基于UPLC-MS/MS技术的野生及栽培韭菜籽的代谢组学研究

多星韭为贵州省赫章县喀斯特地貌区重要的野生植物资源之一,具有较高的开发利用价值。为分析野生多星韭(Allium wallichii )籽与栽培韭菜(A. tuberosum)籽代谢产物差异及其通路,该研究利用UPLC-MS/MS物质分离鉴定技术,对2种韭籽化学成分进行广泛靶向代谢组学分析。结果表明:(1)共检测到782种代谢产物。(2)主成分分析(PCA)显示样本间存在差异,正交偏最小二乘判别分析(OPLS-DA)共筛选出12类显著变化(P<0.05,VIP≥1)的差异代谢物,涉及492种,其中上调和下调幅度在前20的代谢物包括黄酮、甾体皂苷、黄酮醇、酚酸类、异黄酮、游离脂肪酸、三萜皂苷、生物碱、吲哚类生物碱、氨基酸及其衍生物等。(3)KEGG注释到84条差异代谢通路,其中差异代谢物显著富集(P<0.01)通路4条,此外还构建了未注释到的显著差异代谢物甾体皂苷的生物合成通路。该研究结果为韭籽有效成分代谢途径解析及药理活性物质研究提供了参考,也为赫章县野生多星韭的开发保护与多元化利用提供了新思路。     

濒危植物大别山五针松根际细菌群落特征与功能分析

植物根际微生物群落对植物健康生长有重要影响, 每种植物根际都有其特定的微生物群落。大别山五针松(Pinus dabeshanensis)被国际自然保护联盟列为濒危物种, 具有重要研究价值。该研究采用16S rRNA高通量测序技术与生物信息学方法, 对濒危植物大别山五针松根际细菌群落特征与功能进行分析。结果表明, 大别山五针松根际微生物的主要种类为变形菌门、放线菌门、酸杆菌门和疣微菌门。网络分析表明, 大别山五针松根际细菌类群存在显著相关性, 其中Bryobacter属、Bradyrhizobium属和未定义的TK10属是互作网络中的重要节点。PICRUSt1功能预测表明其微生物组功能主要为氨基酸运输和代谢、细胞壁/膜/膜生物发生以及能量产生和转换。FAPROTAX功能预测表明, 大别山五针松根际富含的优势菌群具有丰富的化学异养、纤维素水解、需氧化学异养和固氮功能, 其对植物生长发育具有重要作用。研究结果可为培育健康的大别山五针松根际微生物菌群及微生物资源的开发利用提供重要依据。     

Glycosylation of dodecyl 2-acetamido-2-deoxy-beta-D-glucopyranoside and dodecyl beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-beta-D-glucopyranoside as saccharide primers in cells

Syntheses of oligosaccharides expressed on cells are indispensable for the improvement of the functional analyses of the oligosaccharides and their applications. We are developing saccharide primers for synthesizing oligosaccharides using living cells. In this study, dodecyl 2-acetamido-2-deoxy-beta-D-glucopyranoside (GlcNAc-C12) and dodecyl beta-D-galactopyranosyl-(1-->4)-2-acetamido-2-deoxy-beta-D-glucopyranoside (LacNAc-C12) were examined for their abilities to prime the syntheses of neolacto-series oligosaccharides in HL60 cells. When GlcNAc-C12 was incubated with HL60 cells in serum-free medium for 2 days, 14 kinds of glycosylated products were collected from the culture medium. They were separated by high-performance liquid chromatography. The sequences of the products were determined to be neolacto-series oligosaccharides including Lewis(X), sialyl Lewis(X), polylactosamine, and sialylpolylactosamine by mass spectrometry. GlcNAc-C12 was also glycosylated by B16 cells and gave sialyllactosamine. Furthermore, LacNAc-C12 gave similar glycosylated products to GlcNAc-C12.     

Surface modification of polycaprolactone membrane via aminolysis and biomacromolecule immobilization for promoting cytocompatibility of human endothelial cells

Amino groups were covalently introduced onto a polycaprolactone (PCL) surface by the reaction between 1,6-hexanediamine and the ester groups of PCL. The occurrence of the aminolysis and the introduction of free NH(2) groups were verified qualitatively by fluorescence spectroscopy, where rhodamine B isothiocyanate was employed to label NH(2) groups, and quantitatively by absorbance spectroscopy, where ninhydrin was used to react with NH(2) to generate a blue product. Due to the presence of deep pores on the PCL membrane, the aminolysis reaction could penetrate as deep as 50 microm to yield NH(2) density as high as 2 x 10(-7) mol/cm(2). By use of the NH(2) groups as active sites, biocompatible macromolecules such as gelatin, chitosan, or collagen were further immobilized on the aminolyzed PCL membrane via a cross-linking agent, glutaraldehyde. X-ray photoelectron spectroscopy (XPS) and surface wettability measurements confirmed the coupling of the biomacromolecules. The endothelial cell culture proved that the cytocompatibility of the aminolyzed PCL was improved slightly regardless of the NH(2) amount on the surface. After immobilization of the biomacromolecules, however, the cell attachment and proliferation ratios were obviously improved and the cells showed a similar morphology to those on tissue culture polystyrene. Measurement of the von Willebrand factor (vWF) secreted by these endothelial cells (ECs) verified the endothelial function. Hence, a better EC-compatible PCL was produced.     

Intracellular calcium waves in bone cell networks under single cell nanoindentation

In this study, bone cells were successfully cultured into a micropatterned network with dimensions close to that of in vivo osteocyte networks using microcontact printing and self-assembled monolyers (SAMs). The optimal geometric parameters for the formation of these networks were determined in terms of circle diameters and line widths. Bone cells patterned in these networks were also able to form gap junctions with each other, shown by immunofluorescent staining for the gap junction protein connexin 43, as well as the transfer of gap-junction permeable calcein-AM dye. We have demonstrated for the first time, that the intracellular calcium response of a single bone cell indented in this bone cell network, can be transmitted to neighboring bone cells through multiple calcium waves. Furthermore, the propagation of these calcium waves was diminished with increased cell separation distance. Thus, this study provides new experimental data that support the idea of osteocyte network memory of mechanical loading similar to memory in neural networks.     

Phytoplankton biomass and production in northern South China Sea during summer: Influenced by Pearl River discharge and coastal upwelling

Chlorophyll a and primary production were studied in northern South China Sea during summer from 2007 to 2008. Microplankton dominated total phytoplankton biomass in the coast, while picoplankton dominated in the offshore. Algae bloom caused by Thalassionema nitzschioides was found at the subsurface of upwelling regions (D2, C2) in 2008, and maximum of phytoplankton abundance reached 1.58 × 10⁶ ind L^?1. Integrated primary production ranged from 189.3 to 976.2 mg m^?2 d^?1 in 2007, and ranged from 652.1 to 6601 mg m^?2 d^?1 in 2008. PP showed positive relationship with IPP (p < 0.01) and negative relationship with SST (p < 0.05). Coastal upwelling and Pearl River discharge sustained high PP, and played important role in regulating the phytoplankton biomass and production.     

The protective effect of sinapic acid in osteoarthritis: In vitro and in vivo studies

The anti‐inflammatory effect of sinapic acid (SA) has been reported in several studies. However, whether SA has the same effect on osteoarthritis (OA) has yet to be clearly elucidated. We designed a series of in vitro and in vivo procedures to verify the above conjecture. Compared with controls, SA‐pretreated human chondrocytes showed lower levels of interleukin (IL)‐1β‐induced IL‐6, prostaglandin E2 (PGE2), nitric oxide (NO) and tumour necrosis factor‐α (TNF‐α) in vitro. Meanwhile, SA could also reverse the degradation of type II collage and aggrecan, as well as the overproduction of matrix metalloproteinase‐9 (MMP‐9) and matrix metalloproteinase‐13 (MMP‐13), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)‐2 and a disintegrin and metalloproteinase thrombospondin motifs (ADAMTS)‐5. Furthermore, activation of nuclear factor κB (NF‐κB), which was induced by IL‐1β, was also inhibited by SA through the pathway of nuclear factor‐erythroid 2‐related factor‐2 (Nrf2)/heme oxygenase 1. In vivo, SA could delay the progress of mice OA models. We propose that SA may be applied as a potential therapeutic drug in OA treatment.