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：
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：
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：
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.
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.
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.
摘要：
Bisphenol A (BPA), a synthetic additive used to harden polycarbonate plastics and epoxy resin, is ubiquitous in our everyday environment. Many studies have indicated detrimental effects of BPA on the mammalian reproductive abilities. This study is aimed to test the potential effects of BPA on methylation of imprinted genes during oocyte growth and meiotic maturation in CD-1 mice. Our results demonstrated that BPA exposure resulted in hypomethylation of imprinted gene Igf2r and Peg3 during oocyte growth, and enhanced estrogen receptor (ER) expression at the levels of mRNA and protein. The relationship between ER expression and imprinted gene hypomethylation was substantiated using an ER inhibitor, ICI182780. In addition, BPA promoted the primordial to primary follicle transition, thereby speeding up the depletion of the primordial follicle pool, and suppressed the meiotic maturation of oocytes because of abnormal spindle assembling in meiosis I. In conclusion, neonatal exposure to BPA inhibits methylation of imprinted genes during oogenesis via the ER signaling pathway in CD-1 mice.
关键词：
Capsaicin;Intracellular second messenger;Nociceptors;Pain;TRPV1 receptor
摘要：
Intracellular second messengers play an important role in capsaicin- and analogous-induced sensitization and desensitization in pain. Fluorescence Ca2+ imaging, enzyme immunoassay and PKC assay kit were used to determine a novel mechanism of different Ca2+ dependency in the signal transduction of capsaicin-induced desensitization. On the average, capsaicin increased cAMP, cGMP concentration and SP release in bell-shaped concentration-dependent manner, with the maximal responses at concentrations around 1 mu M, suggesting acute desensitization of TRPV1 receptor activation. Capsaicin-induced intracellular Ca2+ concentration ([Ca2+](i)) increase depended on extracellular Ca2+ influx as an initial trigger. The Ca2+ influx by capsaicin increased PKC activation and SP release. These increases were completely abolished in Ca2+-free solution, suggesting that the modulation of capsaicin on PKC and SP are Ca2+-dependent. Interestingly, the maximal cAMP increase by TRPV1 activation was not blocked Ca2+ removal, suggesting at least in part a Ca2+-independent pathway is involved. Further study showed that cAMP increase was totally abolished by G-protein and adenylate cyclase (AC) antagonist, suggesting a G-protein-dependent pathway in cAMP increase. However, SP release was blocked by inhibiting PKC, but not G-protein or AC, suggesting a G-protein independent pathway in SP release. These results suggest that both Ca2+-dependent and independent mechanisms are involved in the regulation of capsaicin on second messengers systems, which could be a novel mechanism underlying distinct desensitization of capsaicin and might provide additional opportunities in the development of effective analgesics in pain treatment. (c) 2012 Elsevier Ireland Ltd. All rights reserved.
