223 research outputs found

    Effects of Continuous Positive Airway Pressure on White Matter Microstructure in Patients With Obstructive Sleep Apnea

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    Background and Objective Obstructive sleep apnea (OSA) has significant effects on quality of life and may lead to cognitive impairments. Continuous positive airway pressure (CPAP) is the standard treatment for OSA and has been shown to improve sleep disturbances and daytime dysfunction. In this study, we aimed to assess the effects of CPAP on white matter (WM) integrity using longitudinal diffusion tensor imaging (DTI) tests. Methods Twenty-two male patients with moderate to severe OSA were recruited, and thepatients underwent DTI scanning before and 6–44 months after CPAP treatment. Sixteen male patients with untreated OSA who were not compliant with CPAP were included as a reference group. We compared the functional anisotropy (FA) values between baseline and follow-up magnetic resonance imaging in both the CPAP and untreated groups using tract-specific statistical analysis (TSSA) method. Results The TSSA analysis showed that FA values in the middle part of the right corticospinal tract were increased after treatment in the CPAP group. In the untreated group, no significant change in FA value was observed between baseline and follow-up. In the CPAP group, the post-treatment FA value in the anterior part of the right anterior thalamic radiation was significantly correlated with the duration of CPAP therapy, after controlling for age, body mass index, and baseline FA value. Conclusions Our study suggests that long-term CPAP treatment could gradually reverse OSA-induced injury to the WM microstructure, particularly WM associated with the motor and limbic systems. The study findings provide new insights into the mechanisms of cognitive improvement after CPAP treatment in patients with OSA

    FBXW7-mediated ERK3 degradation regulates the proliferation of lung cancer cells

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    Extracellular signal-regulated kinase 3 (ERK3) is an atypical member of the mitogen-activated protein kinase (MAPK) family, members of which play essential roles in diverse cellular processes during carcinogenesis, including cell proliferation, differentiation, migration, and invasion. Unlike other MAPKs, ERK3 is an unstable protein with a short half-life. Although deubiquitination of ERK3 has been suggested to regulate the activity, its ubiquitination has not been described in the literature. Here, we report that FBXW7 (F-box and WD repeat domain-containing 7) acts as a ubiquitination E3 ligase for ERK3. Mammalian two-hybrid assay and immunoprecipitation results demonstrated that ERK3 is a novel binding partner of FBXW7. Furthermore, complex formation between ERK3 and the S-phase kinase-associated protein 1 (SKP1)-cullin 1-F-box protein (SCF) E3 ligase resulted in the destabilization of ERK3 via a ubiquitination-mediated proteasomal degradation pathway, and FBXW7 depletion restored ERK3 protein levels by inhibiting this ubiquitination. The interaction between ERK3 and FBXW7 was driven by binding between the C34D of ERK3, especially at Thr417 and Thr421, and the WD40 domain of FBXW7. A double mutant of ERK3 (Thr417 and Thr421 to alanine) abrogated FBXW7-mediated ubiquitination. Importantly, ERK3 knockdown inhibited the proliferation of lung cancer cells by regulating the G1/S-phase transition of the cell cycle. These results show that FBXW7-mediated ERK3 destabilization suppresses lung cancer cell proliferation in vitro

    Clinical implications of gut microbiota and cytokine responses in coronavirus disease prognosis

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    ObjectivesSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects gut luminal cells through the angiotensin-converting enzyme-2 receptor and disrupts the gut microbiome. We investigated whether the gut microbiome in the early stage of SARS-CoV-2 infection was associated with the prognosis of coronavirus disease (COVID-19).MethodsThirty COVID-19 patients and 16 healthy controls were prospectively enrolled. Blood and stool samples and clinical details were collected on days 0 (enrollment), 7, 14, and 28. Participants were categorized into four groups by their clinical course.ResultsGut microbiota composition varied during the clinical course of COVID-19 and was closely associated with cytokine levels (p=0.003). A high abundance of the genus Dialister (linear discriminant analysis [LDA] effect size: 3.97856, p=0.004), species Peptoniphilus lacrimalis (LDA effect size: 4.00551, p=0.020), and Anaerococcus prevotii (LDA effect size: 4.00885, p=0.007) was associated with a good prognosis. Starch, sucrose, and galactose metabolism was highly activated in the gut microbiota of the poor prognosis group. Glucose-lowering diets, including whole grains, were positively correlated with a good prognosis.ConclusionGut microbiota may mediate the prognosis of COVID-19 by regulating cytokine responses and controlling glucose metabolism, which is implicated in the host immune response to SARS-CoV-2

    Fargesin Inhibits EGF-Induced Cell Transformation and Colon Cancer Cell Growth by Suppression of CDK2/Cyclin E Signaling Pathway

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    Although the lignan compound fargesin is a major ingredient in Shin-Yi, the roles of fargesin in carcinogenesis and cancer cell growth have not been elucidated. In this study, we observed that fargesin inhibited cell proliferation and transformation by suppression of epidermal growth factor (EGF)-stimulated G1/S-phase cell cycle transition in premalignant JB6 Cl41 and HaCaT cells. Unexpectedly, we found that signaling pathway analyses showed different regulation patterns in which fargesin inhibited phosphatidylinositol 3-kinase/AKT signaling without an alteration of or increase in mitogen activated protein kinase (MAPK) in JB6 Cl41 and HaCaT cells, while both signaling pathways were abrogated by fargesin treatment in colon cancer cells. We further found that fargesin-induced colony growth inhibition of colon cancer cells was mediated by suppression of the cyclin dependent kinase 2 (CDK2)/cyclin E signaling axis by upregulation of p21WAF1/Cip1, resulting in G1-phase cell cycle accumulation in a dose-dependent manner. Simultaneously, the suppression of CDK2/cyclin E and induction of p21WAF1/Cip1 were correlated with Rb phosphorylation and c-Myc suppression. Taken together, we conclude that fargesin-mediated c-Myc suppression inhibits EGF-induced cell transformation and colon cancer cell colony growth by the suppression of retinoblastoma (Rb)-E2F and CDK/cyclin signaling pathways, which are mainly regulated by MAPK and PKB signaling pathways

    Causes and effects of 2008 financial crisis

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    Beginning in the mid 2007’s the US financial market started to slide into the “worst financial crisis since the Great Depression of the early 1930’s” (Thakor, 2015: p.156). The domino effect of several events and occasions were leading first to a countrywide recession in the USA then later spreading globally. In the following this term paper will deal with the main causes and effects of 2008 financial crisis. Unlike other topics in literature there is no consensus about the question of guilt in this sense. Among economists there are different approaches to explain the main causes of the financial crisis

    A Synonymous Genetic Alteration of LMX1B in a Family with Nail-Patella Syndrome

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    The gene responsible for nail-patella syndrome, LMX1B, has recently been identified on chromosome 9q. Here we present a patient with nail-patella syndrome and an autosomal dominant pattern of inheritance. A 17-year-old girl visited our clinic for the evaluation and treatment of proteinuria. She had dystrophic nails, palpable iliac horns, and hypoplastic patellae. Electron microscopy of a renal biopsy showed irregular thickening of the glomerular basement membrane. A family history over three generations revealed five affected family members. Genetic analysis found a change of TCG to TCC, resulting in a synonymous alteration at codon 219 in exon 4 of the LMX1B gene in two affected family members. The same alteration was not detected in an unaffected family member. This is the first report of familial nail-patella syndrome associated with an LMX1B in Korea mutation, However, we can not completely rule out the possibility that the G-to-C change may be a single nucleotide polymorphism as this genetic mutation cause no alteration in amino acid sequence of LMX1B

    RSK2-Mediated ELK3 Activation Enhances Cell Transformation and Breast Cancer Cell Growth by Regulation of c-fos Promoter Activity

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    Ribosomal S6 kinase 2 (RSK2), regulated by Ras/Raf/MEKs/ERKs, transmits upstream activation signals to downstream substrates including kinases and transcription and epigenetic factors. We observed that ELK members, including ELK1, 3, and 4, highly interacted with RSK2. We further observed that the RSK2-ELK3 interaction was mediated by N-terminal kinase and linker domains of RSK2, and the D and C domains of ELK3, resulting in the phosphorylation of ELK3. Importantly, RSK2-mediated ELK3 enhanced c-fos promoter activity. Notably, chemical inhibition of RSK2 signaling using kaempferol (a RSK2 inhibitor) or U0126 (a selective MEK inhibitor) suppressed EGF-induced c-fos promoter activity. Moreover, functional deletion of RSK2 by knockdown or knockout showed that RSK2 deficiency suppressed EGF-induced c-fos promoter activity, resulting in inhibition of AP-1 transactivation activity and Ras-mediated foci formation in NIH3T3 cells. Immunocytofluorescence assay demonstrated that RSK2 deficiency reduced ELK3 localization in the nucleus. In MDA-MB-231 breast cancer cells, knockdown of RSK2 or ELK3 suppressed cell proliferation with accumulation at the G1 cell cycle phase, resulting in inhibition of foci formation and anchorage-independent cancer colony growth in soft agar. Taken together, these results indicate that a novel RSK2/ELK3 signaling axis, by enhancing c-Fos-mediated AP-1 transactivation activity, has an essential role in cancer cell proliferation and colony growth
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