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1.
Front Immunol ; 15: 1374437, 2024.
Article in English | MEDLINE | ID: mdl-38711507

ABSTRACT

Mycobacterium avium complex (MAC) is a non-tuberculous mycobacterium widely distributed in the environment. Even though MAC infection is increasing in older women and immunocompromised patients, to our knowledge there has been no comprehensive analysis of the MAC-infected host-cell transcriptome-and particularly of long non-coding RNAs (lncRNAs). By using in vitro-cultured primary mouse bone-marrow-derived macrophages (BMDMs) and Cap analysis of gene expression, we analyzed the transcriptional and kinetic landscape of macrophage genes, with a focus on lncRNAs, during MAC infection. MAC infection of macrophages induced the expression of immune/inflammatory response genes and other genes similar to those involved in M1 macrophage activation, consistent with previous reports, although Nos2 (M1 activation) and Arg1 (M2 activation) had distinct expression profiles. We identified 31 upregulated and 30 downregulated lncRNA promoters corresponding respectively to 18 and 26 lncRNAs. Upregulated lncRNAs were clustered into two groups-early and late upregulated-predicted to be associated with immune activation and the immune response to infection, respectively. Furthermore, an Ingenuity Pathway Analysis revealed canonical pathways and upstream transcription regulators associated with differentially expressed lncRNAs. Several differentially expressed lncRNAs reported elsewhere underwent expressional changes upon M1 or M2 preactivation and subsequent MAC infection. Finally, we showed that expressional change of lncRNAs in MAC-infected BMDMs was mediated by toll-like receptor 2, although there may be other mechanisms that sense MAC infection. We identified differentially expressed lncRNAs in MAC-infected BMDMs, revealing diverse features that imply the distinct roles of these lncRNAs in MAC infection and macrophage polarization.


Subject(s)
Gene Expression Profiling , Macrophages , Mycobacterium avium Complex , Mycobacterium avium-intracellulare Infection , RNA, Long Noncoding , Transcriptome , RNA, Long Noncoding/genetics , Animals , Macrophages/immunology , Macrophages/microbiology , Macrophages/metabolism , Mycobacterium avium Complex/immunology , Mycobacterium avium Complex/genetics , Mice , Mycobacterium avium-intracellulare Infection/immunology , Mycobacterium avium-intracellulare Infection/genetics , Mycobacterium avium-intracellulare Infection/microbiology , Macrophage Activation/genetics , Macrophage Activation/immunology , Mice, Inbred C57BL , Cells, Cultured , Gene Expression Regulation
2.
IDCases ; 36: e01958, 2024.
Article in English | MEDLINE | ID: mdl-38681073

ABSTRACT

We present the case of a 66-year-old woman undergoing chronic dialysis who developed pneumonia and enteritis after being infected with COVID-19 and had severe wall motion reduction similar to a left ventricular aneurysm. There was concern that the condition might worsen due to left ventricular wall thinning and curious wall motion abnormalities, but echocardiography one month later showed normalization. After four months, simultaneous binuclear myocardial scintigraphy of thallium and BMIPP showed that the mismatch had disappeared. We considered that there may be other factors specific to COVID-19 infection in addition to the stress associated with infection and reviewed the literature.

3.
J Cardiothorac Surg ; 18(1): 275, 2023 Oct 07.
Article in English | MEDLINE | ID: mdl-37805478

ABSTRACT

Left ventricular free wall rupture (LVFWR) is a rare but fatal complication of acute myocardial infarction (AMI). An 81-year-old female patient with several cardiovascular risk factors presented to the emergency department with symptoms of developing a chronic stomachache and cold sweat. An echocardiograph showed wall motion abnormalities from the lateral to posterior wall, as well as pericardial effusion containing clots of up to 17 mm in the posterior wall that indicated LVFWR after AMI. Although she was conscious after being brought to the initial care unit, she suddenly lost consciousness and fell into electromechanical dissociation (EMD). Endotracheal intubation was immediately initiated and her pericardial drainage and intra aortic balloon pump (IABP) placement, and hemodynamics recovered. Although she had 100% obstruction in the left circumflex artery (LCX) #12 on coronary angiography (CAG), she was discharged to the Intensive Care Unit (ICU) without percutaneous coronary intervention (PCI). Conservative treatment such as intubation, sedation, pericardiocentesis and strict blood pressure management as well as treatment by IABP long-term support led to the patient being uneventfully discharged after 60 days.


Subject(s)
Heart Rupture , Myocardial Infarction , Percutaneous Coronary Intervention , Humans , Female , Aged, 80 and over , Percutaneous Coronary Intervention/adverse effects , Conservative Treatment/adverse effects , Myocardial Infarction/complications , Myocardial Infarction/therapy , Myocardial Infarction/diagnosis , Heart Rupture/diagnosis , Echocardiography
4.
Heliyon ; 9(6): e16512, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37255981

ABSTRACT

Myocarditis is often reported as a complication of COVID-19 infection or post-vaccination, but there are few reports of "myocarditis for Post-acute COVID-19 syndrome", and many unknowns still remain. Apart from that, an association between COVID-19 infection and dermatomyositis has also been reported. We describe the clinical presentation of acute myocarditis in a patient who had developed COVID-19 syndrome one-month earlier. A healthy 49-year-old man experienced typical COVID-19 symptoms. Thirty-two days later, he was admitted because of fever and severe fatigue, chest pain and bradycardia. Blood tests showed major inflammation. PCR for SARS-CoV-2 on nasopharyngeal swab (ID NOW™) was positive, but diagnosed as a previous infection due to a high CT value. Because of haemodynamic worsening with both an increase in cardiac troponin I and NT-pro BNP levels and reduced wall motion on echocardiography, acute myocarditis was suspected. Myocardial biopsy revealed severe lymphocytic infiltration and interstitial edema between myocardial fibers. These findings led to the diagnosis of fulminant myocarditis. Interestingly, myocardium was also stained with human myxovirus resistance protein 1 (MxA). We consider that there may be an aspect of "dermatomyositis-like myocarditis with SARS-CoV-2" in our case. This is the first case of fulminant myocarditis for Post-acute COVID-19 syndrome in which diagnosis of active myocarditis was proven by pathological examination following myocardial biopsy and strong association with dermatomyositis was suggested pathologically.

5.
Sci Data ; 10(1): 93, 2023 02 14.
Article in English | MEDLINE | ID: mdl-36788249

ABSTRACT

Hepatocytes are a major parenchymal cell type in the liver and play an essential role in liver function. Hepatocyte-like cells can be differentiated in vitro from induced pluripotent stem cells (iPSCs) via definitive endoderm (DE)-like cells and hepatoblast-like cells. Here, we explored the in vitro differentiation time-course of hepatocyte-like cells. We performed methylome and transcriptome analyses for hepatocyte-like cell differentiation. We also analyzed DE-like cell differentiation by methylome, transcriptome, chromatin accessibility, and GATA6 binding profiles, using finer time-course samples. In this manuscript, we provide a detailed description of the dataset and the technical validations. Our data may be valuable for the analysis of the molecular mechanisms underlying hepatocyte and DE differentiations.


Subject(s)
Cell Differentiation , Induced Pluripotent Stem Cells , Humans , Endoderm , Hepatocytes , Liver
6.
Commun Biol ; 5(1): 414, 2022 05 04.
Article in English | MEDLINE | ID: mdl-35508708

ABSTRACT

Hepatocytes are the dominant cell type in the human liver, with functions in metabolism, detoxification, and producing secreted proteins. Although gene regulation and master transcription factors involved in the hepatocyte differentiation have been extensively investigated, little is known about how the epigenome is regulated, particularly the dynamics of DNA methylation and the critical upstream factors. Here, by examining changes in the transcriptome and the methylome using an in vitro hepatocyte differentiation model, we show putative DNA methylation-regulating transcription factors, which are likely involved in DNA demethylation and maintenance of hypo-methylation in a differentiation stage-specific manner. Of these factors, we further reveal that GATA6 induces DNA demethylation together with chromatin activation in a binding-site-specific manner during endoderm differentiation. These results provide an insight into the spatiotemporal regulatory mechanisms exerted on the DNA methylation landscape by transcription factors and uncover an epigenetic role for transcription factors in early liver development.


Subject(s)
DNA Methylation , GATA6 Transcription Factor , Cell Differentiation/genetics , Chromatin Immunoprecipitation , GATA6 Transcription Factor/genetics , GATA6 Transcription Factor/metabolism , Hepatocytes/metabolism , Humans
7.
Expert Opin Biol Ther ; 18(sup1): 89-94, 2018 07.
Article in English | MEDLINE | ID: mdl-30063859

ABSTRACT

OBJECTIVES: Prothymosin α (ProTα) was reported to inhibit the neuronal necrosis by facilitating the plasma membrane localization of endocytosed glucose transporter 1/4 through an activation of putative Gi-coupled receptor. The present study aims to identify a novel ProTα target, which may lead to an activation of Gi-coupled receptor. METHODS: We used Gi-rich lipid rafts fraction of retinal cell line N18-RE-105 cells for affinity cross-linking. The biological confirmation that F0/F1 ATPase is a target protein complex was performed by cell-free experiments using ELISA-based binding assay, surface plasmon resonance assay and quartz crystal microbalance assay, and cell-based experiments to measure extracellular ATP level in the HUVECs culture. RESULTS: From the cross-linking study and above-mentioned protein-protein interaction assays, ATP5A1 and ATP5B, F1 ATPase subunits were found to ProTα binding target proteins. In the culture of HUVEC cells, furthermore, ProTα increased the extracellular ATP levels in a reversible manner by anti-ATP5A1- and ATP5B-antibodies. CONCLUSION: The present study suggests that ProTα may activate ecto-F0/F1 ATPase and produced ATP. This study leads to next subjects whether produced ATP and its metabolites, ADP or adenosine may activate corresponding Gi-coupled receptors.


Subject(s)
Adenosine Triphosphatases/metabolism , Proton-Translocating ATPases/metabolism , Receptors, Immunologic/metabolism , Animals , Carrier Proteins/metabolism , Cells, Cultured , Cross-Linking Reagents/chemistry , Human Umbilical Vein Endothelial Cells , Humans , Mice , Necrosis , Protein Binding , Protein Precursors/metabolism , Rats , Rats, Inbred F344 , Signal Transduction/physiology , Thymosin/analogs & derivatives , Thymosin/metabolism
8.
Nihon Yakurigaku Zasshi ; 151(1): 15-19, 2018.
Article in Japanese | MEDLINE | ID: mdl-29321391

ABSTRACT

Prothymosin alpha (ProTα) has been identified as an anti-necrotic factor from the conditioned medium of primary cultured of rat cortical neurons under the serum-free starving condition. ProTα is released in a non-vesicular manner from neurons or astrocytes by the help of cargo protein S100A13. Thus released ProTα is found to have robustness roles in the brain under the condition of neuronal necrosis or apoptosis. ProTα inhibits necrosis by plasma membrane-translocation of glucose transporters endocytosed by ischemia/starving stress, through an activation of unidentified G protein-coupled receptor and protein kinase Cß. In the cerebral or retinal ischemia model, systemic injection of ProTα protects brain or retina from ischemic damages by converting necrosis to apoptosis, which is in turn blocked by neurotrophic factors. In the retinal ischemia model, ProTα prevents the damages by another mechanism through toll-like receptor 4 (TLR4) and downstream TRIF signaling. The direct interaction between ProTα and TLR4/MD2 is also evidenced by the study of molecular dynamics and protein-protein interaction. All these findings indicate that ProTα could be called a cytoprotective member of damage-associated molecular patterns (DAMPs) or alarmins. ProTα and its modified peptide fragment, NEVDQE (P6Q) show the vasculoprotective actions by itself in a model of cerebral ischemia as well as neuroprotective actions. The concomitant administration of these peptides abolishes the cerebral hemorrhage induced tissue plasminogen activator (tPA), which is treated late after cerebral ischemia models. Thus, ProTα and P6Q seem to have promising therapeutic potencies to directly protect neurons and inhibit the hemorrhage by late treatment with tPA against stroke.


Subject(s)
Alarmins/metabolism , Protein Precursors/metabolism , Thymosin/analogs & derivatives , Animals , Apoptosis , Drug Design , Humans , Necrosis , Signal Transduction , Thymosin/metabolism
9.
Epigenetics Chromatin ; 10(1): 60, 2017 12 08.
Article in English | MEDLINE | ID: mdl-29221486

ABSTRACT

BACKGROUND: DNA methylation is a fundamental epigenetic modification that is involved in many biological systems such as differentiation and disease. We and others recently showed that some transcription factors (TFs) are involved in the site-specific determination of DNA demethylation in a binding site-directed manner, although the reports of such TFs are limited. RESULTS: Here, we develop a screening system to identify TFs that induce binding site-directed DNA methylation changes. The system involves the ectopic expression of target TFs in model cells followed by DNA methylome analysis and overrepresentation analysis of the corresponding TF binding motif at differentially methylated regions. It successfully identified binding site-directed demethylation of SPI1, which is known to promote DNA demethylation in a binding site-directed manner. We extended our screening system to 15 master TFs involved in cellular differentiation and identified eight novel binding site-directed DNA demethylation-inducing TFs (RUNX3, GATA2, CEBPB, MAFB, NR4A2, MYOD1, CEBPA, and TBX5). Gene ontology and tissue enrichment analysis revealed that these TFs demethylate genomic regions associated with corresponding biological roles. We also describe the characteristics of binding site-directed DNA demethylation induced by these TFs, including the targeting of highly methylated CpGs, local DNA demethylation, and the overlap of demethylated regions between TFs of the same family. CONCLUSIONS: Our results show the usefulness of the developed screening system for the identification of TFs that induce DNA demethylation in a site-directed manner.


Subject(s)
Demethylation , Transcription Factors/metabolism , Binding Sites , DNA Methylation
11.
BMC Mol Biol ; 18(1): 9, 2017 04 04.
Article in English | MEDLINE | ID: mdl-28376714

ABSTRACT

BACKGROUND: SPI1 is an essential transcription factor (TF) for the hematopoietic lineage, in which its expression is tightly controlled through a -17-kb upstream regulatory region and a promoter region. Both regulatory regions are demethylated during hematopoietic development, although how the change of DNA methylation status is performed is still unknown. RESULTS: We found that the ectopic overexpression of RUNX1 (another key TF in hematopoiesis) in HEK-293T cells induces almost complete DNA demethylation at the -17-kb upstream regulatory region and partial but significant DNA demethylation at the proximal promoter region. This DNA demethylation occurred in mitomycin-C-treated nonproliferating cells at both regulatory regions, suggesting active DNA demethylation. Furthermore, ectopic RUNX1 expression induced significant endogenous SPI1 expression, although its expression level was much lower than that of natively SPI1-expressing monocyte cells. CONCLUSIONS: These results suggest the novel role of RUNX1 as an inducer of DNA demethylation at the SPI1 regulatory regions, although the mechanism of RUNX1-induced DNA demethylation remains to be explored.


Subject(s)
Core Binding Factor Alpha 2 Subunit/metabolism , DNA Methylation , DNA Replication , Proto-Oncogene Proteins/genetics , Trans-Activators/genetics , Base Sequence , Cell Line , Core Binding Factor Alpha 2 Subunit/genetics , Gene Expression Regulation , Humans , Promoter Regions, Genetic , Up-Regulation
12.
Blood Adv ; 1(20): 1699-1711, 2017 Sep 12.
Article in English | MEDLINE | ID: mdl-29296817

ABSTRACT

RUNX1 is an essential master transcription factor in hematopoietic development and plays important roles in immune functions. Although the gene regulatory mechanism of RUNX1 has been characterized extensively, the epigenetic role of RUNX1 remains unclear. Here, we demonstrate that RUNX1 contributes DNA demethylation in a binding site-directed manner in human hematopoietic cells. Overexpression analysis of RUNX1 showed the RUNX1-binding site-directed DNA demethylation. The RUNX1-mediated DNA demethylation was also observed in DNA replication-arrested cells, suggesting an involvement of active demethylation mechanism. Coimmunoprecipitation in hematopoietic cells showed physical interactions between RUNX1 and DNA demethylation machinery enzymes TET2, TET3, TDG, and GADD45. Further chromatin immunoprecipitation sequencing revealed colocalization of RUNX1 and TET2 in the same genomic regions, indicating recruitment of DNA demethylation machinery by RUNX1. Finally, methylome analysis revealed significant overrepresentation of RUNX1-binding sites at demethylated regions during hematopoietic development. Collectively, the present data provide evidence that RUNX1 contributes site specificity of DNA demethylation by recruitment of TET and other demethylation-related enzymes to its binding sites in hematopoietic cells.

13.
PLoS One ; 11(8): e0160459, 2016.
Article in English | MEDLINE | ID: mdl-27483142

ABSTRACT

Transcriptional regulatory network (TRN) reconstitution and deconstruction occur simultaneously during reprogramming; however, it remains unclear how the starting and targeting TRNs regulate the induction and suppression of peripheral genes. Here we analyzed the regulation using direct cell reprogramming from human dermal fibroblasts to monocytes as the platform. We simultaneously deconstructed fibroblastic TRN and reconstituted monocytic TRN; monocytic and fibroblastic gene expression were analyzed in comparison with that of fibroblastic TRN deconstruction only or monocytic TRN reconstitution only. Global gene expression analysis showed cross-regulation of TRNs. Detailed analysis revealed that knocking down fibroblastic TRN positively affected half of the upregulated monocytic genes, indicating that intrinsic fibroblastic TRN interfered with the expression of induced genes. In contrast, reconstitution of monocytic TRN showed neutral effects on the majority of fibroblastic gene downregulation. This study provides an explicit example that demonstrates how two networks together regulate gene expression during cell reprogramming processes and contributes to the elaborate exploration of TRNs.


Subject(s)
Cellular Reprogramming , Fibroblasts/metabolism , Gene Regulatory Networks , Monocytes/metabolism , Transcription, Genetic , Cell Line , Fibroblasts/cytology , Gene Expression Profiling , Gene Expression Regulation , Genetic Vectors/chemistry , Genetic Vectors/metabolism , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , LIM-Homeodomain Proteins/genetics , LIM-Homeodomain Proteins/metabolism , Lentivirus/genetics , Lentivirus/metabolism , Microarray Analysis , Monocytes/cytology , Repressor Proteins/genetics , Repressor Proteins/metabolism , Skin/cytology , Skin/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Transduction, Genetic , Twist-Related Protein 1/genetics , Twist-Related Protein 1/metabolism
14.
J Pharmacol Sci ; 132(1): 100-104, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27543170

ABSTRACT

Prothymosin alpha (ProTα) suppresses stress-induced necrosis of cultured cortical neurons. As neuroprotection alone could not explain the long-lasting protective actions against cerebral ischemia by ProTα, we further examined whether ProTα, in addition to neuroprotective effects, has other anti-ischemic activities. When recombinant mouse ProTα (rmProTα) at 0.3 mg/kg was intravenously (i.v.) given 2 h after the start of tMCAO, all mice survived for more than 14 days. In evaluation of CD31- and tomato lectin-labeling as well as IgG and Evans blue leakage, rmProTα treatment (0.1 mg/kg) largely blocked ischemia-induced vascular damages. Therefore, rmProTα has novel beneficial effects against ischemia-induced brain damage through vascular mechanisms.


Subject(s)
Infarction, Middle Cerebral Artery/drug therapy , Neuroprotective Agents/therapeutic use , Protein Precursors/therapeutic use , Thymosin/analogs & derivatives , Animals , Blood Vessels/drug effects , Blood Vessels/pathology , Brain/drug effects , Brain/pathology , Infarction, Middle Cerebral Artery/pathology , Male , Mice, Inbred C57BL , Thymosin/therapeutic use
15.
Anal Chem ; 87(13): 6483-6, 2015 Jul 07.
Article in English | MEDLINE | ID: mdl-26084326

ABSTRACT

A micro ion extractor (MIE) was developed for trace anion determination by ion chromatography-mass spectrometry from a single drop (25 µL) of whole blood without pretreatment. Target analytes were iodide and thiocyanate, which play key roles in thyroid hormone production. Whole blood (25 µL) was pipetted from an earlobe or finger prick and placed in the 16 µL cavity of the device. A reproducible fraction of iodide and thiocyanate was transferred through a membrane to an acceptor solution layer by electromigration for 60 s. An isolator solution layer and a cation exchange membrane is provided between the acceptor and the anode to prevent gas formation or redox processes in the acceptor. The acceptor contents are transferred online to the ion chromatograph. Isolator solution composition and applied voltage were optimized. Recoveries from samples from 16 different volunteers of both sexes and differing ages were the same within ±10% relative standard deviation. Dietary effects on blood iodide and thiocyanate levels are reported. The very low sample requirement permitted multiple sample collections per day. The MIE device is expected to be useful for clinical studies that require several/many temporally spaced blood samples by keeping the invasive nature of blood collection as minimal as possible.


Subject(s)
Blood Chemical Analysis , Diet , Humans , Iodides/blood , Smoking , Thiocyanates/blood
16.
Science ; 344(6185): 760-4, 2014 May 16.
Article in English | MEDLINE | ID: mdl-24833394

ABSTRACT

A switchlike response in nuclear factor-κB (NF-κB) activity implies the existence of a threshold in the NF-κB signaling module. We show that the CARD-containing MAGUK protein 1 (CARMA1, also called CARD11)-TAK1 (MAP3K7)-inhibitor of NF-κB (IκB) kinase-ß (IKKß) module is a switch mechanism for NF-κB activation in B cell receptor (BCR) signaling. Experimental and mathematical modeling analyses showed that IKK activity is regulated by positive feedback from IKKß to TAK1, generating a steep dose response to BCR stimulation. Mutation of the scaffolding protein CARMA1 at serine-578, an IKKß target, abrogated not only late TAK1 activity, but also the switchlike activation of NF-κB in single cells, suggesting that phosphorylation of this residue accounts for the feedback.


Subject(s)
CARD Signaling Adaptor Proteins/metabolism , Guanylate Cyclase/metabolism , I-kappa B Kinase/metabolism , MAP Kinase Kinase Kinases/metabolism , NF-kappa B/agonists , Receptors, Antigen, B-Cell/metabolism , Animals , B-Lymphocytes/metabolism , CARD Signaling Adaptor Proteins/genetics , Cell Line , Chickens , Feedback, Physiological , Guanylate Cyclase/genetics , MAP Kinase Kinase Kinases/genetics , Mice , Mice, Knockout , Mutation , Phosphorylation , Receptors, Antigen, B-Cell/genetics , Serine/genetics , Serine/metabolism , Signal Transduction
17.
Nature ; 507(7493): 455-461, 2014 Mar 27.
Article in English | MEDLINE | ID: mdl-24670763

ABSTRACT

Enhancers control the correct temporal and cell-type-specific activation of gene expression in multicellular eukaryotes. Knowing their properties, regulatory activity and targets is crucial to understand the regulation of differentiation and homeostasis. Here we use the FANTOM5 panel of samples, covering the majority of human tissues and cell types, to produce an atlas of active, in vivo-transcribed enhancers. We show that enhancers share properties with CpG-poor messenger RNA promoters but produce bidirectional, exosome-sensitive, relatively short unspliced RNAs, the generation of which is strongly related to enhancer activity. The atlas is used to compare regulatory programs between different cells at unprecedented depth, to identify disease-associated regulatory single nucleotide polymorphisms, and to classify cell-type-specific and ubiquitous enhancers. We further explore the utility of enhancer redundancy, which explains gene expression strength rather than expression patterns. The online FANTOM5 enhancer atlas represents a unique resource for studies on cell-type-specific enhancers and gene regulation.


Subject(s)
Atlases as Topic , Enhancer Elements, Genetic/genetics , Gene Expression Regulation/genetics , Molecular Sequence Annotation , Organ Specificity , Cell Line , Cells, Cultured , Cluster Analysis , Genetic Predisposition to Disease/genetics , HeLa Cells , Humans , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Transcription Initiation Site , Transcription Initiation, Genetic
18.
Int Immunol ; 21(4): 393-401, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19223432

ABSTRACT

The serine/threonine kinase MEKK3, also known as mitogen-activated protein kinase kinase kinase 3, is a critical activator of the transcription factor NF-kappaB in innate immunity. However, the physiological function of MEKK3 in adaptive immunity is unclear. Here we report that following TCR signaling, MEKK3 positively regulated the kinase, IkappaB kinase, leading to NF-kappaB activation. T cells lacking MEKK3 were defective in TCR-induced and cytokine-induced responses. Furthermore, T cell-specific deletion of MEKK3 resulted in reduced numbers of thymocytes and peripheral T cells. Thus, our results provide genetic evidence that MEKK3 plays a crucial role in adaptive immunity.


Subject(s)
I-kappa B Kinase/metabolism , Lymphocyte Activation , MAP Kinase Kinase Kinase 3/metabolism , NF-kappa B/metabolism , T-Lymphocytes/immunology , Animals , Cell Proliferation/drug effects , I-kappa B Kinase/immunology , Immunity, Active , Interleukin-2/pharmacology , Interleukin-7/pharmacology , MAP Kinase Kinase Kinase 3/genetics , MAP Kinase Kinase Kinase 3/immunology , Mice , Mice, Inbred C57BL , Mice, Knockout , NF-kappa B/immunology , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , Signal Transduction , T-Lymphocytes/drug effects
19.
J Exp Med ; 204(13): 3285-93, 2007 Dec 24.
Article in English | MEDLINE | ID: mdl-18086859

ABSTRACT

Protein kinase C (PKC) beta has been reported (Shinohara, H., T. Yasuda, Y. Aiba, H. Sanjo, M. Hamadate, H. Watarai, H. Sakurai, and T. Kurosaki. 2005. J. Exp. Med. 202:1423-1431; Sommer, K., B. Guo, J.L. Pomerantz, A.D. Bandaranayake, M.E. Moreno-Garcia, Y.L. Ovechkina, and D.J. Rawlings. 2005. Immunity. 23:561-574) to play a crucial role in B cell receptor (BCR)-mediated IkappaB kinase (IKK) activation through phosphorylation of caspase recruitment domain 11, Bimp3 (CARMA1). However, it remains unclear whether this PKCbeta-mediated phosphorylation accounts fully for the activation status of CARMA1, because involvement of other kinases, such as phosphoinositide 3-kinase-dependent kinase 1, has also been suggested. We show that PKCbeta mediates phosphorylation of CARMA1 on Ser668, which in turn is essential for BCR-mediated CARMA1-Bcl10-mucosal-associated lymphoid tissue 1 (MALT1) association and subsequent IKK activation. Our analyses also demonstrate that the downstream kinase IKKbeta contributes to facilitating formation of the complex CARMA1-Bcl10-MALT1 by mediating phosphorylation of CARMA1. Hence, our data suggest that PKCbeta is crucial for initial activation of IKK. The activated IKKbeta does not merely function as an effector enzyme but also modifies the upstream signaling complex through a feedback mechanism, thereby optimizing the strength and duration of the nuclear factor kappaB signal.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Apoptosis Regulatory Proteins/metabolism , Caspases/metabolism , I-kappa B Kinase/metabolism , Animals , B-Cell CLL-Lymphoma 10 Protein , B-Lymphocytes/metabolism , CARD Signaling Adaptor Proteins/metabolism , Cell Line , Chickens , Gene Deletion , Humans , Immunoprecipitation , Mucosa-Associated Lymphoid Tissue Lymphoma Translocation 1 Protein , Neoplasm Proteins/metabolism , Phosphorylation , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Transfection
20.
Science ; 308(5719): 248-51, 2005 Apr 08.
Article in English | MEDLINE | ID: mdl-15705807

ABSTRACT

The microenvironments of the thymus are generated by thymic epithelial cells (TECs) and are essential for inducing immune self-tolerance or developing T cells. However, the molecular mechanisms that underlie the differentiation of TECs and thymic compartmentalization are not fully understood. Here we show that deficiency in the tumor necrosis factor receptor-associated factor (TRAF) 6 results in disorganized distribution of medullary TECs (mTECs) and the absence of mature mTECs. Engraftment of thymic stroma of TRAF6(-/-) embryos into athymic nude mice induced autoimmunity. Thus, TRAF6 directs the development of thymic stroma and represents a critical point of regulation for self-tolerance and autoimmunity.


Subject(s)
Self Tolerance , TNF Receptor-Associated Factor 6/physiology , Thymus Gland/immunology , Animals , Autoimmunity , Cell Line , Epithelial Cells/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Nude , Organ Culture Techniques , Proto-Oncogene Proteins/physiology , T-Lymphocytes/immunology , TNF Receptor-Associated Factor 6/immunology , Thymus Gland/cytology , Thymus Gland/embryology , Transcription Factor RelB , Transcription Factors/physiology
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