microRNA-95 knockdown inhibits epithelial–mesenchymal transition and cancer stem cell phenotype in gastric cancer cells through MAPK pathway by upregulating DUSP5

This study investigated the role of microRNA-95 (miR-95) in gastric cancer (GC) and to elucidate the underlying mechanism. Initially, bioinformatic prediction was used to predict the differentially expressed genes and related miRNAs in GC. miR-95 and DUSP5 expression was altered in GC cell line (MGC803) to evaluate their respective effects on the epithelial–mesenchymal transition (EMT) process, cellular processes (cell proliferation, migration, invasion, cell cycle, and apoptosis), cancer stem cell (CSC) phenotype, as well as tumor growth ability. It was further predicted in bioinformatic prediction and verified in GC tissue and cell line experiments that miR-95 was highly expressed in GC. miR-95 negatively regulated DUSP5, which resulted in the MAPK pathway activation. Inhibited miR-95 or overexpressed DUSP5 was observed to inhibit the levels of CSC markers (CD133, CD44, ALDH1, and Lgr5), highlighting the inhibitory role in the CSC phenotype. More important, evidence was obtained demonstrating that miR-95 knockdown or DUSP5 upregulation exerted an inhibitory effect on the EMT process, cellular processes, and tumor growth. Together these results, miR-95 knockdown inhibited GC development via DUSP5-dependent MAPK pathway.     

Methyl-compounds driven benthic carbon cycling in the sulfate-reducing sediments of South China Sea

Methane is a potent greenhouse gas; methane production and consumption within seafloor sediments has generated intense interest. Anaerobic oxidation of methane (AOM) and methanogenesis (MOG) primarily occur at the depth of the sulfate–methane transition zone or underlying sediment respectively. Methanogenesis can also occur in the sulfate-reducing sediments through the utilization of non-competitive methylated compounds; however, the occurrence and importance of this process are not fully understood. Here, we combined a variety of data, including geochemical measurements, rate measurements and molecular analyses to demonstrate the presence of a cryptic methane cycle in sulfate-reducing sediments from the continental shelf of the northern South China Sea. The abundance of methanogenic substrates as well as the high MOG rates from methylated compounds indicated that methylotrophic methanogenesis was the dominant methanogenic pathway; this conclusion was further supported by the presence of the methylotrophic genus Methanococcoides. High potential rates of AOM were observed in the sediments, indicating that methane produced in situ could be oxidized simultaneously by AOM, presumably by ANME-2a/b as indicated by 16S rRNA gene analysis. A significant correlation between the relative abundance of methanogens and methanotrophs was observed over sediment depth, indicating that methylotrophic methanogenesis could potentially fuel AOM in this environment. In addition, higher potential rates of AOM than sulfate reduction rates at in situ methane conditions were observed, making alternative electron acceptors important to support AOM in sulfate-reducing sediment. AOM rates were stimulated by the addition of Fe/Mn oxides, suggesting AOM could be partially coupled to metal oxide reduction. These results suggest that methyl-compounds driven methane production drives a cryptic methane cycling and fuels AOM coupled to the reduction of sulfate and other electron acceptors.     

Allotransplantation of adult spinal cord tissues after complete transected spinal cord injury: Long-term survival and functional recovery in canines

Science China Life Sciences - Spinal cord injury (SCI), especially complete transected SCI, leads to loss of cells and extracellular matrix and functional impairments. In a previous study, we...     

Coumaroyl flavonol glycosides from the leaves of Ginkgo biloba.

Two coumaroyl flavonol glycosides, isorhamnetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], and kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, were isolated from the n-BuOH extract of Ginkgo biloba leaves. These two, together with six other flavonol glycosides, kaempferol 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside], quercetin 3-O-alpha-L-[6"'-p-coumaroyl-(beta-D)-glucopyranosyl-(1,2)-rhamnopyranoside]-7-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-glucopyranosyl-(1-2)-alpha-L-rhamnopyranoside, quercetin 3-O-beta-rutinoside, and quercetin 3-O-beta-D-glucopyranoside, showed profound antioxidant activities in DPPH and cytochrome-c reduction assays using the HL-60 cell culture system.     

Immunogens Modeling a Fusion-Intermediate Conformation of gp41 Elicit Antibodies to the Membrane Proximal External Region of the HIV Envelope Glycoprotein

The membrane proximal external region (MPER) of the gp41 subunit of the HIV-1 envelope glycoprotein (Env) contains determinants for broadly neutralizing antibodies and has remained an important focus of vaccine design. However, creating an immunogen that elicits broadly neutralizing antibodies to this region has proven difficult in part due to the relative inaccessibility of the MPER in the native conformation of Env. Here, we describe the antigenicity and immunogenicity of a panel of oligomeric gp41 immunogens designed to model a fusion-intermediate conformation of Env in order to enhance MPER exposure in a relevant conformation. The immunogens contain segments of the gp41 N- and C-heptad repeats to mimic a trapped intermediate, followed by the MPER, with variations that include different N-heptad lengths, insertion of extra epitopes, and varying C-termini. These well-characterized immunogens were evaluated in two different immunization protocols involving gp41 and gp140 proteins, gp41 and gp160 DNA primes, and different immunization schedules and adjuvants. We found that the immunogens designed to reduce extension of helical structure into the MPER elicited the highest MPER antibody binding titers, but these antibodies lacked neutralizing activity. The gp41 protein immunogens also elicited higher MPER titers than the gp140 protein immunogen. In prime-boost studies, the best MPER responses were seen in the groups that received DNA priming with gp41 vectors followed by gp41 protein boosts. Finally, although titers to the entire protein immunogen were similar in the two immunization protocols, MPER-specific titers differed, suggesting that the immunization route, schedule, dose, or adjuvant may differentially influence MPER immunogenicity. These findings inform the design of future MPER immunogens and immunization protocols.     

Metagenomic analysis for the microbial consortium of anaerobic CO oxidizers

Metagenomics analysis has been applied to identify the dominant anaerobic microbial consortium of the carbon monoxide (CO) oxidizers in anaerobic sludge. Reads from the hypervariable V6 region in the bacterial 16s rDNA were aligned and finally clustered into operational taxonomic units (OTUs). The OTUs from different stages in anaerobic CO condition were classified. Alphaproteobacteria, clostridia, betaproteobacteria and actinobacteria were the most abundant groups, while alphaproteobacteria, betaproteobacteria and actinobacteria were variable groups. CO consumption and production efficiency of the microbial consortium were studied. Semi-continuous trials showed that these anaerobic CO oxidizers formed a stable microbial community, and the CO conversion rate was at over 84%, with the highest CO consumption activity of 28.9 mmol CO/g VSS●day and methane production activity at 7.6 mmol CH₄/g VSS●day during six cycles.     

Molecular phylogenetic relationships of China Seas groupers based on cytochrome <Emphasis Type="Italic">b</Emphasis> gene fragment sequences

The classification and evolutionary relationships are important issues in the study of the groupers. Cytochrome b gene fragment of twenty-eight grouper species within six genera of subfamily Epinephelinae was amplified using PCR techniques and the sequences were analyzed to derive the phylogenetic relationships of the groupers from the China Seas. Genetic information indexes, including Kimura-2 parameter genetic distance and T _S/T _V ratios, were generated by using a variety of biology softwares. With Niphon spinosus, Pagrus major and Pagrus auriga as the designated outgroups, phylogenetic trees, which invoke additional homologous sequences of other Epinephelus fishes from GenBank, were constructed based on the neighbor-joining (NJ), maximum-parsimony (MP), maximum-likelihood (ML) and minimum-evolution (ME) methods. Several conclusions were drawn from the DNA sequences analysis: (1) genus Plectropomus, which was early diverged, is the most primitive group in the subfamily Epinephelinae; (2) genus Variola is more closely related to genus Cephalopolis than the other four genera; (3) genus Cephalopolis is a monophyletic group and more primitive than genus Epinephelus; (4) Promicrops lanceolatus and Cromileptes altivelis should be included in genus Epinephelus; (5) there exist two sister groups in genus Epinephelus.     

虎源H5N1亚型高致病性禽流感病毒人工感染家猫的病理学研究

经SPF鸡胚增殖的虎源高致病性禽流感病毒A/Tiger/Harbin/01/2002(H5N1)株,其对MDCK细胞的TCID50为10-7.36/0.05 mL,经气管接种途径人工感染家猫,对感染致死的家猫和对照组家猫心、肝、脾、肺、肾、脑等脏器进行组织病理学观察和免疫组织化学染色,同时采集咽拭子和各脏器乳剂上清液进行RT-PCR检测,对耐过家猫与对照组家猫进行HI抗体测定。结果表明:剖检感染的死亡家猫以肺脏的损害最为明显,肺叶上有大片暗红色实变灶,呈多病灶融合性肺损伤。组织学光镜观察,病毒对家猫的损害主要见于肺脏,呈融合性炎性病变,浸润的主要为单核细胞,肺泡腔内可见较多量巨噬细胞浸润及少量蛋白样浆液渗出。免疫组织化学染色发现在支气管上皮细胞、少数肺泡上皮细胞和单核细胞胞浆中可见到该病毒的抗原阳性染色颗粒。RT-PCR检测结果在咽拭子以及肺、肾、心、脑组织中均扩出与理论值一致的464bp核酸条带,耐过家猫血清H5N1亚型流感病毒HI抗体效价为1∶32。     

转基因植物环境安全评价策略

构建完善的转基因植物环境安全评价技术体系是保障转基因生物产业健康发展的重要组成部分。本文综述了转基因植物环境安全评价技术发展历程与趋势,归纳了转基因植物环境安全评价的思路与内容。转基因植物环境安全评价应分为潜在风险分析、风险假设验证、风险特征描述等3个步骤,并采用逐层评价模式;安全评价应贯穿转基因植物新品种研发与产业化全程,包括应用前预测、研发中筛选、推广前评价、推广后监测。此外,基于科学性和个案分析原则,本文对复合性状、非生物胁迫抗性等新型转基因植物环境安全评价策略进行了探讨。