RESUMEN
Hypoxia-inducible factor-1α (HIF-1α) is considered the main transcriptional regulator of the hypoxia-specific cellular and developmental response. This study was performed to investigate the effect of Shenqin biochemical extract (SQBE) on HIF-1α expression in ultraviolet B (UVB)-irradiated HaCaT cells and the possible action mechanisms of SQBE against UVB-induced skin cancer. HaCaT cells in logarithmic growth phase were seeded in Dulbecco's modified Eagle's medium with 10% fetal bovine serum, and conventionally cultured at 37°C with 5% CO2. Cells were divided into control group (administered the same amounts of dimethyl sulfoxide), SQBE1 group (12.5 µg/mL SQBE), SQBE2 group (25.0 µg/mL SQBE), and SQBE3 group (50.0 µg/mL SQBE). Four hours post administration, the control and treatment groups were irradiated with UVB (0, 20, 40, and 60 mJ/cm2). After 24 h, cell survival rate was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Expression levels of HIF-1α mRNA and protein were detected by polymerase chain reaction and western blotting, respectively. SQBE-treated, UVB-irradiated cells had improved survival rates. This increase was most significant in SQBE3 group (P < 0.01), which also had effectively reduced expression of intracellular HIF-1α mRNA and protein. Hence, SQBE had a protective effect on UVB-irradiated HaCaT cells and inhibited the UVB irradiation-induced expression of HIF-1α. This indicates that SQBE could prevent the occurrence of UVB radiation-induced skin cancer.
Asunto(s)
Medicamentos Herbarios Chinos/farmacología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Línea Celular Tumoral , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Queratinocitos/efectos de los fármacos , Queratinocitos/metabolismo , Queratinocitos/efectos de la radiación , Panax/química , Scutellaria/química , Rayos UltravioletaRESUMEN
The epithelium is a highly dynamic system, which plays a crucial role in the homeostasis of the intestinal tract. However, studies on the physiological and pathophysiological functions of intestinal epithelial cells (IECs) have been hampered due to lack of normal epithelial cell models. In the present study, we established a reproducible method for primary culture of mouse IECs, which were isolated from the viable small intestinal crypts of murine fetuses (on embryonic day 19), using type I collagenase and hyaluronidase in a short span of time (≤20 min). With this method, continuously growing mouse IECs, which can be subcultured over a number of passages, were obtained. The obtained cell lines formed a tight cobblestone-like arrangement, displayed long and slender microvilli, expressed characteristic markers (cytokeratin 18 and Notch-1), and generated increasing transepithelial electrical resistance and low paracellular permeability during in vitro culture. The cells also had enzymatic activities of alkaline phosphatase and sucrase-isomaltase, and secreted various cytokines (IL-1ß, IL-6, IL-8, and monocyte chemoattractant protein-1), responding to the stimulation of Escherichia coli. These results show that the primary-cultured mouse IECs obtained by the method established here had the morphological and immunological characteristics of IECs. This culture system can be a beneficial in vitro model for studies on mucosal immunology and toxicology.
Asunto(s)
Técnicas de Cultivo de Célula/métodos , Células Epiteliales/citología , Hialuronoglucosaminidasa , Intestino Delgado/citología , Metaloproteinasa 13 de la Matriz , Animales , Proliferación Celular , Células Cultivadas , Colagenasas , Citocinas/metabolismo , Células Epiteliales/metabolismo , Femenino , Técnica del Anticuerpo Fluorescente , Hematoxilina , Masculino , Ratones Endogámicos BALB C , Microscopía Electrónica de Rastreo , Microscopía Electrónica de Transmisión , Reproducibilidad de los Resultados , Factores de TiempoRESUMEN
Calcium plays a critical role in regulating abiotic stress responses in plants. Calcineurin B-like (CBL) proteins are calcium sensors in calcium signaling pathways. However, the molecular mechanisms underlying calcium signaling remain to be elucidated. In this study, the CBL1 gene, which codes for the CBL protein, was isolated from the birch-leaf pear. One 2,969-bp sequence was cloned using PCR, and using the cloned 2,027-bp sequence was isolated from pear genomic DNA via genome walking. Sequencing analysis revealed that the 4,996-bp sequence was a PbCBL1 gene consisting of eight exons and seven introns, and the 2,027-bp sequence was identified as the promoter of the PbCBL1 gene, which contains the basic promoter elements TATA and CAAT boxes. In addition, some other cis-acting elements including heat, cold, drought, and hormone responsive elements were also present. To further investigate the activity of this promoter, the sequence was used to drive a GUS fusion gene into leaf discs of tobacco (Nicotiana benthamiana) with Agrobacterium-mediated transformation method. GUS gene expression could be regulated by the PbCBL1 promoter following induction by GA, ABA, SA, and MeJA. Furthermore, the results of real-time RT-qPCR indicate that the PbCBL1 gene can respond to changes in the intracellular calcium concentration, and that it can be induced by cold, heat, drought, and stress by several hormones including GA, ABA, SA, and MeJA. PbCBL1 gene may be involved in several signal transduction pathways, and play an important role in the condition of adversity stress in pear.
Asunto(s)
Proteínas de Unión al Calcio/genética , Clonación Molecular , Proteínas de Plantas/genética , Regiones Promotoras Genéticas , Pyrus/genética , Región de Flanqueo 5' , Secuencia de Aminoácidos , Secuencia de Bases , Expresión Génica , Orden Génico , Genes Reporteros , Vectores Genéticos , Datos de Secuencia Molecular , Motivos de Nucleótidos , Proteínas Recombinantes de Fusión , Secuencias Reguladoras de Ácidos Nucleicos , Reproducibilidad de los Resultados , Alineación de Secuencia , Análisis de Secuencia de ADN , Transformación GenéticaRESUMEN
Anthocyanidin synthase (ANS), a 2-oxoglutarate (2OG) and Fe(II)-dependent oxygenase, catalyzes the penultimate step in anthocyanin biosynthesis, from leucoanthocyanidins to anthocyanidins, the first colored compound in the anthocyanin pathway. In this study, a full-length, 1427-bp long cDNA named RnANS1, which is homologous to the anthocyanidin synthase gene, was cloned from blackcurrant using a homologous cloning strategy. RnANS1 is highly homologous to other plant ANS genes at both the nucleotide and amino acid sequence levels. The deduced protein contains domains conserved in the 2OG and Fe(II)-dependent oxygenase, and is phylogenetically closely related to Paeonia suffruticosa and Paeonia lactiflora. The expression of RnANS1 was upregulated during fruit maturation, and correlated with the accumulation of anthocyanins and soluble carbohydrates in the fruit. Further characterization of the structure and expression patterns of RnANS1 will clarify our understanding of anthocyanin biosynthesis in blackcurrant, and support the development of molecular approaches to manipulate anthocyanin production in this plant.
Asunto(s)
Frutas/genética , Perfilación de la Expresión Génica , Oxigenasas/genética , Proteínas de Plantas/genética , Ribes/genética , Secuencia de Aminoácidos , Antocianinas/metabolismo , Carbohidratos/análisis , Clonación Molecular , ADN Complementario/química , ADN Complementario/genética , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Oxigenasas/clasificación , Oxigenasas/metabolismo , Filogenia , Proteínas de Plantas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ribes/crecimiento & desarrollo , Ribes/metabolismo , Análisis de Secuencia de ADN , Homología de Secuencia de AminoácidoRESUMEN
Wood formation occurs via cell division, primary cell wall and secondary wall formation, and programmed cell death in the vascular cambium. Transcriptional profiling of secondary xylem differentiation is essential for understanding the molecular mechanisms underlying wood formation. Differential gene expression in secondary xylem differentiation of Populus has been previously investigated using cDNA microarray analysis. However, little is known about the molecular mechanisms from a genome-wide perspective. In this study, the Affymetrix poplar genome chips containing 61,413 probes were used to investigate the changes in the transcriptome during secondary xylem differentiation in Chinese white poplar (Populus tomentosa). Two xylem tissues (newly formed and lignified) were sampled for genome-wide transcriptional profiling. In total, 6843 genes (~11%) were identified with differential expression in the two xylem tissues. Many genes involved in cell division, primary wall modification, and cellulose synthesis were preferentially expressed in the newly formed xylem. In contrast, many genes, including 4-coumarate:cinnamate-4-hydroxylase (C4H), 4-coumarate:CoA ligase (4CL), cinnamyl alcohol dehydrogenase (CAD), and caffeoyl CoA 3-O-methyltransferase (CCoAOMT), associated with lignin biosynthesis were more transcribed in the lignified xylem. The two xylem tissues also showed differential expression of genes related to various hormones; thus, the secondary xylem differentiation could be regulated by hormone signaling. Furthermore, many transcription factor genes were preferentially expressed in the lignified xylem, suggesting that wood lignification involves extensive transcription regulation. The genome-wide transcriptional profiling of secondary xylem differentiation could provide additional insights into the molecular basis of wood formation in poplar species.
Asunto(s)
Diferenciación Celular/genética , Perfilación de la Expresión Génica , Genoma de Planta , Populus/genética , Transcripción Genética , Xilema/citología , Xilema/genética , Ciclo Celular/genética , Pared Celular/genética , Regulación de la Expresión Génica de las Plantas , Ontología de Genes , Lignina/metabolismo , Anotación de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcriptoma/genéticaRESUMEN
A 1794-bp cDNA fragment was amplified from mRNA isolated from pear (Pyrus pyrifolia NaKai. Cuiguan) leaves by using primers based on the sequences generated during the analysis of the pear transcriptome. The 597-amino acid sequence encoded by the cDNA was compared with the sequences in GenBank, and it was found to be similar to that of members of the sucrose-proton co-transporter family. The hydrophobic protein, which was predicted to have 11 transmembrane domains, was designated as PpSUT2. Real-time fluorescent quantitative polymerase chain reaction analysis indicated the accumulation of PpSUT2 mRNA throughout the plant, with the highest levels in the buds. Analysis of the expression of PpSUT2 during fruit development showed that the abundance of its transcripts increased at the end of April and then decreased to the lowest level at the end of July. Subcellular localization studies with the pCXDG vector as a probe demonstrated that PpSUT2 localized to cell membranes. An expression vector was constructed by inserting the PpSUT2 cDNA into pET32(a), and the vector was expressed in Escherichia coli (strain BL21) after induction with 1 mM isopropyl b-d-1-thiogalactopyranoside at 25°C. Analysis using sodium dodecyl sulfate-polyacrylamide gel electrophoresis identified the induction of a 71-kDa protein. Further analysis indicated that PpSUT2 might be not directly involved in sucrose transport, instead, functioning as a sucrose sensor on the cytoplasmic membrane.