795 research outputs found

    Anti-Apoptotic Effects of SERPIN B3 and B4 via STAT6 Activation in Macrophages after Infection with Toxoplasma gondii

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    Toxoplasma gondii penetrates all kinds of nucleated eukaryotic cells but modulates host cells differently for its intracellular survival. In a previous study, we found out that serine protease inhibitors B3 and B4 (SERPIN B3/B4 because of their very high homology) were significantly induced in THP-1-derived macrophages infected with T. gondii through activation of STAT6. In this study, to evaluate the effects of the induced SERPIN B3/B4 on the apoptosis of T. gondii-infected THP-1 cells, we designed and tested various small interfering (si-) RNAs of SERPIN B3 or B4 in staurosporine-induced apoptosis of THP-1 cells. Anti-apoptotic characteristics of THP-1 cells after infection with T. gondii disappeared when SERPIN B3/B4 were knock-downed with gene specific si-RNAs transfected into THP-1 cells as detected by the cleaved caspase 3, poly-ADP ribose polymerase and DNA fragmentation. This anti-apoptotic effect was confirmed in SERPIN B3/B4 overexpressed HeLa cells. We also investigated whether inhibition of STAT6 affects the function of SERPIN B3/B4, and vice versa. Inhibition of SERPIN B3/B4 did not influence STAT6 expression but SERPIN B3/B4 expression was inhibited by STAT6 si-RNA transfection, which confirmed that SERPIN B3/B4 was induced under the control of STAT6 activation. These results suggest that T. gondii induces SERPIN B3/B4 expression via STAT6 activation to inhibit the apoptosis of infected THP-1 cells for longer survival of the intracellular parasites themselves

    An autoregulatory loop controlling orphan nuclear receptor DAX-1 gene expression by orphan nuclear receptor ERRγ

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    The estrogen receptor-related receptor gamma (ERRγ/ERR3/NR3B3) is a member of the nuclear receptor superfamily that activates transcription in the absence of ligand. However, the detailed mechanism of gene regulation by ERRγ is not fully understood. In this study we have found that the orphan nuclear receptor ERRγ activates the DAX-1 promoter, which, in turn, represses transactivation by ERRγ. Serial deletions of mouse DAX-1 (mDAX-1) gene promoter have revealed that the region responding to ERRγ is located between −129 and −121 bp and −334 and −326 bp. Gel shift assays and chromatin immunoprecipitation (ChIP) assays demonstrated that ERRγ binds directly to the mDAX-1 promoter. Site-directed mutagenesis results demonstrated that ERRE1 (−129 to −121 bp) is more important than ERRE2 (−334 to −326 bp) which is not conserved in the human DAX-1 promoter. In addition, adenovirus-mediated overexpression of ERRγ induced DAX-1 gene expression in MCF-7 breast cancer cells that co-expressed ERRγ and DAX-1. Moreover, yeast two-hybrid and glutathione S-transferase (GST)-pull down assays demonstrated that DAX-1 physically interacted with ERRγ and inhibited ERRγ transactivation, and that this interaction was dependent on the AF-2 domain of ERRγ. In addition, in vitro competition assays showed that DAX-1 inhibited PGC-1α mediated ERRγ transactivation, via competition between these two factors for the AF-2 binding domain. We thus propose a novel autoregulatory loop that controls DAX-1 gene expression by ERRγ

    Cell type–dependent variation in paracrine potency determines therapeutic efficacy against neonatal hyperoxic lung injury

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    AbstractBackground aimsThe aim of this study was to determine the optimal cell type for transplantation to protect against neonatal hyperoxic lung injury. To this end, the in vitro and in vivo therapeutic efficacies and paracrine potencies of human umbilical cord blood–derived mesenchymal stromal cells (HUMs), human adipose tissue–derived mesenchymal stromal cells (HAMs) and human umbilical cord blood mononuclear cells (HMNs) were compared.MethodsHyperoxic injury was induced in vitro in A549 cells by challenge with H2O2. Alternatively, hyperoxic injury was induced in newborn Sprague-Dawley rats in vivo by exposure to hyperoxia (90% oxygen) for 14 days. HUMs, HAMs or HMNs (5 × 105 cells) were given intratracheally at postnatal day 5.ResultsHyperoxia-induced increases in in vitro cell death and in vivo impaired alveolarization were significantly attenuated in both the HUM and HAM groups but not in the HMN group. Hyperoxia impaired angiogenesis, increased the cell death and pulmonary macrophages and elevated inflammatory cytokine levels. These effects were significantly decreased in the HUM group but not in the HAM or HMN groups. The levels of human vascular endothelial growth factor and hepatocyte growth factor produced by donor cells were highest in HUM group, followed by HAM group and then HMN group.ConclusionsHUMs exhibited the best therapeutic efficacy and paracrine potency than HAMs or HMNs in protecting against neonatal hyperoxic lung injury. These cell type-dependent variations in therapeutic efficacy might be associated or mediated with the paracrine potency of the transplanted donor cells

    Idiopathic severe hypermagnesemia in an extremely low birth weight infant on the first day of life

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    A preterm female infant born at 27 weeks of gestation with a birth weight of 990 g developed acute hypotonia, apnea, hypotension and bradycardia mimicking septic shock syndrome at 14h after birth. Laboratory tests indicated a severe hypermagnesemia of 45 mg/dL. The renal function, complete blood count and maternal blood concentrations of magnesium were normal, and the blood cultures were negative. The patient recovered with treatment including exchange transfusion. However, the etiology of the severe hypermagnesemia remains unknown

    Necrotizing Sialometaplasia Accompanied by Adenoid Cystic Carcinoma on the Soft Palate

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    Necrotizing Sialometaplasia (NS) is a benign, self-limiting inflammatory disease of the mucus-secreting glands, and this illness mainly involves the minor salivary glands. The significance of NS resides in its clinical and histopathological resemblance to malignancy. We present here a case of necrotizing sialometaplasia on the soft palate, and this was accompanied by adenoid cystic carcinoma. We report here on this case to draw attention to the difficulty for deciding the extent of resecting a malignancy, and especially when the malignancy is simultaneously accompanied by necrotizing sialometaplasia

    Red Ginseng Extract Attenuates Kainate-Induced Excitotoxicity by Antioxidative Effects

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    This study investigated the neuroprotective activity of red ginseng extract (RGE, Panax ginseng, C. A. Meyer) against kainic acid- (KA-) induced excitotoxicity in vitro and in vivo. In hippocampal cells, RGE inhibited KA-induced excitotoxicity in a dose-dependent manner as measured by the MTT assay. To study the possible mechanisms of the RGE-mediated neuroprotective effect against KA-induced cytotoxicity, we examined the levels of intracellular reactive oxygen species (ROS) and [Ca2+]i in cultured hippocampal neurons and found that RGE treatment dose-dependently inhibited intracellular ROS and [Ca2+]i elevation. Oral administration of RGE (30 and 200 mg/kg) in mice decreased the malondialdehyde (MDA) level induced by KA injection (30 mg/kg, i.p.). In addition, similar results were obtained after pretreatment with the radical scavengers Trolox and N, N′-dimethylthiourea (DMTU). Finally, after confirming the protective effect of RGE on hippocampal brain-derived neurotropic factor (BDNF) protein levels, we found that RGE is active compounds mixture in KA-induced hippocampal mossy-fiber function improvement. Furthermore, RGE eliminated 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, and the IC50 was approximately 10 mg/ml. The reductive activity of RGE, as measured by reaction with hydroxyl radical (•OH), was similar to trolox. The second-order rate constant of RGE for •OH was 3.5–4.5×109 M−1·S−1. Therefore, these results indicate that RGE possesses radical reduction activity and alleviates KA-induced excitotoxicity by quenching ROS in hippocampal neurons

    Effect of intracoronary adenosine on ergonovine-induced vasoconstricted coronary arteries

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    Background: This study aimed to evaluate the effect of adenosine on epicardial coronary artery diameterduring ergonovine provocation testing.Methods: A total of 158 patients who underwent an ergonovine provocation test with intracoronaryadenosine injection between 2011 and 2014 were selected. Patients were divided into four groups basedon the severity of percent diameter stenosis following intracoronary ergonovine administration: Group 1,induced spasm < 50%; Group 2, 50–89%; Group 3, 90–99%; and Group 4, total occlusion.Results: Spasm positivity was observed in 44 (27.8%) cases in the study population (mean age, 57.4 ±± 10.7 years). Intracoronary adenosine increased the diameter of the ergonovine-induced epicardialartery by 0.51 ± 0.31 mm, 0.73 ± 0.39 mm, 0.44 ± 0.59 mm, and 0.01 ± 0.04 mm in Groups 1, 2, 3,and 4, respectively. Subsequent administration of nitroglycerin further increased vessel diameter by0.49 ± 0.28 mm, 0.93 ± 0.68 mm, 2.11 ± 1.25 mm, and 2.23 ± 0.69 mm in Groups 1, 2, 3, and 4,respectively. The ratios of adenosine-induced diameter to reference diameter were significantly lowerin patients with spasm positive results (0.68 [0.59–0.76] vs. 0.18 [0.00–0.41], p < 0.001 in the studypopulation; 0.60 [0.54–0.67] vs. 0.40 [0.27–0.44], p < 0.001 in Group 2) with the best cut-off value of0.505 (sensitivity 0.955, specificity 0.921).Conclusions: Intracoronary administration of adenosine dilated the ergonovine-induced vasoconstrictedepicardial coronary artery. The ratio of adenosine-induced diameter to reference diameter wassignificantly lower in patients with spasm positive results
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