• 제목/요약/키워드: autophagy

검색결과 471건 처리시간 0.026초

Blastocladiella emersonii의 단축된 포자형성과정에서 관찰된 핵의 소멸 (Nucelear Degeneration During Reduced Sporogenesis in Blastocladiella emersonii)

  • 윤현주;조정원
    • 미생물학회지
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    • 제40권4호
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    • pp.282-285
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    • 2004
  • Zoosporic fungi의 일종인 Blastocladiella emersonii에서는, 적은 수의 핵을 포함하는 작은 크기의 sporangium의 형성을 유도할 수 있다. 이들의 단축된 포자형성과정에서, sporangium내에 존재하던 일부 핵들의 소멸이 관찰되었다. 이 결과는 핵의 소멸이 포자형성과정의 필수적인 부분과정이라는 가설을 뒷받침해준다. 핵의 소멸과정은 형태적으로 세포질의 autophagy와 유사하였으며, autophagy의 형태적인 발달과정을 연구하기 위한 좋은 모델 시스템이 될 것으로 생각한다.

에탄올에 의해 추출한 황금이 구강암 세포에서 나타나는 자가포식작용 (Effect of autophagy in human tongue squamous cell carcinoma SCC 25 cells from Scutellariae Radix by ethanol extract)

  • 최별보라
    • 한국치위생학회지
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    • 제14권2호
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    • pp.287-292
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    • 2014
  • Objectives : The purpose of the study is to examine the cell growth effect and autophagy effect of Scutellariae Radix by ethanol extract in SCC 25 cells. Methods : Cell growth inhibitory effect and autophagy induced by Scutellariae Radix were confirmed by WST-1 assay, monodansylcadaverine(MDC) stain, and flow cytometry by acridine orange(AO) stain. Results : The Scutellariae Radix treatment decreased the cell proliferation in a dose and time dependent manner. Scutellariae Radix has anticancer effects that autophagic vacuoles were apparent by MDC and AO staining in SCC 25 cells. Conclusions : Scutellariae Radix showed anticancer activity against SCC 25 cells via autophagy. The data provided the possibility that Scutellariae Radix may potentially contribute to oral cancer treatment.

ESCRT, autophagy, and frontotemporal dementia

  • Lee, Jin-A;Gao, Fen-Biao
    • BMB Reports
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    • 제41권12호
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    • pp.827-832
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    • 2008
  • Many age-dependent neurodegenerative diseases are associated with the accumulation of abnormally folded proteins within neurons. One of the major proteolytic pathways in the cell is the autophagy pathway, which targets cytoplasmic contents and organelles to the lysosomes for bulk degradation under various physiological and stressful conditions. Although the importance of autophagy in cellular physiology is well appreciated, its precise roles in neurodegeneration remain largely unclear. Recent studies indicate that components of the endosomal sorting complex required for transport (ESCRT) are important in the autophagy pathway. Reduced activity of some ESCRT subunits leads to the accumulation of autophagosomes and failure to clear intracellular protein aggregates. Interestingly, rare mutations in CHMP2B, an ESCRT-III subunit, are associated with frontotemporal dementia linked to chromosome 3 (FTD3). Mutant CHMP2B proteins seem to disrupt the fusion of autophagosomes and lysosomes in cell culture models. These findings suggest a potential mechanism for the pathogenesis of FTD3 and possibly other neurodegenerative diseases as well.

Autophagy and its regulation by ginseng components

  • Qomaladewi, Nurinanda Prisky;Kim, Mi-Yeon;Cho, Jae Youl
    • Journal of Ginseng Research
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    • 제43권3호
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    • pp.349-353
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    • 2019
  • Autophagy is the sequential process whereby cell components are degraded, which can occur due to nutrient deprivation. Its regulation has an essential role in many diseases, functioning in both cell survival and cell death. Autophagy starts when mTORC1 is inhibited, resulting in the activation of several complexes to form a cargo that fuses with a lysosome, where it undergoes degradation. In this review, we describe a plant extract that is well known in Korea, namely Korean ginseng extract; we studied how its derivatives and metabolites can regulate autophagy and thus mediate the pathogenesis of certain diseases.

Protein and RNA Quality Control by Autophagy in Plant Cells

  • Yoon, Seok Ho;Chung, Taijoon
    • Molecules and Cells
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    • 제42권4호
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    • pp.285-291
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    • 2019
  • Eukaryotic cells use conserved quality control mechanisms to repair or degrade defective proteins, which are synthesized at a high rate during proteotoxic stress. Quality control mechanisms include molecular chaperones, the ubiquitin-proteasome system, and autophagic machinery. Recent research reveals that during autophagy, membrane-bound organelles are selectively sequestered and degraded. Selective autophagy is also critical for the clearance of excess or damaged protein complexes (e.g., proteasomes and ribosomes) and membrane-less compartments (e.g., protein aggregates and ribonucleoprotein granules). As sessile organisms, plants rely on quality control mechanisms for their adaptation to fluctuating environments. In this mini-review, we highlight recent work elucidating the roles of selective autophagy in the quality control of proteins and RNA in plant cells. Emphasis will be placed on selective degradation of membrane-less compartments and protein complexes in the cytoplasm. We also propose possible mechanisms by which defective proteins are selectively recognized by autophagic machinery.

Ataxia-Telangiectasia Mutated Is Involved in Autolysosome Formation

  • Mihwa Hwang;Dong Wha Jun;Bo Ram Song;Hanna Shim;Chang-Hun Lee;Sunshin Kim
    • Biomolecules & Therapeutics
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    • 제31권5호
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    • pp.559-565
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    • 2023
  • Ataxia-telangiectasia mutated (ATM), a master kinase of the DNA damage response (DDR), phosphorylates a multitude of substrates to activate signaling pathways after DNA double-strand breaks (DSBs). ATM inhibitors have been evaluated as anticancer drugs to potentiate the cytotoxicity of DNA damage-based cancer therapy. ATM is also involved in autophagy, a conserved cellular process that maintains homeostasis by degrading unnecessary proteins and dysfunctional organelles. In this study, we report that ATM inhibitors (KU-55933 and KU-60019) provoked accumulation of autophagosomes and p62 and restrained autolysosome formation. Under autophagy-inducing conditions, the ATM inhibitors caused excessive autophagosome accumulation and cell death. This new function of ATM in autophagy was also observed in numerous cell lines. Repression of ATM expression using an siRNA inhibited autophagic flux at the autolysosome formation step and induced cell death under autophagy-inducing conditions. Taken together, our results suggest that ATM is involved in autolysosome formation and that the use of ATM inhibitors in cancer therapy may be expanded.

Immunostimulatory Activity of Solanum nigrum Through TLR4-Mediated JNK Activation in RAW264.7 Cells

  • Ju-Hyeong Yu;So Jeong Park;Jae Won Lee;Jin Boo Jeong
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2022년도 추계학술대회
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    • pp.88-88
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    • 2022
  • In this study, we investigated the effect of Solanum nigrum aerial parts (SNAP) on macrophage activation and macrophage autophagy in RAW264.7 cells. SNAP increased the production of immunostimulatory factors and phagocytosis in RAW264.7 cells. TLR4 inhibition blocked SNAP-mediated production of immunostimulatory factors. In addition, the JNK inhibition reduced the SNAP-mediated production of immunostimulatory factors, and the SNAP-mediated JNK activation was blocked by the TLR4 inhibition. SNAP activated macrophage autophagy. TLR4 inhibition blocked SNAP-mediated macrophage autophagy and inhibition of p38 and JNK attenuated SNAP-mediated macrophage autophagy. These findings indicate that SNAP may induce TLR4/JNK-mediated macrophage activation and TLR4/p38 and JNK-mediated macrophage autophagy.

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Effects of hypoxia inducible factors-$1{\alpha}$ on autophagy and invasion of trophoblasts

  • Choi, Jong-Ho;Lee, Hyun-Jung;Yang, Tae-Hyun;Kim, Gi Jin
    • Clinical and Experimental Reproductive Medicine
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    • 제39권2호
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    • pp.73-80
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    • 2012
  • Objective: This study was undertaken to determine the effect of hypoxia inducible factor (HIF)-$1{\alpha}$ on the cell death, autophagy, and invasion of trophoblasts. Methods: To understand the effect of HIF-$1{\alpha}$, we inhibited HIF-$1{\alpha}$ using siRNA under normoxia and hypoxia conditions. Invasion assay and zymography were performed to determine changes in the invasion ability of HIF-$1{\alpha}$. Western blotting and immunofluorescence were performed to determine some of the signal events involved in apoptosis and autophagy. Results: There was no difference in cell death through the inhibition of HIF-$1{\alpha}$ expression by siRNA; however, the expression of LC3 and autophagosome formation increased. On the other hand, autophagy was increased, and the invasive ability of trophoblast cells decreased according to the inhibition of HIF-$1{\alpha}$ expression by siRNA. These experimental results mean that HIF-$1{\alpha}$ genes regulate the invasive ability of trophoblasts by increasing autophagy. Conclusion: This study contributes important data for understanding the mechanism of early pregnancy implantation and the invasive ability of trophoblasts by defining the relationship between the roles of HIF-$1{\alpha}$ and autophagy.

Polysaccharide from Polygonatum Inhibits the Proliferation of Prostate Cancer-Associated Fibroblasts Cells

  • Han, Shu-Yu;Hu, Ming-Hua;Qi, Guan-Yun;Ma, Chao-Xiong;Wang, Yuan-Yuan;Ma, Fang-Li;Tao, Ning;Qin, Zhi-Hai
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권8호
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    • pp.3829-3833
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    • 2016
  • Inhibition of cancer-associated fibroblasts (CAFs) may improve the efficacy of cancer therapy. Polysaccharide extracted from polygonatum can selectively inhibit the growth of prostate-CAFs (p<0.001) without inhibiting the growth of normal fibroblasts (NAFs). Polysaccharides from polygonatum stimulate autophagy of prostate-CAFs. 3-methyl-adenine(3-MA) is an autophagy inhibitor. 3-MA was added to prostate-CAFs with polysaccharide from polygonatum to determine whether autophagy plays an important role in the restrained effect. Finally, polysaccharide from polygonatum treatment significantly increased the activation of Beclin-1 and LC3, key autophagy proteins. Polysaccharide from polygonatum stimulates autophagy of prostate-CAFs and inhibits prostate-CAF growth, indicating that a novel anti-cancer strategy involves inhibiting the growth of prostate-CAFs.

Isolation and Identification of an Autophagy-inducing Compound from Raphani Semen

  • Gu, Ming-Yao;Kwon, Hak Cheol;Song, Min Ok;Ko, Hyeonseok;Cha, Jin-Wook;Lee, Won Jong;Yang, Hyun Ok
    • Natural Product Sciences
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    • 제19권3호
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    • pp.242-250
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    • 2013
  • The autophagy-lysosomal pathway is an important protein degradation system, and its dysfunction has been implicated in a number of neurodegenerative diseases, including Parkinson's disease. Raphani Semen, one of the herbs of Yeoldahanso-tang (YH), has neuroprotective effects via the autophagy pathway. The activity-guided method was used to isolate and identify the components of Raphani Semen. In this experiment, the total extract of Raphani Semen was partitioned to n-butanol, methylene chloride, and water fractions. Flow cytometry data showed that only the water fraction showed autophagy-inducing activity in vitro. Compounds 1 and 2 were isolated from this water fraction by preparative HPLC separation. The structures of compounds 1 and 2 were identified as stachyose and raffinose, respectively, by the analysis of various spectral data ($^1H$ NMR, $^{13}C$ NMR, and MS) and comparisons with standard stachyose and raffinose. Of these two compounds, raffinose showed autophagy-inducing activity in PC12 cells through the mTOR pathway.