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1.
Proc Natl Acad Sci U S A ; 113(11): E1536-44, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26903630

RESUMO

In humans, the connection between sleep and mood has long been recognized, although direct molecular evidence is lacking. We identified two rare variants in the circadian clock gene PERIOD3 (PER3-P415A/H417R) in humans with familial advanced sleep phase accompanied by higher Beck Depression Inventory and seasonality scores. hPER3-P415A/H417R transgenic mice showed an altered circadian period under constant light and exhibited phase shifts of the sleep-wake cycle in a short light period (photoperiod) paradigm. Molecular characterization revealed that the rare variants destabilized PER3 and failed to stabilize PERIOD1/2 proteins, which play critical roles in circadian timing. Although hPER3-P415A/H417R-Tg mice showed a mild depression-like phenotype, Per3 knockout mice demonstrated consistent depression-like behavior, particularly when studied under a short photoperiod, supporting a possible role for PER3 in mood regulation. These findings suggest that PER3 may be a nexus for sleep and mood regulation while fine-tuning these processes to adapt to seasonal changes.


Assuntos
Afeto/fisiologia , Proteínas Circadianas Period/genética , Transtorno Afetivo Sazonal/genética , Idoso , Sequência de Aminoácidos , Animais , Relógios Circadianos/genética , Feminino , Humanos , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Proteínas Circadianas Period/metabolismo , Fotoperíodo , Estabilidade Proteica , Transtornos do Sono do Ritmo Circadiano/genética
2.
J Biol Chem ; 292(19): 7984-7993, 2017 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-28336531

RESUMO

The abundance of integral membrane proteins in the plasma membrane is determined by a dynamic balance between exocytosis and endocytosis, which can often be regulated by physiological stimuli. Here, we describe a mechanism that accounts for the ability of the peptide hormone vasopressin to regulate water excretion via a phosphorylation-dependent modulation of the PDZ domain-ligand interaction involving the water channel protein aquaporin-2. We discovered that the PDZ domain-containing protein Sipa1l1 (signal-induced proliferation-associated 1 like 1) binds to the cytoplasmic PDZ-ligand motif of aquaporin-2 and accelerates its endocytosis in the absence of vasopressin. Vasopressin-induced aquaporin-2 phosphorylation within the type I PDZ-ligand motif disrupted the interaction, in association with reduced aquaporin-2 endocytosis and prolonged plasma membrane aquaporin-2 retention. This phosphorylation-dependent alteration in the PDZ domain-ligand interaction was explained by 3D structural models, which showed a hormone-regulated mechanism that controls osmotic water transport and systemic water balance in mammals.


Assuntos
Aquaporina 2/química , Proteínas Ativadoras de GTPase/química , Vasopressinas/química , Animais , Aquaporina 2/genética , Endocitose , Proteínas Ativadoras de GTPase/genética , Células HEK293 , Humanos , Rim/metabolismo , Túbulos Renais Coletores/metabolismo , Ligantes , Camundongos , Modelos Moleculares , Fosforilação , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Transporte Proteico , Proteômica , RNA Interferente Pequeno/metabolismo , Serina/química , Água/química
3.
Proc Natl Acad Sci U S A ; 110(47): 19101-6, 2013 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-24191038

RESUMO

VLGR1 (very large G protein-coupled receptor 1), also known as MASS1 (monogenic audiogenic seizure susceptible 1), is an orphan G protein-coupled receptor that contains a large extracellular N terminus with 35 calcium-binding domains. A truncating mutation in the Mass1 gene causes autosomal recessive, sound-induced seizures in the Frings mouse. However, the function of MASS1 and the mechanism underlying Frings mouse epilepsy are not known. Here, we found that MASS1 protein is enriched in the myelinated regions of the superior and inferior colliculi, critical areas for the initiation and propagation of audiogenic seizures. Using a panel of myelin antibodies, we discovered that myelin-associated glycoprotein (MAG) expression is dramatically decreased in Frings mice. MASS1 inhibits the ubiquitylation of MAG, thus enhancing the stability of this protein, and the calcium-binding domains of MASS1 are essential for this regulation. Furthermore, MASS1 interacts with Gαs/Gαq and activates PKA and PKC in response to extracellular calcium. Suppression of signaling by MASS1 RNAi or a specific inhibitor abrogates MAG up-regulation. We postulate that MASS1 senses extracellular calcium and activates cytosolic PKA/PKC pathways to regulate myelination by means of MAG protein stability in myelin-forming cells of the auditory pathway. Further work is required to determine whether MAG dysregulation is a cause or consequence of audiogenic epilepsy and whether there are other pathways regulated by MASS1.


Assuntos
Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Epilepsia Reflexa/genética , Modelos Biológicos , Glicoproteína Associada a Mielina/metabolismo , Proteína Quinase C/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/fisiologia , Animais , Cálcio/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Epilepsia Reflexa/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Imuno-Histoquímica , Camundongos , Microscopia Eletrônica de Transmissão , Ubiquitinação
4.
Proc Natl Acad Sci U S A ; 110(43): 17468-73, 2013 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-24101522

RESUMO

Demyelinating disorders including leukodystrophies are devastating conditions that are still in need of better understanding, and both oligodendrocyte differentiation and myelin synthesis pathways are potential avenues for developing treatment. Overexpression of lamin B1 leads to leukodystrophy characterized by demyelination of the central nervous system, and microRNA-23 (miR-23) was found to suppress lamin B1 and enhance oligodendrocyte differentiation in vitro. Here, we demonstrated that miR-23a-overexpressing mice have increased myelin thickness, providing in vivo evidence that miR-23a enhances both oligodendrocyte differentiation and myelin synthesis. Using this mouse model, we explored possible miR-23a targets and revealed that the phosphatase and tensin homologue/phosphatidylinositol trisphosphate kinase/Akt/mammalian target of rapamycin pathway is modulated by miR-23a. Additionally, a long noncoding RNA, 2700046G09Rik, was identified as a miR-23a target and modulates phosphatase and tensin homologue itself in a miR-23a-dependent manner. The data presented here imply a unique role for miR-23a in the coordination of proteins and noncoding RNAs in generating and maintaining healthy myelin.


Assuntos
Diferenciação Celular/genética , Sistema Nervoso Central/metabolismo , MicroRNAs/genética , Bainha de Mielina/genética , Oligodendroglia/metabolismo , Animais , Western Blotting , Diferenciação Celular/fisiologia , Células Cultivadas , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/metabolismo , Microscopia Eletrônica , Bainha de Mielina/fisiologia , Bainha de Mielina/ultraestrutura , Oligodendroglia/citologia , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Transcriptoma
5.
Proc Natl Acad Sci U S A ; 109(50): 20679-84, 2012 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-23185022

RESUMO

Temporally restricted feeding (RF) can phase reset the circadian clocks in numerous tissues in mammals, contributing to altered timing of behavioral and physiological rhythms. However, little is known regarding the underlying molecular mechanism. Here we demonstrate a role for the gamma isotype of protein kinase C (PKCγ) in food-mediated entrainment of behavior and the molecular clock. We found that daytime RF reduced late-night activity in wild-type mice but not mice homozygous for a null mutation of PKCγ (PKCγ(-/-)). Molecular analysis revealed that PKCγ exhibited RF-induced changes in activation patterns in the cerebral cortex and that RF failed to substantially phase shift the oscillation of clock gene transcripts in the absence of PKCγ. PKCγ exerts effects on the clock, at least in part, by stabilizing the core clock component brain and muscle aryl hydrocarbon receptor nuclear translocator like 1 (BMAL1) and reducing its ubiquitylation in a deubiquitination-dependent manner. Taken together, these results suggest that PKCγ plays a role in food entrainment by regulating BMAL1 stability.


Assuntos
Fatores de Transcrição ARNTL/fisiologia , Ritmo Circadiano/fisiologia , Comportamento Alimentar/fisiologia , Proteína Quinase C/fisiologia , Fatores de Transcrição ARNTL/genética , Animais , Córtex Cerebral/fisiologia , Ritmo Circadiano/genética , Ingestão de Alimentos/genética , Ingestão de Alimentos/fisiologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Neurológicos , Mutação , Fotoperíodo , Proteína Quinase C/deficiência , Proteína Quinase C/genética , Estabilidade Proteica , Transdução de Sinais , Ubiquitinação
6.
Acad Radiol ; 31(7): 3004-3014, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38151383

RESUMO

Breast cancer is a multifactorial heterogeneous disease and the leading cause of cancer-related deaths in women; its diagnosis and treatment require clinical sensitivity and a comprehensive disciplinary research approach. The expression of different receptors on tumor cells not only provides the basis for molecular typing of breast cancer but also has a decisive role in the diagnosis, treatment, and prognosis of breast cancer. To date, immunohistochemistry (IHC), which uses invasive histological sampling, has been extensively used in clinical practice to analyze the status of receptors and to make an accurate diagnosis of breast cancer. As an invasive assay, IHC can provide important biological information on tumors at a single point in time, but cannot predict future changes (due to treatment or tumor mutations) without additional invasive procedures. These issues highlight the need to develop a non-invasive method for predicting receptor status. The emerging field of radiomics may offer a non-invasive approach to identification of receptor status without requiring biopsy. In this paper, we present a review of the latest research results in radiomics for predicting the status of breast cancer receptors, with potential important clinical applications.


Assuntos
Neoplasias da Mama , Humanos , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/metabolismo , Feminino , Imuno-Histoquímica , Biomarcadores Tumorais , Receptores de Estrogênio/metabolismo , Radiômica
7.
Cancer Med ; 13(8): e7128, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38659408

RESUMO

PURPOSE: Contrast-enhanced spectral imaging (CEM) is a new mammography technique, but its diagnostic value in dense breasts is still inconclusive. We did a systematic review and meta-analysis of studies evaluating the diagnostic performance of CEM for suspicious findings in dense breasts. MATERIALS AND METHODS: The PubMed, Embase, and Cochrane Library databases were searched systematically until August 6, 2023. Prospective and retrospective studies were included to evaluate the diagnostic performance of CEM for suspicious findings in dense breasts. The QUADAS-2 tool was used to evaluate the quality and risk of bias of the included studies. STATA V.16.0 and Review Manager V.5.3 were used to meta-analyze the included studies. RESULTS: A total of 10 studies (827 patients, 958 lesions) were included. These 10 studies reported the diagnostic performance of CEM for the workup of suspicious lesions in patients with dense breasts. The summary sensitivity and summary specificity were 0.95 (95% CI, 0.92-0.97) and 0.81 (95% CI, 0.70-0.89), respectively. Enhanced lesions, circumscribed margins, and malignancy were statistically correlated. The relative malignancy OR value of the enhanced lesions was 28.11 (95% CI, 6.84-115.48). The relative malignancy OR value of circumscribed margins was 0.17 (95% CI, 0.07-0.45). CONCLUSION: CEM has high diagnostic performance in the workup of suspicious findings in dense breasts, and when lesions are enhanced and have irregular margins, they are often malignant.


Assuntos
Densidade da Mama , Neoplasias da Mama , Meios de Contraste , Mamografia , Feminino , Humanos , Mama/diagnóstico por imagem , Mama/patologia , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Mamografia/métodos , Sensibilidade e Especificidade
8.
Nat Commun ; 15(1): 7169, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39169013

RESUMO

Protein complexes are fundamental to all cellular processes, so understanding their evolutionary history and assembly processes is important. Gene duplication followed by divergence is considered a primary mechanism for diversifying protein complexes. Nonetheless, to what extent assembly of present-day paralogous complexes has been constrained by their long evolutionary pathways and how cross-complex interference is avoided remain unanswered questions. Subunits of protein complexes are often stabilized upon complex formation, whereas unincorporated subunits are degraded. How such cooperative stability influences protein complex assembly also remains unclear. Here, we demonstrate that subcomplexes determined by cooperative stabilization interactions serve as building blocks for protein complex assembly. We further develop a protein stability-guided method to compare the assembly processes of paralogous complexes in cellulo. Our findings support that oligomeric state and the structural organization of paralogous complexes can be maintained even if their assembly processes are rearranged. Our results indicate that divergent assembly processes by paralogous complexes not only enable the complexes to evolve new functions, but also reinforce their segregation by establishing incompatibility against deleterious hybrid assemblies.


Assuntos
Complexos Multiproteicos , Complexos Multiproteicos/metabolismo , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Estabilidade Proteica , Evolução Molecular , Subunidades Proteicas/metabolismo , Subunidades Proteicas/química , Multimerização Proteica , Ligação Proteica , Duplicação Gênica
9.
Front Oncol ; 13: 1110657, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37333830

RESUMO

Objective: In order to explore the relationship between mammographic density of breast mass and its surrounding area and benign or malignant breast, this paper proposes a deep learning model based on C2FTrans to diagnose the breast mass using mammographic density. Methods: This retrospective study included patients who underwent mammographic and pathological examination. Two physicians manually depicted the lesion edges and used a computer to automatically extend and segment the peripheral areas of the lesion (0, 1, 3, and 5 mm, including the lesion). We then obtained the mammary glands' density and the different regions of interest (ROI). A diagnostic model for breast mass lesions based on C2FTrans was constructed based on a 7: 3 ratio between the training and testing sets. Finally, receiver operating characteristic (ROC) curves were plotted. Model performance was assessed using the area under the ROC curve (AUC) with 95% confidence intervals (CI), sensitivity, and specificity. Results: In total, 401 lesions (158 benign and 243 malignant) were included in this study. The probability of breast cancer in women was positively correlated with age and mass density and negatively correlated with breast gland classification. The largest correlation was observed for age (r = 0.47). Among all models, the single mass ROI model had the highest specificity (91.8%) with an AUC = 0.823 and the perifocal 5mm ROI model had the highest sensitivity (86.9%) with an AUC = 0.855. In addition, by combining the cephalocaudal and mediolateral oblique views of the perifocal 5 mm ROI model, we obtained the highest AUC (AUC = 0.877 P < 0.001). Conclusions: Deep learning model of mammographic density can better distinguish benign and malignant mass-type lesions in digital mammography images and may become an auxiliary diagnostic tool for radiologists in the future.

10.
Front Endocrinol (Lausanne) ; 12: 705499, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34421823

RESUMO

Breast cancer and osteoporosis are common diseases that affect the survival and quality of life in postmenopausal women. Women with breast cancer are more likely to develop osteoporosis than women without breast cancer due to certain factors that can affect both diseases simultaneously. For instance, estrogen and the receptor activator of nuclear factor-κB ligand (RANKL) play important roles in the occurrence and development of these two diseases. Moreover, chemotherapy and hormone therapy administered to breast cancer patients also increase the incidence of osteoporosis, and in recent years, neuropeptide Y (NPY) has also been found to impact breast cancer and osteoporosis.Y1 and Y5 receptors are highly expressed in breast cancer, and Y1 and Y2 receptors affect osteogenic response, thus potentially highlighting a potential new direction for treatment strategies. In this paper, the relationship between breast cancer and osteoporosis, the influence of NPY on both diseases, and the recent progress in the research and treatment of these diseases are reviewed.


Assuntos
Neoplasias da Mama/patologia , Neuropeptídeo Y/metabolismo , Osteoporose/patologia , Receptores de Neuropeptídeo Y/metabolismo , Neoplasias da Mama/metabolismo , Feminino , Humanos , Osteoporose/metabolismo , Prognóstico
11.
J Interferon Cytokine Res ; 40(2): 82-91, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31800346

RESUMO

Antiviral therapy for chronic hepatitis C (CHC) infection using pegylated interferon and ribavirin (PR) therapy can reduce the risk of hepatocellular carcinoma (HCC). Our study developed a new scoring method for predicting HCC risk after PR therapy. Between 2002 and 2016, 743 PR-treated patients with CHC were enrolled. Significant predictors for HCC were identified using multiple Cox regression analysis in study cohort: treatment age ≥60 years (hazard ratio [HR]: 2.04, 95% confidence interval [CI] = 1.3-3.7), pretreatment bilirubin ≥1.1 mg/dL (HR: 1.99, 95% CI = 1.08-3.67), α-fetoprotein ≥7.9 ng/mL (HR: 2.44, 95% CI = 1.16-5.32), no sustained virological response (SVR; HR: 1.91, 95% CI = 1.05-3.45), and baseline cirrhosis (HR: 4.45, 95% CI = 2.07-9.73). These predictors form the new HCC prediction scoring method with an area under the receiver operating characteristic curve of 0.884, sensitivity of 86.2%, and specificity of 74%. In patients with CHC and SVR, the cumulative incidence of HCC at 5 and 10 years was 16.7% and 30.4%, respectively, in patients with high risk scores and 1.2% and 4.2%, respectively, in patients with low risk scores (P < 0.001). Patients with SVR and high risk scores after viral eradication should remain under an intensive surveillance program for HCC. [Figure: see text].


Assuntos
Antivirais/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Interferons/uso terapêutico , Neoplasias Hepáticas/tratamento farmacológico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Carcinoma Hepatocelular/diagnóstico , Estudos de Coortes , Quimioterapia Combinada , Feminino , Hepatite C Crônica/diagnóstico , Humanos , Neoplasias Hepáticas/diagnóstico , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Estudos Retrospectivos , Fatores de Risco
12.
Clin Chim Acta ; 489: 75-82, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30471249

RESUMO

BACKGROUND: We evaluated liver fibrosis in patients with chronic hepatitis B (CHB) and mildly raised alanine transaminase (ALT) activities between 1-2 times the upper limit of normal (ULN) which was near the threshold for initiating treatment. METHODS: Nomogram-Fibrosis and Nomogram-Cirrhosis were elaborated with variables independently associated with significant fibrosis and cirrhosis determined by multivariate logistic regression. Calibration, receiver operator characteristic (ROC) and decision curves were applied to comparing nomograms with aspartate aminotransferase (AST) to platelet count (PLT) ratio index (APRI), age-AST-PLT-ALT index (FIB-4) and liver stiffness measurement (LSM). RESULTS: The Nomogram-Fibrosis was constructed with LSM, PLT, and gamma-glutamyl transpeptidase (GGT). Nomogram-Cirrhosis contained one more variable of age other than Nomogram-Fibrosis. The calibration demonstrated that the assessments of significant fibrosis or cirrhosis by nomograms were in line with liver biopsy. The AUROC of Nomogram-Fibrosis was 0.788, lager than APRI (0.586), FIB-4 (0.656) and LSM (0.735). The AUROC of Nomogram-Cirrhosis was 0.889, larger than APRI (0.642), FIB-4 (0.725) and LSM (0.837). Furthermore, the decision curve analysis suggested the most net benefits were provided by the nomograms. CONCLUSIONS: Nomogram-Fibrosis and Nomogram-Cirrhosis could be promising tools for recognizing significant fibrosis and cirrhosis for CHB patients with mild raised ALT activities.


Assuntos
Hepatite B/complicações , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Fígado/patologia , Fenômenos Mecânicos , Nomogramas , Adulto , Fenômenos Biomecânicos , Biópsia , Calibragem , Feminino , Humanos , Fígado/virologia , Cirrose Hepática/virologia , Masculino , Curva ROC , Estudos Retrospectivos
13.
Front Physiol ; 10: 1308, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681015

RESUMO

Aquaporin-2 (AQP2) is a molecular water channel protein responsible for water reabsorption by the kidney collecting ducts. Many water balance disorders are associated with defects in AQP2 gene expression regulated by the peptide hormone vasopressin. Here, we studied roles of Elf3 (E26 transformation-specific (Ets)-related transcription factor 3) in AQP2 gene expression in the collecting duct cells (mpkCCD). Vasopressin increased AQP2 mRNA and protein levels without affecting AQP2 mRNA degradation, indicative of transcriptional regulation. Elf3 knockdown and overexpression, respectively, reduced and increased AQP2 gene expression under basal and vasopressin-stimulated conditions. However, the vasopressin-to-basal ratios of AQP2 gene expression levels remained constant, indicating that Elf3 does not directly mediate vasopressin response but modulates the level of AQP2 gene expression inducible by vasopressin. The Elf3-modulated AQP2 gene expression was associated with AQP2 promoter activity, in line with Elf3's ability to bind an Ets element in the AQP2 promoter. Mutation in the Ets element reduced both basal and vasopressin-stimulated AQP2 promoter activity, again without affecting vasopressin-to-basal ratios of the AQP2 promoter activity. Lithium chloride reduced both Elf3 and AQP2 mRNA in the mpkCCD cells as well as in mouse kidney inner medulla. We conclude that Elf3 modulates AQP2 promoter activity thereby gauging vasopressin-inducible AQP2 gene expression levels. Our data provide a potential explanation to lithium-induced nephrogenic diabetes insipidus where lithium reduces Elf3 and hence AQP2 abundance.

14.
Nat Prod Res ; 32(21): 2510-2515, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29313378

RESUMO

Two new diketopiperazine alkaloids, named protuboxepin C (1) and protuboxepin D (2), which contain D-Phe residue and oxepin ring, were isolated from EtOAc extract of sponge-derived fungus Aspergillus sp SCSIO XWS02F40. Their structures were elucidated by 1D, 2D NMR and HRESIMS dates, and their absolute configurations were confirmed by single crystal X-ray diffraction experiments and CD analyses. The in vitro cytotoxicity of these two new compounds was further evaluated using A549 and Hela cell lines.


Assuntos
Alcaloides/química , Aspergillus/química , Dicetopiperazinas/química , Piperazinas/química , Células A549 , Alcaloides/isolamento & purificação , Animais , Cristalografia por Raios X , Dicetopiperazinas/isolamento & purificação , Células HeLa , Humanos , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Piperazinas/isolamento & purificação , Poríferos/microbiologia
16.
Transl Neurodegener ; 3(1): 4, 2014 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-24495672

RESUMO

Adult-onset autosomal dominant leukodystrophy (ADLD) is a progressive and fatal hereditary demyelination disorder characterized initially by autonomic dysfunction and loss of myelin in the central nervous system (CNS). Majority of ADLD is caused by a genomic duplication of the nuclear lamin B1 gene (LMNB1) encoding lamin B1 protein, resulting in increased gene dosage in brain tissue. In vitro, excessive lamin B1 at the cellular level reduces transcription of myelin genes, leading to premature arrest of oligodendrocyte differentiation. Murine models of ADLD overexpressing LMNB1 exhibited age-dependent motor deficits and myelin defects, which are associated with reduced occupancy of the Yin Yang 1 transcription factor at the promoter region of the proteolipid protein gene. Lamin B1 overexpression mediates oligodendrocyte cell-autonomous neuropathology in ADLD and suggests lamin B1 as an important regulator of myelin formation and maintenance during aging. Identification of microRNA-23 (miR-23) as a negative regulator of lamin B1 can ameliorate the consequences of excessive lamin B1 at the cellular level. miR-23a-overexpressing mice display enhanced oligodendrocyte differentiation and myelin synthesis. miR-23a targets include a protein coding transcript PTEN (phosphatase and tensin homolog on chromosome 10), and a long noncoding RNA (2700046G09Rik), indicating a unique role for miR-23a in the coordination of proteins and noncoding RNAs in generating and maintaining healthy myelin. Here, we provide a concise review of the current literature on clinical presentations of ADLD and how lamin B1 affects myelination and other developmental processes. Moreover, we address the emerging role of non-coding RNAs (ncRNAs) in modulating gene networks, specifically investigating miR-23 as a potential target for the treatment of ADLD and other demyelinating disorders.

17.
Elife ; 3: e02981, 2014 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-25182847

RESUMO

Circadian clocks serve as internal pacemakers that influence many basic homeostatic processes; consequently, the expression and function of their components are tightly regulated by intricate networks of feedback loops that fine-tune circadian processes. Our knowledge of these components and pathways is far from exhaustive. In recent decades, the nuclear envelope has emerged as a global gene regulatory machine, although its role in circadian regulation has not been explored. We report that transcription of the core clock component BMAL1 is positively modulated by the inner nuclear membrane protein MAN1, which directly binds the BMAL1 promoter and enhances its transcription. Our results establish a novel connection between the nuclear periphery and circadian rhythmicity, therefore bridging two global regulatory systems that modulate all aspects of bodily functions.


Assuntos
Fatores de Transcrição ARNTL/genética , Relógios Circadianos/genética , Regulação da Expressão Gênica , Proteínas de Membrana/genética , Proteínas Nucleares/genética , Fatores de Transcrição ARNTL/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Proteínas de Ligação a DNA , Células HEK293 , Humanos , Lamina Tipo B/genética , Lamina Tipo B/metabolismo , Proteínas de Membrana/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
J Clin Invest ; 123(6): 2719-29, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23676464

RESUMO

Adult-onset autosomal-dominant leukodystrophy (ADLD) is a progressive and fatal neurological disorder characterized by early autonomic dysfunction, cognitive impairment, pyramidal tract and cerebellar dysfunction, and white matter loss in the central nervous system. ADLD is caused by duplication of the LMNB1 gene, which results in increased lamin B1 transcripts and protein expression. How duplication of LMNB1 leads to myelin defects is unknown. To address this question, we developed a mouse model of ADLD that overexpresses lamin B1. These mice exhibited cognitive impairment and epilepsy, followed by age-dependent motor deficits. Selective overexpression of lamin B1 in oligodendrocytes also resulted in marked motor deficits and myelin defects, suggesting these deficits are cell autonomous. Proteomic and genome-wide transcriptome studies indicated that lamin B1 overexpression is associated with downregulation of proteolipid protein, a highly abundant myelin sheath component that was previously linked to another myelin-related disorder, Pelizaeus-Merzbacher disease. Furthermore, we found that lamin B1 overexpression leads to reduced occupancy of Yin Yang 1 transcription factor at the promoter region of proteolipid protein. These studies identify a mechanism by which lamin B1 overexpression mediates oligodendrocyte cell-autonomous neuropathology in ADLD and implicate lamin B1 as an important regulator of myelin formation and maintenance during aging.


Assuntos
Lamina Tipo B/metabolismo , Oligodendroglia/patologia , Doença de Pelizaeus-Merzbacher/metabolismo , Animais , Axônios/metabolismo , Axônios/patologia , Modelos Animais de Doenças , Marcha Atáxica/metabolismo , Marcha Atáxica/patologia , Marcha Atáxica/fisiopatologia , Predisposição Genética para Doença , Humanos , Lamina Tipo B/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora , Proteína Proteolipídica de Mielina/genética , Bainha de Mielina/metabolismo , Bainha de Mielina/patologia , Oligodendroglia/metabolismo , Doença de Pelizaeus-Merzbacher/patologia , Doença de Pelizaeus-Merzbacher/fisiopatologia , Regiões Promotoras Genéticas , Ligação Proteica , Teste de Desempenho do Rota-Rod , Convulsões/metabolismo , Convulsões/patologia , Convulsões/fisiopatologia , Fator de Transcrição YY1/metabolismo
19.
Biotechnol Prog ; 28(1): 206-14, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21936063

RESUMO

In this study, we developed composite chitosan beads combining various metal ions, including Ni(2+), Cu(2+), Zn(2+), and Fe(2+), for direct adsorption of enterovirus 71 (EV71). The metal-ion species had significant effects on the adsorption capacity of beads. Among these metal ion-composite chitosan beads, Ni(2+)-chitosan beads exhibited the best adsorption capacity of EV71. Using a concentration of 0.01-M Ni(2+) was found to best provide for bead formation and EV71 adsorption. The adsorption of EV71 for Ni(2+)-chitosan beads at neutral or alkaline pH was favored. Under a competitive condition with albumin proteins, Ni(2+)-chitosan beads exhibited significant capacity of EV71 adsorption in culture media. The adsorption of EV71 on the Ni(2+)-chitosan beads was attributed to the strong binding between Ni(2+) ions chelated to the surface amino acid of EV71 capsids and Ni(2+) ions chelated on the chitosan materials. Moreover, the adsorbed EV71 retained its antigenicity and infectivity after desorption. The Ni(2+)-chitosan beads exhibit a promising application to EV71 adsorption and removal.


Assuntos
Quitosana/química , Enterovirus Humano A/metabolismo , Metais/metabolismo , Adsorção , Quelantes , Cobre/química , Concentração de Íons de Hidrogênio , Ferro/química , Cinética , Níquel/química , Zinco/química
20.
Dis Model Mech ; 2(3-4): 178-88, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19259393

RESUMO

Duplication of the gene encoding lamin B1 (LMNB1) with increased mRNA and protein levels has been shown to cause severe myelin loss in the brains of adult-onset autosomal dominant leukodystrophy patients. Similar to many neurodegenerative disorders, patients with adult-onset autosomal dominant leukodystrophy are phenotypically normal until adulthood and the defect is specific to the central nervous system despite the ubiquitous expression pattern of lamin B1. We set out to dissect the molecular mechanisms underlying this demyelinating phenotype. Increased lamin B1 expression results in disturbances of inner nuclear membrane proteins, chromatin organization and nuclear pore transport in vitro. It also leads to premature arrest of oligodendrocyte differentiation, which might be caused by reduced transcription of myelin genes and by mislocalization of myelin proteins. We identified the microRNA miR-23 as a negative regulator of lamin B1 that can ameliorate the consequences of excessive lamin B1 at the cellular level. Our results indicate that regulation of lamin B1 is important for myelin maintenance and that miR-23 contributes to this process, at least in part, by downregulating lamin B1, therefore establishing novel functions of lamin B1 and miR-23 in the regulation of oligodendroglia development and myelin formation in vitro.


Assuntos
Lamina Tipo B/genética , Lamina Tipo B/fisiologia , MicroRNAs/genética , Bainha de Mielina/fisiologia , Oligodendroglia/fisiologia , Animais , Linhagem Celular , Membrana Celular/metabolismo , Núcleo Celular/metabolismo , Cromatina/metabolismo , Duplicação Gênica , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Modelos Biológicos , Bainha de Mielina/metabolismo , Fenótipo
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