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Mast cells (MCs) are an important treatment target for high-affinity IgE Fc receptor (FcεRI)-mediated allergic diseases. The plant-derived molecule 4-methylumbelliferone (4-MU) has beneficial effects in animal models of inflammation and autoimmunity diseases. The aim of this study was to examine 4-MU effects on MC activation and probe the underlying molecular mechanism(s). We sensitized rat basophilic leukemia cells (RBLs) and mouse bone marrow-derived mast cells (BMMCs) with anti-dinitrophenol (DNP) immunoglobulin (Ig)E antibodies, stimulated them with exposure to DNP-human serum albumin (HSA), and then treated stimulated cells with 4-MU. Signaling-protein expression was determined by immunoblotting. In vivo allergic responses were examined in IgE-mediated passive cutaneous anaphylaxis (PCA) and ovalbumin (OVA)-induced active systemic anaphylaxis (ASA) mouse models. 4-MU inhibited ß-hexosaminidase activity and histamine release dose-dependently in FcεRI-activated RBLs and BMMCs. Additionally, 4-MU reduced cytomorphological elongation and F-actin reorganization while down-regulating IgE/Ag-induced phosphorylation of SYK, NF-κB p65, ERK1/2, p38, and JNK. Moreover, 4-MU attenuated the PCA allergic reaction (i.e., less ear thickening and dye extravasation). Similarly, we found that 4-MU decreased body temperature, serum histamine, and IL4 secretion in OVA-challenged ASA model mice. In conclusion, 4-MU had a suppressing effect on MC activation both in vitro and in vivo and thus may represent a new strategy for treating IgE-mediated allergic conditions.
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Receptores de IgERESUMEN
The treatment of environmental pollutants such as synthetic dyes and lignin has received much attention, especially for biotechnological treatments using both native and artificial metalloenzymes. In this study, we designed and engineered an efficient peroxidase using the O2 carrier myoglobin (Mb) as a protein scaffold by four mutations (F43Y/T67R/P88W/F138W), which combines the key structural features of natural peroxidases such as the presence of a conserved His-Arg pair and Tyr/Trp residues close to the heme active center. Kinetic studies revealed that the quadruple mutant exhibits considerably enhanced peroxidase activity, with the catalytic efficiency (kcat/Km) comparable to that of the most efficient natural enzyme, horseradish peroxidase (HRP). Moreover, the designed enzyme can effectively decolorize a variety of synthetic organic dyes and catalyze the bioconversion of lignin, such as Kraft lignin and a model compound, guaiacylglycerol-ß-guaiacyl ether (GGE). As analyzed by HPLC and ESI-MS, we identified several bioconversion products of GGE, as produced via bond cleavage followed by dimerization or trimerization, which illustrates the mechanism for lignin bioconversion. This study indicates that the designed enzyme could be exploited for the decolorization of textile wastewater contaminated with various dyes, as well as for the bioconversion of lignin to produce more value-added products.
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Colorantes/química , Lignina/metabolismo , Mioglobina/química , Peroxidasa/metabolismo , Ingeniería de Proteínas , Animales , Cromatografía Líquida de Alta Presión , Color , Guaifenesina/análogos & derivados , Hemo/química , Peróxido de Hidrógeno/metabolismo , Cinética , Oxidación-Reducción , Polimerizacion , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Ultravioleta , CachaloteRESUMEN
BACKGROUND: Taste is fundamental to diet selection in vertebrates. Genetic basis of sweet taste receptor in the shaping of food habits has been extensively studied in mammals and birds, but scarcely studied in fishes. Grass carp is an excellent model for studying vegetarian adaptation, as it exhibits food habit transition from carnivory to herbivory. RESULTS: We identified six sweet taste receptors (gcT1R2A-F) in grass carp. The four gcT1R2s (gcT1R2C-F) have been suggested to be evolved from and paralogous to the two original gcT1R2s (gcT1R2A and gcT1R2B). All gcT1R2s were expressed in taste organs and mediated glucose-, fructose- or arginine-induced intracellular calcium signaling, revealing they were functional. In addition, grass carp was performed to prefer fructose to glucose under a behavioral experiment. Parallelly, compared with gcT1R2A-F/gcT1R3 co-transfected cells, gcT1R2C-F/gcT1R3 co-transfected cells showed a higher response to plant-specific fructose. Moreover, food habit transition from carnivory to herbivory in grass carp was accompanied by increased gene expression of certain gcT1R2s. CONCLUSIONS: We suggested that the gene expansion of T1R2s in grass carp was an adaptive strategy to accommodate the change in food environment. Moreover, the selected gene expression of gcT1R2s might drive the food habit transition from carnivory to herbivory in grass carp. This study provided some evolutional and physiological clues for the formation of herbivory in grass carp.
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Adaptación Biológica/genética , Carpas/genética , Herbivoria/genética , Receptores Acoplados a Proteínas G/genética , Gusto/genética , Aclimatación/genética , Animales , Carpas/clasificación , Carpas/fisiología , Conducta Alimentaria , Proteínas de Peces/genética , Amplificación de Genes/fisiología , Expresión Génica , Mamíferos/genética , Papilas Gustativas/metabolismoRESUMEN
Two homologous meroterpenoid gene clusters consisting of contiguous genes encoding polyketide synthase (PKS), prenyltransferase (PT), terpenoid cyclase (TC) and other tailoring enzymes were identified from two phylogenetically distinct fungi through computational analysis. Media optimization guided by reverse-transcription PCR (RT-PCR) enabled two strains to produce eight new and two known meroterpenoids (1-10). Using gene inactivation, heterologous expression, and biochemical analyses, we revealed a new polyketide-terpenoid assembly line that utilizes a pair of PKSs to synthesize 2,4-dihydroxy-6-alkylbenzoic acid, followed by oxidative decarboxylation, farnesyl transfer, and terpene cyclization to construct the meroterpenoid scaffold. In addition, two of the isolated meroterpenoids (3 and 17 d) showed immunosuppressive bioactivity. Our work reveals a new strategy for meroterpenoid natural products discovery, and reveals the biosynthetic pathway for compounds 1-10.
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Hongos/genética , Genoma Fúngico , Terpenos/metabolismo , Productos Biológicos/química , Productos Biológicos/metabolismo , Biología Computacional , Ciclización , Dimetilaliltranstransferasa/genética , Dimetilaliltranstransferasa/metabolismo , Hongos/clasificación , Familia de Multigenes , Filogenia , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo , Terpenos/químicaRESUMEN
OBJECTIVE: This study investigated the effect of fermented biogas residue (FBR) of wheat on the performance, serum biochemical parameters, and meat quality in pigs. METHODS: We selected 128 pigs (the mean initial body weight was 40.24±3.08 kg) and randomly allocated them to 4 groups (1 control group and 3 treatment groups) with 4 replicates per group and 8 pigs per pen in a randomized complete block design based on initial body weight and sex. The control group received a corn-soybean meal-based diet, the treatment group fed diets containing 5%, 10%, and 15% FBR, respectively (abbreviated as FBR5, FBR10, and FBR15, respectively). Every group received equivalent-energy and nitrogen diets. The test lasted 60 days and was divided into early and late stages. Blood and carcass samples were obtained on 60 d. Meat quality was collected from two pigs per pen. RESULTS: During the late stage, the average daily feed intake and average daily gain of the treatment groups was greater than that of the control group (p<0.05). During the entire experiment, the average daily gain of the treatment groups was higher than that of the control group (p<0.05). Fermented biomass residue did not significantly affect serum biochemical parameters or meat quality, but did affect amino acid profiles in pork. The contents of Asp, Arg, Tyr, Phe, Leu, Thr, Ser, Lys, Pro, Ala, essential amino acids, non-essential amino acids, and total amino acids in pork of FBR5 and FBR10 were greater than those of the control group (p<0.05). CONCLUSION: These combined results suggest that feeding FBR could increase the average daily gain and average daily feed intake in pigs and the content of several flavor-promoting amino acids.
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MiR-145 is downregulated and functions as a tumor suppressor in many malignancies. In this study, the biological function, molecular mechanism, and direct target genes of miR-145 in nasopharyngeal carcinoma (NPC) cells were investigated. Cell survival was detected by cell viability assay, and cell cycle was determined through flow cytometry. Invasion and migration of NPC cells were examined using cell invasion and wound healing assays, respectively. A disintegrin and metalloproteinase 17 (ADAM17) was verified as the target of miR-145 through luciferase reporter assay, qRT-PCR, and Western blot analysis. In NPC cell lines, miR-145 expression was significantly downregulated and ADAM17 protein expression was upregulated. ADAM17 was downregulated at the post-transcriptional level by miR-145 via the binding site of ADAM17-3'UTR. Transfection with miR-145 mimic suppressed cell growth and induced cell cycle arrest in the G0/G1 phase by upregulating key G0/G1 phase regulators, namely, p53 and p21. MiR-145 also inhibited cellular migration and invasion through targeting ADAM17 involving the regulation of EGFR and E-cadherin. Knockdown of ADAM17 elicited similar effects to that of miR-145 on NPC cells. This study reveals that miR-145 suppressed the invasion and migration of NPC cells by targeting ADAM17. Thus, miR-145 could be a therapeutic target for NPC.
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Proteínas ADAM/genética , Movimiento Celular/genética , MicroARNs/genética , Neoplasias Nasofaríngeas/genética , Invasividad Neoplásica/genética , Regiones no Traducidas 3'/genética , Proteína ADAM17 , Cadherinas/genética , Carcinoma , Línea Celular Tumoral , Regulación hacia Abajo/genética , Receptores ErbB/genética , Puntos de Control de la Fase G1 del Ciclo Celular/genética , Regulación Neoplásica de la Expresión Génica/genética , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/patología , Invasividad Neoplásica/patología , Procesamiento Postranscripcional del ARN/genética , Fase de Descanso del Ciclo Celular/genética , Regulación hacia Arriba/genéticaRESUMEN
Activation of inflammasomes involves multi-protein assembly and activation of inflammatory caspase and maturation of pro-inflammatory cytokines interleukin-1ß(IL-1ß) and interleukin-18(IL-18). Among those types of inflammasomes, NOD (nucleotide binding oligomerization domain)-like receptors(NLRP3) is the most studied inflammasome which involves in amount of human inflammatory and autoimmune diseases. Therefore, targeting on NLRP3 inflammasome has been one of the promising methods for treatment of diseases. In this review, we focused on the studies in the latest five years on the mechanisms of NLRP3 inflammasome regulation which mainly including NLRP3 priming, three protein complex assembly and regulation of NLRP3 inflammasome activation by endogenous metabolic compounds, iron flux, subcellular structure, other types of cells and small molecular compounds. Better understanding of NLRP3 inflammasome will be benefit for potential drug target and treatment of NLRP3 inflammasome-associated diseases.
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Inflamasomas/metabolismo , Inflamación/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Enfermedades Autoinmunes , Caspasas/metabolismo , Humanos , Interleucina-18/metabolismo , Interleucina-1beta/metabolismoRESUMEN
BACKGROUND: Epithelial-mesenchymal transition (EMT) is associated with invasion and metastasis of cancer cells. High-mobility group AT-hook 2 (HMGA2) has been found to play a critical role in EMT in a number of malignant tumors. However, whether HMGA2 regulates the EMT in human nasopharyngeal carcinoma (NPC) is unclear. OBJECTIVE: The aim of this study was to investigate the effect and mechanism of HMGA2 in inducing invasion and migration in NPC. METHODS: In NPC tissues samples, the association of HMGA2 mRNA expression with clinicopathological characteristics were estimated by real-time quantitative RT-PCR(qRT-PCR). In vitro, following the silencing of HMGA2 in CNE-1 and CNE-2 cell lines, the viability and metastatic ability were analyzed using Cell Counting Kit-8 (CCK8), colony formation assay, and transwell assay. EMT and transforming growth factor-beta (TGFß)/Smad3 signaling pathway-related protein expression changes were evaluated using western blot. RESULTS: HMGA2 was upregulated in NPC cell lines and clinical specimens (P < 0.01), and HMGA2 expression correlated significantly with metastasis (P = 0.02) and disease-free survival of NPC (hazard ratio: 3.52; 95% confidence interval: 1.34-7.79; P = 0.01). In addition, following in vitro knockdown of HMGA2, the aggressiveness of cells was markedly inhibited, Vimentin and Snail level was downregulated and E-cadherin expression was upregulated. Moreover, the expression of key proteins TGFßRII and p-Smad3 of the TGFß/Smad3 signaling pathway was inhibited by the downregulation of HMGA2. CONCLUSION: HMGA2 might maintain EMT-induced invasion and migration through the TGFß/Smad3 signaling pathway in NPC cell lines.
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Transición Epitelial-Mesenquimal , Regulación Neoplásica de la Expresión Génica , Proteína HMGA2/genética , Neoplasias Nasofaríngeas/genética , Neoplasias Nasofaríngeas/patología , Nasofaringe/patología , Invasividad Neoplásica/genética , Carcinoma , Línea Celular Tumoral , Movimiento Celular , Femenino , Proteína HMGA2/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Nasofaringe/metabolismo , Invasividad Neoplásica/patología , Interferencia de ARN , ARN Interferente Pequeño/genética , Transducción de Señal , Proteína smad3/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Regulación hacia ArribaRESUMEN
OBJECTIVES: The purpose of this study was to investigate the relationship between huntingtin-associated protein1 (HAP1) gene and radiation therapy of breast cancer cells. METHODS: HAP1 gene was transfected into breast cancer MCF-7 cells, which was confirmed by quantitative reverse transcription-polymerase chain reaction analysis (qRT-PCR) and Western blot in vitro. The changes of cell radiosensitivity were assessed by colony formation assay. Apoptosis were examined by flow cytometry. The expressions of two radiation-induced genes were evaluated by Western blot. Tumor growth was investigated in nude mice xenograft models in vivo. RESULTS: Our data showed that HAP1 gene expression was significantly increased in HAP1-transfected MCF-7 cells in comparison with the parental cells or negative control cells. The survival rate in MCF-7/HAP1 cells was significantly decreased after irradiation (0, 2, 4, 6, 8Gy), compared to cells in MCF-7 and MCF-7/Pb groups in vitro. HAP1 gene increased apoptosis in MCF-7 cells after irradiation. Additionally, the tumor volume and weight in MCF-7/HAP1+RT group were observably lower than in MCF-7/HAP1 group and MCF-7/Pb+RT group. CONCLUSION: The present study indicated that HAP1 gene expression was related to the radiosensitivity of breast cancer cells and may play an important role in the regulation of cellular radiosensitivity.
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Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/radioterapia , Regulación Neoplásica de la Expresión Génica , Proteínas del Tejido Nervioso/metabolismo , Animales , Apoptosis , Femenino , Citometría de Flujo , Humanos , Células MCF-7 , Ratones , Ratones Desnudos , Trasplante de Neoplasias , Proteínas del Tejido Nervioso/genética , Tolerancia a Radiación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células MadreRESUMEN
Inflammatory bowel disease (IBD) affects millions of people worldwide. Although the etiology of this disease is uncertain, accumulating evidence indicates a key role for the activated mucosal immune system. In the present study, we examined the effects of the natural compound fraxinellone on dextran sulfate sodium (DSS)-induced colitis in mice, an animal model that mimics IBD. Treatment with fraxinellone significantly reduced weight loss and diarrhea in mice and alleviated the macroscopic and microscopic signs of the disease. In addition, the activities of myeloperoxidase and alkaline phosphatase were markedly suppressed, while the levels of glutathione were increased in colitis tissues following fraxinellone treatment. This compound also decreased the colonic levels of interleukin (IL)-1ß, IL-6, IL-18 and tumor necrosis factor (TNF)-α in a concentration-dependent manner. These effects of fraxinellone in mice with experimental colitis were attributed to its inhibition of CD11b(+) macrophage infiltration. The mRNA levels of macrophage-related molecules in the colon, including intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX2), were also markedly inhibited following fraxinellone treatment. The results from in vitro assays showed that fraxinellone significantly reduced lipopolysaccharide (LPS)-induced production of nitric oxide (NO), IL-1ß and IL-18 as well as the activity of iNOS in both THP-1 cells and mouse primary peritoneal macrophages. The mechanisms responsible for these effects were attributed to the inhibitory role of fraxinellone in NF-κB signaling and NLRP3 inflammasome activation. Overall, our results support fraxinellone as a novel drug candidate in the treatment of colonic inflammation.
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Benzofuranos/farmacología , Colitis/metabolismo , Modelos Animales de Enfermedad , Macrófagos Peritoneales/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Proteína con Dominio Pirina 3 de la Familia NLR/antagonistas & inhibidores , Animales , Benzofuranos/uso terapéutico , Línea Celular , Colitis/inducido químicamente , Colitis/tratamiento farmacológico , Sulfato de Dextran/toxicidad , Relación Dosis-Respuesta a Droga , Humanos , Inflamasomas/antagonistas & inhibidores , Inflamasomas/metabolismo , Macrófagos Peritoneales/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiologíaRESUMEN
In the present study, we aimed to investigate the immunosuppressive activity of vaticaffinol, a resveratrol tetramer isolated from Vatica mangachapoi, on T lymphocytes both in vitro and in vivo, and further explored its potential molecular mechanism. Resveratrol had a wide spectrum of healthy beneficial effects with multiple targets. Interestingly, its tetramer, vaticaffinol, exerted more intensive immunosuppressive activity than resveratrol. Vaticaffinol significantly inhibited T cells proliferation activated by concanavalin A (Con A) or anti-CD3 plus anti-CD28 in a dose- and time-dependent manner. It also induced Con A-activated T cells undergoing apoptosis through mitochondrial pathway. Moreover, this compound prevented cells from entering S phase and G2/M phase during T cells activation. In addition, vaticaffinol inhibited ERK and AKT signaling pathways in Con A-activated T cells. Furthermore, vaticaffinol significantly ameliorated ear swelling in a mouse model of picryl chloride-induced ear contact dermatitis in vivo. In most of the aforementioned experiments, however, resveratrol had only slight effects on the inhibition of T lymphocytes compared with vaticaffinol. Taken together, our findings suggest that vaticaffinol exerts more preferable immunosuppressive activity than its precursor resveratrol both in vitro and in vivo by affecting multiple targets against activated T cells.
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Inmunosupresores/farmacología , Activación de Linfocitos/efectos de los fármacos , Estilbenos/química , Estilbenos/farmacología , Linfocitos T/efectos de los fármacos , Animales , Apoptosis/efectos de los fármacos , Puntos de Control del Ciclo Celular/efectos de los fármacos , Dermatitis por Contacto/tratamiento farmacológico , Femenino , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C , ResveratrolRESUMEN
In the present paper, we aimed to examine the novel effects of cerebroside D, a glycoceramide compound, on murine experimental colitis. Cerebroside D significantly reduced the weight loss, mortality rate and alleviated the macroscopic and microscopic appearances of colitis induced by dexran sulfate sodium. This compound also decreased the levels of TNF-α, IFN-γ and IL-1ß in intestinal tissue of mice with experimental colitis in a concentration-dependent manner, accompanied with markedly increased serum level of IL-10. Cerebroside D inhibited proliferation and induced apoptosis of T cells activated by concanavalin A or anti-CD3 plus anti-CD28 antibodies. The compound did not show an effect on naive lymphocytes but prevented cells from entering S phase and G2/M phase during T cells activation. Moreover, the treatment of cerebroside D led to apoptosis of activated T cells with the cleavage of caspase 3, 9, 12 and PARP. These results showed multiple effects of cerebroside D against activated T cells for a novel approach to treatment of colonic inflammation.
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Apoptosis/efectos de los fármacos , Cerebrósidos/farmacología , Colitis/tratamiento farmacológico , Linfocitos T/efectos de los fármacos , Animales , Caspasas/metabolismo , Ciclo Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Cerebrósidos/administración & dosificación , Colitis/fisiopatología , Sulfato de Dextran/toxicidad , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Sistemas de Liberación de Medicamentos , Interferón gamma/efectos de los fármacos , Interferón gamma/metabolismo , Interleucina-10/sangre , Interleucina-1beta/efectos de los fármacos , Interleucina-1beta/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Poli(ADP-Ribosa) Polimerasas/metabolismo , Linfocitos T/metabolismo , Factor de Necrosis Tumoral alfa/efectos de los fármacos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Tetracyclines are a class of antibiotics that exhibited potent activity against a wide range of Gram-positive and Gram-negative bacteria, yet only five members were isolated from actinobacteria, with two of them approved as clinical drugs. In this work, we developed a genome mining strategy using a TetR/MarR-transporter, a pair of common resistance enzymes in tetracycline biosynthesis, as probes to find the potential tetracycline gene clusters in the actinobacteria genome database. Further refinement using the phylogenetic analysis of chain length factors resulted in the discovery of 25 distinct tetracycline gene clusters, which finally resulted in the isolation and characterization of a novel tetracycline, hainancycline (1). Through genetic and biochemical studies, we elucidated the biosynthetic pathway of 1, which involves a complex glycosylation process. Our work discloses nature's huge capacity to generate diverse tetracyclines and expands the chemical diversity of tetracyclines.
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This research focused on a novel 7-azaisoindigo derivative [namely N(1)-(n-butyl)-7-azaisoindigo, 7-AI-b], and investigated its molecular antitumor mechanism by exploring the means of cell death and the effects on mitochondrial function. 7-AI-b inhibited cancer cell proliferation in a dose- and time-dependent way. The morphological and nuclei changes in H(2) B-GFP-labeled HeLa cells were observed using a live cell system. The results suggested that cell death induced by 7-AI-b is closely related to apoptosis. 7-AI-b induced release of cytochrome C from mitochondria to cytosol and activation of caspase-3, showing that the apoptosis is mediated by the mitochondrial pathway. Furthermore, our data indicated that 7-AI-b triggers apoptosis through reactive oxygen species (ROS): cellular ROS levels were increased after 3 h exposure of 7-AI-b, which was reversed by the ROS scavenger N-acetyl-L-cysteine. As a consequence, 7-AI-b-mediated cell death, mitochondrial transmembrane potential collapse and ATP level were partly blocked by N-acetyl-L-cysteine. Further study showed that 7-AI-b could induce mitochondrial dysfunction: collapse of the mitochondrial transmembrane potential and reduction of intracellular ATP level. In summary, the novel synthesized 7-AI-b was demonstrated to be effective in killing cancer cells via an ROS-promoted and mitochondria- and caspase-dependent apoptotic pathway.
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Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Indoles/farmacología , Mitocondrias/efectos de los fármacos , Neoplasias/tratamiento farmacológico , Estrés Oxidativo/efectos de los fármacos , Acetilcisteína/farmacología , Adenosina Trifosfato/metabolismo , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Depuradores de Radicales Libres/farmacología , Humanos , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/metabolismo , Neoplasias/metabolismo , Neoplasias/patología , Concentración Osmolar , Especies Reactivas de Oxígeno/metabolismo , Factores de TiempoRESUMEN
The conversion of Kraft lignin in plant biomass into renewable chemicals, aiming at harvesting aromatic compounds, is a challenge process in biorefinery. Comparing to the traditional chemical methods, enzymatic catalysis provides a gentle way for the degradation of lignin. Alternative to natural enzymes, artificial enzymes have been received much attention for potential applications. We herein achieved the biodegradation of Kraft lignin using an artificial peroxidase rationally designed in myoglobin (Mb), F43Y/T67R Mb, with a covalently linked heme cofactor. The artificial enzyme of F43Y/T67R Mb has improved catalytic efficiencies at mild acidic pH for phenolic and aromatic amine substrates, including Kraft lignin and the model lignin dimer guaiacylglycerol-ß-guaiacyl ether (GGE). We proposed a possible catalytic mechanism for the biotransformation of lignin catalyzed by the enzyme, based on the results of kinetic UV-Vis studies and UPLC-ESI-MS analysis, as well as molecular modeling studies. With the advantages of F43Y/T67R Mb, such as the high-yield by overexpression in E. coli cells and the enhanced protein stability, this study suggests that the artificial enzyme has potential applications in the biodegradation of lignin to provide sustainable bioresource.
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BACKGROUND: Activating transcription factor 6 (ATF6) and receptor-interacting protein 3 (RIP3) are important signaling proteins in endoplasmic reticulum (ER) stress and necroptosis, respectively. However, their regulatory relationship and clinical significance are unknown. We investigate the impact of ATF6 on RIP3 expression, and its role in hepatocyte necroptosis in an acute liver injury model. METHODS: In vivo and in vitro experiments were carried out. LO2 cells were treated with thapsigargin (TG). In vivo, male BALB/c mice were treated with carbon tetrachloride (CCl4, 1 mL/kg) or tunicamycin (TM, 2 mg/kg). Then, the impact of ATF6 or RIP3 silencing on liver injury, hepatocyte necroptosis, and ER stress-related protein expression was examined. RESULTS: TG induced ER stress and necroptosis and ATF6 and RIP3 expression in LO2 cells. The knockdown of ATF6 significantly decreased RIP3 expression (p < 0.05) and increased ER stress and necroptosis. The downregulation of RIP3 significantly reduced necroptosis and ER stress (p < 0.05). Similar results were observed in CCl4 or the TM-induced mouse model. The knockdown of ATF6 significantly decreased CCl4-induced RIP3 expression and increased liver injury, necroptosis, and ER stress in mice livers (p < 0.05). In contrast, the downregulation of RIP3 significantly reduced liver injury, hepatocyte necroptosis, and ER stress. CONCLUSIONS: Hepatocyte ATF6 has multiple roles in acute liver injury. It reduces hepatocyte necroptosis via negative feedback regulation of ER stress. In addition, ATF6 can upregulate the expression of RIP3, which is not helpful to the recovery process. However, downregulating RIP3 reduces hepatocyte necroptosis by promoting the alleviation of ER stress. The findings suggest that RIP3 could be a plausible target for the treatment of liver injury.
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Factor de Transcripción Activador 6/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Factor de Transcripción Activador 6/genética , Animales , Apoptosis , Enfermedad Hepática Inducida por Sustancias y Drogas/genética , China , Modelos Animales de Enfermedad , Estrés del Retículo Endoplásmico/genética , Hepatocitos/metabolismo , Hígado/metabolismo , Hígado/patología , Masculino , Ratones , Ratones Endogámicos BALB C , Modelos Animales , Necroptosis/genética , Necroptosis/fisiología , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Transducción de Señal/genéticaRESUMEN
BACKGROUND: The tumor volume of high-grade glioma (HGG) after surgery is usually determined by contrast-enhanced MRI (CE-MRI), but the clinical target volume remains controversial. Functional magnetic resonance imaging (multimodality MRI) techniques such as magnetic resonance perfusion-weighted imaging (PWI) and diffusion-tensor imaging (DTI) can make up for CE-MRI. This study explored the survival outcomes and failure patterns of patients with HGG by comparing the combination of multimodality MRI and CE-MRI imaging with CE-MRI alone. METHODS: 102 patients with postoperative HGG between 2012 and 2016 were included. 50 were delineated based on multimodality MRI (PWI, DTI) and CE-MRI (enhanced T1), and the other 52 were delineated based on CE-MRI as control. RESULTS: The median survival benefit was 6 months. The 2-year overall survival, progression-free survival, and local-regional control rates were 48% vs. 25%, 42% vs. 13.46%, and 40% vs. 13.46% for the multimodality MRI and CE-MRI cohorts, respectively. The two cohorts had similar rates of disease progression and recurrence but different proportions of failure patterns. The univariate analysis shows that characteristics of patients such as combined with epilepsy, the dose of radiotherapy, the selection of MRI were significant influence factors for 2-year overall survival. However, in multivariate analyses, only the selection of MRI was an independent significant predictor of overall survival. CONCLUSIONS: This study was the first to explore the clinical value of multimodality MRI in the delineation of radiotherapy target volume for HGG. The conclusions of the study have positive reference significance to the combination of multimodality MRI and CE-MRI in guiding the delineation of the radiotherapy target area for HGG patients.
Asunto(s)
Imagen de Difusión por Resonancia Magnética , Glioma/diagnóstico por imagen , Angiografía por Resonancia Magnética , Recurrencia Local de Neoplasia/diagnóstico por imagen , Adolescente , Adulto , Anciano , Niño , Femenino , Glioma/diagnóstico , Glioma/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Imagen Multimodal/métodos , Clasificación del Tumor , Recurrencia Local de Neoplasia/diagnóstico , Recurrencia Local de Neoplasia/patología , Adulto JovenRESUMEN
High fructose intake promotes hepatic lipid accumulation. Pterostilbene, a natural analogue of resveratrol found in diet berries, exhibits a hepatoprotective property. Here, we studied the protection by pterostilbene against fructose-induced hepatic lipid accumulation and explored its possible mechanism. We observed a high expression of microRNA-34a (miR-34a, P < 0.05) and a low expression of its target, sirtuin1 (Sirt1, mRNA: P < 0.01; protein: P < 0.001), with the overactivation of downstream sterol regulatory element-binding protein-1 (SREBP-1) lipogenic pathway (nuclear SREBP-1 protein: P < 0.05; FAS and SCD1 mRNA: P < 0.01), in rat livers, as well as BRL-3A and HepG2 cells, stimulated by fructose. More interestingly, pterostilbene recovered the fructose-disturbed miR-34a expression (0.3-0.5-fold vs fructose control, P < 0.05), Sirt1 protein level (1.2- to 1.5-fold vs fructose control, P < 0.05), and SREBP-1 lipogenic pathway, resulting in significant amelioration of hepatocyte lipid accumulation in animal [hepatic triglyceride and total cholesterol (TG&TC) mg/g·wet tissue: 4.90 ± 0.19, 5.23 ± 0.16, 5.20 ± 0.29 vs fructose control 9.73 ± 1.06, P < 0.001; 3.18 ± 0.30, 3.31 ± 0.39, 3.37 ± 0.47 vs 5.67 ± 0.28, P < 0.001] and cell models (BRL-3A TG&TC mmol/g·protein: 0.123 ± 0.011 vs 0.177 ± 0.004, P < 0.001; 0.169 ± 0.011 vs 0.202 ± 0.008, P < 0.05; HepG2: 0.257 ± 0.005 vs 0.303 ± 0.016, P < 0.05; 0.143 ± 0.004 vs 0.201 ± 0.008, P < 0.001). These results provide the experimental evidence supporting the anti-lipogenic effect of pterostilbene against fructose-induced hepatic lipid accumulation via modulating the miR-34a/Sirt1/SREBP-1 pathway.
Asunto(s)
Fructosa/metabolismo , Hígado/efectos de los fármacos , MicroARNs/metabolismo , Sirtuina 1/metabolismo , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/metabolismo , Estilbenos/administración & dosificación , Animales , Colesterol/metabolismo , Fructosa/efectos adversos , Hígado/metabolismo , Masculino , MicroARNs/genética , Ratas , Ratas Sprague-Dawley , Sirtuina 1/genética , Proteína 1 de Unión a los Elementos Reguladores de Esteroles/genética , Triglicéridos/metabolismoRESUMEN
Copper(II) complexes of ethyl 2-[bis(2-pyridylmethyl)amino]propionate ligand (ETDPA) have been synthesized and characterized by elemental analyses, IR spectra, UV spectra and ES-MS. These complexes are stable in air with the formula of [(ETDPA)CuCl(2)] and [(ETDPA)Cu(phen)](ClO(4))(2). The DNA-binding properties of the Cu(II) complexes have been investigated by ultraviolet spectroscopy and fluorescence spectroscopy, which showed that the binding mode of the two complexes with DNA was different. The binding mode of [(ETDPA)CuCl(2)] is not the classical intercalation binding, and the binding mode of [(ETDPA)Cu(phen)](ClO(4))(2) with DNA is intercalation. The cytotoxic assay shows that the [(ETDPA)Cu(phen)](ClO(4))(2) is more active on the proliferation of cancer cells than the [(ETDPA)CuCl(2)].
Asunto(s)
Cobre/química , Cobre/toxicidad , ADN/metabolismo , Propionatos/química , Animales , Tampones (Química) , Bovinos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Formazáns/metabolismo , Células HeLa , Humanos , Concentración de Iones de Hidrógeno , Ligandos , Espectrometría de Fluorescencia , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Infrarroja , Espectrofotometría Ultravioleta , Electricidad Estática , Temperatura , Sales de Tetrazolio/metabolismo , Termodinámica , VibraciónRESUMEN
Cinnamoyl-containing nonribosomal peptides (CCNPs) are a small group of secondary metabolites with potent biological activities produced by actinobacteria. Two remarkable features in the biosynthesis of CCNPs include the nonribosomal peptide synthases (NRPSs) for assembly of the depsipeptide backbone and the type II polyketide synthases (PKSs) for N-terminal cinnamoyl moiety construction. Here, we present a genome mining approach targeting both NRPS and type II PKS for discovery of new CCNPs, which led to the identification of 51 putative CCNP gene clusters from public bacterial genome databases. After strain prioritization, a novel class of CCNP-type glycopeptides named kitacinnamycins, one of which showing potent activation ability towards the stimulator of interferon genes (STING) protein, was identified. Bioinformatic, genetic and biochemical analysis revealed the use of the NRPS assembly line to form the macrocyclic peptide backbone, followed by a P450 monooxygenase to generate terminal oxidized groups. A glycosyltransferase with relatively broad substrate specificity transfers sugars to the newly generated OH/COOH group. The protein crystallographic study further provided structural insights into this glycosylation. Our results not only demonstrated the feasibility of genome mining and strain prioritization for the discovery of new bioactive natural products but also disclosed the biosynthetic pathway for kitacinnamycins.