Effect of DNA methylation of miR-30a-5p promoter region on hepatic injury induced by homocysteine

AIM: To explore the role of DNA methylation of microRNA-30a-5p(miR-30a-5p) promoter region in hepatic injury. METHODS: Four-week-old normal mice and cystathionine β-synthase (CBS) single gene knockout mice were used and divided into normal (CBS^+/+, n=12) group and single gene knockout (CBS^+/-, n=12) group, and the mice were fed with high methionine diet for 8 weeks. HL-7702 hepatic cells were routinely cultured in vitro and divided into control group, homocysteine (Hcy) group and Hcy+5-azacytidne (AZC) group. Serum Hcy, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were measured by automatic biochemical analyzer. The levels of ALT and AST in the cells culture medium were determined by the microplate method. Hepatic injury in the mice were observed with HE staining. Cell viability staining was used to measure the viability of hepatocytes. RT-qPCR was used to detect the expression of miR-30a-5p in the liver tissues and hepatocytes. The correlation between the expression of miR-30a-5p and serum ALT and AST levels was analyzed by Pearson correlation analysis. DNA methylation level of miR-30a-5p promoter region in the liver tissues and hepatocytes was detected by nested landing methylation-specific PCR (nMS-PCR). RESULTS: Compared with the CBS^+/+ mice, the serum levels of Hcy, ALT and AST in the CBS^+/- mice were significantly increased (P < 0.05). HE staining showed the hepatocyte swelling and nuclear fragmentation and dissolution. The expression level of miR-30a-5p in the liver tissues was decreased (P < 0.01). Besides, the expression level of miR-30a-5p in the mice was negatively correlated with serum ALT and AST levels (r²=0.4557, P=0.0003, r²=0.4626, P=0.0003), and the DNA methylation of miR-30a-5p promoter region was increased (P < 0.01). In the HL-7702 cells, compared with control group,the ALT and AST levels were increased in Hcy group (P < 0.05, P < 0.01), and the cell viability was remarkablely decreased. DNA methylation of miR-30a-5p promoter region was increased (P < 0.01), which decreased after treated the cells with AZC (P < 0.05), while the expression level of miR-30a-5p in the cells was increased (P < 0.05). CONCLUSION: Hypermethylation of miR-30a-5p promoter region may play an important role in hepatic injury.     

Autophagy induces mitochondrial dysfunction in neurons from neonatal rats with hypoxic ischemic encephalopathy

AIM: To explore the influence of autophagy on the induction of mitochondrial dysfunction in the neurons in a neonatal rat hypoxic ischemic encephalopathy (HIE) model. METHODS: Ten-day-old rat pups (n=30) were randomly divided into sham group and model group. The rats in the latter group were subject to hypoxia-ischemia treatment via unilateral common carotid artery ligation. The rats were sacrificed for brain pathological examination, and the protein levels of cleaved caspase-3 and LC3B-II were detected by immunohistochemical analysis. For the in vitro experiments, the autophagy of primarily cultured rat neurons was observed after hypoxia, and Western blot and mitochondrial function testing were also performed. RESULTS: Compare with sham group, the hypoxia-ischemia treatment caused atrophy and apoptosis of neurons, and ventricular area enlargement of rat brains. Immunohistochemical results demonstrated significantly higher levels of apoptosis- and autophagy-associated proteins, such as cleaved caspase-3 and LC3B-II (P<0.01). In vitro experiments demonstrated that hypoxia induced autophagy and apoptosis in the neurons. Compared with sham group, there were higher levels of reactive oxygen species and mitochondrial superoxide, and lower mitochondrial membrane potential in the model group (P<0.01). CONCLUSION: In neonatal HIE rat model, the hypoxia-induced mitochondrial dysfunction is related to apoptosis and autophagy. It will provide a new idea for administration of autopahgy inducer agents in treatment of HIE.     

Role of IP3R in LH-EGFR-induced mouse oocyte meiotic resumption

AIM: To explore the effect of inositol 1, 4, 5-trisposphate receptor (IP₃R) in luteinizing hormone-epidermal growth factor receptor (LH-EGFR)-induced oocyte meiotic resumption. METHODS: Models of mouse cumulus-oocyte complexs (COCs) culture and follicle culture in vitro were generated to study the effects of 2-aminoethyl diphenyl borate (2-APB) and heparin (IP₃R specific inhibitors) on LH/EGF-induced oocyte meiotic resumption and EGF-induced cumulus cell expansion. Real-time PCR was used to detect the mRNA expression of cumulus expansion-related factors. The changes of the intracellular calcium level were monitored using Fluo 3-AM, and the cGMP level was measured by ELISA. RESULTS: The inhibitors of IP₃R, 2-APB and heparin, dramatically reversed EGF-induced oocyte maturation (P<0.05) and decreased cGMP levels in COCs (P<0.05). In addition, 2-APB and heparin reversed EGF-induced cumulus expansion, and significantly inhibited EGF-induced cumulus expansion-related factor expression (P<0.05). The activation of IP₃R increased intracellular calcium level, and the study found that 2-APB and heparin dramatically reversed EGF-induced elevation of calcium level in cumulus cells (P<0.05). Follicular culture in vitro showed that 2-APB and heparin significantly reversed the LH-induced oocyte maturation (P<0.05). CONCLUSION: LH-EGFR signaling pathway increases calcium level in cumulus cells through IP₃R, resulting in meiotic resumption.     

Effects of cardiac contractility modulation on ventricular electrical remodeling in rabbits with chronic heart failure

AIM: To investigate the effects of cardiac contractility modulation (CCM) on ventricular electrical remodeling in a rabbit model of chronic heart failure. METHODS: The rabbits were divided into sham group, heart failure(HF) group and HF+ CCM group. The rabbit model of chronic heart failure was established by ligating the ascending aortic root. Then electrical stimulations during the absolute refractory period were delivered lasting 6 h everyday for 4 weeks in rabbits of HF+ CCM group. The QTc and ventricular effective refrective period (VERP) were recorded. The protein and mRNA levels of Kv1.4, Kv4.3 and connexin 43 (Cx43) were determined by Western blot and RT-qPCR. RESULTS: Compared with sham group, QTc were significantly prolonged in HF rabbits at week 12 (P<0.05). CCM therapy shortened QTc of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, VERP significantly increased in HF group and HF+ CCM group, while CCM therapy shortened VERP of rabbits with heart failure at week 16 (P<0.05). Compared with sham group, the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 were decreased in HF group and HF+ CCM group (P<0.05). However, CCM therapy restored the mRNA and protein levels of Kv1.4, Kv4.3 and Cx43 of rabbits with heart failure (P<0.05). CONCLUSION: CCM suppresses ventricular electrical remodeling in heart failure and the underlying mechanism may be associated with increasing Kv1.4, Kv4.3 and Cx43 expression.     

文心兰新品种‘海文吉祥1号’

文心兰新品种‘海文吉祥1号’是由文心兰‘柠檬绿’（Honey Angle）组培苗芽变株选育而来。花梗直立坚挺，花瓣和萼瓣淡黄色，唇瓣柱头处呈黄色，向四周边缘逐渐变浅成乳白色。为切花型品种，观赏价值高，应用前景广。     

70份国外小麦品种(系)的苗期和成株期抗叶锈病鉴定

小麦叶锈病是小麦生产中的重要病害之一,培育持久抗病品种是最经济、有效和环保的方法。本研究用19个不同毒力的叶锈菌小种苗期接种70份国外引进小麦品种(系)及36个已知抗叶锈病基因的载体品种进行抗性鉴定,同时在2016—2017年度分别于河北保定和河南周口对70份国外引进品种进行田间抗叶锈性鉴定。为进一步检测材料中所携带的苗期和成株抗叶锈病基因,利用12个与已知基因紧密连锁的分子标记进行检测,综合基因推导、系谱分析和分子标记检测的结果,在33份材料中鉴定出15个抗叶锈病基因,包括Lr1、Lr2a、Lr26、Lr3ka、Lr11、Lr17、Lr30、Lr10、Lr14a、Lr2b、Lr13、Lr15、Lr21、Lr44和Lr45,田间鉴定筛选出39份品种表现慢锈性。苗期和田间表现表明,国外品种中含有丰富的对我国叶锈菌小种有效的苗期和成株期抗叶锈病基因,可作为小麦抗叶锈病抗源在抗病育种中加以利用。     

宽幅机械直播对黏土地稻茬小麦出苗质量与产量的影响

苏北黏土地区光温资源不足,为抢稻茬小麦积温、提高播种出苗质量、控本增效,开展了宽幅机械直播对小麦生长发育与产量的影响试验.结果表明:宽幅机械直播处理的浅播(2 cm以内播种深度)比例、出苗率、3叶期单株分蘖和基本苗均远高于常规复式播和履带播,宽幅机械直播处理的稻茬小麦产量(8731.5 kg/hm2)分别较常规复式播和履带播高216.0、892.5 kg/hm2,因此宽幅机械直播更利于提高稻茬小麦播种和出苗质量,并能通过降低播种量获得适宜基本苗,改善群体结构,从而改善产量结构,提高稻茬小麦产量.相对于常规复式播和履带播,宽幅机械直播播幅分别高2.2倍、3.6倍,作业成本分别降低195、270元/hm2.因此,采用宽幅机械直播能提高作业效率,达到稻茬麦抢时早播的目的,并能进一步降低机械作业费,实现控本、增产、提质、增效的目标.     

海洋芽孢杆菌N11-8产蛋白酶的发酵条件优化

本研究采用响应面法(RSM)对南极海洋芽孢杆菌(Bacillus sp.)N11-8液体发酵产蛋白酶PBN11-8的发酵条件进行快速优化。通过单因素实验初步确定南极海洋芽孢杆菌N11-8产蛋白酶的最佳碳源和氮源分别为可溶性淀粉和蛋白胨；并通过Plackett-Burman(PB)设计对影响其产酶相关因素进行评估，筛选出具有显著效应的3个因素：温度、氮源和碳源；以最陡爬坡实验逼近至上述因子最大响应区域，进而采用RSM法对其最佳水平范围进行研究，确定最优发酵条件为：可溶性淀粉3 g/L，蛋白胨13.1 g/L，酵母浸粉2.9 g/L，NaCl 5 g/L，KH2PO4 1 g/L，FeCl3·6H2O 2 mmol/L，初始pH值为7.0，温度为34.0℃，转速为200 r/min，装液量为50 ml/250 ml，接种量为4%，培养时间为60 h。最终优化后的酶活达到90.5 U/ml，比初始酶活提高了23.6%。     

多环芳烃在茶树鲜叶及绿茶加工过程中残留水平研究

利用气相色谱-串联质谱联用仪监测了茶树鲜叶及其绿茶加工中多环芳烃(PAHs)的残留水平。结果表明,不同地区茶树一芽二叶样品PAHs含量差异明显,产地环境PAHs污染程度对茶鲜叶PAHs含量影响较大。茶芽、嫩叶、老叶PAHs含量分别在40.5~52.8μg·kg~(-1)、50.0~67.4μg·kg~(-1)和91.5~97.6μg·kg~(-1)之间,PAHs含量大小顺序为老叶嫩叶芽。汽车尾气对交通公路旁茶树芽和嫩叶PAHs含量影响较大,且对50 m范围内茶树鲜叶影响更明显。电加热干燥模式下,水分散失和PAHs挥发是影响绿茶加工过程中PAHs含量的两个关键因子。加工环节过后,茶叶PAHs含量由61.0μg·kg~(-1)上升到166.1μg·kg~(-1)。摊放和干燥过程中PAHs大量挥发,造成茶叶干重中PAHs残留量由292.0μg·kg~(-1)降低到171.9μg·kg~(-1)。     

四川石渠县牦牛源蜱感染巴尔通体的分子流行病学调查

为了解四川省石渠县牦牛体表寄生蜱的种类及其巴尔通体的感染情况。采集牦牛体表的蜱,经形态学初步鉴定后,提取蜱总DNA,PCR扩增蜱细胞色素氧化酶Ⅰ(COⅠ)基因和巴尔通体gltA基因,对阳性产物测序、比对,并构建系统进化树,从而确定蜱及其携带巴尔通体的种类。结果表明:在石渠县4个乡共采集到蜱818只,其中西藏革蜱占78.97%(646/818)、青海血蜱占21.03%(172/818);蜱巴尔通体的总感染率为30.07%,其中阿日扎乡、麻甲乡、德荣玛乡、长须干玛乡蜱巴尔通体的感染率分别为4.76%、76.79%、12.50%、17.95%,麻甲乡西藏革蜱巴尔通体感染率显著高于其他地点(P<0.01),麻甲乡青海血蜱巴尔通体感染率(79.07%)高于西藏革蜱(69.23%),但无显著差异(P>0.05)。经比对分析,总共得到3条序列(uncultured Bartonella sp. shiqu 1,uncultured Bartonella sp. shiqu 2和uncultured Bartonella sp. shiqu 3)。遗传进化分析显示,uncultured Bartonella sp. shiqu 1和uncultured Bartonella sp. shiqu 2与未定种的Bartonella spp. RF124HAIN (FJ464240)亲缘关系最近;uncultured Bartonella sp. Shiqu 3与对人有致病性的Bartonella melophagi亲缘关系最近。综上,石渠县存在西藏革蜱和青海血蜱,蜱巴尔通体感染率较高,并且具有感染人的风险。