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排序方式: 共有1207条查询结果,搜索用时 15 毫秒
981.
Shintaro Hashimoto Masaki Honda Takayuki Takeichi Masataka Sakisaka Yasuko Narita Daiki Yoshii Keiichi Uto Seisuke Sakamoto Yukihiro Inomata 《Biochemical and biophysical research communications》2018,495(3):2296-2302
Background
Neutrophils are known to be key players in innate immunity. Activated neutrophils induce local inflammation, which results in pathophysiologic changes during intestinal ischemia-reperfusion injury (IRI). However, most studies have been based on static assessments, and few have examined real-time intravital neutrophil recruitment. We herein report a method for imaging and evaluating dynamic changes in the neutrophil recruitment in intestinal IRI using two-photon laser scanning microscopy (TPLSM).Methods
LysM-eGFP mice were subjected to 45?min of warm intestinal ischemia followed by reperfusion. Mice received an intravenous injection of tetramethylrhodamine isothiocyanate-labeled albumin to visualize the microvasculature. Using a time-lapse TPLSM technique, we directly observed the behavior of neutrophils in intestinal IRI.Results
We were able to image all layers of the intestine without invasive surgical stress. At low-magnification, the number of neutrophils per field of view continued to increase for 4?h after reperfusion. High-magnification images revealed the presence or absence of blood circulation. At 0–2?h after reperfusion, rolling and adhesive neutrophils increased along the vasculature. At 2–4?h after reperfusion, the irregularity of crypt architecture and transmigration of neutrophils were observed in the lamina propria. Furthermore, TPLSM imaging revealed the villus height, the diameters of the crypt, and the number of infiltrating neutrophils in the crypt. In the IRI group, the villus height 4?h after reperfusion was significantly shorter than in the control group.Conclusions
TPLSM imaging revealed the real-time neutrophil recruitment in intestinal IRI. Z-stack imaging was useful for evaluating pathophysiological changes in the intestinal wall. 相似文献982.
Yasuko Yoshinaka Satoko Soga Keiichi Yokoyama Yosuke Yamada Misaka Kimura 《Bioscience, biotechnology, and biochemistry》2018,82(4):677-682
AbstractThis study aimed to investigate the efficacy of home-based, light gymnastic exercise plus dietary milk fat globule membrane (MFGM) intake on physical fitness of an elderly Japanese sample in a pilot, double-blind, randomized, placebo-controlled trial. Seventy-one subjects (male, n = 13; female, n = 58) were randomly assigned into two groups: placebo (n = 35 [male, n = 6; female, n = 29]) and MFGM group (n = 36 [male, n = 7; female, n = 29]). The intervention was eight weeks. Subjects ingested either MFGM (1 g/day) or placebo tablets daily and engaged in an exercise program daily. Physical function tests were performed at baseline and after four and eight weeks. Foot tapping and open–close stepping scores significantly increased from baseline to eight weeks in the MFGM group. Study results suggest daily MFGM ingestion might further enhance the effects of light-intensity exercise in healthy elderly people. 相似文献
983.
In a previous paper, we reported that the Neurospora crassa upr-1 gene is a homolog of the yeast gene REV3, which encodes the catalytic subunit of DNA polymerase zeta (polzeta). Characterization of the upr-1 mutant indicated that the UPR1 protein plays a role in DNA repair and mutagenesis. To help understand the mechanisms of mutagenic DNA repair in the N. crassa more extensively, we identified N. crassa homologs of yeast REV1 and REV7 and obtained mutants ncrev1 or ncrev7, which had similar phenotypes to the upr-1 mutant. Mutant carrying ncrev7 was more sensitive to UV and 4NQO, and slightly sensitive to MMS than the wild-type. The sensitivity to UV and MMS of the ncrev1 mutant was moderately higher than that of the wild-type, but the sensitivity to 4NQO of the mutant was similar to that of the wild-type. In reversion assay using testers with base substitution or frameshift mutation at the ad-3A locus, each of ncrev1 and ncrev7 mutants showed lower induced-mutability than the wild-type. Expression of ncrev1 and ncrev7 was found to be UV-inducible like the case of upr-1. Genetic analyses showed that the ncrev7 was identical to mus-26, which belongs to the upr-1 epistasis group, and that the ncrev1 was a newly identified DNA repair gene and designated as mus-42. Interestingly, all three mutants have a normal CPD photolyase gene, however, they showed a partial photoreactivation defect (PPD) phenotype, not completely defective but inefficient in photoreactivation. These results suggest that N. crassa REV homolog genes function in DNA repair and UV mutagenesis through the bypass of (6-4) photoproducts. 相似文献
984.
985.
Arabinogalactan proteins (AGPs) are abundant plant cell-surface proteoglycans widely distributed in plant species. Crossed electrophoresis patterns of AGPs isolated from cultured cells before and after protonemata development differed, indicating that AGPs are involved in protonemata differentiation and development. Moreover, the addition of β-glucosyl Yariv reagent (βglcY), which binds specifically to AGPs, inhibits protonemata differentiation in cells of the liverwort Marchantia polymorpha L. cultured in protonemata-inducing medium. Transmission electron microscopic examination revealed that βglcY caused conspicuous disorder at the cell surface and the accumulation of abnormal structures between the plasma membrane and the cell wall. These results suggest that AGPs/βglcY complexes caused disturbances at the cell surface and inhibited cell-wall synthesis required for protonemata differentiation. Our results indicate that AGPs play a significant role in cell-wall synthesis during the protonemata-differentiation process of M. polymorpha. 相似文献
986.
Deletion of Atf6α impairs astroglial activation and enhances neuronal death following brain ischemia in mice 下载免费PDF全文
987.
988.
Takai Y Matikainen T Jurisicova A Kim MR Trbovich AM Fujita E Nakagawa T Lemmers B Flavell RA Hakem R Momoi T Yuan J Tilly JL Perez GI 《Apoptosis : an international journal on programmed cell death》2007,12(4):791-800
Previously, we analyzed mice lacking either caspase-2 or caspase-3 and documented a role for caspase-2 in developmental and
chemotherapy-induced apoptosis of oocytes. Those data also revealed dispensability of caspase-3, although we found this caspase
critical for ovarian granulosa cell death. Because of the mutual interdependence of germ cells and granulosa cells, herein
we generated caspase-2 and -3 double-mutant (DKO) mice to evaluate how these two caspases functionally relate to each other
in orchestrating oocyte apoptosis. No difference was observed in the rate of spontaneous oocyte apoptosis between DKO and
wildtype (WT) females. In contrast, the oocytes from DKO females were more susceptible to apoptosis induced by DNA damaging
agents, compared with oocytes from WT females. This increased sensitivity to death of DKO oocytes appears to be a specific
response to DNA damage, and it was associated with a compensatory upregulation of caspase-12. Interestingly, DKO oocytes were
more resistant to apoptosis induced by methotrexate (MTX) than WT oocytes. These results revealed that in female germ cells,
insults that directly interfere with their metabolic status (e.g. MTX) require caspase-2 and caspase-3 as obligatory executioners
of the ensuing cell death cascade. However, when DNA damage is involved, and in the absence of caspase-2 and -3, caspase-12
becomes upregulated and mediates apoptosis in oocytes.
Takai and Matikainen contributed equally to this work. 相似文献
989.
Kouroku Y Fujita E Tanida I Ueno T Isoai A Kumagai H Ogawa S Kaufman RJ Kominami E Momoi T 《Cell death and differentiation》2007,14(2):230-239
Expanded polyglutamine 72 repeat (polyQ72) aggregates induce endoplasmic reticulum (ER) stress-mediated cell death with caspase-12 activation and vesicular formation (autophagy). We examined this relationship and the molecular mechanism of autophagy formation. Rapamycin, a stimulator of autophagy, inhibited the polyQ72-induced cell death with caspase-12 activation. PolyQ72, but not polyQ11, stimulated Atg5-Atg12-Atg16 complex-dependent microtubule-associated protein 1 (MAP1) light chain 3 (LC3) conversion from LC3-I to -II, which plays a key role in autophagy. The eucaryotic translation initiation factor 2 alpha (eIF2alpha) A/A mutation, a knock-in to replace a phosphorylatable Ser51 with Ala51, and dominant-negative PERK inhibited polyQ72-induced LC3 conversion. PolyQ72 as well as ER stress stimulators upregulated Atg12 mRNA and proteins via eIF2alpha phosphorylation. Furthermore, Atg5 deficiency as well as the eIF2alpha A/A mutation increased the number of cells showing polyQ72 aggregates and polyQ72-induced caspase-12 activation. Thus, autophagy formation is a cellular defense mechanism against polyQ72-induced ER-stress-mediated cell death by degrading polyQ72 aggregates, with PERK/eIF2alpha phosphorylation being involved in polyQ72-induced LC3 conversion. 相似文献
990.
Kimura T Nguyen JT Maegawa H Nishiyama K Arii Y Matsui Y Hayashi Y Kiso Y 《Bioorganic & medicinal chemistry letters》2007,17(12):3276-3280
The human T-cell leukemia virus type 1 (HTLV-I) causes adult T-cell leukemia and several severe chronic diseases. HTLV-I protease (PR) inhibition stops the propagation of the virus. Herein, truncation studies were performed on potent octapeptidic HTLV-I PR inhibitor KNI-10161 to derive small hexapeptide KNI-10127 with some loss in activity. After performing residue-substitution studies on compound KNI-10127, HTLV-I PR inhibitory activity was recovered in inhibitor KNI-10166. 相似文献