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971.
Gap junction provides intercellular communications that play a critical role in invasion of metastatic cancer cells. However,
the effects of inhibiting this pathway in breast cancer cell migration have not been investigated. Here, we present data demonstrating
that functional blockade of gap junctions during the formation of monolayer decreased the levels of aligned fibers of actin
between neighboring breast cancer cells. Furthermore, gap junction inhibitors attenuated the invasion ability of highly metastatic
MDA-MB-231 cells, but had no significant effects on less invasive MCF-7 cells, which caused by shRANKL. Our work is the first
to demonstrate the inhibitory effect of gap junction channel inhibitors on the migration of highly invasive breast cancer
cells. 相似文献
972.
Wang XL Dou JT Gao JP Zhong WW Jin D Hui L Lu JM Mu YM 《Neuro endocrinology letters》2012,33(3):265-267
Tumors originating from ectopic adrenal tissue are relatively rare. In this article, we describe a case with Cushing's syndrome caused by an ectopic adrenal adenoma. A 38 year-old male patient presenting with cushingoid appearance for 2 years was diagnosed to have ACTH-independent Cushing's syndrome based on endocrinological evaluation. Mutiple radiological examinations detected bilateral adrenal atrophy. When the images were investigated in a more expanded scope, a 3.0×3.5×5.3?cm mass was detected in the anterior of left renal hilum and left renal vein. The mass was successfully resected with intraoperative endoscopy and pathological evaluation revealed an ectopic adrenal tumor. It is suggested that when the endocrinlogically confirmed adrenal neoplasm could not be well and definitely localized, the possibility of ectopic adrenal should be presumed and further radiography examinations should extend to the field where ectopic adrenal usually presents. 相似文献
973.
Chen JF Zhong WQ Wang DH 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2012,182(2):275-285
Small mammals inhabiting temperate and arctic regions exhibit annual adaptive adjustments in physiology, anatomy, and behavior.
No data on the physiology of Maximowicz’s voles (Microtus maximowiczii) are available at present. Here we examined the seasonal changes in body mass, food intake, thermogenic capacity, serum leptin
and thyroid hormone levels in wild-captured individuals from Inner Mongolian grassland, China. We further examined the effects
of photoperiod on these parameters. Energy intake, resting metabolic rate, nonshivering thermogenesis (NST), and serum tri-iodothyronine
(T3) levels increased while serum leptin and body mass decreased in the cold seasons. Serum T3 levels were positively correlated
with NST and uncoupling protein 1 (UCP1) contents in brown adipose tissue, and leptin levels were negatively correlated with
energy intake and resting metabolic rate. Furthermore, laboratory data showed these changes could be induced by short photoperiod
alone. Taken together, our results indicate that Maximowicz’s voles can increase thermogenic capacity and energy intake to
cope with cold stress. Serum leptin seems to be involved in the regulation of energy intake and changes in T3 level may be
important for the variations in NST and/or UCP1. Short photoperiod can serve as a seasonal cue for the winter acclimatization
of energy balance in free-living Maximowicz’s voles. 相似文献
974.
Thermophilic enzymes are in high demand for various applications due to their prolonged lifetimes and high reaction rates
at elevated temperatures. In this work, an open reading frame TM0295, which encodes a putative transaldolase (TAL) from a
hyper-thermophilic microorganism, Thermotoga maritima, was cloned and expressed in Escherichia coli. The enzyme activity of transaldolase at high temperatures (e.g., at 80 °C) was reported here for the first time. The recombinant
T. maritima transaldolase was extremely thermostable, with a half-life time of 198 and 13.0 h at 60 °C and 80 °C, respectively. The estimated
total turn-over number was 1.5 × 106 mol of product per mol of enzyme at 80 °C. This enzyme also exhibited high activities within a broad pH range of 6.0–9.0.
This ultra-thermostable TAL with high activity shows great potential for use in such applications as the production of enzymatic
biofuels production and the synthesis of high-value carbohydrates by cell-free synthetic pathway biotransformation. 相似文献
975.
976.
蔗糖合酶(sucrose synthase)与植物库强调节、次生壁的形成和纤维素合成等有着密切的联系,其中在纤维素合成过程中的作用尤为显著。本研究根据我们已获得的毛白杨PtSUS1基因片段设计引物,采用RACE技术,获得了毛白杨PtSUS1的基因序列,测序结果显示该基因序列全长为2 669 bp,包括一个完整的阅读框,编码805个氨基酸。通过Blast检索分析表明,PtSUS1与拟南芥、巨桉、陆地棉、温州蜜柑、毛果杨SUS1的核酸和氨基酸序列的同源性分别达到76%~97%和82%~97%。运用生物信息软件对PtSUS1编码的蛋白进行了二级结构预测和功能位点分析,结果显示该蛋白氨基酸序列包括两个功能域,存在可能的磷酸化位点38个,无跨膜结构域存在。系统进化分析表明PtSUS1与PtSUS2关系最为接近。RT-PCR分析结果显示,PtSUS1在被检测的毛白杨根、茎、叶及雌雄花芽组织和器官中均有表达,呈现组成型表达模式。该研究为进一步深入探索毛白杨蔗糖合酶基因PtSUS1的功能奠定了基础。 相似文献
978.
Chen Q Zhou Z Zhang L Wang Y Zhang YW Zhong M Xu SC Chen CH Li L Yu ZP 《Neurochemistry international》2012,60(3):233-242
Tau protein, a microtubule-associated protein involved in a number of neurological disorders such as Alzheimer's disease (AD), may undergo modifications under both physiological and pathological conditions. However, the signaling pathways that couple tau protein to neuronal physiology such as synaptic plasticity have not yet been elucidated. Here we report that tau protein is involved in morphological plasticity in response to brain derived neurotrophic factor (BDNF). Stimulation of the cultured rat hippocampal neurons with BDNF resulted in increased tau protein expression, as detected by Western blotting. Furthermore, tau protein accumulated in the distal region of the neurite when treated with taxol or taxol plus BDNF. The increased tau protein also protected neurons against nocodazole-induced dendrite loss. Moreover, BDNF promoted spine growth as well as tau protein over-expression. Knockdown of tau protein using specific short-hairpin RNA (shRNA) significantly decreased the spine density. And BDNF could not increase the spine density of tau-knockdown neurons. These results highlight a possible role for tau protein in the dynamic rearrangement of cytoskeletal fibers vital for BDNF-induced synaptic plasticity. 相似文献
979.
【目的】克隆斜卧青霉L-06的内切葡聚糖酶Ⅰ基因(egI),并实现其在大肠杆菌内的高效表达。【方法】利用RT-PCR技术克隆了斜卧青霉L-06的内切葡聚糖酶Ⅰ基因(egI),并将egI基因克隆到原核表达载体中,构建了重组质粒pET32a-egI。【结果】转化至大肠埃希菌Rosetta(DE3),经IPTG诱导重组蛋白表达,SDS-PAGE检测结果表明:重组表达产物的相对分子质量约为80 kD,与预期相符。重组表达的菌悬液,经破碎离心,取其上清液,进行纤维素酶活性染色,获得了活性条带。DNS法测得内切酶活力为2.56 IU/mL。【结论】构建了斜卧青霉L-06内切葡聚糖酶Ⅰ的原核表达系统。 相似文献
980.
Guo X Geng P Bai F Bai G Sun T Li X Shi L Zhong Q 《Letters in applied microbiology》2012,55(2):162-169
Aims: The aims of this study are to obtain the draft genome sequence of Streptomyces coelicoflavus ZG0656, which produces novel acarviostatin family α‐amylase inhibitors, and then to reveal the putative acarviostatin‐related gene cluster and the biosynthetic pathway. Methods and Results: The draft genome sequence of S. coelicoflavus ZG0656 was generated using a shotgun approach employing a combination of 454 and Solexa sequencing technologies. Genome analysis revealed a putative gene cluster for acarviostatin biosynthesis, termed sct‐cluster. The cluster contains 13 acarviostatin synthetic genes, six transporter genes, four starch degrading or transglycosylation enzyme genes and two regulator genes. On the basis of bioinformatic analysis, we proposed a putative biosynthetic pathway of acarviostatins. The intracellular steps produce a structural core, acarviostatin I00‐7‐P, and the extracellular assemblies lead to diverse acarviostatin end products. Conclusions: The draft genome sequence of S. coelicoflavus ZG0656 revealed the putative biosynthetic gene cluster of acarviostatins and a putative pathway of acarviostatin production. Significance and Impact of the Study: To our knowledge, S. coelicoflavus ZG0656 is the first strain in this species for which a genome sequence has been reported. The analysis of sct‐cluster provided important insights into the biosynthesis of acarviostatins. This work will be a platform for producing novel variants and yield improvement. 相似文献