bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synovial fluid mesenchymal stem cells in health and early osteoarthritis: Detection and functional evaluation at the single‐cell level
Authors: Jones Elena A. , Crawford Aileen , English Anne , Henshaw Karen , Mundy Jenifer , Corscadden Diane , Chapman Tony , Emery Paul , Hatton Paul , McGonagle Dennis 
Published: May 2008

AbstractObjectiveArthritic synovial fluid (SF) contains mesenchymal stem cells (MSCs), which could simply reflect their shedding from diseased joint structures. This study used the bovine model to explore SF MSCs in health and enumerated them at the earliest stages of human osteoarthritis (OA) in radiographically normal joints.MethodsClonogenicity and multipotentiality of normal bovine SF MSCs were compared with donor‐matched bone marrow (BM) MSCs at the single‐cell level. The colony‐forming unit–fibroblastic assay was used for MSC enumeration. The XTT assay was employed to assess cell proliferation, and flow cytometry was used to investigate the marker phenotype of bovine and human SF MSCs.ResultsSingle MSCs were present in normal bovine SF, and 96% of them were able to expand at least 1 million–fold. These cells were CD271–, multipotential, considerably more clonogenic, and less adipogenic than matched BM MSCs. In both pellet assays and on polyglycolic acid scaffolds, SF clones displayed consistent chondrogenic differentiation, while BM clones were variable. MSCs were present in arthroscopically normal human joints and were increased 7‐fold in early OA (P = 0.034). Their numbers correlated with numbers of free microscopic synovial tissue fragments (r = 0.826, P < 0.0001). OA SF had a growth‐promoting effect on synovial MSCs.ConclusionThis study confirms the presence of MSCs in normal SF and shows their numerical increase in early human OA. SF MSCs are likely to originate from synovium. These findings provide a platform for the exploration of the potential role of SF MSCs in joint homeostasis and for investigation of their utility in novel joint regeneration strategies.
Enhanced osteoclastogenesis in patients with tophaceous gout: Urate crystals promote osteoclast development through interactions with stromal cells
Authors: Dalbeth Nicola , Smith Timothy , Nicolson Bridget , Clark Barnaby , Callon Karen , Naot Dorit , Haskard Dorian O. , McQueen Fiona M. , Reid Ian R. , Cornish Jillian 
Published: May 2008

AbstractObjectiveTo analyze cellular mechanisms of bone erosion in gout.MethodsPeripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) from patients with gout were analyzed for the presence of osteoclast precursors. Fixed tophus and bone samples were analyzed by immunohistochemistry. Mechanisms of osteoclastogenesis were studied by culturing murine preosteoclast RAW 264.7 cells, bone marrow stromal ST2 cells, and human synovial fibroblasts with monosodium urate monohydrate (MSU) crystals.ResultsPBMCs from patients with severe erosive gout had the preferential ability to form osteoclast‐like cells in culture with RANKL and monocyte colony‐stimulating factor (M‐CSF). The number of PBMC‐derived tartrate‐resistant acid phosphatase (TRAP)–positive multinucleated cells strongly correlated with the number of tophi (r = 0.6296, P = 0.630). Patients with severe erosive and tophaceous gout also had higher circulating concentrations of RANKL and M‐CSF. Furthermore, greater numbers of TRAP‐positive multinucleated cells were cultured from SFMCs derived from gouty knee effusions than from paired PBMCs (P = 0.004). Immunohistochemical analysis demonstrated numerous multinucleated cells expressing osteoclast markers within tophi and at the interface between soft tissue and bone. MSU crystals did not directly promote osteoclast formation from RAW 264.7 cells in vitro. However, MSU crystals inhibited osteoprotegerin gene and protein expression in ST2 cells and human synovial fibroblasts, without significantly altering RANKL gene expression. Conditioned medium from ST2 cells cultured with MSU crystals promoted osteoclast formation from RAW 264.7 cells in the presence of RANKL.ConclusionChronic tophaceous and erosive gout is characterized by enhanced osteoclast development. These data provide a rationale for the study of osteoclast‐targeted therapies for the prevention of bone damage in chronic gout.
Dramatic regulation of heparanase activity and angiogenesis gene expression in synovium from patients with rheumatoid arthritis
Authors: Li Rachel W. , Freeman Craig , Yu Di , Hindmarsh Elizabeth J. , Tymms Kathleen E. , Parish Christopher R. , Smith Paul N. 
Published: May 2008

AbstractObjectiveAlthough heparanase is recognized as a proangiogenic factor, the involvement of heparanase in rheumatoid arthritis (RA) is unclear. In this study, we assessed heparanase activity in synovial fluid (SF) and synovial tissue (ST) from patients with RA or osteoarthritis (OA), and analyzed the expression of angiogenic pathway–focused genes in ST from RA and OA patients.MethodsSF and ST were obtained from the knees of patients with either RA or OA and from asymptomatic donors with no documented history of degenerative or inflammatory joint diseases. Heparanase activity was determined by an enzymatic assay using a radiolabeled substrate, and the presence of heparanase in ST was demonstrated by Western blotting. The expression of angiogenesis genes, including heparanase, in ST was analyzed by real‐time quantitative polymerase chain reaction.ResultsHeparanase activity was dramatically higher (>100‐fold) in SF and ST from RA patients than in SF and ST from OA patients and asymptomatic donors. Active heparanase enzyme was detected and heparanase messenger RNA was up‐regulated in ST from RA patients. We also found that angiogenesis gene expression was significantly regulated in RA synovium, and was correlated with heparanase activity.ConclusionThese findings are novel and contribute to our understanding of joint destruction in RA, suggesting that heparanase may be a reliable prognostic factor for RA progression and an attractive target for the treatment of RA.
Age at onset–dependent presentations of premature hip osteoarthritis, avascular necrosis of the femoral head, or Legg‐Calvé‐Perthes disease in a single family, consequent upon a p.Gly1170Ser mutation of COL2A1
Authors: Su Peiqiang , Li Ru , Liu Shangli , Zhou Yan , Wang Xinguang , Patil Nilesh , Mow Christopher S. , Mason Justin C. , Huang Dongsheng , Wang Yiming 
Published: May 2008

AbstractObjectiveTo identify the genetic abnormality responsible for osteoarthritis (OA), avascular necrosis (AVN) of the femoral head, and Legg‐Calvé‐Perthes disease in a single family, and to determine factors responsible for the distinct phenotypes manifested by different family members.MethodsForty‐two members of a 5‐generation family were recruited and investigated. Diagnosis was made by independent orthopedic surgeons and radiologists. Histopathologic changes of the diseased tissue were examined. Linkage analysis was performed with markers spanning the COL2A1 locus. Haplotypes were constructed and mutation of the gene was detected. Structures of the wild‐type and mutant proteins were modeled.ResultsSixteen affected members were identified (5 with isolated precocious hip OA, 6 with AVN of the femoral head, and 5 with Legg‐Calvé‐Perthes disease). A p.Gly1170Ser mutation of COL2A1 cosegregated with the 3 diseases and was absent in controls. Of note, age at onset in relation to the closure status of the femoral head epiphysis was associated with the diseases, with Legg‐Calvé‐Perthes disease presenting prior to closure (at ages 6–14 years), AVN of the femoral head presenting during closure (at ages 15–18 years), and precocious OA of the hip presenting after closure (at ages 21–34 years). Molecular modeling predicted that the serine‐to‐glycine substitution loosens the helical structure of the protein.ConclusionThe p.Gly1170Ser mutation of COL2A1 in the family described is responsible for pathology confined to the hip joint, which presents as isolated precocious hip OA, AVN of the femoral head, or Legg‐Calvé‐Perthes disease. Age at onset in relation to closure of the femoral head epiphysis appears to be a critical factor in determining disease pattern.
Decreased lubricin concentrations and markers of joint inflammation in the synovial fluid of patients with anterior cruciate ligament injury
Authors: Elsaid K. A. , Fleming B. C. , Oksendahl H. L. , Machan J. T. , Fadale P. D. , Hulstyn M. J. , Shalvoy R. , Jay G. D. 
Published: May 2008

AbstractObjectiveTo study the effect of anterior cruciate ligament (ACL) injury on lubricin concentrations in synovial fluid (SF) and its correlation with time postinjury, inflammatory cytokines, lubricin‐degrading enzymes, and SF proteoglycan content.MethodsSF samples were obtained from both knees of 30 patients with unilateral ACL insufficiency, 32–364 days postinjury. Lubricin, inflammatory cytokines (interleukin‐1β [IL‐1β], tumor necrosis factor α [TNFα], and IL‐6), and catabolic enzymes (procathepsin B and neutrophil elastase) were measured in SF from injured and contralateral (uninjured) joints, by enzyme‐linked immunosorbent assay. Sulfated glycosaminoglycan (sGAG) levels in the SF were measured by Alcian blue binding assay.ResultsSF lubricin concentrations were significantly (P < 0.001) reduced at an early stage following ACL injury when compared with those in the contralateral joint. Within 12 months, the lubricin concentration in the injured knee (slope = 0.006, SE = 0.00010, P < 0.001) approached that in the contralateral knee, which did not change with time (slope = −0.0002, SE = 0.00050, P = 0.71). TNFα levels showed a significant negative relationship with log2 lubricin levels. IL‐1β, TNFα, IL‐6, procathepsin B, and neutrophil elastase concentrations in SF from injured knees were greater in samples from recently injured knees compared with those that were chronically injured. There were no detectable cytokines or enzymes in the SF of contralateral joints. Concentrations of sGAG were significantly (P = 0.0002) higher in the SF from injured knees compared with the contralateral joints.ConclusionThe decrease in SF lubricin concentrations following ACL injury may place the joint at an increased risk of wear‐induced damage as a consequence of lack of boundary lubrication, potentially leading to secondary osteoarthritis. The decrease in SF lubricin was associated with an increase in levels of inflammatory cytokines.
Functionally relevant variations of the interleukin‐10 gene associated with antineutrophil cytoplasmic antibody–negative Churg‐Strauss syndrome, but not with Wegener's granulomatosis
Authors: Wieczorek S. , Hellmich B. , Arning L. , Moosig F. , Lamprecht P. , Gross W. L. , Epplen J. T. 
Published: May 2008

AbstractObjectiveWegener's granulomatosis (WG) and Churg‐Strauss syndrome (CSS) belong to the heterogeneous group of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitides. Current understanding of their pathogenesis and genetic background is limited. Expression levels of interleukin‐10 (IL‐10), a potent and pleiotropic cytokine, are largely determined by variations in the gene encoding the IL‐10 precursor. This study was undertaken to determine the impact of IL10 polymorphisms on the pathogenesis of both WG and CSS in large cohorts.MethodsThree single‐nucleotide polymorphisms (SNPs) tagging the promoter haplotypes of the IL10 gene (IL10 −3575, IL10 −1082, and IL10 −592) were analyzed in 403 patients with WG and 103 patients with CSS as well as 507 matched control subjects from Germany. In addition, 3 informative SNPs in other parts of IL10 were genotyped.ResultsNone of the markers or their haplotypes was associated with WG or any of its subgroups classified according to ANCA status, sex, or presence of further WG genetic risk factors. In contrast, the IL10 −3575/−1082/−592 TAC haplotype, part of the extended ancient haplotype IL10.2, was highly significantly associated with ANCA‐negative CSS (χ2 = 19.14, P = 0.000012, corrected P = 0.0003, odds ratio 2.16, 95% confidence interval 1.52–3.06).ConclusionThese findings challenge those from previous studies of IL10 in WG and provide further evidence that CSS and WG have distinct genetic backgrounds. Because the IL10.2 haplotype has been correlated reproducibly with increased IL10 expression, the possible role of IL‐10 in the pathogenesis of ANCA‐negative CSS needs to be further elucidated.
Cytokines secreted in response to Toll‐like receptor ligand stimulation modulate differentiation of human Th17 cells
Authors: Kattah Michael G. , Wong Michael T. , Yocum Matthew D. , Utz Paul J. 
Published: May 2008

AbstractObjectiveTh17 cells (interleukin‐17 [IL‐17]–secreting T helper cells) have been implicated in the pathogenesis of rheumatoid arthritis and other autoimmune diseases, but the soluble factors that influence human Th17 differentiation have yet to be fully elucidated. This study was undertaken to investigate the hypothesis that the cytokines secreted by human peripheral blood mononuclear cells (PBMCs) in response to a subset of Toll‐like receptor (TLR) ligands would influence Th17 polarization.MethodsSupernatants from human PBMCs treated with a panel of TLR agonists were tested for their ability to induce de novo IL‐17 production in naive T helper cells. Multiplex cytokine analysis was used to identify candidate cytokines for subsequent blocking and sufficiency experiments.ResultsConditioned media from PBMCs stimulated with TLR‐4 or TLR‐8/7 agonists, but not from those stimulated with TLR‐2/1, ‐3, or ‐9 agonists, evoked robust secretion of IL‐17 by T helper cells, independent of coculture with antigen‐presenting cells. Multiplex analysis of 22 cytokines and chemokines identified a 6‐factor cytokine signature that significantly correlated with IL‐17–inducing activity. T cell activation in the presence of recombinant IL‐1β, IL‐6, and IL‐23 reconstituted robust IL‐17 production, and this was enhanced by transforming growth factor β (TGFβ). IL‐6 suppressed the expression of forkhead box P3 and reversed TGFβ‐mediated inhibition of T cell proliferation, but did not trigger IL‐17 secretion. IL‐17 production was completely abrogated by anti–IL‐1 or IL‐1 receptor antagonist and partially inhibited by anti–IL‐6, anti–IL‐2, or exogenous retinoic acid, but not by anti–tumor necrosis factor α. IL‐1β and IL‐6 independently induced IL‐21 secretion, but the presence of IL‐21 alone was not sufficient for IL‐17 production.ConclusionThese results indicate that ligation of a subset of TLRs generates proinflammatory cytokines that combine to potentiate human Th17 differentiation.
Activated memory B cell subsets correlate with disease activity in systemic lupus erythematosus: Delineation by expression of CD27, IgD, and CD95
Authors: Jacobi Annett M. , Reiter Karin , Mackay Meggan , Aranow Cynthia , Hiepe Falk , Radbruch Andreas , Hansen Arne , Burmester Gerd‐R. , Diamond Betty , Lipsky Peter E. , Dörner Thomas 
Published: May 2008

AbstractObjectiveAnalysis of peripheral B cell subsets in patients with systemic lupus erythematosus (SLE) has provided evidence of specific alterations, such as an expansion of CD27++ plasma cells/blasts and transitional B cells. However, memory B cells in lupus have not been thoroughly investigated, and only recently a CD27− memory B cell subset was identified in the peripheral blood of lupus patients. Focusing on CD27− B cells, this study aimed to identify abnormalities in peripheral B cell subsets in patients with SLE.MethodsThree independent cohorts of lupus patients were used to characterize CD27− memory B cells, using multiparameter flow cytometry and single‐cell reverse transcription–polymerase chain reaction of heavy‐chain transcripts.ResultsWe identified a homogeneous subset of CD27−,IgD−,CD95+ memory B cells with an activated phenotype that was increased in patients with disease flares and that correlated with disease activity and serologic abnormalities. In contrast, the entire subset of CD27−,IgD− B cells was found to be heterogeneous, did not correlate significantly with lupus activity, and was also increased in patients with bacterial infections.ConclusionWe conclude that CD95 is a useful marker to identify CD27− memory B cells with an activated phenotype, which might serve as a biomarker for lupus activity and as a target of further investigations aiming to elucidate the pathogenic potential of these cells and the mechanisms involved in the generation as well as regulation of this CD27−,IgD−,CD95+ memory B cell subset.
Aromatase expression in osteoarthritic and osteoporotic bone
Authors: Hernández José L. , Garcés Carlos M. , Sumillera Manuel , Fernández‐Aldasoro Eugenio V. , García‐Ibarbia Carmen , Ortiz‐Gómez Jesús A. , Arozamena Jana , Alonso María A. , Riancho José A. 
Published: May 2008

AbstractObjectiveEstrogen deprivation is a central mechanism in the development of osteoporosis with aging. Results from recent studies also suggest the involvement of estrogens in the pathophysiology of osteoarthritis (OA). Aromatization of androgenic precursors in peripheral tissue is the main source of estrogens in postmenopausal women and in men. However, the importance of aromatase expression in bone is a subject of controversy. This study was undertaken to determine aromatase expression in bone samples from patients with hip fracture and patients with OA.MethodsWe studied 104 patients with hip fracture (n = 60) or primary hip OA (n = 44). Aromatase expression was determined in trabecular bone samples from the femoral neck and in osteoblast cultures grown by the primary explant technique (n = 62), using real‐time reverse transcriptase–polymerase chain reaction.ResultsAromatase RNA was detected in bone samples at levels similar to those found in adipose tissue. Transcript levels were significantly lower in bone tissue samples obtained from patients with OA than in those obtained from patients with fracture (P = 0.00001). Likewise, primary cultures of osteoblast cells from OA patients revealed lower aromatase expression than those of cells from fracture patients (P = 0.012). Results were independent of age or sex differences.ConclusionOur findings indicate that the aromatase gene is expressed in bone tissue in high amounts, similar to those found in adipose tissue, but transcript levels are lower in tissue samples and osteoblast cultures from patients with OA than in those from patients with hip fracture. Since estrogens may help to prevent local cartilage degradation, it can be speculated that such a reduced expression of aromatase could facilitate the development of OA.
A multicenter, randomized, double‐blind, placebo‐controlled trial of oral type I collagen treatment in patients with diffuse cutaneous systemic sclerosis: I. Oral type I collagen does not improve skin in all patients, but may improve skin in late‐phase disease
Authors: Postlethwaite Arnold E. , Wong Weng Kee , Clements Philip , Chatterjee Soumya , Fessler Barri J. , Kang Andrew H. , Korn Joseph , Mayes Maureen , Merkel Peter A. , Molitor Jerry A. , Moreland Larry , Rothfield Naomi , Simms Robert W. , Smith Edwin A. , Spiera Robert , Steen Virginia , Warrington Kenneth , White Barbara , Wigley Frederick , Furst Daniel E. 
Published: May 2008

AbstractObjectiveTo investigate the safety and efficacy of oral bovine type I collagen (CI) treatment in patients who have had diffuse cutaneous systemic sclerosis (dcSSc; scleroderma) for ≤10 years.MethodsOne hundred sixty‐eight patients with dcSSc were enrolled in a double‐blind, placebo‐controlled trial of oral CI (500 μg/day) or placebo administered over 12 months, with a followup visit at month 15. The primary outcome was the modified Rodnan skin thickness score (MRSS). Other clinical and immune system parameters were also assessed.ResultsIntent‐to‐treat and modified intent‐to‐treat analyses showed that for the total population of patients with dcSSc, there were no significant differences in the mean change in MRSS or other key clinical parameters between the CI and placebo treatment groups at 12 months or at 15 months. However, in a subanalysis of the available data at month 15, the CI‐treated group of patients with late‐phase dcSSc experienced a significant reduction in the MRSS compared with that in the placebo‐treated patients with late‐phase dcSSc (change in MRSS at month 15 −7.9 versus −2.9; P = 0.0063).ConclusionAlthough the results from this trial did not meet the primary outcome goals, the findings from exploratory analyses indicated that CI treatment may benefit patients with late‐phase dcSSc. This new treatment strategy and preliminary clinical observations in patients with dcSSc need to be corroborated.
The rheumatoid arthritis–associated allele HLA–DR10 (DRB1*1001) shares part of its repertoire with HLA–DR1 (DRB1*0101) and HLA–DR4 (DRB*0401)
Authors: Alvarez Iñaki , Collado Javier , Daura Xavier , Colomé Nuria , Rodríguez‐García Marta , Gallart Teresa , Canals Francesc , Jaraquemada Dolores 
Published: May 2008

AbstractObjectiveTo identify the peptide anchor motif for the rheumatoid arthritis (RA)–related HLA allele, DR10, and find shared natural ligands or sequence similarities with the other disease‐associated alleles, DR1 and DR4.MethodsThe HLA–DR10–associated peptides were purified, and a proportion of these natural ligands were de novo sequenced by mass spectrometry. Based on crystallographic structures, the complexes formed by peptide influenza virus hemagglutinin HA306–318 with DR1, DR4, and DR10 were modeled, and binding scores were obtained.ResultsA total of 238 peptides were sequenced, and the anchor motif of the HLA–DR10 peptide repertoire was defined. A large proportion of the DR10‐associated peptides had the structural features to bind DR1 and DR4 but were theoretical nonbinders to the negatively associated alleles DR15 and DR7. Among the sequenced ligands, 10 had been reported as ligands to other RA‐associated alleles. Modeling data showed that peptide HA306–318 can bind DR1, DR4, and DR10 with similar affinities.ConclusionThe data show the presence of common peptides in the repertoires of RA‐associated HLA alleles. The combination of the shared epitope present in DR1, DR4, and DR10 together with common putative arthritogenic peptide(s) could influence disease onset or outcome.