GPKOW is essential for pre-mRNA splicing in?vitro and suppresses splicing defect caused by dominant-negative DHX16 mutation in?vivo

Human GPKOW [G-patch (glycine-rich) domain and KOW (Kyrpides, Ouzounis and Woese) domain] protein contains a G-patch domain and two KOW domains, and is a homologue of Arabidopsis MOS2 and Saccharomyces Spp2 protein. GPKOW is found in the human spliceosome, but its role in pre-mRNA splicing remains to be elucidated. In this report, we showed that GPKOW interacted directly with the DHX16/hPRP2 and with RNA. Immuno-depletion of GPKOW from HeLa nuclear extracts resulted in an inactive spliceosome that still bound DHX16. Adding back recombinant GPKOW restored splicing to the depleted extract. In vivo, overexpression of GPKOW partially suppressed the splicing defect observed in dominant-negative DHX16 mutant expressing cells. Mutations at the G-patch domain greatly diminished the GPKOW–DHX16 interaction; however, the mutant was active in splicing and was able to suppress splicing defect. Mutations at the KOW1 domain slightly altered the GPKOW–RNA interaction, but the mutant was less functional in vitro and in vivo. Our results indicated that GPKOW can functionally impact DHX16 but that interaction between the proteins is not required for this activity.     

Ramet Population Structure of Fargesia nitida （Mitford） Keng f. et Yi in Different Successional Stands of the Subalpine Coniferous Forest in Wolong Nature Reserve

Forest structure and succession in Wolong Nature Reserve is influenced by the understory dwarf bamboo population. However, less is known about how the forest succession affects the dwarf bamboo population. To examine the bamboo ramet population growth of Fargesla nitida （Mltford） Keng f. et Yi and to determine how ramet population structure varies along the succession of coniferous forest, we sampled ramet populations of F. nitida from the following three successional stages： （i） a deciduous broad-leaved （BL） stand; （ii） a mixed broad-leaved coniferous （MI） stand; and （ill） a coniferous （CF） stand. We investigated the population structure, biomass allocation, and morphological characteristics of the bamboo ramet among the three stand types. Clonal ramets, constituting the bamboo population, tended to become short and small with succession. The ramet changed towards having a greater mass investment in leaves, branches and underground roots and rhizomes rather than in the culm. With respect to leaf traits, individual leaf mass and area in the BL stand were markedly bigger than those In both the MI and CF stands, except for no significant difference in specific leaf area. The age distribution showed that the bamboo population approached an older age with succession. The results demonstrate that the ramet population structure of F. nitida is unstable and its growth performance is inhibited by succession.     

Effects of soybean agglutinin on body composition and organ weights in rats

An experiment was conducted to assess the effect of soybean agglutinin dosage level on growth, body composition, plasma lipids, glucose, urea nitrogen content and aminotransferase activities in rats. Male and female rats (n=60) weaned at 19 d were given a dose of 0, 3.5, 7.0, 10.5, or 14.0 mg soybean agglutinin by gastric infusion once daily for 10 days. With increasing doses of soybean agglutinin, body weight, lipid content of carcass, spleen and kidneys relative dry weights decreased, while small intestine and pancreatic weight, the contents of urea nitrogen and triglyceride, and the activities of aspartate aminotransferase linearly increased in plasma. Though soybean agglutinin decreased plasma insulin content, changes in plasma glucose content due to soybean agglutinin were not detected. It is suggested that dietary soybean agglutinin may affect the secretion of other hormones besides insulin, which modulate blood glucose reserves. In conclusion, consumption of soybean agglutinin resulted in a depletion of lipid and an overgrowth of small intestine and pancreas in rats. Meanwhile, poor growth of spleen and kidneys was observed in the soybean agglutinin-fed rats.     

基于森林碳库动态评估神农架国家级自然保护区的保护成效

保护区是维持生物多样性和生态系统功能的最有效方式, 但其保护成效有待提升, 土地利用变化是重要影响因素之一。本研究以神农架国家级自然保护区为对象, 基于神农架地区近20年的调查研究和数据积累, 通过异速生长模型、生物量方程、抽样加权等方法, 对比分析了土地利用方式转变格局下神农架国家级自然保护区森林生态系统地上、地下、凋落物、粗木质残体、土壤有机碳5个碳库动态, 分析论证了20年间(1990-2010)神农架保护区对森林生态系统碳库的保护成效。研究发现, 林地占神农架保护区总面积的92.76%, 其中针叶林(51.85%)、落叶阔叶林(35.11%)及常绿阔叶林(4.47%)3种森林类型合计占林地面积的98.56%。20年间神农架保护区林地面积增加了0.11%, 灌木林地和耕地面积分别减少了8.85%和6.06%。神农架保护区2010年碳储量为24.24 Tg C (22.57-26.62 Tg C), 土壤有机碳和地上碳合计占全部碳储量的90.68%。常绿阔叶林、落叶阔叶林和针叶林3种森林类型碳储量占神农架保护区碳储量的95%。20年间神农架保护区5个碳库碳储量均有所增加, 共固碳25.04 kt C (21.83-29.57 kt C), 固碳率为1.21 kt C/年(1.09-1.48 kt C/年), 其中地上生物量碳库和土壤有机碳库分别增加14.50 kt C (11.81-18.31 kt C)和6.84 kt C。保护区内总碳库碳密度高于保护区外22.37 t C/ha。研究结果表明, 神农架国家级自然保护区在保护森林固碳能力方面取得了一定的成效。     

Effects of Rain‐shelter Cultivation on the Temporal Dynamics of Grape Downy Mildew Epidemics

Grape downy mildew (GDM), which is caused by Plasmopara viticola (Berk et Curt.) Burl. & de Toni, is the most destructive grapevine disease in the world. In this study, we chose three cultivars that differ in their resistance to GDM and compared the effects of rain‐shelter cultivation and open‐field cultivation methods on GDM epidemics (2012–2015). The temporal dynamics of GDM were examined over a 4‐year period the results indicated that the disease index fit an S‐shaped curve, and further analysis revealed that a logistic model best fit the disease development and derived epidemic periods. Rain‐shelter cultivation significantly delayed the epidemic onset by 30 days, reduced the epidemic phase by 4 days, and decreased the final disease index by 50% as compared to open‐field cultivation. The logistic and decline phases were shortened significantly by 7 and 21 days under rain‐shelter conditions, respectively. Moreover, the rain‐shelter cultivation technique effectively decreased the highest apparent infection rate and standard area under the disease progression curve values associated with reduced disease severity. The above results demonstrate that rain‐shelter cultivation significantly affects temporal dynamics parameters of GDM. Meteorological factors had significant effects on the GDM epidemic in that the apparent infection rate was significantly positively correlated with mean temperature, relative humidity, rainfall, and leaf wetness duration before the first week of the experiment.     

Bivalent SIRT1 inhibitors

In the current study, bivalent compounds 1–17 constructed by covalently linking the ?-amino group of lysine in a tripeptidic scaffold to a functionality via a linker were prepared and examined for their inhibitory potencies against SIRT1, a prototypical member of the β-nicotinamide adenine dinucleotide (β-NAD⁺)-dependent sirtuin family of protein N^ε-acyl-lysine deacylases. A few of them were found to be stronger SIRT1 inhibitors than the N^?-acetyl-lysine-containing monovalent counterparts 18 and 19. As exemplified with compounds 6 and 18, a bivalent SIRT1 inhibitor could exhibit a greater degree of inhibitory selectivity among SIRT1/2/3 than the corresponding monovalent counterpart. This study has laid a foundation for the future development of superior bivalent inhibitors against the (patho)physiologically and therapeutically important sirtuin family of deacylase enzymes.     

Ginkgolide B Suppresses Methamphetamine-Induced Microglial Activation Through TLR4-NF-κB Signaling Pathway in BV2 Cells

Accumulating evidence suggests that microglial cells have altered morphology and proliferation in different brain regions of methamphetamine (Meth) abusers and Meth-abusing animal models. However, the possible mechanisms underlying Meth-induced microglial activation remain poorly understood. Meanwhile, Toll-like receptor4 (TLR4) is closely associated with inflammation. Therefore the aim of the present study was to assess whether Meth treatment affects TLR4 expression; in addition, we evaluated the effects of ginkgolide B (GB), a diterpene lactone extracted from Ginkgo biloba, on Meth-mediated inflammation. BV2 cells were treated with Meth. Interestingly, Meth treatment significantly increased TLR4 expression, activated the NF-κB signaling pathway, and promoted TNF-α, IL-6 and IL-1β excretion. These effects, however, were partially attenuated by GB pre-treatment. To further confirm the role of TLR4 in Meth-mediated inflammation, the siRNA technology was applied to knock down TLR4, which resulted in hampered Meth-mediated inflammatory responses, confirming the important role of TLR4 in this process. Taken together, our findings suggested that Meth exposure results in BV2 cell activation, in association with TLR4 upregulation. GB could attenuate Meth-induced inflammation, at least partially through TLR4-NF-κB signaling pathway, therefore, targeting TLR4 may constitute a potential intervention strategy for Meth mediated neuroinflammation.     

LOC100996425 acts as a promoter in prostate cancer by mediating hepatocyte nuclear factor 4A and the AMPK/mTOR pathway

The involvement of long non-coding RNAs (lncRNAs), differentially expressed genes and signals in prostate cancer (PCa) continues to be a subject of investigation. This study determined effects of LOC100996425 on human PCa by targeting hepatocyte nuclear factor 4A (HNF4A) via the AMPK/mTOR pathway. PCa and adjacent normal tissues were obtained to characterize expression pattern of LOC100996425, HNF4A and the AMPK/mTOR pathway-related genes. Then, the target gene of LOC100996425 was determined with lncRNA target prediction website and further verification was obtained through luciferase assay and ribonucleoprotein immunoprecipitation. After that, PCa cells were introduced with LOC100996425, HNF4A, siLOC100996425 or siHNF4A to explore the specific significance of LOC100996425 and HNF4A in PCa. The mechanism associated with AMPK/mTOR pathway was investigated using AMPK inhibitor or activator. LOC100996425 was up-regulated, while HNF4A was down-regulated in the PCa tissues. HNF4A was a target gene of LOC100996425. PCa cells transfected with either siLOC100996425 or HNF4A displayed reduced rates of PCa cell proliferation and migration while elevating cell apoptosis. HNF4A overexpression reversed the promotive effect of LOC100996425 overexpression on PCa. The activation of AMPK pathway involved in the cancer progression mediated by LOC100996425. Down-regulation of LOC100996425 retards progression of PCa through HNF4A-mediated AMPK/mTOR pathway.