pinecone/core-2020-05-10-deduplication huggingface dataset:
Intra-articular Injection of HB-IGF-1 Sustains Delivery of IGF-1 to Cartilage through Binding to Chondroitin Sulfate

Objective:
Insulin-like growth factor 1 (IGF-1) stimulates cartilage repair but is not a practical therapy due to its short half-life. We have previously modified IGF-1 by adding a heparin-binding domain and have shown that this fusion protein (HB-IGF-1) stimulates sustained proteoglycan synthesis in cartilage. This study was undertaken to examine the mechanism by which HB-IGF-1 is retained in cartilage and to test whether HB-IGF-1 provides sustained growth factor delivery to cartilage in vivo and to human cartilage explants.
Methods:
Retention of HB-IGF-1 and IGF-1 was analyzed by Western blotting. The necessity of heparan sulfate (HS) or chondroitin sulfate (CS) glycosaminoglycans (GAGs) for binding was tested using enzymatic removal and cells with genetic deficiency of HS. Binding affinities of HB-IGF-1 and IGF-1 proteins for isolated GAGs were examined by surface plasmon resonance and enzyme-linked immunosorbent assay.
Results:
In cartilage explants, chondroitinase treatment decreased binding of HB-IGF-1, whereas heparitinase had no effect. Furthermore, HS was not necessary for HB-IGF-1 retention on cell monolayers. Binding assays showed that HB-IGF-1 bound both CS and HS, whereas IGF-1 did not bind either. After intraarticular injection in rat knees, HB-IGF-1 was retained in articular and meniscal cartilage, but not in tendon, consistent with enhanced delivery to CS-rich cartilage. Finally, HB-IGF-1 was retained in human cartilage explants but IGF-1 was not.
Conclusion:
Our findings indicate that after intraarticular injection in rats, HB-IGF-1 is specifically retained in cartilage through its high abundance of CS. Modification of growth factors with heparin-binding domains may be a new strategy for sustained and specific local delivery to cartilage.National Institute of Biomedical Imaging and Bioengineering (U.S.) (Grant EB-003805)National Institute of Arthritis and Musculoskeletal and Skin Diseases (U.S.) (Grant AR-045779
Identification of novel genetic susceptibility loci in African American lupus patients in a candidate gene association study

Objective  Candidate gene and genome‐wide association studies have identified several disease susceptibility loci in lupus patients. These studies have largely been performed in lupus patients who are Asian or of European ancestry. This study was undertaken to examine whether some of these same susceptibility loci increase lupus risk in African American individuals.    Methods  Single‐nucleotide polymorphisms tagging 15 independent lupus susceptibility loci were genotyped in a set of 1,724 lupus patients and 2,024 healthy controls of African American descent. The loci examined included  PTPN22 ,  FCGR2A ,  TNFSF4 ,  STAT4 ,  CTLA4 ,  PDCD1 ,  PXK ,  BANK1 ,  MSH5  (HLA region),  CFB  (HLA region),  C8orf13‐BLK  region,  MBL2 ,  KIAA1542 ,  ITGAM , and  MECP2 / IRAK1 .    Results  We found the first evidence of genetic association between lupus in African American patients and 5 susceptibility loci ( C8orf13‐BLK ,  BANK1 ,  TNFSF4 ,  KIAA1542 , and  CTLA4 ;  P  = 8.0 × 10 −6 ,  P  = 1.9 × 10 −5 ,  P  = 5.7 × 10 −5 ,  P  = 0.00099, and  P  = 0.0045, respectively). Further, we confirmed the genetic association between lupus and 5 additional lupus susceptibility loci ( ITGAM ,  MSH5 ,  CFB ,  STAT4 , and  FCGR2A ;  P  = 7.5 × 10 −11 ,  P  = 5.2 × 10 −8 ,  P  = 8.7 × 10 −7 ,  P  = 0.0058, and  P  = 0.0070, respectively), and provided evidence, for the first time, of genome‐wide significance for the association between lupus in African American patients and  ITGAM  and  MSH5  (HLA region).    Conclusion  These findings provide evidence of novel genetic susceptibility loci for lupus in African Americans and demonstrate that the majority of lupus susceptibility loci examined confer lupus risk across multiple ethnicities
Blocking of interferon regulatory factor 1 reduces tumor necrosis factor α–induced interleukin‐18 bioactivity in rheumatoid arthritis synovial fibroblasts by induction of interleukin‐18 binding protein a: Role of the nuclear interferon regulatory factor 1–NF‐κB–c‐jun complex

Objective  To examine the role of interferon regulatory factor 1 (IRF‐1) in tumor necrosis factor α (TNFα)–induced interleukin‐18 binding protein a (IL‐18BPa) expression in rheumatoid arthritis synovial fibroblasts (RASFs).    Methods  TNFα‐induced IRF‐1 expression was assessed by real‐time quantitative polymerase chain reaction and Western blotting. The effect of TNFα on IRF‐1 was assessed using nuclear and cytoplasmic extracts, Western blots, and immunofluorescence. Chemical inhibitors of NF‐κB or MAP kinases were used to analyze the signaling pathways of TNFα‐induced IRF‐1 expression and IRF‐1 nuclear translocation. Control and IRF‐1 small interfering RNA (siRNA) were used to analyze the effect of IRF‐1 down‐regulation on TNFα‐induced IL‐18BP expression. IL‐18BPa expression was assessed by enzyme‐linked immunosorbent assay, and IL‐18 was assessed at the transcription and bioactivity levels using KG‐1 cells.    Results  TNFα induced RASF IRF‐1 expression at the messenger RNA and protein levels, with a maximal effect at 2 hours ( P  < 0.05; n ≥ 3). Furthermore, TNFα induced nuclear translocation of IRF‐1, with maximal translocation at 2 hours (∼6 fold‐induction) ( P  < 0.05; n = 4). Blocking of the NF‐κB or JNK‐2 pathways reduced TNFα‐induced IRF‐1 nuclear translocation by 35% and 50%, respectively ( P  < 0.05; n ≥ 4). Using siRNA to knock down IRF‐1, we observed reduced IL‐18BPa expression. Additionally, IL‐18 bioactivity was higher when siRNA was used to knock down IRF‐1 expression.    Conclusion  These results show that IRF‐1 is a key regulator of IL‐18BPa expression and IL‐18 bioactivity in RASFs. Regulation of IRF‐1 will be a new therapeutic target in RA
Reduced insular γ‐aminobutyric acid in fibromyalgia

Objective  Recent scientific findings have reinvigorated interest in examining the role of γ‐aminobutyric acid (GABA), the major inhibitory central nervous system neurotransmitter, in chronic pain conditions. Decreased inhibitory neurotransmission is a proposed mechanism in the pathophysiology of chronic pain syndromes such as fibromyalgia (FM). The purpose of this study was to test the hypothesis that decreased levels of insular and anterior cingulate GABA would be present in FM patients, and that the concentration of this neurotransmitter would be correlated with pressure–pain thresholds.    Methods  Sixteen FM patients and 17 age‐ and sex‐matched healthy controls underwent pressure–pain testing and a 3T proton magnetic resonance spectroscopy session in which the right anterior insula, right posterior insula, anterior cingulate, and occipital cortex were examined in subjects at rest.    Results  GABA levels in the right anterior insula were significantly lower in FM patients compared with healthy controls (mean ± SD 1.17 ± 0.24 arbitrary institutional units versus 1.42 ± 0.32 arbitrary institutional units;  P  = 0.016). There was a trend toward increased GABA levels in the anterior cingulate of FM patients compared with healthy controls ( P  = 0.06). No significant differences between groups were detected in the posterior insula or occipital cortex ( P  > 0.05 for all comparisons). Within the right posterior insula, higher levels of GABA were positively correlated with pressure–pain thresholds in the FM patients (Spearman's rho = 0.63;  P  = 0.02).    Conclusion  Diminished inhibitory neurotransmission resulting from lower concentrations of GABA within the right anterior insula may play a role in the pathophysiology of FM and other central pain syndromes
Evidence for gene–gene epistatic interactions among susceptibility loci for systemic lupus erythematosus

Objective  Several confirmed genetic susceptibility loci for lupus have been described. To date, no clear evidence for genetic epistasis in lupus has been established. The aim of this study was to test for gene–gene interactions in a number of known lupus susceptibility loci.    Methods  Eighteen single‐nucleotide polymorphisms tagging independent and confirmed lupus susceptibility loci were genotyped in a set of 4,248 patients with lupus and 3,818 normal healthy control subjects of European descent. Epistasis was tested by a 2‐step approach using both parametric and nonparametric methods. The false discovery rate (FDR) method was used to correct for multiple testing.    Results  We detected and confirmed gene–gene interactions between the HLA region and  CTLA4 ,  IRF5 , and  ITGAM  and between  PDCD1  and  IL21  in patients with lupus. The most significant interaction detected by parametric analysis was between rs3131379 in the HLA region and rs231775 in  CTLA4  (interaction odds ratio 1.19, Z = 3.95,  P  = 7.8 × 10 −5  [FDR ≤0.05],  P  for multifactor dimensionality reduction = 5.9 × 10 −45 ). Importantly, our data suggest that in patients with lupus, the presence of the HLA lupus risk alleles in rs1270942 and rs3131379 increases the odds of also carrying the lupus risk allele in  IRF5  (rs2070197) by 17% and 16%, respectively ( P  = 0.0028 and  P  = 0.0047, respectively).    Conclusion  We provide evidence for gene–gene epistasis in systemic lupus erythematosus. These findings support a role for genetic interaction contributing to the complexity of lupus heritability
Development of responder definitions for fibromyalgia clinical trials

Objective  To develop responder definitions for fibromyalgia (FM) clinical trials using key symptom and function domains.    Methods  Twenty‐four candidate responder definitions were developed by expert consensus and were evaluated in 12 randomized, placebo‐controlled trials of 4 medications for the treatment of FM. For each definition, the treatment effects of the medication compared with placebo were analyzed using Cochran‐Mantel‐Haenszel tests or chi‐square tests. A meta‐analysis of the pooled results for the 4 medications established risk ratios to determine the definitions that best favored medication over placebo.    Results  Two definitions performed best in the analyses. Both definitions included ≥30% reduction in pain and ≥10% improvement in physical function. The definitions differed in that one (≥30% improvement in FM [FM30] short version) included ≥30% improvement in sleep or fatigue, and the other (FM30 long version) required ≥30% improvement in 2 of the following symptoms: sleep, fatigue, depression, anxiety, or cognition. In the analysis of both versions, the response rate was ≥15% for each medication and was significantly greater compared with placebo. The risk ratio favoring drug over placebo in the pooled analysis for FM30 version 3 (short version) was 1.50 (95% confidence interval [95% CI] 1.24–1.82;  P  ≤ 0.0001); the risk ratio for FM30 version 6 (long version) was 1.60 (95% CI 1.31–1.96;  P  ≤ 0.00001).    Conclusion  Among the 24 responder definitions tested, 2 were identified as most sensitive in identifying response to treatment. The identification of responder definitions for FM clinical trials that include assessments of key symptom and function domains may improve the sensitivity of clinical trials to identify meaningful improvements, leading to improved management of FM
Interleukin-22 and interleukin-22-producing NKp44+ natural killer cells in subclinical gut inflammation in ankylosing spondylitis.

OBJECTIVE: \ud
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The intestinal inflammation observed in patients with ankylosing spondylitis (AS) is characterized by an overexpression of interleukin-23 (IL-23). IL-23 is known to regulate IL-22 production through lamina propria NKp44+ natural killer (NK) cells, which are thought to be involved in protective mucosal mechanisms. This study was undertaken to evaluate the frequency of NKp44+ NK cells and the expression of IL-22 in the ileum of AS patients.\ud
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METHODS: \ud
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Tissue NKp44+ NK cells, NKp46+ NK cells, and IL-22-producing cells were analyzed by flow cytometry. Quantitative gene expression analysis of IL-22, IL-23, IL-17, STAT-3, and mucin 1 (MUC-1) was performed by reverse transcriptase-polymerase chain reaction on ileal samples from 15 patients with AS, 15 patients with Crohn's disease (CD), and 15 healthy controls. NKp44, pSTAT-3, and IL-22 expression was analyzed by immunohistochemistry.\ud
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RESULTS: \ud
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The frequency of NKp44+ but not NKp46+ NK cells was increased in the inflamed ileum of AS patients compared to CD patients and controls. The frequency of NKp46+ NK cells was significantly increased only in CD patients. Among CD4+ lymphocytes and NKp44+ NK cell subsets, the latter were the major source of IL-22 on lamina propria mononuclear cells from AS patients. Significant up-regulation of IL-22, IL-23p19, MUC-1, and STAT-3 transcripts in the terminal ileum of patients with AS was observed. Immunohistochemical analysis confirmed the increased IL-22 and pSTAT-3 expression in inflamed mucosa from AS and CD patients.\ud
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CONCLUSION: \ud
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Our findings indicate that overexpression of IL-22, together with an increased number of IL-22-producing NKp44+ NK cells, occurs in the gut of AS patients, where it appears to play a tissue-protective role
Decreased intrinsic brain connectivity is associated with reduced clinical pain in fibromyalgia

Objective  A major impediment to the development of novel treatment strategies for fibromyalgia (FM) is the lack of an objective marker that reflects spontaneously reported clinical pain in patients with FM. Studies of resting‐state intrinsic brain connectivity in FM have demonstrated increased insular connectivity to the default mode network (DMN), a network whose activity is increased during nontask states. Moreover, increased insular connectivity to the DMN was associated with increased spontaneous pain levels. However, as these analyses were cross‐sectional in nature, they provided no insight into dynamic changes in connectivity or their relationship to variations in self‐reported clinical pain. The purpose of this study was to evaluate longitudinal changes in the intrinsic brain connectivity of FM patients treated with nonpharmacologic interventions known to modulate pain levels in this patient population, and to test the hypothesis that the reduction of DMN–insula connectivity following therapy would correlate with diminished pain.    Methods  Seventeen FM patients underwent resting‐state functional magnetic resonance imaging at baseline and following 4 weeks of a nonpharmacologic intervention to diminish pain. Intrinsic DMN connectivity was evaluated using probabilistic independent components analysis. Longitudinal changes in intrinsic DMN connectivity were evaluated by paired analysis, and correlations between longitudinal changes in clinical pain and changes in intrinsic DMN connectivity were investigated by multiple linear regression analysis. Changes in clinical pain were assessed with the short form of the McGill Pain Questionnaire (SF‐MPQ).    Results  Clinical pain as assessed using the sensory scale of the SF‐MPQ was reduced following therapy ( P  = 0.02). Intrinsic DMN connectivity to the insula was reduced, and this reduction correlated with reductions in pain (corrected  P  < 0.05).    Conclusion  Our findings suggest that intrinsic brain connectivity can be used as a candidate objective marker that reflects changes in spontaneous chronic pain within individual FM patients. We propose that intrinsic connectivity measures could potentially be used in either research or clinical settings as a complementary, more objective outcome measure for use in FM
Functional and genetic analyses of the MHC and its impact on autoimmunity in the rat

The major histocompatibility complex (MHC) is an allele-rich and exceptionally gene
dense region on human chromosome 6. Over 40% of the genes in this region have
immune-related functions, including genes encoding MHCI and MHCII molecules.
These molecules, which are found in nearly all vertebrates, present antigenic peptides to
CD4 and CD8 T cells. Alleles of MHCI and MHCII are believed to be strong risk factors
in autoimmune disorders, such as rheumatoid arthritis (RA), as well as in infectious
diseases. However, the differentiation between haplotype and allele associations in the
MHC is not straightforward. Strong linkage disequilibrium exists between gene
segments throughout the region and impedes identification of disease associated
variants. These gene segments can be isolated and studied individually in congenic mice
and rats. We produced for this thesis an extensive number of intra-MHC congenic rats
to study the association between MHC genes and experimental arthritis, T cell selection
and MHC regulation. Study I describes a genome-wide approach in heterogenous stock
rats to identify quantitative trait loci (QTLs) associated with variations in MHC levels
and CD4 and CD8 T cell numbers. A total of 10 QTLs were identified, of which 3
mapped to the MHC. We showed by congenic mapping that two minimal haplotypes of
~0.2 Mb explained the associations to the MHC. We further identified two allelic
variants of the gene Tap2 that contributed to the variation in T cell numbers. Study II
describes the effect of these minimal haplotypes on arthritis development and positions
the MHCII region for the first time in an adjuvant model. We show that genes in the
MHCII regulate onset, progression and severity of arthritis but not chronicity.
Comparative analyses of different congenic MHCII haplotypes showed an inverse
correlation between arthritis severity and proportion of recent thymic emigrants. Study
III shows an MHCII associated T cell response to the cartilage protein collagen type XI
in chronic pristane-induced arthritis (PIA) and the corresponding antibody response to
the same antigen in human RA. Study IV describes the adoptive transfer of PIA in DA
rats and outlines the conditions necessary for the model
Derivation and validation of the Systemic Lupus International Collaborating Clinics classification criteria for systemic lupus erythematosus.

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.The Systemic Lupus International Collaborating Clinics (SLICC) group revised and validated the American College of Rheumatology (ACR) systemic lupus erythematosus (SLE) classification criteria in order to improve clinical relevance, meet stringent methodology requirements, and incorporate new knowledge regarding the immunology of SLE.\ud
The classification criteria were derived from a set of 702 expert-rated patient scenarios. Recursive partitioning was used to derive an initial rule that was simplified and refined based on SLICC physician consensus. The SLICC group validated the classification criteria in a new validation sample of 690 new expert-rated patient scenarios.\ud
Seventeen criteria were identified. In the derivation set, the SLICC classification criteria resulted in fewer misclassifications compared with the current ACR classification criteria (49 versus 70; P = 0.0082) and had greater sensitivity (94% versus 86%; P < 0.0001) and equal specificity (92% versus 93%; P = 0.39). In the validation set, the SLICC classification criteria resulted in fewer misclassifications compared with the current ACR classification criteria (62 versus 74; P = 0.24) and had greater sensitivity (97% versus 83%; P < 0.0001) but lower specificity (84% versus 96%; P < 0.0001).\ud
The new SLICC classification criteria performed well in a large set of patient scenarios rated by experts. According to the SLICC rule for the classification of SLE, the patient must satisfy at least 4 criteria, including at least one clinical criterion and one immunologic criterion OR the patient must have biopsy-proven lupus nephritis in the presence of antinuclear antibodies or anti-double-stranded DNA antibodies
Protein kinase Cδ oxidation contributes to ERK inactivation in lupus T cells

Objective  CD4+ T cells from patients with active lupus have impaired ERK pathway signaling that decreases DNA methyltransferase expression, resulting in DNA demethylation, overexpression of immune genes, and autoimmunity. The ERK pathway defect is due to impaired phosphorylation of T 505  in the protein kinase Cδ (PKCδ) activation loop. However, the mechanisms that prevent PKCδ T 505  phosphorylation in lupus T cells are unknown. Others have reported that oxidative modifications, and nitration in particular, of T cells as well as serum proteins correlate with lupus disease activity. We undertook this study to test our hypothesis that nitration inactivates PKCδ, contributing to impaired ERK pathway signaling in lupus T cells.    Methods  CD4+ T cells were purified from lupus patients and controls and then stimulated with phorbol myristate acetate (PMA). Signaling protein levels, nitration, and phosphorylation were quantitated by immunoprecipitation and immunoblotting of T cell lysates. Transfections were performed by electroporation.    Results  Treating CD4+ T cells with peroxynitrite nitrated PKCδ, preventing PKCδ T 505  phosphorylation and inhibiting ERK pathway signaling similar to that observed in lupus T cells. Patients with active lupus had higher nitrated T cell PKCδ levels than did controls, which correlated directly with disease activity, and antinitrotyrosine immunoprecipitations demonstrated that nitrated PKCδ, but not unmodified PKCδ, was refractory to PMA‐stimulated T 505  phosphorylation, similar to PKCδ in peroxynitrite‐treated cells.    Conclusion  Oxidative stress causes PKCδ nitration, which prevents its phosphorylation and contributes to the decreased ERK signaling in lupus T cells. These results identify PKCδ as a link between oxidative stress and the T cell epigenetic modifications in lupus
Type I interferons modulate vascular function, repair, thrombosis, and plaque progression in murine models of lupus and atherosclerosis

Objective  Patients with systemic lupus erythematosus (SLE) have a notable increase in atherothrombotic cardiovascular disease (CVD) which is not explained by the Framingham risk equation. In vitro studies indicate that type I interferons (IFNs) may play prominent roles in increased CV risk in SLE. However, the in vivo relevance of these findings, with regard to the development of CVD, has not been characterized. This study was undertaken to examine the role of type I IFNs in endothelial dysfunction, aberrant vascular repair, and atherothrombosis in murine models of lupus and atherosclerosis.    Methods  Lupus‐prone New Zealand mixed 2328 (NZM) mice and atherosclerosis‐prone apolipoprotein E– knockout (apoE −/− ) mice were compared to mice lacking type I IFN receptor (INZM and apoE −/− IFNAR −/−  mice, respectively) with regard to endothelial vasodilatory function, endothelial progenitor cell (EPC) function, in vivo neoangiogenesis, plaque development, and occlusive thrombosis. Similar experiments were performed using NZM and apoE −/−  mice exposed to an IFNα‐containing or empty adenovirus.    Results  Loss of type I IFN receptor signaling improved endothelium‐dependent vasorelaxation, lipoprotein parameters, EPC numbers and function, and neoangiogenesis in lupus‐prone mice, independent of disease activity or sex. Further, acute exposure to IFNα impaired endothelial vasorelaxation and EPC function in lupus‐prone and non–lupus‐prone mice. Decreased atherosclerosis severity and arterial inflammatory infiltrates and increased neoangiogenesis were observed in apoE −/− IFNAR −/−  mice, compared to apoE −/−  mice, while NZM and apoE −/−  mice exposed to IFNα developed accelerated thrombosis and platelet activation.    Conclusion  These results support the hypothesis that type I IFNs play key roles in the development of premature CVD in SLE and, potentially, in the general population, through pleiotropic deleterious effects on the vasculature