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1.
Mol Cell ; 52(1): 101-12, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-24055342

RESUMO

Abundantly expressed in fetal tissues and adult muscle, the developmentally regulated H19 long noncoding RNA (lncRNA) has been implicated in human genetic disorders and cancer. However, how H19 acts to regulate gene function has remained enigmatic, despite the recent implication of its encoded miR-675 in limiting placental growth. We noted that vertebrate H19 harbors both canonical and noncanonical binding sites for the let-7 family of microRNAs, which plays important roles in development, cancer, and metabolism. Using H19 knockdown and overexpression, combined with in vivo crosslinking and genome-wide transcriptome analysis, we demonstrate that H19 modulates let-7 availability by acting as a molecular sponge. The physiological significance of this interaction is highlighted in cultures in which H19 depletion causes precocious muscle differentiation, a phenotype recapitulated by let-7 overexpression. Our results reveal an unexpected mode of action of H19 and identify this lncRNA as an important regulator of the major let-7 family of microRNAs.


Assuntos
Impressão Genômica , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Sítios de Ligação , Diferenciação Celular , Biologia Computacional , Bases de Dados Genéticas , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica , Genótipo , Células HEK293 , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Camundongos , MicroRNAs/genética , Desenvolvimento Muscular , Mioblastos Esqueléticos/metabolismo , Fenótipo , Interferência de RNA , RNA Longo não Codificante/genética , Ribonucleoproteínas/metabolismo , Fatores de Tempo , Transfecção
2.
Eur J Clin Invest ; 49(4): e13078, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30725490

RESUMO

BACKGROUND: Previous studies revealed that patients with Takotsubo syndrome (TTS) have a higher mortality rate than the general population and a comparable mortality to acute coronary syndrome (ACS). Repolarisation abnormalities, namely T-wave amplitude, may provide incremental prognostic information, in addition to traditional risk factors in ACS. This study was performed to determine the short- and long-term prognostic impact of inverted T-waves in TTS patients, as compared to ACS patients. METHODS AND RESULTS: Our institutional database constituted a collective of 138 patients diagnosed with TTS from 2003 to 2017, as well as 532 patients suffering from ACS. Patients with TTS or with ACS (n = 138 per group) were matched for age and sex and assessed retrospectively and prospectively and divided into two groups, TTS with inverted T-waves (n = 123) and ACS with inverted T-waves (n = 80). In-hospital complications such as respiratory failure with the need of respiratory support (60.2% vs 6.3%; P < 0.01), thromboembolic events (13.8% vs 2.5%; P < 0.01) and cardiogenic shock (18.9% vs 8.8%; P = 0.05) were significantly more presented in TTS as compared to ACS patients. Among cardiovascular risk factors diabetes mellitus (23.6% vs 45.0%; P < 0.01) and arterial hypertension (57.7% vs 78.8%; P < 0.01) were more presented in ACS patients as compared to TTS patients. Short-term mortality was similar, however the long-term mortality of 5 years was significantly higher in the TTS group (25.2% vs 7.5%; P < 0.01). In univariate analysis were male gender, EF < 35%, GFR < 60 mL/min, cardiogenic shock, inotropic drugs and history of cancer predictors of 5-year mortality. The multivariate analysis showed only male gender (HR 2.7, 95% CI 1.1-6.5; P = 0.02), GFR < 60 mL/min (HR 2.8, 95% CI 1.2-6.0; P = 0.01) and history of cancer (HR 3.6, 95% CI 1.4-9.3; P < 0.01) as independent predictors of 5-year mortality. CONCLUSION: Rates of long-term mortality were significantly higher in TTS patients showing inverted T-waves compared with patients diagnosed with ACS with inverted T-waves. However, T-inversion was not an independent predictor of 5-year mortality in the multivariate analysis.


Assuntos
Síndrome Coronariana Aguda/mortalidade , Arritmias Cardíacas/mortalidade , Cardiomiopatia de Takotsubo/mortalidade , Síndrome Coronariana Aguda/complicações , Idoso , Arritmias Cardíacas/complicações , Eletrocardiografia , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Masculino , Prognóstico , Estudos Retrospectivos , Cardiomiopatia de Takotsubo/complicações , Tromboembolia/etiologia , Tromboembolia/mortalidade
3.
Europace ; 20(FI1): f46-f56, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29566126

RESUMO

Aims: Our aim is to investigate the arrhythmogenic mechanism in arrhythmogenic right ventricular cardiomyopathy (ARVC)-patients by using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Methods and results: Human-induced pluripotent stem cell-derived cardiomyocytes were generated from human skin fibroblasts of two healthy donors and an ARVC-patient with a desmoglein-2 (DSG2) mutation. Patch clamp, quantitative polymerase chain reaction, and calcium imaging techniques were employed for the study. The amplitude and maximal upstroke velocity (Vmax) of action potential (AP) in ARVC-cells were smaller than that in healthy donor cells, whereas the resting potential and AP duration (APD) was not changed. The reduced Vmax resulted from decreased peak sodium current. The reason for undetected changes in APD may be the counter-action of reduced transient outward, small conductance Ca2+-activated, adenosine triphosphate-sensitive, Na/Ca exchanger (INCX) currents, and enhanced rapidly delayed rectifier currents. Isoprenaline (Iso) reduced INCX and shortened APD in both donor and ARVC-hiPSC-CMs. However, the effects of Iso in ARVC-cells are significantly larger than that in donor cells. In addition, ARVC-hiPSC-CMs showed more frequently than donor cells arrhythmogenic events induced by adrenergic stimulation. Conclusion: Cardiomyocytes derived from the ARVC patient with a DSG2 mutation displayed multiple ion channel dysfunctions and abnormal cellular electrophysiology as well as enhanced sensitivity to adrenergic stimulation. These may underlie the arrhythmogenesis in ARVC patients.


Assuntos
Potenciais de Ação , Displasia Arritmogênica Ventricular Direita/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Potenciais de Ação/efeitos dos fármacos , Agonistas Adrenérgicos beta/farmacologia , Displasia Arritmogênica Ventricular Direita/genética , Displasia Arritmogênica Ventricular Direita/patologia , Displasia Arritmogênica Ventricular Direita/fisiopatologia , Sinalização do Cálcio , Estudos de Casos e Controles , Células Cultivadas , Canais de Potássio de Retificação Tardia/metabolismo , Desmogleína 2/genética , Desmogleína 2/metabolismo , Predisposição Genética para Doença , Frequência Cardíaca , Humanos , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/patologia , Isoproterenol/farmacologia , Cinética , Masculino , Pessoa de Meia-Idade , Mutação , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Fenótipo , Trocador de Sódio e Cálcio/metabolismo
4.
J Ultrasound Med ; 37(6): 1293-1303, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29171066

RESUMO

Vitamin D deficiency is associated with an increased risk of subclinical atherosclerosis. To explore the potential link of the serum vitamin D level with carotid atherosclerosis, this meta-analysis assessed the correlation between vitamin D and carotid intima-media thickness as well as carotid atherosclerotic plaque. PubMed, Embase, Web of Science, and Cochrane Library databases were searched until the end of March 2017. Clinical studies investigating the relationship between vitamin D and carotid atherosclerosis were included. The outcome data were extracted according to the inclusion criteria and pooled for an effect estimate by a random-effects model. Of the 506 initially retrieved studies, 11 studies involving a total of 16,434 participants were included in the meta-analysis. Newcastle-Ottawa Quality Assessment Scale scores suggested that the included studies were of high quality. The pooled effects estimate showed that the serum vitamin D level was negatively associated with carotid atherosclerosis (odds ratio, 0.95; 95% confidence interval [CI], 0.93-0.96), with substantial heterogeneity among the individual studies (I2 = 54%). Furthermore, a subgroup analysis suggested that hypovitaminosis D was associated with an 0.85-fold decrease in the odds of having a higher carotid intima-media thickness (95% CI, 0.76-0.96; P < .05; I2 = 69%). Additionally, the pooled analysis also indicated that the serum vitamin D level was a protective factor against increased carotid plaque (odds ratio, 0.95; 95% CI, 0.93-0.97; P < .05; I2 = 29%). Funnel plots and the Egger regression test showed the absence of a publication bias. In this meta-analysis, we comprehensively revealed a close link between vitamin D deficiency and carotid atherosclerosis. Patients with hypovitaminosis D might have extra requirements for preventive and therapeutic measures against early atherosclerosis, thus reducing the cardiovascular disease risk in the long term.


Assuntos
Aterosclerose/sangue , Doenças das Artérias Carótidas/sangue , Deficiência de Vitamina D/sangue , Vitamina D/sangue , Aterosclerose/complicações , Biomarcadores/sangue , Artérias Carótidas , Doenças das Artérias Carótidas/complicações , Espessura Intima-Media Carotídea , Humanos , Placa Aterosclerótica/sangue , Placa Aterosclerótica/complicações , Fatores de Risco , Deficiência de Vitamina D/complicações
5.
Eur Heart J ; 38(22): 1764-1774, 2017 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-28057773

RESUMO

AIMS: Atrial fibrillation (AF) prevalence increases with advanced stages of left ventricular (LV) dysfunction. Remote proarrhythmic effects of ventricular dysfunction on atrial electrophysiology remain incompletely understood. We hypothesized that repolarizing K2P3.1 K+ channels, previously implicated in AF pathophysiology, may contribute to shaping the atrial action potential (AP), forming a specific electrical substrate with LV dysfunction that might represent a target for personalized antiarrhythmic therapy. METHODS AND RESULTS: A total of 175 patients exhibiting different stages of LV dysfunction were included. Ion channel expression was quantified by real-time polymerase chain reaction and Western blot. Membrane currents and APs were recorded from atrial cardiomyocytes using the patch-clamp technique. Severely reduced LV function was associated with decreased atrial K2P3.1 expression in sinus rhythm patients. In contrast, chronic (c)AF resulted in increased K2P3.1 levels, but paroxysmal (p)AF was not linked to significant K2P3.1 remodelling. LV dysfunction-related suppression of K2P3.1 currents prolonged atrial AP duration (APD) compared with patients with preserved LV function. In individuals with concomitant LV dysfunction and cAF, APD was determined by LV dysfunction-associated prolongation and by cAF-dependent shortening, respectively, consistent with changes in K2P3.1 abundance. K2P3.1 inhibition attenuated APD shortening in cAF patients irrespective of LV function, whereas in pAF subjects with severely reduced LV function, K2P3.1 blockade resulted in disproportionately high APD prolongation. CONCLUSION: LV dysfunction is associated with reduction of atrial K2P3.1 channel expression, while cAF leads to increased K2P3.1 abundance. Differential remodelling of K2P3.1 and APD provides a basis for patient-tailored antiarrhythmic strategies.


Assuntos
Potenciais de Ação/fisiologia , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/fisiopatologia , Proteínas do Tecido Nervoso/metabolismo , Canais de Potássio de Domínios Poros em Tandem/metabolismo , Disfunção Ventricular Esquerda/fisiopatologia , Idoso , Fibrilação Atrial/tratamento farmacológico , Índice de Massa Corporal , Doença do Sistema de Condução Cardíaco/etiologia , Doença do Sistema de Condução Cardíaco/fisiopatologia , Cardiomiopatia Dilatada/fisiopatologia , Regulação para Baixo/fisiologia , Feminino , Humanos , Masculino , Proteínas do Tecido Nervoso/antagonistas & inibidores , Canais de Potássio de Domínios Poros em Tandem/antagonistas & inibidores , Distribuição por Sexo , Fumar/efeitos adversos , Fumar/fisiopatologia , Regulação para Cima/fisiologia , Remodelação Ventricular/fisiologia
6.
Neuro Endocrinol Lett ; 38(2): 124-128, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28650606

RESUMO

BACKGROUND: Previous studies have shown that heroin abuse can alter the gonadal functions. Few studies examined the association between testosterone levels and heroin use in the existing literature. We aimed to determine the association between gonadal hormones and heroin usage characteristics over 12 weeks of abstinence in heroin users. METHODS: We collected data on patient demographics and heroin use patterns for 65 men aged 18 to 45 and for 29 age-matched healthy controls. Serum levels of total testosterone, estradiol, and prolactin were assessed at 5 time points. RESULTS: Testosterone levels gradually increased and prolactin levels decreased in heroin users in this study. In heroin users, a significant positive correlation was observed between the way of using drug and the testosterone levels, the way of using drug and the estradiol levels, between the duration of heroin dependence and the testosterone levels, between the duration of heroin dependence and the estradiol levels on D0, and between relapse time and testosterone levels on D84. CONCLUSIONS: Our data reveal testosterone might promote injection drug use and repeated relapse in male heroin users.


Assuntos
Dependência de Heroína/sangue , Heroína/administração & dosagem , Testosterona/sangue , Adolescente , Adulto , Estradiol/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Prolactina/sangue , Adulto Jovem
9.
Circulation ; 132(2): 82-92, 2015 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-25951834

RESUMO

BACKGROUND: Antiarrhythmic management of atrial fibrillation (AF) remains a major clinical challenge. Mechanism-based approaches to AF therapy are sought to increase effectiveness and to provide individualized patient care. K(2P)3.1 (TASK-1 [tandem of P domains in a weak inward-rectifying K+ channel-related acid-sensitive K+ channel-1]) 2-pore-domain K+ (K(2P)) channels have been implicated in action potential regulation in animal models. However, their role in the pathophysiology and treatment of paroxysmal and chronic patients with AF is unknown. METHODS AND RESULTS: Right and left atrial tissue was obtained from patients with paroxysmal or chronic AF and from control subjects in sinus rhythm. Ion channel expression was analyzed by quantitative real-time polymerase chain reaction and Western blot. Membrane currents and action potentials were recorded using voltage- and current-clamp techniques. K(2P)3.1 subunits exhibited predominantly atrial expression, and atrial K(2P)3.1 transcript levels were highest among functional K(2P) channels. K(2P)3.1 mRNA and protein levels were increased in chronic AF. Enhancement of corresponding currents in the right atrium resulted in shortened action potential duration at 90% of repolarization (APD90) compared with patients in sinus rhythm. In contrast, K(2P)3.1 expression was not significantly affected in subjects with paroxysmal AF. Pharmacological K(2P)3.1 inhibition prolonged APD90 in atrial myocytes from patients with chronic AF to values observed among control subjects in sinus rhythm. CONCLUSIONS: Enhancement of atrium-selective K(2P)3.1 currents contributes to APD shortening in patients with chronic AF, and K(2P)3.1 channel inhibition reverses AF-related APD shortening. These results highlight the potential of K(2P)3.1 as a novel drug target for mechanism-based AF therapy.


Assuntos
Potenciais de Ação/fisiologia , Fibrilação Atrial/metabolismo , Fibrilação Atrial/fisiopatologia , Canais de Potássio de Domínios Poros em Tandem/biossíntese , Regulação para Cima/fisiologia , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/diagnóstico , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso
10.
Arterioscler Thromb Vasc Biol ; 35(8): 1852-61, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26088577

RESUMO

OBJECTIVE: Vascular smooth muscle cells (VSMC) proliferation is a hallmark of atherosclerosis and vascular restenosis. The intermediate conductance Ca(2+)-activated K(+) (SK4) channel is required for pathological VSMC proliferation. In T lymphocytes, nucleoside diphosphate kinase B (NDPKB) has been implicated in SK4 channel activation. We thus investigated the role of NDPKB in the regulation of SK4 currents (ISK4) in proliferating VSMC and neointima formation. APPROACH AND RESULTS: Function and expression of SK4 channels in VSMC from injured mouse carotid arteries were assessed by patch-clamping and real-time polymerase chain reaction. ISK4 was detectable in VSMC from injured but not from uninjured arteries correlating with the occurrence of the proliferative phenotype. Direct application of NDPKB to the membrane of inside-out patches increased ISK4, whereas NDPKB did not alter currents in VSMC obtained from injured vessels of SK4-deficient mice. The NDPKB-induced increase in ISK4 was prevented by protein histidine phosphatase 1, but not an inactive protein histidine phosphatase 1 mutant indicating that ISK4 is regulated via histidine phosphorylation in proliferating VSMC; moreover, genetic NDPKB ablation reduced ISK4 by 50% suggesting a constitutive activation of ISK4 in proliferating VSMC. In line, neointima formation after wire injury of the carotid artery was substantially reduced in mice deficient in SK4 channels or NDPKB. CONCLUSIONS: NDPKB to SK4 signaling is required for neointima formation. Constitutive activation of SK4 by NDPKB in proliferating VSMC suggests that targeting this interaction via, for example, activation of protein histidine phosphatase 1 may provide clinically meaningful effects in vasculoproliferative diseases such as atherosclerosis and post angioplasty restenosis.


Assuntos
Lesões das Artérias Carótidas/enzimologia , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/metabolismo , Músculo Liso Vascular/enzimologia , Miócitos de Músculo Liso/enzimologia , Nucleosídeo NM23 Difosfato Quinases/metabolismo , Neointima , Animais , Artérias Carótidas/enzimologia , Artérias Carótidas/patologia , Lesões das Artérias Carótidas/genética , Lesões das Artérias Carótidas/patologia , Proliferação de Células , Células Cultivadas , Modelos Animais de Doenças , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/deficiência , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Potenciais da Membrana , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Nucleosídeo NM23 Difosfato Quinases/deficiência , Nucleosídeo NM23 Difosfato Quinases/genética , Transdução de Sinais
11.
Nucleic Acids Res ; 42(22): 13799-811, 2014 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-25399420

RESUMO

The H19 lncRNA has been implicated in development and growth control and is associated with human genetic disorders and cancer. Acting as a molecular sponge, H19 inhibits microRNA (miRNA) let-7. Here we report that H19 is significantly decreased in muscle of human subjects with type-2 diabetes and insulin resistant rodents. This decrease leads to increased bioavailability of let-7, causing diminished expression of let-7 targets, which is recapitulated in vitro where H19 depletion results in impaired insulin signaling and decreased glucose uptake. Furthermore, acute hyperinsulinemia downregulates H19, a phenomenon that occurs through PI3K/AKT-dependent phosphorylation of the miRNA processing factor KSRP, which promotes biogenesis of let-7 and its mediated H19 destabilization. Our results reveal a previously undescribed double-negative feedback loop between sponge lncRNA and target miRNA that contributes to glucose regulation in muscle cells.


Assuntos
Glucose/metabolismo , MicroRNAs/metabolismo , Músculo Esquelético/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Regulação para Baixo , Retroalimentação Fisiológica , Humanos , Hiperinsulinismo/genética , Hiperinsulinismo/metabolismo , Insulina/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo , Proteínas de Ligação a RNA/fisiologia , Transdução de Sinais , Transativadores/fisiologia
12.
Circulation ; 129(4): 430-40, 2014 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-24190961

RESUMO

BACKGROUND: Recent evidence points to functional Ca²âº-dependent K⁺ (SK) channels in the heart that may govern atrial fibrillation (AF) risk, but the underlying mechanisms are unclear. This study addressed the role of SK channels in atrial repolarization and AF persistence in a canine AF model. METHODS AND RESULTS: Electrophysiological variables were assessed in dogs subjected to atrial remodeling by 7-day atrial tachypacing (AT-P), as well as controls. Ionic currents and single-channel properties were measured in isolated canine atrial cardiomyocytes by patch clamp. NS8593, a putative selective SK blocker, suppressed SK current with an IC50 of ≈5 µmol/L, without affecting Na⁺, Ca²âº, or other K⁺ currents. Whole-cell SK current sensitive to NS8593 was significantly larger in pulmonary vein (PV) versus left atrial (LA) cells, without a difference in SK single-channel open probability (P(o)), whereas AT-P enhanced both whole-cell SK currents and single-channel P(o). SK-current block increased action potential duration in both PV and LA cells after AT-P; but only in PV cells in absence of AT-P. SK2 expression was more abundant at both mRNA and protein levels for PV versus LA in control dogs, in both control and AT-P; AT-P upregulated only SK1 at the protein level. Intravenous administration of NS8593 (5 mg/kg) significantly prolonged atrial refractoriness and reduced AF duration without affecting the Wenckebach cycle length, left ventricular refractoriness, or blood pressure. CONCLUSIONS: SK currents play a role in canine atrial repolarization, are larger in PVs than LA, are enhanced by atrial-tachycardia remodeling, and appear to participate in promoting AF maintenance. These results are relevant to the potential mechanisms underlying the association between SK single-nucleotide polymorphisms and AF and suggest SK blockers as potentially interesting anti-AF drugs.


Assuntos
Fibrilação Atrial/patologia , Fibrilação Atrial/fisiopatologia , Fenômenos Eletrofisiológicos/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/fisiologia , 1-Naftilamina/análogos & derivados , 1-Naftilamina/farmacologia , Animais , Modelos Animais de Doenças , Cães , Técnicas Eletrofisiológicas Cardíacas , Átrios do Coração/efeitos dos fármacos , Átrios do Coração/patologia , Miócitos Cardíacos/patologia , Miócitos Cardíacos/fisiologia , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/farmacologia , Veias Pulmonares/efeitos dos fármacos , Veias Pulmonares/patologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/efeitos dos fármacos
13.
Basic Res Cardiol ; 110(5): 505, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26162324

RESUMO

Voltage-gated Kv1.1 channels encoded by the Kcna1 gene are traditionally regarded as being neural-specific with no known expression or intrinsic functional role in the heart. However, recent studies in mice reveal low-level Kv1.1 expression in heart and cardiac abnormalities associated with Kv1.1-deficiency suggesting that the channel may have a previously unrecognized cardiac role. Therefore, this study tests the hypothesis that Kv1.1 channels are associated with arrhythmogenesis and contribute to intrinsic cardiac function. In intra-atrial burst pacing experiments, Kcna1-null mice exhibited increased susceptibility to atrial fibrillation (AF). The atria of Kcna1-null mice showed minimal Kv1 family ion channel remodeling and fibrosis as measured by qRT-PCR and Masson's trichrome histology, respectively. Using RT-PCR, immunocytochemistry, and immunoblotting, KCNA1 mRNA and protein were detected in isolated mouse cardiomyocytes and human atria for the first time. Patients with chronic AF (cAF) showed no changes in KCNA1 mRNA levels relative to controls; however, they exhibited increases in atrial Kv1.1 protein levels, not seen in paroxysmal AF patients. Patch-clamp recordings of isolated human atrial myocytes revealed significant dendrotoxin-K (DTX-K)-sensitive outward current components that were significantly increased in cAF patients, reflecting a contribution by Kv1.1 channels. The concomitant increases in Kv1.1 protein and DTX-K-sensitive currents in atria of cAF patients suggest that the channel contributes to the pathological mechanisms of persistent AF. These findings provide evidence of an intrinsic cardiac role of Kv1.1 channels and indicate that they may contribute to atrial repolarization and AF susceptibility.


Assuntos
Fibrilação Atrial/metabolismo , Átrios do Coração/metabolismo , Canal de Potássio Kv1.1/metabolismo , Idoso , Animais , Feminino , Humanos , Immunoblotting , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pessoa de Meia-Idade , Miócitos Cardíacos/metabolismo , Técnicas de Patch-Clamp , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
14.
Ear Nose Throat J ; : 1455613241275341, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39302102

RESUMO

Objectives: Vocal cord leukoplakia is clinically described as a white plaque or patch on the vocal cords observed during macroscopic examination, which does not take into account histological features or prognosis. A clinical challenge in managing vocal cord leukoplakia is to assess the potential malignant transformation of the lesion. This study aims to investigate the potential of deep learning (DL) for the simultaneous segmentation and classification of vocal cord leukoplakia using narrow band imaging (NBI) and white light imaging (WLI). The primary objective is to assess the model's accuracy in detecting and classifying lesions, comparing its performance in WLI and NBI. Methods: We applied DL to segment and classify NBI and WLI of vocal cord leukoplakia, and used pathological diagnosis as the gold standard. Results: The DL model autonomously detected lesions with an average intersection-over-union (IoU) >70%. In classification tasks, the model differentiated between lesions in the surgical group with a sensitivity of 93% and a specificity of 94% for WLI, and a sensitivity of 99% and a specificity of 97% for NBI. In addition, the model achieved a mean average precision of 81% in WLI and 92% in NBI, with an IoU threshold >0.5. Conclusions: The model proposed by us is helpful in assisting in accurate diagnosis of vocal cord leukoplakia from NBI and WLI.

15.
J Nutr Biochem ; 133: 109708, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-39059479

RESUMO

Gut flora is considered to modulate lipid transport from the intestine into the bloodstream, and thus may potentially participate in the development of GDM. Although previous studies have shown that the intestinal microbiota influences lipid transport and metabolism in GDM, the precise mechanisms remain elusive. To address this, we used a high-fat diet (HFD)-induced GDM mouse model and conducted 16s rRNA sequencing and fecal metabolomics to assess gut microbial community shifts and associated metabolite changes. Western blot, ELISA, and chromatin immunoprecipitation (ChIP) were utilized to elucidate how gut microbiota affect intestinal lipid transport and the insulin sensitivity of hepatic, adipose, and skeletal muscle tissues. We found that HFD impaired the oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) in pregnant mice. 16s rRNA sequencing demonstrated profound compositional changes, especially in the relative abundances of Firmicutes and Bacteroidetes. Metabolomics analysis presented a decline in the concentration of short-chain fatty acids (SCFAs) in the GDM group. Western blot analyses showed an upregulation of HDAC3 and a concurrent reduction in H3K27 acetylation in the intestine. ChIP-qPCR showed that PPAR-γ was inhibited, which in turn activated lipid-transporter CD36. ELISA and insulin signaling pathway detection in insulin-target organs showed high concentrations of circulating fatty acids and triglycerides and insulin resistance in insulin-target organs. Our results suggest that gut microbiota is closely associated with the development of GDM, partly because decreased gut flora-associated SCFAs activate CD36 by suppressing the HDAC3-H3K27ac-PPAR-γ axis to transport excessive fatty acids and triglycerides into blood circulation, thereby dysregulating the insulin sensitivity of insulin target organs.


Assuntos
Diabetes Gestacional , Dieta Hiperlipídica , Ácidos Graxos Voláteis , Microbioma Gastrointestinal , Histona Desacetilases , Metabolismo dos Lipídeos , Camundongos Endogâmicos C57BL , PPAR gama , Animais , Feminino , Gravidez , Diabetes Gestacional/metabolismo , Histona Desacetilases/metabolismo , Ácidos Graxos Voláteis/metabolismo , PPAR gama/metabolismo , Camundongos , Dieta Hiperlipídica/efeitos adversos , Histonas/metabolismo , Resistência à Insulina
16.
J Biol Chem ; 287(25): 20922-30, 2012 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-22547061

RESUMO

The Nrf2 (nuclear erythroid 2 p45-related factor-2) signaling pathway is known to play a pivotal role in a variety of oxidative stress-related human disorders. It has been reported recently that the plasma membrane resident protein caveolin-1 (Cav-1) can regulate expression of certain antioxidant enzymes and involves in the pathogenesis of oxidative lung injury, but the detailed molecular mechanisms remain incompletely understood. Here, we demonstrated that Cav-1 inhibited the expression of antioxidant enzymes through direct interaction with Nrf2 and subsequent suppression of its transcriptional activity in lung epithelial Beas-2B cells. Cav-1 deficiency cells exhibited higher levels of antioxidant enzymes and were more resistant to oxidative stress induced cytotoxicity, whereas overexpression of Cav-1 suppressed the induction of these enzymes and further augmented the oxidative cell death. Cav-1 constitutively interacted with Nrf2 in both cytosol and nucleus. Stimulation of 4-hydroxynonenol increased the Cav-1-Nrf2 interaction in cytosol but disrupted their association in the nucleus. Knockdown of Cav-1 also disassociated the interaction between Nrf2 and its cytoplasmic inhibitor Keap1 (Kelch-like ECH-associated protein 1) and increased the Nrf2 transcription activity. Mutation of the resembling Cav-1 binding motif on Nrf2 effectively attenuated their interaction, which exhibited higher transcription activity and induced higher levels of antioxidant enzymes relative to the wild-type control. Altogether, these studies clearly demonstrate that Cav-1 inhibits cellular antioxidant capacity through direct interaction with Nrf2 and subsequent suppression of its activity, thereby implicating in certain oxidative stress-related human pathologies.


Assuntos
Antioxidantes/metabolismo , Caveolina 1/metabolismo , Regulação Enzimológica da Expressão Gênica/fisiologia , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Motivos de Aminoácidos , Animais , Caveolina 1/genética , Linhagem Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Citosol/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch , Camundongos , Camundongos Knockout , Mutação , Fator 2 Relacionado a NF-E2/genética , Estresse Oxidativo/fisiologia
17.
Proc Natl Acad Sci U S A ; 107(17): 8005-10, 2010 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-20385812

RESUMO

Large conductance voltage- and Ca(2+)-activated potassium channels (BK channels) are important feedback regulators in excitable cells and are potently regulated by protein kinases. The present study reveals a dual role of protein kinase C (PKC) on BK channel regulation. Phosphorylation of S(695) by PKC, located between the two regulators of K(+) conductance (RCK1/2) domains, inhibits BK channel open-state probability. This PKC-dependent inhibition depends on a preceding phosphorylation of S(1151) in the C terminus of the channel alpha-subunit. Phosphorylation of only one alpha-subunit at S(1151) and S(695) within the tetrameric pore is sufficient to inhibit BK channel activity. We further detected that protein phosphatase 1 is associated with the channel, constantly counteracting phosphorylation of S(695). PKC phosphorylation at S(1151) also influences stimulation of BK channel activity by protein kinase G (PKG) and protein kinase A (PKA). Though the S(1151)A mutant channel is activated by PKA only, the phosphorylation of S(1151) by PKC renders the channel responsive to activation by PKG but prevents activation by PKA. Phosphorylation of S(695) by PKC or introducing a phosphomimetic aspartate at this position (S(695)D) renders BK channels insensitive to the stimulatory effect of PKG or PKA. Therefore, our findings suggest a very dynamic regulation of the channel by the local PKC activity. It is shown that this complex regulation is not only effective in recombinant channels but also in native BK channels from tracheal smooth muscle.


Assuntos
Canais de Potássio Ativados por Cálcio de Condutância Alta/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteína Quinase C/metabolismo , Análise de Variância , Animais , Bovinos , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Eletrofisiologia , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Alta/genética , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese Sítio-Dirigida , Técnicas de Patch-Clamp , Fosforilação , Proteína Fosfatase 1/metabolismo , Traqueia/citologia
18.
World J Psychiatry ; 13(7): 435-443, 2023 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-37547739

RESUMO

BACKGROUND: Genetic factors play an important role in the pathogenesis of panic disorder (PD). However, the effect of genetic variants on PD remains controversial. AIM: To evaluate the associations between glutamate decarboxylase 1 (GAD1) gene polymorphisms and PD risk and assess the effect of GAD1 gene polymorphisms on the severity of clinical symptoms in PD. METHODS: We recruited 230 PD patients and 224 healthy controls in this study. All participants were assessed for anxiety and panic symptom severity using the Hamilton Anxiety Rating Scale (HAM-A) and Panic Disorder Severity Scale (PDSS). GAD1 gene polymorphisms (rs1978340 and rs3749034) were genotyped and assessed for allele frequencies. RESULTS: There were no significant differences between cases and controls in the genotype distributions or allele frequencies of GAD1 (rs1978340 and rs3749034). In addition, the effect of GAD1 (rs1978340 and rs3749034) on PD severity was not significant. However, regarding respiratory symptoms, patients with the GAD1 rs1978340 A/A genotype had significantly higher scores than those with the A/G or G/G genotype. CONCLUSION: Here, we showed that the A/A genotype of GAD1 rs1978340 was associated with increased severity of respiratory symptoms in patients with PD.

20.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 30(1): 206-210, 2022 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-35123628

RESUMO

OBJECTIVE: To investigate the incidence and types of thalassemia in Xiangxi Tujia and Miao Autonomous Prefecture. METHODS: Automatic capillary electrophoresis was used to screen the thalassemia phenotypes of 22 940 blood samples of pregnant women and puerperants collected in our hospital and some other medical institutions in the prefecture during 2017-2019, among which there were 3 356 cases of Tujia ethnicity, 2 821 cases of Miao ethnicity, and 2 233 cases of Han ethnicity included, whose ethnicity were indicated. The samples with positive result would undergo further genetic testing. RESULTS: There were 2 314 cases of suspicious thalassemia were screened from 22 940 cases by the electrophoresis, thus the positive rate was 10.1% (hematological phenotypes from some other institutions were not included). Specifically, there were 1 706 cases with HBA2 less than 2.5%, 255 cases with HBA2 ranged from 2.5% to 3.5%, which displayed abnormal hematology (MCV or/and MCH) or other abnormal bands, and 353 cases with HBA2>3.5%. There were 436 suspected positive patients in 2 314 suspicious samples received further thalassemia gene testing in our hospital, among them 48 cases were diagnosed with α-thalassemia, 85 cases with ß-thalassemia, and 2 cases as compound type. The positive diagnosis rate of α-thalassemia gene test was 11.0%, ß-thalassemia was 19.4%, and positive pregnant women was 31.0%. CONCLUSION: The positive rate of thalassemia screening in Xiangxi Autonomous Prefecture is roughly the same as that in other regions of Hunan. The positive predictive value of ß-thalassemia screening is as high as 86%. Compared with the missed screening data, it is recommended to use hematology (MCV, MCH) method combined with capillary hemoglobin electrophoresis for thalassemia screening.


Assuntos
Talassemia alfa , Talassemia beta , Etnicidade , Feminino , Testes Genéticos , Hemoglobina A2/análise , Humanos , Gravidez , Gestantes , Talassemia alfa/genética , Talassemia beta/genética
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