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1.
Eur Heart J ; 44(2): 113-125, 2023 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-36337036

RESUMO

BACKGROUND: It remains unknown whether the presence of coronary microcirculatory dysfunction (CMD) correlates with its equivalent condition in the brain, cerebral small vessel disease (CSVD). The cerebral-coronary connection (C3), a prospective blinded study, investigated the prevalence of CMD in patients with coronary artery disease (CAD) and its association with CSVD and cognitive function. METHODS AND RESULTS: Patients with documented CAD fulfilling inclusion criteria underwent physiological assessment of epicardial vessels and the microcirculation using intracoronary pressure and Doppler. Coronary microcirculation-related indices included coronary flow reserve (CFR) and hyperaemic microvascular resistance. Brain magnetic resonance imaging, transcranial Doppler (TCD), and neurocognitive examination were performed. Overall, 67 patients were included in the study (mean age 66 years, 73% female). Patients with abnormal CFR (<2.0) (55.2%) showed higher burden of white-matter hyperintensities: 43.2 vs. 20.0% (P = 0.044). After statistical adjustment, low CFR was associated with lower grey matter volume (P = 0.024) and with parameters of white-matter microstructural damage in diffusion-tensor imaging (lower fractional anisotropy and higher mean diffusivity, P = 0.029 and P = 0.032, respectively). Low CFR was associated with higher resistive (P = 0.027) and pulsatility (P = 0.043) values on TCD, and worse neurocognitive test scores (lower mini mental state examination, P = 0.025, and slower Trail Making Test A, P = 0.034). CONCLUSIONS: Coronary microcirculatory dysfunction is frequent in patients with CAD and correlates with CSVD, abnormal cerebral flow haemodynamics, and significant cognitive impairment. These findings support the hypothesis that microvascular dysfunction in the heart and the brain are part of a single pathological process affecting microcirculation in patients with CAD. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov NCT04131075.


Assuntos
Doença da Artéria Coronariana , Reserva Fracionada de Fluxo Miocárdico , Cardiopatias , Isquemia Miocárdica , Idoso , Feminino , Humanos , Masculino , Cognição , Angiografia Coronária , Doença da Artéria Coronariana/diagnóstico por imagem , Vasos Coronários , Microcirculação/fisiologia , Estudos Prospectivos , Resistência Vascular
2.
J Cell Sci ; 134(16)2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34346498

RESUMO

Chromosome segregation in female meiosis in many metazoans is mediated by acentrosomal spindles, the existence of which implies that microtubule spindles self-assemble without the participation of the centrosomes. Although it is thought that acentrosomal meiosis is not conserved in fungi, we recently reported the formation of self-assembled microtubule arrays, which were able to segregate chromosomes, in fission yeast mutants, in which the contribution of the spindle pole body (SPB; the centrosome equivalent in yeast) was specifically blocked during meiosis. Here, we demonstrate that this unexpected microtubule formation represents a bona fide type of acentrosomal spindle. Moreover, a comparative analysis of these self-assembled spindles and the canonical SPB-dependent spindle reveals similarities and differences; for example, both spindles have a similar polarity, but the location of the γ-tubulin complex differs. We also show that the robustness of self-assembled spindles can be reinforced by eliminating kinesin-8 family members, whereas kinesin-8 mutants have an adverse impact on SPB-dependent spindles. Hence, we consider that reinforced self-assembled spindles in yeast will help to clarify the molecular mechanisms behind acentrosomal meiosis, a crucial step towards better understanding gametogenesis.


Assuntos
Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Feminino , Humanos , Cinesinas/genética , Meiose , Microtúbulos , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Fuso Acromático/genética , Corpos Polares do Fuso
3.
Mult Scler ; 29(11-12): 1393-1405, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37772510

RESUMO

BACKGROUND: Radiologically isolated syndrome (RIS) patients might have psychiatric and cognitive deficits, which suggests an involvement of major resting-state functional networks. Notwithstanding, very little is known about the neural networks involved in RIS. OBJECTIVE: To examine functional connectivity differences between RIS and healthy controls using resting-state functional magnetic resonance imaging (fMRI). METHODS: Resting-state fMRI data in 25 RIS patients and 28 healthy controls were analyzed using an independent component analysis; in addition, seed-based correlation analysis was used to obtain more information about specific differences in the functional connectivity of resting-state networks. Participants also underwent neuropsychological testing. RESULTS: RIS patients did not differ from the healthy controls regarding age, sex, and years of education. However, in memory (verbal and visuospatial) and executive functions, RIS patients' cognitive performance was significantly worse than the healthy controls. In addition, fluid intelligence was also affected. Twelve out of 25 (48%) RIS patients failed at least one cognitive test, and six (24.0%) had cognitive impairment. Compared to healthy controls, RIS patients showed higher functional connectivity between the default mode network and the right middle and superior frontal gyri and between the central executive network and the right thalamus (pFDR < 0.05; corrected). In addition, the seed-based correlation analysis revealed that RIS patients presented higher functional connectivity between the posterior cingulate cortex, an important hub in neural networks, and the right precuneus. CONCLUSION: RIS patients had abnormal brain connectivity in major resting-state neural networks and worse performance in neurocognitive tests. This entity should be considered not an "incidental finding" but an exclusively non-motor (neurocognitive) variant of multiple sclerosis.


Assuntos
Mapeamento Encefálico , Imageamento por Ressonância Magnética , Humanos , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética/métodos , Encéfalo/patologia , Giro do Cíngulo , Lobo Parietal , Vias Neurais/diagnóstico por imagem
4.
J Int Neuropsychol Soc ; 28(9): 947-962, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34569460

RESUMO

OBJECTIVE: Cognitive processes underlying verbal and design fluency, and their neural correlates in patients with Alzheimer's disease (AD) and behavioural variant Frontotemporal Dementia (bvFTD) remain unclear. We hypothesised that verbal and design fluency may be associated with distinct neuropsychological processes in AD and FTD, showing different patterns of impairment and neural basis. METHODS: We enrolled 142 participants including patients with AD (n = 80, mean age = 74.71), bvFTD (n = 34, mean age = 68.18), and healthy controls (HCs) (n = 28, mean age = 71.14), that underwent cognitive assessment and 18F-fluorodeoxyglucose positron emission tomography imaging. RESULTS: Semantic and phonemic fluency showed the largest effect sizes between groups, showing lower scores in bvFTD than AD and HCs, and lower scores in AD than HC. Both AD and bvFTD showed a lower number of unique designs in design fluency in comparison to HC. Semantic fluency was correlated with left frontotemporal lobe in AD, and with left frontal, caudate, and thalamus in bvFTD. Percentage of unique designs in design fluency was associated with the metabolism of the bilateral fronto-temporo-parietal cortex in AD, and the bilateral frontal cortex with right predominance in bvFTD. Repetitions in AD were correlated with bilateral frontal, temporal, and parietal lobes, and with left prefrontal cortex in bvFTD. CONCLUSIONS: Our findings demonstrate differential underlying cognitive processes in verbal and design fluency in AD and bvFTD. While memory and executive functioning associated with fronto-temporo-parietal regions were key in AD, attention and executive functions correlated with the frontal cortex and played a more significant role in bvFTD during fluency tasks.


Assuntos
Doença de Alzheimer , Demência Frontotemporal , Idoso , Doença de Alzheimer/complicações , Função Executiva , Fluordesoxiglucose F18 , Demência Frontotemporal/complicações , Humanos , Testes Neuropsicológicos
5.
Int J Mol Sci ; 23(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36498916

RESUMO

26S proteasome non-ATPase subunits 1 (PSMD1) and 3 (PSMD3) were recently identified as prognostic biomarkers and potential therapeutic targets in chronic myeloid leukemia (CML) and multiple solid tumors. In the present study, we analyzed the expression of 19S proteasome subunits in acute myeloid leukemia (AML) patients with mutations in the FMS-like tyrosine kinase 3 (FLT3) gene and assessed their impact on overall survival (OS). High levels of PSMD3 but not PSMD1 expression correlated with a worse OS in FLT3-mutated AML. Consistent with an oncogenic role for PSMD3 in AML, shRNA-mediated PSMD3 knockdown impaired colony formation of FLT3+ AML cell lines, which correlated with increased OS in xenograft models. While PSMD3 regulated nuclear factor-kappa B (NF-κB) transcriptional activity in CML, we did not observe similar effects in FLT3+ AML cells. Rather, proteomics analyses suggested a role for PSMD3 in neutrophil degranulation and energy metabolism. Finally, we identified additional PSMD subunits that are upregulated in AML patients with mutated versus wild-type FLT3, which correlated with worse outcomes. These findings suggest that different components of the 19S regulatory complex of the 26S proteasome can have indications for OS and may serve as prognostic biomarkers in AML and other types of cancers.


Assuntos
Leucemia Mieloide Aguda , Tirosina Quinase 3 Semelhante a fms , Humanos , Tirosina Quinase 3 Semelhante a fms/genética , Complexo de Endopeptidases do Proteassoma/genética , Prognóstico , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Mutação , Oncogenes
6.
Cancer ; 127(7): 1068-1079, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33616915

RESUMO

BACKGROUND: The Texas/Chihuahua (US/Mexico) border is a medically underserved region with many reported barriers for health care access. Although Hispanic ethnicity is associated with health disparities for many different diseases, the population-based estimates of incidence and survival for patients with blood cancer along the border are unknown. The authors hypothesized that Hispanic ethnicity and border proximity is associated with poor blood cancer outcomes. METHODS: Data from the Texas Cancer Registry (1995-2016) were used to investigate the primary exposures of patient ethnicity (Hispanic vs non-Hispanic) and geographic location (border vs non-border). Other confounders and covariates included sex, age, year of diagnosis, rurality, insurance status, poverty indicators, and comorbidities. The Mantel-Haenszel method and Cox regression analyses were used to determine adjusted effects of ethnicity and border proximity on the relative risk (RR) and survival of patients with different blood cancer types. RESULTS: Hispanic patients were diagnosed at a younger age than non-Hispanic patients and presented with increased comorbidities. Whereas non-Hispanics had a higher incidence of developing blood cancer compared with Hispanics overall, Hispanics demonstrated a higher incidence of acute lymphoblastic leukemia (RR, 1.92; 95% CI, 1.79-2.08; P < .001) with worse outcomes. Hispanics from the Texas/Chihuahua border demonstrated a higher incidence of chronic myeloid leukemia (RR, 1.28; 95% CI, 1.07-1.51; P = .02) and acute myeloid leukemia (RR, 1.17; 95% CI, 1.04-1.33; P = .0009) compared with Hispanics living elsewhere in Texas. CONCLUSIONS: Hispanic ethnicity and border proximity were associated with a poor presentation and an adverse prognosis despite the younger age of diagnosis. Future studies should explore differences in disease biology and treatment strategies that could drive these regional disparities.


Assuntos
Doenças Hematológicas/etnologia , Hispânico ou Latino , Área Carente de Assistência Médica , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Acessibilidade aos Serviços de Saúde , Doenças Hematológicas/epidemiologia , Doenças Hematológicas/mortalidade , Humanos , Incidência , Cobertura do Seguro , Leucemia Mielogênica Crônica BCR-ABL Positiva/epidemiologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/etnologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/etnologia , Leucemia Mieloide Aguda/mortalidade , Leucemia Promielocítica Aguda/epidemiologia , Leucemia Promielocítica Aguda/etnologia , Leucemia Promielocítica Aguda/mortalidade , Masculino , México/etnologia , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/epidemiologia , Síndromes Mielodisplásicas/etnologia , Síndromes Mielodisplásicas/mortalidade , Transtornos Mieloproliferativos/epidemiologia , Transtornos Mieloproliferativos/etnologia , Transtornos Mieloproliferativos/mortalidade , Pobreza , Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/etnologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Sistema de Registros , Análise de Regressão , População Rural , Fatores Sexuais , Texas , Adulto Jovem
7.
PLoS Pathog ; 15(11): e1007687, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31730668

RESUMO

Fungal pathogenesis depends on accurate secretion and location of virulence factors which drive host colonization. Protein glycosylation is a common posttranslational modification of cell wall components and other secreted factors, typically required for correct protein localization, secretion and function. Thus, the absence of glycosylation is associated with animal and plant pathogen avirulence. While the relevance of protein glycosylation for pathogenesis has been well established, the main glycoproteins responsible for the loss of virulence observed in glycosylation-defective fungi have not been identified. Here, we devise a proteomics approach to identify such proteins and use it to demonstrate a role for the highly conserved protein disulfide isomerase Pdi1 in virulence. We show that efficient Pdi1 N-glycosylation, which promotes folding into the correct protein conformation, is required for full pathogenic development of the corn smut fungus Ustilago maydis. Remarkably, the observed virulence defects are reminiscent of those seen in glycosylation-defective cells suggesting that the N-glycosylation of Pdi1 is necessary for the full secretion of virulence factors. All these observations, together with the fact that Pdi1 protein and RNA expression levels rise upon virulence program induction, suggest that Pdi1 glycosylation is important for normal pathogenic development in U. maydis. Our results provide new insights into the role of glycosylation in fungal pathogenesis.


Assuntos
Glicoproteínas/metabolismo , Doenças das Plantas/microbiologia , Isomerases de Dissulfetos de Proteínas/metabolismo , Ustilago/patogenicidade , Fatores de Virulência/metabolismo , Zea mays/microbiologia , Glicoproteínas/genética , Glicosilação , Isomerases de Dissulfetos de Proteínas/genética , Proteoma/análise , Ustilago/enzimologia , Virulência , Fatores de Virulência/genética
8.
Int J Geriatr Psychiatry ; 37(2)2021 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-34894410

RESUMO

BACKGROUND: Neuropsychological assessment is considered a valid tool in the diagnosis of neurodegenerative disorders. However, there is an important overlap in cognitive profiles between Alzheimer's disease (AD) and behavioural variant frontotemporal dementia (bvFTD), and the usefulness in diagnosis is uncertain. We aimed to develop machine learning-based models for the diagnosis using cognitive tests. METHODS: Three hundred and twenty-nine participants (170 AD, 72 bvFTD, 87 healthy control [HC]) were enrolled. Evolutionary algorithms, inspired by the process of natural selection, were applied for both mono-objective and multi-objective classification and feature selection. Classical algorithms (NativeBayes, Support Vector Machines, among others) were also used, and a meta-model strategy. RESULTS: Accuracies for the diagnosis of AD, bvFTD and the differential diagnosis between them were higher than 84%. Algorithms were able to significantly reduce the number of tests and scores needed. Free and Cued Selective Reminding Test, verbal fluency and Addenbrooke's Cognitive Examination were amongst the most meaningful tests. CONCLUSIONS: Our study found high levels of accuracy for diagnosis using exclusively neuropsychological tests, which supports the usefulness of cognitive assessment in diagnosis. Machine learning may have a role in improving the interpretation and test selection.

9.
Chromosoma ; 128(3): 267-277, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31152193

RESUMO

Centrosomes represent the major microtubule organizing center (MTOC) in eukaryotic cells and are responsible for nucleation of the spindle, the vehicle of chromosome segregation. In human female meiosis, however, spindle assembly occurs in the absence of centrosomes or other MTOCs and microtubules are nucleated around chromosomes. In yeast, spindle formation in mitosis and meiosis depends on the activity of spindle pole bodies (SPBs), the functional equivalents of centrosomes; thus, SPBs and centrosomes use similar machineries to assemble spindles. Here, we develop a system to explore the molecular mechanisms supporting acentrosomal spindle formation using fission yeast meiosis as a model scenario. We achieve this situation by removing access of the SPBs to the nucleus after their duplication. Under these conditions, we observe self-assembly-based spindle formation in the nuclear environment, conferring an ability to segregate chromosomes independently of the SPBs. Our results open the possibility to utilize the experimental advantages of fission yeast for insights into the molecular basis of acentrosomal spindle formation in meiosis.


Assuntos
Meiose , Membrana Nuclear/metabolismo , Schizosaccharomyces/fisiologia , Fuso Acromático/metabolismo , Corpos Polares do Fuso/metabolismo , Segregação de Cromossomos , Microtúbulos/metabolismo
10.
Br J Haematol ; 186(4): 524-537, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31236939

RESUMO

Despite significant advances in the treatment of myeloid malignancies, many patients become resistant to therapy and ultimately succumb to their disease. Accumulating evidence over the past several years has suggested that the inadequacy of many leukaemia therapies results from their failure to target the leukaemic stem cell (LSC). For this reason, the LSC population currently represents the most critical target in the treatment of myeloid malignancies. However, while LSCs are ideal targets in the treatment of these diseases, they are also the most difficult population to target. This is due to both their heterogeneity within the LSC population, and also their phenotypic similarities with normal haematopoietic stem cells. This review will highlight the current landscape surrounding LSC biology in myeloid malignancies, with a focus on altered energy metabolism, and how that knowledge is being translated into clinical advances for the treatment of chronic and acute myeloid leukaemia and myelodysplastic syndromes.


Assuntos
Antineoplásicos/farmacologia , Metabolismo Energético , Leucemia Mieloide/etiologia , Leucemia Mieloide/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Antineoplásicos/uso terapêutico , Biomarcadores Tumorais , Ensaios Clínicos como Assunto , Resistencia a Medicamentos Antineoplásicos/genética , Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Humanos , Leucemia Mieloide/diagnóstico , Leucemia Mieloide/tratamento farmacológico , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/etiologia , Síndromes Mielodisplásicas/metabolismo , Síndromes Mielodisplásicas/terapia , Transdução de Sinais , Resultado do Tratamento
12.
PLoS Pathog ; 11(8): e1005134, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26317403

RESUMO

Morphological changes are critical for host colonisation in plant pathogenic fungi. These changes occur at specific stages of their pathogenic cycle in response to environmental signals and are mediated by transcription factors, which act as master regulators. Histone deacetylases (HDACs) play crucial roles in regulating gene expression, for example by locally modulating the accessibility of chromatin to transcriptional regulators. It has been reported that HDACs play important roles in the virulence of plant fungi. However, the specific environment-sensing pathways that control fungal virulence via HDACs remain poorly characterised. Here we address this question using the maize pathogen Ustilago maydis. We find that the HDAC Hos2 is required for the dimorphic switch and pathogenic development in U. maydis. The deletion of hos2 abolishes the cAMP-dependent expression of mating type genes. Moreover, ChIP experiments detect Hos2 binding to the gene bodies of mating-type genes, which increases in proportion to their expression level following cAMP addition. These observations suggest that Hos2 acts as a downstream component of the cAMP-PKA pathway to control the expression of mating-type genes. Interestingly, we found that Clr3, another HDAC present in U. maydis, also contributes to the cAMP-dependent regulation of mating-type gene expression, demonstrating that Hos2 is not the only HDAC involved in this control system. Overall, our results provide new insights into the role of HDACs in fungal phytopathogenesis.


Assuntos
Regulação Fúngica da Expressão Gênica/fisiologia , Histona Desacetilases/genética , Ustilago/genética , Ustilago/patogenicidade , Virulência/genética , Western Blotting , Imunoprecipitação da Cromatina , Conjugação Genética , Proteínas Fúngicas/genética , Genes Fúngicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Ustilago/enzimologia
13.
Plant Cell ; 25(11): 4676-90, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24280385

RESUMO

Secreted fungal effectors mediate plant-fungus pathogenic interactions. These proteins are typically N-glycosylated, a common posttranslational modification affecting their location and function. N-glycosylation consists of the addition, and subsequent maturation, of an oligosaccharide core in the endoplasmic reticulum (ER) and Golgi apparatus. In this article, we show that two enzymes catalyzing specific stages of this pathway in maize smut (Ustilago maydis), glucosidase I (Gls1) and glucosidase II ß-subunit (Gas2), are essential for its pathogenic interaction with maize (Zea mays). Gls1 is required for the initial stages of infection following appressorium penetration, and Gas2 is required for efficient fungal spreading inside infected tissues. While U. maydis Δgls1 cells induce strong plant defense responses, Δgas2 hyphae are able to repress them, showing that slight differences in the N-glycoprotein processing can determine the extent of plant-fungus interactions. Interestingly, the calnexin protein, a central element of the ER quality control system for N-glycoproteins in eukaryotic cells, is essential for avoiding plant defense responses in cells with defective N-glycoproteins processing. Thus, N-glycoprotein maturation and this conserved checkpoint appear to play an important role in the establishment of an initial biotrophic state with the plant, which allows subsequent colonization.


Assuntos
Retículo Endoplasmático/enzimologia , Proteínas Fúngicas/metabolismo , Glucosidases/metabolismo , Ustilago/metabolismo , Ustilago/patogenicidade , Zea mays/microbiologia , Calnexina/genética , Calnexina/metabolismo , Retículo Endoplasmático/metabolismo , Proteínas Fúngicas/genética , Glucosidases/genética , Glicoproteínas/metabolismo , Glicosilação , Interações Hospedeiro-Patógeno , Mutação , Filogenia , Doenças das Plantas/microbiologia , Ustilago/enzimologia , Zea mays/fisiologia
14.
Int J Mol Sci ; 16(9): 22280-98, 2015 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-26389888

RESUMO

The moss Physcomitrella patens is a suitable model plant to analyze the activation of defense mechanisms after pathogen assault. In this study, we show that Colletotrichum gloeosporioides isolated from symptomatic citrus fruit infects P. patens and cause disease symptoms evidenced by browning and maceration of tissues. After C. gloeosporioides infection, P. patens reinforces the cell wall by the incorporation of phenolic compounds and induces the expression of a Dirigent-protein-like encoding gene that could lead to the formation of lignin-like polymers. C. gloeosporioides-inoculated protonemal cells show cytoplasmic collapse, browning of chloroplasts and modifications of the cell wall. Chloroplasts relocate in cells of infected tissues toward the initially infected C. gloeosporioides cells. P. patens also induces the expression of the defense genes PAL and CHS after fungal colonization. P. patens reporter lines harboring the auxin-inducible promoter from soybean (GmGH3) fused to ß-glucuronidase revealed an auxin response in protonemal tissues, cauloids and leaves of C. gloeosporioides-infected moss tissues, indicating the activation of auxin signaling. Thus, P. patens is an interesting plant to gain insight into defense mechanisms that have evolved in primitive land plants to cope with microbial pathogens.


Assuntos
Ascomicetos/patogenicidade , Briófitas/microbiologia , Imunidade Vegetal , Briófitas/imunologia , Parede Celular/metabolismo , Cloroplastos/metabolismo , Ácidos Indolacéticos/metabolismo , Células Vegetais/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
15.
PLoS Pathog ; 8(3): e1002563, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22416226

RESUMO

The O-mannosyltransferase Pmt4 has emerged as crucial for fungal virulence in the animal pathogens Candida albicans or Cryptococcus neoformans as well as in the phytopathogenic fungus Ustilago maydis. Pmt4 O-mannosylates specific target proteins at the Endoplasmic Reticulum. Therefore a deficient O-mannosylation of these target proteins must be responsible for the loss of pathogenicity in pmt4 mutants. Taking advantage of the characteristics described for Pmt4 substrates in Saccharomyces cerevisiae, we performed a proteome-wide bioinformatic approach to identify putative Pmt4 targets in the corn smut fungus U. maydis and validated Pmt4-mediated glycosylation of candidate proteins by electrophoretic mobility shift assays. We found that the signalling mucin Msb2, which regulates appressorium differentiation upstream of the pathogenicity-related MAP kinase cascade, is O-mannosylated by Pmt4. The epistatic relationship of pmt4 and msb2 showed that both are likely to act in the same pathway. Furthermore, constitutive activation of the MAP kinase cascade restored appressorium development in pmt4 mutants, suggesting that during the initial phase of infection the failure to O-mannosylate Msb2 is responsible for the virulence defect of pmt4 mutants. On the other hand we demonstrate that during later stages of pathogenic development Pmt4 affects virulence independently of Msb2, probably by modifying secreted effector proteins. Pit1, a protein required for fungal spreading inside the infected leaf, was also identified as a Pmt4 target. Thus, O-mannosylation of different target proteins affects various stages of pathogenic development in U. maydis.


Assuntos
Proteínas Fúngicas/isolamento & purificação , Manosiltransferases/isolamento & purificação , Micotoxinas/isolamento & purificação , Doenças das Plantas/microbiologia , Ustilago/metabolismo , Fatores de Virulência/isolamento & purificação , Biologia Computacional/métodos , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Manosiltransferases/química , Manosiltransferases/metabolismo , Estrutura Molecular , Micotoxinas/química , Micotoxinas/metabolismo , Proteínas de Plantas/metabolismo , Proteômica , Relação Estrutura-Atividade , Fator de Transcrição Pit-1/metabolismo , Fatores de Virulência/química , Fatores de Virulência/metabolismo , Zea mays/microbiologia , Zea mays/ultraestrutura
16.
Plant Cell ; 23(4): 1654-65, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21478441

RESUMO

In the phytopathogenic fungus Ustilago maydis, the dikaryotic state dominates the period of growth occurring during the infectious phase. Dikaryons are cells in which two nuclei, one from each parent cell, share a single cytoplasm for a period of time without undergoing nuclear fusion. In fungal cells, maintenance of the dikaryotic state requires an intricate cell division process that often involves the formation of a structure known as the clamp connection as well as the sorting of one of the nuclei to this structure to ensure that each daughter dikaryon inherits a balance of each parental genome. Here, we describe an atypical role of the DNA damage checkpoint kinases Chk1 and Atr1 during pathogenic growth of U. maydis. We found that Chk1 and Atr1 collaborate to control cell cycle arrest during the induction of the virulence program in U. maydis and that Chk1 and Atr1 work together to control the dikaryon formation. These findings uncover a link between a widely conserved signaling cascade and the virulence program in a phytopathogen. We propose a model in which adjustment of the cell cycle by the Atr1-Chk1 axis controls fidelity in dikaryon formation. Therefore, Chk1 and Atr1 emerge as critical cell type regulators in addition to their roles in the DNA damage response.


Assuntos
Dano ao DNA , Transdução de Sinais , Ustilago/crescimento & desenvolvimento , Zea mays/microbiologia , Ciclo Celular , Núcleo Celular/metabolismo , Quinase 1 do Ponto de Checagem , Ativação Enzimática , Proteínas Fúngicas/metabolismo , Modelos Biológicos , Fosforilação , Proteínas Quinases/metabolismo , Ustilago/citologia , Ustilago/enzimologia , Ustilago/patogenicidade , Virulência
17.
Ann Coloproctol ; 40(3): 234-244, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38946094

RESUMO

PURPOSE: This study assessed the long-term outcomes and quality of life in patients who underwent sacral neuromodulation (SNM) due to low anterior resection syndrome (LARS). METHODS: This single-center retrospective study, conducted from 2005 to 2021, included 30 patients (21 men; median age, 70 years) who had undergone total mesorectal excision with stoma closure and had no recurrence at inclusion. All patients were diagnosed with LARS refractory to conservative treatment. We evaluated clinical and quality-of-life outcomes after SNM through a stool diary, Wexner score, LARS score, the Fecal Incontinence Quality of Life (FIQL) questionnaire, and EuroQol-5D (EQ-5D) questionnaire. RESULTS: Peripheral nerve stimulation was successful in all but one patient. Of the 29 patients who underwent percutaneous nerve evaluation, 17 (58.62%) responded well to SNM and received permanent implants. The median follow-up period was 48 months (range, 18-153 months). The number of days per week with fecal incontinence episodes decreased from a median of 7 (range, 2-7) to 0.38 (range, 0-1). The median number of bowel movements recorded in patient diaries fell from 5 (range, 4-12) to 2 (range, 1-6). The median Wexner score decreased from 18 (range, 13-20) to 6 (range, 0-16), while the LARS score declined from 38.5 (range, 37-42) to 19 (range, 4-28). The FIQL and EQ-5D questionnaires demonstrated enhanced quality of life. CONCLUSION: SNM may benefit patients diagnosed with LARS following rectal cancer surgery when conservative options have failed, and the treatment outcomes may possess long-term sustainability.

18.
Brain Behav ; 14(9): e3650, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39219244

RESUMO

INTRODUCTION: Despite the Rowland Universal Dementia Assessment Scale (RUDAS) having significant advantages as a cognitive screening tool, particularly for minority populations, the Mini-Mental State Examination (MMSE) test is the most widely used test for cognitive screening in Alzheimer's disease (AD). This study aimed to develop a conversion table to predict MMSE scores from observed RUDAS scores, allowing an easy-to-use method to compare both screening tests. METHODS: The equipercentile equating method was used to develop the conversion table using a training sample consisting of cognitively intact participants and individuals with early-stage AD. The resulting conversion table was validated in two samples, comprising participants from majority and minority populations assessed in Spanish. RESULTS: The conversion table demonstrated excellent reliability with intraclass correlation coefficients of.92 in both validation samples. CONCLUSION: This study provides a conversion table between RUDAS and MMSE scores, improving the comparability of these cognitive screening tools for use in clinical and research purposes.


Assuntos
Doença de Alzheimer , Testes de Estado Mental e Demência , Humanos , Testes de Estado Mental e Demência/normas , Feminino , Masculino , Idoso , Reprodutibilidade dos Testes , Doença de Alzheimer/diagnóstico , Idoso de 80 Anos ou mais , Grupos Minoritários , Demência/diagnóstico , Pessoa de Meia-Idade , Testes Neuropsicológicos/normas
19.
Methods Mol Biol ; 2818: 271-288, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39126481

RESUMO

During meiosis, transient associations between the nuclear envelope and telomeres transmit nuclear movements to chromosomes, enabling their pairing and recombination. Recent advances in the field of quantitative cell biology allow a large volume of information about the kinetics of these chromosome movements to be extracted and analyzed with the aim of identifying biologically relevant movement patterns. To this end, we have developed ChroMo, a freely available application for the unsupervised study of chromosome movements in fission yeast meiosis. ChroMo contains a set of time series algorithms to identify chromosome movement motifs that are not easily observable by direct human visualization and to establish causal relationships between phenotypes. In this chapter, we present a detailed protocol for the processing of raw live imaging data from fission yeast and its subsequent analysis in ChroMo.


Assuntos
Cromossomos Fúngicos , Meiose , Schizosaccharomyces , Schizosaccharomyces/genética , Cromossomos Fúngicos/genética , Algoritmos , Telômero/genética , Telômero/metabolismo , Software , Processamento de Imagem Assistida por Computador/métodos
20.
CNS Neurosci Ther ; 30(2): e14382, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-37501389

RESUMO

AIMS: The AT(N) classification system not only improved the biological characterization of Alzheimer's disease (AD) but also raised challenges for its clinical application. Unbiased, data-driven techniques such as clustering may help optimize it, rendering informative categories on biomarkers' values. METHODS: We compared the diagnostic and prognostic abilities of CSF biomarkers clustering results against their AT(N) classification. We studied clinical (patients from our center) and research (Alzheimer's Disease Neuroimaging Initiative) cohorts. The studied CSF biomarkers included Aß(1-42), Aß(1-42)/Aß(1-40) ratio, tTau, and pTau. RESULTS: The optimal solution yielded three clusters in both cohorts, significantly different in diagnosis, AT(N) classification, values distribution, and survival. We defined these three CSF groups as (i) non-defined or unrelated to AD, (ii) early stages and/or more delayed risk of conversion to dementia, and (iii) more severe cognitive impairment subjects with faster progression to dementia. CONCLUSION: We propose this data-driven three-group classification as a meaningful and straightforward approach to evaluating the risk of conversion to dementia, complementary to the AT(N) system classification.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Peptídeos beta-Amiloides , Proteínas tau , Disfunção Cognitiva/diagnóstico por imagem , Biomarcadores , Fragmentos de Peptídeos , Progressão da Doença
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