Toll样受体5和鞭毛蛋白的相互作用影响宿主区分病原菌和益生菌（英文稿）

【目的】大量的证据表明机体正常的免疫活动在很大程度上依赖于免疫系统和肠道菌群的相互作用,具体表现为免疫系统对病原菌进行免疫清除而对益生菌耐受。其中,免疫系统的Toll样受体(Toll-like receptors,TLRs)和来自肠道菌群的微生物相关的分子模型(Microorganism associated molecular patterns,MAMPs)被认为在宿主免疫系统对病原菌和益生菌的区分中发挥了重要作用,因为TLRs对MAMPs的识别能够激活先天性和获得性免疫反应。在TLRs对MAMPs的识别中,只有TLR5对细菌鞭毛蛋白的识别是基于蛋白-蛋白的相互作用,比较容易对其结合方式进行研究。因此,我们研究的主要目的就是要确定TLR5与鞭毛蛋白的相互作用是如何影响宿主区分病原菌和益生菌的。【方法】构建了多种肠道细菌(包括益生菌和病原菌)鞭毛蛋白的系统发育树,并比对了鞭毛蛋白的TLR5识别序列。【结果】发现病原菌和益生菌的鞭毛蛋白序列有所不同,尤其是TLR5结合并识别的鞭毛蛋白位点。【结论】病原菌和益生菌不同的鞭毛蛋白识别区域可能是鞭毛细菌适应TLR5识别下生存的结果,据此宿主能够对病原菌和益生菌进行区分。此外,相关研究表明TLRs在肠上皮细胞的分布具有基底侧和顶端的两极性,能够分别引发对病原菌的免疫反应和对益生菌的免疫耐受,从而抵御病原菌的入侵感染、与益生菌和平共处。鞭毛蛋白和TLR5蛋白的相互作用反映了肠道菌群和免疫系统在分子层面的相互作用和共同进化,是宿主区分病原菌和益生菌的分子机制之一。     

Di-methylation of CD147-K234 Promotes the Progression of NSCLC by Enhancing Lactate Export

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Dynamic Modeling of a Man–Land System in Response to Environmental Catastrophe

A compatible relationship between “man” and “land” is the essence of regional sustainable development. In this article VENSIM PLE is used to set up a system dynamics (SD) model of the regional man–land system of Xiangfan, Hubei Province, China. The model is used to simulate dynamic behaviors of society and economy in the face of environmental catastrophe, in order to explore dynamic response among subsystems in man–land systems, and to research mechanisms of regional sustainable development. The model is also used to forecast impacts from the south-to-north water transfer project in China on the environment, society, and economy within a time span of 50 years. The model is further used to verify the effects of suggested regulatory policies. The simulation results show counterintuitive outcomes. The most serious impact on Xiangfan caused by the water transfer project would be on economic growth, not on environment quality. However, if a series of regulatory policies were carried out in advance of the water project's construction, the trends of concern could be effectively eased. SD provides tools for precisely understanding complex man–land systems, which always seem counterintuitive. However, there still exist limitations and disadvantages in the model that must be overcome. It is believed that the next logical step in deriving better dynamic models of man–land systems is to integrate SD with other advanced algorithms or technologies.     

Semi-Synthesis of Flavonoid Glycosides and Their Anti-Inflammatory and Antitumor Activities towards Triple Negative Breast Cancer

Background : Flavonoid glycosides are known to possess diverse bioactivities including antitumor and anti-inflammatory properties. Hesperetin is abundant in nature and can be used to synthesize bioactive flavonoids. This has the advantages of low cost, short synthetic steps, simple operation, and good yields. Objective : In this study, we aimed to synthesize bioactive flavonoids and flavonoid glycosides from hesperetin and evaluate the antitumor and anti-inflammatory activities of these compounds. Methods : A series of flavonoids and their derivatives were synthesized by methoxylation, oxidative dehydrogenation, benzylation, debenzylation, and deacetylation as well as using a modified peroxyacetone method and a glycoside condensation reaction. Their anti-inflammatory activities were evaluated for their inhibitory effects on nitric oxide (NO), tumor necrosis factor (TNF-α), and interleukin-6 (IL-6) production in LPS-induced RAW264.7 mouse macrophages. Their structures were characterized by HRMS, ¹H-NMR, and ¹³C-NMR, and their cytotoxicity on the human triple-negative breast cancer cell (TNBC) line, SUM 149, was tested by using the MST assay. Results : Most of the compounds markedly reduced NO production in LPS-stimulated murine macrophages at the tested concentrations in a dose-dependent manner. Among these, compounds 1 , 7 , 9 , and 17 showed significant anti-inflammatory activities against NO production in LPS-induced RAW264.7 mouse macrophages. In addition, they could also reduce the release of TNF-α and IL-6 in a concentration-dependent manner. Most of the tested compounds showed remarkable anti-human TNBC activities. Compounds 1b – 1m , 1 , and 3 showed a certain degree of growth inhibition effect on the human TNBC cell lines and their IC₅₀ values were all below 16.61 μM. In addition, compound 1l was the most cytotoxic with IC₅₀ values of 1.38±0.31 μM, while the other compounds were inactive with inhibition rates <50 % at the highest concentration tested (20 μM). Conclusions : A novel series of flavonoids were synthesized from the natural flavonoid, hesperetin, including 17 new compounds. Screening tests indicated that most of these compounds reduced NO production in LPS-stimulated murine macrophages at concentrations of 15 to 60 μM, and the inhibition generally increased in a dose-dependent manner. Some compounds showed different degrees of cytotoxicity on the human TBNC cell lines, SUM 149.     

Plant regeneration from embryogenic cell suspensions and protoplasts of dessert banana cv. ‘Da Jiao’ (<Emphasis Type="Italic">Musa paradisiacal</Emphasis> ABB Linn.) via somatic embryogenesis

The ‘Da Jiao’ cultivar of banana (Musa paradisiacal ABB Linn.) is an ideal germplasm to produce new banana varieties resistant to Fusarium oxysporum f. sp. cubense (FOC) race 4, for this cultivar is not only a popular dessert banana in south China, but also bears high resistance to FOC race 4. In this study, we established a homogeneous embryogenic cell suspension (ECS) of ‘Da Jiao’ and obtained regenerated plants from ECS-derived protoplasts via somatic embryogenesis. The ECS was initiated from yellow friable callus induced from immature male inflorescence on M1 medium. A pre-culture was used to select ECS in M2 medium without 2,4-dichlorophenoxyacetic acid for 10 d. Addition of 1.0 mg L⁻¹ abscisic acid to M3 medium could enhance the frequency of somatic embryogenesis by about 2.6-fold. Protoplasts, with a yield range of 5–6 × 10⁶ per milliliter, were isolated from the ECS. About 0.35% of the protoplasts formed microcallus, which contained about 100 cells, after 1 mo of feeder layer culture with ECS of Musa acuminate cv. Mas (AA) as nurse cells. Healthy plantlets (0.14%) were regenerated from the microcallus through somatic embryogenesis.