39 research outputs found
A Case of Non-Functioning Huge Adrenocortical Carcinoma Extending Into Inferior Vena Cava and Right Atrium
Primary adrenocortical carcinoma (ACC) is a rare tumor and its usual sites of metastasis are the lung (71%), lymph node (68%), liver (42%), and bone (26%). However, intracaval invasion extending into the right atrium is very rare and spontaneous regression of tumor burden in adrenal carcinoma is also rare. We report a case of ACC with direct invasion of the inferior vena cava and right atrium. A 34-yr-old male patient presented with progressive dyspnea, weight loss, and poor oral intake over 3 months. Non-functioning ACC with direct invasion of the inferior vena cava and right atrium was confirmed by imaging, pathologic, and hormonal study. Chemo-radio-therapy was attempted. However, tumor burden was not changed, but rather toxic hepatitis and thrombocytopenia were developed. His subjective symptoms and general conditions were improved after 1 month of conservative management and the patient was discharged. During clinical follow-up, this tumor showed spontaneous regression
CpG methylation at GATA elements in the regulatory region of CCR3 positively correlates with CCR3 transcription
DNA methylation may regulate gene expression by restricting the access of transcription factors. We have previously demonstrated that GATA-1 regulates the transcription of the CCR3 gene by dynamically interacting with both positively and negatively acting GATA elements of high affinity binding in the proximal promoter region including exon 1. Exon 1 has three CpG sites, two of which are positioned at the negatively acting GATA elements. We hypothesized that the methylation of these two CpGs sites might preclude GATA-1 binding to the negatively acting GATA elements and, as a result, increase the availability of GATA-1 to the positively acting GATA element, thereby contributing to an increase in GATA-1-mediated transcription of the gene. To this end, we determined the methylation of the three CpG sites by bisulfate pyrosequencing in peripheral blood eosinophils, cord blood (CB)-derived eosinophils, PBMCs, and cell lines that vary in CCR3 mRNA expression. Our results demonstrated that methylation of CpG sites at the negatively acting GATA elements severely reduced GATA-1 binding and augmented transcription activity in vitro. In agreement, methylation of these CpG sites positively correlated with CCR3 mRNA expression in the primary cells and cell lines examined. Interestingly, methylation patterns of these three CpG sites in CB-derived eosinophils mostly resembled those in peripheral blood eosinophils. These results suggest that methylation of CpG sites at the GATA elements in the regulatory regions fine-tunes CCR3 transcription
Eosinophil Development, Regulation of Eosinophil-Specific Genes, and Role of Eosinophils in the Pathogenesis of Asthma
Eosinophils arise from hematopoietic CD34+ stem cells in the bone marrow. They acquire IL-5Rα on their surface at a very early stage during eosinophilopoiesis, and differentiate under the strong influence of interleukin (IL)-5. They then exit to the bloodstream, and enter the lung upon exposure to airway inflammatory signals, including eotaxins. In inflamed tissues, eosinophils act as key mediators of terminal effector functions and innate immunity and in linking to adaptive immune responses. Transcription factors GATA-1, CCAAT/enhancer-binding protein, and PU.1 play instructive roles in eosinophil specification from multipotent stem cells through a network of cooperative and antagonistic interactions. Not surprisingly, the interplay of these transcription factors is instrumental in forming the regulatory circuit of expression of eosinophil-specific genes, encoding eosinophil major basic protein and neurotoxin, CC chemokine receptor 3 eotaxin receptor, and IL-5 receptor alpha. Interestingly, a common feature is that the critical cis-acting elements for these transcription factors are clustered in exon 1 and intron 1 of these genes rather than their promoters. Elucidation of the mechanism of eosinophil development and activation may lead to selective elimination of eosinophils in animals and human subjects. Furthermore, availability of a range of genetically modified mice lacking or overproducing eosinophil-specific genes will facilitate evaluation of the roles of eosinophils in the pathogenesis of asthma. This review summarizes eosinophil biology, focusing on development and regulation of eosinophil-specific genes, with a heavy emphasis on the causative link between eosinophils and pathological development of asthma using genetically modified mice as models of asthma
Fatty Acid Binding Protein 1 Is Related with Development of Aspirin-Exacerbated Respiratory Disease
BACKGROUND: Aspirin-exacerbated respiratory disease (AERD) refers to the development of bronchoconstriction in asthmatics following the ingestion of aspirin. Although alterations in eicosanoid metabolites play a role in AERD, other immune or inflammatory mechanisms may be involved. We aimed to identify proteins that were differentially expressed in nasal polyps between patients with AERD and aspirin-tolerant asthma (ATA). METHODOLOGY/PRINCIPAL FINDINGS: Two-dimensional electrophoresis was adopted for differential display proteomics. Proteins were identified by liquid chromatography-tandem mass spectrometry (LC-MS). Western blotting and immunohistochemical staining were performed to compare the amount of fatty acid-binding protein 1 (FABP1) in the nasal polyps of patients with AERD and ATA. Fifteen proteins were significantly up- (seven spots) or down-regulated in the nasal polyps of patients with AERD (n = 5) compared to those with ATA (n = 8). LC-MS revealed an increase in seven proteins expression and a decrease in eight proteins expression in patients with AERD compared to those with ATA (P = 0.003-0.045). FABP1-expression based on immunoblotting and immunohistochemical analysis was significantly higher in the nasal polyps of patients with AERD compared to that in patients with ATA. FABP1 was observed in epithelial, eosinophils, macrophages, and the smooth-muscle cells of blood vessels in the polyps. CONCLUSIONS/SIGNIFICANCE: Our results indicate that alterations in 15 proteins, including FABP1, may be related to the development of AERD
Lysophosphatidylserine Induces MUC5AC Production via the Feedforward Regulation of the TACE-EGFR-ERK Pathway in Airway Epithelial Cells in a Receptor-Independent Manner
Lysophosphatidylserine (LysoPS) is an amphipathic lysophospholipid that mediates a broad spectrum of inflammatory responses through a poorly characterized mechanism. Because LysoPS levels can rise in a variety of pathological conditions, we sought to investigate LysoPSâs potential role in airway epithelial cells that actively participate in lung homeostasis. Here, we report a previously unappreciated function of LysoPS in production of a mucin component, MUC5AC, in the airway epithelial cells. LysoPS stimulated lung epithelial cells to produce MUC5AC via signaling pathways involving TACE, EGFR, and ERK. Specifically, LysoPS- dependent biphasic activation of ERK resulted in TGF-α secretion and strong EGFR phosphorylation leading to MUC5AC production. Collectively, LysoPS induces the expression of MUC5AC via a feedback loop composed of proligand synthesis and its proteolysis by TACE and following autocrine EGFR activation. To our surprise, we were not able to find a role of GPCRs and TLR2, known LyoPS receptors in LysoPS-induced MUC5AC production in airway epithelial cells, suggesting a potential receptor-independent action of LysoPS during inflammation. This study provides new insight into the potential function and mechanism of LysoPS as an emerging lipid mediator in airway inflammation
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Interleukin-1ÎČ induction of tumor necrosis factor-alpha gene expression in human astroglioma cells
Cells that produce tumor necrosis factor-α (TNF-α) require the presence of signaling molecules since this cytokine is not normally expressed in a constitutive manner. It has been demonstrated that glial cells can produce TNF-α; however, the specific inducing molecules and their mechanism(s) of action have not been clearly defined. In this study, we examined the effect of human recombinant interleukin-1ÎČ (IL-1ÎČ) on the expression of TNF-α by CH235-MG human malignant glioma cells. CH235-MG cells do not constitutively express TNF-α mRNA or protein; however, upon stimulation with IL-1ÎČ, these cells synthesize and secrete biologically active TNF-α. IL-1ÎČ induces the expression of a 1.9 kb TNF-α mRNA species. Kinetic analysis demonstrated optimum TNF-α mRNA expression after a 4 h exposure to IL-1ÎČ, and peak TNF-α protein production at 18 h. Cycloheximide (CHX), an inhibitor of protein synthesis, markedly increases expression of TNF-α mRNA in IL-1ÎČ stimulated CH235-MG cells, indicating that de novo protein synthesis is not required for astroglioma TNF-α gene expression. Nuclear run-off analysis demonstrates that IL-1ÎČ causes transcriptional activation of the TNF-α gene, and CHX enhances, IL-1ÎČ-induced TNF-α transcription. Studies of TNF-α mRNA stability using actinomycin D show that IL-1ÎČ-induced TNF-α mRNA has a half-life of approximately 30 min, and CHX increases the half-life of IL-1ÎČ-induced TNF-α mRNA to approximately 210 min. These results indicate that IL-1ÎČ, a cytokine present in the central nervous system during some pathological disease states, is a potent inducer of TNF-α in human malignant glioma cells