RESUMO
Newly synthesized proteins engage molecular chaperones that assist folding. Their progress is monitored by quality control systems that target folding errors for degradation. Paradoxically, chaperones that promote folding also direct unfolded polypeptides for degradation. Hence, a mechanism was previously hypothesized that prevents the degradation of actively folding polypeptides. In this study, we show that a conserved endoplasmic reticulum (ER) membrane protein complex, consisting of Slp1 and Emp65 proteins, performs this function in the ER lumen. The complex binds unfolded proteins and protects them from degradation during folding. In its absence, approximately 20%-30% of newly synthesized proteins that could otherwise fold are degraded. Although the Slp1-Emp65 complex hosts a broad range of clients, it is specific for soluble proteins. Taken together, these studies demonstrate the vulnerability of newly translated, actively folding polypeptides and the discovery of a new proteostasis functional class we term "guardian" that protects them from degradation.
Assuntos
Retículo Endoplasmático/metabolismo , Dobramento de Proteína , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Animais , Degradação Associada com o Retículo Endoplasmático , Glicosilação , Camundongos , Chaperonas Moleculares/metabolismo , Proteólise , Saccharomyces cerevisiae/citologia , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Transporte Vesicular/químicaRESUMO
Skin epidermis constitutes the outer permeability barrier that protects the body from dehydration, heat loss, and myriad external assaults. Mechanisms that maintain barrier integrity in constantly challenged adult skin and how epidermal dysregulation shapes the local immune microenvironment and whole-body metabolism remain poorly understood. Here, we demonstrate that inducible and simultaneous ablation of transcription factor-encoding Ovol1 and Ovol2 in adult epidermis results in barrier dysregulation through impacting epithelial-mesenchymal plasticity and inflammatory gene expression. We find that aberrant skin immune activation then ensues, featuring Langerhans cell mobilization and T cell responses, and leading to elevated levels of secreted inflammatory factors in circulation. Finally, we identify failure to gain body weight and accumulate body fat as long-term consequences of epidermal-specific Ovol1/2 loss and show that these global metabolic changes along with the skin barrier/immune defects are partially rescued by immunosuppressant dexamethasone. Collectively, our study reveals key regulators of adult barrier maintenance and suggests a causal connection between epidermal dysregulation and whole-body metabolism that is in part mediated through aberrant immune activation.
Assuntos
Proteínas de Ligação a DNA , Epiderme , Proteínas de Ligação a DNA/genética , Epiderme/metabolismo , Pele/metabolismo , Fatores de Transcrição/metabolismo , Células Epidérmicas/metabolismoRESUMO
Cancer cells adapt to varying stress conditions to survive through plasticity. Stem cells exhibit a high degree of plasticity, allowing them to generate more stem cells or differentiate them into specialized cell types to contribute to tissue development, growth, and repair. Cancer cells can also exhibit plasticity and acquire properties that enhance their survival. TGF-ß is an unrivaled growth factor exploited by cancer cells to gain plasticity. TGF-ß-mediated signaling enables carcinoma cells to alter their epithelial and mesenchymal properties through epithelial-mesenchymal plasticity (EMP). However, TGF-ß is a multifunctional cytokine; thus, the signaling by TGF-ß can be detrimental or beneficial to cancer cells depending on the cellular context. Those cells that overcome the anti-tumor effect of TGF-ß can induce epithelial-mesenchymal transition (EMT) to gain EMP benefits. EMP allows cancer cells to alter their cell properties and the tumor immune microenvironment (TIME), facilitating their survival. Due to the significant roles of TGF-ß and EMP in carcinoma progression, it is essential to understand how TGF-ß enables EMP and how cancer cells exploit this plasticity. This understanding will guide the development of effective TGF-ß-targeting therapies that eliminate cancer cell plasticity.
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Carcinoma , Fator de Crescimento Transformador beta , Humanos , Fator de Crescimento Transformador beta/metabolismo , Transição Epitelial-Mesenquimal/genética , Citocinas , Transdução de Sinais , Microambiente TumoralRESUMO
This study examines the prognostic role and immunological relevance of EMP1 (epithelial membrane protein-1) in a pan-cancer analysis, with a focus on ovarian cancer. Utilizing data from TCGA, CCLE, and GTEx databases, we assessed EMP1 mRNA expression and its correlation with tumor progression, prognosis, and immune microenvironment across various cancers. Our results indicate that EMP1 expression is significantly associated with poor prognosis in multiple cancer types, including ovarian, bladder, testicular, pancreatic, breast, brain, and uveal melanoma. Immune-related analyses reveal a positive correlation between EMP1 and immune cell infiltration, particularly neutrophils, macrophages, and dendritic cells, as well as high expression of immune checkpoint such as CD274, HAVCR2, IL10, PDCD1LG2, and TGFB1 in most tumors. In vivo experiments confirm that EMP1 promotes ovarian cancer cell proliferation, metastasis, and invasion. In conclusion, EMP1 emerges as a potential prognostic biomarker and therapeutic target in various cancers, particularly ovarian cancer, due to its influence on tumor progression and immune cell dynamics. Further research is warranted to elucidate the precise mechanisms of EMP1 in cancer biology and to translate these findings into clinical applications.
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Progressão da Doença , Neoplasias Ovarianas , Animais , Feminino , Humanos , Camundongos , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glicoproteínas de Membrana/genética , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/patologia , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/imunologia , Neoplasias Ovarianas/patologia , Prognóstico , Microambiente Tumoral/imunologia , Microambiente Tumoral/genéticaRESUMO
BACKGROUND: Hemangioblasts are mesoderm-derived multipotent stem cells for differentiation of all hematopoietic and endothelial cells in the circulation system. However, the underlying molecular mechanism is poorly understood. METHODS: CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (type II CRISPR RNA-guided endonuclease) editing was used to develop aggf1-/- and emp2-/- knockout zebra fish. Whole-mount in situ hybridization and transgenic Tg(gata1-EGFP [enhanced green fluorescent protein]), Tg(mpx-EGFP), Tg(rag2-DsRed [discosoma sp. red fluorescent protein]), Tg(cd41-EGFP), Tg(kdrl-EGFP), and Tg(aggf1-/-;kdrl-EGFP) zebra fish were used to examine specification of hemangioblasts and hematopoietic stem and progenitor cells (HSPCs), hematopoiesis, and vascular development. Quantitative real-time polymerase chain reaction and Western blot analyses were used for expression analysis of genes and proteins. RESULTS: Knockout of aggf1 impaired specification of hemangioblasts and HSPCs, hematopoiesis, and vascular development in zebra fish. Expression of npas4l/cloche-the presumed earliest marker for hemangioblast specification-was significantly reduced in aggf1-/- embryos and increased by overexpression of aggf1 in embryos. Overexpression of npas4l rescued the impaired specification of hemangioblasts and HSPCs and development of hematopoiesis and intersegmental vessels in aggf1-/- embryos, placing aggf1 upstream of npas4l in hemangioblast specification. To identify the underlying molecular mechanism, we identified emp2 as a key aggf1 downstream gene. Similar to aggf1, emp2 knockout impaired the specification of hemangioblasts and HSPCs, hematopoiesis, and angiogenesis by increasing the phosphorylation of ERK1/2 (extracellular signal-regulated protein kinase 1/2). Mechanistic studies showed that aggf1 knockdown and knockout significantly decreased the phosphorylated levels of mTOR (mammalian target of rapamycin) and p70 S6K (ribosomal protein S6 kinase), resulting in reduced protein synthesis of Emp2 (epithelial membrane protein 2), whereas mTOR activator MHY1485 (4,6-dimorpholino-N-(4-nitrophenyl)-1,3,5-triazin-2-amine) rescued the impaired specification of hemangioblasts and HSPCs and development of hematopoiesis and intersegmental vessels and reduced Emp2 expression induced by aggf1 knockdown. CONCLUSIONS: These results indicate that aggf1 acts at the top of npas4l and becomes the earliest marker during specification of hemangioblasts. Our data identify a novel signaling axis of Aggf1 (angiogenic factor with G-patch and FHA domain 1)-mTOR-S6K-ERK1/2 for specification of hemangioblasts and HSPCs, primitive and definitive hematopoiesis, and vascular development. Our findings provide important insights into specification of hemangioblasts and HSPCs essential for the development of the circulation system.
Assuntos
Hemangioblastos , Animais , Animais Geneticamente Modificados , Diferenciação Celular , Hemangioblastos/metabolismo , Hematopoese/genética , Mamíferos , Serina-Treonina Quinases TOR/metabolismo , Peixe-Zebra/genética , Peixe-Zebra/metabolismoRESUMO
BACKGROUND: p24/transmembrane Emp24 domain (TMED) proteins are a set of evolutionarily conserved, single pass transmembrane proteins that have been shown to facilitate protein secretion and selection of cargo proteins to transport vesicles in the cellular secretion pathway. However, their functions in animal development are incompletely understood. RESULTS: The C. elegans genome encodes eight identified TMED genes, with at least one member from each defined subfamily (α, ß, γ, δ). TMED gene mutants exhibit a shared set of defects in embryonic viability, animal movement, and vulval morphology. Two γ subfamily genes, tmed-1 and tmed-3, exhibit the ability to compensate for each other, as defects in movement and vulva morphology are only apparent in double mutants. TMED mutants also exhibit a delay in breakdown of basement membrane during vulva development. CONCLUSIONS: The results establish a genetic and experimental framework for the study of TMED gene function in C. elegans, and argue that a functional protein from each subfamily is important for a shared set of developmental processes. A specific function for TMED genes is to facilitate breakdown of the basement membrane between the somatic gonad and vulval epithelial cells, suggesting a role for TMED proteins in tissue reorganization during animal development.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Animais , Feminino , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Membrana/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Fenótipo , Biomarcadores , Vulva/metabolismoRESUMO
In a variety of European countries SEM/EDXA based methods are widely used for the measurements and judgements relating thereof regarding asbestos analysis. Most of these methods are used also for other fibrous particles, commonly indicated as Elongate Mineral Particles (EMPs). The span of guidelines reflects the broad use of SEM/EDXA as an analytical method. Guidelines regarding air measurements both for ambient and indoor air are well established. These methods are widely used as is shown in a proficiency testing scheme, organized by the British Health and Safety Executive (HSL) with participants from countries all over Europe and some countries from Asia and Africa. For workplaces a similar guideline with a reduced sensitivity is available, allowing measurements in higher dust concentrations. Features of the methods like analytical sensitivity, detection limits and measurement uncertainty are discussed. For material analysis we apply different analytical methods, using SEM/EDXA as a final step. They are different both in sample preparation and sensitivity. Most of the methods are qualitative or "semi-quantitative" and thought for the analysis of commercial asbestos containing products mainly. If quantitative analysis based on EDXA is used for identification other EMPs can be identified as well. An important tool is the morphological impression of the fibers or structures in the SEM in addition. Changes in regulations which may be expected, will modify some of the methods. Especially lowered Threshold Limit Values (TLV's) in occupational air measurements are difficult to achieve.
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Amianto , Minerais , Humanos , Microscopia Eletrônica de Varredura , Minerais/análise , Poeira/análise , Níveis Máximos PermitidosRESUMO
The presentations in this session of the Monticello II conference were aimed at summarizing what is known about asbestiform and non-asbestiform elongate mineral particles (EMPs) and mesothelioma risks based on evidence from experimental and epidemiology studies. Dr. Case discussed case reports of mesothelioma over the last several decades. Dr. Taioli indicated that the epidemiology evidence concerning non-asbestiform EMPs is weak or lacking, and that progress would be limited unless mesothelioma registries are established. One exception discussed is that of taconite miners, who are exposed to grunerite. Drs. Mandel and Odo noted that studies of taconite miners in Minnesota have revealed an excess rate of mesothelioma, but the role of non-asbestiform EMPs in this excess incidence of mesothelioma is unclear. Dr. Becich discussed the National Mesothelioma Virtual Bank (NMVB), a virtual mesothelioma patient registry that includes mesothelioma patients' lifetime work histories, exposure histories, biospecimens, proteogenomic information, and imaging data that can be used in epidemiology research on mesothelioma. Dr. Bernstein indicated that there is a strong consensus that long, highly durable respirable asbestiform EMPs have the potential to cause mesothelioma, but there is continued debate concerning the biodurability required, and the dimensions (both length and diameter), the shape, and the dose associated with mesothelioma risk. Finally, Dr. Nel discussed how experimental studies of High Aspect Ratio Engineered Nanomaterials have clarified dimensional and durability features that impact disease risk, the impact of inflammation and oxidative stress on the epigenetic regulation of tumor suppressor genes, and the generation of immune suppressive effects in the mesothelioma tumor microenvironment. The session ended with a discussion of future research needs.
Assuntos
Poluentes Ocupacionais do Ar , Amianto , Neoplasias Pulmonares , Mesotelioma , Exposição Ocupacional , Humanos , Epigênese Genética , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Minerais/análise , Mesotelioma/induzido quimicamente , Mesotelioma/epidemiologia , Amianto/toxicidade , Microambiente TumoralRESUMO
BACKGROUND: Cystic echinococcosis (CE) is one of the most widespread and important global helminth zoonoses. Treatment relies mainly on surgery and, or percutaneous interventions. However, spillage of live protoscoleces (PSCs) leading to recurrence is a problem during surgery. So, the application of protoscolicidal agents before surgery is required. This study aimed to investigate the activity and safety of hydroalcoholic extracts of E. microtheca against PSCs of Echinococcus granulosus sensu stricto (s.s.) both in vitro and also ex vivo, which is a simulation to Puncture, Aspiration, Injection, and Re-aspiration (PAIR) method. METHODS: Considering the effects of heat on the protoscolicidal effecacy of Eucalyptus leaves, hydroalcoholic extraction was performed by both soxhlet extraction at 80 °C and percolation at room temperature. The protoscolicidal action of hydroalcoholic extracts was assessed by in vitro and ex vivo assessments. Infected sheep livers were collected from the slaughterhouse. Then, the genotype of hydatid cysts (HCs) was confirmed by sequencing and, isolates were limited to E. granulosus s.s. In the next step, ultrastructural changes of Eucalyptus-exposed PSCs were studied by scanning electron microscopy (SEM). Finally, a cytotoxicity test was conducted by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to evaluate the safety of E. microtheca. RESULTS: The prepared extracts by soxhlet extraction and percolation were, successfully exerted strong protoscolicidal effects in both in vitro and ex vivo tests. The results of in vitro assessment indicated that hydroalcoholic extract of E. microtheca prepared by percolation at room temperature (EMP) and hydroalcoholic extract of E. microtheca prepared by soxhlet extraction at 80 °C (EMS) killed all PSCs (100%) at concentrations of 10 and 12.5 mg/mL, respectively. Also, EMP showed 99% protoscolicidal action after 20 min in an ex vivo setting compared to EMS. SEM micrographs confirmed potent protoscolicidal and destructive effects of E. microtheca against PSCs. The cytotoxicity of EMP was tested on the HeLa cell line using MTT assay. The value of 50% cytotoxic concentration (CC50) was calculated at 46.5 µg/mL after 24h. CONCLUSION: Both hydroalcoholic extracts showed potent protoscolicidal activity and, especially EMP produced remarkable protoscolicidal effects compared to the control group.
Assuntos
Equinococose , Echinococcus granulosus , Eucalyptus , Humanos , Animais , Ovinos , Microscopia Eletrônica de Varredura , Células HeLa , Equinococose/tratamento farmacológico , Equinococose/veterinária , Extratos Vegetais/farmacologiaRESUMO
Postharvest abnormal chilling injury (CI) behavior in papaya (Carica papaya L.) fruit is a rare phenomenon that may be associated with respiratory metabolism. This study thus aimed to investigate the impacts of storage temperatures (1 and 6 °C) on the respiratory metabolism of postharvest papaya and its impact on CI development. Results demonstrated that 1 °C storage reduced the activities of hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), citrate synthase (CS), and α-ketoglutarate dehydrogenase (α-KGDH) and regulated the expression of corresponding enzymes in the Embden-Meyerhof-Parnas (EMP) pathway and tricarboxylic acid (TCA) cycle compared with 6 °C storage, resulting in a lower respiration rate of the EMP-TCA pathway and mitigating the development of CI. Meanwhile, lower contents of nicotinamide adenine dinucleotide (hydrogen) (NAD(H)) were observed in papaya fruit stored at 1 °C. Notably, papaya fruit stored at 1 °C maintained higher activity and transcriptional levels of SDH and IDH during the whole storage period. These findings suggest that 1 °C storage reduced the respiration rate of the EMP-TCA pathway by reducing the expression level and activity of related enzymes, which is conducive to the reduction of respiration substrate consumption and finally alleviating the occurrence of CI.
RESUMO
The effect of nanosecond electromagnetic pulses on human health, and especially on forming free radicals in human cells, is the subject of continuous research and ongoing discussion. This work presents a preliminary study on the effect of a single high-energy electromagnetic pulse on morphology, viability, and free radical generation in human mesenchymal stem cells (hMSC). The cells were exposed to a single electromagnetic pulse with an electric field magnitude of ~1 MV/m and a pulse duration of ~120 ns generated from a 600 kV Marx generator. The cell viability and morphology at 2 h and 24 h after exposure were examined using confocal fluorescent microscopy and scanning electron microscopy (SEM), respectively. The number of free radicals was investigated with electron paramagnetic resonance (EPR). The microscopic observations and EPR measurements showed that the exposure to the high-energy electromagnetic pulse influenced neither the number of free radicals generated nor the morphology of hMSC in vitro compared to control samples.
Assuntos
Fenômenos Eletromagnéticos , Células-Tronco Mesenquimais , Humanos , Radicais Livres , Fatores ImunológicosRESUMO
Despite recent advances in the treatment of non-small cell lung cancer (NSCLC), acquired drug resistance to targeted therapy remains a major obstacle. Epithelial-mesenchymal transition (EMT) has been identified as a key resistance mechanism in NSCLC. Here, we investigated the mechanistic role of key EMT-regulating small non-coding microRNAs (miRNAs) in sublines of the NSCLC cell line HCC4006 adapted to afatinib, erlotinib, gefitinib, or osimertinib. The most differentially expressed miRNAs derived from extracellular vesicles were associated with EMT, and their predicted target ZEB1 was significantly overexpressed in all resistant cell lines. Transfection of a miR-205-5p mimic partially reversed EMT by inhibiting ZEB1, restoring CDH1 expression, and inhibiting migration in erlotinib-resistant cells. Gene expression of EMT-markers, transcription factors, and miRNAs were correlated during stepwise osimertinib adaptation of HCC4006 cells. Temporally relieving cells of osimertinib reversed transition trends, suggesting that the implementation of treatment pauses could provide prolonged benefits for patients. Our results provide new insights into the contribution of miRNAs to drug-resistant NSCLC harboring EGFR-activating mutations and highlight their role as potential biomarkers and therapeutic targets.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , MicroRNAs , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , MicroRNAs/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Cloridrato de Erlotinib/uso terapêutico , Transição Epitelial-Mesenquimal/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Receptores ErbB/genética , Receptores ErbB/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Mutação , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genéticaRESUMO
The epithelial-mesenchymal transition (EMT) is a cellular reprogramming process that occurs during embryonic development and adult tissue homeostasis. This process involves epithelial cells acquiring a mesenchymal phenotype. Through EMT, cancer cells acquire properties associated with a more aggressive phenotype. EMT and its opposite, mesenchymal-epithelial transition (MET), have been described in more tumors over the past ten years, including colorectal cancer (CRC). When EMT is activated, the expression of the epithelial marker E-cadherin is decreased and the expression of the mesenchymal marker vimentin is raised. As a result, cells temporarily take on a mesenchymal phenotype, becoming motile and promoting the spread of tumor cells. Epithelial-mesenchymal plasticity (EMP) has become a hot issue in CRC because strong inducers of EMT (such as transforming growth factor ß, TGF-ß) can initiate EMT and regulate metastasis, microenvironment, and immune system resistance in CRC. In this review, we take into account the significance of EMT-MET in CRC and the impact of the epithelial cells' plasticity on the prognosis of CRC. The analysis of connection between EMT and colorectal cancer stem cells (CCSCs) will help to further clarify the current meager understandings of EMT. Recent advances affecting important EMT transcription factors and EMT and CCSCs are highlighted. We come to the conclusion that the regulatory network for EMT in CRC is complicated, with a great deal of crosstalk and alternate paths. More thorough research is required to more effectively connect the clinical management of CRC with biomarkers and targeted treatments associated with EMT.
Assuntos
Neoplasias Colorretais , Transição Epitelial-Mesenquimal , Adulto , Humanos , Transição Epitelial-Mesenquimal/genética , Neoplasias Colorretais/patologia , Diferenciação Celular/genética , Caderinas/genética , Fatores de Transcrição , Fator de Crescimento Transformador beta , Linhagem Celular Tumoral , Microambiente TumoralRESUMO
Although epithelial-mesenchymal transition (EMT) is a common feature of fibrotic lung disease, its role in fibrogenesis is controversial. Recently, aberrant basaloid cells were identified in fibrotic lung tissue as a novel epithelial cell type displaying a partial EMT phenotype. The developmental origin of these cells remains unknown. To elucidate the role of EMT in the development of aberrant basaloid cells from the bronchial epithelium, we mapped EMT-induced transcriptional changes at the population and single-cell levels. Human bronchial epithelial cells grown as submerged or air-liquid interface (ALI) cultures with or without EMT induction were analyzed by bulk and single-cell RNA-Sequencing. Comparison of submerged and ALI cultures revealed differential expression of 8,247 protein coding (PC) and 1,621 long noncoding RNA (lncRNA) genes and revealed epithelial cell-type-specific lncRNAs. Similarly, EMT induction in ALI cultures resulted in robust transcriptional reprogramming of 6,020 PC and 907 lncRNA genes. Although there was no evidence for fibroblast/myofibroblast conversion following EMT induction, cells displayed a partial EMT gene signature and an aberrant basaloid-like cell phenotype. The substantial transcriptional differences between submerged and ALI cultures highlight that care must be taken when interpreting data from submerged cultures. This work supports that lung epithelial EMT does not generate fibroblasts/myofibroblasts and confirms ALI cultures provide a physiologically relevant system to study aberrant basaloid-like cells and mechanisms of EMT. We provide a catalog of PC and lncRNA genes and an interactive browser (https://bronc-epi-in-vitro.cells.ucsc.edu/) of single-cell RNA-Seq data for further exploration of potential roles in the lung epithelium in health and lung disease.
Assuntos
Pneumopatias , RNA Longo não Codificante , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal/genética , Epitélio/metabolismo , Humanos , Pneumopatias/metabolismo , RNA Longo não Codificante/genética , Mucosa Respiratória/metabolismoRESUMO
Early embryonic hematopoiesis in mammals is defined by three successive waves of hematopoietic progenitors which exhibit a distinct hematopoietic potential and provide continuous support for the development of the embryo and adult organism. Although the functional importance of each of these waves has been analyzed, their spatio-temporal overlap and the lack of wave-specific markers hinders the accurate separation and assessment of their functional roles during early embryogenesis. We have recently shown that TLR2, in combination with c-kit, represents the earliest signature of emerging precursors of the second hematopoietic wave, erythro-myeloid precursors (EMPs). Since the onset of Tlr2 expression distinguishes EMPs from primitive progenitors which coexist in the yolk sac from E7.5, we generated a novel transgenic "knock in" mouse model, Tlr2Dtr , suitable for inducible targeted depletion of TLR2+ EMPs. In this model, the red fluorescent protein and diphtheria toxin receptor sequences are linked via a P2A sequence and inserted into the Tlr2 locus before its stop codon. We show that a timely controlled deletion of TLR2+ EMPs in Tlr2Dtr embryos results in a marked decrease in both erythroid as well as myeloid lineages and, consequently, in embryonic lethality peaking before E13.5. These findings validate the importance of EMPs in embryonic development.
Assuntos
Embrião de Mamíferos/patologia , Desenvolvimento Embrionário/genética , Hematopoese/genética , Células Progenitoras Mieloides/citologia , Receptor 2 Toll-Like/genética , Animais , Embrião de Mamíferos/embriologia , Eritrócitos/citologia , Hematopoese/fisiologia , Macrófagos/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos TransgênicosRESUMO
RNA C-to-U editing is important to the expression and function of organellar genes in plants. Although several families of proteins have been identified to participate in this process, the underlying mechanism is not fully understood. Here we report the function of EMP80 in the C-to-U editing at the nad7-769 and atp4-118 sites, and the potential recruitment of ZmDYW2 as a trans deaminase in maize (Zea mays) mitochondria. Loss of EMP80 function arrests embryogenesis and endosperm development in maize. EMP80 is a PPR-E+ protein localised to mitochondria. An absence of EMP80 abolishes the C-to-U RNA editing at nad7-769 and atp4-118 sites, resulting in a cysteine-to-arginine (CysâArg) change in Nad7 and Atp4 in the emp80 mutant. The amino acid change consequently reduces the assembly of complexes I and V, leading to an accumulation of the F1 subcomplex of complex V. EMP80 was found to interact with atypical DYW-type PPR protein ZmDYW2, which interacts with ZmNUWA. Co-expression of ZmNUWA enhances the interaction between EMP80 and ZmDYW2, suggesting that EMP80 potentially recruits ZmDYW2 as a trans deaminase through protein-protein interaction, and ZmNUWA may function as an enhancer of this interaction.
Assuntos
Proteínas de Plantas , Zea mays , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/metabolismo , Sementes/genética , Zea mays/metabolismoRESUMO
The MAM blood group system (International Society of Blood Transfusion [ISBT] 041) consists of one high-prevalence antigen to date, first detected in a 31-year-old woman during her third pregnancy. Epithelial membrane protein 3 (EMP3) was recently identified as the gene coding the MAM antigen. Six unique genetic variants have been described in EMP3 in 11 MAM- individuals. EMP3 is an 18-kDa glycoprotein with a large extracellular domain containing at least one N-glycosylation site. The normal function of EMP3 is still unclear, but ex vivo culture of erythropoietic progenitor cells from MAM- individuals shows an increased yield of reticulocytes, suggesting that EMP3 acts as a brake during normal erythropoiesis. EMP3 is abundant on different cell types, including many epithelial tissues and blood cells. Interestingly, EMP3 expression has been suggested as a prognostic marker for a number of cancer types, both for good and poor prognoses. EMP3 may act as a tumor suppressor or an oncogene in different cancer contexts. The protein appears to interact with other cell surface receptors and affects the downstream signaling and function of these proteins. MAM- red blood cells express low levels of CD44 and, consequently, the antigens of the Indian blood group system are only weakly expressed. Clinically, the MAM blood group antigen is important with regard to blood transfusion and pregnancy. Anti-MAM can cause severe hemolytic disease of the fetus and newborn in some pregnancies but have little to no effect in other pregnancies. Cases are typically not detected until problems occur during pregnancy, making the availability of compatible blood a challenge.
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Antígenos de Grupos Sanguíneos , Glicoproteínas de Membrana , Neoplasias , Humanos , Antígenos de Grupos Sanguíneos/genética , Eritropoese , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Neoplasias/genéticaRESUMO
This paper compares model development strategies based on different performance metrics. The study was conducted in the area of credit risk modeling with the usage of diverse metrics, including general-purpose Area Under the ROC curve (AUC), problem-dedicated Expected Maximum Profit (EMP) and the novel case-tailored Calculated Profit (CP). The metrics were used to optimize competitive credit risk scoring models based on two predictive algorithms that are widely used in the financial industry: Logistic Regression and extreme gradient boosting machine (XGBoost). A dataset provided by the American Fannie Mae agency was utilized to conduct the study. In addition to the baseline study, the paper also includes a stability analysis. In each case examined the proposed CP metric that allowed us to achieve the most profitable loan portfolio.
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Sodium-glucose co-transporter 2 (SGLT 2) inhibitors are a relatively new antidiabetic drug with antioxidant and anti-inflammatory properties. Therefore, this study aimed to investigate whether SGLT 2 inhibitors have a neuroprotective effect in PD. Twenty-four Wistar rats were randomized into four groups. The first one (control group) received dimethyl sulfoxide (DMSO) as a vehicle (0.2 mL/48 hr, S.C). The second group (positive control) received rotenone (ROT) (2.5 mg/kg/48 hr, S.C) for 20 successive days, whereas the third and fourth groups received empagliflozin (EMP) (1 and 2 mg/kg/day, orally), respectively. The two groups received rotenone (2.5 mg/kg/48 hr S.C) concomitantly with EMP for another 20 days on the fifth day. By the end of the experimental period, behavioral examinations were done. Subsequently, rats were sacrificed, blood samples and brain tissues were collected for analysis. ROT significantly elevated oxidative stress and proinflammatory markers as well as α-synuclein. However, dopamine (DP), antioxidants, tyrosine hydroxylase (TH), and Parkin were significantly decreased. Groups of (EMP + ROT) significantly maintained oxidative stress and inflammatory markers elevation, maintained α-synuclein and Parkin levels, and elevated TH activity and dopamine level. In both low and high doses, EMP produced a neuroprotective effect against the PD rat model, with the high dose inducing a more significant effect.
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Intron splicing is an essential event in post-transcriptional RNA processing in plant mitochondria, which requires the participation of diverse nuclear-encoded splicing factors. However, it is presently unclear how these proteins cooperatively take part in the splicing of specific introns. In this study, we characterized a nuclear-encoded mitochondrial P-type pentatricopeptide repeat (PPR) protein named EMP603. This protein is essential for splicing of intron 2 in the Nad1 gene and interacts with the mitochondria-localized DEAD-box RNA helicase PMH2-5140, the RAD52-like proteins ODB1-0814 and ODB1-5061, and the CRM domain-containing protein Zm-mCSF1. Further study revealed that the N-terminal region of EMP603 interacts with the DEAD-box of PMH2-5140, the CRM domain of Zm-mCSF1, and OBD1-5061, but not with OBD1-0814, whereas the PPR domain of EMP603 can interact with ODB1-0814, ODB1-5061, and PMH2-5140, but not with Zm-mCSF1. Defects in EMP603 severely disrupt the assembly and activity of mitochondrial complex I, leading to impaired mitochondrial function, and delayed seed development. The interactions revealed between EMP603 and PMH2-5140, ODB1-0814, ODB1-5061, and Zm-mCSF1 indicate a possible involvement of a dynamic 'spliceosome-like' complex in intron splicing, and may accelerate the elucidation of the intron splicing mechanism in plant mitochondria.