急性髓系白血病mRNA与非编码RNA差异表达谱及CeRNA调控网络分析

利用GEO数据库(gene expression omnibus database)通过生物信息学分析方法探讨急性髓系白血病(acute myelogenous leukemia,AML)的发病机制。检索GEO数据库中AML相关芯片数据集GSE142698、GSE142699和GSE96535。利用GEO2R分析得到差异mRNAs、miRNAs以及差异lncRNAs。利用在线生物信息学分析工具DAVID对差异mRNAs进行GO富集分析和KEGG通路分析。利用miRWalk数据库预测AML相关miRNAs的靶向mRNAs,利用Spongescan数据库预测AML相关miRNAs的靶向lncRNAs,构建lncRNA-miRNA-mRNA竞争性内源RNA （competing endogenous RNA,ceRNA）调控网络。共筛选出29个显著差异mRNAs、70个显著差异miRNAs和20 005个显著差异lncRNAs。GO富集分析和KEGG通路分析显示,差异表达基因主要涉及蛋白磷酸化、细胞分裂、细胞增殖的负调控、基因表达的正向调节、周期蛋白依赖的丝氨酸/苏氨酸激酶活性的调节等生物过程以及细胞周期、细胞衰老、癌症通路、PI3K-Akt通路等信号通路。将miRWalk数据库预测的靶向mRNAs与差异mRNAs取交集,Spongescan数据库预测的靶向lncRNAs与差异lncRNAs取交集,分别确定了25个mRNAs、6个lncRNAs参与AML相关ceRNA调控网络的构建。结果表明,lncRNAs可能作为关键的ceRNA,通过调控miRNA和相关靶基因参与AML的发生与发展,研究结果为AML诊断和治疗的分子生物学研究提供了新的依据。     

Engeletin alleviates cerebral ischemia reperfusion-induced neuroinflammation via the HMGB1/TLR4/NF-κB network

High-mobility group box1 (HMGB1) induces inflammatory injury, and emerging reports suggest that it is critical for brain ischemia reperfusion. Engeletin, a natural Smilax glabra rhizomilax derivative, is reported to possess anti-inflammatory activity. Herein, we examined the mechanism of engeletin-mediated neuroprotection in rats having transient middle cerebral artery occlusion (tMCAO) against cerebral ischemia reperfusion injury. Male SD rats were induced using a 1.5 h tMCAO, following by reperfusion for 22.5 h. Engeletin (15, 30 or 60 mg/kg) was intravenously administered immediately following 0.5 h of ischemia. Based on our results, engeletin, in a dose-dependent fashion, reduced neurological deficits, infarct size, histopathological alterations, brain edema and inflammatory factors, namely, circulating IL-1β, TNF-α, IL-6 and IFN-γ. Furthermore, engeletin treatment markedly reduced neuronal apoptosis, which, in turn, elevated Bcl-2 protein levels, while suppressing Bax and Cleaved Caspase-3 protein levels. Meanwhile, engeletin significantly reduces overall expressions of HMGB1, TLR4, and NF-κB and attenuated nuclear transfer of nuclear factor kappa B (NF-κB) p65 in ischemic cortical tissue. In conclusion, engeletin strongly prevents focal cerebral ischemia via suppression of the HMGB1/TLR4/NF-κB inflammatory network.     

Differences between migrasome,a ‘new organelle’, and exosome

The migrasome is a new organelle discovered by Professor Yu Li in 2015. When cells migrate, the membranous organelles that appear at the end of the retraction fibres are migrasomes. With the migration of cells, the retraction fibres which connect migrasomes and cells finally break. The migrasomes detach from the cell and are released into the extracellular space or directly absorbed by the recipient cell. The cytoplasmic contents are first transported to the migrasome and then released from the cell through the migrasome. This release mechanism, which depends on cell migration, is named ‘migracytosis’. The main components of the migrasome are extracellular vesicles after they leave the cell, which are easy to remind people of the current hot topic of exosomes. Exosomes are extracellular vesicles wrapped by the lipid bimolecular layer. With extensive research, exosomes have solved many disease problems. This review summarizes the differences between migrasomes and exosomes in size, composition, property and function, extraction method and regulation mechanism for generation and release. At the same time, it also prospects for the current hotspot of migrasomes, hoping to provide literature support for further research on the generation and release mechanism of migrasomes and their clinical application in the future.     

Effect of Flowering Stages on the Content of Active Ingredients and Antioxidant Capability of Bletilla striata Flowers

Bletilla striata (Thunb.) Reichb.f. is a perennial herb with abundant active ingredients. Previous research mainly focused on its tubers, however, the study on flowers, especially the variation of active ingredient contents at different flowering stages, was rarely seen. This study analyzed the total phenols, flavonoids, polysaccharides, anthocyanins, and cyanidin-3-O-glucoside content of B. striata flowers which were in cultivated in Herb Garden of Zhejiang A&F University and collected in May, 2019, in order to investigate the changes in active ingredients and antioxidant capacity among different flowering stages (bud, initial, and full bloom). Changes in radical scavenging capability of DPPH (1,1-Diphenyl-2-picrylhydrazyl radical), ABTS (2,2′-azinobis(3-ethylbenzthiazoline-6-sulphonate)), and hydroxy were analyzed. Significant differences in active ingredient content of flowers were detected among different flowering stages. The total phenolic content increased continuously during the entire flowering stage. The contents of total flavonoid, total polysaccharide, and cyanidin-3-O-glucoside reached peaks at the initial blooming stage and then fell as the flowering process continued. The antioxidant activity in initial stage was the highest than in any other flowering stages. Therefore, we conclude that the initial blooming stage is the best harvesting stage of B. striata flowers. This study provides a robust basis for the harvest and utilization of B. striata flowers in food, medical, and cosmetic industries.     

The legacy effect of biochar application on soil nitrous oxide emissions

Existing studies suggest that biochar application can reduce soil nitrous oxide (N₂O) emissions, mainly based on short-term results. However, it remains unclear what the effects (i.e., legacy effects) and underlying mechanisms are on N₂O emissions after many years of a single application of biochar. Here, we collected intact soil columns from plots without and with biochar application in a subtropical tea plantation 7 years ago for an incubation experiment. We used the N₂O isotopocule analysis combined with ammonia oxidizer-specific inhibitors and molecular biology approaches to investigate how the legacy effect of biochar affected soil N₂O emissions. Results showed that the soil in the presence of biochar had lower N₂O emissions than the control albeit statistically insignificant. The legacy effect of biochar in decreasing N₂O emissions may be attributed to the reduced effectiveness of the soil substrate, nitrification and denitrification activities, and the promotion of the further reduction of N₂O. The legacy effect of biochar reduced the relative contribution of nitrifier denitrification/bacterial denitrification, nitrification-related N₂O production, and the relative abundance of several microorganisms involved in the nitrogen cycle. Our global meta-analysis also showed that the reduction of N₂O by biochar increased with increasing application rate but diminished and possibly even reversed with increasing experimental time. In conclusion, our findings suggest that the abatement capacity of biochar on soil N₂O emissions may weaken over time after biochar application, but this remains under further investigation.     

Efficient polymer-mediated delivery system for thiocyclam: Nanometerization remarkably improves the bioactivity toward green peach aphids

The unscientific application of synthetic pesticides has brought various negative effects on the environment, hindering the sustainable development of agriculture. Nanoparticles can be applied as carriers to improve pesticide delivery, showing great potential in the development of pesticide formulation in recent years. Herein, a star polymer (SPc) was constructed as an efficient pesticide nanocarrier/adjuvant that could spontaneously assemble with thiocyclam or monosultap into a complex, through hydrophobic association and hydrogen bonding, respectively, with the pesticide-loading contents of 42.54% and 19.3%. This complexation reduced the particle sizes of thiocyclam from 543.54 to 52.74 nm for pure thiocyclam, and 3 814.16 to 1 185.89 nm for commercial preparation (cp) of thiocyclam. Interestingly, the introduction of SPc decreased the contact angles of both pure and cp thiocyclam on plant leaves, and increased the plant uptake of cp thiocyclam to 2.4–1.9 times of that without SPc. Meanwhile, the SPc could promote the bioactivity of pure/cp thiocyclam against green peach aphids through leaf dipping method and root application. For leaf dipping method, the 50% lethal concentration decreased from 0.532 to 0.221 g/L after the complexation of pure thiocyclam with SPc, and that decreased from 0.390 to 0.251 g/L for cp thiocyclam. SPc seems a promising adjuvant for nanometerization of both pure and cp insecticides, which is beneficial for improving the delivery efficiency and utilization rate of pesticides.     

pH对灵芝液态发酵代谢物及抗氧化活性的影响

已有研究报道灵芝栽培生长的最适pH在中性偏酸环境,在碱性范围的生长及代谢情况鲜见报道。本研究主要探究广泛pH对灵芝液态发酵代谢物及其抗氧化活性的影响。采用摇瓶液态培养后分析代谢物中灵芝三萜、胞内外多糖、菌丝体蛋白及抗氧化活性等指标,系统比较灵芝菌丝体在pH值2-11的生长和代谢情况。研究结果表明,灵芝菌丝体生长、合成灵芝三萜、胞内多糖、30E胞外多糖、菌丝体蛋白和菌丝体水解氨基酸的最适pH值分别为10、3、2、7、2和2。对应结果分别为17.13 g/L、33.86 mg/g、72.73 mg/g、7.86 g/L、71.42 mg/g和107.10 mg/g。比对照分别提高28.5%、77.3%、22.4%、96.5%、97.1%和70.8%。胞内多糖组分1和组分2最高分子量均在初始pH 4,分别为1.016×10⁸ g/mol和9.280×10⁴ g/mol,胞外多糖组分1最高分子量在初始pH 10,为4.946×10⁶ g/mol;对菌丝体的总抗氧化能力、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2- picrylhydrazyl,DPPH)自由基清除能力、羟自由基清除能力分析结果表明最佳的初始pH分别为3、7、9。本研究为液态发酵方式下灵芝生长及其代谢物定向调控发酵的工艺优化提供参考依据,同时发现灵芝菌丝体中优质蛋白及抗氧化活性可在功能性食品和化妆品领域推广应用。     

Mutational meltdown or controlled chain reaction: The dynamics of rapid plastome evolution in the hyperdiversity of Poaceae

The study of genomic structural evolution associated with accelerated evolutionary rates that result in avoidance of meltdown and increase biodiversity is becoming ever more possible as the number of available plastomes increases. To more comprehensively analyze rate heterogeneity among monocots and within Poaceae, we sequenced plastomes from four Poaceae species, combined them with publicly available data from ~200 plastomes, and conducted comparative analyses to quantify the pattern of rate heterogeneity between different lineages, functional groups, and periods of evolutionary time. We compared structural differences across the Poaceae to quantify how changes in plastome size correspond to different genomic subunits and the evolution of IR–SC junction boundaries. The substitution rates among ancestral Poaceae were inferred to be exceptionally rapid compared to other monocots but slowed after divergence into extant lineages, which could not be sufficiently explained by positive selection. As such, rapid rates in the ancestral lineage leading to Poaceae might be more closely linked to large-scale structural changes like the loss of ycf1 and ycf2. The total increase in plastome size across Poaceae was positively correlated with the total length of intergenic spacers, tandem repeats, and dispersed repeats as well as large single copy, and inverted repeats (IRs). The continuous evolution of IR–SC junction boundaries was asynchronous with sizes of total genome and subunits across Poaceae. Future work is needed to better understand what factors in ancestral Poaceae evolved to harness such rapid rates of plastome evolution, avoid a mutational meltdown, and escape the stagnation of strong purifying selection as well as if these factors could be utilized to synthetically control rates.     

梅花鹿甲烷能代谢规律的研究

本文应用ＫＢ－１型呼吸测热装置,结合消化、代谢试验,对梅花鹿（Ｃｅｒｖｕｓｎｉｐｐｏｎ）甲烷能代谢规律进行了研究。结果表明,梅花鹿甲烷能的产生量随其采食量的增加而增加;也随着果食后时间的推移而减少,而且减少的幅度又随采食量的增加而下降;甲烷能的产生量分别占总能食入量、消化能食入量和体增热的６．６１％、８．８３％和１０．８８％;甲烷能的产生量随着日粮蛋白质水平的提高而降低,日粮蛋白质水平每提高１个百分点,甲烷能产生量就降低５８．５８ｋＪ／ｄ;分别以总能食入量（ＧＥＩ）和干物质食入量（ＤＭＩ）为自变量所建立的甲烷能（ＣＨ４Ｅ）估计分别为：ＣＨ４Ｅ（ｋＪ／ｄ）＝０．０７ＣＥＪ（ｋＪ／ｄ）－１０１．０４（ｎ＝１２,ｒ＝０．９４４,Ｐ＜０．０１）ＣＨ４Ｅ（ｋＪ／ｄ）＝９８．７８＋１．０５ＤＭＩ（ｇ／ｄ）（ｎ＝１２,ｒ＝０．９４２,Ｐ＜０．０１）