ABSTRACT
Autoimmune diseases, among the most common disorders of young adults, are mediated by genetic and environmental factors. Although CD4+FOXP3+ regulatory T cells (Tregs) play a central role in preventing autoimmunity, the molecular mechanism underlying their dysfunction is unknown. Here, we performed comprehensive transcriptomic and epigenomic profiling of Tregs in the autoimmune disease multiple sclerosis (MS) to identify critical transcriptional programs regulating human autoimmunity. We found that up-regulation of a primate-specific short isoform of PR domain zinc finger protein 1 (PRDM1-S) induces expression of serum and glucocorticoid-regulated kinase 1 (SGK1) independent from the evolutionarily conserved long PRDM1, which led to destabilization of forkhead box P3 (FOXP3) and Treg dysfunction. This aberrant PRDM1-S/SGK1 axis is shared among other autoimmune diseases. Furthermore, the chromatin landscape profiling in Tregs from individuals with MS revealed enriched activating protein-1 (AP-1)/interferon regulatory factor (IRF) transcription factor binding as candidate upstream regulators of PRDM1-S expression and Treg dysfunction. Our study uncovers a mechanistic model where the evolutionary emergence of PRDM1-S and epigenetic priming of AP-1/IRF may be key drivers of dysfunctional Tregs in autoimmune diseases.
Subject(s)
Autoimmunity , Forkhead Transcription Factors , Multiple Sclerosis , Positive Regulatory Domain I-Binding Factor 1 , T-Lymphocytes, Regulatory , T-Lymphocytes, Regulatory/immunology , T-Lymphocytes, Regulatory/metabolism , Humans , Forkhead Transcription Factors/metabolism , Forkhead Transcription Factors/genetics , Positive Regulatory Domain I-Binding Factor 1/metabolism , Positive Regulatory Domain I-Binding Factor 1/genetics , Multiple Sclerosis/genetics , Multiple Sclerosis/immunology , Transcription Factor AP-1/metabolism , Transcription, Genetic , Animals , Chromatin/metabolism , Autoimmune Diseases/genetics , Autoimmune Diseases/immunologyABSTRACT
Transcribed enhancer maps can reveal nuclear interactions underpinning each cell type and connect specific cell types to diseases. Using a 5' single-cell RNA sequencing approach, we defined transcription start sites of enhancer RNAs and other classes of coding and noncoding RNAs in human CD4+ T cells, revealing cellular heterogeneity and differentiation trajectories. Integration of these datasets with single-cell chromatin profiles showed that active enhancers with bidirectional RNA transcription are highly cell type-specific and that disease heritability is strongly enriched in these enhancers. The resulting cell type-resolved multimodal atlas of bidirectionally transcribed enhancers, which we linked with promoters using fine-scale chromatin contact maps, enabled us to systematically interpret genetic variants associated with a range of immune-mediated diseases.
Subject(s)
CD4-Positive T-Lymphocytes , Enhancer Elements, Genetic , Genetic Predisposition to Disease , Transcription Initiation Site , Transcription, Genetic , Humans , CD4-Positive T-Lymphocytes/immunology , Cell Differentiation , Chromatin/metabolism , Chromatin/genetics , Promoter Regions, Genetic , T-Lymphocytes, Helper-Inducer/immunology , Single-Cell Gene Expression Analysis , Atlases as TopicABSTRACT
Gastrointestinal stromal tumors (GISTs) are typically characterized by activating mutations of the KIT proto-oncogene receptor tyrosine kinase (KIT) or platelet-derived growth factor receptor alpha (PDGFRA). Recently, the neurotrophic tyrosine receptor kinase (NTRK) fusion was reported in a small subset of wild-type GIST. We examined trk IHC and NTRK gene expressions in GIST. Pan-trk immunohistochemistry (IHC) was positive in 25 (all 16 duodenal and 9 out of 16 small intestinal GISTs) of 139 cases, and all pan-trk positive cases showed diffuse and strong expression of c-kit. Interestingly, all of these cases showed only trkB but not trkA/trkC expression. Cap analysis of gene expression (CAGE) analysis identified increased number of genes whose promoters were activated in pan-trk/trkB positive GISTs. Imbalanced expression of NTRK2, which suggests the presence of NTRK2 fusion, was not observed in any of trkB positive GISTs, despite higher mRNA expression. TrkB expression was found in duodenal GISTs and more than half of small intestinal GISTs, and this subset of cases showed poor prognosis. However, there was not clear difference in clinical outcomes according to the trkB expression status in small intestinal GISTs. These findings may provide a possible hypothesis for trkB overexpression contributing to the tumorigenesis and aggressive clinical outcome in GISTs of duodenal origin.
Subject(s)
Gastrointestinal Stromal Tumors , Humans , Gastrointestinal Stromal Tumors/genetics , Prognosis , Receptor Protein-Tyrosine Kinases , Proto-Oncogenes , Proto-Oncogene Proteins c-kitABSTRACT
The living body is composed of innumerable fine and complex structures. Although these structures have been studied in the past, a vast amount of information pertaining to them still remains unknown. When attempting to observe these ultra-structures, the use of electron microscopy (EM) has become indispensable. However, conventional EM settings are limited to a narrow tissue area, which can bias observations. Recently, new trends in EM research have emerged, enabling coverage of far broader, nano-scale fields of view for two-dimensional wide areas and three-dimensional large volumes. Moreover, cutting-edge bioimage informatics conducted via deep learning has accelerated the quantification of complex morphological bioimages. Taken together, these technological and analytical advances have led to the comprehensive acquisition and quantification of cellular morphology, which now arises as a new omics science termed 'morphomics'.
Subject(s)
Microscopy, Electron , Microscopy, Electron/methods , Humans , Animals , Imaging, Three-Dimensional/methodsABSTRACT
SUMMARY: The etiology of hyponatremia is assessed based on urine osmolality and sodium. We herein describe a 35-year-old Asian man with pulmonary tuberculosis and perforated duodenal ulcer who presented with hyponatremia with hourly fluctuating urine osmolality ranging from 100 to 600 mosmol/kg, which resembled urine osmolality observed in typical polydipsia and SIADH simultaneously. Further review revealed correlation of body temperature and urine osmolality. Since fever is a known non-osmotic stimulus of ADH secretion, we theorized that hyponatremia in this patient was due to transient ADH secretion due to fever. In our case, empiric exogenous glucocorticoid suppressed transient non-osmotic ADH secretion and urine osmolality showed highly variable concentrations. Transient ADH secretion-related hyponatremia may be underrecognized due to occasional empiric glucocorticoid administration in patients with critical illnesses. Repeatedly monitoring of urine chemistries and interpretation of urine chemistries with careful review of non-osmotic stimuli of ADH including fever is crucial in recognition of this etiology. LEARNING POINTS: Hourly fluctuations in urine osmolality can be observed in patients with fever, which is a non-osmotic stimulant of ADH secretion. Repeated monitoring of urine chemistries aids in the diagnosis of the etiology underlying hyponatremia, including fever, in patients with transient ADH secretion. Glucocorticoid administration suppresses ADH secretion and improves hyponatremia even in the absence of adrenal insufficiency; the etiology of hyponatremia should be determined carefully in these patients.
ABSTRACT
BACKGROUND: The word "sign" refers to important physical findings or observations that are useful in diagnosis; however, there are no scientific reviews of "signs." The aim of this paper was to list and review these terms using a bibliographic approach. METHODS: We performed a title search of "sign" using a bibliographic search and review approach in MEDLINE and EMBASE. RESULTS: We detected 398 papers including 217 medical signs in cardiology. CONCLUSIONS: This is the first literature review of eponyms specifically for signs using a bibliographic method, which is useful for the discussion of the appropriateness of eponyms.
ABSTRACT
A 65-year-old Japanese man presented with acute myocardial infarction (AMI) and polycythemia. Biochemical studies of the patient's hemoglobin (Hb) and the sequencing of his globin genes revealed that the polycythemia was secondary to a high oxygen affinity Hb variant, Hb Fuchu-II. Hb variants with high oxygen affinity can be an additional thrombotic risk factor in older patients and/or those with other risk factors. The patient was diagnosed with hemoglobinopathy after the development of AMI and exemplifies the importance of recognizing such conditions and of taking appropriate prophylactic interventions.