抗山羊ΔfosB基因表达产物抗体的制备及应用

ΔfosB是fosB基因的自然截短型,稳定存在于许多组织中,在脂肪细胞和成骨细胞的形成和分化中起到重要作用。ΔFosB蛋白可能与钙在骨和乳腺中的代谢有关,并且调控钙从骨向乳腺转移的信号通路。将奶山羊的ΔfosB基因亚克隆到pET32a载体得到pET32a-ΔfosB原核表达载体,IPTG诱导其在大肠杆菌中表达,纯化融合蛋白免疫兔子制备多克隆抗体。ELISA检测显示抗体效价达1:51200,Western blotting结果显示制备的抗体能特异性检测原核表达的ΔFosB蛋白以及在HEK-293细胞中表达的ΔFosB蛋白。进一步的组织差异表达检测表明ΔFosB在山羊的乳腺、骨髓、脑髓、肌肉、心脏、肝和肺组织中均有表达。     

Probing of contacts between EcoRII DNA methyltransferase and DNA using substrate analogs and molecular modeling

To determine the molecular mechanism of DNA recognition and catalysis by EcoRII DNA-methyltransferase (M.EcoRII) binding and methylation by the enzyme of 14-mer substrate analogs containing 2-aminopurine or 1',2'-dideoxy-D-ribofuranose in the M.EcoRII recognition site have been studied. Efficiencies of methylation and DNA binding affinities depend on the location of modified nucleoside residues within the M.EcoRII recognition site. A structural model of M.EcoRII in complex with substrate DNA and cofactor analog S-adenosyl-L-homocysteine (AdoHcy) was built using the previously solved structures of Hhal and HaeIII DNA-methyltransferases as templates. The model was constructed according to the recently developed "Frankenstein's monster" approach. Based on the model, amino acid residues taking part in interactions with DNA were predicted. Besides, based on both theoretical and experimental data obtained the groups of atoms of the heterocyclic bases within the M.EcoRII recognition site presumably involved in interaction with the enzyme were proposed.     

褐藻寡糖抗环磷酰胺诱导蚕豆根尖的细胞遗传毒性

采用蚕豆根尖细胞的微核试验和染色体畸变试验方法,测定不同浓度的褐藻寡糖对环磷酰胺(cyclophosphamide,CP)诱导的蚕豆根尖细胞的微核率、有丝分裂指数和染色体畸变率的影响。结果表明:褐藻寡糖能有效抑制环磷酰胺诱导的蚕豆根尖细胞微核的产生,即在一定浓度范围内,微核率随褐藻寡糖处理浓度的降低而减少,但低于一定浓度后反而呈上升趋势;不同浓度的褐藻寡糖均可使蚕豆根尖细胞有丝分裂指数增大;褐藻寡糖还能有效降低蚕豆根尖细胞染色体畸变率。因此,褐藻寡糖对蚕豆根尖细胞具有明显的诱抗活性和调节细胞分裂生长的效应。     

The design, synthesis, and biological evaluation of novel substituted purines as HIV-1 Tat-TAR inhibitors

A series of novel substituted purines containing a side chain with a terminal amino or guanidyl group were designed and synthesized as HIV-1 Tat-TAR inhibitors. All the compounds could effectively block the TAR transactivation in human 293T cells with the CAT expression percentage ranging from 34.4% to 65.7% and showed high antiviral effects with low cytotoxicities in inhibiting the formation of SIV-induced syncytium in CEM174 cells. Molecular modeling studies by Auto-dock process suggest that the compounds bind to TAR RNA in two different modes.     

Tau Monoclonal Antibody Generation Based on Humanized Yeast Models: IMPACT ON TAU OLIGOMERIZATION AND DIAGNOSTICS*

A link between Tau phosphorylation and aggregation has been shown in different models for Alzheimer disease, including yeast. We used human Tau purified from yeast models to generate new monoclonal antibodies, of which three were further characterized. The first antibody, ADx201, binds the Tau proline-rich region independently of the phosphorylation status, whereas the second, ADx215, detects an epitope formed by the Tau N terminus when Tau is not phosphorylated at Tyr¹⁸. For the third antibody, ADx210, the binding site could not be determined because its epitope is probably conformational. All three antibodies stained tangle-like structures in different brain sections of THY-Tau22 transgenic mice and Alzheimer patients, and ADx201 and ADx210 also detected neuritic plaques in the cortex of the patient brains. In hippocampal homogenates from THY-Tau22 mice and cortex homogenates obtained from Alzheimer patients, ADx215 consistently stained specific low order Tau oligomers in diseased brain, which in size correspond to Tau dimers. ADx201 and ADx210 additionally reacted to higher order Tau oligomers and presumed prefibrillar structures in the patient samples. Our data further suggest that formation of the low order Tau oligomers marks an early disease stage that is initiated by Tau phosphorylation at N-terminal sites. Formation of higher order oligomers appears to require additional phosphorylation in the C terminus of Tau. When used to assess Tau levels in human cerebrospinal fluid, the antibodies permitted us to discriminate patients with Alzheimer disease or other dementia like vascular dementia, indicative that these antibodies hold promising diagnostic potential.     

Epidermal fatty acid‐binding protein protects nerve growth factor‐differentiated PC12 cells from lipotoxic injury

Epidermal fatty acid‐binding protein (E‐FABP/FABP5/DA11) binds and transport long‐chain fatty acids in the cytoplasm and may play a protecting role during neuronal injury. We examined whether E‐FABP protects nerve growth factor‐differentiated PC12 cells (NGFDPC12 cells) from lipotoxic injury observed after palmitic acid (C16:0; PAM) overload. NGFDPC12 cells cultures treated with PAM/bovine serum albumin at 0.3 mM/0.15 mM show PAM‐induced lipotoxicity (PAM‐LTx) and apoptosis. The apoptosis was preceded by a cellular accumulation of reactive oxygen species (ROS) and higher levels of E‐FABP. Antioxidants MCI‐186 and N‐acetyl cysteine prevented E‐FABP's induction in expression by PAM‐LTx, while tert‐butyl hydroperoxide increased ROS and E‐FABP expression. Non‐metabolized methyl ester of PAM, methyl palmitic acid (mPAM), failed to increase cellular ROS, E‐FABP gene expression, or trigger apoptosis. Treatment of NGFDPC12 cultures with siE‐FABP showed reduced E‐FABP levels correlating with higher accumulation of ROS and cell death after exposure to PAM. In contrast, increasing E‐FABP cellular levels by pre‐loading the cells with recombinant E‐FABP diminished the PAM‐induced ROS and cell death. Finally, agonists for PPARβ (GW0742) or PPARγ (GW1929) increased E‐FABP expression and enhanced the resistance of NGFDPC12 cells to PAM‐LTx. We conclude that E‐FABP protects NGFDPC12 cells from lipotoxic injury through mechanisms that involve reduction of ROS.

     

A revised classification of the genus Matrona Selys, 1853 using molecular and morphological methods (Odonata: Calopterygidae)

An extensive review of the genus Matrona is presented based on mitochondrial (COI) and nuclear (ITS) sequences from 150 samples which cover all the known taxa of this genus. The separation of two main clades (oreades group: M. oreades, M. corephaea and M. taoi; basilaris group: M. basilaris, M. nigripectus, M. cyanoptera, M. japonica and M. annina) is strongly supported. The classification of all traditional recognized species is confirmed. The Hainan population separates very well from mainland M. basilaris populations, which is also confirmed by geometric morphometric analysis of wing shape. Given the implications of the molecular analysis the genus Matrona is grouped into two subgenera: subgen. Matrona (type species M. basilaris) and D ivortia subgen. nov. (type species M. oreades). A new species, M . ( M .) mazu sp. nov. , from Hainan is described. Brief taxonomic notes on the nine recognized species of the genus are given. Lectotype designations of M. basilaris and M. nigripectus are published. © 2015 The Linnean Society of London     

Predicting the wetland distributions under climate warming in the Great Xing’an Mountains,northeastern China

The wetland ecosystem is particularly vulnerable to hydrological and climate changes. The Great Xing’an Mountain is such a region in China that has a large area of wetlands with rare human disturbance. The predictions of the global circulation model CGCM3 (the third-generation coupled global climate model from the Canadian Centre for Climate Modeling and Analysis) indicated that the temperature in The Great Xing’an Mountain will rise by 2–4°C over the next 100 years. This paper predicts the potential distributions of wetlands in this area under the current and warming climate conditions. This predication was performed by the Random Forests model, with 18 environmental variables, which will reflect the climate and topography conditions. The model has been proven to have a great prediction ability. The wetland distributions are primarily topography-driven in the Great Xing’an Mountains. Mean annual temperature, warmness index, and potential evapotranspiration ratio are the most important climatic factors in wetland distributions. The model predictions for three future climate scenarios show that the wetland area tends to decrease, and higher emission will also cause more drastic shrinkage of wetland distributions. About 30% of the wetland area will disappear by 2050. The area will decrease 62.47, 76.90, and 85.83%, respectively, under CGCM3-B1, CGCM3-A1B, and CGCM3-A2 by 2100. As for spatial allocation, wetlands may begin to disappear from the sides to the center and south to north under a warming climate. Under CGCM3-B1, the loss of wetlands may mainly occur in the south hills with flatter terrain, and some may occur in the north hills and intermontane plains. Under CGCM3-A1B, severe vanish of wetlands is predicted. Under CGCM3-A2, only a small area of wetlands may remain in the north of the high mountains.