• 제목/요약/키워드: membrane degradation

검색결과 393건 처리시간 0.024초

Gintonin stimulates autophagic flux in primary cortical astrocytes

  • Rahman, Md. Ataur;Hwang, Hongik;Nah, Seung-Yeol;Rhim, Hyewhon
    • Journal of Ginseng Research
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    • 제44권1호
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    • pp.67-78
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    • 2020
  • Background: Gintonin (GT), a novel ginseng-derived exogenous ligand of lysophosphatidic acid (LPA) receptors, has been shown to induce cell proliferation and migration in the hippocampus, regulate calcium-dependent ion channels in the astrocytes, and reduce β-amyloid plaque in the brain. However, whether GT influences autophagy in cortical astrocytes is not yet investigated. Methods: We examined the effect of GT on autophagy in primary cortical astrocytes using immunoblot and immunocytochemistry assays. Suppression of specific proteins was performed via siRNA. LC3 puncta was determined using confocal microscopy. Results: GT strongly upregulated autophagy marker LC3 by a concentration- as well as time-dependent manner via G protein-coupled LPA receptors. GT-induced autophagy was further confirmed by the formation of LC3 puncta. Interestingly, on pretreatment with an mammalian target of rapamycin (mTOR) inhibitor, rapamycin, GT further enhanced LC3-II and LC3 puncta expression. However, GT-induced autophagy was significantly attenuated by inhibition of autophagy by 3-methyladenine and knockdown Beclin-1, Atg5, and Atg7 gene expression. Importantly, when pretreated with a lysosomotropic agent, E-64d/peps A or bafilomycin A1, GT significantly increased the levels of LC3-II along with the formation of LC3 puncta. In addition, GT treatment enhanced autophagic flux, which led to an increase in lysosome-associated membrane protein 1 and degradation of ubiquitinated p62/SQSTM1. Conclusion: GT induces autophagy via mTOR-mediated pathway and elevates autophagic flux. This study demonstrates that GT can be used as an autophagy-inducing agent in cortical astrocytes.

현호색(玄胡索)이 인체간암세포 증식억제 및 apoptosis 유발에 미치는 영향 (Antiproliferative Effect and Apoptotic Mechanism of Extract of Corydalis Yanhusuo on Human Hepatocarcinoma Cells)

  • 오명택;엄현섭;지규용
    • 동의생리병리학회지
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    • 제21권6호
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    • pp.1437-1449
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    • 2007
  • In this study, the effect of extract of Corydalis yanhusuo (ECT) used in Oriental medicine therapy was investigated on the cell growth and apoptosis of HepG2 human hepatoma cells. It was found that ECT could inhibit the cell growth effectively in a dose-dependent manner, which was associated with morphological change and apoptotic cell death such as formation of apoptotic bodies, DNA fragmentation and increased populations of apoptotic-sub G1 phase. And we observed the effects of ECT on loss of mitochondrial membrane potential (MMP), using the JC-1 probe by DNA flow cytometric analysis. Apoptosis of HepG2 cells by ECT was associated with a down-regulation of anti apoptotic Bcl-2 expression, inhibitor of apoptosis proteins (IAPs) expression and proteolytic activation of caspase-3 and caspase-9. However, ECT did not affect the pro-apoptotic Bax expression and activity of caspase-8. ECT treatment also concomitant degradation and /or inhibition of poly (ADP-ribose) polymerase (PARP), phospholipase C-1 ($PLC{\gamma}1$). Furthermore, ECT treatment caused a dose-dependent inhibition of iNOS and cyclooxygenase-2 (Cox-2). Additionally ECT have been implicated in the regulation of telomerase expression. ECT treatment induced the down-regulation of telomerase reverse transcriptase mRNA (hTERT) expression of HepG2 cells. Taken together, these findings suggest that ECT may be a potential chemotherapeutic agent for the control of HepG2 human hepatoma cells.

탈색된 머리카락의 미세구조적 변화 (Ultrastructural Changes of Hair Treated with Bleaching Agent)

  • 장병수;이귀영
    • Applied Microscopy
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    • 제36권1호
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    • pp.25-33
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    • 2006
  • 정상성인 여성의 머리카락에 미용실에서 일반적으로 시술하는 탈색제를 사용한 다음 탈색직후, 탈색 후 10일, 20일이 경과한 머리카락을 채취하여 머리카락의 손상정도를 고배율의 투과 및 주사전자현미경으로 관찰하였다. 탈색직후 머리카락의 표면은 정상 머리카락과 비슷한 상태로 관찰되었으며 비늘이 분리되거나 손상됨 없이 나타났다. 탈색 후 10일 경과된 머리카락은 비늘이 분리되어 있고 일부 큐티클세포의 세포질은 조각이 나 있거나 떨어져 나갔다. 이 시기에 머리카락은 비늘이 떨어져 나가면서 표면에 세포부스러기들이 그대로 부착되어 있고, 비늘의 모양은 끝 쪽이 날카로운 모양을 하고 있었다. 탈색 후 20일이 경과된 머리카락은 표면 전체가 비늘의 분리에 의해서 거칠게 나타났다.

버섯류의 원형질체 나출을 위한 고효율 효소 선발 (Selection of High Efficient Enzyme for Protoplasts Isolation from Mushrooms)

  • 김종군;김진희;공원식;강희완
    • 한국균학회지
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    • 제38권1호
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    • pp.21-24
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    • 2010
  • 현재 시판되고 있는 세포벽 분해 효소 중 cellulase onozuka R-10(Yakult Honsha, Japan), yatalase(Takara), $Glucanex^R$ 200G(Novo Industry, Denmark)를 조합하여 Flammulina velutipes를 대상으로 가장 효율적인 방법을 선발하고, 선발된 방법을 Pleurotus ostreatus, P. eryngii, Hypsizygus marmoreus에 적용하였다. F. velutipes의 포자, 셀로판지에 배양한 균사, homogenizer로 마쇄한 균사체를 대상으로 공시한 세포벽 분해효소를 단독 혹은 조합하여 처리하였다. 그 결과, 포자현탁액이나 셀로판지에 배양한 균사를 사용하는 것에 비해 homogenizer로 마쇄한 균사체를 사용하는 것이 높은 수율로 원형질체를 분리할 수 있었다. 또한 시험에 사용한 효소 중선발된 $Glucanex^R$ 200G와 cellulase onozuka R-10 효소의 혼합 처리에서 고효율의 원형질체가 분리되었다. 분리된 원형질체를 대상으로 재생률을 조사한 결과, 0.39~0.51% 범위의 재생률을 나타내었다

Development of the Pilot System for Radioactive Laundry Waste Treatment Using UV Photo-Oxidation Process and Reverse Osmosis Membrane

  • Park, Se-Moon;Park, Jong-Kil;Kim, Jong-Bin;Shin, Sang-Woon;Lee, Myung-Chan
    • Nuclear Engineering and Technology
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    • 제31권5호
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    • pp.506-511
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    • 1999
  • The pilot system for radioactive liquid laundry waste was developed with treatment capacity, 1ton/hr and set up in the Yong Kwang unit #4. The system is composed of tank module, RO systems and a UV/$H_2O$$_2$photo-oxidation unit. The RO system consists of the BW unit (low-pressure RO for brackish water desalination) and the SW unit (high-pressure RO for seawater desalination). The BW unit possesses 4 RO membranes and it can reduce the feed water volume down to 1/10. This concentrated feed water can be reduced again up to 1/10 in its volume in the SW unit composed of 4 RO membranes. The UV/$H_2O$$_2$ photo-oxidation process unit was used for the detergent degradation. The operation of the pilot system was carried out and verified in its capability through the continuous operation and concentration operation using the actual liquid waste from the power plant. The design criteria and data for industrialization were yielded. The efficiency of the UV/$H_2O$$_2$ photo-oxidation process and the optimum operational procedure were evaluated. The decontamination factors for radioactive cobalt and cesium were measured. This on-site test showed the experimental result in the DF$\geq$300 and volume reduction factor$\geq$100.

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영양혈청 결핍성 PC12 세포고사에서 HO-1의 발현 증가를 통한 환소단의 보호 효과 (Protective Effect of Hwansodan in Serum and Glucose Deprivation Induced-apoptotic Death of PC12 Cells Via Ho-1 Expression)

  • 정재은;김진경;강백규;박찬희;박래길;문병순
    • 동의생리병리학회지
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    • 제20권6호
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    • pp.1459-1466
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    • 2006
  • The water extract of Hwansodan has been traditionally used for treatment of ischemic brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of Hwansodan rescues cells from neurodegenerative disease. PC12 pheochromocytoma cells have been used extensively as a model for studying the cellular and molecular mechanisms of neuronal cell damages. Under deprivation of growth factor and ischemic injury, PC12 cells spontaneously undergoes apoptotic cell death. Serum and glucose deprivation markedly decreased the viability of PC12 cells, which was characterized with apparent apoptotic features such as membrane blebbing as well as fragmentation of genomic DNA and nuclei. However, the aqueous extract of Hwansodan significantly reduced serum and glucose deprivation-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Pretreatment of Hwansodan also ingibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 was completely abolished in serum and glucose deprivated cells. Furthermore, pretreatment of Hwansodan obviously increased heme oxygenase 1 (HO-1) expression in PC12 cells. Taken together, the data suggest that the protective effects of Hwansodan against serum and glucose deprivation induced oxidative injuries may be achieved through the scavenging of reactive oxygene species accompanying with HO-1 induction.

Expressed Sequence Tag Analysis of the Erythrocytic Stage of Plasmodium berghei

  • Seok, Ji-Woong;Lee, Yong-Seok;Moon, Eun-Kyung;Lee, Jung-Yub;Jha, Bijay Kumar;Kong, Hyun-Hee;Chung, Dong-Il;Hong, Yeon-Chul
    • Parasites, Hosts and Diseases
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    • 제49권3호
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    • pp.221-228
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    • 2011
  • Rodent malaria parasites, such as Plasmodium berghei, are practical and useful model organisms for human malaria research because of their analogies to the human malaria in terms of structure, physiology, and life cycle. Exploiting the available genetic sequence information, we constructed a cDNA library from the erythrocytic stages of P. berghei and analyzed the expressed sequence tag (EST). A total of 10,040 ESTs were generated and assembled into 2,462 clusters. These EST clusters were compared against public protein databases and 48 putative new transcripts, most of which were hypothetical proteins with unknown function, were identified. Genes encoding ribosomal or membrane proteins and purine nucleotide phosphorylases were highly abundant clusters in P. berghei. Protein domain analyses and the Gene Ontology functional categorization revealed translation/protein folding, metabolism, protein degradation, and multiple family of variant antigens to be mainly prevalent. The presently-collected ESTs and its bioinformatic analysis will be useful resources to identify for drug target and vaccine candidates and validate gene predictions of P. berghei.

Facilitation of SUMO (Small Ubiquitin-like Modifier) Modification at Tau 340-Lys Residue (a Microtubule-associated Protein) through Phosphorylation at 214-Ser Residue

  • Lee, Eun-Jeoung;Hyun, Sung-Hee;Chun, Jae-Sun;Ahn, Hye-Rim;Kang, Sang-Sun
    • Animal cells and systems
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    • 제11권1호
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    • pp.39-50
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    • 2007
  • Tau plays a role in numerous neuronal processes, such as vesicle transport, microtubule-plasma membrane interaction and intracellular localization of proteins. SUMO (Small Ubiquitin-like Modifier) modification (SUMOylation) appears to regulate diverse cellular processes including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin-dependent degradation, as well as gene transcription. We noticed that putative SUMOylation site is localized at $^{340}K$ of $Tau(^{339}VKSE^{342})$ with the consensus sequence information (${\Phi}KxE$ ; where ${\Phi}$ represents L, I, V or F and x is any amino acid). In this report, we demonstrated that $^{340}K$ of Tau is the SUMOylation site and that a point mutant of Tau S214E (an analog of the phospho $^{214}S$ Tau) promotes its SUMOylation at $^{340}K$ and its nuclear or nuclear vicinity localization, by co-immunoprecipitation and confocal microscopy analysis. Further, we demonstrate that the Tau S214E (neither Tau S214A nor Tau K340R) mutant increases its protein stability. However, the SUMOylation at $^{340}K$ of Tau did not influence cell survival, as determined by FACS analysis. Therefore, our results suggested that the phosphorylation of Tau on $^{214}S$ residue promotes its SUMOylation on $^{340}K$ residue and nuclear vicinity localization, and increases its stability, without influencing cell survival.

An Essential Role of the N-Terminal Region of ACSL1 in Linking Free Fatty Acids to Mitochondrial β-Oxidation in C2C12 Myotubes

  • Nan, Jinyan;Lee, Ji Seon;Lee, Seung-Ah;Lee, Dong-Sup;Park, Kyong Soo;Chung, Sung Soo
    • Molecules and Cells
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    • 제44권9호
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    • pp.637-646
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    • 2021
  • Free fatty acids are converted to acyl-CoA by long-chain acyl-CoA synthetases (ACSLs) before entering into metabolic pathways for lipid biosynthesis or degradation. ACSL family members have highly conserved amino acid sequences except for their N-terminal regions. Several reports have shown that ACSL1, among the ACSLs, is located in mitochondria and mainly leads fatty acids to the β-oxidation pathway in various cell types. In this study, we investigated how ACSL1 was localized in mitochondria and whether ACSL1 overexpression affected fatty acid oxidation (FAO) rates in C2C12 myotubes. We generated an ACSL1 mutant in which the N-terminal 100 amino acids were deleted and compared its localization and function with those of the ACSL1 wild type. We found that ACSL1 adjoined the outer membrane of mitochondria through interaction of its N-terminal region with carnitine palmitoyltransferase-1b (CPT1b) in C2C12 myotubes. In addition, overexpressed ACSL1, but not the ACSL1 mutant, increased FAO, and ameliorated palmitate-induced insulin resistance in C2C12 myotubes. These results suggested that targeting of ACSL1 to mitochondria is essential in increasing FAO in myotubes, which can reduce insulin resistance in obesity and related metabolic disorders.

Nrf2 활성화를 통한 익위승양탕(益胃升陽湯)의 간세포 보호 효과 (Hepatoprotective effect of Ikwiseungyang-tang via Nrf2 activation)

  • 진효정;박상미;김은옥;김상찬
    • 대한한의학방제학회지
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    • 제29권4호
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    • pp.167-179
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    • 2021
  • Objectives : Oxidative stress is a important cause of liver disease, and regulation of oxidative stress is essential to maintain the normal metabolic function of the liver. Until a recent date, there has been no studies on the hepatoprotective effect of Ikwiseungyang-tang (IWSYT). Therefore, this study aims to demonstrate the hepatoprotective effect of IWSYT and its related molecular mechanisms on arachidonic acid (AA) + iron induced oxidative stress model in HepG2 cells. Methods : To determine the cytoprotective effect of IWSYT against AA + iron-induced oxidative stress, cell viability, apoptosis-related proteins, intracellular reactive oxygen species (ROS), GSH, and mitochondrial membrane potential (MMP) were measured. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation was analyzed by immunoblot analysis. In addition, Nrf2 transcription activation through ARE binding was measured by reporter gene assays, and the expression of the Nrf2 target antioxidant genes were confirmed by immunoblot analysis. Results : IWSYT increased cell viability from cell death induced by AA + Iron, and inhibited apoptosis by regulating apoptosis-related proteins. Furthermore, IWSYT protected cells by inhibiting intracellular ROS production, GSH depletion, and MMP degradation. Nrf2 activation was increased by IWSYT, and Nrf2 target genes were activated by IWSYT too. Conclusions : These results suggest that IWSYT can protect hepatocytes from oxidative stress through Nrf2 activation and can be potentially applied in the prevention and treatment of liver damage.