齐墩果酸抗炎抗氧化研究进展

齐墩果酸是从植物中提取的一种天然有效成分,毒性低,具有广泛的药理作用,如抗炎、抗氧化等。由于其经济价值,已成为开发热点。本文就齐墩果酸在抗炎、抗氧化两方面的有关研究及其可能机制予以综述。     

Butanol Extract of Acanthopanax senticosus (Rupr. et Maxim.) Harms Alleviates Atherosclerosis in Apolipoprotein E-Deficient Mice Fed a High-Fat Diet

This study investigated the effect of butanol extract of AS (ASBUE) on atherosclerosis in apolipoprotein E-deficient (ApoE^−/−) mice. The mice were administered ASBUE (390 or 130 mg/kg/day) or rosuvastatin (RSV) via oral gavage for eight weeks. In ApoE^−/− mice, ASBUE suppressed the abnormal body weight gain and improved serum and liver biochemical indicators. ASBUE remarkably reduced the aortic plaque area, improved liver pathological conditions, and lipid metabolism abnormalities, and altered the intestinal microbiota structure in ApoE^−/− mice. In the vascular tissue of ASBUE-treated mice, P-IKKβ, P-NFκB, and P-IκBα levels tended to decrease, while IκB-α increased in high fat-diet-fed atherosclerotic mice. These findings demonstrated the anti-atherosclerotic potential of ASBUE, which is mediated by the interaction between the gut microbiota and lipid metabolism and regulated via the Nuclear Factor-kappa B (NF-κB) pathway. This work paves the groundwork for subsequent studies to develop innovative drugs to treat atherosclerosis.     

Development and validation of robust metabolism-related gene signature in the prognostic prediction of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumours worldwide. Given metabolic reprogramming in tumours was a crucial hallmark, several studies have demonstrated its value in the diagnostics and surveillance of malignant tumours. The present study aimed to identify a cluster of metabolism-related genes to construct a prediction model for the prognosis of HCC. Multiple cohorts of HCC cases (466 cases) from public datasets were included in the present analysis. (GEO cohort) After identifying a list of metabolism-related genes associated with prognosis, a risk score based on metabolism-related genes was formulated via the LASSO-Cox and LASSO-pcvl algorithms. According to the risk score, patients were stratified into low- and high-risk groups, and further analysis and validation were accordingly conducted. The results revealed that high-risk patients had a significantly worse 5-year overall survival (OS) than low-risk patients in the GEO cohort. (30.0% vs. 57.8%; hazard ratio [HR], 0.411; 95% confidence interval [95% CI], 0.302–0.651; p < 0.001) This observation was confirmed in the external TCGA-LIHC cohort. (34.5% vs. 54.4%; HR 0.452; 95% CI, 0.299–0.681; p < 0.001) To promote the predictive ability of the model, risk score, age, gender and tumour stage were integrated into a nomogram. According to the results of receiver operating characteristic curves and decision curves analysis, the nomogram score possessed a superior predictive ability than conventional factors, which indicate that the risk score combined with clinicopathological features was able to achieve a robust prediction for OS and improve the individualized clinical decision making of HCC patients. In conclusion, the metabolic genes related to OS were identified and developed a metabolism-based predictive model for HCC. Through a series of bioinformatics and statistical analyses, the predictive ability of the model was approved.     

猫后内侧上雪氏区视神经元对运动棒反应的取向和方向特征

猫后内侧上雪区（ｐｏｓｔｅｒｏｍｅｄｉａｌｌａｔｅｒａｌｓｕｐｒａｓｙｌｖｉａｎａｒｅａ,ＰＭＬＳ）的绝大多数神经元（１７１／２００）对运动棒的取向调谐,６２％（１２４／２００）细胞的取向调谐宽度（半高波宽）小于９０°：按方向选择性和取向选择性可分辨出几类特征明显的细胞类型：１、强取向和强方向选择性细胞;２、强取向调谐的双向选择细胞;３、弱取向调谐的强方向选择细胞;４、无取向无方向选择性细胞;以及５、特征不明显的或中间类型细胞。它们与最近光学记录揭示的鹰猴中颞叶视区（ｍｉｄｄｌｅｔｅｍｐｏｒａｌｖｉｓｕａｌａｒｅａ,ＭＴ）的组织有很好的吻合。     

四川55种鱼生活史型的研究

四川５５种鱼生活史型的研究刁晓明,罗一兵李波（西南农业大学水产系,重庆６３０７１６）（重庆大学计算机系,６３００００）ＬｉｆｅＨｉｓｔｏｒｙＰａｔｔｅｒｎｓｏｆ５５ＦｉｓｈＳｐｅｃｉｅｓｉｎＳｉｃｈｕａｎ￥ＤｉａｏＸｉａｏｍｉｎｇ;ＬｕｏＹｉｂｉｎｇ...     

Complementing amino acid substitutions within loop 6 of the alpha/beta-barrel active site influence the CO2/O2 specificity of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase

Photosynthesis-deficient mutant 45-3B of the green alga Chlamydomonas reinhardtii contains a chloroplast mutation that causes valine-331 to be replaced by alanine within the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase. This amino acid substitution occurs in loop 6 of the alpha/beta-barrel active site, three residues distant from catalytic lysine-334. The mutation reduces the specific activity of the enzyme and also reduces its CO2/O2 specificity factor by 42%, but the amount of holoenzyme is unaffected. In a previous study, an intragenic-suppressor mutation, named S40-9D, was selected that causes threonine-342 to be replaced by isoleucine, thereby increasing the CO2/O2 specificity of the mutant enzyme by 36%. To determine which other residues might be able to complement the original mutation, nine additional genetically independent revertants have now been analyzed. Another intragenic suppressor, represented by mutation S61-2J, causes glycine-344 to be replaced by serine. This change increases the CO2/O2 specificity of the mutant enzyme by 25%. Of the revertants recovered and analyzed, the mutant enzyme was improved only due to true reversion or by intragenic suppression mediated by substitutions at residues 342 or 344. Changes in the physical properties of the two pairs of complementing substitutions indicate that steric effects within loop 6 are responsible for the observed changes in the CO2/O2 specificity of the enzyme.     

Comprehensive profiling of accessible surface glycans of mammalian sperm using a lectin microarray

It is well known that cell surface glycans or glycocalyx play important roles in sperm motility, maturation and fertilization. A comprehensive profile of the sperm surface glycans will greatly facilitate both basic research (sperm glycobiology) and clinical studies, such as diagnostics of infertility. As a group of natural glycan binders, lectin is an ideal tool for cell surface glycan profiling. However, because of the lack of effective technology, only a few lectins have been tested for lectin-sperm binding profiles. To address this challenge, we have developed a procedure for high-throughput probing of mammalian sperm with 91 lectins on lectin microarrays. Normal sperm from human, boar, bull, goat and rabbit were collected and analyzed on the lectin microarrays. Positive bindings of a set of ~50 lectins were observed for all the sperm of 5 species, which indicated a wide range of glycans are on the surface of mammalian sperm. Species specific lectin bindings were also observed. Clustering analysis revealed that the distances of the five species according to the lectin binding profiles are consistent with that of the genome sequence based phylogenetic tree except for rabbit. The procedure that we established in this study could be generally applicable for sperm from other species or defect sperm from the same species. We believe the lectin binding profiles of the mammalian sperm that we established in this study are valuable for both basic research and clinical studies.     

A Cu-only superoxide dismutase from stripe rust fungi functions as a virulence factor deployed for counter defense against host-derived oxidative stress

Plants quickly accumulate reactive oxygen species (ROS) to resist against pathogen invasion, while pathogens strive to escape host immune surveillance by degrading ROS. However, the nature of the strategies that fungal pathogens adopt to counteract host-derived oxidative stress is manifold and requires deep investigation. In this study, a superoxide dismutase (SOD) from Puccinia striiformis f. sp. tritici (Pst) PsSOD2 with a signal peptide (SP) and the glycophosphatidyl inositol (GPI) anchor, strongly induced during infection, was analysed for its biological characteristics and potential role in wheat–Pst interactions. The results showed that PsSOD2 encodes a Cu-only SOD and responded to ROS treatment. Heterologous complementation assays in Saccharomyces cerevisiae suggest that the SP of PsSOD2 is functional for its secretion. Transient expression in Nicotiana benthamiana leaves revealed that PsSOD2 is localized to the plasma membrane. In addition, knockdown of PsSOD2 by host-induced gene silencing reduced Pst virulence and resulted in restricted hyphal development and increased ROS accumulation. In contrast, heterologous transient assays of PsSOD2 suppressed flg22-elicited ROS production. Taken together, our data indicate that PsSOD2, as a virulence factor, was induced and localized to the plasma membrane where it may function to scavenge host-derived ROS for promoting fungal infection.     

模拟氮沉降对长白山苔原灌草混合群落中植物光合特性的影响

由于草本植物持续上侵长白山灌木苔原,形成了强烈的灌草群落种间竞争。本研究以牛皮杜鹃-小叶章群落（Comm.Rhododendron aureum-Deyeuxia purpurea）为对象,根据小叶章的入侵程度设置4种盖度差异显著的样方（无、轻度、中度、重度入侵）,并设3个施氮水平（自然状态、添加11.8 kgN·hm^-2·a^-1及添加23.6 kgN·hm^-2·a^-1）,进行原位氮沉降模拟实验,监测灌木牛皮杜鹃和草本植物小叶章光合特性的差异和变化趋势,研究小叶章入侵苔原带的内在生理机制。结果显示：（1）小叶章净光合速率大于牛皮杜鹃,小叶章盖度越高、其叶绿素含量越高,而牛皮杜鹃叶绿素含量降低,随着小叶章入侵程度的增加,其净光合速率增强;（2）施氮可以提高牛皮杜鹃和小叶章的叶绿素含量和净光合速率,促进植物生长,但小叶章的增幅更大,从而增强了小叶章的竞争优势;（3）施氮和小叶章入侵具有复合作用,小叶章盖度越大,对其施氮导致小叶章净光合速率与叶绿素含量的增幅越大,而牛皮杜鹃的增幅减小。所以小叶章的成功入侵可能与其具有较高的净光合速率有关,并且施氮有利于提高小叶章的净光合速率,随着氮沉降的继续增加,更有利于小叶章的生长并提高其竞争力。