Identification of banana ADA1 gene family members and their expression profiles under biotic and abiotic stresses / 生物工程学报

The Spt-Ada-Gcn5-acetyltransferase (SAGA) is an ancillary transcription initiation complex which is highly conserved. The ADA1 (alteration/deficiency in activation 1, also called histone H2A functional interactor 1, HFI1) is a subunit in the core module of the SAGA protein complex. ADA1 plays an important role in plant growth and development as well as stress resistance. In this paper, we performed genome-wide identification of banana ADA1 gene family members based on banana genomic data, and analyzed the basic physicochemical properties, evolutionary relationships, selection pressure, promoter cis-acting elements, and its expression profiles under biotic and abiotic stresses. The results showed that there were 10, 6, and 7 family members in Musa acuminata, Musa balbisiana and Musa itinerans. The members were all unstable and hydrophilic proteins, and only contained the conservative SAGA-Tad1 domain. Both MaADA1 and MbADA1 have interactive relationship with Sgf11 (SAGA-associated factor 11) of core module in SAGA. Phylogenetic analysis revealed that banana ADA1 gene family members could be divided into 3 classes. The evolution of ADA1 gene family members was mostly influenced by purifying selection. There were large differences among the gene structure of banana ADA1 gene family members. ADA1 gene family members contained plenty of hormonal elements. MaADA1-1 may play a prominent role in the resistance of banana to cold stress, while MaADA1 may respond to the Panama disease of banana. In conclusion, this study suggested ADA1 gene family members are highly conserved in banana, and may respond to biotic and abiotic stress.

Phosphoproteomic analysis of human umbilical venous endothelial cells with DENV-2 infection / 南方医科大学学报

OBJECTIVE@#To analyze the differentially phosphorylated proteins in DENV-2-infected human umbilical venous endothelial cells (HUVECs) and explore the possible pathogenic mechanism of DENV-2 infection.@*METHODS@#The total proteins were extracted from DENV-2-infected HUVECs and blank control HUVEC using SDT lysis method. The phosphorylated proteins were qualitatively and quantitatively analyzed using tandem mass spectrometry (TMT). The identified differentially phosphorylated proteins were analyzed by bioinformatics analyses such as subcellular localization analysis, GO enrichment analysis, KEGG pathway analysis and protein-protein interaction (PPI) analysis. Western blotting was used to detect the expressions of phosphorylated Jun, map2k2 and AKT1 proteins in DENV-2-infected HUVECs.@*RESULTS@#A total of 2918 modified peptides on 1385 different proteins were detected, and among them 1346 were significantly upregulated (FC > 1.2, P < 0.05) and 1572 were significantly downregulated (FC < 0.83, P < 0.05). A total of 49 phosphorylated conserved motifs were obtained by amino acid conservative motif analysis. The most abundant differentially phosphorylated peptides in protein domain analysis included RNA recognition motif, protein kinase domain and PH domain. Subcellular localization analysis showed that the differentially modified peptides were mainly localized in the nucleus and cytoplasm. GO enrichment and KEGG pathway analysis showed that the differential peptides were mainly enriched in the regulation of stimulation response, biosynthesis of small molecules containing nuclear bases, and migration of phagosomes and leukocytes across the endothelium. PPI and KEGG joint analysis showed that the up-regulated and down-regulated differentially phosphorylated proteins were enriched in 15 pathways. In DENV-2-infected HUVECs, Western blotting detected differential expressions of phosphorylated proteins related with the autophagy pathway, namely JUN, MAP2K2 and AKT1, and among them p-JUN was significantly down-regulated and p-AKT1 and p-MAP2K2 were significantly upregulated (P < 0.01).@*CONCLUSION@#DENV-2 infected HUVECs show numerous differentially expressed proteins. The downregulation of p-JUN and upregulation of p-MAP2K2 and p-AKT1 suggest their potential roles in regulating autophagy, which is probably involved in the mechanism of DENV-2 infection.

A molecular brake that modulates spliceosome pausing at detained introns contributes to neurodegeneration

Emerging evidence suggests that intron-detaining transcripts (IDTs) are a nucleus-detained and polyadenylated mRNA pool for cell to quickly and effectively respond to environmental stimuli and stress. However, the underlying mechanisms of detained intron (DI) splicing are still largely unknown. Here, we suggest that post-transcriptional DI splicing is paused at the Bact state, an active spliceosome but not catalytically primed, which depends on Smad Nuclear Interacting Protein 1 (SNIP1) and RNPS1 (a serine-rich RNA binding protein) interaction. RNPS1 and Bact components preferentially dock at DIs and the RNPS1 docking is sufficient to trigger spliceosome pausing. Haploinsufficiency of Snip1 attenuates neurodegeneration and globally rescues IDT accumulation caused by a previously reported mutant U2 snRNA, a basal spliceosomal component. Snip1 conditional knockout in the cerebellum decreases DI splicing efficiency and causes neurodegeneration. Therefore, we suggest that SNIP1 and RNPS1 form a molecular brake to promote spliceosome pausing, and that its misregulation contributes to neurodegeneration.

Advances in cell nuclear mechanobiology and its regulation mechanisms / 生物医学工程学杂志

As an important intracellular genetic and regulatory center, the nucleus is not only a terminal effector of intracellular biochemical signals, but also has a significant impact on cell function and phenotype through direct or indirect regulation of nuclear mechanistic cues after the cell senses and responds to mechanical stimuli. The nucleus relies on chromatin-nuclear membrane-cytoskeleton infrastructure to couple signal transduction, and responds to these mechanical stimuli in the intracellular and extracellular physical microenvironments. Changes in the morphological structure of the nucleus are the most intuitive manifestation of this mechanical response cascades and are the basis for the direct response of the nucleus to mechanical stimuli. Based on such relationships of the nucleus with cell behavior and phenotype, abnormal nuclear morphological changes are widely used in clinical practice as disease diagnostic tools. This review article highlights the latest advances in how nuclear morphology responds and adapts to mechanical stimuli. Additionally, this article will shed light on the factors that mechanically regulate nuclear morphology as well as the tumor physio-pathological processes involved in nuclear morphology and the underlying mechanobiological mechanisms. It provides new insights into the mechanisms that nuclear mechanics regulates disease development and its use as a potential target for diagnosis and treatment.

The morphological challenge in determining nuclear size and shape in anatomopathological neoplasia analysis / El desafío morfológico en la determinación del tamaño y forma nuclear en el análisis anatomopatológico de neoplasias

SUMMARY: From 1984 stereology was added to unbiased methods and procedures, i.e., counts became more reliable studying morphological images in a random and uniform isotropic way. Therefore, the orientation and sectioning methods adapted to stereological quantification are essential. A critical quantitative subject in practical pathology concerns diagnosing and classifying neoplasias. Pathologists evaluated different types of tumors by determining the nuclear roundness factor (NRF). NRF is calculated by the ratio between the nuclear radius obtained from the area and the perimeter. However, NRF is biased data because it depends on the sectioning orientation, nuclei shape, and section thickness. The stereology proposed an unbiased alternative to assess the nucleus from tumor cells, counteracting NRF quantitatively. Therefore, the volume-weighted mean nuclear volume has been used to prognostic tumors in several organs. In urology, this was used, for example, to study primary carcinoma of the bladder, renal and prostatic carcinomas.

RESUMEN: A partir de 1984 se agregó la estereología a los métodos y procedimientos sin distorción, es decir, los conteos se volvieron más confiables al estudiar imágenes morfológicas de forma aleatoria e isotrópica uniforme. Por tanto, los métodos de orientación y seccionamiento adaptados a la cuantificación estereológica son fundamentales. Un tema cuantitativo crítico en la patología práctica se refiere al diagnóstico y clasificación de las neoplasias. Los patólogos evaluaron diferentes tipos de tumores determinando el factor de redondez nuclear (NRF). NRF se calcula por la relación entre el radio nuclear obtenido del área y el perímetro. Sin embargo, NRF son datos distorsionados debido a que dependen de la orientación de la sección, la forma de los núcleos y el grosor de la sección. La estereología propuso una alternativa imparcial para evaluar el núcleo de las células tumorales, contrarrestando cuantitativamente el NRF. Por lo tanto, el volumen nuclear medio ponderado se ha utilizado para pronosticar tumores en varios órganos. En urología, esto se utilizó, por ejemplo, para estudiar el carcinoma primario de vejiga, carcinomas renales y prostáticos.

The nucleocapsid protein of rice stripe virus in cell nuclei of vector insect regulates viral replication

Rice stripe virus (RSV) transmitted by the small brown planthopper causes severe rice yield losses in Asian countries. Although viral nuclear entry promotes viral replication in host cells, whether this phenomenon occurs in vector cells remains unknown. Therefore, in this study, we systematically evaluated the presence and roles of RSV in the nuclei of vector insect cells. We observed that the nucleocapsid protein (NP) and viral genomic RNAs were partially transported into vector cell nuclei by utilizing the importin α nuclear transport system. When blocking NP nuclear localization, cytoplasmic RSV accumulation significantly increased. In the vector cell nuclei, NP bound the transcription factor YY1 and affected its positive regulation to FAIM. Subsequently, decreased FAIM expression triggered an antiviral caspase-dependent apoptotic reaction. Our results reveal that viral nuclear entry induces completely different immune effects in vector and host cells, providing new insights into the balance between viral load and the immunity pressure in vector insects.

Nuclear cGAS: sequestration and beyond

The cyclic GMP-AMP (cGAMP) synthase (cGAS) has been identified as a cytosolic double stranded DNA sensor that plays a pivotal role in the type I interferon and inflammation responses via the STING-dependent signaling pathway. In the past several years, a growing body of evidence has revealed that cGAS is also localized in the nucleus where it is associated with distinct nuclear substructures such as nucleosomes, DNA replication forks, the double-stranded breaks, and centromeres, suggesting that cGAS may have other functions in addition to its role in DNA sensing. However, while the innate immune function of cGAS is well established, the non-canonical nuclear function of cGAS remains poorly understood. Here, we review our current understanding of the complex nature of nuclear cGAS and point to open questions on the novel roles and the mechanisms of action of this protein as a key regulator of cell nuclear function, beyond its well-established role in dsDNA sensing and innate immune response.

An investigation on the chloroplast and nuclear genomes of taxa belong to the subgenus Dracunculus (Bess.) Rydb. of Artemisia L. (Asteraceae) in Turkey / Uma investigação sobre o cloroplasto e os genomas nucleares de táxons pertencentes ao subgênero Dracunculus (Bess.) Rydb. de Artemisia L. (Asteraceae) na Turquia

Artemisia is one of the biggest genera in the family Asteraceae, with around 500-600 taxa at specific and subspecific levels and organised in 5 subgenera. Due to the high number of taxa, a lot taxonomists are trying to solve the problem of its classification and phylogeny but its natural classification still hasn't been achieved. In this research, 60 individuals belonging to 4 taxa of the subgenus Dracunculus of Artemisia L. in Turkey were examined. For all the examined individuals from both the same and different populations belonging to the taxa of the subgenus Dracunculus, the sequences of the regions both psbA-trnH of chloroplast DNA and ITS of nuclear DNA were determined. Also, the gene regions obtained were recorded in the NCBI GenBank database and an accession number was taken. It was found that there was no gene flow and hybridization between the four studied taxa of the subgenus Dracunculus, and these 4 taxa also completed their speciation. According to the results of this molecular study, A. campestris var. campestris, A. campestris var. marschalliana and A. campestris var. araratica were proposed to be raised from the variety level to the species level. This research is important as it is the first molecular based study relating with the subgenus Dracunculus growing in Turkey.

Artemisia é um dos maiores gêneros da família Asteraceae, com cerca de 500 a 600 táxons em níveis específicos e subespecíficos e organizados em cinco subgêneros. Em razão do grande número de táxons, muitos taxonomistas estão tentando resolver o problema de sua classificação e filogenia, mas sua classificação natural ainda não foi alcançada. Nesta pesquisa, 60 indivíduos pertencentes a quatro táxons do subgênero Dracunculus de Artemisia L. na Turquia foram examinados. Para todos os indivíduos examinados de populações iguais e diferentes pertencentes aos táxons do subgênero Dracunculus, foram determinadas as sequências das regiões psbA-trnH do DNA do cloroplasto e ITS do DNA nuclear. Além disso, as regiões gênicas obtidas foram registradas no banco de dados do NCBI GenBank e um número de acesso foi obtido. Foi constatado que não houve fluxo gênico nem hibridização entre os quatro táxons estudados do subgênero Dracunculus, os quais também completaram sua especiação. De acordo com os resultados deste estudo molecular, A. campestris var. campestris, A. campestris var. marschalliana e A. campestris var. araratica foram propostos para ser elevados do nível de variedade para o nível de espécie. Esta pesquisa é importante porque é o primeiro estudo de base molecular relacionado com o subgênero Dracunculus em crescimento na Turquia.

Nuclear elongation correlates with neurite induced cellular elongation during differentiation of SH-SY5Y neural cells / El alargamiento del núcleo se correlaciona con el alargamiento celular inducido por neuritas durante la diferenciación de las células neuronales Sh-Sy5Y

SUMMARY: Cellular differentiation is a highly regulated process that has vast implications for the mechanics of the cell. The interplay between differentiation induced cytoskeletal mechanical changes and strain on the nucleus is a potential cause of gene level changes. This study explores mechanical changes in SH-SY5Y neural cells during differentiation mediated by Retinoic Acid (RA) across Days 0 through 9. Findings suggest that cellular elongation increases 1.92-fold over a 10-day differentiation period, from 48.97 ±16.85µm to 93.96 ± 31.20 µm over 3 repeated trials and across multiple cells analyzed on ImageJ. Nuclear elongation increases less substantially from 17.51 ± 2.71 µm to 23.26 ± 3.10 µm over 3 repeated trials and across multiple cells. Results are statistically significant at a significance level of α = 0.05. This study is one of the first studies to show that during the process of RA mediated neural differentiation in SH-SY5Y neural cells, nuclear elongation is initially not significantly correlated with cellular elongation, but it becomes correlated during the differentiation process with an overall correlation coefficient of 0.4498 at a significance level of α = 0.05. Given the time course of the mechanical changes and the known coupling between the cytoskeleton and nuclear lamina, this study suggests a causative and correlative relationship between neurite-driven cellular elongation and nuclear elongation during neural differentiation.

RESUMEN: La diferenciación celular es un proceso altamente regulado que tiene vastas implicaciones para la mecánica de la célula. La interacción entre los cambios mecánicos citoesqueléticos inducidos por la diferenciación y la tensión en el núcleo es una causa potencial de cambios a nivel genético. Este estudio explora los cambios mecánicos en las células neurales SH-SY5Y durante la diferenciación mediada por el ácido retinoico (RA) durante los días 0 a 9. Los resultados sugieren que el alargamiento celular aumenta 1,92 veces durante un período de diferenciación de 10 días, de 48,97 ± 16,85 µm a 93,96 ± 31,20 µm en 3 ensayos repetidos y en múltiples células analizadas en Image J. El alargamiento nuclear aumenta menos sustancialmente de 17,51 ± 2,71 µm a 23,26 ± 3,10 µm durante 3 ensayos repetidos y en múltiples células. Los resultados son estadísticamente significativos a un nivel de significancia de α = 0,05. Esta investigación es uno de los primeros estudios en demostrar que durante el proceso de diferenciación neural mediada por RA en las células neurales SH-SY5Y, el alargamiento nuclear inicialmente no se correlaciona significativamente con el alargamiento celular, pero se correlaciona durante el proceso de diferenciación con un coeficiente de correlación global de 0,4498 a un nivel de significancia de α = 0,05. Dado el curso temporal de los cambios mecánicos y el acoplamiento conocido entre el citoesqueleto y la lámina nuclear, este estudio sugiere una relación causal y correlativa entre el alargamiento celular impulsado por neuritas y el alargamiento nuclear durante la diferenciación neural.

Nuclear Dbf2-related Kinase 1 functions as tumor suppressor in glioblastoma by phosphorylation of Yes-associated protein / 中华医学杂志(英文版)

BACKGROUND@#The Nuclear Dbf2-related (NDR1) kinase is a member of the NDR/LATS family, which was a supplementary of Hippo pathway. However, whether NDR1 could inhibit glioblastoma (GBM) growth by phosphorylating Yes-associated protein (YAP) remains unknown. Meanwhile, the role of NDR1 in GBM was not clear. This study aimed to investigate the role of NDR1-YAP pathway in GBM.@*METHODS@#Bioinformation analysis and immunohistochemistry (IHC) were performed to identify the expression of NDR1 in GBM. The effect of NDR1 on cell proliferation and cell cycle was analyzed utilizing CCK-8, clone formation, immunofluorescence and flow cytometry, respectively. In addition, the xenograft tumor model was established as well. Protein interaction was examined by Co-immunoprecipitation and immunofluorescence to observe co-localization.@*RESULTS@#Bioinformation analysis and IHC of our patients' tumor tissues showed that expression of NDR1 in tumor tissue was relatively lower than that in normal tissues and was positively related to a lower survival rate. NDR1 could markedly reduce the proliferation and colony formation of U87 and U251. Furthermore, the results of flow cytometry showed that NDR1 led to cell cycle arrest at the G1 phase. Tumor growth was also inhibited in xenograft nude mouse models in NDR1-overexpression group. Western blotting and immunofluorescence showed that NDR1 could integrate with and phosphorylate YAP at S127 site. Meanwhile, NDR1 could mediate apoptosis process.@*CONCLUSION@#In summary, our findings point out that NDR1 functions as a tumor suppressor in GBM. NDR1 is identified as a novel regulator of YAP, which gives us an in-depth comprehension of the Hippo signaling pathway.

Complex structures and diverse functions of nuclear bodies: a review / 生物工程学报

Nuclear bodies are membrane-free nuclear substructures that are localized in the mammalian nuclear matrix region. They are multiprotein complexes that recruit other proteins to participate in various cellular activities, such as transcription, RNA splicing, epigenetic regulation, tumorigenesis and antiviral defense. It is of great significance to clarify the functions and regulatory mechanisms of nuclear bodies to probe related diseases and virus-host interactions. This review takes several nuclear bodies associated proteins as examples, summarizes the formation process, structure and functions of nuclear bodies, and focuses on their important roles in antiviral infection. It is expected to provide new insight into host antiviral mechanisms.

Three-dimensional chromosome conformation capture and its derived technologies / 生物工程学报

Linear chromatin is compacted into eukaryotic nucleus through a complex and multi-layered architecture. Consequently, chromatin conformation in a local or long-distance manner is strongly correlated with gene expression. Chromosome conformation capture (3C) technology, together with its variants like 4C/5C/Hi-C, has been well developed to study chromatin looping and whole genome structure. In this review, we introduce new technologies including chromosome capture combined with immunoprecipitation, nuclei acid-based hybridization, single cell and genome sequencing, as well as their application.

Advances in three-dimensional genomics / 生物工程学报

Three-dimensional (3D) genomics is an emerging discipline that studies the 3D spatial structure and function of genomes, focusing on the 3D spatial conformation of genome sequences in the nucleus and its biological effects on biological processes such as DNA replication, DNA recombination and gene expression regulation. The invention of chromosome conformation capture (3C) technology speeds up the research on 3D genomics and its related fields. Furthermore, the development of 3C-based technologies, such as the genome-wide chromosome conformation capture (Hi-C) and chromatin interaction analysis using paired-end tag sequencing (ChIA-PET), help scientists get insight into the 3D genomes of various species. Aims of 3D genomics are to reveal the spatial genome organization, chromosomal interaction patterns, mechanisms underlying the transcriptional regulation and formation of biological traits of microorganism, plant, animal. Additionally, the identification of key genes and signaling pathways associated with biological processes and disease via chromosome 3C technology boosts the rapid development of agricultural science, life science and medical science. This paper reviews the research progress of 3D genomics, mainly in the concept of 3D genomics, the development of chromosome 3C technologies and their applications in agricultural science, life science and medical science, specifically in the field of tumor.

Research progress in Lamins in malignant tumors / 中南大学学报(医学版)

Changes in nuclear morphology are common in malignant tumors, but the underlying molecular mechanisms remain poorly understood. Lamins is involved in supporting nuclear structure, and the expression of Lamins is the molecular basis for nuclear morphological changes during tumor progression. In recent years, the research on the relationship between Lamins and malignant tumors has made great progress. Lamins is of great value in the diagnosis, treatment, and prognosis of various malignant tumors.

Nucleus translocation of membrane/cytoplasm proteins in tumor cells / 浙江大学学报·医学版

Proteins are the physical basis of life and perform all kinds of life activities. Proteins have different orientations and function in different tissues. The same protein, located in different subcellular regions, can perform different and even opposite functions. Both functional and structural proteins are capable of undergoing re-localization which can directly or indirectly participate in signal transduction. Due to abnormal transduction of signals during carcinogenesis, the proteins originally expressed in the cytoplasm are translocated into the nucleus and lead to functional changes in the tumor tissue. The changes of protein localization are affected by many factors, including the interaction between proteins, expression level of proteins and the cleaved intracellular domain of transmembrane protein.

Expression of EGR1 gene and location of EGR1 protein in differentiation of bovine skeletal muscle-derived satellite cells / 中国应用生理学杂志

OBJECTIVE@#To investigate the expression of EGR1 gene and the localization of EGR1 protein in bovine skeletal muscle-derived satellite cells (MDSCs), as well as to investigate the mechanism that EGR1 protein enters the nucleus.@*METHODS@#Bovine MDSCs were cultured in differentiation medium for 1 day, 3 days and 5 days, respectively, and each group was triplicate. The expression of EGR1 gene and the localization of EGR1 protein were studied at different differentiation period in MDSCs by qRT-PC and Western blot. Moreover, the changes on the expression of endogenous EGR1 gene and EGR1 proteins were explored by CRISPRi, site-directed mutagenesis and laser confocal method.@*RESULTS@#The results from the qRT-PCR and Western blot showed that the expressions of EGR1 gene on transcription level and translation level were significantly higher in differentiated cells than those in undifferentiated cells. The highest expression was found on the third day after the differentiation, and then began to decline. Immunofluorescence assays showed that EGR1 proteins were preferentially expressed in differentiated MDSCs, and increased along with the increase of number of myotubes. Confocal observation revealed that some EGR1 proteins were transferred into the nucleus in the differentiation of cells, however, the EGR1 proteins would not be detected in the differentiated MDSCs nuclei if a site directed mutagenesis (serine) on EGR1 protein occurred.@*CONCLUSION@#During the differentiation of bovine skeletal muscle satellite cells, the transcriptional level of EGR1 gene is increased, and some EGR1 proteins are transferred into the nucleus. The serine phosphorylation at position 533 of the C terminal of EGR1 protein is necessary for the nucleus transfer.

Extract of Fructus Schisandrae chinensis Inhibits Neuroinflammation Mediator Production from Microglia via NF-κ B and MAPK Pathways / 中国结合医学杂志

OBJECTIVE@#To investigate the anti-neuroinflammation effect of extract of Fructus Schisandrae chinensis (EFSC) on lipopolysaccharide (LPS)-induced BV-2 cells and the possible involved mechanisms.@*METHODS@#Primary cortical neurons were isolated from embryonic (E17-18) cortices of Institute of Cancer Research (ICR) mouse fetuses. Primary microglia and astroglia were isolated from the frontal cortices of newborn ICR mouse. Different cells were cultured in specific culture medium. Cells were divided into 5 groups: control group, LPS group (treated with 1 μg/mL LPS only) and EFSC groups (treated with 1 μg/mL LPS and 100, 200 or 400 mg/mL EFSC, respectively). The effect of EFSC on cells viability was tested by methylthiazolyldiphenyltetrazolium bromide (MTT) colorimetric assay. EFSC-mediated inhibition of LPS-induced production of pro-inflammatory mediators, such as nitrite oxide (NO) and interleukin-6 (IL-6) were quantified and neuron-protection effect against microglia-mediated inflammation injury was tested by hoechst 33258 apoptosis assay and crystal violet staining assay. The expression of pro-inflammatory marker proteins was evaluated by Western blot analysis or immunofluorescence.@*RESULTS@#EFSC (200 and 400 mg/mL) reduced NO, IL-6, inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2) expression in LPS-induced BV-2 cells (P<0.01 or P<0.05). EFSC (200 and 400 mg/mL) reduced the expression of NO in LPS-induced primary microglia and astroglia (P<0.01). In addition, EFSC alleviated cell apoptosis and inflammation injury in neurons exposed to microglia-conditioned medium (P<0.01). The mechanistic studies indicated EFSC could suppress nuclear factor (NF)-?B phosphorylation and its nuclear translocation (P<0.01). The anti-inflammatory effect of EFSC occurred through suppressed activation of mitogen-activated protein kinase (MAPK) pathway (P<0.01 or P<0.05).@*CONCLUSION@#EFSC acted as an anti-inflammatory agent in LPS-induced glia cells. These effects might be realized through blocking of NF-κB activity and inhibition of MAPK signaling pathways.

Nuclei ultrastructural changes of C6/36 cells infected with virus dengue type 2 / Cambios ultraestructurales en núcleos de células C6/36 infectadas con virus dengue de tipo 2

ABSTRACT Introduction: Dengue virus replication has been considered mainly cytoplasmic, however, studies indicate that some flaviviruses may use the intranuclear pathway as part of the machinery that the virus uses to increase infection capacity in the host cell. This paper describes alterations at nuclear level in the cell infected with dengue, which are likely involved in the virus replication processes. Objective: This paper addresses the ultrastructural observations of C6/36 cells of the Aedes albopictus mosquito infected with dengue virus type 2. Materials and methods: C6/36 cells were infected in culture medium with the serum of a patient positively diagnosed for dengue 2. Subsequently, the cells were incubated for 10 days and the cytopathic effect was assessed. The cells were processed for immunofluorescence assays and transmission electron microscopy. Results: The immunofluorescence assays confirmed the presence of viral protein E associated with cellular syncytia in the culture. In the ultrastructural study, the infected cells showed vesicular-tubular structures and dilated cisterns of the endoplasmic reticulum at the cytoplasmic level. Viral particles were found exclusively in cytoplasm localized within the vacuoles. Nuclei of cellular syncytia showed membrane structures arranged in a circular shape and, in some cases, these syncytia displayed lysis; in no case viral particles were observed at the nuclear level. Conclusions: The ultrastructural alterations of nuclei in cells infected with the dengue virus using electron microscopy techniques had not been reported before, as far as we know. It is likely that such modifications are associated with replicative processes at an intranuclear level as an alternate replication mechanism.

RESUMEN Introducción. La replicación del virus del dengue se ha considerado principalmente citoplásmica; sin embargo, en diversos estudios se ha informado que algunos flavivirus pueden utilizar factores intranucleares como parte de la maquinaria que utilizan para aumentar la capacidad de infección en la célula huésped. En este trabajo se describen las alteraciones a nivel nuclear en células infectadas con dengue, probablemente involucradas en procesos de replicación viral. Objetivo. Presentar las observaciones ultraestructurales de células C6/36 de Aedes albopictus infectadas con el virus del dengue de tipo 2. Materiales y métodos. Se infectaron células C6/36 con suero de un paciente con diagnóstico de dengue 2; posteriormente, se mantuvieron en medio de cultivo durante 10 días y se evaluó el efecto citopático. Las células se procesaron para los ensayos de inmunofluorescencia y microscopía electrónica de transmisión, con el fin de hacer el estudio ultraestructural. Resultados. Los ensayos de inmunofluorescencia confirmaron la presencia de la proteína E viral asociada con sincitios celulares en el cultivo. En el estudio ultraestructural, las células infectadas tenían estructuras vesiculares y tubulares, y cisternas dilatadas del retículo endoplásmico en el citoplasma. Las partículas virales se encontraron exclusivamente en vacuolas localizadas en el citoplasma. Los núcleos de los sincitios celulares contenían estructuras de membrana dispuestas en forma circular y, en algunos casos, dichos sincitios presentaban lisis. En ningún caso se observaron partículas virales en el núcleo. Conclusiones. No se habían reportado alteraciones ultraestructurales en los núcleos de células infectadas con el virus del dengue detectadas mediante técnicas de microscopia electrónica. Es probable que tales modificaciones estén asociadas con procesos intranucleares de replicación como un mecanismo alternativo.

Functions of lamin B1 and the new progress of its roles in neurological diseases and tumors / 生物工程学报

Lamin B1 is one of the essential members of the nuclear lamina protein family. Its main function is to maintain the integrity of nuclear skeleton, as well as to participate in the cell proliferation and aging by affecting the chromosome distribution. gene expression, and DNA damage repair. The abnormal expression of lamin B1 is related to certain diseases, including neurological diseases [e.g. neural tube defects (NDTs), adult-onset autosomal dominant leukodystrophy (ADLD)] and tumors (e.g. pancreatic cancer). It is also a potential tumor marker as well as drug target. Further research on lamin B1 will help people understand the molecular mechanism of the emergence and development of neural system diseases and tumors, and define a new future in drug target.