• Title/Summary/Keyword: Cell formation

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Role of FGF and MEK Signaling in Formation of the Hydrostatic Pressure Receptor Cells during Ascidian Embryogenesis (멍게의 수압수용체세포 형성에서 FGF와 MEK 신호의 역할)

  • Seo, Hyeong-Joo;Kim, Gil-Jung
    • Development and Reproduction
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    • v.13 no.4
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    • pp.291-296
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    • 2009
  • In most larvae of ascidian, two sensory pigment cells, otolith and ocellus, lie in their brain vesicle. They also have a third type of sensory cells: hydrostatic pressure receptor (Hpr) cells. The Hpr cells were presumed to be hydrostatic pressure-detection cells, but their precise functions is still disputed. In this study, we investigated whether an FGF signaling is involved in formation of Hpr cells. When fertilized eggs were injected with Hr-FGF9/16/20 antisense MO, the resulting larvae showed severe abnormalities with no expression of the Hpr cell-specific Hpr-1 antigen. Similar results were obtained using an FGF receptor inhibitor, SU5402, and an MEK inhibitor, U0126. Embryos treated with SU5402 or U0126 during the 32-cell and hatching stages did not express the Hpr-1 antigen. To elucidate the temporal requirement for the FGF signaling in formation of Hpr cells, embryos were treated with SU5402 for 2 h, or U0126 for 20 min during various embryonic stages. Larvae treated with SU5402 from the 16-cell stage to the 64-cell stage did not express the Hpr-1 antigen, whereas those treated at the early gastrula stage expressed the Hpr-1 antigen. When U0126 treatment was carried out at various stages between the 8-cell and late gastrula stages, larvae scarcely formed the Hpr cells. They showed expression of the Hpr-1 antigen when embryos were placed in U0126 just before the neural plate stage. These results suggest that FGF9/16/20 signaling is involved in formation of Hpr cells from the primary neural induction stage to the late gastrula stage.

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Snake Venom-enhanced Cytotoxic Effect of Natural Killer Cells on A549 Human Lung Cancer Cell Growth (사독의 인체 폐암세포(A549)에 대한 Natural Killer 세포 세포독성 촉진 효과)

  • Lee, Ji In;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • v.32 no.1
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    • pp.79-88
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    • 2015
  • Objectives : The purpose of this research was to investigate the cytotoxic effect of Natural Killer(NK)-92 cell and Snake Venom, and to elucidate its mechanism on human lung carcinoma cell A549. Methods : In order to figure out whether Snake Venom enhances the cytotoxic effect of NK-92 cell in A549 cell, Cell Viability Assay was conducted. Also, in order to observe the changes of Caspase-3 and Caspase-8, both of which are proteinases that advance apoptosis, and the changes of TNRF and DR3, which are Death Receptors of the extrinsic pathway of apoptosis, Western Blot Analysis was conducted. By conducting RT-PCR analysis, we have tried to confirm Perforin, Granzyme B, and GADPH, all of which are cytotoxic-related proteins. Lastly, in order to observe the effect of Snake Venom on NO formation within human lung carcinoma cells, NO determination was conducted. Results : 1. After conducting Cell Viability Assay, Snake Venom enhanced the cytotoxic effect of NK-92 cell and inhibited the growth of A549. 2. Western Blot Analysis caused proteinases Caspase-3 and Caspase-8, which advance apoptosis, to increase in the combined treatment group, but not in treatment groups that focused only on either Snake Venom or NK-92 cell in A549 lung carcinoma cells. 3. Western Blot Analysis caused an expression of TNFR2 and DR3, both of which are Death Receptors of the apoptosis extrinsic pathway, in the combined treatment group, but not intreatment groups that focused only on either Snake Venom or NK-92 cell in A549 human lung carcinoma cells. 4. After conducting NO determination, NO formation within A549 cell showed no significant changes in both treatment groups that focused NK-92 cell and combined treatment group. 5. After conducting RT-PCR, the expression of Granzyme B and Perforin, which are cytotoxic-related proteins within A549 human lung carcinoma cells, showed growth in the combined treatment group, but not the treatment group that focused only on NK-92 cell. Conclusion : It has been indicated that, when it comes to the A549 cell, Snake Venom enhances the increase of Death Receptor expression and continuous apoptosis reaction, leading to the enhancement of the cancer cell cytotoxic effect of the NK-92 cell. It is expected that Snake Venom can be used with the NK-92 cell for further lung cancer treatment.

Identification of Phosphatidylcholine-Phospholipase D and Activation Mechanisms in Rabbit Kidney Proximal Tubule Cells

  • Chung, Jin-Ho;Chae, Joo-Byung;Chung, Sung-Hyun
    • BMB Reports
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    • v.29 no.1
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    • pp.11-16
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    • 1996
  • The present study showed that receptor-mediated activation of rabbit kidney proximal tubule cells by angiotensin II, the $Ca^{2+}$ ionophore A23187, or the protein kinase C activator phorbol myristate acetate (PMA) all stimulated phospholipase D (PLD). This was demonstrated by the increased formation of phosphatidic acid, and in the presence of 0.5% ethanol, phosphatidylethanol (PEt) accumulation. Angiotensin II leads to a rapid increase in phosphatidic acid and diacylglycerol, and phosphatidic acid formation preceeded the formation of diacylglycerol. This result suggests that some phosphatidic acid seems to be formed directly from phosphatidylcholine hydrolyzed by Pill. On the other hand, EGTA substantially attenuated angiotensin II and A23187-induced PEt formation, and when the cells were pretreated with verapamil angiotensin II-induced Pill activation was completely abolished. These results provide the evidence that calcium ion influx is essential for the agonist-induced Pill activation. In addition, staurosporine, an inhibitor of protein kinase C, strongly inhibited PMA-induced PEt formation, but was ineffective on angiotensin II-induced PEt accumulation. $GTP{\gamma}S$ also stimulates PEt formation in digitonin-permeabilized cells, but pretreatment of the cells with pertussis toxin failed to suppress angiotensin II-induced PEt formation. From these results, we conclude that in the rabbit kidney proximal tubule cells the mechanisms of angiotensin II- and PMA-induced Pill activation are different from each other and mediated via a pertussis toxin-insensitive trimeric G protein.

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Virulence genes of Streptococcus mutans and dental caries

  • You, Yong-Ouk
    • International Journal of Oral Biology
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    • v.44 no.2
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    • pp.31-36
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    • 2019
  • Streptococcus mutans is one of the important bacteria that forms dental biofilm and cause dental caries. Virulence genes in S. mutans can be classified into the genes involved in bacterial adhesion, extracellular polysaccharide formation, biofilm formation, sugar uptake and metabolism, acid tolerance, and regulation. The genes involved in bacterial adhesion are gbps (gbpA, gbpB, and gbpC) and spaP. The gbp genes encode glucan-binding protein (GBP) A, GBP B, and GBP C. The spaP gene encodes cell surface antigen, SpaP. The genes involved in extracellular polysaccharide formation are gtfs (gtfB, gtfC, and gtfD) and ftf, which encode glycosyltransferase (GTF) B, GTF C, and GTF D and fructosyltransferase, respectively. The genes involved in biofilm formation are smu630, relA, and comDE. The smu630 gene is important for biofilm formation. The relA and comDE genes contribute to quorumsensing and biofilm formation. The genes involved in sugar uptake and metabolism are eno, ldh, and relA. The eno gene encodes bacterial enolase, which catalyzes the formation of phosphoenolpyruvate. The ldh gene encodes lactic acid dehydrogenase. The relA gene contributes to the regulation of the glucose phosphotransferase system. The genes related to acid tolerance are atpD, aguD, brpA, and relA. The atpD gene encodes $F_1F_0$-ATPase, a proton pump that discharges $H^+$ from within the bacterium to the outside. The aguD gene encodes agmatine deiminase system and produces alkali to overcome acid stress. The genes involved in regulation are vicR, brpA, and relA.

Hypoxia-dependent mitochondrial fission regulates endothelial progenitor cell migration, invasion, and tube formation

  • Kim, Da Yeon;Jung, Seok Yun;Kim, Yeon Ju;Kang, Songhwa;Park, Ji Hye;Ji, Seung Taek;Jang, Woong Bi;Lamichane, Shreekrishna;Lamichane, Babita Dahal;Chae, Young Chan;Lee, Dongjun;Chung, Joo Seop;Kwon, Sang-Mo
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.2
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    • pp.203-213
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    • 2018
  • Tumor undergo uncontrolled, excessive proliferation leads to hypoxic microenvironment. To fulfill their demand for nutrient, and oxygen, tumor angiogenesis is required. Endothelial progenitor cells (EPCs) have been known to the main source of angiogenesis because of their potential to differentiation into endothelial cells. Therefore, understanding the mechanism of EPC-mediated angiogenesis in hypoxia is critical for development of cancer therapy. Recently, mitochondrial dynamics has emerged as a critical mechanism for cellular function and differentiation under hypoxic conditions. However, the role of mitochondrial dynamics in hypoxia-induced angiogenesis remains to be elucidated. In this study, we demonstrated that hypoxia-induced mitochondrial fission accelerates EPCs bioactivities. We first investigated the effect of hypoxia on EPC-mediated angiogenesis. Cell migration, invasion, and tube formation was significantly increased under hypoxic conditions; expression of EPC surface markers was unchanged. And mitochondrial fission was induced by hypoxia time-dependent manner. We found that hypoxia-induced mitochondrial fission was triggered by dynamin-related protein Drp1, specifically, phosphorylated DRP1 at Ser637, a suppression marker for mitochondrial fission, was impaired in hypoxia time-dependent manner. To confirm the role of DRP1 in EPC-mediated angiogenesis, we analyzed cell bioactivities using Mdivi-1, a selective DRP1 inhibitor, and DRP1 siRNA. DRP1 silencing or Mdivi-1 treatment dramatically reduced cell migration, invasion, and tube formation in EPCs, but the expression of EPC surface markers was unchanged. In conclusion, we uncovered a novel role of mitochondrial fission in hypoxia-induced angiogenesis. Therefore, we suggest that specific modulation of DRP1-mediated mitochondrial dynamics may be a potential therapeutic strategy in EPC-mediated tumor angiogenesis.

A Study on the Characteristic of High Tc Oxide Superconductor, Bi-Pb-Sr-Ca-Cu-O System (Bi-Pb-Sr-Ca-Cu-O계 산화물 고온초전도체의 특성에 관한 연구)

  • Kim, Y.S.;Lee, M.S.;Lee, M.S.;Jin, Y.C.
    • Journal of the Korean Society for Heat Treatment
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    • v.4 no.1
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    • pp.13-18
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    • 1991
  • The formation of high $T_c$ phase is very sluggish and c parameter of unit cell of high $T_c$ phase is about $37{\AA}$. High $T_c$ oxide superconductor with a $T_c$ above 100 K has been successfully prepared by solid state reaction method in BiSrCaCuO system by Pb adding. The microstructure related to the formation of the high $T_c$ phase has been investigated. As compared with YBCO compound, the formation reaction of the high $T_c$ requires long time heat treatment. It is due to the transformation from the low $T_c$ phase to high $T_c$ phase. The sintering just below the melting point of the calcined powder mixture is effective on the formation of the high $T_c$ phase in Pb-added BiSrCaCuO system. The growth of the high $T_c$ superconducting phase has a thin plate shape, which is characterized by the c parameter of $37{\AA}$. The formation of the high $T_c$ phases is delayed by the excessive addition of Pb. The lattice parameter(c) of the unit cell (both the low and high $T_c$ phases) is increased with increase of Pb.

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Study on In Vitro Development of Mouse Embryos (생쥐 수정란의 핵이식후 체외발달에 관한 연구)

  • 박희성;이효종;최상용;박충생
    • Korean Journal of Animal Reproduction
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    • v.14 no.3
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    • pp.205-211
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    • 1990
  • Single nuclei from two-, four- and eight-cell mouse embryos were transplanted into enucleated two-cell mouse embryos by micromanipulation and sendai virum mediated fusion. no significant difference in successful injectin rate and fusion rate was found between the cell stages of nuclear donor embryos. There nuclear transplant embryos receiving different cell stage nuclei were cultured in vitro for 96 hours. 75.3% of 255 embryos receiving 2-cell nuclei, 68.2% of 236 embryos reciving 4-cell nuceli and 46.9% of 228 embryos receiving 8-cell nuclei were developed to blastocyst, respectively. The number of blastomeres was significantly(P<0.05) reduced in the embryos receiving 8-cell nuclei, compared with the embryos receiving 2-cell, 4-cell nuclei or the intact embryos. Also the size of blastocysts was significantly(P<0.05) smaller in the embryos receiving 8-cell nuclei, compared with the intact or other nuclear transplant embryos. These results suggest that single nuclei introduced into the enucleated two-cell embryos are able to support the in vitro development of the reconstituted embryos to blastocysts. The prominant retardation of blastocoele formation and cell division was shown in nuclear transplant embryos receiving eight-cell nuclei when they were cultured in vitro.

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Study on the Effect of Yipahnsan(立安散) on Angiogenic Inhibition Mechanism (입안산(立安散)이 Angiogenesis 억제기전(抑制棋戰)에 미치는 영향(影響))

  • Lee, Gi-Ryong;Choi, Seung-Hoon;Ahn, Kyoo-Seok
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.4 no.1
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    • pp.177-197
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    • 1998
  • This experimental study was carried out to evaluate the effect of Yipahnsan on angiogenic inhibition mechanism. This study investigates the effects of Yipahnsan on angiogenic inhibition mechanism evaluate cell adhesive inhibition effect, DNA fragmantaion analysis, nuclear condensation assay, FACScan analysis, angiogenic lumen formation assay, immunocytochemistry analysis, RT-PCR for mRNA expression, western blot analysis, confocal analysis for $Ca^{2+}influx$. The results were summarized as follows : 1. The cell adhesive inhibition ability was strongly increased from $5{\mu}g/ml$ on ECV304 cell line and ECVPAR cell line. 2. YY water extract caused $G_0/G_1$ arrest peak to existed on the ECV304 cell line. 3. YY water extract caused inhibition of proliferation and inducement of apoptosis on the collagen coated plate in ECV304 cell line. 4. YY water extract inhibited the lumen formation on the matrigel coated plate in ECV304 cell line. 5. YY water extract inhibited the expressions of LFA-1 and ELAM-1 on ECV304 cell line and ECVPAR cell line. 6. YY water extract inhibited the expressions of MMP-9 and uPA on ECV304 cell line and ECVPAR cell line. 7. YY water extract inhibited the expression of integrin ${\alpha}_v{\beta}_3$ on ECV304 cell line and ECVPAR cell line. 8. YY water extract decreased the change of $Ca^{2+}$ in intracellular on ECV304 cell line and ECVPAR cell line. According to the results, Yipahnsan showed to be a key antagonist of integrin ${\alpha}_v{\beta}_3$, and to be induction of apoptosis by p53 through flow cytometry. This report also demonstrated that expressions of MMP-9 and uPA were blocked under the angiogenesis model. Thus, we suggested that Yipahnsan blocks angiogenesis by inducing apoptosis in ECV304 and ECVPAR cell lines, and another oriental herbal medicine that treats qi-stagnation and blood-stasis type also has angiogenic inhibition effects.

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An Experimental study on the effects of Hyperbaric oxygen therapy on the healing process of mandibular fracture of normal rats and streptozotocin-prduced diabetic rats (일반백서와 당뇨백서에서의 하악골절 치유시 고압산소요법이 미치는 영향에 관한 실험적 연구)

  • Yoon, Jung-Ho
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.12 no.3
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    • pp.93-102
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    • 1990
  • The main objectives of this study was to observe the effects of Hyperbaric oxygen therapy on the healing processes of mandibuar fracture of normal rats & streptozotocin - induced diabetic rats. Author used 120 rats (Sprague - Dawley Strain) dividing into controf (60) & experimental group (60) of normal & diabetic rats. Complete fracture was produced on the left mandibular body of 120 rats, rendered hyperbaric oxygen therapy (2 hrs, daily at 2.5 atm) on experimental group and observed effects of hyperbaric oxygen therapy microscopically. The obtained results were as follows : 1. The experimental group of HBO in normal rats had the good effect until 6th week, especially the better effect at 3rd week, because of decrease of inflammatory cell infiltration, heavy proliferation of fibroblast & capillary and active callus formation. 2. The hyperbaric oxygen therapy in mandibular fracture of diabetic rats influenced especially on the healing process at 5th week, because there were much decrease of inflammatory cell infiltrations, heavy proliferation of fibroblast, capillary, osteoblasts, moderate fibrous callus formation, osteocastic activity and mild bony callus formation.

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A Study on Callus Formation and Differentiation in Korean Local Varieties of Adzuki Bean(Phaseolus angularis) (Adzuki Bean(팥)의 Callus형성과 분화에 관한 연구)

  • Choi, Kwan Sam;Kim, Dong Myong;Chung, Won Ill
    • Korean Journal of Agricultural Science
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    • v.15 no.1
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    • pp.69-75
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    • 1988
  • This experiment was carried out for the analysis of the ability of callus formation and differentiation in the eight Korean local varieties of adzuki beans (Phaseolus angularis). KLA 102 has the highest ability on the formation of callus (all tissues have 90 % over). Morphological heterogeneity (color and shape) of callus was well reflected to the cell constitution and cell meristematic activities. Meristemoid tissues and rooting were derived from only creamish-white color and soft region of callus.

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