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1.
Cell ; 140(2): 222-34, 2010 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-20141836

RESUMEN

N-methyl-D-aspartate (NMDA) receptors constitute a major subtype of glutamate receptors at extrasynaptic sites that link multiple intracellular catabolic processes responsible for irreversible neuronal death. Here, we report that cerebral ischemia recruits death-associated protein kinase 1 (DAPK1) into the NMDA receptor NR2B protein complex in the cortex of adult mice. DAPK1 directly binds with the NMDA receptor NR2B C-terminal tail consisting of amino acid 1292-1304 (NR2B(CT)). A constitutively active DAPK1 phosphorylates NR2B subunit at Ser-1303 and in turn enhances the NR1/NR2B receptor channel conductance. Genetic deletion of DAPK1 or administration of NR2B(CT) that uncouples an activated DAPK1 from an NMDA receptor NR2B subunit in vivo in mice blocks injurious Ca(2+) influx through NMDA receptor channels at extrasynaptic sites and protects neurons against cerebral ischemic insults. Thus, DAPK1 physically and functionally interacts with the NMDA receptor NR2B subunit at extrasynaptic sites and this interaction acts as a central mediator for stroke damage.


Asunto(s)
Proteínas Reguladoras de la Apoptosis/metabolismo , Isquemia Encefálica/metabolismo , Proteínas Quinasas Dependientes de Calcio-Calmodulina/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Accidente Cerebrovascular/metabolismo , Animales , Proteínas Reguladoras de la Apoptosis/antagonistas & inhibidores , Proteínas Reguladoras de la Apoptosis/genética , Encéfalo/metabolismo , Encéfalo/patología , Isquemia Encefálica/tratamiento farmacológico , Proteínas Quinasas Dependientes de Calcio-Calmodulina/antagonistas & inhibidores , Proteínas Quinasas Dependientes de Calcio-Calmodulina/genética , Muerte Celular , Proteínas Quinasas Asociadas a Muerte Celular , Ratones , Neuronas/citología , Neuronas/metabolismo , Péptidos/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/patología , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/genética , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo
2.
Artículo en Inglés | MEDLINE | ID: mdl-37551942

RESUMEN

OBJECTIVES: Autoantibodies against MDA5 serve as a biomarker for dermatomyositis (DM) and a risk factor for interstitial lung disease (ILD). MDA5 is a protein responsible for sensing RNA virus infection and activating signalling pathways against it. However, little is known about antigen epitopes on MDA5 autoantibodies. We aimed to determine the interaction of the MDA5 autoantibody-antigen epitope. METHODS: Cell-based assays (CBAs), immunoprecipitation-immunoblot assays, and various immunoblotting techniques were used in the study. RESULTS: We demonstrate that DM patient autoantibodies recognize MDA5 epitopes in a native conformation-dependent manner. Furthermore, we identified the central helicase domain formed by Hel1, Hel2i, Hel2, and pincer (3Hel) as the major epitopes. As proof of principle, the purified 3Hel efficiently absorbed MDA5 autoantibodies from patient sera through immunoprecipitation-immunoblot assay. CONCLUSION: Our study uncovers the nature of antigen epitopes on MDA5 and provides guidance for diagnosis and targeted therapeutic approach development.

3.
J Sex Med ; 20(8): 1078-1084, 2023 07 31.
Artículo en Inglés | MEDLINE | ID: mdl-37295940

RESUMEN

BACKGROUND: Sexual activity appears to have protective effects on overall and cardiovascular health. AIM: We hypothesized that decreased sexual frequency would be an early predictor of all-cause mortality in young and middle-aged patients (20 to 59 years old) with hypertension. METHODS: A total of 4565 patients with hypertension (55.6% men; mean [SD] age 40.60 [10.81] years) who had completed a sexual behavior questionnaire were enrolled from the National Health and Nutrition Examination Survey of 2005 to 2014. Cox proportional hazards models and Kaplan-Meier survival curves were used to evaluate the relationship between sexual frequency and all-cause mortality. OUTCOMES: The outcome measure for this study is the relationship between sexual frequency and all-cause mortality in young and middle-aged patients with hypertension. RESULTS: During the 68-month median follow-up period, 109 (2.39%) patients died from any cause. After full adjustment for potential confounders, sexual frequency was an independent predictive factor for all-cause mortality in young and middle-aged patients with hypertension. A marital status difference was identified in the subgroup analysis: among patients with a sexual frequency of <12 times/year, only married patients had higher risks of all-cause mortality than the 12-51 times/year group (HR, 0.476, 95% CI, 0.235-0.963, P < .05) and > 51 (HR, 0.452, 95% CI, 0.213-0.961, P < .05) times/year groups. The association of sexual frequency and all-cause mortality was nonlinear. CLINICAL IMPLICATIONS: Increased frequency of sexual activity may have protective effects on overall health and quality of life in patients with hypertension. STRENGTHS AND LIMITATIONS: To our knowledge this is the first observational investigation performed to evaluate the correlation between sexual frequency and all-cause mortality in patients with hypertension. A limitation of the study is that the participants in our analysis were between the ages of 20 and 59 years, and this patient sample may not reflect possible outcomes for patients of other age groups. CONCLUSION: The association between lower frequency of sexual intercourse and greater all-cause mortality was significant in young and middle-aged patients with hypertension in the United States.


Asunto(s)
Enfermedades Cardiovasculares , Hipertensión , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven , Estudios de Cohortes , Hipertensión/epidemiología , Encuestas Nutricionales , Calidad de Vida , Conducta Sexual , Estados Unidos/epidemiología
4.
J Biol Chem ; 294(37): 13657-13670, 2019 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-31341023

RESUMEN

Hematopoietic stem cells (HSCs)/progenitor cells (HPCs) are generated from hemogenic endothelial cells (HECs) during the endothelial-to-hematopoietic transition (EHT); however, the underlying mechanism remains poorly understood. Here, using an array of approaches, including CRSPR/Cas9 gene knockouts, RNA-Seq, ChIP-Seq, ATAC-Seq etc., we report that vitamin C (Vc) is essential in HPC generation during human pluripotent stem cell (hPSC) differentiation in defined culture conditions. Mechanistically, we found that the endothelial cells generated in the absence of Vc fail to undergo the EHT because of an apparent failure in opening up genomic loci essential for hematopoiesis. Under Vc deficiency, these loci exhibited abnormal accumulation of histone H3 trimethylation at Lys-27 (H3K27me3), a repressive histone modification that arose because of lower activities of demethylases that target H3K27me3. Consistently, deletion of the two H3K27me3 demethylases, Jumonji domain-containing 3 (JMJD3 or KDM6B) and histone demethylase UTX (UTX or KDM6A), impaired HPC generation even in the presence of Vc. Furthermore, we noted that Vc and jmjd3 are also important for HSC generation during zebrafish development. Together, our findings reveal an essential role for Vc in the EHT for hematopoiesis, and identify KDM6-mediated chromatin demethylation as an important regulatory mechanism in hematopoietic cell differentiation.


Asunto(s)
Ácido Ascórbico/metabolismo , Células Madre Hematopoyéticas/metabolismo , Histona Demetilasas/metabolismo , Animales , Animales Modificados Genéticamente , Diferenciación Celular/genética , Diferenciación Celular/fisiología , Cromatina/metabolismo , Cromatina/fisiología , Desmetilación , Células Endoteliales/metabolismo , Histona Demetilasas/genética , Histonas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/metabolismo , Lisina/metabolismo , Metilación , Células Madre Pluripotentes/metabolismo , Pez Cebra/genética
5.
J Biol Chem ; 293(12): 4445-4455, 2018 03 23.
Artículo en Inglés | MEDLINE | ID: mdl-29386354

RESUMEN

During neurogenesis, neural patterning is a critical step during which neural progenitor cells differentiate into neurons with distinct functions. However, the molecular determinants that regulate neural patterning remain poorly understood. Here we optimized the "dual SMAD inhibition" method to specifically promote differentiation of human pluripotent stem cells (hPSCs) into forebrain and hindbrain neural progenitor cells along the rostral-caudal axis. We report that neural patterning determination occurs at the very early stage in this differentiation. Undifferentiated hPSCs expressed basal levels of the transcription factor orthodenticle homeobox 2 (OTX2) that dominantly drove hPSCs into the "default" rostral fate at the beginning of differentiation. Inhibition of glycogen synthase kinase 3ß (GSK3ß) through CHIR99021 application sustained transient expression of the transcription factor NANOG at early differentiation stages through Wnt signaling. Wnt signaling and NANOG antagonized OTX2 and, in the later stages of differentiation, switched the default rostral cell fate to the caudal one. Our findings have uncovered a mutual antagonism between NANOG and OTX2 underlying cell fate decisions during neural patterning, critical for the regulation of early neural development in humans.


Asunto(s)
Diferenciación Celular , Linaje de la Célula , Proteína Homeótica Nanog/metabolismo , Células-Madre Neurales/citología , Neuronas/citología , Factores de Transcripción Otx/metabolismo , Células Madre Pluripotentes/citología , Tipificación del Cuerpo , Células Cultivadas , Regulación del Desarrollo de la Expresión Génica , Humanos , Colículos Inferiores/citología , Colículos Inferiores/metabolismo , Núcleos del Rafe Mesencefálico/citología , Núcleos del Rafe Mesencefálico/metabolismo , Células-Madre Neurales/metabolismo , Neurogénesis , Neuronas/metabolismo , Células Madre Pluripotentes/metabolismo , Prosencéfalo/citología , Prosencéfalo/metabolismo , Rombencéfalo/citología , Rombencéfalo/metabolismo
6.
Neurobiol Learn Mem ; 165: 106859, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-29698767

RESUMEN

Highly expressed in the mammalian brain and widely distributed across the genome, MeCP2 is a key player in recognizing modified DNA and interpreting the epigenetic information encoded in different DNA methylation/hydroxymethylation patterns. Alterations in sequence or copy number of the X-linked human MECP2 gene cause either Rett syndrome (RTT) or MECP2 duplication syndrome. Alterations in MECP2 levels have also been identified in patients with autism. To fully understand the significant role of MECP2 in regulating the development and function of the nervous system, it is important to study all aspects of MeCP2 function. Stimulus-induced MeCP2 phosphorylation has been shown to influence the proliferation and differentiation of neural progenitor cells, synaptic scaling, excitatory synaptogenesis, and animal behavior. However, all of the previous functional evidence is from studying phospho-dead mutations. In addition, the relationship between phosphorylation events at multiple sites on the MeCP2 protein is not well understood. Here, we report the generation of a phospho-mimic knockin Mecp2 mouse line. At the synaptic and behavioral levels, the phospho-mimic Mecp2 mice show phenotypes opposite to those observed in phospho-dead mutation at the same phosphorylation site. Moreover, we report opposite phenotypes between phospho-mutants of two sites on the MeCP2 protein. Our new data further confirm the functional significance of specific MeCP2 phosphorylation event and support the opposing regulatory role between different MeCP2 phosphorylation events.


Asunto(s)
Conducta Animal , Proteína 2 de Unión a Metil-CpG/fisiología , Células-Madre Neurales/fisiología , Sinapsis/fisiología , Animales , Western Blotting , Diferenciación Celular , Línea Celular , Células Cultivadas , Femenino , Técnicas de Sustitución del Gen , Hipocampo/citología , Masculino , Proteína 2 de Unión a Metil-CpG/metabolismo , Ratones , Ratones Endogámicos C57BL , Microscopía Confocal , Neuronas/fisiología , Técnicas de Placa-Clamp , Fosforilación
7.
Proc Natl Acad Sci U S A ; 111(38): 13805-10, 2014 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-25201954

RESUMEN

Physical stimuli can act in either a synergistic or antagonistic manner to regulate cell fate decisions, but it is less clear whether insoluble signals alone can direct human pluripotent stem (hPS) cell differentiation into specialized cell types. We previously reported that stiff materials promote nuclear localization of the Yes-associated protein (YAP) transcriptional coactivator and support long-term self-renewal of hPS cells. Here, we show that even in the presence of soluble pluripotency factors, compliant substrata inhibit the nuclear localization of YAP and promote highly efficient differentiation of hPS cells into postmitotic neurons. In the absence of neurogenic factors, the effective substrata produce neurons rapidly (2 wk) and more efficiently (>75%) than conventional differentiation methods. The neurons derived from substrate induction express mature markers and possess action potentials. The hPS differentiation observed on compliant surfaces could be recapitulated on stiff surfaces by adding small-molecule inhibitors of F-actin polymerization or by depleting YAP. These studies reveal that the matrix alone can mediate differentiation of hPS cells into a mature cell type, independent of soluble inductive factors. That mechanical cues can override soluble signals suggests that their contributions to early tissue development and lineage commitment are profound.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular , Matriz Extracelular/química , Neuronas/metabolismo , Fosfoproteínas/metabolismo , Células Madre Pluripotentes/metabolismo , Actinas/metabolismo , Células Cultivadas , Humanos , Neuronas/citología , Células Madre Pluripotentes/citología , Factores de Tiempo , Factores de Transcripción , Proteínas Señalizadoras YAP
8.
Hum Mol Genet ; 23(11): 2968-80, 2014 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-24419315

RESUMEN

The disease mechanism of Rett syndrome (RTT) is not well understood. Studies in RTT mouse models have suggested a non-cell-autonomous role for astrocytes in RTT pathogenesis. However, it is not clear whether this is also true for human RTT astrocytes. To establish an in vitro human RTT model, we previously generated isogenic induced pluripotent stem cell (iPSC) lines from several RTT patients carrying different disease-causing mutations. Here, we show that these RTT iPSC lines can be efficiently differentiated into astroglial progenitors and glial fibrillary acidic protein-expressing (GFAP(+)) astrocytes that maintain isogenic status, that mutant RTT astrocytes carrying three different RTT mutations and their conditioned media have adverse effects on the morphology and function of wild-type neurons and that the glial effect on neuronal morphology is independent of the intrinsic neuronal deficit in mutant neurons. Moreover, we show that both insulin-like growth factor 1 (IGF-1) and GPE (a peptide containing the first 3 amino acids of IGF-1) are able to partially rescue the neuronal deficits caused by mutant RTT astrocytes. Our findings confirm the critical glial contribution to RTT pathology, reveal potential cellular targets of IGF-1 therapy and further validate patient-specific iPSCs and their derivatives as valuable tools to study RTT disease mechanism.


Asunto(s)
Astrocitos/citología , Diferenciación Celular , Células Madre Pluripotentes Inducidas/citología , Proteína 2 de Unión a Metil-CpG/genética , Neuronas/metabolismo , Síndrome de Rett/genética , Astrocitos/metabolismo , Células Cultivadas , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Proteína 2 de Unión a Metil-CpG/metabolismo , Mutación , Neuronas/citología , Síndrome de Rett/metabolismo , Síndrome de Rett/fisiopatología
9.
J Neurosci ; 32(37): 12841-7, 2012 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-22973007

RESUMEN

MeCP2 (methyl CpG binding protein 2) is a key player in recognizing methylated DNA and interpreting the epigenetic information encoded in different DNA methylation patterns. The functional significance of MeCP2 to the mammalian nervous system is highlighted by the discovery that mutations in the MECP2 gene cause Rett syndrome (RTT), a devastating neurological disease that shares many features with autism. Synaptic scaling is a form of non-Hebbian homeostatic plasticity that allows neurons to regulate overall excitability in response to changes in network neuronal activity levels. While it is known that neuronal activity can induce phosphorylation of MeCP2 and that MeCP2 can regulate synaptic scaling, the molecular link between MeCP2 phosphorylation and synaptic scaling remains undefined. We show here that MeCP2 phosphorylation is specifically required for bicuculline-induced synaptic scaling down in mouse hippocampal neurons and this phenotype is mediated by mGluR5 (metabotropic glutamate receptor 5). Our results reveal an important function of MeCP2 in regulating neuronal homeostasis and may eventually help us understand how MECP2 mutations cause RTT.


Asunto(s)
Proteína 2 de Unión a Metil-CpG/metabolismo , Plasticidad Neuronal/fisiología , Neuronas/fisiología , Receptores de Glutamato Metabotrópico/metabolismo , Transmisión Sináptica/fisiología , Animales , Células Cultivadas , Ratones , Ratones Noqueados , Ratones Transgénicos , Fosforilación , Receptor del Glutamato Metabotropico 5
10.
J Biol Chem ; 287(27): 22948-58, 2012 Jun 29.
Artículo en Inglés | MEDLINE | ID: mdl-22577135

RESUMEN

Previous studies suggest that up-regulation of Ras signaling in neurons promotes gliosis and astrocytoma formation in a cell nonautonomous manner. However, the underlying mechanisms remain unknown. To address this question, we generated compound mice (LSL Kras G12D/+;CamKII-Cre) that express oncogenic Kras from its endogenous locus in postmitotic neurons after birth. These mice developed progressive gliosis, which is associated with hyperactivation of Ras signaling pathways. Microarray analysis identified S100A8 and S100A9 as two secreted molecules that are significantly overexpressed in mutant cortices. In contrast to their usual predominant expression in myeloid cells, we found that overexpression of S100A8 and S100A9 in the mutant cortex is primarily in neurons. This neuronal expression pattern is associated with increased infiltration of microglia in mutant cortex. Moreover, purified S100A8-S100A9 but not S100A8 or S100A9 alone promotes growth of primary astrocytes in vitro through both TLR4 and receptor of advanced glycation end product receptors. In summary, our results identify overexpression of S100A8-S100A9 in neurons as an early step in oncogenic Kras-induced gliosis. These molecules expressed in nonhematopoietic cells may be involved in tumorigenesis at a stage much earlier than what has been reported previously.


Asunto(s)
Calgranulina A/genética , Calgranulina B/genética , Gliosis/genética , Neuronas/fisiología , Proteínas Proto-Oncogénicas/genética , Proteínas ras/genética , Animales , Astrocitos/citología , Astrocitos/fisiología , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/fisiopatología , Calgranulina A/metabolismo , Calgranulina B/metabolismo , Corteza Cerebral/citología , Regulación Neoplásica de la Expresión Génica/fisiología , Glioblastoma/genética , Glioblastoma/fisiopatología , Gliosis/fisiopatología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mitosis/fisiología , Células Mieloides/citología , Células Mieloides/fisiología , Neuronas/citología , Lesiones Precancerosas/genética , Lesiones Precancerosas/fisiopatología , Cultivo Primario de Células , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas p21(ras) , Receptor para Productos Finales de Glicación Avanzada , Receptores Inmunológicos/metabolismo , Transducción de Señal/fisiología , Receptor Toll-Like 4/metabolismo , Proteínas ras/metabolismo
11.
Stem Cells Transl Med ; 12(8): 553-568, 2023 08 16.
Artículo en Inglés | MEDLINE | ID: mdl-37399126

RESUMEN

Human embryonic stem cells-derived neural progenitor cells (hESCs-NPCs) transplantation holds great potential to treat stroke. We previously reported that delayed secondary degeneration occurs in the ventroposterior nucleus (VPN) of ipsilateral thalamus after distal branch of middle cerebral artery occlusion (dMCAO) in adult male Sprague-Dawley (SD) rats. In this study, we investigate whether hESCs-NPCs would benefit the neural recovery of the secondary damage in the VPN after focal cerebral infarction. Permanent dMCAO was performed with electrocoagulation. Rats were randomized into Sham, dMCAO groups with or without hESCs-NPCs treatment. HESCs-NPCs were engrafted into the peri-infarct regions of rats at 48 h after dMCAO. The transplanted hESCs-NPCs survive and partially differentiate into mature neurons after dMCAO. Notably, hESCs-NPCs transplantation attenuated secondary damage of ipsilateral VPN and improved neurological functions of rats after dMCAO. Moreover, hESCs-NPCs transplantation significantly enhanced the expression of BDNF and TrkB and their interaction in ipsilateral VPN after dMCAO, which was reversed by the knockdown of TrkB. Transplantated hESCs-NPCs reconstituted thalamocortical connection and promoted the formation of synapses in ipsilateral VPN post-dMCAO. These results suggest that hESCs-NPCs transplantation attenuates secondary damage of ipsilateral thalamus after cortical infarction, possibly through activating BDNF/TrkB pathway, enhancing thalamocortical projection, and promoting synaptic formation. It provides a promising therapeutic strategy for secondary degeneration in the ipsilateral thalamus post-dMCAO.


Asunto(s)
Células Madre Embrionarias , Infarto de la Arteria Cerebral Media , Células-Madre Neurales , Humanos , Células Madre Embrionarias/trasplante , Animales , Ratas , Ratas Sprague-Dawley , Infarto de la Arteria Cerebral Media/metabolismo , Infarto de la Arteria Cerebral Media/patología , Infarto de la Arteria Cerebral Media/terapia , Células-Madre Neurales/trasplante , Diferenciación Celular , Movimiento Celular , Transducción de Señal , Neuroprotección , Tálamo/metabolismo
12.
J Neuroimmunol ; 377: 578065, 2023 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-36931208

RESUMEN

Toll-like receptors (TLRs) are a class of proteins that play essential roles in innate and adaptive immune responses. Recently, accumulating evidence has demonstrated that impairments in the TLR signalling pathway contribute to the development and progression of neuroimmune diseases, such as neuromyelitis optica spectrum disorder (NMOSD). However, the cellular and molecular mechanisms are still largely unknown. In this study, we report a novel variant, C52Y, of canopy FGF signalling regulator 3 (CNPY3) from patients with familial NMOSD and demonstrate that this variant shows a stronger interaction with GP96 and TLRs than with wild-type CNPY3. We find that C52Y has dominant negative effects on TLR4 surface expression. Importantly, the TLR4 surface expression level is decreased in RAW264.7 cells infected with the C52Y virus upon LPS stimulation. We further demonstrate that bone marrow-derived macrophages (BMDMs) from CNPY3C52Y/+ transgenic mice secrete less tumour necrosis factor (TNF) and interleukin (IL)-6 than BMDMs from wild-type mice upon stimulation with LPS. These data suggest that impairment of TLR trafficking may contribute to the development of neuroimmune disorders.


Asunto(s)
Neuromielitis Óptica , Animales , Ratones , Inmunidad , Interleucina-6 , Lipopolisacáridos , Ratones Transgénicos , Neuromielitis Óptica/genética , Neuromielitis Óptica/metabolismo , Receptor Toll-Like 4/genética , Receptores Toll-Like/metabolismo
13.
J Cancer ; 14(11): 2085-2092, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37497418

RESUMEN

Background: Lymph node necrosis (LNN), including retropharyngeal nodal necrosis and cervical nodal necrosis, which is related to radiotherapy/ chemotherapy resistance, is a common phenomenon in nasopharyngeal carcinoma (NPC). This study was to assess the prognostic value of LNN at different N stages in NPC patients. Materials and Methods: In total, 1,665 newly diagnosed NPC patients at stage TxN1-3M0 from two centers were enrolled. Univariate and multivariate models were constructed to assess the association between LNN and long-term survival outcomes. The propensity score matching method was performed to balance treatment groups for baseline characteristics. Results: Of the 1,665, 540 patients (540/1665, 32.4%) were diagnosed with LNN, of which 54.1% (292/540) patients were at stage N1, 31.3% (169/540) at stage N2, and 14.6% (79/540) at stage N3. Univariate and multivariate analyses indicated LNN as an independent predictor for progression­free survival (PFS), overall survival (OS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) in stage N1-3 patients (all P<0.001). When patients were analyzed according to stage, similar findings were observed for N1 patients (all P<0.001); for N2 patients, LNN independently predicted PFS (P=0.003), OS (P=0.011), and DMFS (P=0.004), and for stage N3, LNN only independently predicted LRRFS (P=0.019). 123 pairs of patients who received induction chemotherapy plus concurrent chemoradiotherapy or only concurrent chemoradiotherapy were matched, adding induction chemotherapy improved 5-year OS, PFS and LRFFS, but the results were not statistically significant. Conclusions: In NPC patients, LNN could independently predict poor prognosis at all N1-3 stages and at each N stage (N1 to N3). The value of adding induction chemotherapy to concurrent chemoradiotherapy in patients with LNN still requires further prospective studies.

14.
Brain Res ; 1795: 148073, 2022 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-36075466

RESUMEN

More than 30 % of individuals with epilepsy are refractory to currently available drugs, highlighting the urgent need to develop novel candidate drugs. Accumulating evidence implicates the key role of ferroptosis in the pathophysiology of epileptic seizuresand its potential as a new drug target. Drug repurposing is a promising strategy for the rapid generation of new candidate drugs from the market drugs with new therapeutic indications, such as the best-selling drug thalidomide. Herein, we reported the discovery of Seratrodast, a market drug of thromboxane A2 receptor antagonist as a new ferroptosis inhibitor (IC50: 4.5 µmol·L-1). Seratrodast could reduce lipid ROS production, regulate the system xc-/glutathione (GSH)/glutathione peroxidase 4 (GPX4) axis, and inhibit JNK phosphorylation and p53 expression. In addition, Seratrodast elevated GPX4 expression and decreased JNK phosphorylation in pentylenetetrazole-induced seizures in mice. Seratrodast increased the latency of seizures and reduced seizure duration in pentylenetetrazole-induced seizures. Our results suggest Seratrodast might be either a ferroptosis inhibitor or a novel lead compound for further optimization of novel drug discovery.


Asunto(s)
Epilepsia , Ferroptosis , Ácidos Heptanoicos , Animales , Benzoquinonas , Glutatión/metabolismo , Ratones , Pentilenotetrazol , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Receptores de Tromboxano A2 y Prostaglandina H2/metabolismo , Convulsiones/tratamiento farmacológico , Talidomida , Proteína p53 Supresora de Tumor/metabolismo
15.
Stem Cell Reports ; 17(2): 276-288, 2022 02 08.
Artículo en Inglés | MEDLINE | ID: mdl-35030322

RESUMEN

Human neural progenitor cell (hNPC) transplantation holds great potential to treat neurological diseases. However, hNPC grafts take a long time to differentiate into mature neurons due to their intrinsically prolonged developmental timetable. Here, we report that postoperative physical exercise (PE), a prevailing rehabilitation intervention, promotes the neuronal commitment, maturation, and integration of engrafted hNPCs, evidenced by forming more synapses, receiving more synaptic input from host neurons, and showing higher neuronal activity levels. More important, NPC transplantation, combined with PE, shows significant improvement in both structural and behavioral outcomes in stroke-damaged rats. PE enhances ingrowth of blood vessels around the infarction region and neural tract reorganization along the ischemic boundary. The combination of NPC transplantation and postoperative PE creates both a neurotrophic/growth factor-enriched proneuronal microenvironment and an ideal condition for activity-dependent plasticity to give full play to its effects. Our study provides a potential approach to treating patients with stroke injury.


Asunto(s)
Células-Madre Neurales/trasplante , Condicionamiento Físico Animal , Accidente Cerebrovascular/terapia , Animales , Vasos Sanguíneos/fisiología , Microambiente Celular , Modelos Animales de Enfermedad , Humanos , Masculino , Factores de Crecimiento Nervioso/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Accidente Cerebrovascular/patología , Sinapsis/metabolismo , Transcriptoma
16.
BMC Ecol Evol ; 21(1): 71, 2021 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-33931026

RESUMEN

BACKGROUND: Cultivated tea is one of the most important economic and ecological trees distributed worldwide. Cultivated tea suffer from long-term targeted selection of traits and overexploitation of habitats by human beings, which may have changed its genetic structure. The chloroplast is an organelle with a conserved cyclic genomic structure, and it can help us better understand the evolutionary relationship of Camellia plants. RESULTS: We conducted comparative and evolutionary analyses on cultivated tea and wild tea, and we detected the evolutionary characteristics of cultivated tea. The chloroplast genome sizes of cultivated tea were slightly different, ranging from 157,025 to 157,100 bp. In addition, the cultivated species were more conserved than the wild species, in terms of the genome length, gene number, gene arrangement and GC content. However, comparing Camellia sinensis var. sinensis and Camellia sinensis var. assamica with their cultivars, the IR length variation was approximately 20 bp and 30 bp, respectively. The nucleotide diversity of 14 sequences in cultivated tea was higher than that in wild tea. Detailed analysis on the genomic variation and evolution of Camellia sinensis var. sinensis cultivars revealed 67 single nucleotide polymorphisms (SNPs), 46 insertions/deletions (indels), and 16 protein coding genes with nucleotide substitutions, while Camellia sinensis var. assamica cultivars revealed 4 indels. In cultivated tea, the most variable gene was ycf1. The largest number of nucleotide substitutions, five amino acids exhibited site-specific selection, and a 9 bp sequence insertion were found in the Camellia sinensis var. sinensis cultivars. In addition, phylogenetic relationship in the ycf1 tree suggested that the ycf1 gene has diverged in cultivated tea. Because C. sinensis var. sinensis and its cultivated species were not tightly clustered. CONCLUSIONS: The cultivated species were more conserved than the wild species in terms of architecture and linear sequence order. The variation of the chloroplast genome in cultivated tea was mainly manifested in the nucleotide polymorphisms and sequence insertions. These results provided evidence regarding the influence of human activities on tea.


Asunto(s)
Camellia sinensis , Camellia , Genoma del Cloroplasto , Camellia/genética , Camellia sinensis/genética , Genoma del Cloroplasto/genética , Humanos , Filogenia ,
17.
Cell Regen ; 10(1): 30, 2021 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-34487238

RESUMEN

Polycomb repressive complexes (PRCs) are essential in mouse gastrulation and specify neural ectoderm in human embryonic stem cells (hESCs), but the underlying molecular basis remains unclear. Here in this study, by employing an array of different approaches, such as gene knock-out, RNA-seq, ChIP-seq, et al., we uncover that EZH2, an important PRC factor, specifies the normal neural fate decision through repressing the competing meso/endoderm program. EZH2-/- hESCs show an aberrant re-activation of meso/endoderm genes during neural induction. At the molecular level, EZH2 represses meso/endoderm genes while SOX2 activates the neural genes to coordinately specify the normal neural fate. Moreover, EZH2 also supports the proliferation of human neural progenitor cells (NPCs) through repressing the aberrant expression of meso/endoderm program during culture. Together, our findings uncover the coordination of epigenetic regulators such as EZH2 and lineage factors like SOX2 in normal neural fate decision.

18.
Stem Cell Res Ther ; 12(1): 376, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34215315

RESUMEN

BACKGROUND: There is a huge controversy about whether xenograft or allograft in the "immune-privileged" brain needs immunosuppression. In animal studies, the prevailing sophisticated use of immunosuppression or immunodeficient animal is detrimental for the recipients, which results in a short lifespan of animals, confounds functional behavioral readout of the graft benefits, and discourages long-term follow-up. METHODS: Neuron-restricted neural progenitor cells (NPCs) were derived from human embryonic stem cells (ESCs, including H1, its gene-modified cell lines for better visualization, and HN4), propagated for different passages, and then transplanted into the brain of immunocompetent rats without immunosuppressants. The graft survivals, their cell fates, and HLA expression levels were examined over time (up to 4 months after transplantation). We compared the survival capability of NPCs from different passages and in different transplantation sites (intra-parenchyma vs. para- and intra-cerebroventricle). The host responses to the grafts were also investigated. RESULTS: Our results show that human ESC-derived neuron-restricted NPCs survive extendedly in adult rat brain parenchyma with no need of immunosuppression whereas a late-onset graft rejection seems inevitable. Both donor HLA antigens and host MHC-II expression level remain relatively low with little change over time and cannot predict the late-onset rejection. The intra-/para-cerebroventricular human grafts are more vulnerable to the immune attack than the intrastriatal counterparts. Prevention of graft hyperplasia by using hypoproliferative late passaged human NPCs further significantly extends the graft survival time. Our new data also shows that a subpopulation of host microglia upregulate MHC-II expression in response to the human graft, but fail to present the human antigen to the host immune system, suggestive of the immune-isolation role of the blood-brain barrier (BBB). CONCLUSIONS: The present study confirms the "immune privilege" of the brain parenchyma and, more importantly, unveils that choosing hypoproliferative NPCs for transplantation can benefit graft outcome in terms of both lower tumor-genic risk and the prolonged survival time without immunosuppression.


Asunto(s)
Trasplante de Tejido Encefálico , Células-Madre Neurales , Animales , Encéfalo , Rechazo de Injerto , Supervivencia de Injerto , Xenoinjertos , Humanos , Ratas , Ratas Sprague-Dawley
19.
Stem Cell Res ; 43: 101693, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31978714

RESUMEN

Death-associated protein kinase 1 (DAPK1) is a Ca2+/calmodulin regulated Ser/Thr kinase involved in various cellular processes including cell death, autophagy and inflammation. Its dysregulation has been linked to tumour metastasis, anti-viral responses, Alzheimer's disease and other neurological disorders. To further investigate the role of DAPK1 in these processes, we generated a DAPK1 knockout first (conditional ready) human embryonic stem (hES) cell line in which the endogenous DAPK1 can be easily restored with expression of FLPe. This cell line provides an ideal model to study the role of DAPK1 in human development and various pathologies related to DAPK1 dysregulation in vitro.


Asunto(s)
Sistemas CRISPR-Cas/genética , Proteínas Quinasas Asociadas a Muerte Celular/genética , Células Madre Embrionarias Humanas/metabolismo , Línea Celular , Humanos , Masculino
20.
J Clin Neurol ; 16(3): 470-479, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32657069

RESUMEN

BACKGROUND AND PURPOSE: Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe central nervous system disorder mediated by NMDAR antibodies that damages neurons. We investigated the correlation between cytoskeletal autoantibodies and the clinical severity in patients with anti-NMDAR encephalitis. METHODS: Non-NMDAR autoantibodies were identified by screening matched cerebrospinal fluid (CSF) and the serum samples of 45 consecutive patients with anti-NMDAR encephalitis and 60 healthy individuals against N-methyl-D-aspartate receptor 1-transfected and nontransfected human embryonic kidney 293T cells. Immunocytochemistry was performed to assess antibody binding in rat brain sections and primary cortical neurons. Cell-based assays and Western blotting were applied to identify autoantibodies targeting medium neurofilaments (NFMs). We compared clinical characteristics between patients with NMDAR encephalitis who were positive and negative for anti-NFM-autoantibodies. RESULTS: Anti-NFM autoantibodies were detected in both the serum and CSF in one patient (2%) and in the serum only in six patients (13%). No antibodies were detected in the serum of healthy controls (7/45 vs. 0/60, p=0.0016). Four of the seven patients with anti-NFM autoantibodies in serum were children (57%), and three (43%) had abnormalities in brain magnetic resonance imaging. These patients responded well to immunotherapy, and either no significant or only mild disability was observed at the last follow-up. Anti-NMDAR encephalitis did not differ with the presence of anti-NFM autoantibodies. CONCLUSIONS: Anti-NFM autoantibodies may be present in patients with anti-NMDAR encephalitis, indicating underlying neuronal damage. A large cohort study is warranted to investigate the clinical differences between patients with NMDAR encephalitis according to their anti-NFM antibody status.

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