Inhibition of mitochondrial complex I improves glucose metabolism independently of AMPK activation

Accumulating evidences showed metformin and berberine, well‐known glucose‐lowering agents, were able to inhibit mitochondrial electron transport chain at complex I. In this study, we aimed to explore the antihyperglycaemic effect of complex I inhibition. Rotenone, amobarbital and gene silence of NDUFA13 were used to inhibit complex I. Intraperitoneal glucose tolerance test and insulin tolerance test were performed in db/db mice. Lactate release and glucose consumption were measured to investigate glucose metabolism in HepG2 hepatocytes and C2C12 myotubes. Glucose output was measured in primary hepatocytes. Compound C and adenoviruses expressing dominant negative AMP‐activated protein kinase (AMPK) α1/2 were exploited to inactivate AMPK pathway. Cellular NAD⁺/NADH ratio was assayed to evaluate energy transforming and redox state. Rotenone ameliorated hyperglycaemia and insulin resistance in db/db mice. It induced glucose consumption and glycolysis and reduced hepatic glucose output. Rotenone also activated AMPK. Furthermore, it remained effective with AMPK inactivation. The enhanced glycolysis and repressed gluconeogenesis correlated with a reduction in cellular NAD⁺/NADH ratio, which resulted from complex I suppression. Amobarbital, another representative complex I inhibitor, stimulated glucose consumption and decreased hepatic glucose output in vitro, too. Similar changes were observed while expression of NDUFA13, a subunit of complex I, was knocked down with gene silencing. These findings reveal mitochondrial complex I emerges as a key drug target for diabetes treatment. Inhibition of complex I improves glucose homoeostasis via non‐AMPK pathway, which may relate to the suppression of the cellular NAD⁺/NADH ratio.     

薄层层析-比色法测定降糖安胶囊中胡芦巴皂苷B的含量

建立薄层层析-比色法测定降糖安胶囊中胡芦巴皂苷B含量的方法。采用硅胶H薄层板,氯仿：甲醇：醋酸：水(25：12：2：2)为展开剂,在碘蒸气中定位,用高氯酸显色,325nm波长处检测,点样量在35ug～385ug范围内呈现良好的线性关系,其回归方程为A=285．6C-1．313,相关系数r=0．9991,平均回收率为96．23％,RSD=1．75％。本法准确,适用于该药的质量控制。     

Complete genome sequence of a bovine viral diarrhea virus 2 from commercial fetal bovine serum

We isolated a bovine viral diarrhea virus (BVDV) from commercial fetal bovine serum and designated it HLJ-10. The complete genome is 12,284 nucleotides (nt); the open reading frame is 11,694 nt, coding 3,898 amino acids. Phylogenetic analysis indicated that this strain belongs to BVDV group 2.     

巨膜长蝽的形态特征和生物学特性

【目的】近年来巨膜长蝽Jakowleffia setulosa(Jakovlev)由以往稳定种群的荒漠昆虫上升为暴发性发生并迁移至农区危害的农业害虫。由于缺乏对巨膜长蝽基础生物学的相关研究,对其开展监测预警和农业防治存在困难。开展巨膜长蝽个体生物学研究,填补研究空白对于有效监测预报和防控提供可靠的依据,同时能为下一步分析巨膜长蝽成灾规律提供基础数据。【方法】本文通过室内观察和野外调查相结合,系统阐明该种形态特征、生活史、习性和行为等生物学特性。【结果】巨膜长蝽在宁夏中部干旱带一年发生2代,5月中旬和10月中下旬是两个发生高峰期,6月中旬至8月中旬以成虫进入滞育状态,11月下旬以成虫越冬;雌成虫的平均寿命为(32.14±2.34)d,雄成虫的平均寿命为(28.00±3.13)d,雌雄性比为1︰1.9,有多次交尾多次产卵的习性,每头雌虫抱卵量10粒左右,平均产卵量10~15粒左右;食性杂,群居危害,喜食白茎盐生草(Halogeton arachnoideus)等沙生草本植物的种子。【结论】该虫具有以成虫形态越冬和滞育、迁移性强等生物学特性。在生态环境发生较大变动后,能够经历逆境后迅速恢复种群并迁移危害。宁夏中南部地区种植结构调整,极大改变了该地区的荒漠生态环境,促使巨膜长蝽在经过夏季高温滞育恢复种群后无法获得足够野生寄主的情况下,大规模迁入农田系统危害。     

EGF receptor clustering is induced by a 0.4 mT power frequency magnetic field and blocked by the EGF receptor tyrosine kinase inhibitor PD153035

Atomic force microscopy (AFM), transmission electron microscopy (TEM), and confocal laser scanning microscopy were used to investigate the effects of a 50 Hz 0.4 mT magnetic field (MF) on the clustering of purified epidermal growth factor receptors (EGFRs) and EGFRs in Chinese hamster lung (CHL) cell membrane. The results demonstrate that exposing purified EGFRs to the MF for 30 min induces receptor clustering. The peak height of apparent clusters increased from 1.42 +/- 0.18 (sham-exposed) to 3.08 +/- 0.38 nm (exposed) while the mean half-width increased from 21.7 +/- 2.2 to 33.0 +/- 4.0 nm. A similar effect was also observed by TEM. Treatment of purified EGFR with PD153035 (PD), an EGFR-specific tyrosine kinase (TK) inhibitor, inhibited the MF-induced EGFR clustering of the purified proteins, an effect also observed for the receptors in cell membrane in the absence of EGF. These results strongly suggest that the 50 Hz 0.4 mT MF interferes with the EGFR signaling pathway, most likely by interacting with the cytoplasmic TK domain.     

听神经元的频率调谐

频率作为声音的一个重要参数,在听敏感神经元对声音进行分析和编码过程中扮演重要角色。一般用频率调谐曲线来表示听敏感神经元的频率调谐特性,并用Qn(10,30,50)值表达频率调谐曲线的尖锐程度,Qn值越大,频率调谐曲线也越尖锐,神经元的频率调谐能力越好,对频率的分辨能力越高。从听觉外周到中枢,听敏感神经元的频率调谐逐级锐化,而这种锐化主要是由听中枢的多种抑制性神经递质的作用而产生的,其中起主要作用的是GABA能和甘氨酸能神经递质。此外,离皮层调控,双侧下丘间的联合投射以及弱噪声前掩蔽等因素也会影响听敏感神经元的频率调谐特性。     

克鲁斯假丝酵母及其近似种的脉冲电泳核型分析

用钳位均匀电场脉冲电泳(CHEF)系统分析了克鲁斯假丝酵母(Candida krusei),郎比可假丝酵母(C. lambica)和粗状假丝酵母(C. valiad)的模式菌株的电泳核型,发现这三种表型相似的假丝酵母却具有互不相同的染色体DNA分子带型,为其分类学研究提供了可靠的鉴别依据。在常规分类学研究的基础上,测定了AS 2.75(原定种名为(C. incospicua),AS2.1182(原定种名为 C. lambica)和AS 2.1772(未定种)等三株假丝酵母的G+C含量和脉冲电泳核型。通过对已报道的C. inconspicu的G+C含量及上述三种假丝酵母模式菌株的脉冲电泳核型的比较分析证明,AS 2.75和AS 2.1772为粗状假丝酵母(C. valida),AS 2.1182为克鲁斯假丝酵母(C. krusei)。     

声波刺激对猕猴桃愈伤组织ATP含量的影响

采用单因子实验设计,分别先固定作为交变应力的声波的频率或强度这两个参数中的一个,而改变另一个指标的值,用声波刺激木本植物中华猕猴桃(Actinidiachinensis)茎段的愈伤组织,并测定对比声波处理前后其ATP含量及变化情况。实验结果表明,声波对猕猴桃愈伤组织ATP的含量有着比较明显的增强或抑制的双重效应,适度的声场刺激将有利于提高植物的能量代谢水平,其中,最适的声波频率为1000Hz,最适声强为100dB左右 。     

切应力对内皮细胞膜微粘度的影响

目的：研究切应力对内皮细胞（EC）膜微粘度的影响。材料和方法：将EC置于脉动循环装置中,分别施加15dyne/cm^2,50dyne/cm^2,30Odyne/cm^2切应力,作用Oh,1h,2h,4h,6h,10h后,利用带偏振器的荧光分光光度计测量膜微粘度,结果：切应力使膜微粘度增加,且切应力越高,膜微粘度增加幅度越大。切应力作用4h,EC膜微粘度升至最高,4h-10h,膜微粘度开始缓慢恢复,但仍比静态对照显著升高,结论：在切应力作用下,EC膜微粘度增加,切应力是AS的致病因素,动脉狭窄处和大中动脉分叉处是AS好发的危险部位,也是防治的重点。     

The role of GSK3beta in the development of the central nervous system

Glycogen synthase kinase 3β (GSK3β) is a multifunctional serine/threonine kinase.It is particularly abundant in the developing central nervous system (CNS).Since GSK3β has diverse substrates ranging fr...