排序方式: 共有94条查询结果,搜索用时 31 毫秒
11.
Takashi Sakudoh Tetsuya Iizuka Junko Narukawa Hideki Sezutsu Isao Kobayashi Seigo Kuwazaki Yutaka Banno Akitoshi Kitamura Hiromu Sugiyama Naoko Takada Hirofumi Fujimoto Keiko Kadono-Okuda Kazuei Mita Toshiki Tamura Kimiko Yamamoto Kozo Tsuchida 《The Journal of biological chemistry》2010,285(10):7739-7751
The transport pathway of specific dietary carotenoids from the midgut lumen to the silk gland in the silkworm, Bombyx mori, is a model system for selective carotenoid transport because several genetic mutants with defects in parts of this pathway have been identified that manifest altered cocoon pigmentation. In the wild-type silkworm, which has both genes, Yellow blood (Y) and Yellow cocoon (C), lutein is transferred selectively from the hemolymph lipoprotein to the silk gland cells where it is accumulated into the cocoon. The Y gene encodes an intracellular carotenoid-binding protein (CBP) containing a lipid-binding domain known as the steroidogenic acute regulatory protein-related lipid transfer domain. Positional cloning and transgenic rescue experiments revealed that the C gene encodes Cameo2, a transmembrane protein gene belonging to the CD36 family genes, some of which, such as the mammalian SR-BI and the fruit fly ninaD, are reported as lipoprotein receptors or implicated in carotenoid transport for visual system. In C mutant larvae, Cameo2 expression was strongly repressed in the silk gland in a specific manner, resulting in colorless silk glands and white cocoons. The developmental profile of Cameo2 expression, CBP expression, and lutein pigmentation in the silk gland of the yellow cocoon strain were correlated. We hypothesize that selective delivery of lutein to specific tissue requires the combination of two components: 1) CBP as a carotenoid transporter in cytosol and 2) Cameo2 as a transmembrane receptor on the surface of the cells. 相似文献
12.
Nishimura T Yamaguchi T Tokunaga A Hara A Hamaguchi T Kato K Iwamatsu A Okano H Kaibuchi K 《Molecular biology of the cell》2006,17(3):1273-1285
Numb has been implicated in cortical neurogenesis during nervous system development, as a result of its asymmetric partitioning and antagonizing Notch signaling. Recent studies have revealed that Numb functions in clathrin-dependent endocytosis by binding to the AP-2 complex. Numb is also expressed in postmitotic neurons and plays a role in axonal growth. However, the functions of Numb in later stages of neuronal development remain unknown. Here, we report that Numb specifically localizes to dendritic spines in cultured hippocampal neurons and is implicated in dendritic spine morphogenesis, partially through the direct interaction with intersectin, a Cdc42 guanine nucleotide exchange factor (GEF). Intersectin functions as a multidomain adaptor for proteins involved in endocytosis and cytoskeletal regulation. Numb enhanced the GEF activity of intersectin toward Cdc42 in vivo. Expression of Numb or intersectin caused the elongation of spine neck, whereas knockdown of Numb and Numb-like decreased the protrusion density and its length. Furthermore, Numb formed a complex with EphB2 receptor-type tyrosine kinase and NMDA-type glutamate receptors. Knockdown of Numb suppressed the ephrin-B1-induced spine development and maturation. These results highlight a role of Numb for dendritic spine development and synaptic functions with intersectin and EphB2. 相似文献
13.
Akitoshi Nakashima Mikiko Yamanaka-Tatematsu Naonobu Fujita Keiichi Koizumi Tomoko Shima Toshiko Yoshida Toshio Nikaido Aikou Okamoto Tamotsu Yoshimori Shigeru Saito 《Autophagy》2013,9(3):303-316
In early pregnancy, trophoblasts and the fetus experience hypoxic and low-nutrient conditions; nevertheless, trophoblasts invade the uterine myometrium up to one third of its depth and migrate along the lumina of spiral arterioles, replacing the maternal endothelial lining. Here, we showed that autophagy, an intracellular bulk degradation system, occurred in extravillous trophoblast (EVT) cells under hypoxia in vitro and in vivo. An enhancement of autophagy was observed in EVTs in early placental tissues, which suffer from physiological hypoxia. The invasion and vascular remodeling under hypoxia were significantly reduced in autophagy-deficient EVT cells compared with wild-type EVT cells. Interestingly, soluble endoglin (sENG), which increased in sera in preeclamptic cases, suppressed EVT invasion by inhibiting autophagy. The sENG-inhibited EVT invasion was recovered by TGFB1 treatment in a dose-dependent manner. A high dose of sENG inhibited the vascular construction by EVT cells and human umbilical vein endothelial cells (HUVECs), meanwhile a low dose of sENG inhibited the replacement of HUVECs by EVT cells. A protein selectively degraded by autophagy, SQSTM1, accumulated in EVT cells in preeclamptic placental biopsy samples showing impaired autophagy. This is the first report showing that impaired autophagy in EVT contributes to the pathophysiology of preeclampsia. 相似文献
14.
Ishikawa Junko Fujimura Shigeto Kondo Motohiko Murai-Hatano Mari Goto Akitoshi Shinano Takuro 《Plant and Soil》2018,424(1-2):503-524
Plant and Soil - In the Mediterranean basin, reduction in cloudiness owing to climate change is expected to enhance solar ultraviolet (UV) levels and to decrease rainfall over the coming years,... 相似文献
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16.
Hiroki Matsuyama Fumimasa Amaya Soshi Hashimoto Hiroshi Ueno Satoru Beppu Mitsuhiko Mizuta Nobuaki Shime Akitoshi Ishizaka Satoru Hashimoto 《Respiratory research》2008,9(1):1-13
Background
Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell migratory behavior.Methods
The effect of EGCG (at concentrations lower than 10 μg/ml) on the migration speed of invasive cells was assessed by using 2D and 3D models of cell culture. We also studied the effects of EGCG on proteinases expression by RT-PCR analysis. By immunocytochemistry, we analyzed alterations of vimentin organization in presence of different concentrations of EGCG.Results
We observed that EGCG had an inhibitory effect of cell migration in 2D and 3D cell culture models. EGCG also inhibited MMP-2 mRNA and protein expression and altered the intermediate filaments of vimentin.Conclusion
Taken together, our results demonstrate that EGCG is able to inhibit the migration of bronchial tumor cells and could therefore be an attractive candidate to treat tumor invasion and cell migration. 相似文献17.
Tatsuhisa Takahashi Taiji Nagaoka Hirotaka Yanagida Tadashi Saitoh Akira Kamiya Travis Hein Lih Kuo Akitoshi Yoshida 《Journal of Biorheology》2009,23(2):77-86
To quantitatively assess the arteriovenous distribution of hemodynamic parameters throughout the microvascular network of
the human retina, we constructed a retinal microcirculatory model consisting of a dichotomous symmetric branching system.
This system is characterized by a diameter exponent of 2.85, instead of 3 as dictated by Murray’s law, except for the capillary
networks. The value of 2.85 was the sum of a fractal dimension (1.70) and a branch exponent (1.15) of the retinal vasculature.
Following the feeding artery (central retinal artery), each bifurcation was recursively developed at a distance of an individual
branch length [L(r) = 7.4r
1.15] by a centrifugal scheme. The venular tree was formed in the same way. Using this model, we evaluated hemodynamic parameters,
including blood pressure, blood flow, blood velocity, shear rate, and shear stress, within the retinal microcirculatory network
as a function of vessel diameter. The arteriovenous distributions of blood pressure and velocity in the simulation were consistent
with in vivo measurements in the human retina and other vascular beds of small animals. We therefore conclude that the current
theoretical model was useful for quantifying hemodynamics as a function of vessel diameter within the retinal microvascular
network. 相似文献
18.
Newcastle disease virus grown in embryonated eggs was separated and purified by sucrose density gradient centrifugation into two distinct types of particles, B and T, the former being normal virus particles with high activities of hemagglutination, hemolysis, neuraminidase and infectivity, the latter being non-infectious virus particles with low activities of hemolysis and neuraminidase but high hemagglutination activity. B and T particles were shown to share a common antigen by immunodiffusion test. T particles were deficient in viral RNA, since they contained only 13s RNA in a small amount, whereas B particles possessed a large amount of 57s RNA and a small amount of 13s RNA. T particles interfered with the multiplication of normal Newcastle disease virus in primary cultures of chick embryo cells. 相似文献
19.
Iwamoto A Satoh D Furutani M Maruyama S Ohba H Sugiyama M 《Journal of plant research》2006,119(2):85-93
Plant organ growth changes under genetic and environmental influences can be observed as altered cell proliferation and volume growth. The two aspects are mutually dependent and intricately related. For comprehensive growth analysis, it is necessary to specify the relationship quantitatively. Here, we develop a simple mathematical model for this purpose. Our model assumes that the biological activity of a given organ is proportional to the cell number of the organ and is allocated into three aspects: cell proliferation, volume growth, and organ maintenance. We analyzed the growth of primary roots of Arabidopsis thaliana (L.) Heynh. in one tetraploid and four diploid strains using this model. The analysis determined various growth parameters, such as specific cost coefficients of cell proliferation and volume growth for each strain. The results provide insight into the basis of interstrain variations and ploidy effects in root growth. 相似文献
20.
Yurika Yogo Seitaro Fujishima Takashi Inoue Fumitake Saito Takayuki Shiomi Kazuhiro Yamaguchi Akitoshi Ishizaka 《Respiratory research》2009,10(1):80