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991.
Accelerated fat absorption in intestinal alkaline phosphatase knockout mice 总被引:1,自引:0,他引:1 下载免费PDF全文
Narisawa S Huang L Iwasaki A Hasegawa H Alpers DH Millán JL 《Molecular and cellular biology》2003,23(21):7525-7530
Intestinal alkaline phosphatase (IAP) is the most ancestral of the tissue-specific members of the AP gene family. Several studies have suggested an absorptive function for IAP, but in vivo data to this effect have been lacking. We inactivated the mouse IAP gene in embryo-derived stem cells and generated mice homozygous for the null mutation. The mice were macroscopically and histologically normal and fertile and showed no difference from the wild-type controls under normal laboratory conditions. However, when maintained long-term on a high-fat diet, the IAP-deficient mice showed faster body weight gain than did control animals. Histological examination revealed an accelerated transport of fat droplets through the intestinal epithelium and elevation of serum triglyceride levels in the IAP-deficient mice compared to wild-type mice. Our study suggests that IAP participates in a rate-limiting step regulating fat absorption. 相似文献
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993.
Takeshi Sakuno Sanki Tashiro Hideki Tanizawa Osamu Iwasaki Da-Qiao Ding Tokuko Haraguchi Ken-ichi Noma Yasushi Hiraoka 《Nucleic acids research》2022,50(7):3799
During meiotic prophase, cohesin-dependent axial structures are formed in the synaptonemal complex (SC). However, the functional correlation between these structures and cohesion remains elusive. Here, we examined the formation of cohesin-dependent axial structures in the fission yeast Schizosaccharomyces pombe. This organism forms atypical SCs composed of linear elements (LinEs) resembling the lateral elements of SC but lacking the transverse filaments. Hi-C analysis using a highly synchronous population of meiotic S. pombe cells revealed that the axis-loop chromatin structure formed in meiotic prophase was dependent on the Rec8 cohesin complex. In contrast, the Rec8-mediated formation of the axis-loop structure occurred in cells lacking components of LinEs. To dissect the functions of Rec8, we identified a rec8-F204S mutant that lost the ability to assemble the axis-loop structure without losing cohesion of sister chromatids. This mutant showed defects in the formation of the axis-loop structure and LinE assembly and thus exhibited reduced meiotic recombination. Collectively, our results demonstrate that the Rec8-dependent axis-loop structure provides a structural platform essential for LinE assembly, facilitating meiotic recombination of homologous chromosomes, independently of its role in sister chromatid cohesion. 相似文献
994.
Fundamental cell cycle kinases collaborate to ensure timely destruction of the synaptonemal complex during meiosis 下载免费PDF全文
Bilge Argunhan Wing‐Kit Leung Negar Afshar Yaroslav Terentyev Vijayalakshmi V Subramanian Yasuto Murayama Andreas Hochwagen Hiroshi Iwasaki Tomomi Tsubouchi Hideo Tsubouchi 《The EMBO journal》2017,36(17):2488-2509
The synaptonemal complex (SC) is a proteinaceous macromolecular assembly that forms during meiotic prophase I and mediates adhesion of paired homologous chromosomes along their entire lengths. Although prompt disassembly of the SC during exit from prophase I is a landmark event of meiosis, the underlying mechanism regulating SC destruction has remained elusive. Here, we show that DDK (Dbf4‐dependent Cdc7 kinase) is central to SC destruction. Upon exit from prophase I, Dbf4, the regulatory subunit of DDK, directly associates with and is phosphorylated by the Polo‐like kinase Cdc5. In parallel, upregulated CDK1 activity also targets Dbf4. An enhanced Dbf4‐Cdc5 interaction pronounced phosphorylation of Dbf4 and accelerated SC destruction, while reduced/abolished Dbf4 phosphorylation hampered destruction of SC proteins. SC destruction relieved meiotic inhibition of the ubiquitous recombinase Rad51, suggesting that the mitotic recombination machinery is reactivated following prophase I exit to repair any persisting meiotic DNA double‐strand breaks. Taken together, we propose that the concerted action of DDK, Polo‐like kinase, and CDK1 promotes efficient SC destruction at the end of prophase I to ensure faithful inheritance of the genome. 相似文献
995.
Kenta Iwasaki Takayuki Yamamoto Yukiko Inanaga Takahisa Hiramitsu Yuko Miwa Kenta Murotani 《Biomarkers》2017,22(1):45-54
De novo donor-specific HLA antibody (DSA) would not necessarily contribute to chronic antibody-mediated rejection (CAMR) in kidney transplantation. Here, we investigated whether PBMC miRNAs could be predictable biomarkers for CAMR. Microarray profiling of 435 mature miRNAs in pooled samples was conducted. Individual analysis revealed that miR-142-5p was significantly (p?<?0.01) underexpressed in patients with DSA. After DSA production, miR-486-5p and its target PTEN/foxO3 mRNA were significantly overexpressed (p?<?0.01) and underexpressed (p?<?0.01), respectively, in patients with biopsy-proven CAMR, compared with non-CAMR. Our studies suggest that miRNA expression patterns may serve as noninvasive diagnostic biomarkers to evaluate immune response and kidney allograft status. 相似文献
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997.
CD11b+ Peyer's patch dendritic cells secrete IL-6 and induce IgA secretion from naive B cells 总被引:8,自引:0,他引:8
Sato A Hashiguchi M Toda E Iwasaki A Hachimura S Kaminogawa S 《Journal of immunology (Baltimore, Md. : 1950)》2003,171(7):3684-3690
Peyer's patch (PP) dendritic cells (DCs) have been shown to exhibit a distinct capacity to induce cytokine secretion from CD4(+) T cells compared with DCs in other lymphoid organs such as the spleen (SP). In this study, we investigated whether PP DCs are functionally different from DCs in the SP in their ability to induce Ab production from B cells. Compared with SP DCs, freshly isolated PP DCs induced higher levels of IgA secretion from naive B cells in DC-T cell-B cell coculture system in vitro. The IgA production induced by PP DCs was attenuated by neutralization of IL-6. In addition, the induction of IgA secretion by SP DCs, but not PP DCs, was further enhanced by the addition of exogenous IL-6. Finally, we demonstrated that only PP CD11b(+) DC subset secreted higher levels of IL-6 compared with other DC subsets in the PP and all SP DC populations, and that PP CD11b(+) DC induced naive B cells to produce higher levels of IgA compared with SP CD11b(+) DC. These results suggest a unique role of PP CD11b(+) DCs in enhancing IgA production from B cells via secretion of IL-6. 相似文献
998.
Lokugamage N Kariwa H Lokugamage K Iwasa MA Hagiya T Yoshii K Tachi A Ando S Fukushima H Tsuchiya K Iwasaki T Araki K Yoshimatsu K Arikawa J Mizutani T Osawa K Sato H Takashima I 《Microbiology and immunology》2004,48(11):843-851
Epizootiological surveys on hantavirus infections in rodents were carried out in various areas of Japan, including the four major islands of Hokkaido, Honshu, Shikoku, and Kyushu from 2000 to 2003. A total of 1,221 rodents and insectivores were captured. Seropositive animals were found in Apodemus (A.) speciosus (5/482, 1.0%), Rattus (R.) norvegicus (4/364, 1.1%), R. rattus (3/45, 6.7%), and Clethrionomys (C.) rufocanus (7/197, 3.6%). The partial S segment was amplified from one seropositive R. rattus captured at Hakodate. The nucleotide sequence showed 96% identity with the Seoul virus (SEOV) prototype strain SR-11. In addition, we conducted an epidemiological survey on human hantavirus infection in a high-risk population, the personnel of the Japan Ground Self-defense Force on Hokkaido. One out of 207 human blood samples was positive for anti-hantavirus antibody by IFA, ELISA, and WB analysis. The result of the serotype specific ELISA indicates that this individual acquired SEOV infection. This study indicates that A. speciosus, R. norvegicus, R. rattus, and C. rufocanus carry hantaviruses as the reservoir animals in Japan. Infected R. rattus and R. norvegicus in port areas could be the sources of human SEOV infection and a threat to travelers and individuals working in seaports. 相似文献
999.
Satoko Nagase Masahiro Yamanari Ryosuke Tanaka Takeshi Yasui Masahiro Miura Takuya Iwasaki Hiroshi Goto Yoshiaki Yasuno 《PloS one》2013,8(3)
Purpose
To investigate the relationship between scleral mechanical properties, its birefringence, and the anisotropy of birefringence alteration in respect of the direction of the strain by using PS-OCT.Methods
The scleral birefringence of thirty-nine porcine eyes was measured with a prototype PS-OCT. A rectangle strip of sclera with a width of 4 mm was dissected at the temporal region 5 mm apart from the optic nerve head. The strain and force were measured with a uniaxial tension tester as the sample was stretched with a speed of 1.8 mm/min after preconditioning. The birefringence of the sample was measured by PS-OCT at the center of the sample before applying, denoted as inherent birefringence, and after applying stretching of 6.5% strain. The birefringence alteration was obtained by these two measurements and correlations between birefringence and elastic parameters, tangent modulus, and structural stiffness were examined. Twenty and 19 porcine eyes were stretched in meridional or equatorial directions, respectively.Results
A moderate positive correlation was found between the inherent birefringence and the structural stiffness. A moderate positive correlation was also found between the inherent birefringence and the tangent modulus. The birefringence increased by strains. Marginal significance was found in the birefringence alteration between meridional and equatorial strains, where the mean birefringence elevation by meridional strain was higher than that by equatorial strain.Conclusions
The birefringence was found to be altered by applying strain and also be related with inherent birefringence. This implies the birefringence of the sclera of the in vivo eye also could be affected by its mechanical property. 相似文献1000.
Hideki Sudo Katsuhisa Yamada Koji Iwasaki Hideaki Higashi Manabu Ito Akio Minami Norimasa Iwasaki 《PloS one》2013,8(3)