1,674 research outputs found

    Leukocyte-specific protein 1 regulates T-cell migration in rheumatoid arthritis

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    Copy number variations (CNVs) have been implicated in human diseases. However, it remains unclear how they affect immune dysfunction and autoimmune diseases, including rheumatoid arthritis (RA). Here, we identified a novel leukocyte-specific protein 1 (LSP1) deletion variant for RA susceptibility located in 11p15.5. We replicated that the copy number of LSP1 gene is significantly lower in patients with RA, which correlates positively with LSP1 protein expression levels. Differentially expressed genes in Lsp1-deficient primary T cells represent cell motility and immune and cytokine responses. Functional assays demonstrated that LSP1, induced by T-cell receptor activation, negatively regulates T-cell migration by reducing ERK activation in vitro. In mice with T-cell-dependent chronic inflammation, loss of Lsp1 promotes migration of T cells into the target tissues as well as draining lymph nodes, exacerbating disease severity. Moreover, patients with RA show diminished expression of LSP1 in peripheral T cells with increased migratory capacity, suggesting that the defect in LSP1 signaling lowers the threshold for T-cell activation. To our knowledge, our work is the first to demonstrate how CNVs result in immune dysfunction and a disease phenotype. Particularly, our data highlight the importance of LSP1 CNVs and LSP1 insufficiency in the pathogenesis of RA and provide previously unidentified insights into the mechanisms underlying T-cell migration toward the inflamed synovium in RA.1187Ysciescopu

    Placental Growth Factor-1 and -2 Induce Hyperplasia and Invasiveness of Primary Rheumatoid Synoviocytes

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    Inflammation-mediated oncogenesis has been implicated in a variety of cancer types. Rheumatoid synovial tissues can be viewed as a tumor-like mass, consisting of hyperplastic fibroblast-like synoviocytes (FLSs). FLSs of rheumatoid arthritis (RA) patients have promigratory and invasive characteristics, which may be caused by chronic exposure to genotoxic stimuli, including hypoxia and growth factors. We tested whether a transformed phenotype of RA-FLSs is associated with placental growth factor (PlGF), a representative angiogenic growth factor induced by hypoxia. In this study, we identified PlGF-1 and PlGF-2 as the major PlGF isoforms in RA-FLSs. Global gene expression profiling revealed that cell proliferation, apoptosis, angiogenesis, and cell migration were mainly represented by differentially expressed genes in RA-FLSs transfected with small interfering RNA for PlGF. Indeed, PlGF-deficient RA-FLSs showed a decrease in cell proliferation, migration, and invasion, but an increase in apoptotic death in vitro. PlGF gene overexpression resulted in the opposite effects. Moreover, exogeneous PlGF-1 and PlGF-2 increased survival, migration, and invasiveness of RA-FLSs by binding their receptors, Flt-1 and neuropilin-1, and upregulating the expression of antiapoptotic molecules, pErk and Bcl2. Knockdown of PlGF transcripts reduced RA-FLS proliferation in a xenotransplantation model. Collectively, in addition to their role for neovascularization, PlGF-1 and -2 promote proliferation, survival, migration, and invasion of RA-FLSs in an autocrine and paracrine manner. These results demonstrated how primary cells of mesenchymal origin acquired an aggressive and transformed phenotype. PlGF and its receptors thus offer new targets for anti-FLS therapy.1177Ysciescopu

    Dll4 Suppresses Transcytosis for Arterial Blood-Retinal Barrier Homeostasis

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    Rationale: Central nervous system has low vascular permeability by organizing tight junction (TJ) and limiting endothelial transcytosis. While TJ has long been considered to be responsible for vascular barrier in central nervous system, suppressed transcytosis in endothelial cells is now emerging as a complementary mechanism. Whether transcytosis regulation is independent of TJ and its dysregulation dominantly causes diseases associated with edema remain elusive. Dll4 signaling is important for various vascular contexts, but its role in the maintenance of vascular barrier in central nervous system remains unknown. / Objective: To find a TJ-independent regulatory mechanism selective for transcytosis and identify its dysregulation as a cause of pathological leakage. / Methods and Results: We studied transcytosis in the adult mouse retina with low vascular permeability and employed a hypertension-induced retinal edema model for its pathological implication. Both antibody-based and genetic inactivation of Dll4 or Notch1 induce hyperpermeability by increasing transcytosis without junctional destabilization in arterial endothelial cells, leading to nonhemorrhagic leakage predominantly in the superficial retinal layer. Endothelial Sox17 deletion represses Dll4 in retinal arteries, phenocopying Dll4 blocking-driven vascular leakage. Ang II (angiotensin II)–induced hypertension represses arterial Sox17 and Dll4, followed by transcytosis-driven retinal edema, which is rescued by a gain of Notch activity. Transcriptomic profiling of retinal endothelial cells suggests that Dll4 blocking activates SREBP1 (sterol regulatory element-binding protein 1)-mediated lipogenic transcription and enriches gene sets favorable for caveolae formation. Profiling also predicts the activation of VEGF (vascular endothelial growth factor) signaling by Dll4 blockade. Inhibition of SREBP1 or VEGF-VEGFR2 (VEGF receptor 2) signaling attenuates both Dll4 blockade–driven and hypertension-induced retinal leakage. / Conclusions: In the retina, Sox17-Dll4-SREBP1 signaling axis controls transcytosis independently of TJ in superficial arteries among heterogeneous regulations for the whole vessels. Uncontrolled transcytosis via dysregulated Dll4 underlies pathological leakage in hypertensive retina and could be a therapeutic target for treating hypertension-associated retinal edema

    Sox7 promotes high-grade glioma by increasing VEGFR2-mediated vascular abnormality

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    High-grade glioma (HGG) is highly angiogenic, but antiangiogenic therapy has transient clinical benefit in only a fraction of patients. Vascular regulators of these heterogeneous responses remain undetermined. We found up-regulation of Sox7 and down-regulation of Sox17 in tumor endothelial cells (tECs) in mouse HGG.Sox7deletion suppressed VEGFR2 expression, vascular abnormality, hypoxia-driven invasion, regulatory T cell infiltration, and tumor growth. Conversely,Sox17deletion exacerbated these phenotypes by up-regulating Sox7 in tECs. Anti-VEGFR2 antibody treatment delayed tumor growth by normalizingSox17-deficient abnormal vessels with high Sox7 levels but promoted it by regressingSox7-deficient vessels, recapitulating variable therapeutic responses to antiangiogenic therapy in HGG patients. Our findings establish that Sox7 promotes tumor growth via vessel abnormalization, and its level determines the therapeutic outcome of VEGFR2 inhibition in HGG. In 189 HGG patients, Sox7 expression was heterogeneous in tumor vessels, and high Sox7 levels correlated with poor survival, early recurrence, and impaired vascular function, emphasizing the clinical relevance of Sox7 in HGG

    A pilot study to evaluate the effect of Taeumjowi-tang on obesity in Korean adults: study protocol for a randomised, double-blind, placebo-controlled, multicentre trial

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    <p>Abstract</p> <p>Background</p> <p>Obesity, which is described as excessive or abnormal body fat, increases the risk of diet-related diseases. In Korea and around the world, the prevalence of obesity has grown annually from 1998 to 2008. This growth has continued despite various therapeutic efforts. The discovery of new and alternative treatments for obesity should be considered an important priority. Taeumjowi-tang (TJ001), a traditional Korean medicinal extract consisting of eight herbs, is a widely used herbal remedy for obesity in Korea. However, the efficacy and safety of TJ001 have not been fully investigated in a clinical trial. The purpose of this pilot study is to estimate obesity-related parameters and to assess the efficacy and safety of TJ001.</p> <p>Methods</p> <p>Our study is a randomised, double-blind, placebo-controlled, multicentre clinical trial of Taeumjowi-tang (TJ001). For this study, we will recruit obese Korean patients of both sexes, ages 18 to 65 years, from four university hospitals. A total of 104 subjects will be recruited. The participants will receive either 7 g of TJ001 or a placebo three times daily for 12 weeks. The primary end point will be the rate of subjects who lose at least 5% of their baseline body weight. The secondary end points will be changes in body weight, body mass index, waist circumference, hip circumference, waist/hip circumference ratio, lipid profiles, body fat composition, blood pressure, fasting glucose concentration, C-reactive protein and questionnaires related to the quality of life. The outcomes will be measured every 4 weeks. The study period will be 12 weeks and will include a total of five visits with each subject (at screening and at 0, 4, 8 and 12 weeks).</p> <p>Conclusions</p> <p>The results of our study will inform various estimates of TJ001 and will serve as the basis for a larger-scale trial. This study will assess the efficacy and safety of TJ001 as an alternative herbal remedy for obesity.</p> <p>Trial registration</p> <p>Current Controlled Trials <a href="http://www.controlled-trials.com/ISRCTN87153759">ISRCTN87153759</a></p

    COVID-19 In Children Across Three Asian Cosmopolitan Regions

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    As another wave of COVID-19 outbreak has approached in July 2020, a larger scale COVID-19 pediatric Asian cohort summarizing the clinical observations is warranted. Children confirmed with COVID-19 infection from the Republic of Korea, the Hong Kong Special Administrative Region (HKSAR) and Wuhan, China, during their first waves of local outbreaks were included. Their clinical characteristics and the temporal sequences of the first waves of local paediatric outbreaks were compared. Four hundred and twenty three children with COVID-19 were analyzed. Wuhan had the earliest peak, followed by Korea and HKSAR. Compared with Korea and Wuhan, patients in HKSAR were significantly older (mean age: 12.9 vs. 10.8 vs. 6.6 years, p < 0.001, respectively) and had more imported cases (87.5% vs. 16.5% vs. 0%, p < 0.001, respectively). The imported cases were also older (13.4 vs. 7.6 years, p < 0.001). More cases in HKSAR were asymptomatic compared to Korea and Wuhan (45.5% vs. 22.0% vs. 20.9%, p < 0.001, respectively), and significantly more patients from Wuhan developed fever (40.6% vs. 29.7% vs. 21.6%, p=0.003, respectively). There were significantly less imported cases than domestic cases developing fever after adjusting for age and region of origin (p = 0.046). 5.4% to 10.8% of patients reported anosmia and ageusia. None developed pediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PMIS-TS). In general, adolescents were more likely to be asymptomatic and less likely to develop fever, but required longer hospital stays. In conclusion, majority patients in this pediatric Asian cohort had a mild disease. None developed PIMS-TS. Their clinical characteristics were influenced by travel history and age
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