• 제목/요약/키워드: exocytosis

검색결과 82건 처리시간 0.032초

Identification of Functionally Different Rat IgE in RBL-2H3 Exocytosis

  • Kim, Jin-Sub;Cho, Sungae;Joo, Kyoung-Hwan;Lee, Joon-Sang;Conrad, Daniel H.;Cho, Sung-Weon
    • IMMUNE NETWORK
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    • 제2권4호
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    • pp.195-201
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    • 2002
  • Background: IgE is closely related to the development of allergies. However, the poor relationship between the specific IgE level and the severity of allergic diseases suggests the possibility of functionally different IgE isoforms. With this in mind, rat basophilic leukemia (RBL)-2H3 activation was analyzed with each type of rat IgE for two parameters, exocytosis and IL-4 mRNA production. RBL-2H3 has been well documented in the rat mucosal mast cell line. Methods: RBL-2H3 cells sensitized with each kind of rat IgE was activated by cross-linking FcRI with B5 (monoclonal anti-rat IgE mouse IgG antibodies). The RBL-2H3 exocytosis was measured by analyzing the ${\beta}$-hexosaminidase level, and the level of IL-4 mRNA synthesis was analyzed using semiquantitative RT-PCR. Rat IgE, which was produced by a parasite infection (REP), was prepared using either Paragonimus westermani metacercariae (REP-PW) or Anisakis simplex third stage larvae (REP-AS). A rat IgE prototype of IR162 was prepared by a peritoneal injection of immunocytoma. Results: The level of exocytosis showed a linear relationship with the rat IgE concentration when REP-PW or REP-AS was applied. However, it exhibited a biphasic response with IR162. In addition, the time course of heating at $56^{\circ}C$ illustrated the similarity between REP-PW and REP-AS, which differed from that of IR162. In contrast, the level of IL-4 mRNA synthesis in the RBL-2H3 cells with IR162 was comparable to that of either REP-PW or REP-AS. Conclusion: These results suggest that functionally different rat IgE isoforms exists in RBL-2H3 exocytosis.

In Vitro Cellular Uptake and Cytotoxicity of Paclitaxel-Loaded Glycol Chitosan Self-Assembled Nanoparticles

  • Park, Ji-Sun;Cho, Yong-Woo
    • Macromolecular Research
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    • 제15권6호
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    • pp.513-519
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    • 2007
  • Self-assembled nanoparticles have great potential to act as vehicles for hydrophobic drug delivery. Understanding nanoparticle cellular internalization is essential for designing drugs intended for intracellular delivery. Here, the endocytosis and exocytosis of fluorescein isothiocyanate (FITC)-conjugated glycol chitosan (FGC) self-assembled nanoparticles were investigated by flow cytometry and confocal microscopy. The cellular internalization of FGC nanoparticles was initiated by nonspecific interactions between nanoparticles and cell membranes. Although adsorptive endocytosis of the nanoparticles occurred quickly, significant amounts of FGC nanoparticles were exocytosed, particularly in the early stage of endocytosis. The amount of exocytosed nanoparticles was dependent on the pre-incubation time with nanoparticles, suggesting that exocytosis is dependent on the progress of endocytosis. FGC nanoparticles internalized by adsorptive endocytosis were distributed in the cytoplasm, but not in the nucleus. In vitro cell cycle analysis demonstrated that FGC nanoparticles delivered paclitaxel into the cytoplasm and were effective in arresting cancer cell growth.

포유류 수정과정에서 정자 침체기질의 기능 (Role of Acrosomal Matrix in Mammalian Fertilization)

  • 김계성
    • 한국수정란이식학회지
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    • 제16권1호
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    • pp.61-68
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    • 2001
  • Sperm competent for fertilization can become capacitated, bind to the zona pellucida (ZP) of an egg in a specific manner, and complete acrosomal exocytosis. Failure to carry out these functions results in infertility. Although the interactions between the ZP and the plasma mem-brane overlying the sperm acrosome have been considered important for sperm-egg recognition and signalling, recent results have prompted a reassessment of current paradigms concerning these interactions. In this review, we're going to discuss about the roles of the acrosomal matrix, the particulate component of the acrosomal contents, in fertilization. The general hypothesis is that acrosomal exocytosis leads to the exposure of acrosomal matrix proteins that become de-facto extracellular matrix (ECM) on the surface of the sperm head, and that the dynamic interactions of this newly-exposed sperm ECM with the egg ECM (the ZP) govern sperm-egg recognition and sperm penetration of the ZP Informations from these experiments may provide new ways to address the poor ZP binding of sperm from some human infertility patients and may offer new avenues for contraception through the disruption of purposeful sperm-ZP binding.

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Modulation of Exocytosis by Protein Kinases and $Ca^{2+}$ in Epithelial Cells:

  • Koh, Duk-Su;Jung, Seung-Ryoung;Kim, Mean-Hwan;Bertil Hille;Toan Nguyen
    • 한국생물물리학회:학술대회논문집
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    • 한국생물물리학회 2002년도 제9회 학술 발표회 프로그램과 논문초록
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    • pp.22-23
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    • 2002
  • In neurons and some endocrine cells, $Ca^{2+}$ plays a pivotal role as the final signal for rapid stimulus-evoked release of neurotransmitters and hormones. In contrast, intracellular signals other than $Ca^{2+}$, such as protein A and C, were mor emphasized the exocytosis in non-neuronal cells. We questioned if the regulatory mechanisms of exocytosis are fundamentally different between cell types.(omitted)

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Constitutive Exocytosis of Seminal Fluid Proteins in Male Accessory Glands and Ejaculatory Duct of Drosophila melanogaster

  • 조경상;김성윤;임점희;정기화;이청주
    • Animal cells and systems
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    • 제1권3호
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    • pp.515-520
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    • 1997
  • Male accessory glands and ejaculatory duct of Drosophila melanogaster are reproductive organs which synthesize secretory seminal proteins. Several products of these organs involved in egg laying, receptivity, and sperm stability or storage were isolated from their lumens. Despite their secretory process play an important role, exocytosis pathway in these organs is not well known. In the present study, we characterized secretory protein profiles and determined their secretory mechanisms. Eight accessory gland secretory proteins and two ejaculatory duct secretory proteins were detected in their lumens. All these proteins were constitutively synthesized in these organs and secreted to their lumens. Secretion of newly synthesized proteins initiated at about 1 h after synthesis, and reached the peak at 4 h after synthesis. It seems that secretion of the proteins may occur via constitutive exocytosis pathway.

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포유류 수정과정에서 정자 첨체기질의 기능 (Role of Acrosomal Matrix in Mammalin Fertilization)

  • Kim, Kye-Seong;George L. Gerton
    • 한국수정란이식학회:학술대회논문집
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    • 한국수정란이식학회 2001년도 춘계학술세미나 및 워크숍
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    • pp.4-16
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    • 2001
  • Sperm competent for fertilization can become capacitated, bind to the zona pellucida (ZP)of an egg in a specific manner, and complete acrosomal exocytosis. Failure to carry out these functions results in infertility. Although the interactions between the ZP and the plasma membrane overlying the sperm acrosome have been considered important for sperm-egg recognition and signalling recent results have prompted a reassessment of current paradigms concerning these interactions. In this review, we're going to discuss about the roles of the acrosomal matrix, the particulate component of the acrosomal contents, in fertilization. The general hypothesis is that acrosomal exocytosis leads to the exposure of acrosomal matrix proteins that become de facto extracellula matrix(ECM) on the surface of the sperm head, and that the dynamic interactions of this newly-exposed sperm ECM with the egg ECM (the ZP) govern sperm-egg recognition and sperm penetration of the ZP. Informations from these experiments may provide new ways to address the poor ZP binding of sperm from some human infertility patients and may offer new avenues for contraception through the disruption of purposeful sperm-ZP binding.

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생쥐 난자 배양시 외분비 관련 요소들이 자발적 투명대 경화 현상에 미치는 영향 (Effect of Exocytosis Factor on Spontaneous Zona Pellucida Hardening during in Vitro Culture of the Mouse Oocytes)

  • 강혜나;배인하;김해권
    • Clinical and Experimental Reproductive Medicine
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    • 제21권1호
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    • pp.111-119
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    • 1994
  • "Spontaneous" hardening of the zona pellucida of mouse oocytes during in vitro culture is most likely due to cortical granules exocytosis. Thus the purpose of the present study was to determine whether the exocytosis factor is involved in spontaneous zona pellucida hardening during in vitro culture of the mouse. The results obtained form these experiments were summarized as follows; 1. When a protein synthesis inhibitor(100${\mu}g$/ml puromycin) was added to the culture medium, it did not prevent spontaneous ZPH of mouse oocyte during in vitro culture. 2. Calmodulin antagonists (trifluoperazine and chlorpromazine) and calcium channel blocker (verapamil) had no inhibitory effect in spontaneous ZPH. 3. A microtubule assembly inhibitor, colcemid had some inhibitory effect on spontaneous ZPH. 4. Treatment with a microfillament formation blocker(cytochalasin-B) at 1${\mu}g$/ml concentration, resulted in the excellent inhibitory effect on spontaneous ZPH. However cytochalasin-B did not inhibit ethanol-induced ZPH.

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PC12 세포 신경전달물질 방출 저해제 S9940이 신경세포 돌기신장에 미치는 영향 (Effect about Neurite Extension of S9940, and Inhibitor of Exocytosis in PC12 Cells)

  • 이윤식;박기인
    • Toxicological Research
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    • 제14권3호
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    • pp.349-356
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    • 1998
  • We identified S9940, a novel microbial metabolite from Streptomyces spp., to inhibit the release of neurotransmitter from PC12 cells. S9940 is an inhibitor of trifiated norepinephrine ([$^{3}H$]-NE) release in high $K^+$ buffer solution containing ionomycin, indicating that S9940 inhibits neurotransmitter release after the influx of $Ca^{2+}$ ions. We also examined the effect of S9940 on $\beta-glucuronidase$ release from guinea pig neurophils and the effect on the neurite extension of PC12 cells and rat hippocampal neurons. As a result, S9940 inhibited $\beta-glucuronidase$ release: when treated with $5{\mu}g/ml$ of S9940, which prevented [$^{3}H$]-NE release, the inhibition of neurite extension for both PC12 cells and rat hippocampal neurons was observed.

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