Dihydroartemisinin enhances radiotherapy efficiency in H22 cell tumor-bearing mice by regulating PI3K/AKT signaling pathway

AIM To study the effect of dihydroartemisinin （DHA） on the radiotherapy efficiency in hepatocellular carcinoma H22 cell tumor-bearing mice and the role of phosphatidylinositol 3-kinase （PI3K）/protein kinase B （AKT） signaling pathway in this process. METHODS A model of H22 cell tumor-bearing mice was established. The mice was divided into model group， single radiotherapy group， 5-fluorouracil （5-FU） group， and low-， medium- and high-dose DHA groups. The body weight and tumor volume in each group were measured every other day. At the end of administration， blood was collected from the tail of the mice and the animals were killed by neck removal immediately. The synergistic effect of DHA on radiotherapy was determined， and tumor growth inhibitory rate was calculated. The degree of lymphocyte transformation and natural killer （NK） cell activity were measured by MTT， the serum levels of interleukin-2 （IL-2） and IL-4 were measured by ELISA， and the protein levels of PI3K， AKT and p-AKT were determined by Western blot. RESULTS The H22 cell tumor-bearing mouse model was successfully constructed. Compared with model group， the TGT₃ （tumor growth time to reach 3 times of volume） of single radiotherapy group was remarkably increased （P<0.05）， while tumor weight， lymphocyte transformation degree， NK cell activity， IL-2 and IL-4 levels， PI3K protein level and AKT phosphorylation level were remarkably decreased （P<0.05）. Compared with single radiotherapy group， TGT₃， EF （enhancement factor）， tumor inhibitory rate， lymphocyte transformation degree， NK cell activity， IL-2 level and IL-4 level were increased with the increase in DHA dose （P<0.05）， and the PI3K protein level and AKT phosphorylation level were decreased （P<0.05）. CONCLUSION DHA may enhance the immunity of tumor-bearing mice by inhibiting the activity of PI3K/AKT signaling pathway， thereby enhancing the efficacy of radiotherapy.     

依普黄酮对骨质疏松症笼养蛋鸡OPG和RANKL表达的影响

选用200只24周龄健康海兰褐蛋鸡,随机分为4组:对照组(基础日粮中含钙3.55％)、低钙组(日粮合钙1.27％)、试验Ⅰ组(依普黄酮8 mg/kg,低钙日粮)和试验Ⅱ组(依普黄酮20 mg/kg,低钙日粮),观察依普黄酮对骨质疏松症笼养蛋鸡血清及骨骼骨保护素(Osteo protegerin,OPG)/核因子-相受体活化因子配体(Receptor activatorof NF-κB ligand,RANKL)表达的影响.结果显示:与低钙组相比,30 d时,试验Ⅰ组和Ⅱ组血清OPG分别显著升高33.12％和60.19％(P＜0.05)；60 d时,试验Ⅰ组和Ⅱ组血清OPG分别显著升高35.89％和61.59％ (P＜0.05)；30 d时,试验Ⅰ组和Ⅱ组血清RANKL分别极显著降低63.85％和70.87％(P＜0.01)；60 d时,试验Ⅰ组和Ⅱ组血清RANKL分别极显著降低69.98％和72.85％ (P＜0.01).与低钙组相比,试验Ⅰ组和Ⅱ组骨组织OPG平均光密度分别显著(P＜0.05)和极显著(P＜0.01)升高,试验Ⅰ组和Ⅱ组蛋鸡骨组织RANKL平均光密度极显著低于低钙组蛋鸡(P＜o.01).试验Ⅰ组和Ⅱ组OPG/RANKL值高于低钙组.结果表明,低钙日粮中添加依普黄酮对蛋鸡骨质疏松症可起到一定改善作用,这可能与OPG上调,RANKL下调,影响RANKL信号通路,使其骨量增加,骨结构改善密切相关.     

西葫芦银叶病发病叶片叶绿素代谢及其荧光特性

 研究了西葫芦银叶病发病叶片和叶柄叶绿素代谢特性和叶片叶绿素荧光参数的变化。与对照相比，发病叶片和叶柄叶绿素总量(Chl.a+b)，叶绿素a (Chl.a)，叶绿素b (Chl.b)含量均下降；轻度与重度发病叶片叶绿素a/b增加，中度发病叶片与对照差异不显著，而叶柄比对照降低。西葫芦银叶病对叶片Chl.b的影响比Chl.a大，而对叶柄Chl.a的影响比Chl.b大。发病叶片和叶柄叶绿素酶活性升高，从而使叶绿素降解加速，叶绿素合成中间产物Protoporphyrin IX (Proto IX)，Magnesium protoporphyrin IX (Mg-Proto IX)，Protochlorophyllide (Pchlide)含量降低，Uroporphyrinogen Ⅲ (Uro Ⅲ)含量增加，表明叶绿素合成在 Uro Ⅲ到 Proto Ⅸ受阻。发病叶片最大光化学量子产量(Fv/Fm)，光系统Ⅱ(PSⅡ)的潜在活性(F_v/F_o)，实际光化学效率(φPSⅡ)，光化学淬灭系数(q_P)降低，非光化学淬灭系数(NPQ)增加。试验结果表明，西葫芦银叶病破坏了叶绿素合成和降解的动态平衡，叶绿素合成受阻和叶绿素降解加速是导致叶片叶绿素含量降低的原因；发病叶片叶绿体PSⅡ活性受到抑制。     

水稻粒型调控基因功能研究进展

水稻是世界上的重要谷类粮食作物之一，其产量和品质一直都是育种学家关注的重点，关系到全球粮食安全和人类健康。水稻粒型主要包括粒长、粒宽、粒厚等，是受多基因控制的重要数量性状，不仅直接影响水稻产量，还与水稻品质密切相关。深入了解水稻粒型的形成与调控机理将有助于进一步提升水稻单株产量、改善稻米品质。分子生物学的发展和基因组学的研究为探究水稻内部调控机制带来了新的变革。大量水稻粒型的数量性状遗传位点（Quantitative trait locus，QTL）成功被鉴定与解析，并验证了与之有关的基因功能。目前，已有几条调控粒型的通路得到鉴定，如泛素 - 蛋白酶体降解途径、G 蛋白信号途径、丝裂原活化蛋白激酶途径、转录因子调控途径、植物激素途径以及表观遗传途径等。然而，粒型调控网络极其复杂，多数基因上下游的调控组件作用机制尚不清楚，甚至影响粒型的各条通路间均存在一定的交叉互作。本文综述了影响水稻粒型的不同信号通路相关基因研究进展及关键粒型基因间的互作关系，总结了近年来粒型基因在育种上的应用情况，并提出结合多组学解析水稻粒型的调控机理研究，以期更好地服务于分子设计育种，为开发新的高产优质稻育种提供支撑。     

鹅羽绒发生发育的分子调控机理研究进展

简要概述了鹅羽绒毛囊形态发生和生长周期的循环过程,对Wnt/β-catenin信号传导途径、Shh传导途径、部分相关基因功能及其调控羽绒发生发育的分子机理进行了综述,并提出了目前研究中仍存在的问题。     

植物香豆素生物合成途径及关键酶基因研究进展

香豆素是来源于苯丙烷代谢途径中重要的次级代谢产物,具有多种生物活性,对植物的生长发育及应答逆境胁迫有重要作用。本研究对香豆素生物合成途径以及所涉及的关键酶基因研究进展进行综述,分析了葡萄糖基转移酶基因家族的系统进化,并对香豆素目前研究的问题进行总结以及今后的研究方向进行展望,以期为香豆素生物合成及其后续研究提供借鉴。     

非洲猪瘟病毒感染后猪外周血淋巴细胞Toll样受体信号通路的lncRNA-mRNA分析

【目的】丰富非洲猪瘟病毒（African swine fever virus,ASFV）感染后猪外周血淋巴细胞长链非编码RNA（long non-coding RNA,lncRNA）表达谱,并进一步挖掘影响Toll样受体信号通路的调控网络。【方法】试验动物感染ASFV,于第7天采集外周血并分离得到外周血淋巴细胞,运用Illumina高通量组学测序对外周血淋巴细胞中lncRNA进行测序,原始数据经处理后筛选获得差异表达的lncRNA,并进行靶基因预测,利用生物信息学方法对靶基因进行GO功能和KEGG信号通路富集分析,初步绘制与Toll样受体信号通路相关的lncRNA-mRNA调控网络,并对lncRNA-ENSSSCG00000041959在内的4个lncRNAs进行实时荧光定量RT-PCR验证。【结果】共筛选到73个差异表达的lncRNAs,其中上调表达lncRNAs 38个,下调表达lncRNAs 35个。GO功能分析结果显示,靶基因显著富集在调节免疫系统过程、防御反应、生物刺激、病毒反应和先天性免疫;KEGG信号通路富集分析显示,大部分靶基因与细胞循环、疾病及免疫应答有关,其中免疫相关信号通路有Toll样受体信号通路、TNF信号通路、产生IgA的肠道免疫网络等。进一步挖掘出lncRNA-ENSSSCG00000041959-RIPK1和lncRNA-ENSSSCG00000041959-IRAK1可能是影响Toll样受体信号通路的重要调控网络,实时荧光定量RT-PCR与测序结果一致。【结论】本研究初步鉴定出lncRNA-ENSSSCG00000041959-RIPK1和lncRNA-ENSSSCG00000041959-IRAK1可能是影响Toll样受体信号通路的lncRNA-mRNA调控网络,为进一步探索lncRNA调控ASFV感染机体免疫反应奠定了理论基础。     

GPX4失活通过JNK通路缓解LPS诱导巨噬细胞炎症反应

【目的】 研究硒蛋白谷胱甘肽过氧化物酶4（glutathione peroxidases 4,GPX4）失活如何参与调控脂多糖（lipopolysaccharide,LPS）诱导的RAW264.7巨噬细胞炎症反应及其潜在的分子机制。【方法】 体外培养RAW264.7巨噬细胞,以DMSO为对照,使用0.1~5.0 μmol/L GPX4抑制剂FIN56处理,通过CCK-8法检测细胞活力和Western blotting检测GPX4蛋白表达水平,确定抑制剂最适浓度。将RAW264.7巨噬细胞分为4组：对照组,添加DMSO培养24 h;FIN56（GPX4抑制剂）组,添加0.5 μmol/L FIN56培养24 h;DMSO-LPS组,DMSO培养24 h后使用LPS （100 ng/mL）刺激3 h;FIN56-LPS组,FIN56培养24 h后使用LPS刺激3 h。各组细胞经培养后,利用荧光探针2',7'-二氯二氢荧光素二乙酸酯（2',7'-dichlorodi-hydrofluorescein diacetate,H₂DCFDA）检测细胞内活性氧（reactive oxygen species,ROS）水平,使用试剂盒法检测细胞内丙二醛（malondialdehyde,MDA）水平,分别使用ELISA和荧光定量PCR检测促炎细胞因子白细胞介素1β（interleukin-1β,IL-1β）、白细胞介素6（interleukin-6,IL-6）、肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）的分泌水平和基因表达量,使用Western blotting法检测Toll样受体4（toll like receptor 4,TLR4）信号通路相关蛋白表达水平。【结果】 与DMSO处理相比,0.5 μmol/L FIN56处理巨噬细胞24 h对细胞活性无显著影响（P>0.05）,且显著降低GPX4蛋白表达水平（P<0.05）,故选用0.5 μmol/L FIN56用于后续实验。与对照组相比,FIN56和LPS均显著增加了ROS积累（P<0.05）,而与DMSO-LPS组相比,FIN56-LPS组ROS水平显著升高（P<0.05）。与对照组相比,LPS可显著增加小鼠巨噬细胞IL-1β、IL-6和TNF-α的mRNA表达量和IL-6含量,以及c-Jun氨基末端蛋白激酶（c-Jun N-terminal protein kinase,JNK）和c-Jun磷酸化水平（P<0.05）,而FIN56可显著下调LPS诱导的IL-6的mRNA表达量和含量及JNK和c-Jun磷酸化水平（P<0.05）,但对p38蛋白（p38 MAPK,p38）、细胞外调节蛋白激酶（phosphorylate extracellular regulated protein kinases1/2,Erk1/2）蛋白表达水平无显著影响（P>0.05）。【结论】 GPX4失活可有效阻断JNK和c-Jun磷酸化,从而特异性抑制LPS诱导的巨噬细胞的炎症反应。该结果可为以GPX4为靶点研发抗炎治疗策略提供理论依据。     

Screening of extracts of Japanese woods for melanin biosynthesis inhibition

The effects of 120 methanol extracts prepared from bark and heartwood of 69 types of Japanese wood on the melanin production of B16 melanoma cells were examined. The melanin content of B16 melanoma cells was determined spectrophotometrically at 405nm. The extracts were also examined for their effects on cell viability. We found that the methanol extracts of Fagus crenata (buna, wood, 100μg/ml), Sapium sebiferum (Nankinhaze, wood, bark, 10μg/ml), and Zelkova serrata (keyaki, wood, 10μg/ml) greatly inhibited the melanin production of B16 melanoma cells without significant cytotoxicity. However, these extracts did not inhibit tyrosinase activity at the concentration of 100μg/ml. These findings indicate that the depigmenting mechanism of these extracts involves the suppression of some pigmenting signals in stimulating melanogenesis rather than the inhibition of tyrosinase activity. Part of this study was presented at the 53rd Annual Meeting of the Japan Wood Research Society, Fukuoka, Japan, March 2003     

The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 14

The genetic organization of the gene involved in the capsular polysaccharide (CPS) biosynthesis of Actinobacillus pleuropneumoniae serotype 14 has been determined. The DNA region for the CPS biosynthesis of serotype 14 (cps14) comprised 9 open reading frames, designated as cps14AB₁B₂B₃CDEFG genes, encoding Cps14A to Cps14G protein, respectively. Cps14A was similar to CpsA of A. pleuropneumoniae serotypes 1, 4 and 12; the Cps14B₁ and Cps14B₂ were similar to CpsB of A. pleuropneumoniae serotypes 1, 4 and 12, suggesting that CPS structure of A. pleuropneumoniae serotype 14 would belong to Group I including A. pleuropneumoniae serotypes 1, 4, 12 and 15. Surprisingly, the overall nucleotide sequence, deduced amino acid sequence, and the genetic organization of the cps14 were nearly identical to those of Actinobacillus suis. This study will provide the molecular basic knowledge for development of diagnostics and vaccine of A. pleuropneumoniae serotype 14.