Astragaloside IV alleviates atherosclerosis through targeting circ_0000231/miR-135a-5p/CLIC4 axis in AS cell model in vitro

Molecular and Cellular Biochemistry - Non-coding RNAs (ncRNAs) have shown to act as crucial mediators in atherosclerosis (AS) development. The purpose of our study was to explore the role of...     

Circ_0026579 alleviates LPS-induced WI-38 cells inflammation injury in infantile pneumonia

Circular RNA (circRNA) represents an important regulator in infantile pneumonia progression. To clarify the role of circ_0026579 in this disease, LPS was used to treat WI-38 cells to mimic inflammation injury. The levels of inflammatory factors were determined by ELISA assay. Cell proliferation and apoptosis were measured by MTT assay, EdU staining and flow cytometry. The protein levels of cyclinD1, cleaved-caspase-3 and insulin-like growth factor 2 (IGF2) were examined using Western blot analysis. Cell oxidative stress was assessed by detecting MDA level and SOD activity. The expression of circ_0026579, miR-24-3p and IGF2 were analyzed using quantitative real-time PCR, and the interaction between miR-24-3p and circ_0026579 or IGF2 was confirmed by dual-luciferase reporter assay and RIP assay. LPS induced inflammation in WI-38 cells. Circ_0026579 expression was promoted in LPS-induced WI-38 cells, and its knockdown alleviated LPS-induced WI-38 cells inflammation. MiR-24-3p was sponged by circ_0026579, and its expression was reduced by LPS. MiR-24-3p inhibitor reversed the regulation of circ_0026579 knockdown on LPS-induced WI-38 cells inflammation. IGF2 was targeted by miR-24-3p, and its expression could be enhanced by LPS. MiR-24-3p relieved the inflammation of WI-38 cells which could be abolished by IGF2 overexpression. Circ_0026579 positively regulated IGF2 expression through sponging miR-24-3p. Circ_0026579 knockdown alleviated LPS-induced WI-38 cells inflammation by miR-24-3p/IGF2 axis, suggesting that circ_0026579 might contribute to infantile pneumonia progression.     

Rapid assessment of repair of ultraviolet DNA damage with a modified host-cell reactivation assay using a luciferase reporter gene and correlation with polymorphisms of DNA repair genes in normal human lymphocytes

As DNA repair plays an important role in genetic susceptibility to cancer, assessment of the DNA repair phenotype is critical for molecular epidemiological studies of cancer. In this report, we compared use of the luciferase (luc) reporter gene in a host-cell reactivation (HCR) (LUC) assay of repair of ultraviolet (UV) damage to DNA to use of the chloramphenicol (cat) gene-based HCR (CAT) assay we used previously for case-control studies. We performed both the assays on cryopreserved lymphocytes from 102 healthy non-Hispanic white subjects. There was a close correlation between DNA repair capacity (DRC) as measured by the LUC and CAT assays. Although these two assays had similar variation, the LUC assay was faster and more sensitive. We also analyzed the relationship between DRC and the subjects' previously determined genotypes for four polymorphisms of two nucleotide-excision repair (NER) genes (in intron 9 of xeroderma pigmentosum (XP) C and exons 6, 10 and 23 of XPD) and one polymorphism of a base-excision repair gene in exon 10 of X-ray complementing group 1 (XRCC1). The DRC was significantly lower in subjects homozygous for one or more polymorphisms of the two NER genes than in subjects with other genotypes (P=0.010). In contrast, the polymorphic XRCC1 allele had no significant effect on DRC. These results suggest that the post-UV LUC assay measures NER phenotype and that polymorphisms of XPC and XPD genes modulate DRC. For population studies of the DNA repair phenotype, many samples need to be evaluated, and so the LUC assay has several advantages over the CAT assay: the LUC assay was more sensitive, had less variation, was not radioactive, was easier to perform, and required fewer cryopreserved cells. These features make the LUC-based HCR assay suitable for molecular epidemiological studies.     

Heterogeneous activity causes a nonlinear increase in the group energy use of ant workers isolated from queen and brood

Increasing evidence has shown that the energy use of ant colonies increases sublinearly with colony size so that large colonies consume less per capita energy than small colonies. It has been postulated that social environment (e.g., in the presence of queen and brood) is critical for the sublinear group energetics, and a few studies of ant workers isolated from queens and brood observed linear relationships between group energetics and size. In this paper, we hypothesize that the sublinear energetics arise from the heterogeneity of activity in ant groups, that is, large groups have relatively more inactive members than small groups. We further hypothesize that the energy use of ant worker groups that are allowed to move freely increases more slowly than the group size even if they are isolated from queen and brood. Previous studies only provided indirect evidence for these hypotheses due to technical difficulties. In this study, we applied the automated behavioral monitoring and respirometry simultaneously on isolated worker groups for long time periods, and analyzed the image with the state‐of‐the‐art algorithms. Our results show that when activity was not confined, large groups had lower per capita energy use, a lower percentage of active members, and lower average walking speed than small groups; while locomotion was confined, however, the per capita energy use was a constant regardless of the group size. The quantitative analysis shows a direct link between variation in group energy use and the activity level of ant workers when isolated from queen and brood.     

Expression of human VEGF165 in silkworm (Bombyx mori L.) by using a recombinant baculovirus and its bioactivity assay

Silkworm larva has a lot of advantages as a "biofactory" to produce recombinant protein. A recombinant baculovirus, carrying cDNA encoding the 165 amino-acid long isoform of human vascular endothelial growth factor (VEGF) was successfully constructed for the large-scale production of this protein using silkworms as an in vivo host. The fifth-instar silkworm larvae were inoculated with the recombinant virus. Time-course expression analysis indicated that the expression level was highest at around 80 h post-infection and the recombinant protein was found mainly in the haemolymph. Therefore, the hemolymph was collected from the infected larvae and the recombinant protein was purified by using Nickel affinity chromatography under native condition. The expression level was estimated to be as high as approximately 426 microg per larva. Furthermore, the recombinant protein was characterized and was found biologically active in inducing endothelial cell proliferation in vitro.     

TriboPump: A Low‐Cost,Hand‐Powered Water Disinfection System

Water disinfection at the point of use (POU) has enormous social and economic significance, especially for rural areas or catastrophes. To tackle the requirements of power independence and cost control in such applications, the concept of TriboPump is proposed, which is a low‐cost, hand‐powered water disinfection system. The system consists of three functional parts: a tubular coaxial‐electrode copper ionization cell (CECIC) as the disinfection device, a disk triboelectric nanogenerator (D‐TENG) as the power source, and a coaxial mechanical structure including the water pump. The adoption of D‐TENG can make the system adaptive to varying system resistances without additional power management circuits. Moreover, the integration of CECIC and TENG can successfully turn their intrinsic limitations into advantages and a synergic effect is achieved. With the integrated design, the system can effectively disinfect the water while pumping it solely by hand power. The cost estimate of the whole system can be as low as $10 for a 2‐year service. It is believed that the whole system design provides a feasible one‐stop and cost‐efficient solution for POU water pumping and disinfection, which will ideally be suitable the rural areas or sudden‐onset catastrophes.     

In vitro expression levels of cell-cycle checkpoint proteins are associated with cellular DNA repair capacity in peripheral blood lymphocytes: a multivariate analysis

DNA repair should occur after cells sense DNA damage signals and undergo cell-cycle arrest to provide sufficient time for DNA repair, and suboptimal DNA repair capacity (DRC) in peripheral lymphocytes has been suggested as a cancer susceptibility marker. Numerous studies showed a functional link between DNA damage sensing, cell-cycle checkpoint, and DNA repair. We hypothesized that in vitro cell-cycle checkpoint-related protein expression levels in stimulated lymphocytes predict DRC levels. To test this hypothesis, we performed the host-cell reactivation assay for DRC by transfecting stimulated peripheral blood lymphocytes from 120 normal donors with transient expression plasmids damaged by benzo[a]pyrene diol epoxide (BPDE). The same cells were assessed for protein expression induction of eight cell-cycle checkpoint-related genes using the reverse-phase protein lysate microarray assay. In multivariate linear regression analysis adjusting for age, sex, blastogenic rate, and sample storage duration, the association between DRC and expression levels of cell-cycle checkpoint-related proteins induced by BPDE-adducts was statistically significant for p27, CCND1, ATM, and MDM2 (P = 0.00, 0.03, 0.03, and 0.03, respectively), borderline for p73 and p21 (P = 0.07 and 0.09, respectively), but not for p53 and p16 (P = 0.13 and 0.18, respectively). Because the relative expression levels of all these eight proteins were highly correlated, we further performed the principal component analysis and identified ATM as the most important predictor of DRC, followed by MDM2 and p27. Our results provide population-based in vitro evidence demonstrating that cell-cycle checkpoint-related proteins play essential roles in regulating DNA repair, at least in unaffected human peripheral blood lymphocytes. Further studies are warranted to investigate the role of interindividual variation in the expression levels of these proteins in cancer susceptibility.     

抗菌肽构效关系及其表达策略研究进展

抗菌肽(antim icrobial peptides)是一类具有抗菌活性短肽的总称,广泛分布于原核生物与包括人类在内的真核生物体内,是宿主免疫防御系统中的重要组成部分。研究表明,抗菌肽除具有抗病毒、抗细菌、抗真菌作用外,还具有抗肿瘤作用。现从抗菌肽的结构特点与抗菌机制出发,对其构效关系及表达策略进行综述。     

An engineered approach to stem cell culture: automating the decision process for real-time adaptive subculture of stem cells

Current cell culture practices are dependent upon human operators and remain laborious and highly subjective, resulting in large variations and inconsistent outcomes, especially when using visual assessments of cell confluency to determine the appropriate time to subculture cells. Although efforts to automate cell culture with robotic systems are underway, the majority of such systems still require human intervention to determine when to subculture. Thus, it is necessary to accurately and objectively determine the appropriate time for cell passaging. Optimal stem cell culturing that maintains cell pluripotency while maximizing cell yields will be especially important for efficient, cost-effective stem cell-based therapies. Toward this goal we developed a real-time computer vision-based system that monitors the degree of cell confluency with a precision of 0.791±0.031 and recall of 0.559±0.043. The system consists of an automated phase-contrast time-lapse microscope and a server. Multiple dishes are sequentially imaged and the data is uploaded to the server that performs computer vision processing, predicts when cells will exceed a pre-defined threshold for optimal cell confluency, and provides a Web-based interface for remote cell culture monitoring. Human operators are also notified via text messaging and e-mail 4 hours prior to reaching this threshold and immediately upon reaching this threshold. This system was successfully used to direct the expansion of a paradigm stem cell population, C2C12 cells. Computer-directed and human-directed control subcultures required 3 serial cultures to achieve the theoretical target cell yield of 50 million C2C12 cells and showed no difference for myogenic and osteogenic differentiation. This automated vision-based system has potential as a tool toward adaptive real-time control of subculturing, cell culture optimization and quality assurance/quality control, and it could be integrated with current and developing robotic cell cultures systems to achieve complete automation.