Clarithromycin suppresses induction of monocyte chemoattractant protein-1 and matrix metalloproteinase-9 and improves pathological changes in the lungs and heart of mice infected with influenza A virus

The influenza A virus (IAV)–cytokine–trypsin/matrix metalloproteinase-9 (MMP-9) cycle is one of the important mechanisms of multiple organ failure in severe influenza. Clarithromycin, a macrolide antibiotic, has immune modulatory and anti-inflammatory effects. We analyzed the effects of clarithromycin on the induction of chemokines, cytokines, MMP-9, trypsin, vascular hyper-permeability and inflammatory aggravation in mice with IAV infection. IAV/Puerto Rico/8/34(H1N1) infection increased the levels of monocyte chemoattractant protein-1 (MCP-1) and cytokines in serum, and MMP-9 and trypsin in serum and/or the lungs and heart. Clarithromycin significantly suppressed the induction of serum MCP-1 and MMP-9 and vascular hyperpermeability in these organs in the early phase of infection, but did not suppress the induction of trypsin, IL-6 or IFN-γ. Histopathological examination showed that clarithromycin tended to reduce inflammatory cell accumulation in the lungs and heart. These results suggest that clarithromycin suppresses infection-related inflammation and reduces vascular hyperpermeability by suppressing the induction of MCP-1 and MMP-9.     

人源H7N9流感病毒促进Ⅰ型干扰素产生机制的研究

为阐明不同来源H7N9流感病毒诱导Ⅰ型干扰素(IFN-Ⅰ)产生水平差异及其机制,本研究选取人源流感病毒A/Anhui/1/2013(AH/1)株和禽源流感病毒A/Pigeon/Shanghai/S1421/2013(PG/S1421)株作为模式病毒株,利用C57BL/6小鼠进行致病性试验。结果显示,AH/1株感染可以致小鼠发病死亡,而PG/S1421株则不会致小鼠发病。采用间接免疫荧光试验和流式细胞试验分别对两株病毒在A549细胞和小鼠腹腔巨噬细胞中的感染效率进行检测,结果显示两株病毒在两种细胞中的感染效率无显著差异。将该两株病毒分别感染小鼠腹腔巨噬细胞,在感染后不同时间点收集培养上清,并裂解细胞收取细胞总蛋白。采用ELISA方法对细胞培养上清IFN-Ⅰ含量进行测定。结果显示,感染后不同时间,AH/1株和PG/S1421株均可以诱导IFN-Ⅰ产生,但相较于PG/S1421株,AH/1株感染可以诱导细胞产生更多的IFN-Ⅰ;利用western blot对细胞总蛋白中IFN-Ⅰ产生信号通路的上游感受器分子视黄酸诱导基因Ⅰ(RIG-Ⅰ)的表达水平进行检测。结果显示,在PG/S1421株感染细胞的12 h内,胞内RIG-Ⅰ分子的表达量无显著变化,而AH/1株感染后,胞内RIG-Ⅰ分子的表达量增加,并且表达量随时间延长而上升。以上试验结果表明,AH/1株感染可以通过上调RIG-Ⅰ表达进而诱导宿主细胞产生更多IFN-Ⅰ。本研究阐明了人源H7N9流感病毒促进IFN-Ⅰ产生的初步机制,为进一步解析人源H7N9流感病毒促进IFN-Ⅰ产生的精细分子机制以及免疫逃逸机制奠定了基础,为H7N9流感防控提供参考依据。     

H5、H7和H9亚型禽流感病毒四重荧光RT-PCR检测方法的建立与应用

旨在提高对禽流感病毒（avian influenza virus，AIV）检测效率，及时发现疫病。本研究通过分析M基因以及H5、H7和H9亚型的HA基因序列保守区域，设计并合成了相关探针和引物，建立了禽流感病毒（AIV）四重荧光RT-PCR检测方法，该方法可在检测禽流感病毒（AIV）的同时，确定病原是否为H5、H7和H9亚型。结果显示，该检测方法耗时短、特异性好、检测下限达到10^-5 ng·μL^-1。采用该方法检测临床采集的13个活禽交易市场的384份禽咽喉和泄殖腔双拭子样品，经检测，其中有60份样品为流感病毒阳性，且全部是H9亚型，该结果与行业标准方法（NY/T 772—2013）检测结果一致，κ值为1（P<0.001）。本方法能实现对禽流感病毒及H5、H7和H9亚型的高通量快速检测，将在AIV快速检测中发挥重要作用。     

Mass spectrometry imaging of BARLEYmax fructooligosaccharides

BARLEYmax is a novel hull-less barley cultivar lacking activity of a key enzyme required for starch synthesis (SSIIa), resulting in a grain with reduced total starch, higher dietary fiber, and higher fructan content. In this study, we examined the quantitative differences in fructan among 2 hull-less barley lines (BARLEYmax and Mannenboshi) and 2 peeled barley lines (Glutinous barley rice and Hindmarsh). We found that BARLEYmax had a higher fructan content, particularly 2 types of fructooligosaccharides (FOS), namely kestose and nystose, the important components of fructan that have some beneficial effects for human health. We established a mass spectrometry imaging (MSI) method to further investigate the content and localization of FOS in the barley lines. We found that kestose, nystose, and fructosyl-nystose showed increased molecular ion intensities in BARLEYmax compared with those in other barley lines. These results confirmed that the loss of SSIIa activity in BARLEYmax leads to a decrease in starch in the cytoplasm and an increase in fructan in the vacuole as an energy store. Overall, these findings demonstrate that MSI analysis is helpful for understanding FOS localization in cereal grains and for visual comparison among matured grains.     

黔东南小香羊GDF9基因遗传变异分析

采用直接测序法检测GDF9基因在黔东南小香羊群体中的单核苷酸多态性。结果表明：在GDF9基因外显子2的550位碱基处发生了突变（A→C）并导致组氨酸突变为脯氨酸;试验检测到AA型、Aa型和aa型3种基因型;A等位基因频率为0．6667,a等位基因频率为0．3334。     

金丝桃素体外抗H9N2亚型禽流感病毒活性研究

研究金丝桃素体外抗H9N2亚型禽流感病毒的活性。用MTT法观察金丝桃素预防、治疗、以及体外直接作用15 min 4种给药方式对感染H9N2亚型禽流感病毒的细胞的保护效果,以及用荧光酶标法测定金丝桃素对禽流感病毒神经氨酸酶的抑制活性。结果表明,金丝桃素的4种给药方式在体外对感染禽流感病毒的细胞的的保护率分别为6.43%、5.31%、39.89%、69.04%。金丝桃素对禽流感病毒神经氨酸酶活性的抑制,IC50为0.58 mg/mL。表明金丝桃素对感染H9N2亚型禽流感病毒的细胞有一定保护的作用,且对神经氨酸酶的活性有较显著的抑制作用。     

Reduced expression of voltage-gated chloride channel genes in Caenorhabditis elegans: Implications for the mode of action of chloride channel-directed nematicides

Caenorhabditis elegans nematodes (fourth-stage larvae) were exposed for 24 h to long (4 μg/μl) or short (5 μg/μl) double-stranded RNA (dsRNA) of two voltage-gated chloride channel (VGCC) genes, ceclc-1 and ceclc-2, coding for two VGCC proteins, CeClC-1 and CeClC-2. The treatments reduced expression of these genes in F₁ progeny in a time- and concentration-dependent manner. Progeny with reduced expression of ceclc-2 (but not ceclc-1) showed significant phenotypic effects, such as increased pharyngeal contractions and decreased locomotion, which were maximal in 48 h old worms. Generally, there was little effect on the worms when expression of ceclc-1 alone was reduced. F₁ progeny with reduced expression of both ceclc-1 and ceclc-2 had a higher percentage showing affected locomotion than were present with reduced expression of ceclc-2 alone, whereas the increase in frequency of pharyngeal contractions was not different from that obtained with reduced expression of ceclc-2 alone. These phenotypic effects were consistent with the known expression patterns of ceclc-1 and ceclc-2 in C. elegans tissues. A strong negative correlation was observed between in vitro concentration of long dsRNA and ceclc-2 expression level, as well as between ceclc-2 expression level and corresponding phenotypic effects. The effects of dsRNA exposure are similar to previous studies in which 24-h incubation in 50 ppm of anion transporter (AT) blockers DIDS, 9-AC, IAA-94, or NPPB increased pharyngeal contractions and the proportion of nematodes exhibiting impaired locomotion. These findings confirm that the principal mechanism of nematicidal activity of AT blockers may arise from the inhibition of CeClC-2.     

柳窿桉9号引种栽培适应性研究

在福建霞浦、仙游、永泰、南平延平区、邵武市、永安市和上杭县开展柳窿桉9号引种适应性试验研究,结果表明:柳窿桉9号适应性和速生性较强,在一般立地条件下造林(Ⅲ类地)成活率可达95%以上,中龄林保存率达85%左右。其速生性虽略比尾巨桉DH32-29差,但1年生平均树高可达2.0 m以上,2年生树高、胸径分别可达5.0 m、5.0 cm以上,尤其在低海拔山地不受冻或轻微受冻的情况下,其速生性较为明显;柳窿桉9号树干通直、径粗,抗风、抗旱和抗病虫害能力均较强。但柳窿桉9号对低温极为敏感,耐寒性有限,只可耐-2.0~-2.5℃的低温,在闽西北地区受冻几率大,在闽东南地区海拔300 m以下的山地种植受冻较轻,可以恢复正常生长。该无性系在福建中亚热带极端低温不低于-3℃的区域低海拔山地有种植前景,尤其适合闽东南沿海海拔300 m以下的山地栽培。