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51.
Troponin T (TnT) isoforms of chicken fast skeletal muscle are classified into two types, breast-muscle-type (B-type) and leg-muscle-type (L-type) isoforms. These isoforms are produced from a single gene by differential alternative splicing of pre-mRNA. We investigated immunohistochemically the distribution of B-type TnT isoforms in chicken leg muscle (musculus biceps femoris), using anti-exon x3 that was raised against a synthetic peptide corresponding to exon x3 and recognized B-type, but not the L-type, TnT isoforms. Mosaic patterns of immunostaining showing locally different expression of B-type TnT isoforms in a single fiber were observed among fibers, and the non-uniform distribution of the isoforms was also detected in sectioned fibers and myofibrils from the muscle. The results indicated that regulation of pre-mRNA splicing of fast skeletal muscle TnT was different not only among the muscle fibers but also within a single fiber, suggesting that heterogeneous myonuclei in regulation of alternative splicings occur in a single muscle fiber. 相似文献
52.
Function of 90-kDa heat shock protein in cellular differentiation of human embryonal carcinoma cells
Yamada T Hashiguchi A Fukushima S Kakita Y Umezawa A Maruyama T Hata J 《In vitro cellular & developmental biology. Animal》2000,36(2):139-146
Summary Heat shock proteins (HSPs) have been recognized as molecules that maintain cellular homeostasis during changes in the environment.
Here we report that HSP90 functions not only in stress responses but also in certain aspects of cellular differentiation.
We found that HSP90 slowed remarkably high expression in undifferentiated human embryonal carcinoma (EC) cells, which were
subsequently dramatically down-regulated during in vitro cellular differentiation, following retinoic acid (RA) treatment,
at the protein level. Surprisingly, heat shock treatment also triggered the down-regulation of HSP90 within 48 h at the protein
level. Furthermore, the heat treatment induced cellular differentiation into neural cells. This down-regulation of HSP90 by
heat treatment was shifted to an up-regulation attern after cellular differentiation in response to RA treatment. In order
to clarify the functions of HSP90 in cellular differentiation, we conducted various experiments, including overexpression
of HSP90 via gene transfer. We showed that the RA-induced differentiation of EC cells into a neural cell lineage was inhibited
by overexpression of the HSP90α or-β isoform via the gene transfer method. On the other hand, the overexpression of HSP90β
alone impaired cellular differentiation into trophoectoderm. These results show that down-regulation of HSP90 is a physiological
critical event in the differentiation of human EC cells and that specific HSP90 isoforms may be involved in differentiation
into specific cell lineages. 相似文献
53.
54.
Jun-Ichi Sasaki Masanori Hashimoto Satoshi Yamaguchi Yoshihiro Itoh Itsumi Yoshimoto Takuya Matsumoto Satoshi Imazato 《PloS one》2015,10(6)
The development of technologies to promote vascularization of engineered tissue would drive major developments in tissue engineering and regenerative medicine. Recently, we succeeded in fabricating three-dimensional (3D) cell constructs composed of mesenchymal stem cells (MSCs). However, the majority of cells within the constructs underwent necrosis due to a lack of nutrients and oxygen. We hypothesized that incorporation of vascular endothelial cells would improve the cell survival rate and aid in the fabrication of biomimetic bone tissues in vitro. The purpose of this study was to assess the impact of endothelial cells combined with the MSC constructs (MSC/HUVEC constructs) during short- and long-term culture. When human umbilical vein endothelial cells (HUVECs) were incorporated into the cell constructs, cell viability and growth factor production were increased after 7 days. Furthermore, HUVECs were observed to proliferate and self-organize into reticulate porous structures by interacting with the MSCs. After long-term culture, MSC/HUVEC constructs formed abundant mineralized matrices compared with those composed of MSCs alone. Transmission electron microscopy and qualitative analysis revealed that the mineralized matrices comprised porous cancellous bone-like tissues. These results demonstrate that highly biomimetic bone tissue can be fabricated in vitro by 3D MSC constructs incorporated with HUVECs. 相似文献
55.
Masaharu Tsubokura Shigeaki Kato Tomohiro Morita Shuhei Nomura Masahiro Kami Kikugoro Sakaihara Tatsuo Hanai Tomoyoshi Oikawa Yukio Kanazawa 《PloS one》2015,10(6)
An assessment of the external and internal radiation exposure levels, which includes calculation of effective doses from chronic radiation exposure and assessment of long-term radiation-related health risks, has become mandatory for residents living near the nuclear power plant in Fukushima, Japan. Data for all primary and secondary children in Minamisoma who participated in both external and internal screening programs were employed to assess the annual additional effective dose acquired due to the Fukushima Daiichi nuclear power plant disaster. In total, 881 children took part in both internal and external radiation exposure screening programs between 1st April 2012 to 31st March 2013. The level of additional effective doses ranged from 0.025 to 3.49 mSv/year with the median of 0.70 mSv/year. While 99.7% of the children (n = 878) were not detected with internal contamination, 90.3% of the additional effective doses was the result of external radiation exposure. This finding is relatively consistent with the doses estimated by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). The present study showed that the level of annual additional effective doses among children in Minamisoma has been low, even after the inter-individual differences were taken into account. The dose from internal radiation exposure was negligible presumably due to the success of contaminated food control. 相似文献
56.
Shoichiro Ozaki Etsuko Ebisui Kozo Hamada Jun-Ichi Goto Akinobu Z. Suzuki Akiko Terauchi Katsuhiko Mikoshiba 《Bioorganic & medicinal chemistry letters》2010,20(3):1141-1144
Aryl β-aminoethyl ketones were discovered as potent inhibitors of tissue transglutaminase. Heteroaryl-like thiophene groups and N-benzyl N-t-butyl aminoethyl group are critical to the strong inhibitory activity of aryl β-aminoethyl ketones. 相似文献
57.
Acetylated YY1 regulates Otx2 expression in anterior neuroectoderm at two cis-sites 90 kb apart
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The mouse homeobox gene Otx2 plays essential roles at each step and in every tissue during head development. We have previously identified a series of enhancers that are responsible for driving the Otx2 expression in these contexts. Among them the AN enhancer, existing 92 kb 5' upstream, directs Otx2 expression in anterior neuroectoderm (AN) at the headfold stage. Analysis of the enhancer mutant Otx2(DeltaAN/-) indicated that Otx2 expression under the control of this enhancer is essential to the development of AN. This study demonstrates that the AN enhancer is promoter-dependent and regulated by acetylated YY1. YY1 binds to both the AN enhancer and promoter region. YY1 is acetylated in the anterior head, and only acetylated YY1 can bind to the sequence in the enhancer. Moreover, YY1 binding to both of these two sites is essential to Otx2 expression in AN. These YY1 binding sites are highly conserved in AN enhancers in tetrapods, coelacanth and skate, suggesting that establishment of the YY1 regulation coincides with that of OTX2 function in AN development in an ancestral gnathostome. 相似文献
58.
A synthetic pathway was engineered in Escherichia coli to produce isopropanol by expressing various combinations of genes from Clostridium acetobutylicum ATCC 824, E. coli K-12 MG1655, Clostridium beijerinckii NRRL B593, and Thermoanaerobacter brockii HTD4. The strain with the combination of C. acetobutylicum thl (acetyl-coenzyme A [CoA] acetyltransferase), E. coli atoAD (acetoacetyl-CoA transferase), C. acetobutylicum adc (acetoacetate decarboxylase), and C. beijerinckii adh (secondary alcohol dehydrogenase) achieved the highest titer. This strain produced 81.6 mM isopropanol in shake flasks with a yield of 43.5% (mol/mol) in the production phase. To our knowledge, this work is the first to produce isopropanol in E. coli, and the titer exceeded that from the native producers. 相似文献
59.
Ikebe J Kamiya N Ito J Shindo H Higo J 《Protein science : a publication of the Protein Society》2007,16(8):1596-1608
The monomeric Alzheimer's beta amyloid peptide, Abeta, is known to adopt a disordered state in water at room temperature, and a circular dichroism (CD) spectroscopy experiment has provided the secondary-structure contents for the disordered state: 70% random, 25% beta-structural, and 5% helical. We performed an enhanced conformational sampling (multicanonical molecular dynamics simulation) of a 25-residue segment (residues 12-36) of Abeta in explicit water and obtained the conformational ensemble over a wide temperature range. The secondary-structure contents calculated from the conformational ensemble at 300 degrees K reproduced the experimental secondary-structure contents. The constructed free-energy landscape at 300 degrees K was not plain but rugged with five clearly distinguishable clusters, and each cluster had its own characteristic tertiary structure: a helix-structural cluster, two beta-structural clusters, and two random-structural clusters. This indicates that the contribution from the five individual clusters determines the secondary-structure contents experimentally measured. The helical cluster had a similarity with a stable helical structure for monomeric Abeta in 2,2,2-trifluoroethanol (TFE)/water determined by an NMR experiment: The positions of helices in the helical cluster were the same as those in the NMR structure, and the residue-residue contact patterns were also similar with those of the NMR structure. The cluster-cluster separation in the conformational space indicates that free-energy barriers separate the clusters at 300 degrees K. The two beta-structural clusters were characterized by different strand-strand hydrogen-bond (H-bond) patterns, suggesting that the free-energy barrier between the two clusters is due to the H-bond rearrangements. 相似文献
60.
Development, characterization, and comparative analysis of polymorphism at common bean SSR loci isolated from genic and genomic sources. 总被引:4,自引:0,他引:4
Luiz Ricardo Hanai Tatiana de Campos Luis Eduardo Aranha Camargo Luciana Lasry Benchimol Anete Pereira de Souza Maeli Melotto Sérgio Augusto Moraes Carbonell Alisson Fernando Chioratto Luciano Consoli Eduardo Fernando Formighieri Marcos Vinícius Bohrer Monteiro Siqueira Siu Mui Tsai Maria Lucia Carneiro Vieira 《Génome》2007,50(3):266-277
Microsatellites or SSRs (single sequence repeats) have been used to construct and integrate genetic maps in crop species, including Phaseolus vulgaris. In the present study, 3 cDNA libraries generated by the Bean EST project (http://lgm.esalq.usp.br/BEST/), comprising a unigene collection of 3126 sequences and a genomic microsatellite-enriched library, were analyzed for the presence of SSRs. A total of 219 expressed sequence tags (ESTs) were found to carry 240 SSRs (named EST-SSR), whereas 714 genomic sequences contained 471 SSRs (named genomic-SSR). A subset of 80 SSRs, 40 EST-SSRs, and 40 genomic-SSRs were evaluated for molecular polymorphism in 23 genotypes of cultivated beans from the Mesoamerican and Andean genetic pools, including Brazilian cultivars and 2 related species. Of the common bean genotypes, 31 EST-SSR loci were polymorphic, yielding 2-12 alleles as compared with 26 polymorphic genomic-SSRs, accounting for 2-7 alleles. Cluster analysis from data using both genic and genomic-SSR revealed a clear separation between Andean and Mesoamerican beans. The usefulness of these loci for distinguishing bean genotypes and genetic mapping is discussed. 相似文献