Blockade of mGluR5 reverses abnormal firing of subthalamic nucleus neurons in 6-hydroxydopamine partially lesioned rats

Activation of metabotropic glutamate receptor 5 (mGluRs) in the subthalamic nucleus (STN) results in burst-firing activity of STN neurons, which is similar to that observed in Parkinson's disease (PD). We examined the effects of chronic and systemic treatment with 2-methyl-6-(phenylethynyl)-pyridine (MPEP), a selective mGluR5 antagonist, in firing activity of STN neurons in partially lesioned rats by 6-hydroxydopamine (6-OHDA). In 6-OHDA-lesioned rats treated with vehicle, injection of 6-OHDA (4 microg) into the medial forebrain bundle produced a partial lesion causing 36% loss of tyrosine hydroxylase-immunoreactive (TH-ir) neurons in the substantia nigra pars compacta (SNpc). The 6-OHDA lesion in vehicle-treated rats showed an increasing firing rate and a more irregular firing pattern of STN neurons. Whereas chronic, systemic treatment of MPEP (3 mg/kg/day, 14 days) produced neuroprotecive effects on the TH-ir neurons and normalized the hyperactive firing activity of STN neurons in 6-OHDA partially lesioned rats. These data demonstrate that partial lesion of the nigrostriatal pathway increases firing activity of STN neurons in the rat, and chronic, systemic MPEP treatment has the neuroprotective effect and reverses the abnormal firing activity of STN neurons, suggesting that MPEP has an important implication for the treatment of PD.     

Increased demand for NAD+ relative to ATP drives aerobic glycolysis

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The cell cycle related apoptotic susceptibility to arsenic trioxide is associated with the level of reactive oxygen species

Double staining flow cytometry was performed using 7-amino actinomycin D and 6-carboxy-2‘,7‘-dichlorodihydrofluorescein diacetate, to detect the level fluctuation of reactive oxygen species (ROS) during the cell cycle of normal NB4 cells. Our results showed that NB4 cells possessed higher level of ROS in G2/M phase than in G1 and S phases. Double staining flow cytometry, with TdT mediated dUTP nick end labeling (Tunel) and propidium iodide(PI), indicated that As2O3 (2μM) could induce apoptosis in NB4 cells prevailingly from G2/M phase, and this efficacy was enhanced upon co-administration of 2, 3-dimethoxy-1, 4-naphthoquinone (DMNQ) (2.5μM) which could produce the endogenous ROS. These results suggested that different ROS level in different cell cycle phases of NB4 cells might determin the selective induction of G2/M apoptosis and the cells‘ susceptibility to apoptosis by As2O3.     

Polymorphic Microsatellite Markers for Solen grandis and Their Cross-Species Amplification in Three Other Species

The grand jackknife clam Solen grandis is a commercially important mollusk species, but has been suffering from severe population decline due to over-exploitation and habitat destruction in China. To promote a conservation program for this species, it is necessary to evaluate its genetic diversity and population genetics. In this study, 10 novel polymorphic microsatellite makers were developed and characterized from the S. grandis through high throughput sequencing. The number of alleles at each locus ranged from 10 to 34 with an average of 20.8 alleles per locus. The observed and expected heterozygosities varied from 0.433 to 1.000 and from 0.696 to 0.976, with an average of 0.793 and 0.884, respectively. The polymorphism information content (PIC) value ranged from 0.633 (Sg43838) to 0.958 (Sg3754), with an average of 0.858. The cross-species amplification transferability of 10 loci to three closely related species ranged from 4.17 to 62.5%. These microsatellite loci will be useful for further investigation of population structure and conversation genetics of this species.     

谷胱甘肽的抗线粒体脂质过氧化作用

谷胱甘肽是细胞内重要的抗氧化损伤物质之一．以NADH诱导的牛心肌线粒体脂质过氧化体系为模型,研究了谷胱甘肽的抗氧化作用．结果表明,一定浓度的谷胱甘肽能够部分抑制该体系中线粒体的脂质过氧化．保护组的丙二醛含量为损伤组72．5％;线粒体的膨胀度较损伤组降低;细胞色素C氧化酶及ATP酶活力分别较损伤组提高了1．5及2．2倍．     

Studies of Technical Conditions of Somatic Embryogenesis in Cell Suspension Culture of Apium Graveolens

Using hypocotyls (5~10 mm) of Apium graveolens L. as explant, calli were induced in induction medium (MS + 1.0 mg/L 2, 4-D). The embryogenic calli were transformed to differentiation medium (MS+0. 5 mg/L kinetin+ 500 mg/L CH+500 mg/L Prolin) after several subsequent subcultures and selection by replacement of solid and liquid medium. Technical conditions such as the shake rate of the flask, the initial cell density, as well as subsequent the initial pH values during culture were under consideration. With the optimum flask shake rate of about 100~150 r/min, initial cell density of 2.0% (fresh weight) and the initial pH value of 5.5, the authors have obtained 130 normal cotyledon embryos in each mL of cultures.