Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Proc Natl Acad Sci U S A ; 118(24)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34099554

RESUMO

Differential concentrations of phytohormone trigger distinct outputs, which provides a mechanism for the plasticity of plant development and an adaptation strategy among plants to changing environments. However, the underlying mechanisms of the differential responses remain unclear. Here we report that a high concentration of auxin, distinct from the effect of low auxin concentration, enhances abscisic acid (ABA) responses in Arabidopsis thaliana, which partially relies on TRANS-MEMBERANE KINASE 1 (TMK1), a key regulator in auxin signaling. We show that high auxin and TMK1 play essential and positive roles in ABA signaling through regulating ABA INSENSITIVE 1 and 2 (ABI1/2), two negative regulators of the ABA pathway. TMK1 inhibits the phosphatase activity of ABI2 by direct phosphorylation of threonine 321 (T321), a conserved phosphorylation site in ABI2 proteins, whose phosphorylation status is important for both auxin and ABA responses. This TMK1-dependent auxin signaling in the regulation of ABA responses provides a possible mechanism underlying the high auxin responses in plants and an alternative mechanism involved in the coordination between auxin and ABA signaling.


Assuntos
Ácido Abscísico/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Ácidos Indolacéticos/metabolismo , Fosfoproteínas Fosfatases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Epistasia Genética , Fosforilação , Fosfotreonina/metabolismo , Ligação Proteica
2.
Plant J ; 109(3): 675-692, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34783109

RESUMO

C4 plants partition photosynthesis enzymes between the bundle sheath (BS) and the mesophyll (M) cells for the better delivery of CO2 to RuBisCO and to reduce photorespiration. To better understand how C4 photosynthesis is regulated at the transcriptional level, we performed RNA-seq, ATAC-seq, ChIP-seq and Bisulfite-seq (BS-seq) on BS and M cells isolated from maize leaves. By integrating differentially expressed genes with chromatin features, we found that chromatin accessibility coordinates with epigenetic features, especially H3K27me3 modification and CHH methylation, to regulate cell type-preferentially enriched gene expression. Not only the chromatin-accessible regions (ACRs) proximal to the genes (pACRs) but also the distal ACRs (dACRs) are determinants of cell type-preferentially enriched expression. We further identified cell type-preferentially enriched motifs, e.g. AAAG for BS cells and TGACC/T for M cells, and determined their corresponding transcription factors: DOFs and WRKYs. The complex interaction between cis and trans factors in the preferential expression of C4 genes was also observed. Interestingly, cell type-preferentially enriched gene expression can be fine-tuned by the coordination of multiple chromatin features. Such coordination may be critical in ensuring the cell type-specific function of key C4 genes. Based on the observed cell type-preferentially enriched expression pattern and coordinated chromatin features, we predicted a set of functionally unknown genes, e.g. Zm00001d042050 and Zm00001d040659, to be potential key C4 genes. Our findings provide deep insight into the architectures associated with C4 gene expression and could serve as a valuable resource to further identify the regulatory mechanisms present in C4 species.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Cromatina/genética , Cromatina/metabolismo , Células do Mesofilo/metabolismo , Zea mays/crescimento & desenvolvimento , Zea mays/genética , Produtos Agrícolas/genética , Produtos Agrícolas/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Fotossíntese , Células Vegetais
3.
Plant Physiol ; 190(1): 500-515, 2022 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-35758633

RESUMO

Leaf angle is an important agronomic trait determining maize (Zea mays) planting density and light penetration into the canopy and contributes to the yield gain in modern maize hybrids. However, little is known about the molecular mechanisms underlying leaf angle beyond the ZmLG1 (liguleless1) and ZmLG2 (Liguleless2) genes. In this study, we found that the transcription factor (TF) ZmBEH1 (BZR1/BES1 homolog gene 1) is targeted by ZmLG2 and regulates leaf angle formation by influencing sclerenchyma cell layers on the adaxial side. ZmBEH1 interacted with the TF ZmBZR1 (Brassinazole Resistant 1), whose gene expression was also directly activated by ZmLG2. Both ZmBEH1 and ZmBZR1 are bound to the promoter of ZmSCL28 (SCARECROW-LIKE 28), a third TF that influences leaf angle. Our study demonstrates regulatory modules controlling leaf angle and provides gene editing targets for creating optimal maize architecture suitable for dense planting.


Assuntos
Locos de Características Quantitativas , Zea mays , Organogênese Vegetal , Folhas de Planta/genética , Fatores de Transcrição/genética , Zea mays/genética
4.
Mov Disord ; 38(12): 2258-2268, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37990409

RESUMO

BACKGROUND: Patients with Parkinson's disease (PD) have consistently demonstrated brain structure abnormalities, indicating the presence of shared etiological and pathological processes between PD and brain structures; however, the genetic relationship remains poorly understood. OBJECTIVE: The aim of this study was to investigate the extent of shared genetic architecture between PD and brain structural phenotypes (BSPs) and to identify shared genomic loci. METHODS: We used the summary statistics from genome-wide association studies to conduct MiXeR and conditional/conjunctional false discovery rate analyses to investigate the shared genetic signatures between PD and BSPs. Subsequent expression quantitative trait loci mapping in the human brain and enrichment analyses were also performed. RESULTS: MiXeR analysis identified genetic overlap between PD and various BSPs, including total cortical surface area, average cortical thickness, and specific brain volumetric structures. Further analysis using conditional false discovery rate (FDR) identified 21 novel PD risk loci on associations with BSPs at conditional FDR < 0.01, and the conjunctional FDR analysis demonstrated that PD shared several genomic loci with certain BSPs at conjunctional FDR < 0.05. Among the shared loci, 16 credible mapped genes showed high expression in the brain tissues and were primarily associated with immune function-related biological processes. CONCLUSIONS: We confirmed the polygenic overlap with mixed directions of allelic effects between PD and BSPs and identified multiple shared genomic loci and risk genes, which are likely related to immune-related biological processes. These findings provide insight into the complex genetic architecture associated with PD. © 2023 International Parkinson and Movement Disorder Society.


Assuntos
Estudo de Associação Genômica Ampla , Doença de Parkinson , Humanos , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/genética , Predisposição Genética para Doença/genética , Fenótipo , Encéfalo/diagnóstico por imagem , Polimorfismo de Nucleotídeo Único/genética , Loci Gênicos
5.
J Headache Pain ; 24(1): 111, 2023 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-37592229

RESUMO

BACKGROUND: While previous genome-wide association studies (GWAS) have identified multiple risk variants for migraine, there is a lack of evidence about how these variants contribute to the development of migraine. We employed an integrative pipeline to efficiently transform genetic associations to identify causal genes for migraine. METHODS: We conducted a proteome-wide association study (PWAS) by combining data from the migraine GWAS data with proteomic data from the human brain and plasma to identify proteins that may play a role in the risk of developing migraine. We also combined data from GWAS of migraine with a novel joint-tissue imputation (JTI) prediction model of 17 migraine-related human tissues to conduct transcriptome-wide association studies (TWAS) together with the fine mapping method FOCUS to identify disease-associated genes. RESULTS: We identified 13 genes in the human brain and plasma proteome that modulate migraine risk by regulating protein abundance. In addition, 62 associated genes not reported in previous migraine TWAS studies were identified by our analysis of migraine using TWAS and fine mapping. Five genes including ICA1L, TREX1, STAT6, UFL1, and B3GNT8 showed significant associations with migraine at both the proteome and transcriptome, these genes are mainly expressed in ependymal cells, neurons, and glial cells, and are potential target genes for prevention of neuronal signaling and inflammatory responses in the pathogenesis of migraine. CONCLUSIONS: Our proteomic and transcriptome findings have identified disease-associated genes that may give new insights into the pathogenesis and potential therapeutic targets for migraine.


Assuntos
Transtornos de Enxaqueca , Proteoma , Humanos , Proteoma/genética , Estudo de Associação Genômica Ampla , Proteômica , Transcriptoma , Transtornos de Enxaqueca/genética
6.
BMC Med Inform Decis Mak ; 22(1): 3, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34986813

RESUMO

BACKGROUND: TOAST subtype classification is important for diagnosis and research of ischemic stroke. Limited by experience of neurologist and time-consuming manual adjudication, it is a big challenge to finish TOAST classification effectively. We propose a novel active deep learning architecture to classify TOAST. METHODS: To simulate the diagnosis process of neurologists, we drop the valueless features by XGB algorithm and rank the remaining ones. Utilizing active learning framework, we propose a novel causal CNN, in which it combines with a mixed active selection criterion to optimize the uncertainty of samples adaptively. Meanwhile, KL-focal loss derived from the enhancement of Focal loss by KL regularization is introduced to accelerate the iterative fine-tuning of the model. RESULTS: To evaluate the proposed method, we construct a dataset which consists of totally 2310 patients. In a series of sequential experiments, we verify the effectiveness of each contribution by different evaluation metrics. Experimental results show that the proposed method achieves competitive results on each evaluation metric. In this task, the improvement of AUC is the most obvious, reaching 77.4. CONCLUSIONS: We construct a backbone causal CNN to simulate the neurologist process of that could enhance the internal interpretability. The research on clinical data also indicates the potential application value of this model in stroke medicine. Future work we would consider various data types and more comprehensive patient types to achieve fully automated subtype classification.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Algoritmos , Humanos , AVC Isquêmico/diagnóstico , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia
7.
Microb Cell Fact ; 20(1): 133, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256737

RESUMO

BACKGROUND: Flonicamid (N-cyanomethyl-4-trifluoromethylnicotinamide, FLO) is a new type of pyridinamide insecticide that regulates insect growth. Because of its wide application in agricultural production and high solubility in water, it poses potential risks to aquatic environments and food chain. RESULTS: In the present study, Ensifer adhaerens CGMCC 6315 was shown to efficiently transform FLO into N-(4-trifluoromethylnicotinoyl) glycinamide (TFNG-AM) via a hydration pathway mediated by two nitrile hydratases, PnhA and CnhA. In pure culture, resting cells of E. adhaerens CGMCC 6315 degraded 92% of 0.87 mmol/L FLO within 24 h at 30 °C (half-life 7.4 h). Both free and immobilized (by gel beads, using calcium alginate as a carrier) E. adhaerens CGMCC 6315 cells effectively degraded FLO in surface water. PnhA has, to our knowledge, the highest reported degradation activity toward FLO, Vmax = 88.7 U/mg (Km = 2.96 mmol/L). Addition of copper ions could increase the enzyme activity of CnhA toward FLO by 4.2-fold. Structural homology modeling indicated that residue ß-Glu56 may be important for the observed significant difference in enzyme activity between PnhA and CnhA. CONCLUSIONS: Application of E. adhaerens may be a good strategy for bioremediation of FLO in surface water. This work furthers our understanding of the enzymatic mechanisms of biodegradation of nitrile-containing insecticides and provides effective transformation strategies for microbial remediation of FLO contamination.


Assuntos
Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Hidroliases/metabolismo , Inseticidas/metabolismo , Niacinamida/análogos & derivados , Rhizobiaceae/enzimologia , Rhizobiaceae/metabolismo , Niacinamida/metabolismo , Nitrilas/metabolismo
8.
BMC Neurol ; 21(1): 404, 2021 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-34674659

RESUMO

BACKGROUND: Lower prognostic nutritional index (PNI) is related to the poor prognosis of cardiovascular diseases. However, little is known about PNI and its relationship with the prognosis of cerebral venous sinus thrombosis (CVST). METHODS: CVST patients were retrospectively identified from January 2013 till June 2019. Patients in the acute / subacute phase were selected as subjects. Poor prognosis was defined as a modified Rankin Scale (mRS) of 3-6. Multivariate logistic regression analysis was used to confirm if lower PNI was associated with a poor prognosis. RESULTS: A total of 297 subjects with follow-up data were enrolled. Thirty-three (11.1%) had a poor outcome. Multivariate logistic regression analysis suggested that PNI was an important predictive factor of poor outcome in acute/subacute CVST (odds ratio, 0.903; 95% CI, 0.833-0.978; P = 0.012). The optimal cut-off value for predicting the poor prognosis of PNI was 44.2. Kaplan-Meier analysis and log-rank test suggested that the lower the PNI value, the higher the mortality rate (P < 0.001). In addition, the nomogram that was set up showed that lower PNI was an index of poor prognosis. The c-index for acute/subacute patients with CVST was 0.872. CONCLUSION: Lower PNI is correlated with a higher risk of adverse clinical outcomes in patients with acute/subacute CVST.


Assuntos
Avaliação Nutricional , Trombose dos Seios Intracranianos , Humanos , Estimativa de Kaplan-Meier , Prognóstico , Estudos Retrospectivos , Trombose dos Seios Intracranianos/diagnóstico por imagem
9.
Int J Mol Sci ; 22(20)2021 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-34681824

RESUMO

Chloroplasts play an essential role in plant growth and development. Any factors affecting chloroplast development will lead to abnormal plant growth. Here, we characterized a new maize mutant, albino seedling mutant 81647 (as-81647), which exhibits an entirely albino phenotype in leaves and eventually died before the three-leaf stage. Transmission electron microscopy (TEM) demonstrated that the chloroplast thylakoid membrane was impaired and the granum lamellae significantly decreased in as-81647. Map-based cloning and transgenic analysis confirmed that PPR647 encodes a new chloroplast protein consisting of 11 pentratricopeptide repeat domains. Quantitative real-time PCR (qRT-PCR) assays and transcriptome analysis (RNA-seq) showed that the PPR647 mutation significantly disrupted the expression of PEP-dependent plastid genes. In addition, RNA splicing and RNA editing of multiple chloroplast genes showed severe defects in as-81647. These results indicated that PPR647 is crucial for RNA editing, RNA splicing of chloroplast genes, and plays an essential role in chloroplast development.


Assuntos
Cloroplastos/fisiologia , Proteínas de Plantas/genética , Edição de RNA , Splicing de RNA , RNA de Cloroplastos/metabolismo , Zea mays/genética , Zea mays/metabolismo , Cloroplastos/ultraestrutura , Regulação da Expressão Gênica de Plantas , Genes de Cloroplastos , Mutação , Fenótipo , Filogenia , Folhas de Planta/citologia , Proteínas de Plantas/metabolismo , Domínios Proteicos , Plântula/genética , Plântula/metabolismo , Tilacoides/fisiologia , Tilacoides/ultraestrutura
10.
Int Microbiol ; 23(2): 225-232, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31410668

RESUMO

An N2-fixing bacterium, Ensifer meliloti CGMCC 7333, has been reported to degrade the cyano-containing neonicotinoid insecticides acetamiprid and thiacloprid using a nitrile hydratase (NHase). Here, the bioconversion of indole-3-acetonitrile (IAN) by E. meliloti, Escherichia coli overexpressing the NHase, and purified recombinant NHase was studied. E. meliloti converted IAN to the product indole-3-acetamide (IAM), and no nitrilase or amidase activities, or indole-3-acetic acid formation, were detected. Whole cells of E. meliloti converted IAN from the initial content of 6.41 to 0.06 mmol/L in 48 h. Meanwhile, forming 5.99 mmol/L IAM, the molar conversion of 94.4%. E. coli Rosetta overexpressing the NHase from E. meliloti produced 4.46 mmol/L IAM in 5 min, with a conversion rate of 91.1%. The purified NHase had a Vmax for IAN conversion of 294.28 U/mg. Adding 2% and 10% (v/v) dichloromethane to 50 mmol/L sodium phosphate buffer containing 200 mg/L IAN increased the NHase activity by 26.8% and 11.5% respectively, while the addition of 20% hexane had no inhibitory effect on IAN bioconversion. E. meliloti shows high NHase activity without forming a byproduct carboxylic acid, and its tolerance of dichloromethane and hexane increases its potential for application in the green biosynthesis of high-value amide compounds.


Assuntos
Hidroliases/biossíntese , Indóis/metabolismo , Rhizobiaceae/enzimologia , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/metabolismo , Biodegradação Ambiental , Poluentes Ambientais/metabolismo , Escherichia coli/metabolismo , Hidroliases/metabolismo , Ácidos Indolacéticos/metabolismo , Inseticidas/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo
12.
Appl Environ Microbiol ; 84(16)2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-29884755

RESUMO

Variovorax is a metabolically diverse genus of plant growth-promoting rhizobacteria (PGPR) that engages in mutually beneficial interactions between plants and microbes. Unlike most PGPR, Variovorax cannot synthesize the phytohormone indole-3-acetic acid (IAA) via tryptophan. However, we found that Variovorax boronicumulans strain CGMCC 4969 can produce IAA using indole-3-acetonitrile (IAN) as the precursor. Thus, in the present study, the IAA synthesis mechanism of V. boronicumulans CGMCC 4969 was investigated. V. boronicumulans CGMCC 4969 metabolized IAN to IAA through both a nitrilase-dependent pathway and a nitrile hydratase (NHase) and amidase-dependent pathway. Cobalt enhanced the metabolic flux via the NHase/amidase, by which IAN was rapidly converted to indole-3-acetamide (IAM) and in turn to IAA. IAN stimulated metabolic flux via the nitrilase, by which IAN was rapidly converted to IAA. Subsequently, the IAA was degraded. V. boronicumulans CGMCC 4969 can use IAN as the sole carbon and nitrogen source for growth. Genome sequencing confirmed the IAA synthesis pathways. Gene cloning and overexpression in Escherichia coli indicated that NitA has nitrilase activity and IamA has amidase activity to respectively transform IAN and IAM to IAA. Interestingly, NitA showed a close genetic relationship with the nitrilase of the phytopathogen Pseudomonas syringae Quantitative PCR analysis indicated that the NHase/amidase system is constitutively expressed, whereas the nitrilase is inducible. The present study helps our understanding of the versatile functions of Variovorax nitrile-converting enzymes that mediate IAA synthesis and the interactions between plants and these bacteria.IMPORTANCE We demonstrated that Variovorax boronicumulans CGMCC 4969 has two enzymatic systems-nitrilase and nitrile hydratase/amidase-that convert indole-3-acetonitrile (IAN) to the important plant hormone indole-3-acetic acid (IAA). The two IAA synthesis systems have very different regulatory mechanisms, affecting the IAA synthesis rate and duration. The nitrilase was induced by IAN, which was rapidly converted to IAA; subsequently, IAA was rapidly consumed for cell growth. The nitrile hydratase (NHase) and amidase system was constitutively expressed and slowly but continuously synthesized IAA. In addition to synthesizing IAA from IAN, CGMCC 4969 has a rapid IAA degradation system, which would be helpful for a host plant to eliminate redundant IAA. This study indicates that the plant growth-promoting rhizobacterium V. boronicumulans CGMCC 4969 has the potential to be used by host plants to regulate the IAA level.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Comamonadaceae/enzimologia , Comamonadaceae/genética , Ácidos Indolacéticos/metabolismo , Indóis/metabolismo , Aminoidrolases/metabolismo , Arabidopsis/microbiologia , Biotransformação , Clonagem Molecular , Genoma Bacteriano , Redes e Vias Metabólicas , Reguladores de Crescimento de Plantas/metabolismo , Análise de Sequência de DNA
13.
Int J Mol Sci ; 19(7)2018 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-29941860

RESUMO

In the previous study, we screened a novel lncRNA-ITGB2-AS1, which was down-regulated by bone morphogenetic protein 9 (BMP9) in breast cancer cell. Studying ITGB2-AS1 will lay the foundation for the exploring mechanism of the BMP9 inhibitory effect on breast cancer. The expression analysis related to ITGB2-AS1 in clinical samples was conducted on online websites. The overexpression plasmid or siRNA fragment was transfected into breast cancer cells to alter its gene expression. The MTT assay and flow cytometry were used to measure cell viability and cell cycle. Additionally, cell migration and invasion were detected by wound healing and transwell assay. The results of biological function experiments showed that ITGB2-AS1 could promote the migration and invasion of breast cancer. Furthermore, ITGB2-AS1 increased the mRNA and protein expression of ITGB2. Consistent with ITGB2-AS1, ITGB2 exerted the promotion effect on the migration and invasion of breast cancer and activated integrin-related FAK signaling. The OL plasmid expressing the truncation of ITGB2-AS1, which was complementary to ITGB2, was essential for activation of FAK signaling. In conclusion, LncRNA ITGB2-AS1 could promote the migration and invasion of breast cancer cells by up-regulating ITGB2.


Assuntos
Neoplasias da Mama/genética , Integrina beta3/genética , Invasividade Neoplásica/genética , RNA Longo não Codificante/genética , Neoplasias da Mama/patologia , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica/patologia , RNA Mensageiro/genética , Ativação Transcricional/genética , Transfecção
14.
Int J Mol Sci ; 19(4)2018 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-29642505

RESUMO

As the most common malignant tumor of the urinary system worldwide, the bladder tumor has a high mortality rate, which is mainly due to its onset of concealment. Therefore, research into novel diagnostic markers and treatment of bladder cancer is urgently needed. BMP9 (Bone morphogenetic protein 9) is a member of BMP, which belongs to the TGF-ß (transforming growth factor-ß) superfamily. It has been associated with multiple tumors. We found that BMP9 is highly expressed in bladder cancer cells and it could significantly promote the proliferation and migration of bladder cancer cells. In the study of the mechanism of this effect, we found that BMP9 can increase the expression of lncRNA UCA1 (Urothelial cancer associated 1) through phosphorylated AKT. The promoting effect of BMP9 on bladder cancer cells was rescued after interfering with UCA1 in BMP9 overexpressed bladder cancer cells both in vitro and in vivo. Our research confirms that BMP9 promotes the proliferation and migration of bladder cancer cells through up-regulated lncRNA UCA1. It also shows that BMP9 is a novel diagnostic marker and a potential therapeutic target in bladder cancer.


Assuntos
Movimento Celular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fatores de Diferenciação de Crescimento/metabolismo , RNA Longo não Codificante/genética , Neoplasias da Bexiga Urinária/metabolismo , Animais , Linhagem Celular Tumoral , Fator 2 de Diferenciação de Crescimento , Fatores de Diferenciação de Crescimento/genética , Humanos , Masculino , Camundongos , Camundongos Nus , RNA Longo não Codificante/metabolismo , Regulação para Cima , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
15.
Hum Mol Genet ; 23(4): 1013-24, 2014 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-24113144

RESUMO

Gordon Holmes syndrome (GHS) is a rare Mendelian neurodegenerative disorder characterized by ataxia and hypogonadism. Recently, it was suggested that disordered ubiquitination underlies GHS though the discovery of exome mutations in the E3 ligase RNF216 and deubiquitinase OTUD4. We performed exome sequencing in a family with two of three siblings afflicted with ataxia and hypogonadism and identified a homozygous mutation in STUB1 (NM_005861) c.737C→T, p.Thr246Met, a gene that encodes the protein CHIP (C-terminus of HSC70-interacting protein). CHIP plays a central role in regulating protein quality control, in part through its ability to function as an E3 ligase. Loss of CHIP function has long been associated with protein misfolding and aggregation in several genetic mouse models of neurodegenerative disorders; however, a role for CHIP in human neurological disease has yet to be identified. Introduction of the Thr246Met mutation into CHIP results in a loss of ubiquitin ligase activity measured directly using recombinant proteins as well as in cell culture models. Loss of CHIP function in mice resulted in behavioral and reproductive impairments that mimic human ataxia and hypogonadism. We conclude that GHS can be caused by a loss-of-function mutation in CHIP. Our findings further highlight the role of disordered ubiquitination and protein quality control in the pathogenesis of neurodegenerative disease and demonstrate the utility of combining whole-exome sequencing with molecular analyses and animal models to define causal disease polymorphisms.


Assuntos
Anormalidades Múltiplas/enzimologia , Ataxia Cerebelar/enzimologia , Hormônio Liberador de Gonadotropina/deficiência , Hipogonadismo/enzimologia , Ubiquitina-Proteína Ligases/genética , Anormalidades Múltiplas/genética , Adolescente , Sequência de Aminoácidos , Animais , Células COS , Ataxia Cerebelar/genética , Cerebelo/metabolismo , Cerebelo/patologia , Chlorocebus aethiops , Feminino , Estudos de Associação Genética , Hormônio Liberador de Gonadotropina/genética , Humanos , Hipogonadismo/genética , Masculino , Camundongos , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Fenótipo , Ubiquitina-Proteína Ligases/deficiência , Adulto Jovem
16.
Neurol Sci ; 37(11): 1853-1855, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27465029

RESUMO

Anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) encephalitis positive for additional onconeural antibodies is rarely reported. Here we report the clinical features of a patient who developed limbic encephalitis with both glutamate receptor 2 (GluR2) and collapsin response mediator protein 5 (CRMP5) antibodies. Brain magnetic resonance imaging revealed multifocal encephalopathy. Chest computed tomography showed a highly suspicious malignant thymoma. He experienced rapid neurological deterioration during hospitalization. This report indicates that the clinical diversity of anti-AMPAR encephalitis and the presence of onconeural antibodies may lead to poor prognosis.


Assuntos
Doenças Autoimunes do Sistema Nervoso , Encefalite , Proteínas do Tecido Nervoso/imunologia , Receptores de Glutamato/imunologia , Timoma/diagnóstico por imagem , Neoplasias do Timo/diagnóstico por imagem , Adulto , Doenças Autoimunes do Sistema Nervoso/imunologia , Doenças Autoimunes do Sistema Nervoso/patologia , Doenças Autoimunes do Sistema Nervoso/fisiopatologia , Encefalite/imunologia , Encefalite/patologia , Encefalite/fisiopatologia , Humanos , Hidrolases , Masculino , Proteínas Associadas aos Microtúbulos
17.
Int J Neurosci ; 126(12): 1071-6, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26643368

RESUMO

PURPOSE: Cerebral cavernous malformations (CCMs) are vascular anomalies predominantly in the central nervous system but may include lesions in other tissues, such as the retina, skin and liver. The main clinical manifestations include seizures, hemorrhage, recurrent headaches and focal neurological deficits. Previous studies of familial CCMs (FCCMs) have mainly reported in Hispanic and Caucasian cases. Here, we report on FCCMs in a Chinese family further characterized by a novel CCM1 gene mutation. MATERIALS AND METHODS: We investigated clinical and neuroradiological features of a Chinese family of 30 members. Furthermore, we used exome capture sequencing to identify the causing gene. The CCM1 mRNA expression level in three patients of the family and 10 wild-type healthy individuals were detected by real-time quantitative polymerase chain reaction (real-time RT-PCR). RESULTS: Brain magnetic resonance imaging demonstrated multiple intracranial lesions in seven members. The clinical manifestation of CCM was found in five of these cases, including recurrent headaches, weakness, hemorrhage and seizures. Moreover, we identified a novel nonsense mutation c.1159G>T (p. E387*) in the CCM1 gene in the pedigree. Based on real-time RT-PCR results, we have found that the CCM1 mRNA expression level in three patients was reduced by 35% than that in wild-type healthy individuals. CONCLUSIONS: Our finding suggests that the novel nonsense mutation c.1159G>T in CCM1 gene is associated with FCCM, and that CCM1 haploinsufficiency may be the underlying mechanism of CCMs. Furthermore, it also demonstrates that exome capture sequencing is an efficient and direct diagnostic tool to identify causes of genetically heterogeneous diseases.


Assuntos
Saúde da Família , Hemangioma Cavernoso do Sistema Nervoso Central/genética , Proteína KRIT1/genética , Mutação/genética , Adulto , Povo Asiático , Análise Mutacional de DNA , Feminino , Hemangioma Cavernoso do Sistema Nervoso Central/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Adulto Jovem
18.
J Neurol ; 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38847847

RESUMO

BACKGROUND: The current understandings of the relationship between air pollution (AP), greenspace exposure and Parkinson's Disease (PD) remain inconclusive. METHODS: We engaged 441,462 participants from the UK Biobank who were not diagnosed with PD. Utilizing Cox proportional hazard regression model, relationships between AP [nitrogen dioxide (NO2), and nitrogen oxides (NOX), particulate matter < 2.5 µm in aerodynamic diameter(PM2.5), coarse particulate matter between 2.5 µm and 10 µm in aerodynamic diameter(PM2.5-10), particulate matter < 10 µm in aerodynamic diameter(PM10)], greenspace exposure, and PD risk were determined independently. Our analyses comprised three models, adjusted for covariates, and affirmed through six sensitivity analyses to bolster the robustness of our findings. Moreover, mediation analysis was deployed to discern the mediating effect of AP between greenspaces and PD. RESULTS: During a median follow-up of 12.23 years (5,574,293 person-years), there were 3,293 PD events. Each interquartile (IQR) increment in NO2 and PM10 concentrations were associated with 10% and 8% increase in PD onset risk, while the increases in NOX, PM2.5 and PM2.5-10 were not associated with PD risk. Additionally, greenspace may safeguard by reducing NO2 and PM10 levels, with the effect mediated by NO2 and PM10 in greenspace-PD relationship. CONCLUSION: Our findings indicate that an IQR increase in ambient NO2 and PM10 concentrations was associated with risk of PD development, while other pollutants (NOX, PM2.5 and PM2.5-10) were not associated with PD risk. Firstly, we find that augmented exposure to greenspace was associated with the lower PD risk by reducing NO2 and PM10 levels.

19.
J Atheroscler Thromb ; 2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38644203

RESUMO

AIM: Atrial cardiomyopathy (ACM) is characterized by atrial dysfunction. This study aims to assess the prognostic significance of ACM in patients with noncardioembolic stroke (NCS). METHODS: Patients with NCS within seven days of onset were prospectively enrolled between January 2019 and December 2020. ACM was defined as either an N-terminal pro-brain natriuretic peptide (NT-pro BNP) >250 pg/ml or a P-terminal force in precordial lead V1 (PTFV1) ≥ 5000µV·ms. A poor functional outcome was determined as a score of 3-6 on the modified Rankin Scale (mRS) within a 2-year follow-up period. Logistic regression and Cox regression analyses were employed to examine the relationship between ACM and the long-term prognosis of patients with NCS. RESULTS: A total of 1,346 patients were enrolled, of whom 299 (22.2%) patients were diagnosed with ACM. A total of 207(15.4%) patients experienced a poor functional outcome, and 58 (4.3%) patients died. A multivariate logistic regression analysis indicated that ACM was significantly associated with a poor functional outcome in NCS patients [adjusted odds ratio (aOR): 2.01; 95% confidence interval (CI): 1.42-2.87; p<0.001]. Additionally, a multivariate Cox regression analysis showed that an NT-pro BNP >250 pg/ml was significantly associated with an increased risk of all-cause mortality [adjusted hazard ratio (aHR), 2.51; 95% CI: 1.42-4.43; p=0.001]. CONCLUSIONS: ACM may serve as a novel predictor of a poor long-term functional outcome in patients with NCS. Elevated NT-pro BNP levels (>250 pg/ml) were found to be associated with a higher risk of all-cause mortality. These findings warrant further validation in multicenter studies.

20.
Stroke ; 44(5): 1244-8, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23532014

RESUMO

BACKGROUND AND PURPOSE: The Age, Blood Pressure, Clinical Features, Duration, and Diabetes plus Dual TIA (ABCD(3)-I) score is recommended to predict the risk of early stroke after transient ischemic attack. The aim of this study was to validate the predictive value of the ABCD(3)-I score and compare the accuracy of the Age, Blood Pressure, Clinical Features, Duration, and Diabetes (ABCD(2)) and ABCD(3)-I scores in a Chinese population. METHODS: Data were prospectively collected from patients who had transient ischemic attack, as defined by the World Health Organization time-based criteria. ABCD(2) and ABCD(3)-I scores were available within 7 days of the index transient ischemic attack. The predictive outcome was stroke occurrence at 90 days. The receiver-operating characteristic curves were plotted, and the C statistics were calculated as a measure of predictive ability. The comparison of the area under the receiver-operating characteristic curve (area under the curve) was performed by Z test. RESULTS: Among 239 eligible patients, the mean age was 57.4±13.32 years, and 40.2% of the patients were women. The incidence of stroke at 90 days was 12.1%, which ranged from 0% in patients with lower ABCD(3)-I scores (0-3) to 40.91% in those with higher scores of 8 to 13 (P for trend <0.0001). Moreover, the C statistic of ABCD(3)-I scores (0.825; 95% confidence interval, 0.752-0.898) was statistically higher than that of ABCD(2) scores (0.694; 95% confidence interval, 0.601-0.786; P<0.001). CONCLUSIONS: The ABCD(3)-I score had a higher predictive value than the ABCD(2) score for assessing the risk of early stroke after transient ischemic attack in a Chinese population.


Assuntos
Ataque Isquêmico Transitório/complicações , Acidente Vascular Cerebral/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Ataque Isquêmico Transitório/epidemiologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Risco , Medição de Risco , Índice de Gravidade de Doença , Acidente Vascular Cerebral/epidemiologia , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA