竹叶椒抑制血小板活化因子（PAF）的活性成分

自芸香科花椒属植物竹叶椒（Zanthoxglum planispinum Sieb.et Zucc）根和茎的石油醚及二氯甲烷提取物中分离得到5个化合物（I～V）,经物理常数测定,光谱（UV,IR,HNMR,MS）分析分别鉴定,Ⅰ为β-香木脂醇,Ⅱ为β-谷甾醇,Ⅲ为L-细辛脂素,Ⅳ为L-竹叶椒脂素,V为花椒明碱。其中Ⅲ,IV,V具有抑制PAF聚集的活性,以Ⅳ活性最强,Ⅲ次之,V较弱。花椒明碱首次从该植物中分离得到。     

基于叶干质量比的杉木比叶面积估算模型的构建

随着叶片功能性状研究的不断深入, 通过简单易测量的叶片指标, 同时探究植物生活史权衡对策和估算林分生产力的研究需求日益增长, 例如叶干质量比(LDMC)和比叶面积(SLA)的相互转换。杉木(Cunninghamia lanceolata)是亚热带重要的常绿针叶树种, 基于LDMC对杉木SLA进行估算, 能够为核算SLA提供途径, 为机理解释和生产估算构建连接途径, 为小区域到大尺度、精算到估算搭建桥梁。该研究在湖南会同和河南信阳两个杉木生长区, 对处于不同小生境(坡向、坡位和冠层深度)以及不同生活史(林龄和叶龄)的叶片进行抽样和采集, 通过测得不同叶龄的单叶LDMC和SLA, 初步探究在不同因子下两个性状值的分布差异, 进一步基于LDMC构建SLA估算模型并讨论以叶龄为差分因子对模型的影响。结果表明: 1)杉木SLA平均值为(103.15 ± 69.54) cm ²·g ^-1, LDMC为0.39 ± 0.11; 2)杉木LDMC和SLA可用非线性模型进行估算, 模型符合估算要求; 3)其中一年生叶的拟合效果最好, 老叶(大于二年生叶)的拟合优度较低, 老叶较低的SLA (52.28-75.74 cm ²·g ^-1)可能暗示LDMC的变化保持相对独立性。该研究基于杉木LDMC的SLA估算模型可信且有效, 且不同叶龄对LDMC和SLA的影响可能预示着杉木叶片的响应敏感性和生活史权衡策略。     

Functional and molecular mechanism of intracellular pH regulation in human inducible pluripotent stem cells

AIM To establish a functional and molecular model of the intracellular pH(pH_i) regulatory mechanism in human induced pluripotent stem cells(hiPSCs).METHODS hiP SCs(HPS0077) were kindly provided by Dr. Dai from the Tri-Service General Hospital(IRB No. B-106-09). Changes in the pH_i were detected either by microspectrofluorimetry or by a multimode reader with a pH-sensitive fluorescent probe, BCECF, and the fluorescent ratio was calibrated by the high K~+/nigericin method. NH_4Cl and Na-acetate prepulse techniques were used to induce rapid intracellular acidosis and alkalization, respectively. The buffering power(β) was calculated from the ΔpH_i induced by perfusing different concentrations of(NH_4)_2SO_4. Western blot techniques and immunocytochemistry staining were used to detect the protein expression of pH_i regulators and pluripotency markers.RESULTS In this study, our results indicated that(1) the steadystate pH_i value was found to be 7.5 ± 0.01(n = 20) and 7.68 ± 0.01(n =20) in HEPES and 5% CO_2/HCO_3~- buffered systems, respectively, which were much greater than that in normal adult cells(7.2);(2) in a CO_2/HCO_3~--buffered system, the values of total intracellular buffering power(β) can be described by the following equation: β_(tot) = 107.79(pH_i)~2-1522.2(pH_i) + 5396.9(correlation coefficient R~2 = 0.85), in the estimated pH_i range of 7.1- 8.0;(3) the Na~+/H~+ exchanger(NHE) and the Na~+/HCO_3~- cotransporter(NBC) were found to be functionally activated for acid extrusion for pHi values less than 7.5 and 7.68, respectively;(4) V-ATPase and some other unknown Na~+-independent acid extruder(s) could only be functionally detected for pHi values less than 7.1;(5) the Cl~-/OH~- exchanger(CHE) and the Cl~- /HCO_3 anion exchanger(AE) were found to be responsible for the weakening of intracellular proton loading;(6) besides the CHE and the AE, a Cl~--independent acid loading mechanism was functionally identified; and(7) in hiPSCs, a strong positive correlation was observed between the loss of pluripotency and the weakening of the intracellular acid extrusion mechanism, which included a decrease in the steady-state pH i value and diminished the functional activity and protein expression of the NHE and the NBC.CONCLUSION For the first time, we established a functional and molecular model of a pHi regulatory mechanism and demonstrated its strong positive correlation with hiPSC pluripotency.     

Plasma lipidomics identifies novel biomarkers in patients with hepatitis B virus-related acute-on-chronic liver failure

Introduction

Acute-on-chronic liver failure (ACLF) is a fatal syndrome that presents with acute deterioration of liver function in chronic hepatitis B virus (HBV) patients. However, reliable diagnostic and prognostic biomarkers are scarce.

Objectives

The aim of this study to identify lipid species associated with HBV infection as well as novel lipid biomarkers for HBV-ACLF.

Methods

High performance liquid chromatography–tandem mass spectrometry was used for targeted lipidomic analyses of 147 lipid species. Fasting-state plasma samples from 74 HBV-ACLF patients, 86 HBV-non-ACLF patients [30 HBV-immune tolerant (HBV-IT) and 56 chronic hepatitis B] and 20 healthy controls. Univariate and multivariate analyses examined changes in lipid species among patient groups.

Results

The HBV-ACLF and HBV-non-ACLF groups had distinctly different lipid profiles, while the HC and HBV-IT groups had similar lipid profiles. Further, lysophosphatidylcholine (LPC) 22:6, cholesterol ester (CE) 22:6, CE 20:4, CE 18:2 and CE 18:1 could be used as potential biomarkers for the early prediction of ACLF. Meanwhile, univariate and multivariate analyses identified CE 20:4, LPC 16:0, LPC 18:0, phosphatidylcholine (PC) 40:6 and PC 32:0 as putative diagnostic biomarkers of HBV-ACLF. Moreover, LPC 16:0 and LPC 18:0 were significantly associated with model for end stage liver disease (MELD) scores, and the two lipid species combined with MELD score had significant capability to predict the 6-month mortality.

Conclusions

Our study revealed that lipid metabolism disorders were significantly associated with the severity of liver inflammatory injury rather than HBV infection in patients with chronic HBV infection, and specific lipid species could be used as potentially biomarkers for diagnosis and prognosis in HBV-ACLF.

     

Effects of Explants,Medium Formulations and Light on Callus Induction and Secondary Metabolites Accumulated in the Calli of Polygonum cuspidatum (Polygonaceae)

Callus initiation of a Chinese traditional medical plant , Polygonum cuspidatum Sieb. et Zucc (Polygonaceae) was studied, with a focus on the factors that could influence the callus induction ability and secondary metabolites accumulation. In comparison with the parent explants, the levels of total phenolics and flavones were 2 to 3-fold higher and the levels of anthraquinones (AQ_s) were lower in all calli induced. Different explants exhibited great variability in callus induction rate and secondarymetabolite accumulation. Among the three explants tested, leaf explants were with the best capacity in callus induction, while root explants accumulated the highest levels in secondary metabolites. Two media of six tested, MS and N6 respectively plus 0.5 mg/L 2, 4-dichlorophenoxy acetic acid and 1.0 mg/L 6-benzylaminopurine, showed the best performances in both callus growth and secondary metabolite accumulation. Illumination shower a remarkable effects on both callus induction and secondary metabolite accumulation, but no regular pattern was observed.     

PAT家族蛋白在细胞内脂滴代谢过程中的作用

哺乳动物细胞内的甘油三酯是以脂滴的形式贮存的,现在有很多证据表明,脂滴参与多种代谢过程,因而被看作胞内有功能的细胞器。脂滴含有甘油三酯构成的脂质核心,脂核表面覆盖有单层磷脂,在单层磷脂内镶嵌着在结构上具有相关性的PAT家族蛋白,包括perilipin、ADRP、TIP47和S3—12。本文就这些蛋白在甘油三酯水解和脂滴合成中的调节作用加以综述。     

Molecular phylogeny of Osmanthus(Oleaceae)based on non-coding chloroplast and nuclear ribosomal internal transcribed spacer regions

The phylogenetic relationships of Osmanthus Lour.were investigated using the nuclear ribosomal internal transcribed spacer(ITS)regions and non-coding chloroplast regions(psbA-trnH,trnL-F).The two datasets support the conclusion that Osmanthus is polyphyletic.with some species of the subtribe Oleinae nested within Osmanthus.Osmanthus didymopetalus P S.Green is nested within the clade formed by species of section Osmanthus in two trees.Osmanthus attenuatus P.S.Green.O.Funnanensis P.S.Green,and O gracilinervis R.L.Lu of traditional section Osmanthus are clearly divergent from other accessions,and do not form a monophyletic group with other Osmanthus accessions.Osmanthus marginatus Hemsl.is embedded in the clade formed by species of section Osmanthus in the ITS tree.In cpDNA trees all species of section Osmanthus are placed in the large clade and all species of section Leiolea formed a group.The taxonomic incongruence among trees for ITS and cpDNA indicate hybridization.as introgression may have occurred among some species of sections Osmanthus and Leiolea.Phylogeny of Osmanthus is discussed in light of molecular and morphological data,and a revised infrageneric classification with three sections(Leiolea,Siphosmanthu,and Osmanthus)is presented.The section Linocieroides is abandoned and united with section Osmanthus.     

双壳类的性转换现象及其机理探讨

生物的雌雄同体及性变现象，历来受科研人员关注，在脊椎动物中已有不少研究，在双壳类中虽然也有报道，但研究尚不深入。有关双壳类群体的性别构成，一般认为多为雌雄异体，如马氏珠母贝、栉江珧、企鹅珍珠贝、巴非蛤等；少数物种为雌雄同体，如海湾扇贝、光滑蓝蛤及某些牡蛎。但在雌雄异体种类的群体中，常常发现雌雄同体的个体以及在一定条件出现的性别转化现象。     

Bmp2 is essential for cardiac cushion epithelial-mesenchymal transition and myocardial patterning

Cardiac cushion development provides a valuable system to investigate epithelial to mesenchymal transition (EMT), a fundamental process in development and tumor progression. In the atrioventricular (AV) canal, endocardial cells lining the heart respond to a myocardial-derived signal, undergo EMT, and contribute to cushion mesenchyme. Here, we inactivated bone morphogenetic protein 2 (Bmp2) in the AV myocardium of mice. We show that Bmp2 has three functions in the AV canal: to enhance formation of the cardiac jelly, to induce endocardial EMT and to pattern the AV myocardium. Bmp2 is required for myocardial expression of Has2, a crucial component of the cardiac jelly matrix. During EMT, Bmp2 promotes expression of the basic helix-loop-helix factor Twist1, previously implicated in EMT in cancer metastases, and the homeobox genes Msx1 and Msx2. Deletion of the Bmp type 1A receptor, Bmpr1a, in endocardium also resulted in failed cushion formation, indicating that Bmp2 signals directly to cushion-forming endocardium to induce EMT. Lastly, we show that Bmp2 mutants failed to specify the AV myocardium with loss of Tbx2 expression uncovering a myocardial, planar signaling function for Bmp2. Our data indicate that Bmp2 has a crucial role in coordinating multiple aspects of AV canal morphogenesis.