The natural compound Zerumbone (hereinafter referred to as ZER), a monocyclic sesquiterpenoid, has been reported to possess many pharmacological properties, including antioxidant and ...anti-inflammatory properties. This study aimed to investigate the underlying mechanism of ZER against acute liver injury (ALI) in CCl
-induced mice models. ICR mice were pretreated intraperitoneally with ZER for five days, then received a CCl
injection two hours after the last ZER administration and were sacrificed 24 h later. Examination of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities and the histopathological analysis confirmed the hepatoprotective effect of ZER. Biochemical assays revealed that ZER pretreatment recovered the activities of antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), restored the glutathione (GSH) reservoir, and reduced the production of malondialdehyde (MDA), all in a dose-dependent manner. Furthermore, administration of ZER in vivo reduced the release amounts of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) and inhibited the increased protein levels of Toll-like receptor 4 (TLR4), nuclear factor-kappaB (NF-κB) p-p65, and cyclooxygenase (COX-2). Further studies in lipopolysaccharide (LPS)-induced Raw264.7 inflammatory cellular models verified that ZER could inhibit inflammation via inactivating the TLR4/NF-κB/COX-2 pathway. Thus, our study indicated that ZER exhibited a hepatoprotective effect against ALI through its antioxidant and anti-inflammatory activities and the possible mechanism might be mediated by the TLR4/NF-κB/COX-2 pathway. Collectively, our studies indicate ZER could be a potential candidate for chemical liver injury treatment.
Chitosan oligosaccharide (COS) plays an important role in the growth and development of tea plants. However, responses in tea plants trigged by COS have not been thoroughly investigated. In this ...study, we integrated transcriptomics and metabolomics analysis to understand the mechanisms of chitosan-induced tea quality improvement and growth promotion. The combined analysis revealed an obvious link between the flourishing development of the tea plant and the presence of COS. It obviously regulated the growth and development of the tea and the metabolomic process. The chlorophyll, soluble sugar, and amino acid content in the tea leaves was increased. The phytohormones, carbohydrates, and amino acid levels were zoomed-in in both transcript and metabolomics analyses compared to the control. The expression of the genes related to phytohormones transduction, carbon fixation, and amino acid metabolism during the growth and development of tea plants were significantly upregulated. Our findings indicated that alerted transcriptomic and metabolic responses occurring with the application of COS could cause efficiency in substrates in pivotal pathways and hence, elicited plant growth.
Chitosan oligosaccharides (COS) has been abundantly studied for its application on regulating plant growth of many horticultural and agricultural crops. We presented here the effect of COS on tea ...plant growth and yield by physiological and transcriptomic checking. The results showed that COS treatment can enhance the antioxidant activity of superoxide dismutase (SOD) and peroxidase (POD) and increase the content of chlorophyll and soluble sugar in tea plants. The field trail results show that COS treatment can increase tea buds’ density by 13.81–23.16%, the weight of 100 buds by 15.94–18.15%, and the yield by 14.22–21.08%. Transcriptome analysis found 5409 COS-responsive differentially expressed genes (DEGs), including 3149 up-regulated and 2260 down-regulated genes, and concluded the possible metabolism pathway that responsible for COS promoting tea plant growth. Our results provided fundamental information for better understanding the molecular mechanisms for COS’s acting on tea plant growth and yield promotion and offer academic support for its practical application in tea plant.
Cold stress caused by a low temperature is a significant threat to tea production. The application of chitosan oligosaccharide (COS) can alleviate the effect of low temperature stress on tea plants. ...However, how COS affects the cold stress signaling in tea plants is still unclear. In this study, we investigated the level of physiological indicators in tea leaves treated with COS, and then the molecular response to the cold stress of tea leaves treated with COS was analyzed by transcriptomics with RNA-Sequencing (RNA-Seq). The results show that the activity of superoxide dismutase (SOD) activity, peroxidase (POD) activity, content of chlorophyll and soluble sugar in tea leaves in COS-treated tea plant were significantly increased and that photosynthesis and carbon metabolism were enriched. Besides, our results suggest that COS may impact to the cold stress signaling via enhancing the photosynthesis and carbon process. Our research provides valuable information for the mechanisms of COS application in tea plants under cold stress.
Four awl-substituted tripyrrinone copper（II） complexes were synthesized and characterized as to their electro- chemical and spectroelectrochemical properties. The examined compounds are represented ...as （YPh）3TPO2Cu, where TPO2 is a dianion of the tripyrrinone and Y is a CH3O, CH3, H or CI substituent on the para-position of each phenyl ring of the compound. The neutral compounds are ESR active and show a typical d9 Cu（II） signal in frozen CH2C12 solution. Each Cu（II） compound undergoes three reductions between -0.61 and -1.90 V and two oxidations between 1.00 and 1.24 V in CH2Cl2 containing 0.1 mol/L tetra-n-butylammonium perchlorate. The potentials for oxidation are similar to those of copper tetraarylporphyrins but the reduction potentials are positively shifted as compared to the corresponding tetraarylporphyrins. Thus, the potential difference between the first one-electron oxidation and first one-electron reduction （the HOMO-LUMO gap） of （YPh）3TPO2Cu, which ranges from 1.68 to 1.75 V, is similar to that of copper corroles （1.73-1.85 V）, but smaller than the separation of 2.30-2.37 V for the copper tetraarylporphyrins under the same solution conditions.
In this article, a data-driven optimal bipartite consensus control (OBCC) scheme is proposed for unknown heterogeneous multi-agent systems (MASs) with time-delay via reinforcement learning (RL) ...algorithm. A directed signed graph is established to construct MASs with cooperative and competitive relationships, and model reduction method is developed to transform MASs with time-delay into a delay-free MASs. Then, based on Bellman's optimal principle, a policy iteration method is utilized to design OBCC strategy. Further, based on Q-function, a model-free Q-function policy iteration algorithm is proposed to solve the OBCC problem for unknown MASs. And, only using input-output states of MASs to tackle the OBCC solution via RL algorithm, and it is implemented by actor-critic neural networks (NNs). Finally, simulation results are given to validate the feasibility and efficiency of the proposed algorithm.
The inhibitory role of p53 in DNA double-strand break （DSB） repair seems contradictory to its tumor-suppressing property. The p53 isoform △113p53/△133p53 is a p53 target gene that antagonizes p53 ...apoptotic activity. However, information on its functions in DNA damage repair is lacking. Here we report that △113p53 expression is strongly induced by T-irradiation, but not by UV-irradiation or heat shock treatment. Strikingly, △113p53 promotes DNA DSB repair pathways, including homologous recombination, non-homologous end joining and single-strand annealing. To study the biological significance of △113p53 in promoting DNA DSB repair, we generated a zebrafish △113p53M/M mutant via the transcription activator-like effector nuclease technique and found that the mutant is more sensitive to y-irradiation. The human ortholog, △133p53, is also only induced by T-irradiation and functions to promote DNA DSB repair. △133p53-knockdown cells were arrested at the G2 phase at the later stage in response to T-irradiation due to a high level of unrepaired DNA DSBs, which finally led to cell senescence. Furthermore, △113p53/△133p53 promotes DNA DSB repair via upregulating the transcription of repair genes rad51, lig4 and rad52 by binding to a novel type of p53-responsive element in their promoters. Our results demonstrate that △113p53/△133p53 is an evolutionally conserved pro-survival factor for DNA damage stress by preventing apoptosis and promoting DNA DSB repair to inhibit cell senescence. Our data also suggest that the induction of △133p53 expression in normal cells or tissues provides an important tolerance marker for cancer patients to radiotherapy.
ABSTRACT
Understanding local stellar kinematic substructures in the solar neighbourhood helps build a complete picture of the formation of the Milky Way, as well as an empirical phase space ...distribution of dark matter that would inform detection experiments. We apply the clustering algorithm hdbscan on the Gaia early third data release to identify a list of stable clusters in velocity space and action-angle space by taking into account the measurement uncertainties and studying the stability of the clustering results. We find 1405 (497) stars in 23 (6) robust clusters in velocity space (action-angle space) that are consistently not associated with noise. We discuss the kinematic properties of these structures and study whether many of the small clusters belong to a similar larger cluster based on their chemical abundances. They are attributed to the known structures: the Gaia Sausage-Enceladus, the Helmi Stream, and globular cluster NGC 3201 are found in both spaces, while NGC 104 and the thick disc (Sequoia) are identified in velocity space (action-angle space). Although we do not identify any new structures, we find that the hdbscan member selection of already known structures is unstable to input kinematics of the stars when resampled within their uncertainties. We therefore present the stable subset of local kinematic structures, which are consistently identified by the clustering algorithm, and emphasize the need to take into account error propagation during both the manual and automated identification of stellar structures, both for existing ones as well as future discoveries.
Constructing heterostructured photocatalysts is an efficient method to improve photocatalytic carbon dioxide (CO2) reduction. Herein, holey g-C3N4 (HGN) with rich amino groups (−NH x ) was hybridized ...with NH2-UiO-66 (NUZ) via a facile in situ growth method. NUZ nanocrystals were anchored on HGN via NHx–Zr–O chemical bonding, leading to the uniform dispersion and avoiding the leaching of NUZ, thus showing excellent stability in photocatalysis. The chemically bonded interfacial charge transfer effect originated from the NHx–Zr–O formation efficiently accelerated the separation and migration of charge carriers, improving the photoactivity. Benefiting from the NHx–Zr–O formation, the optimized NUZ/HGN-35% heterojunctions exhibited outstanding activity in the photoreduction of CO2 to CO (31.6 μmol g–1 h–1), which was about 2 and 3 times higher than that of pure NUZ and HGN under visible-light irradiation. This study is expected to provide useful insights for constructing composites with strong interaction for CO2 reduction, H2 production, and N2 reduction.
Three series of cobalt tetraarylporphyrins were synthesized and characterized by electrochemistry and spectroelectrochemistry. The investigated compounds have the general formula (TpYPP)Co, ...butano(TpYPP)CoII, and benzo(TpYPP)CoII, where TpYPP represents the dianion of the meso-substituted porphyrin, Y is a CH3, H, or Cl substituent on the para position of the four phenyl rings, and butano and benzo are respectively the β- and β′-substituted groups on the four pyrrole rings of the compound. Each porphyrin undergoes one or two reductions depending upon the meso substituent and solvent utilized. Two irreversible reductions are observed for (TpYPP)CoII and butano(TpYPP)CoII in CH2Cl2 containing 0.1 M tetra-n-butylammonium perchlorate; the first leads to the formation of a highly reactive cobalt(I) porphyrin, which can then rapidly react with a solvent to give a CoIIICH2Cl as the product. Only one reversible reduction is seen for benzo(TpYPP)CoII under the same solution conditions, and the one-electron-reduction product is assigned as a cobalt(II) porphyrin π-anion radical. Three oxidations can be observed for each examined compound in CH2Cl2. The first oxidation is metal-centered for the (TpYPP)Co and benzo(TpYPP)CoII derivatives, leading to generation of a cobalt(III) porphyrin with an intact π-ring system, but this redox process is ring-centered in the case of butano(TpYPP)CoII and gives a CoII π-cation radical product. Each porphyrin was also examined as a catalyst for oxygen reduction reactions (ORRs) when adsorbed on a graphite electrode in 1.0 M HClO4. The number of electrons transferred (n) during ORRs is 2.0 for the butano(TpYPP)CoII derivatives, consistent with only H2O2 being produced as a product for the reaction with O2. However, the reduction of O2 using the cobalt benzoporphyrins as catalysts gave n values between 2.6 and 3.1 under the same solution conditions, thus producing a mixture of H2O and H2O2 as the reduction product. This result indicates that the β and β′ substituents have a significant effect on the catalytic properties of the cobalt porphyrins for ORRs in acid media.
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