83 research outputs found

    1,25-Dihydroxyvitamin D3 Inhibits the Differentiation and Migration of TH17 Cells to Protect against Experimental Autoimmune Encephalomyelitis

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    BACKGROUND: Vitamin D(3), the most physiologically relevant form of vitamin D, is an essential organic compound that has been shown to have a crucial effect on the immune responses. Vitamin D(3) ameliorates the onset of the experimental autoimmune encephalomyelitis (EAE); however, the direct effect of vitamin D(3) on T cells is largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: In an in vitro system using cells from mice, the active form of vitamin D(3) (1,25-dihydroxyvitamin D(3)) suppresses both interleukin (IL)-17-producing T cells (T(H)17) and regulatory T cells (Treg) differentiation via a vitamin D receptor signal. The ability of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) to reduce the amount of IL-2 regulates the generation of Treg cells, but not T(H)17 cells. Under T(H)17-polarizing conditions, 1,25(OH)(2)D(3) helps to increase the numbers of IL-10-producing T cells, but 1,25(OH)(2)D(3)'s negative regulation of T(H)17 development is still defined in the IL-10(-/-) T cells. Although the STAT1 signal reciprocally affects the secretion of IL-10 and IL-17, 1,25(OH)(2)D(3) inhibits IL-17 production in STAT1(-/-) T cells. Most interestingly, 1,25(OH)(2)D(3) negatively regulates CCR6 expression which might be essential for T(H)17 cells to enter the central nervous system and initiate EAE. CONCLUSIONS/SIGNIFICANCE: Our present results in an experimental murine model suggest that 1,25(OH)(2)D(3) can directly regulate T cell differentiation and could be applied in preventive and therapeutic strategies for T(H)17-mediated autoimmune diseases

    The positive feedback loop between Nrf2 and phosphogluconate dehydrogenase stimulates proliferation and clonogenicity of human hepatoma cells

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    Β© 2020, Β© 2020 Informa UK Limited, trading as Taylor & Francis Group.Recent studies report that nuclear factor-erythroid-2-related factor 2 (Nrf2) facilitates tumor progression through metabolic reprogramming in cancer cells. However, the molecular mechanism underlying the oncogenic functions of Nrf2 is not yet well understood. Some of the pentose phosphate pathway (PPP) enzymes are considered to play a role in the cancer progression. The present study was intended to explore the potential role of phosphogluconate dehydrogenase (PGD), one of the PPP enzymes, in the proliferation and migration of human hepatoma HepG2 cells. Genetic ablation of Nrf2 attenuated the expression of PGD at both transcriptional and translational levels. Notably, Nrf2 regulates the transcription of PGD through direct binding to the antioxidant response element in its promoter region. Nrf2 overexpression in HepG2 cells led to increased proliferation, survival, and migration, and these events were suppressed by silencing PGD. Interestingly, knockdown of the gene encoding this enzyme not only attenuated the proliferation and clonogenicity of HepG2 cells but also downregulated the expression of Nrf2. Thus, there seems to exist a positive feedback loop between Nrf2 and PGD which is exploited by hepatoma cells for their proliferation and survival. Treatment of HepG2 cells with ribulose-5-phosphate, a catalytic product of PGD, gave rise to a concentration-dependent upregulation of Nrf2. Collectively, the current study shows that Nrf2 promotes hepatoma cell growth and progression, partly through induction of PGD transcription.

    Hemophagocytic Syndrome in a Patient with Acute Tubulointerstitial Nephritis Secondary to Hepatitis A Virus Infection

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    Hepatitis A virus (HAV) infection is generally a self-limited disease, but the infection in adults can be serious, to be often complicated by acute kidney injury (AKI) and rarely by virus-associated hemophagocytic syndrome (VAHS). Our patient, a 48-yr-old man, was diagnosed with HAV infection complicated by dialysis-dependent AKI. His kidney biopsy showed acute tubulointerstitial nephritis with massive infiltration of activated macrophages and T cells, and he progressively demonstrated features of VAHS. With hemodialysis and steroid treatment, he was successfully recovered

    Discrepant lesion size estimated on T1- and fat-suppressed T2-weighted MRI: diagnostic value for differentiation between inflammatory pseudotumor and carcinoma of the nasopharynx

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    PURPOSE:Nasopharyngeal inflammatory pseudotumor (NIPT) is hard to differentiate from infiltrating nasopharyngeal carcinoma (NPC) on conventional magnetic resonance imaging (MRI). The purpose of this study is to determine whether discrepant lesion sizes estimated on T1- and fat-suppressed T2-weighted images can help distinguish between NIPT and NPC.METHODS:We retrospectively reviewed MRI data of histologically proven 14 NIPTs and 18 infiltrating NPCs. We measured the area of the lesion on contrast-enhanced T1-weighted, unenhanced T1-weighted, and fat-suppressed T2-weighted images by placing the largest possible polygonal region-of-interest within the lesion at the same level. Using lesion size measured on contrast-enhanced T1-weighted image as the reference, we calculated and compared area ratio of T1 (ART1) and area ratio of T2 (ART2) between NIPTs and NPCs. For validation, we also undertook a double-blinded study by two reviewers and assessed the diagnostic performance and interobserver agreement.RESULTS:For NIPTs, ART2 (median, 0.48; range, 0.18–0.97) was statistically significantly less than ART1 (median, 1.01; range, 0.80–1.99), while these values were not significantly different for NPCs. The interobserver agreement in differentiating between NIPT and NPC was good, with a sensitivity of 93% and a specificity of 83%–94%.CONCLUSION:In contrast to NPCs, NIPTs appear smaller on fat-suppressed T2-weighted images than on T1-weighted images. This discrepancy in the lesion size estimated on T1-weighted and fat-suppressed T2-weighted images may provide a simple and consistent way to differentiate between NIPTs and NPCs on conventional MRI

    Mycoplasma pneumoniae infection in patients with Kawasaki disease

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    PurposeKawasaki disease (KD) is the main cause of acquired heart disease in children. In addition to cardiovascular involvement, many complications have been recognized in KD. However, respiratory complications have been rarely reported. We investigated the differences in clinical characteristics, laboratory findings, radiography findings, and echocardiography findings of Mycoplasma pneumoniae infection and other types of pneumonia in KD patients.MethodsAmong 358 patients with KD, 54 developed concurrent pneumonia. Among the 54 patients, 12 (22.2%) with high titers of anti-M. pneumoniae antibody (AMA) (>1:640) were grouped in the M. pneumoniae group and 42 were included in the control group. Serum AMA was measured in each patient. Clinical laboratory findings and total duration of fever were analyzed.ResultsThe duration of fever, serum hemoglobin, white blood cell count, platelet count, erythrocyte sedimentation rate, C-reactive protein level, albumin level, and the incidence of coronary arterial lesions showed no statistical difference in the 2 groups. Neutrophil count was significantly higher in the M. pneumoniae group than in the control group. Among various radiography findings observed in pneumonia, consolidation and pleural effusion were more frequent in the M. pneumoniae group than in the control group. On the other hand, parahilar peribronchial opacification, diffuse interstitial lesion, and normal findings prevailed in the control group.ConclusionKD patients can have concurrent infections, especially pulmonary symptoms. The cause of KD is likely to be associated with M. pneumoniae infection. Thus, immediate treatment of M. pneumoniae infection in KD patients is very important

    Effects of candesartan and propranolol combination therapy versus propranolol monotherapy in reducing portal hypertension

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    Background/AimsAngiotensin receptor blockers (ARBs) inhibit activated hepatic stellate cell contraction and are thought to reduce the dynamic portion of intrahepatic resistance. This study compared the effects of combined treatment using the ARB candesartan and propranolol versus propranolol monotherapy on portal pressure in patients with cirrhosis in a prospective, randomized controlled trial.MethodsBetween January 2008 and July 2009, 53 cirrhotic patients with clinically significant portal hypertension were randomized to receive either candesartan and propranolol combination therapy (26 patients) or propranolol monotherapy (27 patients). Before and 3 months after the administration of the planned medication, the hepatic venous pressure gradient (HVPG) was assessed in both groups. The dose of propranolol was subsequently increased from 20 mg bid until the target heart rate was reached, and the candesartan dose was fixed at 8 mg qd. The primary endpoint was the HVPG response rate; patients with an HVPG reduction of >20% of the baseline value or to <12 mmHg were defined as responders.ResultsThe mean portal pressure declined significantly in both groups, from 16 mmHg (range, 12-28 mmHg) to 13.5 mmHg (range, 6-20 mmHg) in the combination group (P<0.05), and from 17 mmHg (range, 12-27 mmHg) to 14 mmHg (range, 7-25 mmHg) in the propranolol monotherapy group (P<0.05). However, the medication-induced pressure reduction did not differ significantly between the two groups [3.5 mmHg (range, -3-11 mmHg) vs. 3 mmHg (range, -8-10 mmHg), P=0.674]. The response rate (55.6% vs. 61.5%, P=0.435) and the reductions in mean blood pressure or heart rate also did not differ significantly between the combination and monotherapy groups.ConclusionsThe addition of candesartan (an ARB) to propranolol confers no benefit relative to classical propranolol monotherapy for the treatment of portal hypertension, and is thus not recommended

    Carriage of the V279F Null Allele within the Gene Encoding Lp-PLA2 Is Protective from Coronary Artery Disease in South Korean Males

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    The Asia-specific PLA2G7 994G-T transversion leads to V279F substitution within the lipoprotein-associated phospholipase-A2 (Lp-PLAβ‚‚) and to absence of enzyme activity in plasma. This variant offers a unique natural experiment to assess the role of Lp-PLAβ‚‚ in the pathogenesis of coronary artery disease (CAD) in humans. Given conflicting results from mostly small studies, a large two-stage case-control study was warranted.PLA2G7 V279F genotypes were initially compared in 2890 male cases diagnosed with CAD before age 60 with 3128 male controls without CAD at age 50 and above and subsequently in a second independent male dataset of 877 CAD cases and 1230 controls. In the first dataset, the prevalence of the 279F null allele was 11.5% in cases and 12.8% in controls. After adjustment for age, body mass index, diabetes, smoking, glucose and lipid levels, the OR (95% CI) for CAD for this allele was 0.80 (0.66-0.97, pβ€Š=β€Š0.02). The results were very similar in the second dataset, despite lower power, with an allele frequency of 11.2% in cases and 12.5% in controls, leading to a combined OR of 0.80 (0.69-0.92), pβ€Š=β€Š0.002. The magnitude and direction of this genetic effect were fully consistent with large epidemiological studies on plasma Lp-PLAβ‚‚ activity and CAD risk.Natural deficiency in Lp-PLAβ‚‚ activity due to carriage of PLA2G7 279F allele protects from CAD in Korean men. These results provide evidence for a causal relationship between Lp-PLAβ‚‚ and CAD, and support pharmacological inhibition of this enzyme as an innovative way to prevent CAD

    Carriage of the V279F Null Allele within the Gene Encoding Lp-PLA2 Is Protective from Coronary Artery Disease in South Korean Males

    Get PDF
    The Asia-specific PLA2G7 994G-T transversion leads to V279F substitution within the lipoprotein-associated phospholipase-A2 (Lp-PLAβ‚‚) and to absence of enzyme activity in plasma. This variant offers a unique natural experiment to assess the role of Lp-PLAβ‚‚ in the pathogenesis of coronary artery disease (CAD) in humans. Given conflicting results from mostly small studies, a large two-stage case-control study was warranted.PLA2G7 V279F genotypes were initially compared in 2890 male cases diagnosed with CAD before age 60 with 3128 male controls without CAD at age 50 and above and subsequently in a second independent male dataset of 877 CAD cases and 1230 controls. In the first dataset, the prevalence of the 279F null allele was 11.5% in cases and 12.8% in controls. After adjustment for age, body mass index, diabetes, smoking, glucose and lipid levels, the OR (95% CI) for CAD for this allele was 0.80 (0.66-0.97, pβ€Š=β€Š0.02). The results were very similar in the second dataset, despite lower power, with an allele frequency of 11.2% in cases and 12.5% in controls, leading to a combined OR of 0.80 (0.69-0.92), pβ€Š=β€Š0.002. The magnitude and direction of this genetic effect were fully consistent with large epidemiological studies on plasma Lp-PLAβ‚‚ activity and CAD risk.Natural deficiency in Lp-PLAβ‚‚ activity due to carriage of PLA2G7 279F allele protects from CAD in Korean men. These results provide evidence for a causal relationship between Lp-PLAβ‚‚ and CAD, and support pharmacological inhibition of this enzyme as an innovative way to prevent CAD

    Single nucleotide polymorphisms in bone turnover-related genes in Koreans: ethnic differences in linkage disequilibrium and haplotype

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    <p>Abstract</p> <p>Background</p> <p>Osteoporosis is defined as the loss of bone mineral density that leads to bone fragility with aging. Population-based case-control studies have identified polymorphisms in many candidate genes that have been associated with bone mass maintenance or osteoporotic fracture. To investigate single nucleotide polymorphisms (SNPs) that are associated with osteoporosis, we examined the genetic variation among Koreans by analyzing 81 genes according to their function in bone formation and resorption during bone remodeling.</p> <p>Methods</p> <p>We resequenced all the exons, splice junctions and promoter regions of candidate osteoporosis genes using 24 unrelated Korean individuals. Using the common SNPs from our study and the HapMap database, a statistical analysis of deviation in heterozygosity depicted.</p> <p>Results</p> <p>We identified 942 variants, including 888 SNPs, 43 insertion/deletion polymorphisms, and 11 microsatellite markers. Of the SNPs, 557 (63%) had been previously identified and 331 (37%) were newly discovered in the Korean population. When compared SNPs in the Korean population with those in HapMap database, 1% (or less) of SNPs in the Japanese and Chinese subpopulations and 20% of those in Caucasian and African subpopulations were significantly differentiated from the Hardy-Weinberg expectations. In addition, an analysis of the genetic diversity showed that there were no significant differences among Korean, Han Chinese and Japanese populations, but African and Caucasian populations were significantly differentiated in selected genes. Nevertheless, in the detailed analysis of genetic properties, the LD and Haplotype block patterns among the five sub-populations were substantially different from one another.</p> <p>Conclusion</p> <p>Through the resequencing of 81 osteoporosis candidate genes, 118 unknown SNPs with a minor allele frequency (MAF) > 0.05 were discovered in the Korean population. In addition, using the common SNPs between our study and HapMap, an analysis of genetic diversity and deviation in heterozygosity was performed and the polymorphisms of the above genes among the five populations were substantially differentiated from one another. Further studies of osteoporosis could utilize the polymorphisms identified in our data since they may have important implications for the selection of highly informative SNPs for future association studies.</p
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