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911.
Gu Yaping Zou Yunzeng Aikawa Ryuichi Hayashi Doubun Kudoh Sumiyo Yamauchi Toshimasa Uozumi Hiroki Zhu Weidong Kadowaki Takashi Yazaki Yoshio Komuro Issei 《Molecular and cellular biochemistry》2001,223(1-2):35-46
Growth hormone (GH) has been reported to be useful to treat heart failure. To elucidate whether GH has direct beneficial effects on the heart, we examined effects of GH on oxidative stress-induced apoptosis in cardiac myocytes. TUNEL staining and DNA ladder analysis revealed that hydrogen peroxide (H2O2)-induced apoptosis of cardiomyocytes was significantly suppressed by the pretreatment with GH. GH strongly activated extracellular signal-regulated kinases (ERKs) in cardiac myocytes and the cardioprotective effect of GH was abolished by inhibition of ERKs. Overexpression of dominant negative mutant Ras suppressed GH-stimulated ERK activation. Overexpression of Csk that inactivates Src family tyrosine kinases also inhibited ERK activation evoked by GH. A broad-spectrum inhibitor of protein tyrosine kinases (PTKs), genistein, strongly suppressed GH-induced ERK activation and the cardioprotective effect of GH against apoptotic cell death. GH induced tyrosine phosphorylation of EGF receptor and JAK2 in cardiac myocytes, and an EGF receptor inhibitor tyrphostin AG1478 and a JAK2 inhibitor tyrphostin B42 completely inhibited GH-induced ERK activation. Tyrphostin B42 also suppressed the phosphorylation of EGF receptor stimulated by GH. These findings suggest that GH has a direct protective effect on cardiac myocytes against apoptosis and that the effect of GH is attributed at least in part to the activation of ERKs through Ras and PTKs including JAK2, Src, and EGF receptor tyrosine kinase. 相似文献
912.
Pablo Perez Goodwyn Yasunori Maezono Hiroki Takamatsu Kenji Fujisaki 《Hydrobiologia》2009,630(1):219-229
Using high-speed video recordings, we carried out an analysis of the locomotion gaits of the following aquatic Heteroptera:
coral treaders Hermatobates
weddi (Hermatobatidae), sea striders Halovelia septentrionalis (Veliidae), and water striders Metrocoris histrio (Gerridae), in the Island of Amami Oshima, Kagoshima Prefecture, Japan. Most insects use an alternating double tripod gait
for walking, whereas species of Gerridae and some Veliidae use a synchronous rowing gait. We found that H. weddi used a peculiar locomotion gait, a modification of the double tripod gait. In this special gait, two alternating dipods (mid
and hind legs) are used, while the forelegs remained inactive. Contralateral mid and hind stroked simultaneously. The mid
leg recovered immediately after the stroke; however, the hind leg was delayed and remained extended after the stroke. Next,
the following bipod stroked, and when that mid leg finished the stroke, both ipsilateral mid and hind (the one which did not
recover after the stroke) legs recovered together. Turning is also unique in H. weddi because the body axis rotation and the course turning (deflection) were clearly separated in two phases. We compared the
kinematics of H. weddi pattern with the synchronous rowing pattern found in H. septentrionalis and M. histrio and discussed some biomechanical consequences. We also analyzed phylogenetic implications of this gait, and we posit that
the modified double dipod gait is a uniquely derived character of the family Hermatobatidae. The synchronous rowing gait would
be an autapomorphy for the clade Gerridae + Veliidae. The modified thorax, with the meso and metacoxae horizontally directed,
would be a synapomorphy for the superfamily Gerroidea (Hermatobatidae, Gerridae, and Veliidae).
Handling editor: Koen Martens 相似文献
913.
Zen��ichiro Kawabata Toshifumi Minamoto Mie N. Honjo Kimiko Uchii Hiroki Yamanaka Alata A. Suzuki Yukihiro Kohmatsu Kota Asano Tomoaki Itayama Tomoaki Ichijo Koji Omori Noboru Okuda Masayuki Kakehashi Masao Nasu Kazuaki Matsui Masatomi Matsuoka Hainan Kong Teruhiko Takahara Deyi Wu Ryuji Yonekura 《Ecological Research》2011,26(6):1011-1016
To predict outbreaks of infectious disease and to prevent epidemics, it is essential not only to conduct pathological studies but also to understand the interactions between the environment, pathogen, host and humans that cause and spread infectious diseases. Outbreaks of mass mortality in carp caused by Cyprinid herpesvirus 3 (CyHV-3), formerly known as koi herpesvirus (KHV), disease have occurred worldwide since the late 1990s. We proposed an environment?CKHV?Ccarp?Chuman linkage as a conceptual model for ??environmental diseases?? and specify research subjects that might be necessary to construct and shape this linkage. 相似文献
914.
Host range factor 1 (HRF-1) of Lymantria dispar multinucleocapsid nucleopolyhedrovirus promotes Autographa californica MNPV replication in nonpermissive Ld652Y cells derived from L. dispar. Here we demonstrate that restricted Hyphantria cunea NPV replication in Ld652Y cells was not due to apoptosis but was likely due to global protein synthesis arrest that could be restored by HRF-1. Our data also showed that HRF-1 promoted the production of progeny virions for two other baculoviruses, Bombyx mori NPV and Spodoptera exigua MNPV, whose replication in Ld652Y cells is limited to replication of viral DNA without successful production of infectious progeny virions. Thus, HRF-1 is an essential viral factor required for productive infection of NPVs in Ld652Y cells. 相似文献
915.
Yoshiomi Kobayashi Yohei Okada Go Itakura Hiroki Iwai Soraya Nishimura Akimasa Yasuda Satoshi Nori Keigo Hikishima Tsunehiko Konomi Kanehiro Fujiyoshi Osahiko Tsuji Yoshiaki Toyama Shinya Yamanaka Masaya Nakamura Hideyuki Okano 《PloS one》2012,7(12)
Murine and human iPSC-NS/PCs (induced pluripotent stem cell-derived neural stem/progenitor cells) promote functional recovery following transplantation into the injured spinal cord in rodents. However, for clinical applicability, it is critical to obtain proof of the concept regarding the efficacy of grafted human iPSC-NS/PCs (hiPSC-NS/PCs) for the repair of spinal cord injury (SCI) in a non-human primate model. This study used a pre-evaluated “safe” hiPSC-NS/PC clone and an adult common marmoset (Callithrix jacchus) model of contusive SCI. SCI was induced at the fifth cervical level (C5), followed by transplantation of hiPSC-NS/PCs at 9 days after injury. Behavioral analyses were performed from the time of the initial injury until 12 weeks after SCI. Grafted hiPSC-NS/PCs survived and differentiated into all three neural lineages. Furthermore, transplantation of hiPSC-NS/PCs enhanced axonal sparing/regrowth and angiogenesis, and prevented the demyelination after SCI compared with that in vehicle control animals. Notably, no tumor formation occurred for at least 12 weeks after transplantation. Quantitative RT-PCR showed that mRNA expression levels of human neurotrophic factors were significantly higher in cultured hiPSC-NS/PCs than in human dermal fibroblasts (hDFs). Finally, behavioral tests showed that hiPSC-NS/PCs promoted functional recovery after SCI in the common marmoset. Taken together, these results indicate that pre-evaluated safe hiPSC-NS/PCs are a potential source of cells for the treatment of SCI in the clinic. 相似文献
916.
1. | Some properties of the open-tipped, uninsulated, pH-sensitive glass microelectrode were examined in several electrical experiments. |
2. | Based on these observations, technical and theoretical problems were considered for application to the pH measurement in small cells. |
3. | The intracellular pH, (pH)i, of the epithelial cell in rat duodenum measured was approximately 7.0. A reduction in (pH)i was apparent (about 0.3) with the addition of 20 mM-glucose to the bathing fluid. |
4. | It was concluded, that with certain limitations such uninsulated, open-tipped microelectrodes may be successfully utilized for intracellular pH measurements. |
917.
Yoshiki Nomura Hiroki Tanabe Kentaro Moriichi Satomi Igawa Katsuyoshi Ando Nobuhiro Ueno Shin Kashima Motoya Tominaga Takuma Goto Yuhei Inaba Takahiro Ito Akemi Ishida-Yamamoto Mikihiro Fujiya Yutaka Kohgo 《Biochemical and biophysical research communications》2013
Barrett’s esophagus (BE) is metaplastic columnar epithelium converted from normal squamous epithelia in the distal esophagus that is thought to be a precancerous lesion of esophageal adenocarcinoma. BE is attributed to gastroesophageal reflux disease (GERD), and therefore gastric acid or bile acids are thought to be factors that cause epithelial cell damage and inflammation in the gastro-esophageal junction. The decrease of adherent junction molecules, E-cadherin has been reported to be associated with the progression of the Barrett’s carcinoma, but the initiation of BE is not sufficiently understood. BE is characterized by the presence of goblet cells and occasionally Paneth cells are observed at the base of the crypts. The Paneth cells possess dense granules, in which human antimicrobial peptide human defensin-5 (HD-5) are stored and secreted out of the cells. This study determined the roles of HD-5 produced from metaplastic Paneth cells against adjacent to squamous cells in the gastro-esophageal junction. A human squamous cell line Het-1A, was incubated with the synthetic HD-5 peptide as a model of squamous cell in the gastro-esophageal junctions, and alterations of E-cadherin were investigated. Immunocytochemistry, flowcytometry, and Western blotting showed that the expression of E-cadherin protein was decreased. And a partial recovery from the decrease was observed by treatment with a CD10/neprilysin inhibitor (thiorphan). In conclusion, E-cadherin expression in squamous cells was reduced by HD-5 using in vitro experiments. In gastro-esophageal junction, HD-5 produced from metaplastic Paneth cells may therefore accelerate the initiation of BE. 相似文献
918.
Tanabe H Ayabe T Maemoto A Ishikawa C Inaba Y Sato R Moriichi K Okamoto K Watari J Kono T Ashida T Kohgo Y 《Biochemical and biophysical research communications》2007,358(1):349-355
alpha-Defensin is an antimicrobial peptide which plays an important role in innate immunity. Human defensin (HD)-5 is stored in the Paneth cells of the small intestine as a pro-form and is cleaved by trypsin, which is co-secreted from the Paneth cell granules. The mature HD-5 is protected from further digestion by the proteolysis enzyme. We generated both recombinant HD-5 and proHD-5, and the reduced form of each peptide in order to determine their physiological roles of the disulfide bonds. The reduced proHD-5 attenuated the bactericidal activity and the stability against the trypsin digestion. Human defensin was protected from the enzymatic degradation by disulfide bridges. We further purified the HD-5 with a disulfide variation in the small intestine of Crohn's disease patients. The HD-5 was sensitive to the trypsin treatment. These observations evidently predict that a defensin deficiency may be caused by a disulfide disorder in the disease. 相似文献
919.
Fumiko Sekiguchi Yosuke Miyamoto Daiki Kanaoka Hiroki Ide Shigeru Yoshida Tsuyako Ohkubo Atsufumi Kawabata 《Biochemical and biophysical research communications》2014
Hydrogen sulfide (H2S), a gasotransmitter, is formed from l-cysteine by multiple enzymes including cystathionine-γ-lyase (CSE). We have shown that an H2S donor, NaHS, causes hyperalgesia in rodents, an effect inhibited by knockdown of Cav3.2 T-type Ca2+ channels (T-channels), and that NaHS facilitates T-channel-dependent currents (T-currents) in NG108-15 cells that naturally express Cav3.2. In the present study, we asked if endogenous and exogenous H2S participates in regulation of the channel functions in Cav3.2-transfected HEK293 (Cav3.2-HEK293) cells. dl-Propargylglycine (PPG), a CSE inhibitor, significantly decreased T-currents in Cav3.2-HEK293 cells, but not in NG108-15 cells. NaHS at 1.5 mM did not affect T-currents in Cav3.2-HEK293 cells, but enhanced T-currents in NG108-15 cells. In the presence of PPG, NaHS at 1.5 mM, but not 0.1–0.3 mM, increased T-currents in Cav3.2-HEK293 cells. Similarly, Na2S, another H2S donor, at 0.1–0.3 mM significantly increased T-currents in the presence, but not absence, of PPG in Cav3.2-HEK293 cells. Expression of CSE was detected at protein and mRNA levels in HEK293 cells. Intraplantar administration of Na2S, like NaHS, caused mechanical hyperalgesia, an effect blocked by NNC 55-0396, a T-channel inhibitor. The in vivo potency of Na2S was higher than NaHS. These results suggest that the function of Cav3.2 T-channels is tonically enhanced by endogenous H2S synthesized by CSE in Cav3.2-HEK293 cells, and that exogenous H2S is capable of enhancing Cav3.2 function when endogenous H2S production by CSE is inhibited. In addition, Na2S is considered a more potent H2S donor than NaHS in vitro as well as in vivo. 相似文献
920.
Hiromasa Saitoh Shizuko Fujisawa Chikako Mitsuoka Akiko Ito Akiko Hirabuchi Kyoko Ikeda Hiroki Irieda Kae Yoshino Kentaro Yoshida Hideo Matsumura Yukio Tosa Joe Win Sophien Kamoun Yoshitaka Takano Ryohei Terauchi 《PLoS pathogens》2012,8(5)
To search for virulence effector genes of the rice blast fungus, Magnaporthe oryzae, we carried out a large-scale targeted disruption of genes for 78 putative secreted proteins that are expressed during the early stages of infection of M. oryzae. Disruption of the majority of genes did not affect growth, conidiation, or pathogenicity of M. oryzae. One exception was the gene MC69. The mc69 mutant showed a severe reduction in blast symptoms on rice and barley, indicating the importance of MC69 for pathogenicity of M. oryzae. The mc69 mutant did not exhibit changes in saprophytic growth and conidiation. Microscopic analysis of infection behavior in the mc69 mutant revealed that MC69 is dispensable for appressorium formation. However, mc69 mutant failed to develop invasive hyphae after appressorium formation in rice leaf sheath, indicating a critical role of MC69 in interaction with host plants. MC69 encodes a hypothetical 54 amino acids protein with a signal peptide. Live-cell imaging suggested that fluorescently labeled MC69 was not translocated into rice cytoplasm. Site-directed mutagenesis of two conserved cysteine residues (Cys36 and Cys46) in the mature MC69 impaired function of MC69 without affecting its secretion, suggesting the importance of the disulfide bond in MC69 pathogenicity function. Furthermore, deletion of the MC69 orthologous gene reduced pathogenicity of the cucumber anthracnose fungus Colletotrichum orbiculare on both cucumber and Nicotiana benthamiana leaves. We conclude that MC69 is a secreted pathogenicity protein commonly required for infection of two different plant pathogenic fungi, M. oryzae and C. orbiculare pathogenic on monocot and dicot plants, respectively. 相似文献