巻号一覧
26 巻 (2001)
- 6 号 p. 525-
- 5 号 p. 253-
- 4 号 p. 189-
- 3 号 p. 117-
- 2 号 p. 61-
- 1 号 p. 1-
26 巻, 2 号
選択された号の論文の7件中1～7を表示しています
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REGULAR ARTICLES
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Hideyuki Tanaka, Takao Hijikata, Tohru Murakami, Noboru Fujimaki, Haru ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 61-70
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーPlectin is a versatile linker protein which is associated with various types of cytoskeletal components and/or filaments including intermediate filaments. To better understand the functional roles of plectin in smooth muscle cells, we examined the distribution of plectin and other related proteins in rat colon smooth muscles by confocal laser and electron microscopy. The sarcolemma of smooth muscle cells exhibits two ultrastructurally distinct domains, domains associated with dense plaques and caveola-rich domains. Staining with anti-plectin and anti-desmin antibodies showed that plectin was localized along the sarcolemma in an intermittent manner and desmin was distributed in the sarcoplasm and intermittently at the cell periphery where it was codistributed with desmin. Plectin exhibited complementary and non-overlapping distribution to caveolin-1 and dystrophin, components of caveola domains, whereas plectin was codistributed with vinculin, talin and integrin β1, components of dense plaques. Plectin was also codistributed with β2-chain laminin but not with β1-chain laminin. Electron microscopic observations on the sarcolemma revealed close association of intermediate filaments with dense plaques. Correlated confocal and electron microscopy clearly demonstrated that anti-plectin fluorescence corresponded to dense plaques but not to caveola domains in electron microscopic images. These findings indicate that plectin is confined to dense plaques to which desmin intermediate filaments may be anchored in rat colon smooth muscle cells.抄録全体を表示PDF形式でダウンロード (4109K) -
Mitsuru Sato, Mitsutaka Miura, Naosuke Kojima, Nobuyo Higashi, Katsuyu ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 71-77
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーIn normal rat and human, most of the nuclei of hepatic parenchymal cells are centrally located in the cytoplasm. However, it is reported that the nuclei of hepatic parenchymal cells are situated at a deviated position on sinusoidal surfaces under pathological situations such as chronic hepatitis, hepatocellular carcinoma, adenomatous hyperplasia, or regeneration. During a study on the mechanism of extreme vitamin A-accumulation in hepatic stellate cells of arctic animals including polar bears, arctic foxes, bearded seals, and glaucous gulls, we noticed that these arctic animals displayed the nuclear deviation in hepatic parenchymal cells on sinusoidal surfaces. In this study, we assessed the frequency of hepatic parenchymal cells showing the nuclear deviation on the sinusoidal surfaces in arctic animals. A significantly higher frequency of the nuclear deviation in hepatic parenchymal cells was seen in polar bears (89.8±3.4%), arctic foxes (68.6±10.5%), bearded seals (63.6±8.4%), and glaucous gulls (24.2±5.8%), as compared to that of control rat liver (9.8±3.5%). However, no pathological abnormality such as fibrosis or necrosis was observed in hepatic parenchymal and nonparenchymal cells of arctic animals, and there were no differences in the intralobular distribution of parenchymal cells displaying the nuclear deviation in the livers from either arctic animals and control rats. The hepatic sinusoidal littoral cells such as stellate cells or extracellular matrix components in the perisinusoidal spaces may influence the nuclear positioning and hence the polarity and intrinsic physiological function of parenchymal cells.抄録全体を表示PDF形式でダウンロード (3432K) -
Isao Suetake, Liheng Shi, Daisuke Watanabe, Masahiko Nakamura, Shoji T ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 79-86
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーIn cultured cells, the maintenance-type DNA methyltransferase (Dnmt1) is highly expressed during the proliferation stage. In the present study, we detected significant expression of Dnmt1 protein in the nuclear fraction of mouse small intestine. From its mobility in SDS polyacrylamide gel electrophoresis and the specific antibodies against the somatic cell-type Dnmt1, Dnmt1 was determined as a somatic cell type. Immunofluorescence study revealed that the Dnmt1 was highly expressed in the proliferating stem cells in crypts, and was localized in the nuclei. The present results indicate that the expression of Dnmt1 in vivo is also under the control of cell proliferation as in cultured cells.抄録全体を表示PDF形式でダウンロード (432K) -
Amelia Cataldi, Alfredo Grilli, Adriano Antonucci, Domenico Bosco, Cam ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 87-93
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーOxygen supply is essential in the maintenance of the physiological cell metabolism.In fact, both lower and higher O2 concentrations induce modifications of the enzymatic activity of the cell which determine, in turn, morphological changes at nuclear and cytoplasmic level. Among the molecules involved in the maintenance of the cellular homeostasis, the signal transduction pathway PI-3-kinase/AKT-1 should be included. Here we suggest a relationship between the modulation of this pathway and the morphological modifications occurring “in vivo” in myocardial tissue upon hypoxic and hyperoxic stress. In particular, down regulation of this pathway, which when activated is known to deliver an anti-apoptotic signal, is concomitant to the maintenance of the apoptotic events occurring in these cells in response to oxidative stresses.抄録全体を表示PDF形式でダウンロード (363K) -
Asako K. Sato, Nobuaki Yanai, Tadashi Okubo, Kazuhiro J. Mori, Masuo O ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 95-101
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーAfter detachment from the stromal cells, hematopoietic stem cells are thought to differentiate to the cytokine-dependent stages where their growth and differentiation are promoted by these cytokines. To examine the stromal regulation of hematopoietic stem cells, we previously established a primitive hematopoietic stem-like cell line, THS119, whose growth was dependent on the bone marrow stromal cell line, TBR59, and from which IL-3- (THS119/IL-3) or IL-7- (THS119/IL-7) dependent cell lines were then generated. Using these cell lines, we examined the difference in signals mediated by the stromal cells and cytokines. The cytokine-dependent cell lines (THS119/IL-3 and THS119/IL-7) showed induction of STAT5 phosphorylation and target genes for STAT5 such as CIS, pim-1, p21 and bcl-xL upon addition of IL-3 or IL-7. IL-3 or IL-7 also induced STAT5 phosphorylation and STAT5 target genes of the stromal cell-dependent cell line, THS119, in the absence of stromal cells at levels similar to the cytokine-dependent cell lines. However, quite interestingly, TBR59 stromal cells could not induce STAT5 phosphorylation of THS119 cells, although they did induce STAT5 target genes in THS119 cells. In addition, the mRNAs for STAT5 target genes in THS119 cells on the stromal cells seemed to be more stable than those in the cytokine-dependent cell lines. Expression of the antiapoptotic genes bcl-2 and bcl-xL was higher in the stromal cell-dependent cell line than in the cytokine-dependent cell lines. These results suggested that stromal cells and cytokines may provide different signals for growth and differentiation of the hematopoietic cells.抄録全体を表示PDF形式でダウンロード (487K) -
Kenji Sorimachi, Kazumi Akimoto, Yukari Ikehara, Keiichiro Inafuku, Ak ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 103-108
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーWater extracts of the mycelial culture and fruiting bodies of Agaricus blazei Murill were fractionated by ethanol precipitation using various ethanol concentrations. Original water extracts from mycelia (Fraction A-0) and fruiting bodies (Fraction B-0) induced TNF-α secretion by macrophages derived from rat bone marrow. Fractions B-4 and B-5 obtained from ethanol precipitation of fruiting bodies using 44% and 50% ethanol, respectively, and Fraction B-6 obtained from the supernatant at 50% ethanol markedly induced TNF-α secretion. Similar effects were observed in IL-8 secretion by macrophages. Regarding nitric oxide (NO), Fraction B-5 induced a significant increase in NO secretion and Fractions B-4 and B-6 induced slightly NO secretion. Northern blot analysis showed that the increases in cytokine- and NO secretion were due to an increase in cytokine mRNAs or NO synthase mRNA. Therefore, it is concluded that Agaricus blazei Murill components which activate macrophages result in the induction of cytokine- and NO secretion in vitro.抄録全体を表示PDF形式でダウンロード (268K) -
Hiroki Kuwabara, Yasuo Kokai, Takashi Kojima, Reiko Takakuwa, Michio M ...原稿種別: scientific monograph
専門分野: Cell Structure and Function
2001 年 26 巻 2 号 p. 109-116
発行日: 2001年
公開日: 2001/07/23
ジャーナル フリーOccludin is a major membrane component of tight junctions of endothelial cells, though the role of this molecule is not fully understood. RLE cells, derived from rat lung endothelial cells, express a negligible level of occludin with clear expression of E-cadherin and ZO-1 at cell junctions. Introduction of occludin by transfection induced clear junctional expression of occludin with few or no changes of expression of E-cadherin and ZO-1. The paracellular barrier function, as determined by transelectrical resistance and flux of non-ionic small molecules, was not detectably upregulated. When cells expressing occludin were cocultured with RLE cells null for occludin, clear junctional expression of occludin was observed irrespective of the expression of occludin on the apposing cells. Cortical actin was developed at the site of these occludin positive cell junctions. Treatment of cells with an actin depolymerizing agent, mycalolide B, abolished junctional expression of occludin together with E-cadherin and circumferential actin. ZO-1 showed relative resistance to this actin depolymerizing treatment and was maintained at the cell junctions, though fragmentation of immunoreactivity was detectable. Collectively, junctional expression of occludin was not associated with paracellular barrier function in this cell line. There was, however, a close correlation of occludin with the actin cytoskeleton, indicating a role of occludin as an important molecule in the regulation of the actin cytoskeleton in endothelial cells.抄録全体を表示PDF形式でダウンロード (1210K)
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