RESUMEN
Autophagy has been shown to maintain neural system homeostasis during stroke. However, the molecular mechanisms underlying neuronal autophagy in ischemic stroke remain poorly understood. This study aims to investigate the regulatory mechanisms of the pathway consisting of MEG3 (maternally expressed gene 3), microRNA-378 (miR-378), and GRB2 (growth factor receptor-bound protein 2) in neuronal autophagy and neurological functional impairment in ischemic stroke. A mouse model of the middle cerebral artery occluded-induced ischemic stroke and an in vitro model of oxygen-glucose deprivation-induced neuronal injury were developed. To understand the role of the MEG3/miR-378/GRB2 axis in the neuronal regulation, the expression of proteins associated with autophagy in neurons was measured by Western blotting analysis, and neuron death was evaluated using a lactate dehydrogenase leakage rate test. First, it was found that the GRB2 gene, up-regulated in middle cerebral artery occluded-operated mice and oxygen-glucose deprivation-exposed neurons, was a target gene of miR-378. Next, miR-378 inhibited neuronal loss and neurological functional impairment in mice, as well as neuronal autophagy and neuronal death by silencing of GRB2. Confirmatory in vitro experiments showed that MEG3 could specifically bind to miR-378 and subsequently up-regulate the expression of GRB2, which in turn suppressed the activation of Akt/mTOR pathway. Taken together, these findings suggested that miR-378 might protect against neuronal autophagy and neurological functional impairment and proposed that a MEG3/miR-378/GRB2 regulatory axis contributed to better understanding of the pathophysiology of ischemic stroke.
Asunto(s)
Autofagia , Isquemia Encefálica/metabolismo , Proteína Adaptadora GRB2/metabolismo , MicroARNs/metabolismo , Neuronas/metabolismo , ARN Largo no Codificante/metabolismo , Transducción de Señal , Accidente Cerebrovascular/metabolismo , Animales , Isquemia Encefálica/genética , Isquemia Encefálica/patología , Modelos Animales de Enfermedad , Proteína Adaptadora GRB2/genética , Humanos , Ratones , Ratones Mutantes , MicroARNs/genética , Neuronas/patología , ARN Largo no Codificante/genética , Accidente Cerebrovascular/genética , Accidente Cerebrovascular/patologíaRESUMEN
BACKGROUND: At present, the relationship between serum homocysteine and microalbuminuria (MAU) in systemic lupus erythematosus (SLE) patients is still unclear. Therefore, the aim of our study was to analyze the association between serum homocysteine and MAU in SLE patients. METHODS: The study analyzed 150 patients with SLE at Affiliated Hospital of Youjiang Medical University for Nationalities retrospectively, and we collected for clinical and laboratory data. RESULTS: We found a positive correlation between serum homocysteine and MAU in SLE patients (r = 0.430, p < 0.001). We found that serum homocysteine levels were increased in SLE patients with MAU positive compared to those who were MAU negative (p < 0.001). After adjusting for multiple confounding factors, we found that serum homocysteine maintained a positive correlation with MAU in patients with SLE in multivariate correlation analysis (p = 0.253, r = 0.002). The receiver operating characteristic (ROC) curve with an area under the curve of 0.730, and serum homocysteine had 72.2% sensitivity and 61.9% specificity with cutoff values 9.0 to identify the SLE patients with MAU positive. CONCLUSIONS: The current results found a correlation between serum homocysteine and MAU in SLE patients, suggesting that elevated serum homocysteine levels might be an adverse factor for SLE patients with kidney injury.
Asunto(s)
Lupus Eritematoso Sistémico , Albuminuria/diagnóstico , Homocisteína , Humanos , Lupus Eritematoso Sistémico/complicaciones , Lupus Eritematoso Sistémico/diagnóstico , Curva ROC , Estudios RetrospectivosRESUMEN
The active lone pair electron effect and highly flexible coordination geometry of Pb2+ prevented the rational construction of metal-organic frameworks (MOFs) but promoted excellent fluorescence tuning. The regulation on organic and alkali templates facilitated the assemblies of three new Pb-MOFs: [Pb2(pia)2(DMA)]·DMA (1), [Pb2(pia)2(DMF)]·1.5DMF (2), and [Pb2(pia)2(DMF)]·NEt3 (3). They were rigid rod-spacer and double-walls frameworks, which possess defective dicubane [Pb4O6] based metal-carboxyl chains constructed from both semidirected and holodirected Pb2+ ions. These MOFs exhibited thermal stability up to 370 °C and unprecedented chemical stability in H2O and acidic (pH 2) and alkaline (pH 12) aqueous solutions, found for the first time in Pb-MOFs. A single-phase and rare-earth-free white-emitting phosphor, 1, was screen out, which showed a near-sunlight and human-vision-friendly broadband spectrum covering the full visible region, possessing the close-to-pure-white chromaticity coordinates of (0.332, 0.347), a near-daylight color temperature of 5696 K, and a high color rendering index of 95. The replacement of DMF as apical ligand and guest in 2 resulted in an intrinsic single and narrow emission at 562 nm with yellow color. The convenient yellow-and-blue color-tuning until white for 2 was realized by either solution or solid blending with blue-emissive H2pia, benefited from their highly matched excitation spectra. Using large NEt3 as template guest induced great framework distortion for 3 and led to white emission with chromaticity coordinates of (0.302, 0.294), stemming from nonequivalent dual emission at 450 and 545 nm. In-depth structure analysis revealed intra-/interchain Pb···Pb interactions in the lead(II)-carboxyl chains greatly affected the photochemical output.
RESUMEN
Tartary buckwheat (Fagopyrum tataricum Gaertn.) contains high concentrations of flavonoids. The flavonoids are mainly represented by rutin, anthocyanins and proanthocyanins in tartary buckwheat. R2R3-type MYB transcription factors (TFs) play key roles in the transcriptional regulation of the flavonoid biosynthetic pathway. In this study, two TF genes, FtMYB1 and FtMYB2, were isolated from F. tataricum and characterized. The results of bioinformatic analysis indicated that the putative FtMYB1 and FtMYB2 proteins belonged to the R2R3-MYB family and displayed a high degree of similarity with TaMYB14 and AtMYB123/TT2. In vitro and in vivo evidence both showed the two proteins were located in the nucleus and exhibited transcriptional activation activities. During florescence, both FtMYB1 and FtMYB2 were more highly expressed in the flowers than any other organ. The overexpression of FtMYB1 and FtMYB2 significantly enhanced the accumulation of proanthocyanidins (PAs) and showed a strong effect on the target genes' expression in Nicotiana tabacum. The expression of dihydroflavonol-4-reductase (DFR) was upregulated to 5.6-fold higher than that of control, and the expression level was lower for flavonol synthase (FLS). To our knowledge, this is the first functional characterization of two MYB TFs from F. tataricum that control the PA pathway.
Asunto(s)
Fagopyrum/genética , Regulación de la Expresión Génica de las Plantas , Proantocianidinas/metabolismo , Factores de Transcripción/genética , Oxidorreductasas de Alcohol/genética , Secuencia de Aminoácidos , Antocianinas/metabolismo , Proteínas de Arabidopsis/genética , Secuencia de Bases , Biología Computacional , Fagopyrum/metabolismo , Flavonoides/metabolismo , Expresión Génica , Genes Reporteros , Datos de Secuencia Molecular , Oxidorreductasas/genética , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente , Alineación de Secuencia , Nicotiana/genética , Nicotiana/metabolismo , Factores de Transcripción/metabolismo , Activación TranscripcionalRESUMEN
OBJECTIVE: To clone the cDNA sequence of squalene synthase gene from Paris polyphylla, and characterize the biological features of the obtained SQS. METHOD: Using homology cloning and RACE technique, a full-length cDNA sequence of PpSQS gene was isolated from P. polyphylla. The obtained sequence was analyzed by bioinformatics softwares. A plasmid [named pET-30b (+)-PpSQS] was constructed for prokaryotic expression the recombinant PpSQS. RESULT: The full-length cDNA of PpSQS gene is 1 498 bp, which contains a 1 212 bp ORF. Sequence analysis indicated that PpSQS encoded 403 amino acids residues with a calculated molecular weight (MW) of 46.36 kDa and an isoelectric point (pI) of 6.83. SDS-PAGE results showed that the recombinant PpSQS was expressed in Escherichia coli BL21 (DE3) by inducing with 1 mmol x L(-1) IPTG. CONCLUSION: The full-length cDNA sequence of PpSQS gene was obtained from P. polyphylla, and its molecular features were consisted with classic SQS in plant. The recombinant PpSQS was successfully expressed in E. coli.
Asunto(s)
Escherichia coli/genética , Farnesil Difosfato Farnesil Transferasa/genética , Liliaceae/enzimología , Clonación Molecular , Filogenia , Proteínas Recombinantes/biosíntesisRESUMEN
A regio- and stereoselective iodolactonization of internal electron-deficient olefinic acids has been reported, which provides a straightforward access to a series of multi-functionalized seven-membered lactones containing two consecutive chiral centers. The ester substituents on the olefins played a key role in achieving high regioselectivity. This result was proved through experiments and DFT calculations.
RESUMEN
Biphenylcarboxylic acid with two competing C(sp2)-H sites was designed for site selective C(sp2)-H functionalization by developing carboxylic acids assisted remote and selective olefination via 7-membered palladacycle. Mechanism investigation and DFT calculations reveal a kinetics-determined process, which could be utilized to explore a variety of remote site selectivity. The practicability of this method was highlighted by the precise construction of phenathrene under sequential site selectivity.
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Ru(II)-catalyzed direct alkylation of tertiary phosphines via hydroarylation of activated olefins promoted by mono-N-protected amino acid (MPAA) was achieved. This protocol provides a straightforward access to a large library of Buchwald-type bulky alkylated monophosphines from commercially available biaryl phosphine. Moreover, two ruthenacycle intermediates of tertiary phosphines via C-H bond cleavage were isolated to illustrate the mechanism of P(III)-directed C-H activation.
RESUMEN
A general protocol for site-preferential mono-C-H arylation of tertiary phosphine ligands catalyzed by a ruthenium(II) complex was devised. This protocol gives access to a series of modified Buchwald-biaryl monophosphines on a gram scale in moderate to excellent yields. A catalytic cycle is proposed derived from knowledge of the intermediates observed by ESI-MS. Importantly, these monoarylated products could be further transformed into dibenzophosphole derivatives.
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A weakly carboxylate-directed palladium(II)-catalyzed ortho-C-H alkynylation of diverse phenylacetic acids promoted by monoprotected amino acid ligand enabled is reported. The reaction has a broad substrate scope including α-secondary, tertiary, and quaternary phenylacetic acids. Notably, the direct ortho-C-H alkynylation of α-quaternary phenylacetic acids and chiral α-tertiary phenylacetic acids was achieved for the first time. Moreover, this method could be used for simple and efficient gram-scale synthesis and diversification of an anti-inflammatory drug.
RESUMEN
Anthocyanins confer the red color in the hypocotyl of tartary buckwheat sprouts. Uridine diphosphate (UDP)-glucose:flavonoid 3-O-glycosyltransferase (UFGT) stabilizes anthocyanin by attaching the glucosyl moiety from UDP-glucose to the C3 hydroxyl of anthocyanin. In this study, we characterized three UFGT-like genes, designated FtUFGT1, 2, and 3 from tartary buckwheat. The results revealed that FtUFGT1, FtUFGT2, and FtUFGT3 can convert cyanidin to cyanidin 3-O-glucoside, with specific activities of 20.01 × 10(-3), 8.93 × 10(-3), and 20.24 × 10(-3) IU/mg, respectively. The active-site residues of the C-terminal domains and the N-terminal domains are important for the donor and acceptor recognition of these proteins. The expression of the three FtUFGTs paralleled the tissue-specific anthocyanin accumulation. After cold treatment, the increased content of anthocyanin was accompanied by the up-regulated expression of the three FtUFGTs. Among these three UGFT gene members, FtUFGT3 showed the highest expression level and the highest specific activity, suggesting that FtUFGT3 might be the major gene involved in anthocyanin biosynthesis. These results suggested that the FtUFGT genes, FtUFGT3 in particular, might be important candidates for anthocyanin formation in tartary buckwheat sprouts.