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Patients with Takotsubo syndrome displayed endothelial dysfunction, but underlying mechanisms have not been fully clarified. This study aimed to explore molecular signalling responsible for catecholamine excess induced endothelial dysfunction. Human cardiac microvascular endothelial cells were challenged by epinephrine to mimic catecholamine excess. Patch clamp, FACS, ELISA, PCR, and immunostaining were employed for the study. Epinephrine (Epi) enhanced small conductance calcium-activated potassium channel current (ISK1-3) through activating α1 adrenoceptor. Phenylephrine enhanced edothelin-1 (ET-1) and reactive oxygen species (ROS) production, and the effects involved contribution of ISK1-3. H2O2 enhanced ISK1-3 and ET-1 production. Enhancing ISK1-3 caused a hyperpolarization, which increases ROS and ET-1 production. BAPTA partially reduced phenylephrine-induced enhancement of ET-1 and ROS, suggesting that α1 receptor activation can enhance ROS/ET-1 generation in both calcium-dependent and calcium-independent ways. The study demonstrates that high concentration catecholamine can activate SK1-3 channels through α1 receptor-ROS signalling and increase ET-1 production, facilitating vasoconstriction.
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Agonistas de Receptores Adrenérgicos alfa 1 , Células Endoteliales , Epinefrina , Especies Reactivas de Oxígeno , Receptores Adrenérgicos alfa 1 , Transducción de Señal , Canales de Potasio de Pequeña Conductancia Activados por el Calcio , Vasoconstricción , Humanos , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Receptores Adrenérgicos alfa 1/genética , Especies Reactivas de Oxígeno/metabolismo , Células Endoteliales/metabolismo , Células Endoteliales/efectos de los fármacos , Células Endoteliales/patología , Agonistas de Receptores Adrenérgicos alfa 1/farmacología , Vasoconstricción/efectos de los fármacos , Células Cultivadas , Epinefrina/farmacología , Peróxido de Hidrógeno/metabolismo , Potenciales de la Membrana , Fenilefrina/farmacología , Estrés Oxidativo/efectos de los fármacos , Endotelio Vascular/metabolismo , Endotelio Vascular/efectos de los fármacos , Endotelio Vascular/fisiopatología , Canales de Potasio Éter-A-Go-GoRESUMEN
Endothelial dysfunction may contribute to pathogenesis of Takotsubo cardiomyopathy, but mechanism underlying endothelial dysfunction in the setting of catecholamine excess has not been clarified. The study reports that D1/D5 dopamine receptor signaling and small conductance calcium-activated potassium channels contribute to high concentration catecholamine induced endothelial cell dysfunction. For mimicking catecholamine excess, 100 µM epinephrine (Epi) was used to treat human cardiac microvascular endothelial cells. Patch clamp, FACS, ELISA, PCR, western blot and immunostaining analyses were performed in the study. Epi enhanced small conductance calcium-activated potassium channel current (ISK1-3) without influencing the channel expression and the effect was attenuated by D1/D5 receptor blocker. D1/D5 agonists mimicked the Epi effect, suggesting involvement of D1/D5 receptors in Epi effects. The enhancement of ISK1-3 caused by D1/D5 activation involved roles of PKA, ROS and NADPH oxidases. Activation of D1/D5 and SK1-3 channels caused a hyperpolarization, reduced NO production and increased ROS production. The NO reduction was membrane potential independent, while ROS production was increased by the hyperpolarization. ROS (H2O2) suppressed NO production. The study demonstrates that high concentration catecholamine can activate D1/D5 and SK1-3 channels through NADPH-ROS and PKA signaling and reduce NO production, which may facilitate vasoconstriction in the setting of catecholamine excess.
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Células Endoteliales , Epinefrina , Especies Reactivas de Oxígeno , Transducción de Señal , Humanos , Transducción de Señal/efectos de los fármacos , Células Endoteliales/metabolismo , Células Endoteliales/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Óxido Nítrico/metabolismo , Catecolaminas/metabolismo , Canales de Potasio de Pequeña Conductancia Activados por el Calcio/metabolismo , Endotelio Vascular/metabolismo , Endotelio Vascular/patología , Endotelio Vascular/efectos de los fármacos , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , NADPH Oxidasas/metabolismo , Receptores de Dopamina D5/metabolismo , Receptores de Dopamina D1/metabolismo , Receptores Dopaminérgicos/metabolismoRESUMEN
Reperfusion therapy is critical for saving heart muscle after myocardial infarction, but the process of restoring blood flow can itself exacerbate injury to the myocardium. This phenomenon is known as myocardial ischemia-reperfusion injury (MIRI), which includes oxidative stress, inflammation, and further cell death. microRNA-146a (miR-146a) is known to play a significant role in regulating the immune response and inflammation, and has been studied for its potential impact on the improvement of heart function after myocardial injury. However, the delivery of miR-146a to the heart in a specific and efficient manner remains a challenge as extracellular RNAs are unstable and rapidly degraded. Milk exosomes (MEs) have been proposed as ideal delivery platform for miRNA-based therapy as they can protect miRNAs from RNase degradation. In this study, the effects of miR-146a containing MEs (MEs-miR-146a) on improvement of cardiac function were examined in a rat model of MIRI. To enhance the targeting delivery of MEs-miR-146a to the site of myocardial injury, the ischemic myocardium-targeted peptide IMTP was modified onto the surfaces, and whether the modified MEs-miR-146a could exert a better therapeutic role was examined by echocardiography, myocardial injury indicators and the levels of inflammatory factors. Furthermore, the expressions of miR-146a mediated NF-κB signaling pathway-related proteins were detected by western blotting and qRT-PCR to further elucidate its mechanisms. MiR-146 mimics were successfully loaded into the MEs by electroporation at a square wave 1000 V voltage and 0.1 ms pulse duration. MEs-miR-146a can be up-taken by cardiomyocytes and protected the cells from oxygen glucose deprivation/reperfusion induced damage in vitro. Oral administration of MEs-miR-146a decreased myocardial tissue apoptosis and the expression of inflammatory factors and improved cardiac function after MIRI. The miR-146a level in myocardium tissues was significantly increased after the administration IMTP modified MEs-miR-146a, which was higher than that of the MEs-miR-146a group. In addition, intravenous injection of IMTP modified MEs-miR-146a enhanced the targeting to heart, improved cardiac function, reduced myocardial tissue apoptosis and suppressed inflammation after MIRI, which was more effective than the MEs-miR-146a treatment. Moreover, IMTP modified MEs-miR-146a reduced the protein levels of IRAK1, TRAF6 and p-p65. Therefore, IMTP modified MEs-miR-146a exerted their anti-inflammatory effect by inhibiting the IRAK1/TRAF6/NF-κB signaling pathway. Taken together, our findings suggested miR-146a containing MEs may be a promising strategy for the treatment of MIRI with better outcome after modification with ischemic myocardium-targeted peptide, which was expected to be applied in clinical practice in future.
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Exosomas , MicroARNs , Daño por Reperfusión Miocárdica , FN-kappa B , Ratas Sprague-Dawley , Transducción de Señal , Animales , MicroARNs/metabolismo , MicroARNs/genética , Daño por Reperfusión Miocárdica/metabolismo , Exosomas/metabolismo , FN-kappa B/metabolismo , Ratas , Masculino , Leche/química , Miocardio/metabolismo , Cardiotónicos/farmacología , Miocitos Cardíacos/metabolismoRESUMEN
Aims: Some gene variants in the sodium channels, as well as calcium channels, have been associated with Brugada syndrome (BrS). However, the investigation of the human cellular phenotype and the use of drugs for BrS in presence of variant in the calcium channel subunit is still lacking. Objectives: The objective of this study was to establish a cellular model of BrS in the presence of a CACNB2 variant of uncertain significance (c.425C > T/p.S142F) using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and test drug effects using this model. Methods and results: This study recruited cells from a patient with Brugada syndrome (BrS) and recurrent ventricular fibrillation carrying a missense variant in CACNB2 as well as from three healthy independent persons. These cells (hiPSC-CMs) generated from skin biopsies of healthy persons and the BrS patient (BrS-hiPSC-CMs) as well as CRISPR/Cas9 corrected cells (isogenic control, site-variant corrected) were used for this study. The hiPSC-CMs from the BrS patient showed a significantly reduced L-type calcium channel current (ICa-L) compared with the healthy control hiPSC-CMs. The inactivation curve was shifted to a more positive potential and the recovery from inactivation was accelerated. The protein expression of CACNB2 of the hiPSC-CMs from the BrS-patient was significantly decreased compared with healthy hiPSC-CMs. Moreover, the correction of the CACNB2 site-variant rescued the changes seen in the hiPSC-CMs of the BrS patient to the normal state. These data indicate that the CACNB2 gene variant led to loss-of-function of L-type calcium channels in hiPSC-CMs from the BrS patient. Strikingly, arrhythmia events were more frequently detected in BrS-hiPSC-CMs. Bisoprolol (beta-blockers) at low concentration and quinidine decreased arrhythmic events. Conclusions: The CACNB2 variant (c.425C > T/p.S142F) causes a loss-of-function of L-type calcium channels and is pathogenic for this type of BrS. Bisoprolol and quinidine may be effective for treating BrS with this variant.
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Síndrome de Brugada , Células Madre Pluripotentes Inducidas , Potenciales de Acción , Arritmias Cardíacas/metabolismo , Bisoprolol/farmacología , Canales de Calcio Tipo L/genética , Canales de Calcio Tipo L/metabolismo , Humanos , Miocitos Cardíacos/metabolismo , Quinidina/farmacologíaRESUMEN
AIMS: This study aimed to investigate possible roles and underlying mechanisms of alpha-adrenoceptor coupled signalling for the pathogenesis of Takotsubo syndrome (TTS). METHODS AND RESULTS: Human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) were treated with a toxic concentration of epinephrine (Epi, 0.5 mM for 1 h) to mimic the setting of TTS. Patch-clamp technique, polymerase chain reaction (PCR) and Fluorescence-activated cell sorting (FACS) were employed for the study. High concentration Epi suppressed the depolarization velocity, prolonged duration of action potentials and induced arrhythmic events in hiPSC-CMs. The Epi effects were attenuated by an alpha-adrenoceptor blocker (phentolamine), suggesting involvement of alpha-adrenoceptor signalling in arrhythmogenesis related to QT interval prolongation in the setting of TTS. An alpha 1-adrenoceptor agonist (phenylephrine) but not an alpha 2-adrenoceptor agonist (clonidine) mimicked Epi effects. Epi enhanced ROS production, which could be attenuated by the alpha- adrenoceptor blocker. Treatment of cells with H2O2 (100 µM) mimicked the effects of Epi on action potentials and a reactive oxygen species (ROS)-blocker (N-acetyl-I-cysteine, 1 mM) prevented the Epi effects, indicating that the ROS signalling is involved in the alpha-adrenoceptor actions. Nicotinamide adenine dinucleotide phosphate hydrogen (NADPH) oxidases were involved in alpha 1-adrenoceptor signalling. A protein kinase C (PKC) blocker suppressed the effects of Epi, phenylephrine and ROS as well, implying that PKC participated in alpha 1-adrenoceptor signalling and acted as a downstream factor of ROS. The abnormal action potentials resulted from alpha 1-adrenoceptor activation-induced dysfunctions of ion channels including the voltage-dependent Na+ and L-type Ca2+ channels. CONCLUSIONS: Alpha 1-adrenoceptor signalling plays important roles for arrhythmogenesis of TTS. Alpha-adrenoceptor blockers might be clinically helpful for treating arrhythmias in patients with TTS.
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Células Madre Pluripotentes Inducidas , Miocitos Cardíacos , Potenciales de Acción , Catecolaminas/toxicidad , Humanos , Peróxido de Hidrógeno , Receptores Adrenérgicos alfa 1RESUMEN
Sleep is a complex physiological process of great significance to physical and mental health, and its research scope involves multiple disciplines. At present, the quantitative analysis of sleep mainly relies on the "gold standard" of polysomnography (PSG). However, PSG has great interference to the human body and cannot reflect the hemodynamic status of the brain. Functional near infrared spectroscopy (fNIRS) is used in sleep research, which can not only meet the demand of low interference to human body, but also reflect the hemodynamics of brain. Therefore, this paper has collected and sorted out the related literatures about fNIRS used in sleep research, concluding sleep staging research, clinical sleep monitoring research, fatigue detection research, etc. This paper provides a theoretical reference for scholars who will use fNIRS for fatigue and sleep related research in the future. Moreover, this article concludes the limitation of existing studies and points out the possible development direction of fNIRS for sleep research, in the hope of providing reference for the study of sleep and cerebral hemodynamics.
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Encéfalo , Espectroscopía Infrarroja Corta , Encéfalo/diagnóstico por imagen , Hemodinámica , Humanos , Polisomnografía , SueñoRESUMEN
Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a poor prognosis and limited therapies, and transforming growth factor-ß1 (TGF-ß1) plays a central role in the pathogenesis of IPF. Here, we aimed to investigate the chemical constituents and biological activities of Hypericum longistylum and detect whether the isolated compounds inhibit the TGF-ß1/Smad3 signaling pathway to identify candidate compounds for the treatment of pulmonary fibrosis. Fifteen compounds (1-15) were isolated from H. longistylum and their structures were elucidated on the basis of spectroscopic analyses. An in vitro MTT assay was used to test the effect of these fifteen compounds on fibroblast cytotoxicity and vitality. Furthermore, their bioactivities were screened using a TGF-ß1/Smad3 pathway luciferase reporter in vitro. MTT screening found that compounds 1-15 had no deleterious effects on normal mouse lung fibroblasts and no significant inhibition of vitality. Luciferase assay showed that compounds 14 and 15 could significantly inhibit the TGF-ß1/Smad3 pathway with the inhibition rates of 67.92% and 93.10%, respectively. Both compounds can be used as lead compounds for structural modification and optimization to obtain more drug candidates for the treatment of pulmonary fibrosis.
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Antifibrinolíticos/farmacología , Hypericum/química , Extractos Vegetales/farmacología , Fibrosis Pulmonar/tratamiento farmacológico , Animales , Antifibrinolíticos/química , Antifibrinolíticos/aislamiento & purificación , Supervivencia Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Fibroblastos/efectos de los fármacos , Ratones , Estructura Molecular , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Transducción de Señal/efectos de los fármacos , Proteína smad3/antagonistas & inhibidores , Proteína smad3/metabolismo , Relación Estructura-Actividad , Factor de Crecimiento Transformador beta1/antagonistas & inhibidores , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
AIMS: Brugada syndrome (BrS) is associated with a pronounced risk to develop sudden cardiac death (SCD). Up to 21% of patients are related to mutations in SCN5A. Studies identified SCN10A as a contributor of BrS. However, the investigation of the human cellular phenotype of BrS in the presence of SCN10A mutations remains lacking. The objective of this study was to establish a cellular model of BrS in presence of SCN10A mutations using human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). METHODS AND RESULTS: Dermal fibroblasts obtained from a BrS patient suffering from SCD harbouring the SCN10A double variants (c.3803G>A and c.3749G>A) and three independent healthy control subjects were reprogrammed to hiPSCs. Human-induced pluripotent stem cells were differentiated into cardiomyocytes (hiPSC-CMs).The hiPSC-CMs from the BrS patient showed a significantly reduced peak sodium channel current (INa) and a significantly reduced ATX II (sea anemone toxin, an enhancer of late INa) sensitive as well as A-887826 (a blocker of SCN10A channel) sensitive late sodium channel current (INa) when compared with the healthy control hiPSC-CMs, indicating loss-of-function of sodium channels. Consistent with reduced INa the action potential amplitude and upstroke velocity (Vmax) were significantly reduced, which may contribute to arrhythmogenesis of BrS. Moreover, Ajmaline effects on action potentials were stronger in BrS-hiPSC-CMs than in healthy control cells. This is in agreement with the higher susceptibility of patients to sodium channel blocking drugs in unmasking BrS. CONCLUSION: Patient-specific hiPSC-CMs are able to recapitulate single-cell phenotype features of BrS with SCN10A mutations and may provide novel opportunities to further elucidate the cellular disease mechanism.
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Potenciales de Acción/fisiología , Síndrome de Brugada/genética , Miocitos Cardíacos/metabolismo , Canal de Sodio Activado por Voltaje NAV1.8/genética , Potenciales de Acción/efectos de los fármacos , Potenciales de Acción/genética , Ajmalina/farmacología , Síndrome de Brugada/metabolismo , Cardiotónicos/farmacología , Estudios de Casos y Controles , Técnicas de Reprogramación Celular , Venenos de Cnidarios/farmacología , Muerte Súbita Cardíaca , Humanos , Células Madre Pluripotentes Inducidas , Mutación con Pérdida de Función , Masculino , Persona de Mediana Edad , Morfolinas/farmacología , Mutación , Miocitos Cardíacos/efectos de los fármacos , Canal de Sodio Activado por Voltaje NAV1.8/metabolismo , Niacinamida/análogos & derivados , Niacinamida/farmacología , Técnicas de Placa-Clamp , Fenotipo , Taquicardia Ventricular , Bloqueadores del Canal de Sodio Activado por Voltaje/farmacologíaRESUMEN
Organophosphate (OP) and pyrethroid (PYR) pesticides are widely used in China. However, few studies have investigated the neurobehavioral outcomes of Chinese children exposed to low levels of OP and PYR. We investigated urinary metabolite levels and their association with exposure characteristics and the neurobehavior of children. For all children, biomarker measurements were made in the same interval relative to neurobehavioral testing. We analyzed the morning urine samples of 406 children aged 3-6 years from Nanjing, China. The Kruskal-Wallis and Wilcoxon rank sum tests were used to identify the associations between urinary metabolite levels and exposure characteristics. Multiple linear regression models were used to test the associations between urinary metabolite levels and neurobehavioral test scores after adjusting for covariates (e.g., sex, age, and education expense). The detection of 3,5,6-trichloropyridinol (TCP) and 3-phenoxybenzoic acid (3-PBA) in the urine was positively associated with living areas adjacent to agricultural fields and using indoor mosquito repellent incense. These two metabolites were negatively associated with the soaking time of fruits and vegetables. When treated as dichotomous variables, TCP was significantly associated with arithmetic test scores in adjusted models, and 3-PBA was significantly associated with the scores on the Chinese Binet and arithmetic tests. When treated as a continuous variable, higher urinary 3-PBA levels were significantly associated with lower cancellation test scores. Our findings suggest that exposure to organophosphate and pyrethroid pesticides may have a significant impact on children's working memory and verbal comprehension.
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Plaguicidas/orina , Piretrinas/orina , Biomarcadores/orina , Niño , Conducta Infantil , Desarrollo Infantil , Preescolar , Exposición a Riesgos Ambientales , Frutas , Humanos , Organofosfatos/orinaRESUMEN
INTRODUCTION: This study aimed to analyze changes in cardiovascular disease (CVD) mortality attributable to major environmental risks in China during 1990-2019, and their associations with age, period, and birth cohort. METHODS: Mortality data were obtained from the Global Burden of Disease Study 2019. Major environmental risks included ambient particulate matter pollution (APMP), household air pollution from solid fuels (HAP), low temperature, high temperature, and lead exposure. Age-period-cohort modeling was used to estimate the overall annual percentage change in CVD mortality (net drift), annual percentage change for each age group (local drift), expected longitudinal age-specific rate (longitudinal age curve), period and cohort relative risks (RRs, period/cohort effects) between 1990 and 2019. Analyses were conducted in 2021-2022. RESULTS: In China, five major environmental risks led to 1.62 million CVD deaths in 2019. Among these risks, the primary contributor to CVD mortality transited from HAP in 1990 to APMP in 2019. There was also an improvement in attributable CVD mortality rates for low temperature and lead exposure during 1990-2019, while an unfavorable trend was noted for high temperature. The longitudinal age curve demonstrated increased attributable CVD mortality rates with age groups for all environmental risks, with similar patterns for both sexes. Period and cohort RRs suggested generally improved risks of attributable CVD mortality for HAP, low temperature, and lead exposure, but worsening risks for APMP and high temperature in both genders, except for period risks after 2010-2014 for APMP in both sexes, period risks after 2000-2004 for high temperature in females, and cohort risks in cohorts born after 1955 for APMP and high temperature in females. CONCLUSIONS: Over the study period, there was a significant improvement in attributable CVD mortality rates in China for HAP, low temperature and lead exposure, but an unfavorable trend was noted for APMP and high temperature.
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Contaminación del Aire , Enfermedades Cardiovasculares , Humanos , Masculino , Femenino , Plomo , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Material Particulado/efectos adversos , Material Particulado/análisis , Riesgo , China/epidemiología , Exposición a Riesgos Ambientales/efectos adversosRESUMEN
OBJECTIVES: The objective of this study was to investigate the resistance mechanisms of a multidrug-resistant Salmonella Kentucky ST198 FJ-2064 isolated from a patient in China. METHODS: The antimicrobial susceptibility of FJ-2064 was determined by the standard disc dilution and broth microdilution methods. The complete genome of FJ-2064 was sequenced using PacBio and Illumina MiSeq platforms. Polymerase chain reaction (PCR) and S1-PFGE were utilized to confirm the mutation sites and the genomic plasmids, respectively. RESULTS: Isolate FJ-2064 belongs to sequence type ST198 and harboured no visible large plasmids, but was concurrent resistant to 22 detected antimicrobial agents including cefotaxime, ciprofloxacin, and azithromycin. The complete genome sequence identified 20 acquired antibiotic resistance genes (ARGs) and five chromosomal mutations in the gyrA and parC genes of the quinolone resistance determining regions (QRDRs) in FJ-2064. In addition, PCR sequencing confirmed that most of the ARGs were clustered on one multidrug-resistant region and a variant of SGI1-K. In particular, the bla-TEM-1 and bla-CTX-M-55, qnrS1, mph(A) genes, which confer resistance to cephalosporins, quinolones, and macrolides respectively, were all located on the multidrug-resistant region. CONCLUSIONS: We have demonstrated one multidrug-resistant region and a variant of SGI1-K in a Salmonella Kentucky ST198 that is co-resistant to cefotaxime, ciprofloxacin, and azithromycin.
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The lysine acetyltransferase KAT5 is a pivotal enzyme responsible for catalyzing histone H4 acetylation in cells. In addition to its indispensable HAT domain, KAT5 also encompasses a conserved Tudor-knot domain at its N-terminus. However, the function of this domain remains elusive, with conflicting findings regarding its role as a histone reader. In our study, we have employed a CRISPR tiling array approach and unveiled the Tudor-knot motif as an essential domain for cell survival. The Tudor-knot domain does not bind to histone tails and is not required for KAT5's chromatin occupancy. However, its absence leads to a global reduction in histone acetylation, accompanied with genome-wide alterations in gene expression that consequently result in diminished cell viability. Mechanistically, we find that the Tudor-knot domain regulates KAT5's HAT activity on nucleosomes by fine-tuning substrate accessibility. In summary, our study uncovers the Tudor-knot motif as an essential domain for cell survival and reveals its critical role in modulating KAT5's catalytic efficiency on nucleosome and KAT5-dependent transcriptional programs critical for cell viability.
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Histonas , Lisina Acetiltransferasa 5 , Nucleosomas , Dominio Tudor , Acetilación , Cromatina/metabolismo , Histonas/genética , Histonas/metabolismo , Nucleosomas/metabolismo , Lisina Acetiltransferasa 5/química , Lisina Acetiltransferasa 5/genética , Lisina Acetiltransferasa 5/metabolismo , HumanosRESUMEN
Atomically dispersed Co-N4-based catalysts have been recently emerging as one of the most promising candidates for facilitating CO2 reduction reaction (CO2RR). The local electronic environment of Co-N4 sites in these catalysts is considered to play a critical role in adjusting the catalytic performance, the effort of which however is not yet clearly verified. Herein, a series of cobalt phthalocyanines with different peripheral substituents including unsubstituted phthalocyanine Co(II) (CoPc), 2,9,16,23-tetramethoxyphthalocyaninato Co(II) (CoPc-4OCH3), and 2,9,16,23-tetranitrophthalocyaninato Co(II) (CoPc-4NO2) are supported onto the surface of the multi-walled carbon nanotubes (CNTs), affording CoPc@CNTs, CoPc-4OCH3@CNTs, and CoPc-4NO2@CNTs. X-ray photoelectron spectroscopy and X-ray absorption near-edge structure measurements disclose the influence of the peripheral substituents on the local electronic structure of Co atoms in these three catalysts. Electrochemical tests indicate the higher CO2RR performance of CoPc-4OCH3@CNTs compared to CoPc@CNTs and CoPc-4NO2@CNTs as exemplified by the higher Faraday efficiency of CO, larger part current densities, and better stability displayed by CoPc-4OCH3@CNTs at the applied voltage range from -0.6 to -1.0 V versus RHE in both H-cell and flow cell. These results highlight the effect of the electron-donating -OCH3 substituent on the enhanced catalytic activity of CoPc-4OCH3@CNTs, which will help develop Co-N4-based catalysts with promising catalytic performance toward CO2RR.
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The histone acylation reader eleven-nineteen leukemia (ENL) plays a pivotal role in sustaining oncogenesis in acute leukemias, particularly in mixed-lineage leukemia-rearranged (MLL-r) leukemia. ENL relies on its reader domain to recognize histone lysine acylation promoting oncogenic gene expression and leukemia progression. Here, we report the development of MS41, a highly potent and selective von Hippel-Lindau-recruiting ENL degrader that effectively inhibits the growth of ENL-dependent leukemia cells. MS41-induced ENL degradation reduces the chromatin occupancy of ENL-associated transcription elongation machinery, resulting in the suppression of key oncogenic gene expression programs and the activation of differentiation genes. MS41 is well-tolerated in vivo and substantially suppresses leukemia progression in a xenograft mouse model of MLL-r leukemia. Notably, MS41 also induces the degradation of mutant ENL proteins identified in Wilms' tumors. Our findings emphasize the therapeutic potential of pharmacological ENL degradation for treating ENL-dependent cancers, making MS41 not only a valuable chemical probe but also potential anticancer therapeutic for further development.
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Progresión de la Enfermedad , Leucemia , Humanos , Animales , Ratones , Línea Celular Tumoral , Leucemia/genética , Leucemia/patología , Leucemia/tratamiento farmacológico , Leucemia/metabolismo , Factores de Elongación Transcripcional/metabolismo , Factores de Elongación Transcripcional/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Proteolisis/efectos de los fármacos , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo , Proliferación Celular/efectos de los fármacosRESUMEN
The development of breast cancer is usually related to multiple pathways. A combinatory therapeutic system that combines drug/siRNA targeting several independent pathways has become an attractive approach to reduce the side effects and improve the efficiency of antitumor drugs. Herein, we designed a unique micelle-liposome hybrid nanoparticle platform for the combinatory administration of the cytotoxic drug DOX and Sphk2-siRNA for the treatment of multidrug-resistant (MDR) cancer. The synthesized lipid dioleoyl ethanolamine (DE) and pH-responsive DOPE were used to produce DOX/siRNA co-loaded hybrid nanoparticle (DOX-MC-siSphk2/ASLNP), with high drug-loading capacity and transfection efficacy. We demonstrated that simultaneous cellular endocytosis of DOX/siRNA induced by nanoparticles in MCF-7/ADR cells could acquire higher drug cytotoxicity and contribute to increasing the apoptosis of tumor cell. Furthermore, DOX-MC-siSphk2/ASLNP could significantly block the tumor growth of MDR breast cancer in xenograft mouse model with lower cardiotoxicity.
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Antineoplásicos , Neoplasias de la Mama , Nanopartículas , Humanos , Animales , Ratones , Femenino , ARN Interferente Pequeño/farmacología , Resistencia a Antineoplásicos , Doxorrubicina/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Antineoplásicos/farmacología , Células MCF-7 , LípidosRESUMEN
Sleep deprivation impairs learning and memory. The neuroprotective function of ginsenoside Rg1 (Rg1) has been reported. This study aimed to investigate the alleviative effect and underlying mechanism of action of Rg1 on learning and memory deficits induced by sleep deprivation. Using 72â h of LED light to establish sleep deprivation model and treatment with Rg1-L (0.5â mg/ml), Rg1-H (1â mg/ml), and melatonin (positive control, 0.25â mg/ml), we investigated the behavioral performance of sleep deprivation zebrafish through 24â h autonomous movement tracking, a novel tank diving test, and a T-maze test. Brain injuries and ultrastructural changes were observed, brain water content was measured, and apoptotic events were analyzed using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining. The oxidation-associated biomarkers superoxide dismutase, catalase, and glutathione peroxidase activity and lipid peroxidation product malondialdehyde content were detected. Real-time PCR and western blotting were performed to detect the levels of apoptotic molecules (Bax, caspase-3, and Bcl-2). Rg1-treatment was observed to improve the behavioral performance of sleep-deprivation fish, alleviate brain impairment, and increase oxidative stress-related enzyme activity. Rg1 can effectively exhibit neuroprotective functions and improve learning and memory impairments caused by sleep deprivation, which could be mediated by the Bcl-2/Bax/caspase-3 apoptotic signaling pathway (see Supplementary Video Abstract, Supplemental digital content, http://links.lww.com/WNR/A702 which demonstrates our research objectives, introduction overview of Rg1, and main direction of future research).
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Privación de Sueño , Pez Cebra , Animales , Caspasa 3 , Privación de Sueño/complicaciones , Privación de Sueño/tratamiento farmacológico , Proteína X Asociada a bcl-2 , Apoptosis , Trastornos de la Memoria/tratamiento farmacológico , Trastornos de la Memoria/etiología , Aprendizaje por LaberintoRESUMEN
Introduction: Toxigenic Vibrio cholerae serogroup O1 and O139 are the pathogens responsible for the global cholera epidemic. V. cholerae can settle in the water and spread via the fecal-oral route. Rapid and accurate monitoring of live V. cholerae in environmental water has become an important strategy to prevent and control cholera transmission. Conventional plate counting is widely used to detect viable bacteria but requires time and effort. Methods: This study aims to develop a new assay that combines triplex droplet digital PCR (ddPCR) with propidium monoazide (PMA) treatment for quantitatively detecting live V. cholerae O1/O139 and cholera enterotoxin. Specific primers and probes were designed according to the conserved regions of gene rfb O1, rfb O139, and ctxA. The amplification procedures and PMA treatment conditions were optimized. The specificity, sensitivity, and ability of PMA-ddPCR to detect viable bacteria-derived DNA were evaluated in simulated seawater samples. Results and Discussion: The results revealed that the optimal primer concentrations of rfb O1, rfb O139, and ctxA were 1 µM, while the concentrations of the three probes were 0.25, 0.25, and 0.4 µM, respectively. The best annealing temperature was 58°C to obtain the most accurate results. The optimal strategy for distinguishing dead and live bacteria from PMA treatment was incubation at the concentration of 20 µM for 15 min, followed by exposure to a 650-W halogen lamp for 20 min. In pure culture solutions, the limit of detection (LODs) of V. cholerae O1 and O139, and ctxA were 127.91, 120.23 CFU/mL, and 1.5 copies/reaction in PMA-triplex ddPCR, respectively, while the LODs of the three targets were 150.66, 147.57 CFU/mL, and 2 copies/reaction in seawater samples. The PMA-ddPCR sensitivity was about 10 times higher than that of PMA-qPCR. When detecting spiked seawater samples with live bacterial concentrations of 1.53 × 102 and 1.53 × 105 CFU/mL, the assay presented a higher sensitivity (100%, 16/16) than qPCR (50.00%, 8/16) and a perfect specificity (100%, 9/9). These results indicate that the developed PMA-triplex ddPCR is superior to the qPCR regarding sensitivity and specificity and can be used to rapidly detect viable toxigenic V. cholerae O1 and O139 in suspicious seawater samples.
RESUMEN
The histone acetyltransferase p300/CBP is composed of several conserved domains, among which, the TAZ2 domain is known as a protein-protein interaction domain that binds to E1A and various transcription factors. Here we show that TAZ2 has a HAT autoinhibitory function. Truncating p300/CBP at TAZ2 leads to hyperactive HAT and elevated histone H3K27 and H3K18 acetylation in cells. Mechanistically, TAZ2 cooperates with other HAT neighboring domains to maintain the HAT active site in a 'closed' state. Truncating TAZ2 or binding of transcription factors to TAZ2 induces a conformational change that 'opens' the active site for substrate acetylation. Importantly, genetic mutations that lead to p300/CBP TAZ2 truncations are found in human cancers, and cells with TAZ2 truncations are vulnerable to histone deacetylase inhibitors. Our study reveals a function of the TAZ2 domain in HAT autoinhibitory regulation and provides a potential therapeutic strategy for the treatment of cancers harboring p300/CBP TAZ2 truncations.
Asunto(s)
Inhibidores de Histona Desacetilasas , Histonas , Humanos , Acetilación , Inhibidores de Histona Desacetilasas/farmacología , Inhibición Psicológica , Factores de Transcripción/genéticaRESUMEN
BACKGROUND: Brugada syndrome (BrS) is causing sudden cardiac death (SCD) mainly at young age. Studying the underlying mechanisms associated with BrS type I electrocardiogram (ECG) changes in the presence of fever and roles of autophagy for BrS remains lacking. OBJECTIVES: We sought to study the pathogenic role of an SCN5A gene variant for BrS with fever-induced type 1 ECG phenotype. In addition, we studied the role of inflammation and autophagy in the pathomechanism of BrS. METHODS: Human-induced pluripotent stem cell (hiPSC) lines from a BrS patient harboring a pathogenic variant (c.3148G>A/p. Ala1050Thr) in SCN5A and two healthy donors (non-BrS) and a CRISPR/Cas9 site-corrected cell line (BrS-corr) were differentiated into cardiomyocytes (hiPSC-CMs) for the study. RESULTS: Reductions of Nav 1.5 expression, peak sodium channel current (INa ) and upstroke velocity (Vmax ) of action potentials with an increase in arrhythmic events were detected in BrS compared to non-BrS and BrS-corr cells. Increasing the cell culture temperature from 37 to 40°C (fever-like state) exacerbated the phenotypic changes in BrS cells. The fever-effects were enhanced by protein kinase A (PKA) inhibitor but reversed by PKA activator. Lipopolysaccharides (LPS) but not increased temperature up to 40°C enhanced the autophagy level in BrS-hiPSC-CMs by increasing reactive oxidative species and inhibiting PI3K/AKT signalling, and hence exacerbated the phenotypic changes. LPS enhanced high temperature-related effect on peak INa shown in BrS hiPSC-CMs. Effects of LPS and high temperature were not detected in non-BrS cells. CONCLUSIONS: The study demonstrated that the SCN5A variant (c.3148G>A/p.Ala1050Thr) caused loss-of-function of sodium channels and increased the channel sensitivity to high temperature and LPS challenge in hiPSC-CMs from a BrS cell line with this variant but not in two non-BrS hiPSC-CM lines. The results suggest that LPS may exacerbate BrS phenotype via enhancing autophagy, whereas fever may exacerbate BrS phenotype via inhibiting PKA-signalling in BrS cardiomyocytes with but probably not limited to this variant.