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81.
Jinyan Wang Qian Zhang Dandan Wang Sujin Yang Siying Zhou Hanzi Xu Heda Zhang Shanliang Zhong Jifeng Feng 《Journal of cellular physiology》2020,235(7-8):5722-5735
We aimed to investigate the role of exosomal miR-4443 in metastasis of breast cancer (BCa). In vitro wound-healing assay and transwell invasion assay were used to investigate effect of miR-4443 on BCa cells. Animal experiments were performed to confirm its effects in vivo. miR-4443 promotes the metastasis of BCa cells through downregulating tissue inhibitors of metalloproteinase 2 (TIMP2) and upregulating matrix metalloproteinases (MMPs). Highly invasive BCa cells have a higher expression of miR-4443 in both cells and exosomes. The exosomes derived from highly invasive BCa cells mainly gather in the primary tumor and liver. In vivo, overexpression of miR-4443 in noninvasive BCa cells induces liver metastasis, accompanied with downregulated TIMP2, and upregulated MMP-2 in both the primary tumor and liver. When we armed MCF-10A exosomes with miR-4443 inhibitors to treat mice bearing high-miR-4443 tumors, exosomes accumulated in the primary tumor, and liver following the upregulation of TIMP2 and downregulation of MMP2, and the metastasis was inhibited. Highly invasive BCa cells destroy natural barriers against metastasis by delivering exosomal miR-4443 to stromal cells of the primary tumor and impairing TIMP2, consequently activating MMP; circulating exosomal miR-4443 might promote BCa cells lodging in future metastatic sites through the similar mechanisms. 相似文献
82.
Saúl Herranz-Martín David Jimeno Antonio E. Paniagua Almudena Velasco Juan M. Lara José Aijón Concepción Lillo 《PloS one》2012,7(11)
CRB3 (Crumbs homologue 3), a member of the CRB protein family (homologous to the Drosophila Crumbs), is expressed in different epithelium-derived cell types in mammals, where it seems to be involved in regulating the establishment and stability of tight junctions and in ciliogenesis. This protein has been also detected in the retina, but little is known about its localization and function in this tissue. Our goal here was to perform an in-depth study of the presence of CRB3 protein in the mouse retina and to analyze its expression during photoreceptor ciliogenesis and the establishment of the plexiform retinal layers. Double immunofluorescence experiments for CRB3 and well-known markers for the different retinal cell types were performed to study the localization of the CRB3 protein. According to our results, CRB3 is present from postnatal day 0 (P0) until adulthood in the mouse retina. It is localized in the inner segments (IS) of photoreceptor cells, especially concentrated in the area where the connecting cilium is located, in their synaptic terminals in the outer plexiform layer (OPL), and in sub-populations of amacrine and bipolar cells in the inner plexiform layer (IPL). 相似文献
83.
84.
Capsule The nesting success of the Woodpigeon Columba palumbus in oak forests in Morocco is affected by human disturbance and nest-site characteristics. Aims To determine factors affecting the nesting success of Woodpigeons subject to two levels of disturbance in a holm oak Middle Atlas forest. Methods Woodpigeon nests were monitored in highly disturbed (n?=?30) and less-disturbed sites (n?=?60) over two years (2010–11). Logistic-exposure models were used to estimate daily nest-survival rate and evaluate mechanisms (altitude, temporal factors, nest location, nest-site habitat and degree of human influence) affecting nest survival. Results Daily nest-survival rate was higher in less-disturbed sites (0.987; 95% CL: 0.980–0.991) than in high-disturbance sites (0.967; 95% CL: 0.949–0.978). Increasing density of trees surrounding nest sites and distance from the nest tree to the closest track increased daily nest-survival rate. Conclusions Less-disturbed sites confer better nesting conditions than highly disturbed ones. Management measures should control the access of vehicles, especially trucks, in the forest of the Middle Atlas and introduce a grazing regime that will allow the forest regeneration, which would improve Woodpigeon nesting success by increasing the density of holm oak trees. 相似文献
85.
Paulo De Sa Peixoto Guillaume Laurent Thierry Aza?s Gervaise Mosser 《The Journal of biological chemistry》2013,288(11):7528-7535
In vivo, collagen I, the major structural protein in human body, is found assembled into fibrils. In the present work, we study a high concentrated collagen sample in its soluble, fibrillar, and denatured states using one and two dimensional {1H}-13C solid-state NMR spectroscopy. We interpret 13C chemical shift variations in terms of dihedral angle conformation changes. Our data show that fibrillogenesis increases the side chain and backbone structural complexity. Nevertheless, only three to five rotameric equilibria are found for each amino acid residue, indicating a relatively low structural heterogeneity of collagen upon fibrillogenesis. Using side chain statistical data, we calculate equilibrium constants for a great number of amino acid residues. Moreover, based on a 13C quantitative spectrum, we estimate the percentage of residues implicated in each equilibrium. Our data indicate that fibril formation greatly affects hydroxyproline and proline prolyl pucker ring conformation. Finally, we discuss the implication of these structural data and propose a model in which the attractive force of fibrillogenesis comes from a structural reorganization of 10 to 15% of the amino acids. These results allow us to further understand the self-assembling process and fibrillar structure of collagen. 相似文献
86.
Igor Marjanovič Saša Haberl Damijan Miklavčič Maša Kandušer Mojca Pavlin 《The Journal of membrane biology》2010,236(1):97-105
Knowledge of the parameters which influence the efficiency of gene electrotransfer has importance for practical implementation
of electrotransfection for gene therapy as well as for better understanding of the underlying mechanism. The focus of this
study was to analyze the differences in gene electrotransfer and membrane electropermeabilization between plated cells and
cells in a suspension in two different cell lines (CHO and B16F1). Furthermore, we determined the viability and critical induced
transmembrane voltage (ITVc) for both cell lines. In plated cells we obtained relatively little difference in electropermeabilization and gene electrotransfection
between CHO and B16F1 cells. However, significant differences between the two cell lines were observed in a suspension. CHO
cells exhibited a much higher gene electrotransfection rate compared to B16F1 cells, whereas B16F1 cells reached maximum electropermeabilization
at lower electric fields than CHO cells. Both in a suspension and on plated cells, CHO cells had a slightly better survival
rate at higher electric fields than B16F1 cells. Calculation of ITVc in a suspension showed that, for both electropermeabilization and gene electrotransfection, CHO cells have lower ITVc than B16F1 cells. In all cases, ITVc for electropermeabilization was lower than ITVc for gene electrotransfer, which is in agreement with other studies. Our results show that there is a marked difference in
the efficiency of gene electrotransfer between suspended and plated cells. 相似文献
87.
Cüneyt Çirak Birsen Sağlam Ali Kemal Ayan Kudret Kevseroğlu 《Biochemical Systematics and Ecology》2006
The genus Hypericum has received considerable interest from scientists, as it is a source of a variety of biologically active compounds including the hypericins. The present study was conducted to determine ontogenetic, morphogenetic and diurnal variation of the total hypericins content in some species of Hypericum growing in Turkey namely, Hypericum aviculariifolium subsp. depilatum var. depilatum (endemic), Hypericum perforatum and Hypericum pruinatum. The Hypericum plants were harvested from wild populations at vegetative, floral budding, full flowering, fresh fruiting and mature fruiting stages four times a day. Plants were dissected into stem, leaf and reproductive tissues, which were dried separately, and subsequently assayed for total hypericin content. The density of dark glands on leaves at full flowering plants was determined for each species. Floral parts had the highest hypericin content in all species tested. But diurnal fluctuation in the hypericin content of whole plant during the course of ontogenesis varied among the species. It reached the highest level at floral budding and tended to increase at night in H. aviculariifolium subsp. depilatum var. depilatum and H. pruinatum, whereas in H. perforatum hypericin content was the highest at full flowering and no diurnal fluctuation was observed. In general, hypericin content of leaves and whole plant was higher in H. aviculariifolium subsp. depilatum var. depilatum whose leaves had more numerous dark glands than those of the two other species. 相似文献
88.
Nitrogen (N) availability is a major factor limiting plant production in many terrestrial ecosystems and is a key regulator of plant response to elevated CO2. Plant N status is a function of both soil N availability and plant N uptake and assimilation capacity. As a rate-limiting step in nitrate assimilation, the reduction of nitrate is an important component of plant physiological response to elevated CO2 and terrestrial carbon sequestration. We examine the effects of elevated CO2 and N availability on the activity of nitrate reductase, the enzyme catalyzing the reduction of nitrate to nitrite, in two temperate forests—a closed canopy sweetgum (Liquidambar styraciflua) plantation in Tennessee (Oak Ridge National Laboratory (ORNL)) and a loblolly pine (Pinus taeda) stand in North Carolina (Duke). Both CO2 and N enrichment had species specific impacts on nitrate reductase activity (NaR). Elevated CO2 and N fertilization decreased foliar NaR in P. taeda, but there were no treatment effects on L. styraciflua NaR at ORNL or Duke. NaR in 1-year P. taeda needles was significantly greater than in 0-year old needles across treatments. P. taeda NaR was negatively correlated with bio-available molybdenum concentrations in soils, suggesting that CO2 and N-mediated changes in soil nutrient status may be altering soil-plant N-dynamics. The variation in response among species may reflect different strategies for acquiring N and suggests that elevated CO2 may alter plant N dynamics through changes in NaR. 相似文献
89.
抗人肺腺癌单克隆抗体重,轻链可变区基因的分离克隆和序列测定 总被引:5,自引:1,他引:5
根据鼠免疫球蛋白重。轻链可变区基因FR1和FR4的序列保守性,化学合成了适于体外扩增Ig重、轻链可变区基因(V_H和V_L)的数对引物。以分泌抗人肺腺癌单抗的杂交瘤细胞株WLA-2C4的基因组DNA为模板,PCR扩增V_H和V_L基因,分别克隆人pUC19载体。转化子经蓝、白斑筛选,酶切鉴定,双脱氧测序证实确为鼠单抗可变区基因,其中V_H基因全长为348bp,编码116aa,属重链ⅡB亚类;V_L基因全长318bp,编码106aa,属K轻链Ⅵ亚类。 相似文献
90.
Bel Hadj Ali I Thys M Beltaief N Schrauwen I Hilgert N Vanderstraeten K Dieltjens N Mnif E Hachicha S Besbes G Ben Arab S Van Camp G 《Human genetics》2008,123(3):267-272
Otosclerosis is a common disorder of the otic capsule resulting in hearing impairment in 0.3–0.4% of the Caucasian population.
The aetiology of the disease remains unclear. In most cases, otosclerosis can be considered as a complex disease. In some
cases, the disease is inherited as an autosomal dominant trait, sometimes with reduced penetrance. To date, seven autosomal
dominant loci have been reported, but none of the disease-causing genes has been identified. In this study, we present the
results of a genome-wide linkage analysis in a large Tunisian family segregating autosomal dominant otosclerosis. Linkage
analysis localised the responsible gene to chromosome 9p13.1-9q21.11 with a maximal LOD score of 4.13, and this locus was
named OTSC8. Using newly generated short tandem repeat polymorphism markers, we mapped this new otosclerosis locus to a 34.16 Mb interval
between the markers D9S970 and D9S1799. This region comprises the pericentromeric region on both arms of chromosome 9, a highly
complex region containing many duplicated sequences.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献