Archives of Histology and Cytology
Online ISSN : 1349-1717
Print ISSN : 0914-9465
ISSN-L : 0914-9465
74 巻, 1 号
選択された号の論文の6件中1~6を表示しています
Original articles
  • Ken Iseki, Seita Hagino , Tetsuji Mori, Yuxiang Zhang, Nobuko Sakai , ...
    2013 年 74 巻 1 号 p. 1-7
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    The Olig gene family encodes basic helixloop-helix (bHLH) transcription factors and plays a critical role in oligodendrogenesis during development. We examined whether the Olig genes are involved in pathological conditions such as the injured brain or spinal cord by in situ hybridization. Olig1 mRNA was detected in cells surrounding necrotic tissue. The signal intensity of Olig1 mRNA gradually increased 2 to 7 days and decreased by 14 days after injury. Olig2 mRNA was expressed in a similar pattern and was colocalized with Olig1 mRNA. Similar results were obtained for the expression of Olig1 and Olig2 mRNAs in spinal cord injury. When we compared the mRNA expression pattern of Olig1 with that of NG2 proteoglycan and platelet-derived growth factor receptor α (PDGFRα), markers for oligodendrocyte precursor cells (OPCs), by double labeling in situ hybridization, Olig1 mRNA was co-localized with mRNAs for NG2 proteoglycan and PDGFRα 7 days after brain injury, suggesting that Olig mRNAs were expressed in OPCs. These findings suggest that the Olig transcription factors regulate differentiation of oligodendrocytes in the injured CNS as well as in the developing CNS.
  • Hirohide Hirohide Takahashi , Robert M. Henderson, J. Michael Edwardso ...
    2013 年 74 巻 1 号 p. 9-17
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    Synaptic vesicle fusion with the presynaptic plasma membrane is mediated by the soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins. Assembly of a complex between a vesicle-associated membrane protein, VAMP (a v-SNARE), in the vesicle membrane and a syntaxin 1A-SNAP-25 (t-SNAREs) heterodimer in the target presynaptic membrane drives fusion. Additionally, synaptotagmin acts as a Ca2+-sensitive and phosphatidylserine (PS)-dependent trigger protein to initiate fusion. To dissect out the interaction of synaptotagmin with the t-SNAREs, we used atomic force microscopy (AFM) in recognition imaging mode to study its binding to the syntaxin 1A-SNAP-25 complex integrated into lipid bilayers without PS. Using a synaptotagmin-functionalized AFM cantilever, we identified a Ca2+-independent binding signal between synaptotagmin and the syntaxin 1A-SNAP-25 complex at the single-molecule level. Within the nerve terminal, this Ca2+-independent interaction could potentially locate synaptotagmin close to the t-SNAREs in preparation for recognition of the incoming Ca2+ signal.
  • Yasunori Tamagawa, Tomoyuki Saino, Makoto Matsuura, Makoto Oikawa, Yoh ...
    2013 年 74 巻 1 号 p. 19-29
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    We reported previously that spironolactone (SPL) induced an increase in intracellular Ca2+ concentration ([Ca2+]i) in rat testicular arteriole smooth muscle cells. In the present study, we further investigated the mechanism of SPL-induced [Ca2+]i dynamics in rat arteriole smooth muscles. The increase in [Ca2+]i induced by SPL (300 μM) was markedly inhibited in extracellular Ca2+-free conditions and in the presence of diltiazem or gadolinium. In contrast, the phospholipase C inhibitor (U73122), did not affect the SPL-induced increase in [Ca2+]i, similar to what was observed for 2-aminoethoxydiphenyl borate (2- APB: an inhibitor of inositol triphosphate (IP3)dependent Ca2+ mobilization). Moreover, the protein kinase A (PKA) inhibitor H89 partially inhibited the SPL-induced increase in [Ca2+]i, whereas the protein kinase C (PKC) inhibitor GF109203X did not. Either suramin (a non-specific G protein antagonist) or NF449 (an inhibitor of the α-subunit of the stimulatory G protein G), partially blocked the SPL-induced increase in [Ca2+]i. Similarily, either mifepristone, a glucocorticoid-receptor antagonist, or flutamide, a non-steroidal antiandrogen drug, partially blocked the SPL-induced increase in [Ca2+]i. We suggest that the SPL-induced increase in [Ca2+]i in arterioles is mediated both by Ca2+ influx from the extracellular fluid and by Ca2+ mobilization from internal Ca2+ stores, with the former being dominant. We thus propose that SPL interacts with both extracellular (i.e., G-proteincoupled-type) and intracellular (e.g., glucocorticoid) receptors in rat testicular arterioles, which is followed by an increase in intracellular Ca2+ that causes smooth-muscle contraction.
  • Tomoko Komagamine, Kenjiro Matsuno , Yasuhiko Sakumoto, Hideo Takahash ...
    2013 年 74 巻 1 号 p. 31-40
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    Muscle spindles are known to be innervated by both sensory and motor nerve endings. Sensory nerves are mainly distributed in the equatorial regions of muscle spindles, while motors are distributed in the polar regions. To examine the ganglioside expression in sensory and motor nerve endings, we investigated the topographical difference in the distribution of GM1, GD1a, GQ1b and GD1b gangliosides in the muscle spindles of masseter, flexor carpi ulnaris and lumbar paraspinal muscles of adult rats. Whereas GM1, GD1a and GD1b are distributed widely in both the sensory and motor regions of muscle spindles, GQ1b is restricted to the sensory regions. When GQ1b stain was compared with parvalbumin, known as a marker of proprioceptive neuron in dorsal root ganglia, parvalbumin staining was completely negative in the nerve endings of motor regions, whereas a few of them were GQ1b positive. GQ1b stain may reflect a few distribution of group II sensory nerve endings in the polar regions, and anti-GQ1b antibodies may be useful as a sensory nerve marker in muscle spindles. Anti-parvalbumin antibody may be used as a putative proprioceptive (group Ia) nerve marker also in the muscle spindle.
  • Hiroki Bochimoto, Daisuke Koga, Yuko Sakai, Yoshiki Hira, Masahiro Hos ...
    2013 年 74 巻 1 号 p. 41-57
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    Gonadotropin-releasing hormone (GnRH) agonists exert acutely stimulatory action on gonadotropes, but thereafter suppress paradoxically gonadotropin synthesis and release by receptor desensitization. To examine whether GnRH signaling affects the morphological characteristics in membranous organelles related to the synthesis of gonadotropin, we have analyzed the ultrastructural changes in the ER and Golgi apparatus of male rat pituitary gonadotropes during sustained treatment with a GnRH agonist, leuprorelin. In pituitary gonadotropes at 1 day after the onset of treatment, clusters of the tubuloreticular ER appeared, and the globular Golgi apparatus was transiently disassembled into isolated small-sized stacks. However, 1 week after the onset of the treatment, the tubuloreticular ER was seemingly converted to rough ER with regularly stacked sheets and the scattered Golgi stacks converged to form globular structures. In the following chronic phase of the treatment, the ER cisterns remained flattened and the trans-Golgi compartment appeared to be collapsed. Sustained treatment with leuprorelin could also restore the enlarged Golgi apparatus and expand the cisterns of the rough ER; a feature that was seen in hypertrophic gonadotropes of castrated rats. These findings indicated that the ultrastructure of the membranous organelles changed because of the chronic suppressive effects of leuprorelin on gonadotropes both in the physiological and stimulated states. The acute and chronic ultrastructural changes in the ER and Golgi apparatus during sustained leuprorelin treatment also suggests that GnRH signaling cross-talks with the regulation of the morphological characteristics in membranous organelles related to gonadotropin synthesis.
  • Mitsutaka Miura, Yoshihiro Mezaki, Mayako Morii, Taku Hebiguchi, Hiroa ...
    2013 年 74 巻 1 号 p. 59-70
    発行日: 2013年
    公開日: 2015/07/18
    ジャーナル フリー
    The “liver” of puffer fish had both a hepatic portion and a pancreatic portion. The hepatic portion had the parenchyma and the portal area as mammalian livers such as human or mouse or rat. However, the hepatic lobule was not obvious histologically in the puffer liver. In the hepatic parenchyma, both parenchymal cells (hepatocytes) and non-parenchymal cells such as liver sinusoidal endothelial cells and hepatic stellate cells (vitamin A-storing cells, Ito cells) were demonstrated to exist. Cytoplasm of the parenchymal cells was filled with large fat droplets, namely, the liver was in steatosis, but neither hepatic fibrosis nor liver cirrhosis was identified. In the pancreatic portion, pancreatic acinar cells containing
feedback
Top