RESUMEN
Although cardiac hypertrophy is widely recognized as a risk factor that leads to cardiac dysfunction and, ultimately, heart failure, the complex mechanisms underlying cardiac hypertrophy remain incompletely characterized. The nuclear receptor peroxisome proliferator-activated receptor δ (PPARδ) is involved in the regulation of cardiac lipid metabolism. Here, we describe a novel PPARδ-dependent molecular cascade involving microRNA-29a (miR-29a) and atrial natriuretic factor (ANF), which is reactivated in cardiac hypertrophy. In addition, we identify a novel role of miR-29a, in which it has a cardioprotective function in isoproterenol hydrochloride-induced cardiac hypertrophy by targeting PPARδ and downregulating ANF. Finally, we provide evidence that miR-29a reduces the isoproterenol hydrochloride-induced cardiac hypertrophy response, thereby underlining the potential clinical relevance of miR-29a in which it may serve as a potent therapeutic target for heart hypertrophy treatment.
Asunto(s)
Factor Natriurético Atrial/metabolismo , Cardiomegalia/metabolismo , Regulación de la Expresión Génica/fisiología , MicroARNs/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Animales , Regulación hacia Abajo , Ratones , Ratones Endogámicos ICR , Miocitos Cardíacos/metabolismoRESUMEN
Research shows that redox complementarity and synergism among the ingredients of heterogeneous catalysts can enhance the performance of the catalyst. In this research, a porous CuMoO4@Co3O4 nanosheet electrocatalyst is prepared, which is uniformly decorated on nickel foam (NF) by hydrothermal reactions and the impregnation method. The CuMoO4@Co3O4 is an efficient bifunctional catalyst with prominent electrocatalytic activity and durability. It requires overpotentials of only 54 and 251 mV to obtain current densities of 10 and 50 mA cm-2 for the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER) in 1.0 mol L-1 KOH, corresponding to Tafel slope values of 98.8 and 87.4 mV dec-1, respectively. Furthermore, the CuMoO4@Co3O4 shows excellent stability of 120 h chronopotentiometry at a current density of 100 mA cm-2 for the HER/OER. Notably, an alkaline electrolyzer (with CuMoO4@Co3O4 as the HER and OER electrodes) can deliver a current density of 10 mA cm-2 at a low voltage of 1.51 V. The catalytic activity of CuMoO4@Co3O4 can be attributed to the structure of the porous nanosheets and the synergistic effect between CuMoO4 and Co3O4.
RESUMEN
The development of electrode materials with a high specific capacitance, power density, and long-term stability is essential and remains a challenge for developing supercapacitors. Cobalt sulfides (CoS2) are considered one of the most promising and widely studied electrode materials for supercapacitors. Herein, CoS2 and hierarchical porous carbon derived from Pien Tze Huang waste are assembled into a cobalt sulfide/carbon (CoS2/PZH) matrix composite using a one-step hydrothermal method to resolve the challenges of supercapacitors. The resulting CoS2/PZH composite material exhibits a hierarchical porous structure with hollow CoS2 embedded in a PZH framework. The uniform dispersion of the hierarchical porous structure CoS2/PZH is achieved due to the PZH framework, while the uniform decoration of the porous PZH with the hollow CoS2 prevents the PZH from stacking easily. Moreover, the excellent synergistic effect of the hierarchical porous and hollow structure of CoS2/PZH can shorten the electron/ion diffusion channels, expose additional active sites, and provide stable structures for subsequent reactions. As a result, the CoS2/PZH composite material displays a high initial specific capacity of 447.5 F g-1 at 0.5 A g-1, a high energy density of 22.38 W h kg-1, and long-term cycling stability (a retention rate of 92.3% over 10 000 cycles at 5 A g-1).
RESUMEN
Phenol and its chemical derivatives serve as essential chemical materials are indispensable for the synthesis of many kinds of polymers. However, they are highly toxic, carcinogenic, difficult to be degraded biologically, and often found in aqueous effluents. Recovery of hazardous phenol from wastewater remains a daunting challenge. Herein, we prepared a hybrid membrane containing polyether block amide (PEBA) matrix and HZIF-8 fillers. To improve the compatibility between ZIF-8 and PEBA, ZIF-8 was modified by using polystyrene (PS) as a template to prepare porous HZIF-8. ZIF-8, composed of zinc nodes linked by the imidazole ring skeleton, is a kind of inorganic material with high hydrothermal stability, ordered pores, and hydrophobic microporous surfaces, which has a wide range of applications in membrane separation. The separation performance of the PEBA/HZIF-8 based membranes for phenol/water is improved due to the presence of PS on the surface of HZIF-8 and the imidazole ring skeleton in ZIF-8, which enhance the π-π interaction between HZIF-8 and phenol molecules. The effects of HZIF-8 content, feed phenol concentration, and feed temperature on the pervaporation performance of PEBA/HZIF-8 membranes were further investigated. The results showed that the pervaporation performance of the PEBA/HZIF-8-10 membrane was promising with a separation factor of 80.89 and permeate flux of 247.70 g/m2·h under the feed phenol concentration of 0.2 wt % at 80 °C. In addition, the PEBA/HZIF-8-10 membrane presented excellent stability, which has great prospect for practical application in phenol recovery from waste water.
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Terminal differentiation failure is an important cause of rhabdomyosarcoma genesis, however, little is known about the epigenetic regulation of aberrant myogenic differentiation. Here, we show that GATA-4 recruits polycomb group proteins such as EZH2 to negatively regulate miR-29a in undifferentiated C2C12 myoblast cells, whereas recruitment of GRIP-1 to GATA-4 proteins displaces EZH2, resulting in the activation of miR-29a during myogenic differentiation of C2C12 cells. Moreover, in poorly differentiated rhabdomyosarcoma cells, EZH2 still binds to the miR-29a promoter with GATA-4 to mediate transcriptional repression of miR-29a. Interestingly, once re-differentiation of rhabdomyosarcoma cells toward skeletal muscle, EZH2 was dispelled from miR-29a promoter which is similar to that in myogenic differentiation of C2C12 cells. Eventually, this expression of miR-29a results in limited rhabdomyosarcoma cell proliferation and promotes myogenic differentiation. We thus establish that GATA-4 can function as a molecular switch in the up- and downregulation of miR-29a expression. We also demonstrate that GATA-4 acts as a tumor suppressor in rhabdomyosarcoma partly via miR-29a, which thus provides a potential therapeutic target for rhabdomyosarcoma.
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MicroARNs , Rabdomiosarcoma Embrionario , Rabdomiosarcoma , Animales , Ratones , Diferenciación Celular/genética , Proliferación Celular/genética , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Epigénesis Genética , MicroARNs/metabolismo , Mioblastos , Rabdomiosarcoma/patología , Rabdomiosarcoma Embrionario/patologíaRESUMEN
Circular RNA (circRNA) is a novel class of noncoding RNAs, and the roles of circRNAs in the development of cardiac hypertrophy remain to be explored. Here, we investigate the potential roles of circRNAs in cardiac hypertrophy. By circRNA sequencing in left ventricular specimens collected from 8-week-old mice with isoproterenol hydrochloride-induced cardiac hypertrophy, we found 401 out of 3323 total circRNAs were dysregulated in the hypertrophic hearts compared with the controls. Of these, 303 circRNAs were upregulated and 98 were downregulated. Moreover, the GO and KEGG analyses revealed that the majority of parental gene of differentially expressed circRNAs were not only related to biological process such as metabolic process and response to stimulus, but also related to pathway such as circulatory system and cardiovascular diseases. On the other hand, total 1974 miRNAs were predicted to binding to these differentially expressed circRNAs, and the possible target mRNAs of those miRNAs were also predicted and analyzed in terms of functional annotation. Finally, we identified that ANF and miR-23a are downstream targets of circRNA wwp1, suggesting that circRNA wwp1 exerts inhibitory roles of cardiac hypertrophy via down-regulation of ANF and miR-23a, which underlying the potential mechanisms whereby circRNA regulates cardiac hypertrophy.
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Cardiomegalia/inducido químicamente , Cardiomegalia/genética , Regulación de la Expresión Génica/genética , Isoproterenol/toxicidad , ARN Circular/metabolismo , Animales , Factor Natriurético Atrial/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/efectos de los fármacos , Ratones , MicroARNs/metabolismo , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
A total of eighteen common phytoplankton species in China coastal waters were divided into different assemblages to investigate the increasing pattern of the assemblage biomass with species richness. The sampling effect was studied by multiple analysis of variance (MANOVA) method, and the complementary effect was explored by over-yielding analysis, relative yield total (RYT) index, and subset approach. It was shown that the increasing pattern of assemblage biomass with species richness was not unitary. When the species number was lower than 5, the assemblage biomass increased with increasing species richness; when the species number was higher than 5, there were no obvious relationships between assemblage biomass and species richness. A stronger complementary effect was observed inside the assemblage, presenting a hump-shaped variation with increasing species richness. The sampling effect of the assemblages occurred at stable growth phase.
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Biodiversidad , Biomasa , Ecología/métodos , Fitoplancton/crecimiento & desarrollo , China , Océanos y Mares , Fitoplancton/clasificación , Densidad de Población , Dinámica Poblacional , Especificidad de la EspecieRESUMEN
With eight species of unicellular algae cultured in random combinations to construct the assemblages with different degrees of richness, the increase pattern of colony biomass with the change of species richness was investigated, and the sampling effect was detected by using multiple variance analysis (MANOVA) method. Three analysis methods, i. e., over-yielding analysis, relative yield total (RYT) index, and subset approach, were applied to explore the complementary effect, and additive partitioning method was applied to separate the sampling effect and complementary effect quantitatively. The results showed that the colony biomass presented a saturated rise with the increase of species richness, and a strong complementary effect was observed in phytoplankton colonies. At exponential growth phase, some specific algal species affected the colony biomass significantly, but after reaching the stable phase, the biomass was not affected by the presence of given phytoplankton. The sampling effect was generally negative at stable phase, while the complementary effect and net biodiversity effect were always positive.