Compare the Effect of Eicosapentaenoic Acid and Oxidized Low-Density Lipoprotein on the Expression of CD36 and Peroxisome Proliferator-Activated Receptor Gamma

Background: There is evidence that CD36 promotes foam cell formation through internalizing oxidized LDL (ox-LDL) into macrophages; therefore, it plays a key role in pathogenesis of atherosclerosis. In addition, CD36 expression seems to be mediated by nuclear receptor peroxisome proliferator-activated receptor gamma (PPAR-γ). The aim of the present study was to evaluate and compare the effect of PPAR-γ ligands, eicosapentaenoic acid (EPA) as an anti-atherogenic factor and ox-LDL as an atherogenic factor on CD36 expression. Mechanism of PPAR-γ action and its ligands in CD36 expression were also investigated. Methods: Raw 264.7 macrophage cell line was treated with ox-LDL (100 and 150 μg protein/LDL) and EPA (100 and 200 μM) for 24 and 48 hours in absence or presence of PPAR-γ inhibitor, T0070907. Quantitative real-time PCR and Western-blotting were used for analysis of gene and protein expression, respectively. Results: Raw 264.7 exposures to ox-LDL and EPA resulted in increased expression of CD36 mRNA and protein; however, mRNA and PPAR-γ protein were not up-regulated significantly. Pre-incubation of cells with T0070907 led to decreased expression of CD36 when treated with ox-LDL and EPA. Conclusion: It was confirmed that both EPA and ox-LDL increased CD36 expression but not PPAR-γ, and also co-treatment with PPAR-γ inhibitor decreased CD36 expression. We concluded that up-regulation of CD36 depends on PPAR-γ activation and is not related to increased expression of PPAR-γ. Induction of CD36 by EPA showed that CD36 suppression is not the means by which ω-3 fatty acids (EPA) provide protection against formation of atherosclerotic plaque. Key Words: Atherosclerosis, proliferator-activated receptor gamma (PPAR-γ), Oxidized low density lipoprotein (ox-LDL), Eicosapentaenoic acid (EPA)     

不同改良措施对碱化土壤特性及玉米生长的影响

2018年在西辽河平原灌区碱化土壤实施玉米秸秆还田基础上配施中农绿康腐熟剂和人元秸秆腐熟剂、混沙和混糠醛渣试验,测定春玉米产量、玉米根系特性及土壤速效养分和酶活性,研究不同改良措施对碱化土壤特性及玉米生长的影响.结果 表明,与盐碱地常规掺混沙子处理比较,在玉米秸秆还田基础上,配施中农绿康和人元秸秆腐熟剂处理均能显著提高...     

碱性盐胁迫对燕麦矿质离子吸收与分配的影响

为探讨燕麦耐碱性与矿质离子的关系,通过盆栽试验,将碱性盐Na2CO3、NaHCO3按摩尔比1∶1混合设置不同浓度(0、50和100mmol·L-1)胁迫处理,分析燕麦耐碱性品种vao-9和碱敏感性品种白燕5号根、茎、叶对Na+、K+、Ca2+、Mg2+、Fe2+、Cu2+、Zn2+的吸收及分配规律。结果表明,碱性盐胁迫下2个品种根、茎、叶中Na+含量增加,K+、Cu2+含量下降;Ca2+、Mg2+含量在根中增加,在茎、叶中下降,Fe2+、Zn2+含量在不同胁迫程度下和不同器官中变化不同。与白燕5号相比,vao-9吸收的Na+总量较低,K+、Ca2+、Cu2+总量较高,Mg2+、Fe2+、Zn2+总量变化不大。在胁迫浓度达到100mmol·L-1时,vao-9茎中截留Na+,叶片中较K+、Ca2+、Mg2+、Fe2+、Cu2+和Zn2+分配较多,而白燕5号叶片中积累Na+较多,茎中积累K+较多,根中积累Ca2+、Mg2+、Fe2+、Cu2+、Zn2+较多,从而使碱性盐胁迫下vao-9较白燕5号叶片中保持的Na+/K+、Na+/Ca2+和Na+/Mg2+低。可见,在高浓度碱性盐胁迫下vao-9茎中区域化Na+,选择吸收K+、Ca2+、Cu2+,并在叶片中分配较多的矿质离子来保持燕麦体内离子平衡,以适应盐碱胁迫。     

海北州草地蝗虫危害监测

海北州是草地蝗虫灾害频发的地区之一,每年的蝗虫危害面积广、密度高、危害严重。本文从蝗虫的发生数量、危害程度、损失状况等方面进行了详细的调查,并结合实际,对草原蝗虫的生态学特性进行了分析研究,为今后更好的开展草地虫害监测、提高预测预报准确率提供了依据。