MicroRNAs (miRNAs) are a set of non-coding small RNA molecules in control of gene expression at posttranscriptional/translational level. They not only play crucial roles in normal developmental progress, but also are commonly dysregulated in human diseases, including cancer. MiR-200 is a family of tumor suppressor miRNAs consisting of five members, which are significantly involved in inhibition of epithelial-to-mesenchymal transition (EMT), repression of cancer stem cells (CSCs) self-renewal and differentiation, modulation of cell division and apoptosis, and reversal of chemoresistance. In this article, we summarize the latest findings with regard to the tumor suppressor signatures of miR-200 and the regulatory mechanisms of miR-200 expression. The collected evidence supports that miR-200 is becoming a new star miRNA in study of human cancer.

The intercalation of large organic ammonium ions (tetramethylammonium ions (TMA + ), tetraethylammonium ions (TEA + ), tetrapropylammonium ions (TPA + ), and tetrabutylammonium ions (TBA + )) into layered graphite oxide (GO) was systematically investigated. The intercalation reactions were completed at 25 °C after 3 days, and stable colloidal suspensions were obtained at TAAl/Hs ) 5 (molar ratio of tetraalkylammonium ions (TAA + ) over exchangeable protons in GO). The sediments after centrifuging the colloidal suspensions showed amorphous phase X-ray diffraction patterns, indicating that exfoliation of the layered structure into nanosheets took place in the suspension. When the sediments were dried at 70 °C for 3 days, layered structures of TAA + -intercalated GO materials with basal spacings of 1.56, 1.67, 1.84, and 2.37 nm, respectively, appeared. The basal spacing of the layered compounds decreased with a decrease of relative humidity during drying. When the dried TAA + -intercalated GO compounds were exposed to a humid saturated atmosphere, the basal spacing increased gradually, finally becoming an amorphous structure. The maximum saturation of intercalated TAA + ions into GO decreased with the increase in alkyl chain length. When the TAA + -intercalated materials were washed with distilled water and acid-treated, a process of deintercalation of TAA + ions from the interlayer occurred. A schematic model for the deintercalation-intercalation involving a exfoliation process is proposed. The layered structure of TAA +intercalated GO materials is discussed in terms of the dimension of the GO layer and the sizes of H2O molecules and TAA + ions.

Background:The alveolar compartment is a procoagulant antifibrinolytic environment in acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). A study was undertaken to test the hypothesis that the alveolar epithelium can initiate intra-alveolar coagulation by expressing active tissue factor (TF). Methods: Using an in vitro cell surface TF assay and TF ELISA, the activity and production of TF in cultured alveolar epithelial (A549) cells following exposure to cytomix (tumour necrosis factor a, interleukin 1b and interferon c) was measured. TF gene transcription was measured by semi-quantitative reverse-transcription PCR. Immunohistochemistry for TF was performed on lung sections from patients with ARDS and controls. TF protein levels were measured by ELISA in undiluted pulmonary oedema fluid from patients with ALI/ARDS and compared with control patients with hydrostatic pulmonary oedema. Results: TF activity, mRNA and protein levels increased in A549 cells after stimulation with cytomix. Increased TF activity was also seen in A549 cells following incubation with pulmonary oedema fluid from patients with ALI/ARDS. Immunohistochemistry for TF in human lung tissue from patients with ARDS showed prominent TF staining in alveolar epithelial cells as well as intra-alveolar macrophages and hyaline membranes. TF antigen levels in oedema fluid (median 37 113 (IQR 14 956-73 525) pg/ml) were significantly higher than in plasma (median 336 (IQR 165-669) pg/ml, p,0.001) in patients with ALI/ARDS, and TF procoagulant activity in oedema fluid was much higher than in plasma of these patients. Higher plasma levels were associated with mortality. Conclusions: The alveolar epithelium is capable of modulating intra-alveolar coagulation through upregulation of TF following exposure to inflammatory stimuli and may contribute to intra-alveolar fibrin deposition in ARDS.

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This paper describes the synthesis and characterization of single-layer graphene oxide-periodic mesoporous silica sandwich nanocomposites. Through a comprehensive exploration of the synthesis conditions, it has proven possible to create the first example of a graphene oxide-periodic mesoporous silica nanocomposite in which hexagonal symmetry PMS film grows on both sides of the graphene oxide sheets with the mesoporous channels vertically aligned with respect to the graphene oxide surface. The formation of this novel architecture is found to be very sensitive to pH, the ratio of surfactant template to graphene oxide, the amount of silica precursor, and the temperature of the synthesis. On the basis of the collected data of a multi-technique analysis, it is proposed that the mode of formation of the nanocomposite involves the co-assembly of silicate-surfactant admicelles on opposite sides of graphene oxide platelets acting thereby as a template for growth of vertical mesopores off the platelet surface. These composites showed semiconductive behavior with electrical conductivity sensitively responding to analyte vapor exposure. The discovery of graphene oxide-periodic mesoporous silica sandwich nanocomposites will provide new opportunities for research that exploits the synergism of the graphene oxide and periodic mesoporous silica parts.

RECQL4 is a human RecQ helicase which is mutated in approximately two-thirds of individuals with Rothmund-Thomson syndrome (RTS), a disease characterized at the cellular level by chromosomal instability. BLM and WRN are also human RecQ helicases, which are mutated in Bloom and Werner's syndrome, respectively, and associated with chromosomal instability as well as premature aging. Here we show that primary RTS and RECQL4 siRNA knockdown human fibroblasts accumulate more H(2)O(2)-induced DNA strand breaks than control cells, suggesting that RECQL4 may stimulate repair of H(2)O(2)-induced DNA damage. RTS primary fibroblasts also accumulate more XRCC1 foci than control cells in response to endogenous or induced oxidative stress and have a high basal level of endogenous formamidopyrimidines. In cells treated with H(2)O(2), RECQL4 co-localizes with APE1, and FEN1, key participants in base excision repair. Biochemical experiments indicate that RECQL4 specifically stimulates the apurinic endonuclease activity of APE1, the DNA strand displacement activity of DNA polymerase beta, and incision of a 1- or 10-nucleotide flap DNA substrate by Flap Endonuclease I. Additionally, RTS cells display an upregulation of BER pathway genes and fail to respond like normal cells to oxidative stress. The data herein support a model in which RECQL4 regulates both directly and indirectly base excision repair capacity.

An increasing number of microRNAs (miRNAs) have been shown to play crucial regulatory roles in the process of plant development. Here, we used high-throughput sequencing combined with computational analysis to characterize miRNAomes from the ovules of wild-type upland cotton and a fiberless mutant during fiber initiation. Comparative miRNAome analysis combined with northern blotting and RACE-PCR revealed seven fiber initiation-related miRNAs expressed in cotton ovules and experimentally validated targets of these miRNAs are involved in different cellular responses and metabolic processes, including transcriptional regulation, auxin and gibberellin signal transduction, actin bundles, and lignin biosynthesis. This paper describes a complex regulatory network consisting of these miRNAs expressed in cotton ovules to coordinate fiber initiation responses. In addition, 36 novel miRNAs and two conserved miRNAs were newly identified, nearly doubling the number of known cotton miRNA families to a total of 78. Furthermore, a chromatin remodeling complex subunit and a pre-mRNA splicing factor are shown for the first time to be miRNA targets. To our knowledge, this study is the first systematic investigation of fiber initiation-related miRNAs and their targets in the developing cotton ovule, deepening our understanding of the important regulatory functions of miRNAs in cotton fiber initiation.

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