• 제목/요약/키워드: Generation of Mechanisms

검색결과 597건 처리시간 0.026초

Condurango (Gonolobus condurango) Extract Activates Fas Receptor and Depolarizes Mitochondrial Membrane Potential to Induce ROS-dependent Apoptosis in Cancer Cells in vitro -CE-treatment on HeLa: a ROS-dependent mechanism-

  • Bishayee, Kausik;Mondal, Jesmin;Sikdar, Sourav;Khuda-Bukhsh, Anisur Rahman
    • 대한약침학회지
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    • 제18권3호
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    • pp.32-41
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    • 2015
  • Objectives: Condurango (Gonolobus condurango) extract is used by complementary and alternative medicine (CAM) practitioners as a traditional medicine, including homeopathy, mainly for the treatment of syphilis. Condurango bark extract is also known to reduce tumor volume, but the underlying molecular mechanisms still remain unclear. Methods: Using a cervical cancer cell line (HeLa) as our model, the molecular events behind condurango extract's (CE's) anticancer effect were investigated by using flow cytometry, immunoblotting and reverse transcriptase-polymerase chain reaction (RT-PCR). Other included cell types were prostate cancer cells (PC3), transformed liver cells (WRL-68), and peripheral blood mononuclear cells (PBMCs). Results: Condurango extract (CE) was found to be cytotoxic against target cells, and this was significantly deactivated in the presence of N-acetyl cysteine (NAC), a scavenger of reactive oxygen species (ROS), suggesting that its action could be mediated through ROS generation. CE caused an increase in the HeLa cell population containing deoxyribonucleic acid (DNA) damage at the G zero/Growth 1 (G0/G1) stage. Further, CE increased the tumor necrosis factor alpha ($TNF-{\alpha}$) and the fas receptor (FasR) levels both at the ribonucleic acid (RNA) and the protein levels, indicating that CE might have a cytotoxic mechanism of action. CE also triggered a sharp decrease in the expression of nuclear factor kappa-light-chain-enhancer of activated B cells ($NF-{\kappa}B$) both at the RNA and the protein levels, a possible route to attenuation of B-cell lymphoma 2 (Bcl-2), and caused an opening of the mitochondrial membrane's permeability transition (MPT) pores, thus enhancing caspase activities. Conclusion: Overall, our results suggest possible pathways for CE mediated cytotoxicity in model cancer cells.

N-메칠-4-페닐피리디니움 및 6-히드록시도파민으로 유도된 도파민계 신경세포 사멸 기작의 규명 (Characterization of Dopaminergic Neuronal Cell Death Induced by either N-Methyl-4-Phenylpyridinium of 6-hydroxydopamine)

  • 오영준;최원석
    • 약학회지
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    • 제41권1호
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    • pp.86-93
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    • 1997
  • Even though both N-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP) and 6-hydroxydopamine have been widely used to establish the experimental model for dopaminergic neuronal ce ll death. mechanisms underlying this phenomenon have not been firmly explored. To investigate how these dopaminergic neurotoxins induce neuronal cell death, murine dopaminergic neuronal cell line, MN9D cells were treated with various concentration of either 6-hydroxydopamine or active form of MPTP, N methyl-4-phenylpyridinium (MPP$^+$). Treatment of cells with 5-100 uM 6-hydroxydopamine resulted in apoptotic cell death whereas cell death induced by 5~50 uM MPP$^+$ was not demonstrated typical apoptotic characteristics such as cell shrinkage, apoptotic body and nuclear condensation. Cell death induced by 6-hydroxydopamine was partially blocked in the presence of antioxidants including soluble form of vitamin E or desferrioxamine suggesting that generation of oxidative stress may be associated with 6-hydroxydopamine-induced cell death in MN9D cells. In contrast, MPP$^+$-induced cell death was not blocked by treatment with any of antioxidants tested. As previously demonstrated that MPP$^+$ caused metabolic alterations such as glucose metabolism, removal of glucose from the medium partially inhibited MPP$^+$-induced cell death suggesting excessive cycles of glycolysis may be associated with MPP$^+$-induced cell death. Taken together, these studies demonstrate that two types of dopaminergic neurotoxins recruit distinct neuronal cell death pathways.

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산화물 반도체의 다양한 처리를 통한 박막트랜지스터의 전기적 특성 향상 (A Review : Improvement of Electrical Performance in the Oxide Semiconductor Thin Film Transistor Using Various Treatment)

  • 김태용;장경수;;;이소진;강승민;;이윤정;이준신
    • 한국전기전자재료학회논문지
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    • 제29권1호
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    • pp.1-5
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    • 2016
  • The ultimate aims of display market is transparent or flexible. Researches have been carried out for various applications. It has been possible to reduced the process steps and get good electrical properties for semiconductors with large optical bandgaps. Oxide semiconductors have been established as one of the leading and promising technology for next generation display panels. In this paper, alternative treatment processes have been tried for oxide semiconductors of thin film transistors to increase the electrical properties of the thin film transistors and to investigate the mechanisms. There exist a various oxide semiconductors. Here, we focused on InGaZnO, ZnO and InSnZnO which are commercialized or researched actively.

Whole genome sequence of Staphylococcus aureus strain RMI-014804 isolated from pulmonary patient sputum via next-generation sequencing technology

  • Ayesha, Wisal;Asad Ullah;Waheed Anwar;Carlos M. Morel;Syed Shah Hassan
    • Genomics & Informatics
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    • 제21권3호
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    • pp.34.1-34.10
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    • 2023
  • Nosocomial infections, commonly referred to as healthcare-associated infections, are illnesses that patients get while hospitalized and are typically either not yet manifest or may develop. One of the most prevalent nosocomial diseases in hospitalized patients is pneumonia, among the leading causes of mortality and morbidity. Viral, bacterial, and fungal pathogens cause pneumonia. More severe introductions commonly included Staphylococcus aureus, which is at the top of bacterial infections, per World Health Organization reports. The staphylococci, S. aureus, strain RMI-014804, mesophile, on-sporulating, and non-motile bacterium, was isolated from the sputum of a pulmonary patient in Pakistan. Many characteristics of S. aureus strain RMI-014804 have been revealed in this paper, with complete genome sequence and annotation. Our findings indicate that the genome is a single circular 2.82 Mbp long genome with 1,962 protein-coding genes, 15 rRNA, 49 tRNA, 62 pseudogenes, and a GC content of 28.76%. As a result of this genome sequencing analysis, researchers will fully understand the genetic and molecular basis of the virulence of the S. aureus bacteria, which could help prevent the spread of nosocomial infections like pneumonia. Genome analysis of this strain was necessary to identify the specific genes and molecular mechanisms that contribute to its pathogenicity, antibiotic resistance, and genetic diversity, allowing for a more in-depth investigation of its pathogenesis to develop new treatments and preventive measures against infections caused by this bacterium.

한방 추출물의 역류성 식도염 점막보호 효과에 대한 스크리닝 (Screening for Mucosal Protective Effects of Various Korean Herbal Medicine Extracts in Gastroesophageal Reflux Disease)

  • 정일하;김민주;신미래;노성수
    • 대한본초학회지
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    • 제39권1호
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    • pp.39-47
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    • 2024
  • Objectives : This study evaluates how various traditional Korean herbal medicines assess MUC5AC expression for esophageal mucosal defense and analyzes the associated mechanisms involved in inflammation. Methods : Forty types of traditional Korean herbal medicines were assessed for in vitro antioxidant activities, and the real-time PCR method was employed to analyze MUC5AC expression under pH 4.5 conditions in human esophageal epithelial cells (HET-1A). Eight types of Korean herbal medicines were evaluated for in vitro antioxidant activities, and Reactive oxygen specise (ROS) expression was analyzed under bile salt (480 𝜇M) and pH 5.5 conditions in human esophageal epithelial cells (HET-1A). Simulation experiments involving bile salts and acidity were conducted for one hour to assess the efficacy of four drugs, and the activities of Mitogen-activated Protein Kinase (MEK), Nuclear Factor Kappa B (NF-𝜅B), and Cyclooxygenase-2 (COX-2) were detected through Western blot analysis. Results : Compared to the Normal group, the Control group exhibited higher ROS generation. Such increased ROS levels were significantly reduced by four extracts: Citrus Unshius Pericarpium (CUP), Cnidium officinale Rhizoma (CR), Ginseng Radix (GR), and Linderae Radix (LR). The protein expression of COX-2 decreased with the treatment of LR, CUP, and CR. Particularly, CUP and CR exhibited superior effects compared to other groups in inhibiting the phosphorylation of NF-𝜅B. Conclusion : Based on the results obtained, we have identified drugs that inhibit oxidative stress and inflammation caused by bile acid in esophageal epithelial cells. Our future plans involve comparing and analyzing the efficacy of these herbal medicines through animal experiments.

Hindsiipropane B alleviates HIV-1 Tat-induced inflammatory responses by suppressing HDAC6-NADPH oxidase-ROS axis in astrocytes

  • Jo, Hyundong;Jang, Ha Young;Youn, Gi Soo;Kim, Donggyu;Lee, Chae Yeon;Jang, Jae Hee;Choi, Soo Young;Jun, Jong-Gab;Park, Jinseu
    • BMB Reports
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    • 제51권8호
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    • pp.394-399
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    • 2018
  • Human immunodeficiency virus-1 (HIV-1) transactivator of transcription (Tat) is an important viral factor in neuro-inflammation. Hindsiipropane B, present in Celastrus hindsii, possesses various biological mechanisms including anti-inflammatory activity. In this report, we explored the regulatory activity of hindsiipropane B on HIV-1 Tat-mediated chemokine production and its mode of action in astrocytes. Hindsiipropane B significantly alleviated HIV-1 Tat-mediated production of inflammatory chemokines, CCL2, CXCL8, and CXCL10. Hindsiipropane B inhibited expression of HDAC6, which is important regulator in HIV-1 Tat-mediated chemokine production. Hindsiipropane B diminished HIV-1 Tat-mediated reactive oxygen species (ROS) generation and NADPH oxidase activation/expression. Furthermore, hindsiipropane B inhibited HIV-1 Tat-mediated signaling cascades including MAPK, $NF-{\kappa}B$, and AP-1. These data suggest that hindsiipropane B exerts its inhibitory effects on HIV-1 Tat-mediated chemokine production via down-regulating the HDAC6-NADPH oxidaseMAPK-$NF-{\kappa}B$/AP-1 signaling axis, and could serve as a therapeutic lead compound against HIV-1 Tat-associated neuro-inflammation.

플라즈마 충진 촉매 시스템을 이용한 에틸렌 저감 연구 (Decomposition of Ethylene using a Hybrid Catalyst-packed Bed Plasma Reactor System)

  • 이상백;조진오;장동룡;목영선
    • 한국대기환경학회지
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    • 제30권6호
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    • pp.577-585
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    • 2014
  • A series of experiments using atmospheric-pressure non-thermal plasma coupled with transition metal catalysts were performed to remove ethylene from agricultural storage facilities. The non-thermal plasma was created by dielectric barrier discharge, which was in direct contact with the catalyst pellets. The transition metals such as Ag and $V_2O_5$ were supported on ${\gamma}-Al_2O_3$. The effect of catalyst type, specific input energy (SIE) and oxygen content on the removal of ethylene was examined to understand the behavior of the hybrid plasma-catalytic reactor system. With the other parameters kept constant, the plasma-catalytic activity for the removal of ethylene was in order of $V_2O_5/{\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ from high to low. Interestingly, the rate of plasma-catalytic ozone generation was in order of $V_2O_5/{\gamma}-Al_2O_3$ > ${\gamma}-Al_2O_3$ > $Ag/{\gamma}-Al_2O_3$, implying that the catalyst activation mechanisms by plasma are different for different catalysts. The results obtained by varying the oxygen content indicated that nitrogen-derived reactive species dominated the removal of ethylene under oxygen-lean condition, while ozone and oxygen atoms were mainly involved in the removal under oxygen-rich condition. When the plasma was coupled with $V_2O_5/{\gamma}-Al_2O_3$, nearly complete removal of ethylene was achieved at oxygen contents higher than 5% by volume (inlet ethylene: 250 ppm; gas flow rate: $1.0Lmin^{-1}$; SIE: ${\sim}355JL^{-1}$).

보양환오탕이 영양혈청결핍에 의한 PC12 세포의 고사에 미치는 영향 (Protective Effects of Boyanghwanoh-tang on Serum and Glucose Deprivation-induced Apoptosis of PC12 Cells)

  • 김종길;정승원;임준모;장호현;윤종민;이기상;문병순
    • 대한한의학회지
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    • 제24권2호
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    • pp.179-192
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    • 2003
  • Objectives : Boyanghwanoh-tang (Buyanhaiwu-tang) has been used as a prescription for stroke, senile and vascular dementia, ischemic brain and heart damage in Oriental traditional medicine. However, there is little known about the mechanism by which the water extracts of Boyanghwanoh-tang (Buyanhaiwu-tang) rescue cells fromthese damages, and little is known about the protective mechanisms of Boyanghwanoh-tang (Buyanhaiwu-tang) on oxidative stress in neuronal cells. Therefore, we have investigated the role of Boyanghwanoh-tang (Buyanhaiwu-tang) on serum and glucose deprived apoptosis in PC12 cells. Methods : PC12 Cells have been used extensively as a model for studying the cellular and molecular effects of neuronal cells. The viability of cells was measured by MIT assay. We used DNA fragmentation and caspase 1, 2, 3, 6, 9-likeproteases activation assay. Transcriptional activation of NF-kB was assessed by using electrophoretic mobility shift assay. Results : Boyanghwanoh-tang (Buyanhaiwu-tang) rescued PC12 cells from apoptotic death by serum and glucose deprivation in a dose-dependent manner. The nuclear staining of PC12 cells clearly showed that Boyanghwanoh-tang (Buyanhaiwu-tang) attenuated nuclear condensation and fragmentation, which represent typical neuronal apoptotic characteristics. Boyanghwanoh-tang (Buyanhaiwu-tang) also prevents fragmentation of genomic DNA and activation of caspase 3-like protease in serum and glucose deprived PC12 cells. Furthermore, Boyanghwanoh-tang (Buyanhaiwu-tang) reduced the activation of NF-kB by serum and glucose-deprived apoptosis. Conclusions : These findings suggest that serum and glucose deprivation induces reduced glutathione (GSH) depletion, and consequently, apoptosis through endogenously produced reactive oxygen species in PC12 cells. Also, our data indicated that Boyanghwanoh-tang (Buyanhaiwu-tang) has protective effects against the serum and glucose deprived deaths of PC12 cells, which are mediated by the generation of GSH that, in turn, can reduce oxidative stress caused by reactive oxygen species (ROS) such as hydrogen peroxide.

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Curcumin Inhibits the Activation of Immunoglobulin E-Mediated Mast Cells and Passive Systemic Anaphylaxis in Mice by Reducing Serum Eicosanoid and Histamine Levels

  • Li, Xian;Lu, Yue;Jin, Ye;Son, Jong-Keun;Lee, Seung Ho;Chang, Hyeun Wook
    • Biomolecules & Therapeutics
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    • 제22권1호
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    • pp.27-34
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    • 2014
  • Curcumin is naturally occurring polyphenolic compound found in turmeric and has many pharmacological activities. The present study was undertaken to evaluate anti-allergic inflammatory activity of curcumin, and to investigate its inhibitory mechanisms in immunoglobulin E (IgE)/Ag-induced mouse bone marrow-derived mast cells (BMMCs) and in a mouse model of IgE/Ag-mediated passive systemic anaphylaxis (PSA). Curcumin inhibited cyclooxygenase-2 (COX-2) dependent prostaglandin $D_2$ ($PGD_2$) and 5-lipoxygenase (5-LO) dependent leukotriene $C_4$ ($LTC_4$) generation dose-dependently in BMMCs. To probe the mechanism involved, we assessed the effects of curcumin on the phosphorylation of Syk and its downstream signal molecules. Curcumin inhibited intracellular $Ca^{2+}$ influx via phospholipase $C{\gamma}1$ ($PLC{\gamma}1$) activation and the phosphorylation of mitogen-activated protein kinases (MAPKs) and the nuclear factor-${\kappa}B$ (NF-${\kappa}B$) pathway. Furthermore, the oral administration of curcumin significantly attenuated IgE/Ag-induced PSA, as determined by serum $LTC_4$, $PGD_2$, and histamine levels. Taken together, this study shows that curcumin offers a basis for drug development for the treatment of allergic inflammatory diseases.

Molecular Mechanisms of Generation for Nitric Oxide and Reactive Oxygen Species, and Role of the Radical Burst in Plant Immunity

  • Yoshioka, Hirofumi;Asai, Shuta;Yoshioka, Miki;Kobayashi, Michie
    • Molecules and Cells
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    • 제28권4호
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    • pp.321-329
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    • 2009
  • Rapid production of nitric oxide (NO) and reactive oxygen species (ROS) has been implicated in the regulation of innate immunity in plants. A potato calcium-dependent protein kinase (StCDPK5) activates an NADPH oxidase StRBOHA to D by direct phosphorylation of N-terminal regions, and heterologous expression of StCDPK5 and StRBOHs in Nicotiana benthamiana results in oxidative burst. The transgenic potato plants that carry a constitutively active StCDPK5 driven by a pathogen-inducible promoter of the potato showed high resistance to late blight pathogen Phytophthora infestans accompanied by HR-like cell death and $H_2O_2$ accumulation in the attacked cells. In contrast, these plants showed high susceptibility to early blight necrotrophic pathogen Alternaria solani, suggesting that oxidative burst confers high resistance to biotrophic pathogen, but high susceptibility to necrotrophic pathogen. NO and ROS synergistically function in defense responses. Two MAPK cascades, MEK2-SIPK and cytokinesis-related MEK1-NTF6, are involved in the induction of NbRBOHB gene in N. benthamiana. On the other hand, NO burst is regulated by the MEK2-SIPK cascade. Conditional activation of SIPK in potato plants induces oxidative and NO bursts, and confers resistance to both biotrophic and necrotrophic pathogens, indicating the plants may have obtained during evolution the signaling pathway which regulates both NO and ROS production to adapt to wide-spectrum pathogens.