Peroxisome proliferator-activated receptor delta is up-regulated during vascular lesion formation and promotes post-confluent cell proliferation in vascular smooth muscle cells.

Although peroxisome proliferator-activated receptor (PPAR) delta is widely expressed in many tissues, the role of PPARdelta is poorly understood. In this study, we report that PPARdelta was up-regulated in vascular smooth muscle cells (VSMC) during vascular lesion formation. By using Northern blot analysis, we demonstrated that PPARdelta was increased by 3-4-fold in VSMC treated with platelet-derived growth factor (PDGF) (20 ng/ml). In addition, PDGF-induced PPARdelta mRNA expression neither needs de novo protein synthesis nor affects the stability of PPARdelta mRNA in VSMC. Preincubation of VSMC with phosphatidylinositol 3-kinase inhibitor (LY294002, 50 micromol/liter) or infection of VSMC with an adenovirus carrying the gene for a dominant negative form of Akt abrogated PDGF-induced PPARdelta mRNA expression, suggesting that phosphatidylinositol 3-kinase/Akt signaling pathway is involved in the regulation of PDGF-induced PPARdelta mRNA expression in VSMC. To explore the role of PPARdelta in VSMC, we generated rat vascular smooth muscle cells (A7r5) stably overexpressing PPARdelta and the control green fluorescent protein. Overexpression of PPARdelta in VSMC increased post-confluent cell proliferation by increasing the cyclin A and CDK2 as well as decreasing p57(kip2). Taken together, the results suggest that PPARdelta plays an important role in the pathology of diseases associated with VSMC proliferation, such as primary atherosclerosis and restenosis.     

脑源性神经营养因子及其临床研究进展

脑源性神经营养因子 (BDNF)是继神经生长因子 (NGF)后发现的第二个神经营养因子 ,在神经系统的发育、功能维持和神经元群的成形性上起重要作用。国内外正积极开发 BDNF用于神经损伤的治疗。本文就 BDNF的结构、功能、信号传导以及临床研究等作一综述     

Identification and targeting of G-quadruplex structures in MALAT1 long non-coding RNA

RNA G-quadruplexes (rG4s) have functional roles in many cellular processes in diverse organisms. While a number of rG4 examples have been reported in coding messenger RNAs (mRNA), so far only limited works have studied rG4s in non-coding RNAs (ncRNAs), especially in long non-coding RNAs (lncRNAs) that are of emerging interest and significance in biology. Herein, we report that MALAT1 lncRNA contains conserved rG4 motifs, forming thermostable rG4 structures with parallel topology. We also show that rG4s in MALAT1 lncRNA can interact with NONO protein with high specificity and affinity in vitro and in nuclear cell lysate, and we provide cellular data to support that NONO protein recognizes MALAT1 lncRNA via rG4 motifs. Notably, we demonstrate that rG4s in MALAT1 lncRNA can be targeted by the rG4-specific small molecule, peptide, and L-aptamer, leading to the dissociation of MALAT1 rG4-NONO protein interaction. Altogether, this study uncovers new and important rG4s in MALAT1 lncRNAs, reveals their specific interactions with NONO protein, offers multiple strategies for targeting MALAT1 and its RNA–protein complex via its rG4 structure and illustrates the prevalence and significance of rG4s in ncRNAs.     

木林子国家级自然保护区苔藓植物物种与区系研究

基于野外调查、采集标本和查阅文献,对木林子国家级自然保护区苔藓植物物种及区系特点进行研究。结果显示:该保护区苔藓植物共有64科121属292种,其中,苔类28科38属88种,藓类36科83属204种。该保护区共有湖北新记录科2科、新记录属9属、新记录种73种。该保护区苔藓植物区系成分多样,有11个区系类型,以温带成分为主(占30.89%)、东亚成分次之(占18.92%)。相比清凉峰、大巴山、十万大山和佛坪4个国家级自然保护区,木林子呈现出科多种少的特点,物种分化程度更高。木林子保护区与清凉峰的苔藓植物组成相似度最高,与佛坪相似度最低。该研究结果从苔藓植物多样性的角度佐证了清江流域物种分化程度较高的观点,为丰富木林子国家级自然保护区苔藓植物和湖北省苔藓植物提供了基础资料。     

Growth monitoring and control in complex medium: a case study employing fed-batch penicillin fermentation and computer-aided on-line mass balancing

To broaden the practicality of on-line growth monitoring and control, its application in fedbatch penicillin fermentation using high corn steep liquor (CSL) concentration (53 g/L) is demonstrated. By employing a calculation method that considers the vagaries of CSL consumption, overall and instantaneous carbon-balancing equations are successfully used to calculate, on-line, the cell concentration and instantaneous specific growth rate in the penicillin production phase. As a consequence, these equations, together with a feedback control strategy, enable the computer control of glucose feed and maintenance of the preselected production-phase growth rate with error less than 0.002 h(-1).     

Synthesis of hydrolytic enzymes during production of tylosin byStreptomyces fradiae

Summary The exposure of a wild-type tylosin producing strain ofStreptomyces fradiae to mutagenic agents resulted in the isolation of several tylosin over-producing strains. Examination of three mutants, T4310, 612 and 3204 showed that improved tylosin production was associated with increased hydrolytic enzyme activity and cell growth. The wild-type strain showed lower levels of hydrolytic activity including, protease, amylase, lipase and esterase activities and attained a lower cell density than the mutants.     

农田林网环境效益监测研究

林带是农田林网的组成部分,其群体稳定,生物量高,为人们提供木材和林副产品,而且还具有改善环境的作用和功能。以往研究已充分揭示和认识了农田林网调节气候、涵养水源、防风固沙、防止水土流失、保护农田的功能和意义,而对林带树木的环境作用研究尚处于探索之中。宁夏林业建设发展较快,尤其是     

柠条Ca~(2+)-ATPase的性质及钙调素含量与抗旱性的关系

分离纯化旱生植物柠条的叶细胞质膜,测定其Ca2＋-ATPase的最适反应pH、最适反应温度、底物ATP和激活剂Ca2＋对酶活性的影响,并与中生植物小麦叶细胞质膜Ca2＋-ATPase的性质进行比较。实验表明柠条叶细胞质膜Ca2＋-ATPase的最适反应pH为7．5,最适反应温度为55℃,酶对ATP的Hill系数为0．94,符合米氏动力学类型,对Ca2＋的Hill系数为0．35,具有负协同作用。还测定了柠条和小麦叶片中及叶细胞质膜结合的钙调素含量,发现钙调素含量与植物的抗旱性成正相关。     

氨基酸厂废水对植物种子萌发和幼苗生长影响的研究

水稻、大麦、油菜等种子在不同条件下的发芽试验,表明氨基酸厂废水对植物种子萌发存在明显的抑制作用,且这种抑制作用主要表现在出芽阶段生物化学代谢最旺盛的时期,发现淀粉性种子对废水的忍耐程度要低于油脂性种子,同时进行的植物幼苗试验显示,大麦土培时废水最适宜的浓度为１：１００－１：１５０（废水原液与清水体积之比,下同）,水稻砂培为１：１００。     

A novel low-temperature resistant alkaline lipase from a soda lake fungus strain Fusarium solani N4-2 for detergent formulation

The effects of temperature, pH, and various components in a detergent on the activity and stability of a lipase produced by a soda lake fungus strain Fusarium solani N4-2 were studied in a preliminary evaluation for use in detergent formulation. The molecular mass of the lipase was 31.6 kDa by SDS-PAGE after purification using acetone fractionation and Q-sepharose ion exchange technique. In aqueous solutions, the lipase showed maximal activity at pH 9.0 in a glycine–NaOH buffer at 30 °C. At 0 °C and 10 °C, 52.3% and 82.6% of its maximum activities were detained, respectively. Among the metal ions tested, additions of Cu²⁺, Ca²⁺, Mg²⁺, Al³⁺ and Mn²⁺ ions were found to enhance the enzyme activity while Zn²⁺, Ba²⁺ and Hg²⁺ ions showed inhibitory effects. Compared with the commercial lipase Lipolase^®, the enzyme showed better stability towards selected surfactants, commercial detergents, oxidizing agents and proteases. The remarkable resistance capability of the lipase makes it a potential additive for better detergent formulation.