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1.
Blood Adv ; 7(16): 4599-4607, 2023 08 22.
Article in English | MEDLINE | ID: mdl-37236162

ABSTRACT

While molecular testing of hematologic malignancies is now standard of care, there is variability in practice and testing capabilities between different academic laboratories, with common questions arising on how to best meet clinical expectations. A survey was sent to hematopathology subgroup members of the Genomics Organization for Academic Laboratories consortium to assess current and future practice and potentially establish a reference for peer institutions. Responses were received from 18 academic tertiary-care laboratories regarding next-generation sequencing (NGS) panel design, sequencing protocols and metrics, assay characteristics, laboratory operations, case reimbursement, and development plans. Differences in NGS panel size, use, and gene content were reported. Gene content for myeloid processes was reported to be generally excellent, while genes for lymphoid processes were less well covered. The turnaround time (TAT) for acute cases, including acute myeloid leukemia, was reported to range from 2 to 7 calendar days to 15 to 21 calendar days, with different approaches to achieving rapid TAT described. To help guide NGS panel design and standardize gene content, consensus gene lists based on current and future NGS panels in development were generated. Most survey respondents expected molecular testing at academic laboratories to continue to be viable in the future, with rapid TAT for acute cases likely to remain an important factor. Molecular testing reimbursement was reported to be a major concern. The results of this survey and subsequent discussions improve the shared understanding of differences in testing practices for hematologic malignancies between institutions and will help provide a more consistent level of patient care.


Subject(s)
Goals , Hematologic Neoplasms , Humans , Hematologic Neoplasms/diagnosis , Hematologic Neoplasms/genetics , Genomics/methods , High-Throughput Nucleotide Sequencing/methods
2.
Int J Clin Exp Pathol ; 15(1): 38-45, 2022.
Article in English | MEDLINE | ID: mdl-35145582

ABSTRACT

Esophageal carcinoma cuniculatum (ECC) is a rare form of extremely well-differentiated squamous cell carcinoma of esophagus that is often misdiagnosed preoperatively. The molecular changes underlying ECC remain unknown. This study aimed to explore the molecular signature of ECC using next-generation sequencing (NGS). Five cases of ECC were collected from our pathology database from 2014 to 2019. One patient received chemoradiation and the remaining four patients were treatment-naïve. Areas of normal squamous mucosa, non-invasive component, and invasive component of ECC were circled and macrodissected. Genomic DNA extracted from the macrodissected tissue was sequenced using GatorSeq NGS Panel. Deleterious mutations, predicted by Sorting Intolerant from Tolerant (SIFT), were identified using tumor/normal pairs and annotated by amino acid change. The normal-appearing squamous mucosa in the ECC harbored recurrent deleterious somatic mutations in ROS1 and POLE genes. ECC tumor-specific deleterious mutations were identified on TP53, NOTCH1, and PIK3CA genes. Our results support a mutually exclusive pattern in NOTCH1 and PIK3CA mutation. Non-invasive and invasive components in ECC had identical mutation profiles. Chemoradiation therapy led to disappearance of NOTCH1 mutation in one ECC case. Our results suggest molecular testing may help pre-operative diagnosis, and provide therapeutic targets in patients with advanced or unresectable ECC.

3.
Mol Cancer Res ; 20(2): 293-304, 2022 02.
Article in English | MEDLINE | ID: mdl-34635505

ABSTRACT

FMS-like tyrosine kinase 3 (FLT3) is one of the most frequently mutated genes in acute myeloid leukemia (AML), with the most common mutation being internal tandem duplications (ITD). The presence of FLT3-ITD in AML carries a particularly poor prognosis and renders therapeutic resistance. New druggable targets are thus needed in this disease. In this study, we demonstrate the effects of de novo creatine biosynthesis upregulation by FLT3-ITD on AML sustainability. Our data show that FLT3-ITD constitutively activates the STAT5 signaling pathway, which upregulates the expression of glycine amidinotransferase (GATM), the first rate-limiting enzyme of de novo creatine biosynthesis. Pharmacologic FLT3-ITD inhibition reduces intracellular creatinine levels through transcriptional downregulation of genes in the de novo creatine biosynthesis pathway. The same reduction can be achieved by cyclocreatine or genetic GATM knockdown with shRNA and is reflected in significant decrease of cell proliferation and moderate increase of cell apoptosis in FLT3-ITD-mutant cell lines. Those effects are at least partially mediated through the AMPK/mTOR signaling pathway. This study uncovers a previously uncharacterized role of creatine metabolic pathway in the maintenance of FLT3-ITD-mutant AML and suggests that targeting this pathway may serve as a promising therapeutic strategy for FLT3-ITD-positive AML. IMPLICATIONS: FLT3-ITD mutation in AML upregulates de novo creatine biosynthesis that we show can be suppressed to diminish the proliferation and survival of blast cells.


Subject(s)
Amidinotransferases/metabolism , Creatine/metabolism , Leukemia, Myeloid, Acute/genetics , fms-Like Tyrosine Kinase 3/metabolism , Cell Line, Tumor , Cell Proliferation , Humans , Leukemia, Myeloid, Acute/pathology , Mutation , Signal Transduction , Transfection
4.
Acad Pathol ; 8: 23742895211020485, 2021.
Article in English | MEDLINE | ID: mdl-34189259

ABSTRACT

The global rise of the coronavirus disease 2019 pandemic resulted in an exponentially increasing demand for severe acute respiratory syndrome coronavirus 2 testing, which resulted in shortage of reagents worldwide. This shortage has been further worsened by screening of asymptomatic populations such as returning employees, students, and so on, as part of plans to reopen the economy. To optimize the utilization of testing reagents and human resources, pool testing of populations with low prevalence has emerged as a promising strategy. Although pooling is an effective solution to reduce the number of reagents used for testing, the process of pooling samples together and tracking them throughout the entire workflow is challenging. To be effective, samples must be tracked into each pool, pool-tested and reported individually. In this article, we address these challenges using robotics and informatics.

6.
Clin Pharmacol Ther ; 108(3): 557-565, 2020 09.
Article in English | MEDLINE | ID: mdl-32460360

ABSTRACT

There have been significant advancements in precision medicine and approaches to medication selection based on pharmacogenetic results. With the availability of direct-to-consumer genetic testing and growing awareness of genetic interindividual variability, patient demand for more precise, individually tailored drug regimens is increasing. The University of Florida (UF) Health Precision Medicine Program (PMP) was established in 2011 to improve integration of genomic data into clinical practice. In the ensuing years, the UF Health PMP has successfully implemented several single-gene tests to optimize the precision of medication prescribing across a variety of clinical settings. Most recently, the UF Health PMP launched a custom-designed pharmacogenetic panel, including pharmacogenes relevant to supportive care medications commonly prescribed to patients undergoing chemotherapy treatment, referred to as "GatorPGx." This tutorial provides guidance and information to institutions on how to transition from the implementation of single-gene pharmacogenetic testing to a preemptive panel-based testing approach. Here, we demonstrate application of the preemptive panel in the setting of an adult solid tumor oncology clinic. Importantly, the information included herein can be applied to other clinical practice settings.


Subject(s)
Antineoplastic Agents/therapeutic use , Gene Expression Profiling , Pharmacogenomic Testing , Pharmacogenomic Variants , Precision Medicine , Antineoplastic Agents/adverse effects , Antineoplastic Agents/pharmacokinetics , Clinical Decision-Making , Decision Support Systems, Clinical , Decision Support Techniques , Drug Interactions , Genetic Counseling , Humans , Pharmacogenetics , Polypharmacy , Predictive Value of Tests , Program Development , Program Evaluation
7.
JAMIA Open ; 3(4): 523-529, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33754137

ABSTRACT

Coronavirus disease 2019, first reported in China in late 2019, has quickly spread across the world. The outbreak was declared a pandemic by the World Health Organization on March 11, 2020. Here, we describe our initial efforts at the University of Florida Health for processing of large numbers of tests, streamlining data collection, and reporting data for optimizing testing capabilities and superior clinical management. Specifically, we discuss clinical and pathology informatics workflows and informatics instruments which we designed to meet the unique challenges of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing. We hope these results benefit institutions preparing to implement SARS-CoV-2 testing.

8.
Int J Surg Pathol ; 28(1): 102-108, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31382829

ABSTRACT

SMARCA4-deficient thoracic sarcoma (SMARCA4-DTS) is a recently described entity with a poor prognosis that is defined by certain genetic alterations in the BAF chromatin remodeling complex, specifically SMARCA4 and SMARCA2. We present a case of a SMARCA4-DTS in a 59 year-old male with a heavy smoking history who was found to have an unexpected right upper lobe lung mass on routine chest radiograph after a visit to his primary care physician. This led to a biopsy with a diagnosis of poorly differentiated carcinoma at an outside institution. The patient was subsequently seen at our facility for surgical intervention. The right upper lobectomy contained a 7.2-cm poorly differentiated malignancy with slightly discohesive cells arranged in sheets and nests, abundant geographic necrosis, and with many areas showing rhabdoid morphology. The tumor was focally reactive for CK7, AE1/3, Cam5.2, and SALL4 and showed scattered reactivity for CD34 and SOX2. There was complete loss of reactivity for both SMARCA4 and SMARCA2. The histology and immunophenotype were all consistent with the diagnosis of a SMARCA4-DTS. Next-generation sequencing showed a frameshift mutation in the SMARCA4 gene and no abnormality with the SMARCA2 gene. Interestingly, this tumor was confined to the pulmonary parenchyma with no invasion of the visceral pleura nor the mediastinum and with no clinically apparent metastases at the time of presentation. This case is presented to add to the cohort of cases described to date and to discuss the immunohistochemical and molecular findings with regard to SMARCA2.


Subject(s)
Biomarkers, Tumor/deficiency , DNA Helicases/deficiency , Lung Neoplasms/diagnosis , Nuclear Proteins/deficiency , Sarcoma/diagnosis , Transcription Factors/deficiency , Humans , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Middle Aged , Sarcoma/metabolism , Sarcoma/pathology
11.
Biochim Biophys Acta ; 1839(11): 1205-16, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24953189

ABSTRACT

Manganese superoxide dismutase (MnSOD), a critical anti-oxidant enzyme, detoxifies the mitochondrial-derived reactive oxygen species, superoxide, elicited through normal respiration or the inflammatory response. Proinflammatory stimuli induce MnSOD gene expression through a eutherian-conserved, intronic enhancer element. We identified two prototypic enhancer binding proteins, TEAD1 and p65, that when co-expressed induce MnSOD expression comparable to pro-inflammatory stimuli. TEAD1 causes the nuclear sequestration of p65 leading to a novel TEAD1/p65 complex that associates with the intronic enhancer and is necessary for cytokine induction of MnSOD. Unlike typical NF-κB-responsive genes, the induction of MnSOD does not involve p50. Beyond MnSOD, the TEAD1/p65 complex regulates a subset of genes controlling the innate immune response that were previously viewed as solely NF-κB-dependent. We also identified an enhancer-derived RNA (eRNA) that is induced by either proinflammatory stimuli or the TEAD1/p65 complex, potentially linking the intronic enhancer to intra- and interchromosomal gene regulation through the inducible eRNA.


Subject(s)
DNA-Binding Proteins/physiology , Enhancer Elements, Genetic/genetics , Gene Expression Regulation , Immunity, Innate/genetics , Nuclear Proteins/physiology , RNA/genetics , Superoxide Dismutase/genetics , Transcription Factor RelA/physiology , Transcription Factors/physiology , Animals , Base Sequence , Cells, Cultured , DNA-Binding Proteins/metabolism , Humans , Introns , Molecular Sequence Data , Nuclear Proteins/metabolism , Protein Binding , RNA/metabolism , Rats , TEA Domain Transcription Factors , Transcription Factor RelA/metabolism , Transcription Factors/metabolism
12.
PLoS One ; 9(3): e92698, 2014.
Article in English | MEDLINE | ID: mdl-24667434

ABSTRACT

The role of systemic autoimmunity in human traumatic brain injury (TBI) and other forms of brain injuries is recognized but not well understood. In this study, a systematic investigation was performed to identify serum autoantibody responses to brain-specific proteins after TBI in humans. TBI autoantibodies showed predominant immunoreactivity against a cluster of bands from 38-50 kDa on human brain immunoblots, which were identified as GFAP and GFAP breakdown products. GFAP autoantibody levels increased by 7 days after injury, and were of the IgG subtype predominantly. Results from in vitro tests and rat TBI experiments also indicated that calpain was responsible for removing the amino and carboxyl termini of GFAP to yield a 38 kDa fragment. Additionally, TBI autoantibody staining co-localized with GFAP in injured rat brain and in primary rat astrocytes. These results suggest that GFAP breakdown products persist within degenerating astrocytes in the brain. Anti-GFAP autoantibody also can enter living astroglia cells in culture and its presence appears to compromise glial cell health. TBI patients showed an average 3.77 fold increase in anti-GFAP autoantibody levels from early (0-1 days) to late (7-10 days) times post injury. Changes in autoantibody levels were negatively correlated with outcome as measured by GOS-E score at 6 months, suggesting that TBI patients with greater anti-GFAP immune-responses had worse outcomes. Due to the long lasting nature of IgG, a test to detect anti-GFAP autoantibodies is likely to prolong the temporal window for assessment of brain damage in human patients.


Subject(s)
Autoantibodies , Brain Injuries/blood , Brain Injuries/immunology , Glial Fibrillary Acidic Protein/immunology , Immunoglobulin G , Adult , Animals , Astrocytes/immunology , Astrocytes/metabolism , Astrocytes/pathology , Autoantibodies/blood , Autoantibodies/immunology , Brain Injuries/pathology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Male , Rats , Rats, Sprague-Dawley , Time Factors
13.
Fertil Steril ; 101(5): 1450-7, 2014 May.
Article in English | MEDLINE | ID: mdl-24559722

ABSTRACT

OBJECTIVE: To demonstrate that a small molecule can induce the transcription factor Foxo3 in the ovary and lead to inhibition of follicle activation. DESIGN: Cell culture, organ culture, and animal studies. SETTING: University-based laboratory. ANIMAL(S): 23 female C57BL/6 mice. INTERVENTION(S): Human ovary cells and mouse ovaries in culture treated with 2-deoxyglucose (2-DG) to mimic glucose deprivation, and mice intraperitoneally injected with 100 mg/kg, 300 mg/kg, or 600 mg/kg 2-DG daily for 2 weeks. MAIN OUTCOME MEASURE(S): In cell and organ culture, Foxo3 expression analyzed by quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR); in treated animals, expression of genes regulated by nutrient deprivation (Foxo3, ATF4, GRP78, CHOP, ASNS, c-Myc) measured in brain, kidney, and ovary by qRT-PCR; and ovarian follicles histologically classified and counted. RESULT(S): Foxo3 expression is induced by 2-DG at both the mRNA and protein level in human ovarian cell culture, possibly through ATF4-dependent gene regulation. Foxo3 expression is also induced by 2-DG in ovarian organ culture. Treatment of mice with 100 mg/kg 2-DG resulted in a 2.6 fold induction of Foxo3 in the ovary and a 58% decrease in type 3a primary follicles. CONCLUSION(S): Expression of Foxo3 is induced by nutrient deprivation in cell culture, organ culture, and in vivo. In mice, 2-DG treatment results in an inhibition of primordial follicle activation. These data indicate that Foxo3 induction by 2-DG may be useful for fertility preservation.


Subject(s)
Ovarian Follicle/cytology , Ovarian Follicle/metabolism , Animals , Cell Line, Transformed , Cell Line, Tumor , Cells, Cultured , Deoxyglucose/pharmacology , Endoplasmic Reticulum Chaperone BiP , Female , Forkhead Box Protein O3 , Forkhead Transcription Factors/biosynthesis , Forkhead Transcription Factors/genetics , Gene Expression Regulation/physiology , Humans , Mice , Mice, Inbred C57BL , Organ Culture Techniques , Ovarian Follicle/drug effects
14.
J Lipid Res ; 54(7): 1915-26, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23549331

ABSTRACT

Specific control of group IVA cytosolic phospholipase A2 (cPLA2α or PLA2G4A) expression modulates arachidonic acid production, thus tightly regulating the downstream effects of pro- and anti-inflammatory eicosanoids. The significance of this pathway in human disease is apparent in a range of pathologies from inflammation to tumorigenesis. While much of the regulation of cPLA2α has focused on posttranslational phosphorylation of the protein, studies on transcriptional regulation of this gene have focused only on proximal promoter regions. We have identified a DNase I hypersensitive site encompassing a 5' distal enhancer element containing a highly conserved consensus AP-1 site involved in transcriptional activation of cPLA2α by interleukin (IL)-1ß. Chromatin immunoprecipitation (ChIP), knockdown, knockout, and overexpression analyses have shown that c-Jun acts both in a negative and positive regulatory role. Transcriptional activation of cPLA2α occurs through the phosphorylation of c-Jun in conjunction with increased association of C/EBPß with the distal novel enhancer. The association of C/EBPß with the transcriptional activation complex does not require an obvious DNA binding site. These data provide new and important contributions to the understanding of cPLA2α regulation at the transcriptional level, with implications for eicosanoid metabolism, cellular signaling, and disease pathogenesis.


Subject(s)
Cytokines/metabolism , Enhancer Elements, Genetic/genetics , Gene Expression Regulation , Group IV Phospholipases A2/genetics , Cells, Cultured , Group IV Phospholipases A2/biosynthesis , Humans , Real-Time Polymerase Chain Reaction
15.
J Neurotrauma ; 30(13): 1161-9, 2013 Jul 01.
Article in English | MEDLINE | ID: mdl-23409698

ABSTRACT

The goal of this project was to determine whether biochemical markers of brain damage can be used to diagnose and assess the severity of injury in a rat model of penetrating ballistic-like brain injury (PBBI). To determine the relationship between injury magnitude and biomarker levels, rats underwent three discrete PBBI severity levels defined by the magnitude of the ballistic component of the injury, calibrated to equal 5%, 10%, or 12.5% of total rat brain volume. Cortex, cerebrospinal fluid (CSF), and blood were collected at multiple time points. Levels of three biomarkers (αII-spectrin breakdown product [SBDP150], glial fibrillary acidic protein [GFAP], and ubiquitin C-terminal hydrolase-L1 [UCH-L1]), were measured using quantitative immunoblotting and/or enzyme-linked immunosorbent assays. In injured cortex, SBDP150 and GFAP levels were increased significantly over controls. Cortical SBDP150 was elevated at 1 day but not 7 days, and GFAP at 7 days but not 1 day. At their respective time points, mean levels of SBDP150 and GFAP biomarkers in the cortex rose stepwise as injury magnitude increased. In the CSF, increasing severity of PBBI was associated with increasing concentrations of both neuronal and glial biomarkers acutely at 1 day after injury, but no trends were observed at 7 days. In plasma, SBDP150 was elevated at 5 min after 10% PBBI and at 6 h after 12.5% PBBI. UCH-L1 levels in plasma were elevated acutely at 5 min post-injury reflecting injury severity and rapidly decreased within 2 h. Overall, our results support the conclusion that biomarkers are effective indicators of brain damage after PBBI and may also aid in the assessment of injury magnitude.


Subject(s)
Biomarkers/analysis , Glial Fibrillary Acidic Protein/analysis , Head Injuries, Penetrating/metabolism , Spectrin/analysis , Ubiquitin Thiolesterase/analysis , Animals , Disease Models, Animal , Enzyme-Linked Immunosorbent Assay , Immunoblotting , Male , Rats , Rats, Sprague-Dawley
16.
J Cyst Fibros ; 12(3): 258-65, 2013 May.
Article in English | MEDLINE | ID: mdl-22985691

ABSTRACT

BACKGROUND: Allergic bronchopulmonary aspergillosis (ABPA) is a complicating factor in cystic fibrosis (CF), affecting 2-15% of patients. We hypothesized that sensitization/challenge of CFTR(-/-) mice with an Aspergillus fumigatus (Af) extract will affect eicosanoid pathway gene expression, impacting ABPA and CF. METHODS: FABP-hCFTR(+/-)-CFTR(-/-) mice were sensitized/challenged with an Af extract and gene expression of lung mRNA was evaluated for >40 genes, with correlative data in human CF (IB3.1) and CFTR-corrected (S9) bronchoepithelial cell lines. RESULTS: Pla2g4c, Pla2g2c, Pla2g2d and Pla2g5 were induced in response to Af in CFTR(-/-) mice. Interestingly, PLA2G2D was induced by LPS, IL-2, IL-6, IL-13, and Af only in CFTR-deficient human IB3.1 cells. Prostanoid gene expression was relatively constant, however, several 12/15-lipoxygenase genes were induced in response to Af. Numerous cytokines also caused differential expression of ALOX15 only in IB3.1 cells. CONCLUSIONS: The distinct regulation of PLA2G4C, PLA2G2D and ALOX15 genes in Aspergillus sensitization and/or cystic fibrosis could provide new insights into diagnosis and treatment of ABPA and CF.


Subject(s)
Aspergillosis, Allergic Bronchopulmonary/genetics , Cystic Fibrosis Transmembrane Conductance Regulator/deficiency , Cystic Fibrosis/genetics , Hypersensitivity/genetics , Inflammation/genetics , Animals , Cells, Cultured , Gene Expression Regulation , Humans , Mice , Mice, Inbred C57BL
17.
Biomark Insights ; 7: 71-9, 2012.
Article in English | MEDLINE | ID: mdl-22798722

ABSTRACT

After traumatic brain injury (TBI), glial fibrillary acidic protein (GFAP) and other brain-derived proteins and their breakdown products are released into biofluids such as CSF and blood. Recently, a sandwich ELISA was constructed that measured GFAP concentrations in CSF or serum from human mild-moderate TBI patients. The goals of the present study were to characterize the same two antibodies used in this ELISA, and to determine which GFAP bands are detected by this antibody combination. Here, both antibodies recognized GFAP specifically in human brain and post-TBI CSF in a cluster of bands ranging from 50-38 kDa, that resembled bands from calpain-cleaved GFAP. By immunoprecipitation, the anti-GFAP Capture antibody recovered full length GFAP and its breakdown products from human brain lysate and post-TBI CSF. These findings demonstrate that the anti-GFAP ELISA antibodies non-preferentially detect intact GFAP and GFAP breakdown products, underscoring their utility for detecting brain injury in human patients.

18.
Biochem J ; 443(2): 561-71, 2012 Apr 15.
Article in English | MEDLINE | ID: mdl-22260630

ABSTRACT

The studies of PGE2 (prostaglandin E2) biosynthesis have focused primarily on the role of cyclo-oxygenases. Efforts have shifted towards the specific PGE2 terminal synthases, particularly mPGES-1 (microsomal PGE synthase 1), which has emerged as the crucial inducible synthase with roles in pain, cancer and inflammation. mPGES-1 is induced by pro-inflammatory cytokines with studies focusing on the proximal promoter, mediated specifically through Egr-1 (early growth-response factor 1). Numerous studies demonstrate that the mPGES-1 promoter (PTGES) alone cannot account for the level of IL-1ß (interleukin 1ß) induction. We identified two DNase I-hypersensitive sites within the proximal promoter near the Egr-1 element and a novel distal site near -8.6 kb. Functional analysis of the distal site revealed two elements that co-operate with basal promoter expression and a stimulus-dependent enhancer. A specific binding site for C/EBPß (CCAAT/enhancer-binding protein ß) in the enhancer was directly responsible for inducible enhancer activity. ChIP (chromatin immunoprecipitation) analysis demonstrated constitutive Egr-1 binding to the promoter and induced RNA polymerase II and C/EBPß binding to the promoter and enhancer respectively. Knockout/knockdown studies established a functional role for C/EBPß in mPGES-1 gene regulation and the documented interaction between Egr-1 and C/EBPß highlights the proximal promoter co-operation with a novel distal enhancer element in regulating inducible mPGES-1 expression.


Subject(s)
CCAAT-Enhancer-Binding Protein-beta/metabolism , Interleukin-1beta/metabolism , Intramolecular Oxidoreductases/metabolism , Animals , Base Sequence , CCAAT-Enhancer-Binding Protein-beta/deficiency , Cells, Cultured , Gene Expression Regulation, Enzymologic , Humans , Intramolecular Oxidoreductases/genetics , Mice , Mice, Knockout , Promoter Regions, Genetic , Prostaglandin-E Synthases , RNA Polymerase II/metabolism , RNA, Messenger/genetics , Rats
19.
Biochem J ; 442(1): 127-37, 2012 Feb 15.
Article in English | MEDLINE | ID: mdl-22082005

ABSTRACT

Airway inflammation in allergen-induced asthma is associated with eicosanoid release. These bioactive lipids exhibit anti- and pro-inflammatory activities with relevance to pulmonary pathophysiology. We hypothesized that sensitization/challenge using an extract from the ubiquitous fungus Aspergillus fumigatus in a mouse model of allergic asthma would result in altered phospholipase gene expression, thus modulating the downstream eicosanoid pathway. We observed the most significant induction in the group IVC PLA2 (phospholipase A2) [also known as cPLA2γ (cytosolic PLA2γ) or PLA2G4C]. Our results infer that A. fumigatus extract can induce cPLA2γ levels directly in eosinophils, whereas induction in lung epithelial cells is most likely to be a consequence of TNFα (tumour necrosis factor α) secretion by A. fumigatus-activated macrophages. The mechanism of TNFα-dependent induction of cPLA2γ gene expression was elucidated through a combination of promoter deletions, ChIP (chromatin immunoprecipitation) and overexpression studies in human bronchoepithelial cells, leading to the identification of functionally relevant CRE (cAMP-response element), NF-κB (nuclear factor κB) and E-box promoter elements. ChIP analysis demonstrated that RNA polymerase II, ATF-2 (activating transcription factor 2)-c-Jun, p65-p65 and USF (upstream stimulating factor) 1-USF2 complexes are recruited to the cPLA2γ enhancer/promoter in response to TNFα, with overexpression and dominant-negative studies implying a strong level of co-operation and interplay between these factors. Overall, our results link cytokine-mediated alterations in cPLA2γ gene expression with allergic asthma and outline a complex regulatory mechanism.


Subject(s)
Aspergillus fumigatus/immunology , Asthma/genetics , Group IV Phospholipases A2/biosynthesis , Tumor Necrosis Factor-alpha/pharmacology , Activating Transcription Factor 2/metabolism , Animals , Asthma/immunology , Cell Line , Enzyme Induction , Gene Expression Regulation/drug effects , Humans , Lung/cytology , Lung/drug effects , Lung/metabolism , Mice , Mice, Inbred C57BL , Transcription Factors/biosynthesis , Tumor Necrosis Factor-alpha/physiology
20.
Cell Signal ; 23(12): 1944-51, 2011 Dec.
Article in English | MEDLINE | ID: mdl-21771656

ABSTRACT

Cytosolic phospholipase A(2)α (cPLA(2)α) is the most widely studied member of the Group IV PLA(2) family. The enzyme is Ca(2+)-dependent with specificity for phospholipid substrates containing arachidonic acid. As the pinnacle of the arachidonic acid pathway, cPLA(2)α has a primary role in the biosynthesis of a diverse family of eicosanoid metabolites, with potent physiological, inflammatory and pathological consequences. cPLA(2)α activity is regulated by pro-inflammatory stimuli through pathways involving increased intracellular Ca(2+) levels, phosphorylation coupled to increased enzymatic activity and de novo gene transcription. This study addresses the signal transduction pathways for protein phosphorylation and gene induction following IL-1ß stimulation in human fetal lung fibroblasts. Our results utilizing both inhibitors and kinase-deficient cells demonstrate that cPLA(2)α is phosphorylated within 10min of IL-1ß treatment, an event requiring p38 MAPK as well as the upstream kinase, MKK3/MKK6. Inhibition of p38 MAPK also blocks the phosphorylation of a downstream, nuclear kinase, MSK-1. Our results further demonstrate that the activities of both cPLA(2)α and a downstream lipoxygenase (15-LOX2) are required for IL-1ß-dependent induction of cPLA(2)α mRNA expression. Overall, these data support an MKK3/MKK6→p38 MAPK→MSK-1→cPLA(2)α→15-LOX2-dependent, positive feedback loop where a protein's enzymatic activity is required to regulate its own gene induction by a pro-inflammatory stimulus.


Subject(s)
Arachidonate 15-Lipoxygenase/metabolism , Feedback, Physiological , Group IV Phospholipases A2/metabolism , Interleukin-1beta/physiology , MAP Kinase Signaling System , Transcriptional Activation , Animals , Cell Line , Enzyme Activation , Fluorenes/pharmacology , Gene Expression , Gene Knockout Techniques , Humans , Imidazoles/pharmacology , Interleukin-1beta/pharmacology , Isoenzymes/antagonists & inhibitors , Isoenzymes/genetics , Isoenzymes/metabolism , Lipoxygenase Inhibitors/pharmacology , Luteolin/pharmacology , MAP Kinase Kinase 3/genetics , MAP Kinase Kinase 3/metabolism , MAP Kinase Kinase 6/genetics , MAP Kinase Kinase 6/metabolism , Masoprocol/pharmacology , Mice , Phosphorylation , Pyridines/pharmacology , Ribosomal Protein S6 Kinases, 90-kDa/metabolism , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/genetics , p38 Mitogen-Activated Protein Kinases/metabolism
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