• Title/Summary/Keyword: Microfilament

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Improved Method of Rapid Freezing and Freeze-Substitution for Tissue Cells (급속동결(急速凍結)과 동결치환(凍結置換)에 의한 조직세포(組織細胞) 관찰법(觀察法))

  • Han, Sung-Sik;Park, Kyu-Tek
    • Applied Microscopy
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    • v.20 no.2
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    • pp.1-11
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    • 1990
  • The ultrastructure of freeze-substituted Malpighian tubule cells of German cockroach after rapid freezing was compared to that fixed with conventional chemical fixation. As results, freeze-substitution proved to be the superior technique revealing much more structural details of the tissue cells. Especially, all kinds of membrane structures including infoldings, microfilament, microtubules and ribosomes were best preserved in this material.

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Blockage of the Immune Complex-triggered Transmembrane Proximity Between Complement Receptor Type 3 and Microfilaments by Staurosporine and Methyl-2,5-dihydroxycinnamate

  • Poo, Ha-Ryoung;Lee, Young-Ik;Todd, Robert F. III;Petty, Howard R.
    • BMB Reports
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    • v.31 no.1
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    • pp.64-69
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    • 1998
  • Recent studies have suggested that integrin (CR3) participates in the signal transduction pathways of certain GPI-anchored phagocytic receptors including $Fc{\gamma}RIIIB$. One consequence of this functional linkage is an inducible association between CR3 and cortical microfilaments that is triggered by $Fc{\gamma}RIIIB$ binding to immobilized immune complexes (IC). That this signaling event requires the co-expression of $Fc{\gamma}RIIIB$ with CR3 was documented by the use of NIH 3T3 transfectants expressing both CR3 and $Fc{\gamma}RIIIB$ (clone 3-23), CR3 alone (clone 3-19), and $Fc{\gamma}RIIIB$ alone (clone 3-15). Pretreatment of 3-23 cells with protein kinase inhibitors such as staurosporine and methyl 2,5-dihydroxycinnamate (MDHC) blocked IC-stimulated CR3 microfilament proximity without affecting the extent to which $Fc{\gamma}RIIIB$ constrains the lateral membrane mobility of a subset of CR3 on the cell surface (as measured in fluorescence recovery after photobleaching experiments). These data support that CR3 and $Fc{\gamma}RIIIB$ molecules are physically and functionally associated and that ligation of FcgRIIIB triggers CR3-dependent signal transduction.

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Fine Structure of Pericanalicular Cytoplasm of Taurocholic Acid-treated Rat Liver as Revealed by Deep Etching with Rapid Freezing (Taurocholic acid 투여 흰쥐 담세관주위세포질의 미세구조에 관한 급속동결 deep etching법에 의한 연구)

  • Shin, Young-Chul
    • Applied Microscopy
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    • v.28 no.1
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    • pp.73-82
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    • 1998
  • To elucidate how microfilaments and vesicles participate in bile formation, the pericanalicular cytoplasms were observed in the liver of rats treated with taurocholic acid by deep etching with rapid freezing, and copmpared them with the findings on convensional thin sections. The microfilaments were identified around the bile canaliculi in the forms of core filaments of microvilli, filaments of pericanalicular web running in parallel to the border of bile canaliculi, and filaments on the junctional complex. In taurocholic acid-treated rats, microfilaments could be visualized around the bile canaliculi and along their borders. The microfilaments appeared to be installed to link to both the canalicular membrane and vesicles. Such specialized microfilaments are considered to participate in the translocation of vesicles in the pericanalicular cytoplasm. From the evidence, it is assumed that the microfilament induces the vesicles to transport and fuse to bile canalicull into which bile acids is secreted by exocytosis.

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Bending behavior of microfilaments in living cell with nonlocal effects

  • Muhammad Safeer;Muhammad Taj;Mohamed A. Khadimallah;Muzamal Hussain;Saima Akram;Faisal Mehmood Butt;Abdelouahed Tounsi
    • Advances in nano research
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    • v.15 no.1
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    • pp.15-23
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    • 2023
  • Dynamics of protein filamentous has been an active area of research since the last few decades as the role of cytoskeletal components, microtubules, intermediate filaments and microfilaments is very important in cell functions. During cell functions, these components undergo the deformations like bending, buckling and vibrations. In the present paper, bending and buckling of microfilaments are studied by using Euler Bernoulli beam theory with nonlocal parametric effects in conjunction. The obtained results show that the nonlocal parametric effects are not ignorable and the applications of nonlocal parameters well agree with the experimental verifications.

Effect of CD14, Toll-like receptors, cytoskeletal inhibitors and $NF-{\kappa}B$ inhibitor on MMP-8 release from human neutrophils induced by E. coli lipopolysaccharides. (E. coli lipopolysaccharides로 유도된 사람 호중구에서 CD14, Toll-like receptors, cytoskeletal inhibitors 그리고 $NF-{\kappa}B$ inhibitor가 MMP-8 분비에 미치는 영향)

  • Yang, Seung-Min;Kim, Tae-Il;Seol, Yang-Jo;Lee, Yong-Moo;Ku, Young;Chung, Chong-Pyoung;Han, Soo-Boo;Rhyu, In-Chul
    • Journal of Periodontal and Implant Science
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    • v.35 no.2
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    • pp.427-436
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    • 2005
  • Objective: MMP-8 is a neutrophil enzyme and its level increases in some inflammatory diseases, including periodontal disease. We knew that the lipopolysaccharide of E.coli(E-LPS) induced MMP-8 release from human neutrophils. E-LPS is known to induce the production and release of inflammatory cytokines through CD14, Toll-like receptor(TLR). In the present study, we investigated whether MMP-8 release by E-LPS is induced via CD14-TLR pathway and the cellular mechanism of MMP-8 release in human neutrophils. Material and methods: Human neutrophils were isolated from the peripheral blood of healthy donors and pre-incubated in medium containing antibodies against CD14, anti-TLR2 and anti-TLR4 or several inhibitors of microtubules and microfilaments and then incubated with E-LPS. The cells were treated TPCK and E-LPS simultaneously. The MMP-8amount in the culture medium was determined using ELISA. Results: E-LPS increased MMP-8release from neutrophils and its induction was inhibited by anti-CD14 and anti-TLR4 but not by anti-TLR2 antibodies. The inhibitors of microtubule and microfilament polymerization significantly decreased E-LPS-induced MMP-8release. TPCK inhibited E-LPS-induced MMP-8 release. Conclusion: These results suggest that MMP-8 release is induced by E-LPS via the CD14-TLR4 signal pathway in human neutrophils and may be depedent on microtubule and microfilament systems and $NF-{\kappa}B$ pathway.

Ultrastructure of Haustorial Cells of Cuscuta australis R. Brown (실새삼(Cuscuta australis R. Brown) 흡기세포(吸器細胞)의 미세구조(微細構造))

  • Lee, Chai-Doo;Lee, Kyu-Bae
    • Applied Microscopy
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    • v.16 no.2
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    • pp.49-60
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    • 1986
  • Ultrastructures of the large and elongated cells (idioblasts) in the haustorium of a parasitic angiosperm, Cuscuta australis R. Brown growing on the host plant, Trifolium repens L. were investigated by the electron microscopy. The idioblasts were characterized by the presence of a large nucleus, small vacuoles, and dense cytoplasm including a number of various cell organelles such as ribosome, rough endoplasmic reticulum(r-ER), mitochondrion, dictyosome, proplastid, multilamellar structure(MLS), microfilament bundle(MFB), and cytosegresome. Therefore, it is suggested that the idioblasts are metabolical1y very active. Particularly, MLS, MFB, and cytosegresome observed in this study did not appear in the haustorial cells of the other parasitic angiosperms. MLS was transformed into vacuole and also incorporated with cell wall. MFB composed of microfilaments, about each 7.5 nm in diameter, was observed in nucleus and also cytoplasm. Some types of MFB were distinguished on the basis of arrangement of microfilaments. A part of cytoplasm sequestered by stacked cisternae of smooth ER(s-ER), cytosegresome, was altered into a vacuole which was formed by digestion of the sequestered cytoplasm and of cisternae of s-ER. Cell organelles such as MLS, MFB, and cytosegresome were discussed in relation to the metabolic control of the idioblasts.

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Cytoskeletal changes during nuclear and cell division in the freshwater alga Zygnema cruciatum (Chlorophyta, Zygnematales)

  • Yoon, Min-Chul;Han, Jong-Won;Hwang, Mi-Sook;Kim, Gwang-Hoon
    • ALGAE
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    • v.25 no.4
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    • pp.197-204
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    • 2010
  • Cytoskeletal changes were observed during cell division of the green alga Zygnema cruciatum using flourescein isothiocynate (FITC)-conjugated phallacidin for F-actin staining and FITC-anti-$\alpha$-tubulin for microtubule staining. Z. cruciatum was uninucleate with two star-shaped chloroplasts. Nuclear division and cell plate formation occurred prior to chloroplast division. Actin filaments appeared on the chromosome and nuclear surface during prophase, and the F-actin ring appeared as the cleavage furrow developed. FITC-phallacidin revealed that actin filaments were attached to the chromosomes during metaphase. The F-actin ring disappeared at late metaphase. At telophase, FITC-phallacidin staining of actin filaments disappeared. FITC-anti-$\alpha$-tubulin staining revealed that microtubules were arranged beneath the protoplasm during interphase and then localized on the nuclear region at prophase, and that the mitotic spindle was formed during metaphase. The microtubules appeared between dividing chloroplasts. The results indicate that a coordination of actin filaments and microtubules might be necessary for nuclear division and chromosome movement in Z. cruciatum.

Annexin I Stimulates Insulin Secretion through Regulation of Cytoskeleton and PKC Activity

  • Kang, Na-Na;Won, Jong-Hak;Park, Young-Min
    • Animal cells and systems
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    • v.13 no.1
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    • pp.17-23
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    • 2009
  • In previous studies, we found that Annexin I (Anx I) was co-secreted with insulin in response to glucose, and that extracellular Anx I stimulated the release of insulin via the Anx I binding site in rat pancreatic islets and the &-cell line. However, the role that Anx I plays in the insulin secretion was not established. Therefore, in this study, we evaluated the insulin secretion pattern in response to Anx I and the involvement of the cytoskeleton or PKC in Anx Istimulated insulin secretion in MIN6N8a cells. The peak time of insulin secretion in response to Anx I treatment corresponded with the second phase insulin secretion by glucose in the perifused pseudoislets. In addition, Anx I-stimulated insulin secretion was not affect by readily releasable pool depletion. Taken together, these findings indicate that Anx I treatment was associated with movement of the reserve pool of insulin. Furthermore, Anx I-stimulated insulin secretion was attenuated by treatment with a microfilament inhibitor, cytochalasin B, as well as by PKC down regulation. These results indicate that Anx I may be a regulator of second phase insulin secretion.

The Comparison of the Spontaneous Zona Pellucida Hardening and PMA-induced Zona Pellucida Hardening during in Vitro Culture of the Mouse Oocytes (생쥐 난자 배양시의 자발적 투명대 경화 현상과 PMA에 의한 투명대 경화 현상 비교)

  • Kang, Hye-Na;Bae, In-Ha;Kim, Hae-Kwon
    • Clinical and Experimental Reproductive Medicine
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    • v.21 no.1
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    • pp.99-110
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    • 1994
  • One consequence of fertilization in mammals is an increased resistance of the zona pellucida (ZP) to proteases and various chemical reagents. This phenomenon has been called 'zona pellucida hardening' (ZPH), and it is generally accepted that it is caused by the secretory products of cortical granules released by the egg at fertilization. ZP of mouse oocytes maturing in vitro in a chemically defined medium becomes progressively more resistant to solubilization by chymotrypsin ("Spontaneous" ZP hardening). In the present study, it was aimed to find the specificity of spontaneous ZPH in relation to its possible relevance to the cortical reaction and the physiological block to polyspermy. When a maturation inhibitors, cAMP analog(dbcAMP) and phosphodiesterase inhibitor (IBMX) was added to culture medium, it prevent spontaneous ZPH of mouse oocyte during in vitro culture. Thus spontaneous ZPH requires GVBD, since it is prevented by those agents, which inhibit GVBD in vitro. However, culture for 3 hours in the presence of PMA(lOng/ml), a protein kinase C activator, resulted in ZPH without GVBD, thus suggesting that ZPH may be regulated independently apart from the event of GVBD. Pretreatment of mouse oocyte with FBS result in partially inhibitory effect on subsequent spontaneous ZPH. Induction of GVBD in vivo had a inhibitory effect on the spontaneous ZPH, but subsequent spontaneous ZPH. Induction of GVBD in vivo had a inhinbitory effect on the spontaneous ZPII, but had no inhibitory effect on PMA-induced ZPH. Treatment with a microfilament 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 PMA-induced ZPH. Thus this suggesting that spontaneuse ZPH had a different mechanism from PMA-induced ZPH.

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Reviews Value-in-Use of Specific Proteins Induced from Biological Resources (생물자원 유래 특이적 단백질의 이용가치에 관한 고찰)

  • Hyun, Dong-Yun;Kim, Ok-Tae;Bang, Kyong-Hwan;Kim, Young-Chang;Kang, Seung-Weon;Cha, Seon-Woo;Kim, Se-Yun
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2010.05a
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    • pp.3-3
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    • 2010
  • 소나무에서 추출해낸 천연유기유황(Natural Sulfur)의 의학적 가치는 1972년 Jacob 박사와 Herschler 박사가 오래곤 과학대학에서 천연식이유황(Natural Sulfur/MSM)을 가지고 표피조직에 미치는 영향을 구명하면서 keratin 단백질에 대한 연구가 활성화 되기 시작하였다. 세포내 골격물질은 크게 형태와 조성에 따라서 actin microfilament, microtubule, 그리고 intermediate filament(IF)로 구분된다. keratin의 특성은 keratin intermediate family중에서 K17 IF가 새로운 기능을 나타내는데 피부세포의 성장에 핵심적인 조절 역할을 한다는 사실이 밝혀 지면서 Dr. Pierre A. Coulombe(The Johns Hopkins University School of Medicine)연구실은 브로컬리와 같은 십자화과 식물 등에 과량 존재하는 항산화 및 항암물질인 sulforaphane이 K17의 발현을 특이적으로 증가시킨다는 것을 알아내어 피부박리와 같은 피부손상을 기능적으로 복구시킬수 있음을 확인하였다. 현재는 수포성 표피박리증 환자군의 많은 부분을 차지하는 K14 돌연변이와 동일한 유전적 변형을 일으킨 생쥐모델을 이용한 약물 효과 검증과 전 임상단계의 인체실험을 함께 진행중에 있다. Mark E. Van Dyke 박사(Wake Forest Institute for Regenerative Medicine Medical Center)는 인간의 머리털에서 유래된 keratin으로 외상에 의한 신경 절단이나 압좌(압박손상)는 현재 다른 부위의 신경을 잘라 이식하거나 절단된 신경 양끝을 인공도관(conduit)으로 연결해 신경재생을 유도하는 미세수술을 시행하게 되는데, 신경재생을 유도하는 도관에 keratin을 주입하면 신경이식과 맞먹는 신경재생 성공률을 기대할 수 있다고 하였다. 앞으로는 동물성 keratin뿐만 아니라 식물성 keratin도 함께 연구할 필요가 있다. 동물성 keratin의 농업적 이용은 가금류 깃털의 keratin을 축출하여 친환경 육묘용 용기를 만드는데 있다. 이 용기는 자연조건에서 생분해될 수 있는 특성을 갖고 있다.

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