記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2337/db10-0655

記述言語：英語   掲載種別：研究論文（学術雑誌）  

OBJECTIVE - Chronic hypoxia has been recognized as a key regulator in renal tubulointerstitial fibrosis, as seen in diabetic nephropathy, which is associated with the activation of hypoxia-inducible factor (HIF)-1α. We assess here the effects of the biguanide, metformin, on the expression of HIF-1α in diabetic nephropathy using renal proximal tubular cells and type 2 diabetic rats. RESEARCH DESIGN AND METHODS - We explored the effects of metformin on the expression of HIF-1α using human renal proximal tubular epithelial cells (HRPTECs). Male Zucker diabetic fatty (ZDF
Gmi-fa/fa) rats were treated from 9 to 39 weeks with metformin (250 mg · kg-1 · day-1) or insulin. RESULTS - Metformin inhibited hypoxia-induced HIF-1α accumulation and the expression of HIF-1-targeted genes in HRPTECs. Although metformin activated the downstream pathways of AMP-activated protein kinase (AMPK), neither the AMPK activator, AICAR, nor the mTOR inhibitor, rapamycin, suppressed hypoxia-induced HIF-1α expression. In addition, knockdown of AMPK-α did not abolish the inhibitory effects of metformin on HIF-1α expression. The proteasome inhibitor, MG-132, completely eradicated the suppression of hypoxia-induced HIF-1α accumulation by metformin. The inhibitors of mitochondrial respiration similarly suppressed hypoxia-induced HIF-1α expression. Metformin significantly decreased ATP production and oxygen consumption rates, which subsequently led to increased cellular oxygen tension. Finally, metformin, but not insulin, attenuated tubular HIF-1α expression and pimonidazole staining and ameliorated tubular injury in ZDF rats. CONCLUSIONS - Our data suggest that hypoxia-induced HIF-1α accumulation in diabetic nephropathy could be suppressed by the antidiabetes drug, metformin, through the repression of oxygen consumption. © 2011 by the American Diabetes Association.

DOI： 10.2337/db10-0655

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1387/ijdb.072543ta

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The fish egg is surrounded by a thick envelope called the chorion. The fertilizing spermatozoon enters the egg through a canal-like structure in the chorion, the micropyle. Examination of micropyle at fertilization is difficult if eggs are large and have no distinct landmarks surrounding the micropyle, or if they are positively buoyant in water. Eggs of many commercially important fishes (e.g., flounder, sea bream and eel) are buoyant in water or only slightly adhere to solid objects (e.g., sands, rock and water plants), which makes observation of spermatozoa at fertilization difficult. Here, we report that such eggs can be firmly attached to plastic and glass dishes that have been previously coated with poly-L-lysine. These adhering eggs can be fertilized and develop normally on the dishes. Observations of micropyles of three fish species, before and after sperm entry are presented. © UBC Press.

DOI： 10.1387/ijdb.072543ta

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1679/aohc.67.57

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Secretogranin HI (SgIII), a member of the granin protein family, is expressed specifically in neuronal and endocrine cells. To examine the precise localization of SgIII in the endocrine pancreas, pancreatic tissues of rats were analyzed immunocytochemically with a polyclonal anti-serum raised against rat SgIII. By light microscopy of semithin sections, the immunoreactivity for SgIII was readily detected in pancreatic A- and B-cells, faintly so in D-cells, and not at all in the exocrine pancreas. By immunoelectron microscopy, immunogold particles indicative of SgIII were observed in the peripheral regions of secretory granules, and universally in the pancreatic endocrine cells. Morphometrical analyses indicated that SgIII is most preferentially localized in the periphery of the secretory granule among granins. These findings suggest that SgIII is closely associated with the secretory granule membrane, serving to anchor the aggregates of other soluble constituents to the membrane.

DOI： 10.1679/aohc.67.57

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Histochemical Society Inc.  

Secretogranin III (SgIII) is one of the acidic secretory proteins, designated as granins, which are specifically expressed in neuronal and endocrine cells. To clarify its precise distribution in the anterior lobe of the rat pituitary gland, we raised a polyclonal antiserum against rat SgIII for immunocytochemical analyses. By immunohistochemistry using semithin sections, positive signals for SgIII were detected intensely in mammotropes and thyrotropes, moderately in gonadotropes and corticotropes, but not in somatotropes. The distribution pattern of SgIII in the pituitary gland was similar to that of chromogranin B (CgB), also of the granin protein family, suggesting that the expressions of these two granins are regulated by common mechanisms. The localization of SgIII in endocrine cells was confirmed by immunoelectron microscopy. In particular, secretory granules of mammotropes and thyrotropes were densely and preferentially co-labeled for SgIII and CgB in their periphery. Moreover, positive signals for SgIII were occasionally found in cells containing both prolactin and TSH in secretory granules. These lines of evidence suggest that SgIII and CgB are closely associated with the secretory granule membrane and that this membrane association might contribute to gathering and anchoring of other soluble constituents to the secretory granule membrane.

DOI： 10.1177/002215540305100211

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Localization of mRNAs for four membrane-bound guanylyl cyclases (membrane GCs
OIGC3, OIGC4, OIGC5, and OIGC-R2), three soluble guanylyl cyclase subunits (soluble GC
OIGCS-α1, OIGCS-α2, and OIGCS-β1), neuronal nitric oxide synthase (nNOS), and cGMP-dependent protein kinase I (cGK I) was examined in the embryonic and adult retinas of the medaka fish Oryzias latipes by in situ hybridization. All of the membrane GC mRNAs were detected in the photoreceptor cells of the adult and embryonic retinas, but in different parts
the OIGC3 and OIGC5 mRNAs were expressed in the proximal part and the OIGC4 and OIGC-R2 mRNAs were expressed in the outer nuclear layer. The mRNA for nNOS was expressed in a scattered fashion on the inner side of the inner nuclear layer in the adult and embryonic retinas. The mRNAs (OIGCS-α2 and OIGCS-β1) of two soluble GC subunits (α2 and β1) were expressed mainly in the inner nuclear layer and the ganglion cell layer of the embryonic retina while the mRNAs of the soluble GC α1 subunit and cGK I were not detected in either the adult or embryonic retina. These results suggest that NO itself and/or the cGMP generated by soluble GC (α2/β1 heterodimer) play a novel role in the neuronal signaling and neuronal development in the medaka fish embryonic retina in addition to the role played by phototransduction through membrane GCs in the adult and embryonic retinas.

DOI： 10.2108/zsj.20.133

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：ZOOLOGICAL SOC JAPAN  

To better understand the nitric oxide (NO) / cyclic GMP (cGMP) signaling pathway during embryogenesis, we examined the spatial and temporal expression pattern of the genes for neuronal nitric oxide synthase (nNOS), soluble guanylyl cyclase (soluble GC) subunit (OIGCS-alpha(1), OIGCS-alpha(2), and OIGCS-beta(1)), and cGMP-dependent protein kinase (cGK) I and II (cGK I and cGK II) in the medaka fish embryos. OIGCS-beta(1) and nNOS were expressed maternally and OIGCS-alpha(1), OIGCS-alpha(2), cGK I, and cGK II were expressed zygotically. The zygotic expression of OIGCS-alpha(1) and cGK / was detected at stage 19, while that of OIGCS-a2 was detected at stage 16. Whole-mount in situ hybridization showed that the expression of nNOS or cGK / was localized in tail bud, otic vesicles, thyroid, and brain ventricle, or in thymus, gill arch, and olfactory pits, respectively, and that of OIGCS-alpha(1), OIGCS-alpha(2), or OIGCS-beta(1) was dim and dispersed throughout the embryos. To clarify the "role of the NO/cGMP signaling pathway in embryogenesis, we examined the influences of morpholino antisense oligonucleotide of the soluble GC subunit gene (alpha(1)-MO, alpha(2)-MO or beta(1)-MO) on development of medaka fish embryos. Embryos injected with alpha(1)-MO or alpha(2)-MO mainly exhibited abnormalities in the central nervous system, including defects in the formation of forebrain, eye, and otic vesicles. alpha(2)-MO injection caused cell death at the tail bud of the embryos at stage 22, and beta(1)-MO injection inhibited the development of the embryos at late blastula. These results suggest that the NO/cGMP signaling pathway plays critical roles in early embryogenesis.

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記述言語：英語   出版者・発行元：ELSEVIER SCIENCE BV  

Melatonin is an indoleamine hormone that is synthesized from tryptophan via 5-hydroxytryptophan, serotonin and N-acetylserotonin in the vertebrate pineal gland. Many chromatographic and non-chromatographic techniques have been developed and improved for the determination and measurement of melatonin and its related indoleamines. At present, gas chromatography with mass spectrometry and reversed-phase high-performance liquid chromatography with fluorescence or electrochemical detection are widely used for indoleamine determinations in the pineal gland. This review will deal with methods for the separation and determination of the melatonin and its related indoleamines. (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0378-4347(00)00064-5

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記述言語：英語   出版者・発行元：ACADEMIC PRESS INC  

Day- and nighttime contents of pineal melatonin and other indoleamines were measured in the Chinese hamster, Cricetulus griseus. The hamsters were inbred in our colony and kept in LD 14:10. Absolute levels of pineal melatonin and N-acetylserotonin contents were extremely low, but showed a significant circadian rhythm with a minor peak during the light period. Pineal hydroxytryptophan and serotonin (5HT) contents were also found to be higher in the light period. The activity of N-acetyltransferase in the pineal was higher in the light period than in the dark period, whereas there was no difference in hydroxyindole-O-methyltransferase activity between the light and dark periods. The uptake level of tryptophan into the pineal gland was higher in the light period than in the dark period. These results suggest that the 5HT synthesis pathway and/or tryptophan uptake may be involved in forming the circadian rhythm of 5HT content in the Chinese hamster pineal gland. (C) 1998 Academic Press.

DOI： 10.1006/gcen.1997.7014

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記述言語：英語   出版者・発行元：ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS  

Zonadhesin is a recently discovered sperm membrane protein that binds to the extracellular matrix of the egg in a species-specific manner. The gene for zonadhesin maps to chromosome 5 in the mouse (Zan) and to chromosome 7 in the human (ZAN) in a position near the gene for the egg extracellular matrix protein ZP3. (C) 1997 Academic Press.

DOI： 10.1006/geno.1997.4620

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記述言語：英語   出版者・発行元：ZOOLOGICAL SOC JAPAN  

Intact sea urchin spermatozoa were successfully biotinylated with NHS-LC-Biotin and the biotinylated spermatozoa retained the viability. Analysis of the membrane prepared from the biotinylated spermatozoa of the sea urchin Hemicentrotus pulcherrimus by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that several proteins such as wheat-germ agglutinin (WGA)-binding protein (220 kDa), guanylyl cyclase (131 kDa), sperm-activating peptide-I (SAP-I)-crosslinking protein (71 kDa), GPI-anchored protein (63 kDa) and functionally unknown proteins (50 kDa and 30 kDa) were specifically biotinylated. Experiments using spermatozoa of sea urchins, Anthocidaris crassispina and Clypeasfer japonicus showed that several proteins similar to those of H. pulcherrimus spermatozoa were also labeled with NHS-LC-Biotin.
Fucose sulfate glycoconjugate (FSG) isolated from the jelly coat of H. pulcherrimus was mixed with solubilized biotinylated sperm membrane proteins of H. pulcherrimus, A. crassispina or C. japonicus and then subjected to gel filtration chromatography on a Sepharose 2B column, indicating that only two biotinylated H. pulcherrimus sperm proteins were coeluted with H. pulcherrimus FSG.

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記述言語：英語   出版者・発行元：ELSEVIER SCIENCE BV  

A simple and simultaneous determination of melatonin and its precursors, serotonin (5-HT) and N-acetylserotonin, was achieved by reversed-phase high-performance liquid chromatography with electrochemical detection. The addition of an ion-paring agent, sodium 1-octanesulfonate, to the chromatographic mobile phase caused an increase of the retention time of 5-HT, and resulted in the successful simultaneous resolution of these three indoleamines. This method was used to quantitate these indoleamines in the pineal gland of juvenile golden hamsters.

DOI： 10.1016/0378-4347(95)00345-2

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DOI： 10.1006/sedb.1994.1029

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記述言語：英語   出版者・発行元：Zoological Society of Japan  

We identified two phosphorylatable proteins (33 kDa and 48 kDa) in crude extractes of spermatozoa from the sea urchin, Hemicentrotus pulcherrimus. While the 33 kDa protein was phosphorylated in 100 mM Mg^<2+>-containing medium with cAMP or cGMP, phosphorylation of the 48 kDa protein occurred irrespective of the Mg^<2+>-concentration if it was more than 10 mM. Physiological concentration if it was more than 10 mM. Physiological concentrations of cAMP or cGMP triggered dephosphorylation of the [^<32>P]-phosphorylated 48 kDa protein in a concentration dependent manner. The dephosphorylation of 48 kDa protein was inhibited with calyculin A or okadaic acid. The 48 kDa protein was associated with a 39 kDa protein to form a larger oligomer with about 400 kDa. The purified 400 kDa protein showed cyclic nucleotide-dependent histone kinase activity. The histone kinase activity shifted from 400 kDa to 39 kDa on a Superose 6 HR in the presence of 5×10^<-6>M cAMP. Phosphorylation of the 48 kDa protein in the purified 400 kDa protein required only Mg[^<32>P]ATP. A photoaffinity cAMP analogue, 8-N_3-[^<32>P]cAMP, was incorporated into the 48 kDa protein. These results suggest that the 48 kDa protein which is a reguratory subunit of the histone kinase is autophosphorylated, and binding of cAMP to the phosphorylated 48 kDa subunit of the kinase results in dissociation of the 48 kDa subunit(s) from the 39 kDa subunit(s) to allow the 48 kDa subunit accessible to a protein phosphatase.

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10860784

記述言語：英語   出版者・発行元：BLACKWELL SCIENCE  

DOI： 10.1111/j.1440-169X.1992.00403.x

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記述言語：英語   出版者・発行元：BLACKWELL SCIENCE  

DOI： 10.1111/j.1440-169X.1992.tb00004.x

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記述言語：英語   出版者・発行元：Zoological Society of Japan  

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その他リンク： http://id.nii.ac.jp/1141/00031842/

DOI： 10.1111/j.1440-169X.1992.tb00005.x

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記述言語：英語   出版者・発行元：JAPAN BIOCHEMICAL SOC  

Sea urchin spermatozoa obtain energy for movement through oxidation of endogenous phospholipids, particularly phosphatidylcholine (PC). This study was undertaken to determine the localization of PC available for utilization in energy metabolism in spermatozoa of the sea urchin, Hemicentrotus pulcherrimus. Following incubation with sea water, the PC content in sperm heads decreased significantly, while that in sperm tails did not change. PC was abundant in sperm heads, particularly the midpieces. PC composed of unsaturated fatty acids was consumed to a greater extent during incubation than that consisting of saturated fatty acids. Analysis by gas-liquid chromatography indicated most of fatty acid moieties in the midpieces PC to be unsaturated. Phospholipase A2 activity was also distributed in sperm heads, particularly the midpieces. It thus appears that PC as a substrate for energy metabolism is located in the midpieces of sea urchin spermatozoa.

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記述言語：英語  

Sperm‐activating peptide analogues, GYGG‐SAP‐I (Gly‐Tyr‐Gly‐Gly‐Gly‐Phe‐Asp‐Leu‐Asn‐Gly‐Gly‐Gly‐Val‐Gly) and GYGG‐SAP‐IIB (Gly‐Tyr‐Gly‐Gly‐Lys‐Leu‐Cys‐Pro‐Gly‐Gly‐Asn‐Cys‐Val) which exibit almost the same respiration‐stimulating activity as the respective original peptide were chemically synthesized, radiolabeled with Na1251, and used for experiments of binding and cross‐linking to Hemicentrotus pulcherrimus or Glyptocidaris crenularis spermatozoa. In competitive binding, SAP‐I caused 50% decrease in 125l‐GYGG‐SAP‐l binding to intact spermatozoa, sperm heads and sperm tails of H. pulcherrimus at the concentrations of 282 nM, 3 nM and 141 nM, respectively. The incubations of H. pulcherrimus sperm tails with 125l‐GYGG‐SAP‐I and the chemical cross‐linking reagent, disuccinimidyl suberate, resulted in the appearance of two radiolabeled bands with apparent molecular masses of 71 kDa and 63 kDa (determined by sodium dodecyl sulfate‐gel electrophoresis under reducing conditions). 125l‐GYGG‐SAP‐IIB bound almost equally to sperm heads and sperm tails of G. crenularis, and was cross‐linked to 172 kDa, 62 kDa and 58 kDa proteins in sperm heads, and 157 kDa and 62 kDa proteins in sperm tails with disuccinimidyl suberate. Copyright © 1991, Wiley Blackwell. All rights reserved

DOI： 10.1111/j.1440-169X.1991.00067.x

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記述言語：英語   出版者・発行元：ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS  

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記述言語：英語   出版者・発行元：ELSEVIER SCIENCE BV  

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記述言語：英語   出版者・発行元：PERGAMON-ELSEVIER SCIENCE LTD  

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記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）   出版者・発行元：BLACKWELL SCIENCE  

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開催年月日： 2022年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：東京  

開催年月日： 2022年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催年月日： 2010年12月

記述言語：英語   会議種別：ポスター発表  

開催地：Philadelphia, USA  

開催年月日： 2008年5月

記述言語：英語   会議種別：ポスター発表  

開催地：Kona, USA