摘要：
Listeria monocytogenes is a foodborne bacterial pathogen and the causative agent of an infectious disease, listeriosis. L. monocytogenes is ubiquitous in nature and has the ability to persist in food processing environments for extended periods of time by forming biofilms and resisting industrial sanitization. Human listeriosis outbreaks are commonly linked to contaminated dairy products, ready-to-eat meats, and in recent years, fresh produce such as lettuce and cantaloupes. We identified a putative Crp/Fnr family transcription factor Lmo0753 that is highly specific to human-associated genetic lineages of L. monocytogenes. Lmo0753 possesses two conserved functional domains similar to the major virulence regulator PrfA in L. monocytogenes. To determine if Lmo0753 is involved in environmental persistence-related mechanisms, we compared lmo0753 deletion mutants with respective wild type and complementation mutants of two fully sequenced L. monocytogenes genetic lineage II strains 10403S and EGDe for the relative ability of growth under different nutrient availability and temperatures, soil survival, biofilm productivity and attachment to select fresh produce surfaces including romaine lettuce leaves and cantaloupe rinds. Our results collectively suggested that Lmo0753 plays an important role in L. monocytogenes biofilm production and attachment to fresh produce, which may contribute to the environmental persistence and recent emergence of this pathogen in human listeriosis outbreaks linked to fresh produce.
摘要：
We previously demonstrated that the effects of diethylhexyl phthalate (DEHP) alter reproduction function on male mice. Immature male mice were treated daily with DEHP from postnatal day 7-21, 7-35, 7-49, in a dose-dependent manner. As results, both the quality and quantity of spermatozoa were decreased in 60-day-old mice. The results by RT-PCR analysis indicated that DDx3Y, Usp9Y, RBM, E1F1AY, EGF, FSHR and EGFR genes were down-regulated, and LHR, Cyp17a1 and Cyp19a1 were down-regulated in response to DEHP. These genes were selected based on their markedly increased or decreased expression levels. However, DEHP had no effect on the meiotic process and recombination levels in male mouse germ cells. Treatment with DEHP induced histopathological changes in the testes. Taken together, these results provide a new insight into the molecular mechanisms underlying the detrimental impacts of DEHP in humans and wildlife.
摘要：
Eutrophication has occurred frequently in various lakes and reservoirs, and the metabolic excretion produced during the algae growth causes serious water pollution and threatens ecological security. Biological control approaches such as screening bacteria with the capability to degrade cyanobacteria are an environment-friendly way. An isolated antialgal strain Streptomyces sp. KY-34, was applied to degrade the cyanobacterium Microcystis aeruginosa, and the possible biodegradation mechanism was investigated. The results showed that the fermentation liquor of Streptomyces sp. KY-34 could inhibit the growth of M. aeruginosa by restrained the synthesis of chlorophyll and photosynthetic pigments, and decreasing the contents of cellular protein and non-protein, accordingly led to the increase of malondialdehyde content, and the activities of superoxide dismutase, catalase and peroxidase in algae cells. In addition, the variation of the cellular ultrastructure indicated a serious change in algal physiology. It's revealed that the biodegradation mechanism of M. aeruginosa should primarily be that Streptomyces sp. KY-34 caused the damage of algae cell membrane and led to the increases of antioxidant enzymes, and then the growth of M. aeruginosawas inhibited. (C) 2013 Elsevier B.V. All rights reserved.
摘要：
Candida antarctica lipase B (CALB) is one of the most widely used and studied enzymes in the world. In order to achieve the high-level expression of CALB in Pichia, we optimized the codons of CALB gene and alpha-factor by using a de novo design and synthesis strategy. Through comparative analysis of a series of recombinants with different expression components, we found that the methanol-inducible expression recombinant carrying the codon-optimized alpha-factor and mature CALB gene (pPIC9K alpha M-CalBM) has the highest lipase production capacity. After fermentation parameters optimization, the lipase activity and protein content of the recombinant pPIC9K alpha M-CalBM reached 6,100 U/mL and 3.0 g/L, respectively, in a 5-L fermentor. We believe this strategy could be of special interest due to its capacity to improve the expression level of target gene, and the Pichia transformants carrying the codon-optimized gene had great potential for the industrial-scale production of CALB lipase.
摘要：
Lipopolysaccharide (LPS) is a known activator of mononuclear phagocytes. LPS activates the pro-inflammatory gene expression and induces the release of mediators/cytokines by TLR4-NF-kappa B signaling pathway. The purpose of this study was to investigate the effects of acetaminophen (AAP) and N-acetylcysteine (NAC), individually as well as in combination on LPS-induced cytokines production and NF-kappa B activation in piglets. AAP (0.125-1.0 mM) and NAC (0.0625-1.0 mM) down-regulate the expression of cytokines and inhibit NF-kappa B p65 protein transfer from the cytoplasm to the nucleus in vitro. NAC enhances the inhibition action of AAP on cytokines expression in vitro. IL-6 in piglet plasma of the AAP group (mixed feed concentration of 600 mg/kg) was significantly reduced (P<0.05) at3 h after LPS-challenge as compared with the LPS control group. IL-10 also significantly reduced (P<0.05) at 24 h after LPS injection. The levels of inflammatory cytokines (TNF-alpha, IL-1p, IL-6, and IL10) in piglet plasma of the NAC group (mixed feeding concentration of 1200 mg/kg) were significantly lower at 3 h after LPS stimulation (P<0.05). IL-10 was significantly decreased in the NAC group at 24 h after LPS stimulation (P<0.05). AAP or NAC treated alone could reduce the NF-kappa B p65 concentration ratio. The levels of cytokines (TNF-alpha, IL-1 p, IL-6, and IL-10) in the group with piglet plasma of AAP (mixed feed concentration of 600 mg/kg) plus NAC (mixed feeding concentration of 1200 mg/kg) group were significantly lower (P<0.05) at 3 h after LPS activation. The level of IL-10 in the group with AAP plus NAC was significantly lower (P<0.05) at 24h after LPS stimulation, while the rest of the inflammatory cytokines were returned to the original levels. The NF-kappa B p65 concentration ratio had significantly reduced (P<0.05) when AAP and NAC were used in combination. In summary, NAC could enhance the anti-inflammatory effects of AAP both in vitro and in vivo. (C) 2013 Elsevier B.V. All rights reserved.
摘要：
A series of studies have recently demonstrated that the release of
interleukin 1β induced by monosodium urate crystals is central to the
experimental gouty arthritis. Elaeagnus pungens has been
traditionally used for the treatment of gouty arthritis in China for more
than thousands years. However, there is still little known about the active
ingredients and mechanisms of E. pungens against gouty arthritis.
Emodinol, as a major triterpene compound in E. pungens, has been
seldom reported to have an effect on gouty arthritis. Therefore, the
potential beneficial effects and mechanisms of emodinol on gouty arthritis
were investigated in this study. Results showed that it significantly
ameliorated the hyperalgesia, inflammation, and levels of multiple
proinflammatory cytokines in monosodium urate crystals-treated mice. These
findings elucidate that emodinol exhibits a prominent effect on improving
symptoms of acute gouty arthritis induced by monosodium urate crystals
through inhibiting the generation of proinflammatory cytokines.
摘要：
Alzheimer's disease (AD) is one of the most debilitating neurodegenerative nerve diseases, seriously affecting one's ability to carry out daily activities. AD is both progressive and incurable, but molecular studies have begun to shed light on the mechanisms that underlie it. Immunochemical staining showed that cell bodies of Purkinje cells in the cerebellum were significantly reduced in AD rats compared with normal rats. Heat shock protein 70 (HSP70) was found to prevent polyglutamine aggregation in Huntington's disease and spinocerebellar ataxias (SCAs) and to relieve symptoms in SCAs and Parkinson's disease. Recently, AD-related phenotypes were found to be suppressed in HSP70 transgenic rats. However, the effects of other HSPs and the mechanisms of HSP-triggered changes in AD are unknown. In this study, we found that expression levels of HSP60, -70, and -90 were downregulated in the cerebella of rats with AD. Furthermore, heat shock factor 1 (HSF1), a key transcription factor for the expression of HSP genes, was found to be greatly decreased in the cerebella of AD rats. Even more interesting, injection of lentivirus vector-HSF1 into the cerebella of AD rats significantly increased HSF1 and HSP expression levels and induced an increase in the number of Purkinje cell bodies. Our findings provide novel evidence that low expression of HSPs in AD rats is dependent on the low expression of HSF1, and increased expression of HSF1 contributes to the reversal of cerebellar Purkinje cell deficiency in AD. Therefore, increasing HSF1 expression is a potential new strategy for the treatment of AD.
摘要：
Bisphenol A (BPA), a chemical used in many consumer products, interferes with the endocrine system of mammals, including humans. The aim of the present study was to investigate the effect of BPA on spermatogenesis and semen quality. The objective of this study was to assess the effects of BPA on mouse spermatogenesis. CD1 mice were used in all experiments. Mice were treated with different doses of BPA (0, 20 and 40 mug kg(-)(1) day(-)(1) from postnatal Day (PND) 3 to PND21, PND 35 or PND49. After 5 weeks BPA treatment, oestrogen receptor alpha expression was increased in mouse testis, whereas the meiotic progression of germ cells was slowed. Thus, both the quality and quantity of spermatozoa were decreased in 7-week-old mice. However, BPA had no effect on DNA methylation of imprinted genes such as Igf2, Igf2r, Peg3 and H19, in germ cells. In addition, exposure of male mice to BPA resulted in abnormal offspring that were smaller with a low-quality pelage when they were 35 days old. In conclusion, BPA hampers spermatogenesis and the subsequent development of offspring.
摘要：
In vitro gene chemical synthesis is a powerful tool to improve the expression of gene in heterologous system. In this study, a two-step gene synthesis strategy that combines an assembly PCR and an overlap extension PCR (AOE) was developed. In this strategy, the chemically synthesized oligonucleotides were assembled into several 200-500 bp fragments with 20-25 bp overlap at each end by assembly PCR, and then an overlap extension PCR was conducted to assemble all these fragments into a full length DNA sequence. Using this method, we de novo designed and optimized the codon of Rhizopus oryzae lipase gene ROL (810 bp) and Aspergillus niger phytase gene phyA (1404 bp). Compared with the original ROL gene and phyA gene, the codon-optimized genes expressed at a significantly higher level in yeasts after methanol induction. We believe this AOE method to be of special interest as it is simple, accurate and has no limitation with respect to the size of the gene to be synthesized. Combined with de novo design, this method allows the rapid synthesis of a gene optimized for expression in the system of choice and production of sufficient biological material for molecular characterization and biotechnological application.
期刊：
Russian Journal of Genetics,2012年48(10):1029-1034 ISSN：1022-7954
通讯作者：
Xie, J. Y.
作者机构：
[Xie, J. Y.] Wuhan Polytech Univ, Sch Biol & Pharmaceut Engn, Wuhan 430023, Peoples R China.
通讯机构：
[Xie, J. Y.] W;Wuhan Polytech Univ, Sch Biol & Pharmaceut Engn, Wuhan 430023, Peoples R China.
关键词：
Freshwater Lake;Taihu Lake;Discriminant Function Analysis;Yellow Perch;Chaohu Lake
摘要：
Population structure of the important commercial fish, Coilia ectenes, was investigated in samples from three freshwater lakes in the Eastern China using a multivariate approach of morphometrics and mitochondrial DNA control region sequencing. A total of eighteen morphological distances of truss method and eight morphometric variables were taken from each fish. Multivariate analyses of the morphometric data revealed significant morphological differences among the three lake populations, especially for those samples from Taihu Lake. Discriminant functions were used to compare sites, and these permitted an 83% success rate in distinguishing fish from the three sites. However, no obviously geographical differentiation was found among those populations of C. ectenes based on the genetic data. In the AMOVA analysis, only 2.2% genetic variability came from different populations, and most of them were present within the sub-populations. Experience a recent population expansion and some movement of fish among those areas, quite possibly enough to bring about relative genetic homogeneity, but there is insufficient to prevent the three populations from differing phenotypically. The diversified environmental factors may be playing an important role in shaping morphological variations among those populations.
作者：
Tao, Weixin;Lee, Myung Hwan;Wu, Jing;Kim, Nam Hee;Kim, Jin-Cheol;...
期刊：
Applied and Environmental Microbiology,2012年78(17):6295-6301 ISSN：0099-2240
通讯作者：
Lee, Seon-Woo
作者机构：
[Chung, Eunsook; Tao, Weixin] Dong A Univ, Dept Med Biotechnol, Pusan, South Korea.;[Lee, Seon-Woo; Lee, Myung Hwan; Kim, Nam Hee; Hwang, Eul Chul] Dong A Univ, Dept Appl Biol, Pusan, South Korea.;[Wu, Jing] Wuhan Polytech Univ, Dept Biol & Pharmaceut Engn, Wuhan, Peoples R China.;[Kim, Jin-Cheol] KRICT, Chem Biotechnol Res Ctr, Taejon, South Korea.
通讯机构：
[Lee, Seon-Woo] D;Dong A Univ, Dept Appl Biol, Pusan, South Korea.
