RÉSUMÉ
Renewable electricity shows immense potential as a driving force for the carbon dioxide reduction reaction (CO2RR) in production of formate (HCOO-) at industrial current density, providing a promising path for value-added chemicals and chemical manufacturing. However, achieving high selectivity and stable production of HCOO- at industrial current density remains a challenge. Here, we present a robust Bi0.6Cu0.4 NSs catalyst capable of regenerating necessary catalytic core (Bi-O) through cyclic voltammetry (CV) treatment. Notably, at 260 mA cm-2, faradaic efficiency of HCOO- reaches an exceptional selectivity to 99.23%, maintaining above 90% even after 400h, which is longest reaction time reported at industrial current density. Furthermore, in stability test, the catalyst was constructed by CV reconstruction to achieve stable and efficient production of HCOO-. In 20h reaction test, the catalyst has a rate of HCOO- production of 13.24mmol m-2 s-1, a HCOO- concentration of 1.91mol L-1, and an energy consumption of 129.80kWh kmol-1. In-situ Raman spectroscopy reveals the formation of Bi-O structure during the gradual transformation of catalyst from Bi0.6Cu0.4 NBs to Bi0.6Cu0.4 NSs. Theoretical studies highlight the pivotal role of Bi-O structure in modifying the adsorption behavior of reaction intermediates, which further reduces energy barrier for *OCHO conversion in CO2RR.
RÉSUMÉ
Epidemiological studies have linked herbicides and Parkinson's disease (PD), with the strongest associations resulting from long exposure durations. Paraquat (PQ), an herbicide, induces PD-like syndromes and has widely been accepted as a PD mimetic. Currently, there is still no cure to prevent the progression of PD, and the search for effective therapeutic ways is urgent. Recently, the impairing activity of sirtuins (SIRTs), such as SIRT1, may correlate with PD etiology. However, the nonspecificity of SIRT1 agonists has made the protective mechanisms against PD unclear and hampered the therapeutic application of SIRT1. Thus, this study investigated the protective mechanism and therapeutic potential of SRT1720, a more specific agonist for SIRT1 synthesized by Sirtris, in alleviating the toxicity of PQ-induced cellular and animal models of PD. Here we show that SRT1720 alleviates PQ-induced toxicity in cell and animal models. Genetic silencing and pharmacological inhibition of SIRT1 attenuated SRT1720's protection against PQ-induced toxicity. Moreover, SRT1720 not only attenuated PQ-induced increased oxidative stress and mitochondrial free radical formations but also decreased mitochondrial membrane potential. Furthermore, SRT1720 reversed PQ-induced decreased PGC-1α levels and mitochondrial biogenesis. Although PQ and SRT1720 elevated NRF2 and antioxidative enzyme levels, only PQ decreased antioxidative enzyme activity but not SRT1720. NRF2 and PGC-1α silencing attenuated SRT1720 protection against PQ-induced toxicity. SRT1720 targeted SIRT1 and activated downstream PGC-1α and NRF2 signalings to prevent PQ-induced toxicity involving oxidative stress and mitochondrial dysfunction. Thus, SRT1720 might have therapeutic potential in preventing PD.
Sujet(s)
Herbicides , Maladie de Parkinson , Animaux , Paraquat/pharmacologie , Sirtuine-1/génétique , Sirtuine-1/métabolisme , Maladie de Parkinson/traitement médicamenteux , Maladie de Parkinson/étiologie , Maladie de Parkinson/métabolisme , Facteur-2 apparenté à NF-E2/génétique , Facteur-2 apparenté à NF-E2/métabolisme , Mitochondries/métabolisme , Stress oxydatif , Herbicides/toxicité , Herbicides/métabolismeRÉSUMÉ
Efficient determination of aldehydes by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is hampered mainly by the low mass and unstable nature of analytes. In the present work, we propose a combined strategy of a reactive metal-organic framework (MOF) matrix for the derivatization and detection of aldehydes. A novel reactive MOF matrix (NH2NH-MOF) was synthesized in two steps. First, NR3+-MOF was synthesized via Cu2+ and the quaternary amine ligand 4,4'-bipyridinium, 1,1â³-(1,2-ethanediyl)bis-, dibromide (PyEtBr). Then, -NHNH2 was introduced to NR3+-MOF through electrostatic adsorption between the -NR3+ and -HSO3- of 4-hydrazinylbenzenesulfonic acid to synthesize NH2NH-MOF. The acid-base chemistry of NH2NH-MOF led to uniform cocrystallization of the aldehyde-matrix mixtures and helped to achieve the detection of low-weight aldehydes with good relative standard deviations (RSDs = 0.07-12.35%). It was confirmed that this strategy can accurately quantify formaldehyde, valeraldehyde, and benzaldehyde with good linearity (r > 0.97). Furthermore, this strategy was applied to quantitatively detect benzaldehyde in wastewater, thus showing potential applications in environmental pollutant detection.
Sujet(s)
Aldéhydes/composition chimique , Hydrazines/composition chimique , Réseaux organométalliques/composition chimique , Spectrométrie de masse MALDI/méthodesRÉSUMÉ
Real-time monitoring of drug delivery in an intravenous infusion system can prevent injury caused by improper drug doses. As the medicine must be administered into the vein at different rates and doses in different people, an ideal intravenous infusion system requires both a low flow rate and large dynamic range monitoring. In this study, a bio-inspired and micromachined volumetric flow sensor is presented for the biomedical application of an intravenous system. This was realized by integrating two sensing units with different sensitivities on one silicon die to achieve a large dynamic range of the volumetric flow rate. The sensor was coated with a parylene layer for waterproofing and biocompatibility purposes. A new packaging scheme incorporating a silicon die into a flow channel was employed to demonstrate the working prototype. The test results indicate that the sensor can detect a volumetric flow rate as low as 2 mL/h, and its dynamic range is from 2 mL/h to 200 mL/h. The sensor performed better than the other two commercial sensors for low-flow detection. The high sensitivity, low cost, and small size of this flow sensor make it promising for intravenous applications.
Sujet(s)
Silicium , HumainsRÉSUMÉ
An adequate imputation of missing data would significantly preserve the statistical power and avoid erroneous conclusions. In the era of big data, machine learning is a great tool to infer the missing values. The root means square error (RMSE) and the proportion of falsely classified entries (PFC) are two standard statistics to evaluate imputation accuracy. However, the Cox proportional hazards model using various types requires deliberate study, and the validity under different missing mechanisms is unknown. In this research, we propose supervised and unsupervised imputations and examine four machine learning-based imputation strategies. We conducted a simulation study under various scenarios with several parameters, such as sample size, missing rate, and different missing mechanisms. The results revealed the type-I errors according to different imputation techniques in the survival data. The simulation results show that the non-parametric "missForest" based on the unsupervised imputation is the only robust method without inflated type-I errors under all missing mechanisms. In contrast, other methods are not valid to test when the missing pattern is informative. Statistical analysis, which is improperly conducted, with missing data may lead to erroneous conclusions. This research provides a clear guideline for a valid survival analysis using the Cox proportional hazard model with machine learning-based imputations.
Sujet(s)
Algorithmes , Apprentissage machine , Simulation numérique , Modèles des risques proportionnels , Analyse de survieRÉSUMÉ
A core-shell material (UiO@TapbTp) has been developed as an adsorbent and matrix to detect nonsteroidal anti-inflammatory drugs (NSAIDS) by matrix laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in complex samples. The hybrid material is prepared by growing covalent organic framework (COF, TapbTp) layers in situ on an amino-modified metal-organic framework (MOF, UiO-66-NH2). The combination of the MOF and COF overcomes their individual shortcomings and integrates both of their advantages. Compared with the bare COF and MOF, the core-shell composite exhibits improved enrichment ability and matrix performance. With the help of pre-enrichment under optimized conditions, the limits of detection (LODs) for ketoprofen, naproxen, and aspirin are reduced by nearly 1000 times, with values of 0.001 mg L-1, 0.010 mg L-1, and 0.001 mg L-1, respectively, and the relative standard deviations (RSDs) are all below 12.35%. The good recoveries (84.8-118%) in (spiked) saliva and environmental water sample further verify the applicability of the method in complex samples.
Sujet(s)
Anti-inflammatoires non stéroïdiens/analyse , Acide acétylsalicylique/analyse , Kétoprofène/analyse , Réseaux organométalliques/composition chimique , Naproxène/analyse , Adsorption , Anti-inflammatoires non stéroïdiens/composition chimique , Acide acétylsalicylique/composition chimique , Eau de boisson/analyse , Kétoprofène/composition chimique , Lacs/analyse , Limite de détection , Naproxène/composition chimique , Salive/composition chimique , Spectrométrie de masse MALDI/méthodes , Polluants chimiques de l'eau/analyse , Polluants chimiques de l'eau/composition chimiqueRÉSUMÉ
A challenge in photocatalysis consists in improving the efficiency by harnessing a large portion of the solar spectrum. We report the design and realization of a robust molecular-semiconductor photocatalytic system (MSPS) consisting of an earth-abundant phytic acid nickel (PA-Ni) biomimetic complex and polymeric carbon nitride (PCN). The MSPS exhibits an outstanding activity at λ=940â nm with high apparent quantum efficiency (AQE) of 2.8 %, particularly λ>900â nm, as it outperforms all reported state-of-the-art near-infrared (NIR) hybrid photocatalysts without adding any noble metals. The optimum hydrogen (H2 ) production activity was about 52 and 64 times higher with respect to its pristine counterpart under the AMâ 1.5 G and visible irradiation, respectively, being equivalent to the platinum-assisted PCN. This work sheds light on feasible avenues to prepare highly active, stable, cheap NIR-harvesting photosystems toward sustainable and scalable solar-to-H2 production.
RÉSUMÉ
Huang Lian Jie Du Tang (HLJDT) is a traditional Chinese medical decoction for heat-fire clearing and detoxication. Theoretically, the cause of Parkinson's disease (PD) has been attributed to the dysregulations of internal wind, phlegm, fire, and stasis. Thus, HLJDT has been used to treat PD. However, the molecular mechanism is unknown. Besides, paraquat (PQ) as an herbicide has been known to impair midbrain dopaminergic neurons, resemblance to the pathology of PD. Thus, the molecular mechanism of HLJDT in treating PD and PQ-induced in vitro PD model was investigated in this study. Primarily, the dose-response of PQ (0.1â¼1 mM)-induced neurotoxicity for 24 h was performed in the human neuroblastoma SH-SY5Y cells. The LD50 of PQ is around 0.3 mM and was applied throughout the following experiments. The neutral red assay was used to estimate cell viability. Co-transfection of the mitochondrial marker and proapoptotic factor genes were applied to measure the release of mitochondrial proapoptotic factors during PQ intoxication and HLJDT protection. The fluorescent dyes were used to detect mitochondrial membrane potential and free radical formation. Western blot and dot-blot analysis and immunocytochemistry were used to estimate the level of proteins related to apoptosis and mitophagy. PINK1 gene silencing was used to determine the significance of mitophagy during PQ intoxication. In this study, HLJDT attenuated PQ-induced apoptosis in SH-SY5Y cells. HLJDT reversed PQ-induced decreased mitochondrial membrane potential and suppressed PQ-induced increased cytosolic and mitochondrial free radical formations and mitochondrial proapoptotic factor releases. Furthermore, HLJDT mitigated PQ-induced increases in full-length PINK1, phosphorylations of Parkin and ubiquitin, mitochondrial translocation of phosphorylated Parkin, and mitophagy. PINK1 gene silencing attenuated PQ-induced neurotoxicity. Therefore, HLJDT attenuated PQ-induced cell death by regulating mitophagy.
Sujet(s)
Antiparkinsoniens/pharmacologie , Médicaments issus de plantes chinoises/pharmacologie , Mitochondries/effets des médicaments et des substances chimiques , Mitophagie/effets des médicaments et des substances chimiques , Neurones/effets des médicaments et des substances chimiques , Paraquat/toxicité , Maladie de Parkinson/traitement médicamenteux , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Humains , Potentiel de membrane mitochondriale/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Mitochondries/anatomopathologie , Neurones/métabolisme , Neurones/anatomopathologie , Maladie de Parkinson/métabolisme , Maladie de Parkinson/anatomopathologie , Phosphorylation , Protein kinases/génétique , Protein kinases/métabolisme , Ubiquitine/métabolisme , Ubiquitin-protein ligases/métabolismeRÉSUMÉ
A nanoprobe of laser desorption/ionization-time of flight mass spectrometry (LDI-TOF MS) for the determination of small molecules was developed that is based on the composition of Fe-metal organic frameworks (Fe-MOFs) and carboxymethyl cellulose-Na (CMC-Na). This material is a good adsorbent for small molecules via hydrogen bonding and π-interactions; we detected three molecules, dopamine, glyphosate, and pyrene. The detection limits for these compounds are 0.01 mg L-1, 1.50 µg L-1, and 0.01 µg L-1, respectively; the recoveries are 85-117%, 81-127%, and 89-115%, respectively. The relative standard deviations (~ 15%) and coefficients of determination of the calibration plot (~ 0.97) are satisfactory. The applicability of the chip for practical samples is demonstrated by quantifying pyrene in domestic water and polluted lake water; the recoveries are about 90~117% and 85~125% (n = 5), respectively; the RSDs are 9.4% and 13.5%, respectively. Graphical abstract.
RÉSUMÉ
Multitarget agents simultaneously trigger molecules in functionally complementary pathways, and are therefore considered to have potential in effectively treating Alzheimer's disease (AD), which has a complex pathogenetic mechanism. In this study, the HDAC inhibitor core is incorporated into the acetylcholine esterase (ACE) inhibitor acridine-derived moiety and resulted in compounds that exhibited higher class IIa HDAC (4, 5, 7, and 9)- and class IIb HDAC6-inhibiting activity when compared to the pan-HDAC inhibitor SAHA in clinical practice. One of these compounds, 11b, displayed greater selectivity toward HDAC6 than other isoform enzymes. In contrast, the activity of compound 6a was selective toward class IIa HDAC and HDAC6. These two compounds exhibited strong activity against Aß-aggregation as well as significantly disrupted Aß-oligomer. Additionally, 11b and 6a strongly inhibited AChE. These experimental findings demonstrate that compounds 11b and 6a are HDAC-Aß-aggregation-AChE inhibitors. Notably, they can enhance neurite outgrowth, but with no significant neurotoxicity. Further biological evaluation revealed the various cellular effects of multitarget compounds 11b and 6a, which have the potential to treat AD.
Sujet(s)
Acridines/pharmacologie , Maladie d'Alzheimer/traitement médicamenteux , Inhibiteurs de désacétylase d'histone/pharmacologie , Histone deacetylases/métabolisme , Acetylcholinesterase/métabolisme , Acridines/synthèse chimique , Acridines/composition chimique , Maladie d'Alzheimer/métabolisme , Peptides bêta-amyloïdes/antagonistes et inhibiteurs , Peptides bêta-amyloïdes/métabolisme , Animaux , Survie cellulaire/effets des médicaments et des substances chimiques , Anticholinestérasiques/synthèse chimique , Anticholinestérasiques/composition chimique , Anticholinestérasiques/pharmacologie , Relation dose-effet des médicaments , Inhibiteurs de désacétylase d'histone/synthèse chimique , Inhibiteurs de désacétylase d'histone/composition chimique , Humains , Souris , Structure moléculaire , Fragments peptidiques/antagonistes et inhibiteurs , Fragments peptidiques/métabolisme , Agrégats de protéines/effets des médicaments et des substances chimiques , Relation structure-activité , Cellules cancéreuses en cultureRÉSUMÉ
As a green and preferred technology for energy crisis and environmental issues, continuous research on photocatalysis and gas sensing has come forth at an explosive rate. Thus far, promising synthetic methods have enabled various designs and preparations of semiconductor-based nanostructure which have shown superior activity. This review summarized various synthetic routines toward carbon sphere template derived hollow nanostructures and their successful attempts in synthesize doping, solid solution, heterostructure, and surface modified nanostructures for heterogeneous photocatalysis and gas sensing. Moreover, the challenges and future prospects are briefly discussed. It is eagerly anticipated that this review may broaden the view and in-depth understanding of carbon sphere template derived hollow nanostructures while expected to have further progresses in heterogeneous photocatalysis, gas sensing and other related fields which will make great contributions to their application.
RÉSUMÉ
BACKGROUND: According to Compendium of Materia Medica, Gastrodia elata (GE) Blume as a top grade and frequently prescribed herbal medicine has been used in treating dizziness, headaches, and epilepsy, indicating a neuroprotective effect. Because GE is capable of suppressing a hyperactive liver and thus calming endogenous wind, and because Huntington's disease (HD) can be classified as a phenomenon of disturbed liver wind, it is suggested that GE might be beneficial in treating HD. However, although current studies support GE for the prevention of diverse neurodegenerations such as HD, its detailed mechanisms remain elusive. PURPOSE: To investigate the molecular mechanism of GE in preventing HD by focusing on mitochondrial morphology, which is highly associated with HD etiology and thus proposed as a therapeutic target of neurodegenerations. STUDY DESIGN/METHODS: The overexpression of the mutant huntingtin (mHTT) gene in rat pheochromocytoma (PC12) cells was used as an in vitro cell model of HD. A filter retardation assay was applied to measure protein aggregations during HTT expression. Cotransfection with mitochondrial fusion and fission genes was used to test their relationships with HTT aggregates by monitoring with a confocal laser scanning microscope and filter retardation assay. Western blot analysis was used to estimate protein expression under different drug treatments or cotransfections with other related genes. RESULTS: The overexpression of mutant but not normal HTT genes significantly resulted in protein aggregations in PC12 cells. GE dose-dependently attenuated mHTT-induced protein aggregations and free radical formations. GE significantly reversed mHTT-induced mitochondrial fragmentation and dysregulation of mitochondrial fusion and fission molecules. The overexpression of mitochondrial fusion genes attenuated mHTT-induced protein aggregations. Further, Mdivi-1, a DRP1 fission molecule inhibitor, significantly reversed mHTT-induced protein aggregations and mitochondrial fragmentation. CONCLUSION: GE attenuated mHTT aggregations through the control of mitochondrial fusion and the fission pathway.
Sujet(s)
Gastrodia , Protéine huntingtine/métabolisme , Maladie de Huntington/métabolisme , Mitochondries/effets des médicaments et des substances chimiques , Extraits de plantes/pharmacologie , Agrégats de protéines/effets des médicaments et des substances chimiques , Animaux , Protéine huntingtine/génétique , Maladie de Huntington/traitement médicamenteux , Mitochondries/métabolisme , Mutation , Cellules PC12 , Phytothérapie , Extraits de plantes/usage thérapeutique , RatsRÉSUMÉ
Paraquat (PQ) as an herbicide has been demonstrated to impair dopaminergic (DAergic) neurons and highly correlate with the etiology of Parkinson's disease (PD). WNT/ß-CATENIN signaling is known for the specification and neurogenesis of midbrain DAergic neurons and implicated as a therapeutic target in treating many diseases, such as cancer and degenerative diseases. LGK974, a WNT pathway inhibitor, is currently under clinical trial for patients with malignancies. Since the exact role of WNT/ß-CATENIN signaling in mediating PD is undetermined, LGK974 was used to examine its effect on the PQ-induced cell model of PD. LGK974 attenuated PQ-induced apoptosis and released mitochondrial pro-poptotic molecules in human neuroblastoma SH-SY5Y cell. PQ increased the levels of ß-CATENIN, non-phosphorylated (Ser33/37/Thr41) ß-CATENIN, and phosphorylated glycogen synthase kinase (GSK)-3α/ß. PQ also increased the nuclear translocation of ß-CATENIN, which can be attenuated by LKG974. Furthermore, LGK974 attenuated the PQ-induced release of mitochondrial proapoptotic factors and WNT agonist 1-induced cell death. Taken together, we have shown for the first time that LGK974 mediated through the WNT/ß-CATENIN pathway to prevent PQ-induced cell death.
Sujet(s)
Antinéoplasiques/pharmacologie , Survie cellulaire/effets des médicaments et des substances chimiques , Maladie de Parkinson/anatomopathologie , Pyrazines/pharmacologie , Pyridines/pharmacologie , Voie de signalisation Wnt/effets des médicaments et des substances chimiques , Apoptose/effets des médicaments et des substances chimiques , Protéines régulatrices de l'apoptose/métabolisme , Lignée cellulaire , Lignée cellulaire tumorale , Glycogen Synthase Kinase 3/biosynthèse , Humains , Immunohistochimie , Paraquat/antagonistes et inhibiteurs , Paraquat/toxicité , bêta-Caténine/biosynthèseRÉSUMÉ
Liu Jun Zi Tang (LJZT) has been used to treat functional dyspepsia and depression, suggesting its effects on gastrointestinal and neurological functions. LJZT is currently used as a complementary therapy to attenuate cisplatin-induced side effects, such as dyspepsia. However, its effect on chemotherapy-induced neuropathic pain or neurotoxicity has rarely been studied. Thus, we explored potential mechanisms underlying LJZT protection against cisplatin-induced neurotoxicity. We observed that LJZT attenuated cisplatin-induced thermal hyperalgesia in mice and apoptosis in human neuroblastoma SH-SY5Y cells. Furthermore, it also attenuated cisplatin-induced cytosolic and mitochondrial free radical formation, reversed the cisplatin-induced decrease in mitochondrial membrane potential, and increased the release of mitochondrial pro-apoptotic factors. LJZT not only activated the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) promoter region, but also attenuated the cisplatin-induced reduction of PGC-1α expression. Silencing of the PGC-1α gene counteracted the protection of LJZT. Taken together, LJZT mediated, through anti-oxidative effect and mitochondrial function regulation, to prevent cisplatin-induced neurotoxicity.
Sujet(s)
Médicaments issus de plantes chinoises/usage thérapeutique , Animaux , Apoptose/effets des médicaments et des substances chimiques , Lignée cellulaire tumorale , Cisplatine/toxicité , Humains , Hyperalgésie/induit chimiquement , Hyperalgésie/traitement médicamenteux , Potentiel de membrane mitochondriale/effets des médicaments et des substances chimiques , Souris , Syndromes neurotoxiques , Coactivateur 1-alpha du récepteur gamma activé par les proliférateurs de peroxysomes/métabolismeRÉSUMÉ
BACKGROUND: According to the Compendium of Materia Medica, Gastrodia elata (GE) Blume is a top-grade herbal medicine frequently used to treat dizziness, headaches, tetanus, and epilepsy, suggesting that it affects neurological functions. Although studies have supported its effects in preventing diverse neurodegenerations such as Huntington's disease (HD), its mechanisms require further investigation. PURPOSE: To investigate the ability of the molecular mechanism of GE to prevent mutant huntingtin (mHTT) protein aggregation by focusing on mitochondrial function and biogenesis, which have been proposed as the therapeutic targets of HD. STUDY DESIGN/METHODS: mHtt overexpression in pheochromocytoma (PC12) cells was used as an in vitro cell model of HD. A retardation assay was applied to measure protein aggregation during Htt expression. Cotransfection with transcriptional genes was used to test their relationships with HTT aggregates by monitoring with a confocal laser scanning microscope. Western blot analysis was used to estimate protein expression under different drug treatments or when cotransfected with other related genes. RESULTS: Mutant, abnormal Htt overexpression resulted in significant protein aggregation in PC12 cells. GE dose-dependently attenuated mHTT aggregates and increased cyclic-AMP response element-binding protein (CREB) phosphorylation. Adenosine A2A-R receptor (A2A-R) antagonist counteracted these phenomena. CREB overexpression significantly attenuated mHTT aggregation. GE increased the promoter activity and expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). Furthermore, wild-type PGC-1α but not mutant PGC-1α overexpression attenuated mHTT aggregates. CONCLUSION: GE attenuated mHtt aggregation by mediating mitochondrial function and biogenesis through the A2A-R/PKA/CREB/PGC-1α-dependent pathway.
Sujet(s)
Médicaments issus de plantes chinoises/pharmacologie , Gastrodia/composition chimique , Protéine huntingtine/génétique , Mitochondries/effets des médicaments et des substances chimiques , Antagonistes des récepteurs A2 à l'adénosine/pharmacologie , Animaux , Protéine de liaison à l'élément de réponse à l'AMP cyclique/métabolisme , Médicaments issus de plantes chinoises/administration et posologie , Humains , Protéine huntingtine/métabolisme , Maladie de Huntington/traitement médicamenteux , Maladie de Huntington/génétique , Mitochondries/métabolisme , Neuroprotecteurs/pharmacologie , Cellules PC12 , Coactivateur 1-alpha du récepteur gamma activé par les proliférateurs de peroxysomes/génétique , Coactivateur 1-alpha du récepteur gamma activé par les proliférateurs de peroxysomes/métabolisme , Phosphorylation/effets des médicaments et des substances chimiques , Régions promotrices (génétique) , RatsRÉSUMÉ
Rnf112 is a member of the RING finger protein family. The expression of Rnf112 is abundant in the brain and is regulated during brain development. Our previous study has revealed that Rnf112 can promote neuronal differentiation by inhibiting the progression of the cell cycle in cell models. In this study, we further revealed the important functions of Rnf112 in embryo development and in adult brain. Our data showed that most of the Rnf112 -/- embryos exhibited blood vascular defects and died in utero. Upon further investigation, we found that the survival rate of homozygous Rnf112 knockout mice in 129/sv and C57BL/6 mixed genetic background was increased. The survived newborns of Rnf112 -/- mice manifested growth retardation as indicated by smaller size and a reduced weight. Although the overall organization of the brain did not appear to be severely affected in Rnf112 -/- mice, using in vivo 3D MRI imaging, we found that when compared to wild-type littermates, brains of Rnf112 -/- mice were smaller. In addition, Rnf112 -/- mice displayed impairment of brain functions including motor balance, and spatial learning and memory. Our results provide important aspects for the study of Rnf112 gene functions.
Sujet(s)
Comportement animal/physiologie , Encéphale/vascularisation , Encéphale/embryologie , Protéines de liaison à l'ADN/métabolisme , Animaux , Protéines de liaison à l'ADN/génétique , Imagerie tridimensionnelle/méthodes , Apprentissage/physiologie , Mémoire/physiologie , Souris , Souris de lignée C57BL , Souris knockoutRÉSUMÉ
The extremely poor prognosis of patients with symptomatic hepatocellular carcinoma (HCC) diagnosed clinically at advanced stages suggests an urgent need for biomarkers that can be used for prospective surveillance and pre-clinical screening for early presence of pre-malignant lesions and tumors. In a retrospective longitudinal phase 3 biomarker study in seven medical centers of China, time-series and 6 months interval-serum samples were collected from chronic hepatitis B virus infected (CHB) patient cohorts at the pre-malignant or pre-clinical stages (average 6 months prior to clinical diagnosis) and CHB patients that did not develop cancer, and circulating miRNAs measured. A set of serum miRNAs including miR-193a-3p, miR-369-5p, miR-672, miR-429 and let-7i* were identified in pre-clinical HCC patients and have the potential to screen for CHB patients at high risk to develop HCC 6-12 months after miRNAs measurement. These circulating miRNAs combined with the conventional screening tools using α-fetoprotein and ultrasound, may have great promise for the prediction and prevention of HCC in high-risk populations.
Sujet(s)
Marqueurs biologiques tumoraux/sang , Carcinome hépatocellulaire/diagnostic , Tumeurs du foie/diagnostic , microARN/sang , Carcinome hépatocellulaire/sang , Carcinome hépatocellulaire/génétique , Hépatite B chronique/complications , Humains , Tumeurs du foie/sang , Tumeurs du foie/génétique , Courbe ROC , Alphafoetoprotéines/analyseRÉSUMÉ
Paraquat (PQ) as a Parkinsonian mimetic has been demonstrated to impair dopaminergic (DAergic) neurons and is highly correlated with the etiology of Parkinson's disease (PD) where the death of DAergic neurons has been mainly attributed to impaired mitochondrial functioning. In this study, PQ-induced cytotoxicity focusing on mitochondrial membrane permeability (MMP), which has been implicated to play a part in neurodegeneration, was investigated. Primarily, PQ-induced cytotoxicity and reactive oxygen species (ROS) were inhibited by an inhibitor of NADPH oxidase (NOX), indicating the toxic effect of PQ redox cycling. Further, dibucaine and cyclosporin A which respectively inhibit mitochondrial apoptosis-induced channels (MAC) and mitochondrial permeability transition pores (mPTP) were used and found to prevent PQ-induced mitochondrial dysfunction, such as decreased mitochondrial membrane potential and increased MMP, mitochondrial ROS, and pro-apoptotic factor release. Knockdown of bax and/or bak blocked PQ-induced mitochondrial clusterization of Bax and/or Bak and cytotoxicity, demonstrating the significance of MAC which is composed of Bax and/or Bak. This clusterization coincided with the release of mitochondrial apoptotic factors before there was an increase in inner MMP, indicating that MAC may precede mPTP formation. Besides, NOX inhibitor but not dibucaine attenuated the earlier PQ-induced cytosolic ROS formation or Bax and/or Bak clusterization indicating PQ redox cycling may account for MAC formation. In this model, we have resolved for the first that PQ cytotoxicity through redox cycling may sequentially result in increased outer (MAC) and inner (mPTP) MMP and suggested MMP could be implicated as a therapeutic target in treating neurodegenerative diseases like PD.
Sujet(s)
Membranes mitochondriales/métabolisme , Paraquat/toxicité , Animaux , Protéines régulatrices de l'apoptose/métabolisme , Comportement animal , Mort cellulaire/effets des médicaments et des substances chimiques , Ciclosporine/pharmacologie , Cinchocaïne/pharmacologie , Extinction de l'expression des gènes/effets des médicaments et des substances chimiques , Mâle , Potentiel de membrane mitochondriale/effets des médicaments et des substances chimiques , Mitochondries/effets des médicaments et des substances chimiques , Mitochondries/métabolisme , Protéines de transport de la membrane mitochondriale/métabolisme , Pore de transition de perméabilité mitochondriale , Composés onium/pharmacologie , Cellules PC12 , Perméabilité/effets des médicaments et des substances chimiques , Multimérisation de protéines , Rats , Rat Sprague-Dawley , Espèces réactives de l'oxygène/métabolisme , Protéine Bak/métabolisme , Protéine Bax/métabolismeRÉSUMÉ
Activating transcription factor-(ATF-) 3, a stress-inducible transcription factor, is rapidly upregulated under various stress conditions and plays an important role in inducing cancer cell apoptosis. NBM-TP-007-GS-002 (GS-002) is a Taiwanese propolin G (PPG) derivative. In this study, we examined the antitumor effects of GS-002 in human hepatoma Hep3B and HepG2 cells in vitro. First, we found that GS-002 significantly inhibited cell proliferation and induced cell apoptosis in dose-dependent manners. Several main apoptotic indicators were found in GS-002-treated cells, such as the cleaved forms of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP). GS-002 also induced endoplasmic reticular (ER) stress as evidenced by increases in ER stress-responsive proteins including glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153), phosphorylated eukaryotic initiation factor 2 α (eIF2 α ), phosphorylated protein endoplasmic-reticular-resident kinase (PERK), and ATF-3. The induction of ATF-3 expression was mediated by mitogen-activated protein kinase (MAPK) signaling pathways in GS-002-treated cells. Furthermore, we found that GS-002 induced more cell apoptosis in ATF-3-overexpressing cells. These results suggest that the induction of apoptosis by the propolis derivative, GS-002, is partially mediated through ER stress and ATF-3-dependent pathways, and GS-002 has the potential for development as an antitumor drug.
RÉSUMÉ
NBM-T-L-BMX-OS01 (BMX) was derived from the semisynthesis of osthole, isolated from Cnidium monnieri (L.) Cuss., and was identified to be a potent inhibitor of HDAC8. This study shows that HDAC8 is highly expressed in the pancreas and the brain. The function of HDAC8 in the brain has not been adequately studied. Because BMX enhances neurite outgrowth and cAMP response element-binding protein (CREB) activation, the effect of BMX on neural plasticity such as learning and memory is examined. To examine declarative and nondeclarative memory, a water maze, a passive one-way avoidance task, and a novel object recognition task were performed. Results from the water maze revealed that BMX and suberoylanilide-hydroxamic-acid-(SAHA-) treated rats showed shorter escape latency in finding the hidden platform. The BMX-treated animals spent more time in the target quadrant in the probe trial performance. An analysis of the passive one-way avoidance results showed that the BMX-treated animals stayed longer in the illuminated chamber by 1 day and 7 days after footshock. The novel object recognition task revealed that the BMX-treated animals showed a marked increase in the time spent exploring novel objects. Furthermore, BMX ameliorates scopolamine-(Sco-) induced learning and memory impairment in animals, indicating a novel role of BMX in learning and memory.