摘要:
In this research, we carried out a tritrophic bioassay to assess the potential effect of Cry1Ab-expressing rice on the foraging behavior of the common wolf spider Pardosa pseudoannulata and its underlying molecular mechanism. Results indicated the Bt-containing spiders expressed a higher foraging range when compared to controls. The high throughput de novo transcriptome sequencing was further carried out for central nervous system (CNS) of P. pseudoannulata with and without Cry1Ab intake. We obtained 120, 985 unigenes with a mean length of 529.73 bp. Functional analysis of differentially expressed genes (DEGs) showed the expression levels of genes related to energy metabolism were changed in response to Cry1Ab, which may contribute to a more active foraging behavior. In addition, some DEGs also have a function related to metal ion binding, implying a potential influence on metal ions-dependent reactions. This may be associated with Cry1Ab resistance mechanism in the spider.
摘要:
Angiostrongylus cantonensis has been the only parasite among Angiostrongylidae to cause human central nervous system infection characterized by eosinophilic meningitis or meningoencephalitis. The mechanism of the extensive neurological impairments of hosts caused by A. cantonensis larvae remains unclear. The aim of the present study was to investigate apoptosis, necroptosis and autophagy in the brains of mice infected with A. cantonensis, which will be valuable for better understanding the pathogenesis of angiostrongyliasis cantonensis. Functional and histological neurological impairments of brain tissues from mice infected with A. cantonensis were measured by the Morris water maze test and haematoxylin and eosin (H&E) staining, respectively. The transcriptional and translational levels of apoptosis-, necroptosis- and autophagy-related genes were quantified by quantitative real-time polymerase chain reaction (RT-PCR), and assessed by western blot and immunohistochemistry (IHC) analysis. Apoptotic and necroptotic cells and their distributions in infected brain tissues were analysed by flow cytometry and transmission electron microscopy (TEM). Inflammatory response in the central nervous system deteriorated as A. cantonensis infection evolved, as characterized by abundant inflammatory cell infiltration underneath the meninges, which peaked at 21 days post-infection (dpi). The learning and memory capacities of the mice were significantly decreased at 14 dpi, indicating prominent impairment of their cognitive functions. Compared with those of the control group, the mRNA levels of caspase-3, -4, -6, and RIP3 and the protein levels of caspase-4, cleaved caspase-3, cleaved caspase-6, RIP3, and pRIP3 were obviously elevated. However, no changes in the mRNA or protein levels of FADD, Beclin-1 or LC3B were evident, indicating that apoptosis and necroptosis, but not autophagy, occurred in the brain tissues of mice infected with A. cantonensis. The quantitative RT-PCR, western blot, IHC, flow cytometry and TEM results further revealed the apoptotic and necroptotic microglia, astrocytes and neurons in the parenchymal and hippocampal regions of infected mice. To our knowledge, we showed for the first time that A. cantonensis infection causes the apoptosis and necroptosis of microglia and astrocytes in the parenchymal and hippocampal regions of host brain tissues, further demonstrating the pathogenesis of A. cantonensis infection and providing potential therapeutic targets for the management of angiostrongyliasis.
摘要:
The impact of Bacillus thuringiensis (Bt) toxin proteins on non-target predatory arthropods is not well understood at the cellular and molecular levels. Here, we investigated the potential effects of Cry1Ab expressing rice on fecundity of the wolf spider, Pardosa pseudoannulata, and some of the underlying molecular mechanisms. The results indicated that brown planthoppers (BPHs) reared on Cry1Ab-expressing rice accumulated the Cry toxin and that reproductive parameters (pre-oviposition period, post-oviposition stage, number of eggs, and egg hatching rate) of the spiders that consumed BPHs reared on Bt rice were not different from those that consumed BPHs reared on the non-Bt control rice. The accumulated Cry1Ab did not influence several vitellin (Vt) parameters, including stored energy and amino acid composition, during one generation. We considered the possibility that the Cry toxins exert their influence on beneficial predators via more subtle effects detectable at the molecular level in terms of gene expression. This led us to transcriptome analysis to detect differentially expressed genes in the ovaries of spiders exposed to dietary Cry1Ab and their counterpart control spiders. Eight genes, associated with vitellogenesis, vitellogenin receptor activity, and vitellin membrane formation were not differentially expressed between ovaries from the treated and control spiders, confirmed by qPCR analysis. We infer that dietary Cry1Ab expressing rice does not influence fecundity, nor expression levels of Vt-associated genes in P. pseudoannulata. (C) 2016 Published by Elsevier B.V.
摘要:
探讨了不同温度(25、30和35℃)对拟环纹豹蛛的捕食功能及寻找效应的影响。结果表明:拟环纹豹蛛对褐飞虱的捕食反应均符合Holling II 模型,其中在30℃下,拟环纹豹蛛对褐飞虱的控制效果最好,雌、雄成蛛对褐飞虱的捕食上限分别为100头和166.67头。在不同温度下捕食量有差异,但差异不显著(P>0.05),不同龄期拟环纹豹蛛随着褐飞虱密度增加寻找效应呈下降趋势。3龄、5龄幼蛛随着猎物的增多搜寻效应值呈急剧下降趋势,而雌、雄成蛛下降相对平缓。研究表明,雌雄成蛛的寻找效应比幼株的搜寻能力强。
摘要:
Conjugates of fatty acids and amines, including endocannabinoids, are known to play important roles as endogenous signaling molecules. Among these, the ethanolamine conjugate of the n-3 poly unsaturated long chain fatty acid (PUFA) docosahexaenoic acid (22:6n-3) (DHA) was shown to possess strong anti-inflammatory properties. Previously, we identified the serotonin conjugate of DHA, docosahexaenoyl serotonin (DHA-5-1-HT), in intestinal tissues and showed that its levels are markedly influenced by intake of n-3 PUFAs. However, its biological roles remain to be elucidated. Here, we show that DHA-5-HT possesses potent anti-inflammatory properties by attenuating the IL-23-IL-17 signaling cascade in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Transcriptome analysis revealed that DHA-5-HT down-regulates LPS-induced genes, particularly those involved in generating a CD4+ Th17 response. Hence, levels of PGE2, IL-6, IL-1 beta, and IL-23, all pivotal macrophage produced mediators driving the activation of pathogenic Th17 cells in a concerted way, were found to be significantly suppressed by concentrations as low as 100-500 nM DHA-5-HT. Furthermore, DHA-5-HT inhibited the ability of RAW264.7 cells to migrate and downregulated chemokines like MCP-1, CCL-20, and gene-expression of CCL-22 and of several metalloproteinases. Gene set enrichment analysis (GSEA) suggested negative overlap with gene sets linked to inflammatory bowel disease (IBD) and positive overlap with gene sets related to the Nrf2 pathway. The specific formation of DHA-5-HT in the gut, combined with increasing data underlining the importance of the IL-23-IL-17 signaling pathway in the etiology of many chronic inflammatory diseases merits further investigation into its potential as therapeutic compound in e.g. IBD or intestinal tumorigenesis. (C) 2016 Elsevier B.V. All rights reserved.
摘要:
The effects of three surfactants (Tween 80, saponin and monorhamnolipid) on the hydrolysis of alkali pretreated rice straw by low dosage of cellulase were studied. The results indicated that with a relatively low cellulase dosage (4 FPU g(-1) substrate), all surfactants were able to enhance the enzymatic hydrolysis, while the biosurfactant monorhamnolipid was demonstrated to be more active than Tween 80 and saponin. Monorhamnolipid at 0.006% increased reducing sugar yield by 23.15%, and the maximal sugar yield was obtained within half of the time compare to the control required. The cellulase losed 67% of its activity in the control, while the activity lost ratios were 31%similar to 43% in the presence of the surfactants. The surfactants addition did not affect the pH of the hydrolysis system. This study provides an opportunity of decreasing enzyme dosage in hydrolysis of agricultural solid waste rich in cellulose.
摘要:
Objective To reveal the effects and related mechanisms of chlorogenic acid (CGA) on intestinal glucose homeostasis. Methods Forty male Sprague-Dawley rats were randomly and equally divided into four groups: normal chow (NC), high-fat diet (HFD), HFD with low-dose CGA (20 mg/kg, HFD-LC), and HFD with high-dose CGA (90 mg/kg, HFD-HC). The oral glucose tolerance test was performed, and fast serum insulin (FSI) was detected using an enzyme-linked immunosorbent assay. The mRNA expression levels of glucose transporters (Sglt-1 and Glut-2) and proglucagon (Plg) in different intestinal segments (the duodenum, jejunum, ileum, and colon) were analyzed using quantitative real-time polymerase chain reaction. SGLT-1 protein and the morphology of epithelial cells in the duodenum and jejunum was localized by using immunofluorescence. Results At both doses, CGA ameliorated the HFD-induced body weight gain, maintained FSI, and increased postprandial 30-min glucagon-like peptide 1 secretion. High-dose CGA inhibited the HFD-induced elevation in Sglt-1 expression. Both CGA doses normalized the HFD-induced downregulation of Glut-2 and elevated the expression of Plg in all four intestinal segments. Conclusion An HFD can cause a glucose metabolism disorder in the rat intestine and affect body glucose homeostasis. CGA can modify intestinal glucose metabolism by regulating the expression of intestinal glucose transporters and Plg, thereby controlling the levels of blood glucose and insulin to maintain glucose homeostasis.