• Title/Summary/Keyword: Cell formation

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Static tensional forces increase osteogenic gene expression in three-dimensional periodontal ligament cell culture

  • Ku, Seung-Jun;Chang, Young-Il;Chae, Chang-Hoon;Kim, Seong-Gon;Park, Young-Wook;Jung, Youn-Kwan;Choi, Je-Yong
    • BMB Reports
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    • v.42 no.7
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    • pp.427-432
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    • 2009
  • Orthodontic tooth movement results from the combinational process of both bone resorption and formation in the compressive and tension sides, respectively. However, the genes responsible for new bone formation in tension sides have not been determined. In this study, we used DNA microarray and real-time RT-PCR to identify genes in human periodontal ligament (PDL) cells that undergo significant changes in expression in response to static tensional forces (2 or 12 hours). The genes found were alkaline phospatase (ALP), matrix metalloproteinases (MMPs), vascular endothelial growth factor (VEGF), and several collagen genes. Furthermore, an ELISA evaluating the expression of VEGF, type IV collagen and MMP-2 found levels significantly increased after 24 and 72 hours (P < 0.05). ALP activity was also increased after 24 hours (P < 0.05). Collectively, we found the genes up-regulated in our study by the static tensional force are related to osteogenic processes such as matrix synthesis and angiogenesis.

An Ultrastructural Study of Tentacular Retractor Muscle of Chinese Mystery Snail, Cipangopaludina chinensis malleata Reeve (논우렁이 촉수(觸手) 수축근(收縮筋)의 미세구조(微細構造))

  • Song, Yong-Jik;Kim, Woo-Kap;Kim, Chang-Whan
    • Applied Microscopy
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    • v.17 no.2
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    • pp.31-40
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    • 1987
  • The tentacular retractor muscle has many arrays of muscle fiber bundles under the epithelial layer. Most of muscle fiber bundles are arranged in parallel to the longitudinal axes of muscle fibers and a small number of them perpendiculary to them. These smooth muscle cells are filled with compactly arranged myosins and actins. These microfilaments, when the tentacle is protracted, keep abreast with straight for-ward-lined shapes while these microfilaments, when it is retracted, with curved shapes. The foldings in the sarcolemma of the muscle cell, when the tentacle is retracted, lead to the formation of normal subsurface tubules along with which a few mitochondria are included. It is thought that the formation of the sarcolemmal differentiation like the subsurface tubules has a close relation with the protraction and retraction of the tentacle. Mitochondria are found throughout the muscle cell, and sarcoplasmic reticulum (SR) developed greatly in the exoplasm close to the sarcolemma and associated with the cell membrane. Dense bodies are distributed irregularly and thin filaments are scattered around the thick filament in cross-sections, but the thin filaments may be arranged in complete or partial orbits around thick filaments. Complete orbits are infrequent.

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The Effect of Laser Irridation on the Ultrastructure of Retina (Laser 조사가 망막의 미세구조에 미치는 영향)

  • Kim, Douk Hoon;Mun, Jung Hak
    • Journal of Korean Ophthalmic Optics Society
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    • v.1 no.1
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    • pp.15-22
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    • 1996
  • The fine structure of retinal tissue was studied to investigate on effect of Laser irridation on the ICR mouse with electron microscope. The results obtained were as follows: 1. At the normal groups, the most retinal layers were a complex structure, consisting of several specific cells and nerve fiver. 2. In the increasing time of Laser irridation, each cell layer of retina was not uniform of the structure and band. The visual cells were severely heterochromatin swelling of cytoplasm, irregular shape & heterochromatin of nuclear, and disappear of some cytoplasm. The nucleus and nerve fiber of retinal layer was a very irregular shape, formation of vesicle, not identify of each intercellular boundary. The pigment epithelial cells were not an uniform, a large vesicle formation of cytoplasm, and a condensation & very irregular shape of nucleus.

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Chemical Coupling between Horizontal Cells in the Catfish Retina

  • Lee, Sung-Jong;Jung, Chang-Sub;Bai, Sun-Ho
    • The Korean Journal of Physiology and Pharmacology
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    • v.2 no.1
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    • pp.21-30
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    • 1998
  • The effects of GABA and glutamate on the horizontal cells were explored by an intracellular recording method to discern the mechanisms of receptive field formation by chemical coupling in the catfish outer retina. The results suggest that the horizontal cells of the catfish retina might use GABA as their transmitters and that the GABAergic system contributes to the formation of receptive fields of the horizontal cells. GABAC receptors may be involved in a chemical coupling between horizontal cells and concerned with the depolarizing actions by GABA on horizontal cells in the catfish retina. Since the chloride equilibrium potential is more positive than the dark membrane potential in horizontal cells, GABA released from a horizontal cell may depolarize the neighboring horizontal cells. Thus a chemical coupling between horizontal cells may be formed. $GABA_A$ receptors also may be involved in the negative feedback mechanism between photoreceptor and horizontal cell. And glutamate may be involved in connecting positive and negative feedback systems since it potentiated the GABA's actions. Therefore, it is presumed that large receptive fields in the catfish retina are formed not only by electrical coupling but also by chemical coupling between horizontal cells. And information travels laterally by pathways involving both electrical coupling composed of gap junctions and chemical coupling in the retinal network.

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miR-9 Modulates Osteosarcoma Cell Growth by Targeting the GCIP Tumor Suppressor

  • Zhu, Shao-Wen;Li, Jian-Peng;Ma, Xin-Long;Ma, Jian-Xiong;Yang, Yang;Chen, Yang;Liu, Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.11
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    • pp.4509-4513
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    • 2015
  • Osteosarcoma is the most common primary bone tumor in humans, especially in childhood. However, the genetic etiology for its pathogenesis remains elusive. It is known that microRNAs (miRNAs) are involved in the development of tumor progression. Here we show that microRNA-9 (miR-9) is a potential oncogene upregulated in osteosarcoma cells. Knockdown of miR-9 in osteosarcoma resulted in suppressed colony formation and cell proliferation. Further study identified GCIP, a Grap2 and cyclin D interacting protein, as a direct target of miR-9. In addition, GCIP overexpression activated retinoblastoma 1 (Rb) and suppressed E2F transcriptional target expression in osteosarcoma cells. Moreover, GCIP depletion reversed miR-9 knockdown induced colony formation and cell proliferation suppression. In sum, these results highlight the importance of miR-9 as an oncogene in regulating the proliferation of osteosarcoma by directly targeting GCIP and may provide new insights into the pathogenesis of osteosarcoma.

Knockdown of SMYD3 by RNA interference inhibits cervical carcinoma cell growth and invasion in vitro

  • Wang, Shu-zhen;Luo, Xue-gang;Shen, Jing;Zou, Jia-ning;Lu, Yun-hua;Xi, Tao
    • BMB Reports
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    • v.41 no.4
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    • pp.294-299
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    • 2008
  • Elevated expression of SMYD3 is a frequent genetic abnormality in several malignancies. Few studies knocking down SMYD3 expression in cervical carcinoma cells have been performed to date. In this paper, we established an inducible short hairpin RNA expression system to examine its role in maintaining the malignant phenotype of HeLa cells. After being induced by doxycycline, SMYD3 mRNA and protein expression were both reduced, and significant reductions in cell proliferation, colony formation and migration/invasion activity were observed in the SMYD3-silenced HeLa cells. The percentage of cells in sub-G1 was elevated and DNA ladder formation could be detected, indicating potent induction of apoptosis by SMYD3 knockdown. These findings imply that SMYD3 plays crucial roles in HeLa cell proliferation and migration/invasion, and that it may be a useful therapeutic target in human cervical carcinomas.

Effects of the Developmental Stage of Extract Donor Embryos on the Culture of Marine Medaka Oryzias dancena Embryonic Stem Cell-like Cells (배아추출물 공여 배아의 발생단계가 바다송사리(Oryzias dancena) 배아 줄기세포 유사세포의 배양에 미치는 영향)

  • Ryu, Jun Hyung;Gong, Seung Pyo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.50 no.2
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    • pp.160-168
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    • 2017
  • Optimizing the conditions for stem cell culture is an essential prerequisite for the efficient utilization of stem cells. In the culture of fish embryonic stem cells (ESCs) or ESC-like cells, embryo extracts are important for stable growth, but there is no rule for determining the developmental stage of the embryos used to obtain extracts. Therefore, this study investigated the effects of the developmental stage of extract donor embryos on the culture of Oryzias dancena ESC-like cells. O. dancena ESC-like cells were cultured in different media containing each of four types of embryo extract depending on the developmental stage of the extract donor embryos. Growth, morphology, colony-forming ability, alkaline phosphatase (AP) activity, and embryoid body (EB) formation of the cells were investigated. While the developmental stage of the extract donor embryos did not influence the growth, morphology, AP activity, or EB formation of ESC-like cells, colony-forming ability was affected and the pattern of the effects differed completely between the two ESC-like cells investigated. These results suggest that the developmental stage of extract donor embryos should be selected carefully for the culture of ESC-like cells, according to the research purpose and type of cell line.

Structural Changes and Histochemical Study of Endosperm on Panax ginseng C.A. Meyer during Embryo Development (인삼(Panax ginseng C.A. Meyer) 종자의 배발달에 따른 배유의 구조변화 및 조직화학적 연구)

  • 유성철;김유갑
    • Journal of Ginseng Research
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    • v.16 no.1
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    • pp.37-43
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    • 1992
  • Structural changes of the endosperm of Panax ginseng C.A. Meyer from fertilization to germination were investigated by light microscope. The endosperm of the ginseng seed is cellular type. Since endosperm cells adjacent embryo continuously breakdown and disappear with the elongation of embryo, the real of endosperm is gradually decreased. As the anatropous ovules of immature seed with green seed coat developes more and more, ovary cells adjacent ovary cavity become abundant by the periclinal division, their size is decreased, hypotrophy of cell wall discern, and they are gradually differentiated in seed coat. Though embryo responds strongly to basic dye at the stage of completion of endosperm formation, tissue of endosperm responds to acidic dye positively Cell wall of embryo and endosperm are composed of primary cell wall not lignified. Endosperm cells adjacent embryo begin to breakdown in the endosperm tissue of indehiscent seed before the beginning of the after-ripening. Dehiscent seed of which seed coat is opened through after-ripening represent the form as a seedling in the result of embryo developments with the formation of organs; radicle, cotyledon, plumule. Umbilifom layer represents strong positive response to the toluidine blue and the basic function. Umbiliform layer that endosperm cells breakdown and disappear is observed clearly at the periphery of the embryo cotylemon, while slightly at the periphery of the radicle.

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Gene Expression in Transformed Higher Plants II. Effect $Ca^{2+}$ on $\beta-Glucan$ Synthetase II Activity and Changes of Peroxidase Pattern in Transformed Potato Tuber (고등 식물의 형질전환에 따른 유전자 발현 II. 형질전환된 감자 괴경의 $\beta-Glucan$ Synthetase II의 활성에 미치는 Ca2+의 효과 및 Peroxidase의 변화 양상)

  • 정현숙
    • Journal of Plant Biology
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    • v.34 no.4
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    • pp.261-266
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    • 1991
  • The hairy root was induced form potato tuber disc by infection of a. rhizogenes. The detection of the agropine and mannopine by paper electrophoresis confirmed that induced hairy root was transformed by A. rhizogenes. The activity of peroxidase was the highest at 5 weeks and isozyme pattern of peroxidase revealed 3 cathodic bands and 2 anodic bands and new C4 band(pI 4.6) was observed at 7 weeks after cultivation in hairy root was isoelectric focusing. To study the effect of Ca2+ on cell wall formation in hairy root, channel blocker of Ca2+ was treated. The activity of $\beta$-glucan synthetase II(GS II) related to cell wall synthesis was inhibited by about 50% in diltiazem and flunarizine treatment than that of control, but stimulated in CaCl2 treatment. Therefore these results showed that Ca2+ might be an effective factor in the cell wall formation. The activity of GS II by NaF treatment was increased by about 30%. This result suggested that the activity GS II is changed through phosphorylation process.

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