61 research outputs found
Circular RNA circNOL10 Inhibits Lung Cancer Development by Promoting SCLM1-Mediated Transcriptional Regulation of the Humanin Polypeptide Family
circNOL10 is a circular RNA expressed at low levels in lung cancer, though its functions in lung cancer remain unknown. Here, the function and molecular mechanism of circNOL10 in lung cancer development are investigated using in vitro and in vivo studies, and it is shown that circNOL10 significantly inhibits the development of lung cancer and that circNOL10 expression is co‐regulated by methylation of its parental gene Pre‐NOL10 and by splicing factor epithelial splicing regulatory protein 1 (ESRP1). circNOL10 promotes the expression of transcription factor sex comb on midleg‐like 1 (SCML1) by inhibiting transcription factor ubiquitination and thus also affects regulation of the humanin (HN) polypeptide family by SCML1. circNOL10 also affects mitochondrial function through regulating the humanin polypeptide family and affecting multiple signaling pathways, ultimately inhibiting cell proliferation and cell cycle progression, and promoting the apoptosis of lung cancer cells, thereby inhibiting lung cancer development. This study investigates the functions and molecular mechanisms of circNOL10 in the development of lung cancer and reveals its involvement in the transcriptional regulation of the HN polypeptide family by SCML1. The results also demonstrate the inhibitory effect of HN on lung cancer cells growth. These findings may identify novel targets for the molecular therapy of lung cancer
Sodium aescinate inhibits microglia activation through NF-κB pathway and exerts neuroprotective effect
Background: Microglia are resident immune cells of the central nervous system that sense environmental changes and maintain central nervous system homeostasis. Dysfunctional microglia produce toxic mediators that lead to neuronal death. Recent studies suggest that Sodium Aescinate has a neuroprotective effect. However, it is unclear whether Sodium Aescinate exerts neuroprotective effects by inhibiting activation of microglia.Method: Traumatic brain injury and lipopolysaccharide neuroinflammation model were used to evaluate the microglia activation in vivo. BV2 and primary microglia cells were used to assess the microglia activation in vitro. Molecular docking technique was used to predict the binding energy of Sodium Aescinate to NF-κB signaling pathway proteins.Result: Sodium Aescinate inhibited microglial activation in-vivo and in-vitro. Sodium Aescinate inhibited the activation of microglia in Traumatic brain injury and lipopolysaccharide mouse models. Sodium Aescinate also inhibited the expression of inflammatory proteins in BV2 and primary microglia cells. Western blot experiment showed that SA inhibited the activation of NF-κB pathway in BV2 and primary microglia cells. Molecular docking results also showed that Sodium Aescinate had a better affinity with the core protein of the NF-κB pathway. Western blot identified that SA inhibited activation of NF-κB pathway. In Traumatic brain injury model and conditioned medium experiment, Sodium Aescinate pretreatment inhibited inflammation and protected neuron.Conclusion: Our study confirmed that the protection effects of Sodium Aescinate on neurons by inhibiting microglia activation through NF-κB pathway
Phylogenetic Diversity and Ecological Pattern of Ammonia-oxidizing Archaea in the Surface Sediments of the Western Pacific
The phylogenetic diversity of ammonia-oxidizing archaea (AOA) was surveyed in the surface sediments from the northern part of the South China Sea (SCS). The distribution pattern of AOA in the western Pacific was discussed through comparing the SCS with other areas in the western Pacific including Changjiang Estuary and the adjacent East China Sea where high input of anthropogenic nitrogen was evident, the tropical West Pacific Continental Margins close to the Philippines, the deep-sea methane seep sediments in the Okhotsk Sea, the cold deep sea of Northeastern Japan Sea, and the hydrothermal field in the Southern Okinawa Trough. These various environments provide a wide spectrum of physical and chemical conditions for a better understanding of the distribution pattern and diversities of AOA in the western Pacific. Under these different conditions, the distinct community composition between shallow and deep-sea sediments was clearly delineated based on the UniFrac PCoA and Jackknife Environmental Cluster analyses. Phylogenetic analyses showed that a few ammonia-oxidizing archaeal subclades in the marine water column/sediment clade and endemic lineages were indicative phylotypes for some environments. Higher phylogenetic diversity was observed in the Philippines while lower diversity in the hydrothermal vent habitat. Water depth and possibly with other environmental factors could be the main driving forces to shape the phylogenetic diversity of AOA observed, not only in the SCS but also in the whole western Pacific. The multivariate regression tree analysis also supported this observation consistently. Moreover, the functions of current and other climate factors were also discussed in comparison of phylogenetic diversity. The information collectively provides important insights into the ecophysiological requirements of uncultured ammonia-oxidizing archaeal lineages in the western Pacific Ocean
A flexible topological flank modification method based on polynomial interpolation function
Topological modification of gear surface is used to achieve better meshing transmission performance and accuracy. However, in the traditional gear modification grinding process, the topological modified tooth surface is usually simplified to the control of profile modification and lead modification, which is difficult to achieve the coincidence of machining and design. To solve this problem, a flexible topology flank modification method based on polynomial interpolation function is proposed in this paper. Based on the gear meshing principle and polynomial interpolation technology, the method realizes a topological modification of the gear by controlling multiple axes’s position on the machine tool. Firstly, a gear grinding model of worm grinding wheel with controllable grinding precision is established. Then the axial, radial and tangential motions of worm grinding wheel is expressed as fifth order polynomials, and the polynomial coefficients is optimized by particle swarm optimization algorithm. Finally, numerical simulation was used to compare the proposed method with the sensitivity matrix method, and the results showed that the proposed method had better optimization effect. The new flexible topological modification method can realize the topological modification machining by controlling the motion of each axis of the tool, and the problem that the topological modification machining does not match the design is solved
Research on Generating Gear Grinding Machining Error Based on Mapping Relationship between Grinding Wheel Surface and Tooth Flank
This paper proposes a method to study the machining error when one is generating gear grinding based on the mapping relationship between the grinding wheel surface and the tooth flank. The profile of the grinding wheel after grinding is collected, and the theoretical tooth flank is derived according to a model of generating gear grinding. By comparing the normal deviation of the theoretical tooth flank with the measured tooth flank, the machining error characteristics are identified. Firstly, the mathematical model of generating gear grinding is established according to a multi-body theory and coordinate transformation. Secondly, the experiments of the lead modification for helical gear were performed on a YW7232 CNC gear grinding machine. The tooth flank twist compensation function was turned off in experiments No. 1–No. 3, and it was turned on in experiments No. 4–No. 6, while the other process parameters kept the same. Then, the corresponding theoretical tooth flank data were derived from the grinding wheel surface which were measured using the laser profilometer LJ-V7000. Finally, the machining error characteristics were obtained by analyzing the difference between the theoretical and measured tooth flank deviations. The result of this paper can provide theoretical and practical references for the improvement of the gear grinding accuracy and gear modification design
Low Long Noncoding RNA Growth Arrest-Specific Transcript 5 Expression in the Exosomes of Lung Cancer Cells Promotes Tumor Angiogenesis
Angiogenesis plays a key role in the development and progression of lung cancer. Recent studies have found that tumor cells can stimulate angiogenesis by secreting exosomes, which contain many long noncoding RNAs (lncRNAs), some of which are important for the development of lung cancer. However, the roles and mechanisms of exosomal lncRNAs in lung cancer angiogenesis have not yet been reported. In this study, lung cancer in mice was induced by urethane; we found that growth arrest specific 5 (GAS5) was lowly expressed in the serum exosomes and lung cancer tissues of mice with lung cancer. And there was a significant positive correlation between GAS5 expression in serum exosomes and lung cancer tissues. Furthermore, GAS5 was lowly expressed in human lung cancer tissues, lung cancer cells, and cells culture supernatant exosomes. The exosomes of lung cancer cells promoted human umbilical vein endothelial cells (HUVECs) proliferation and tube formation and inhibited their apoptosis. GAS5 overexpression in lung cancer cells increased GAS5 level in cell culture supernatant exosomes. And the exosomes of lung cancer cells containing high GAS5 level inhibited HUVECs proliferation and tube formation and increased their apoptosis. In addition, we found that GAS5 competitively bound miRNA-29-3p with phosphatase and tensin homolog (PTEN), upregulating PTEN mRNA and protein expression, and inhibited level of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PI3K) and serine/threonine kinase 1 (AKT) phosphorylation in HUVECs. Overall, our results suggest that exosomal GAS5 could be a new therapeutic target for lung cancer which inhibits angiogenesis
Low Long Noncoding RNA Growth Arrest-Specific Transcript 5 Expression in the Exosomes of Lung Cancer Cells Promotes Tumor Angiogenesis
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