

Results

Both IL‐1β and TNFα inhibited chondrogenesis in a dose‐dependent manner. This was associated with a marked activation of NF‐κB. Delivery of srIκB abrogated the activation of NF‐κB and rescued the chondrogenic response. Although expression of type X collagen followed this pattern, other markers of hypertrophic differentiation responded differently. Matrix metalloproteinase 13 was induced by IL‐1β in a NF‐κB–dependent manner. Alkaline phosphatase activity, in contrast, was inhibited by IL‐1β regardless of srIκB delivery.

Conclusion

Cell‐based repair of lesions in articular cartilage will be compromised in inflamed joints. Strategies for enabling repair under these conditions include the use of specific antagonists of individual pyrogens, such as IL‐1β and TNFα, or the targeting of important intracellular mediators, such as NF‐κB.
The DERAA HLA–DR alleles in patients with early polyarthritis: Protection against severe disease and lack of association with rheumatoid arthritis autoantibodies
Authors: Carrier Nathalie , Cossette Pierre , Daniel Claude , de Brum‐Fernandes Artur , Liang Patrick , Ménard Henri A. , Boire Gilles
Published: February 2009

Objective

To define the association of alleles encoding the HLA–DR rheumatoid arthritis (RA) protective epitope (DERAA) with the presence of RA‐associated antibodies at study inclusion and with severe outcome in patients with early polyarthritis (EPA).

Methods

Consecutive EPA patients (n = 210) were evaluated early (mean of 4.8 months after diagnosis) and prospectively (for 30 months). HLA class II typing was performed by polymerase chain reaction using sequence‐specific primers, and HLA–DR alleles DERAA, RA‐associated shared epitope (SE), and non‐SE/non‐DERAA (neither SE nor DERAA) were identified. RA‐associated antibodies identified were anti‐Sa/citrullinated vimentin, anti–cyclic citrullinated peptide 2, and IgM rheumatoid factor. Severe disease was defined according to a preset threshold of joint destruction and/or functional limitation.

Results

DERAA and SE alleles were present in 62 and 110 of the 210 EPA patients, respectively. At 30 months, severe disease was present in 78 patients (37%). In contrast to SE alleles, DERAA alleles were not associated with the production of RA‐associated antibodies, but were strongly protective against severe disease at 30 months (odds ratio 0.30, P < 0.001). DERAA alleles emerged as a strong, independent protective marker on multivariate analysis. The protective effect of DERAA was seen only in patients who did not already have erosions at study inclusion, was independent of the presence of antibodies, but was not associated with spontaneous remission.

Conclusion

In our EPA cohort, the presence of a DERAA sequence was a strong independent predictor of a better prognosis, but only in the absence of erosive disease that was already present at inclusion. Identification of DERAA alleles may help in managing the large subgroup of EPA patients who do not have erosions at baseline.