• Title/Summary/Keyword: autophagy

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Repopulation of autophagy-deficient stromal cells with autophagy-intact cells after repeated breeding in uterine mesenchyme-specific Atg7 knockout mice

  • Ji-Eun Oh;Sojung Kwon;Hyunji Byun;Haengseok Song;Hyunjung Jade Lim
    • Clinical and Experimental Reproductive Medicine
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    • v.50 no.3
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    • pp.170-176
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    • 2023
  • Objective: Autophagy is highly active in ovariectomized mice experiencing hormone deprivation, especially in the uterine mesenchyme. Autophagy is responsible for the turnover of vasoactive factors in the uterus, which was demonstrated in anti-Müllerian hormone receptor type 2 receptor (Amhr2)-Cre-driven autophagy-related gene 7 (Atg7) knockout (Amhr-Cre/Atg7f/f mice). In that study, we uncovered a striking difference in the amount of sequestosome 1 (SQSTM1) accumulation between virgin mice and breeder mice with the same genotype. Herein, we aimed to determine whether repeated breeding changed the composition of mesenchymal cell populations in the uterine stroma. Methods: All female mice used in this study were of the same genotype. Atg7 was deleted by Amhr2 promoter-driven Cre recombinase in the uterine stroma and myometrium, except for a triangular stromal region on the mesometrial side. Amhr-Cre/Atg7f/f female mice were divided into two groups: virgin mice with no mating history and aged between 11 and 12 months, and breeder mice with at least 6-month breeding cycles with multiple pregnancies and aged around 12 months. The uteri were used for Western blotting and immunofluorescence staining. Results: SQSTM1 accumulation, representing Atg7 deletion and halted autophagy, was much higher in virgin mice than in breeders. Breeders showed reduced accumulation of several vasoconstrictive factors, which are potential autophagy targets, in the uterus, suggesting that the uterine stroma was repopulated with autophagy-intact cells during repeated pregnancies. Conclusion: Multiple pregnancies seem to have improved the uterine environment by replacing autophagy-deficient cells with autophagy-intact cells, providing evidence of cell mixing.

Overview of Autophagy in Plant Cells (식물 세포의 자식작용에 대한 개요)

  • Lee, Han Nim;Chung, Taijoon
    • Journal of Life Science
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    • v.24 no.2
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    • pp.209-217
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    • 2014
  • In a variety of eukaryotic cells, autophagy sequesters a portion of the cytoplasm and targets it to a lytic compartment for degradation in bulk. Autophagy is a dynamic process for degrading cytoplasmic cargoes with various degrees of selectivity, and its activity is tightly regulated in a nutrient- and development-dependent manner. Autophagy research has drawn much attention since autophagy not only is an interesting cell biological phenomenon but also has great potential for medical and agricultural applications. For example, autophagy is associated with cancers and neurodegenerative diseases in human and mammalian cells and is also suggested in remobilization of nutrients during the senescence of plant leaves. In this general review, we describe genetic components of the core autophagic machinery conserved among yeast, animals, and plants and briefly explain how these components are responsible for major steps in plant autophagy. We discuss four common features of autophagic processes: (i) autophagy as a degradation pathway, (ii) the concept of flux in autophagy research, (iii) dependency on developmental and nutritional cues, and (iv) diversity of autophagy, focusing on selective types of autophagy. We also summarize cell biological and physiological functions of plant autophagy. Our intention is to provide a quick guide to autophagy for those who are new to autophagy research.

Effects of Platycodon grandiflorum on the Induction of Autophagy and Apoptosis in HCT-116 Human Colon Cancer Cells (길경 추출물에 의한 HCT-116 대장암 세포주에서의 autophagy와 apoptosis 유발 효과)

  • Hong, Su Hyun;Park, Cheol;Han, Min Ho;Kim, Hong Jae;Lee, Moon Hee;Choi, Yung Hyun
    • Journal of Life Science
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    • v.24 no.11
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    • pp.1244-1251
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    • 2014
  • Platycodon grandiflorum (PG) has been known to possess many biological effects, including anti-inflammatory and anti-allergy activity and anti-obesity and hyperlipidemia effects. However, little research has been conducted regarding its anticancer effects, with the exception of its ability to stimulate apoptosis in skin cells. There has also been no study regarding PG-induced autophagy. The modulation of autophagy is recognized as one of the hallmarks of cancer cells. Depending on the type of cancer and the context, autophagy can suppress or help cancer cells to overcome metabolic stress and the cytotoxicity of chemotherapy. Therefore, the present study was designed to investigate whether or not extracts from PG-induced cell death were connected with autophagy and apoptosis in HCT-116 human colon cancer cells. PG stimulation decreased cell proliferation in a dose- and time-dependent manner and induced apoptosis, which was partially dependent on the activation of caspases. PG treatment also resulted in the formation of autophagic vacuoles simultaneously with regulation of autophagy-related genes. Interestingly, a PG-mediated apoptotic effect was further triggered by pretreatment with the autophagy inhibitors 3-methyladenin and bafilomycin A1. However, cell viability recovered quite well with bafilomycin A1 treatment. These findings show that PG treatment promotes both autophagy and apoptosis and that PG-induced autophagic response might play a role in the autophagic cell death of HCT-116 cells.

Review of Herb Related Papers on Anticancer Effects through Autophagy (자가포식을 통한 항암효과에 대한 한약 관련 논문 분석)

  • Li, Kuo-Chu;Kim, Kyung-Soon;Yoo, Hwa-Seung;Lee, Yeon-Weol;Cho, Chong-Kwan
    • Journal of Haehwa Medicine
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    • v.20 no.2
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    • pp.91-98
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    • 2012
  • Objective : This is a comprehensive review summary of anticancer effect through autophagy using herb. Method : Data were retrieved from pubmed and authorized texts concerning anticancer effect through autophagy using herb.g its ant Results : A total of 5 potentially relevant studies were identified with including 4 in vitro papers. All papers were related to single herb extract or its compound providini-cancer effect through autophagy mechanisms of up-regulated pro-autophagy proteins and down-regulated anti-autophagy proteins. Conclusion : We can search five potentially relevant studies with anticancer treatment through enhancing autophagy mechanism. Autophagy will be a good pathway mechanism to explore novel experimental therapeutics in herb.

Autophagy Inhibition Promotes Quercetin Induced Apoptosis in MG-63 Human Osteosarcoma cells

  • Park, Sung-Jin;Yu, Su-Bin;Kim, Yong-Ho;Kim, In-Ryoung;Park, Hae-Ryoun;Park, Bong-Soo
    • International Journal of Oral Biology
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    • v.40 no.2
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    • pp.85-91
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    • 2015
  • Quercetin is a natural flavonoid phytochemical that is extracted from various plants. Having an advantages due to its varied biological properties, such as anti-inflammatory, anti-viral, anti-oxidant, and anti-cancer effects, quercetin is used to treat many diseases. Recently, it has been reported that autophagy inhibition may play a key role in anti-cancer therapy. Therefore, in this study, we investigated the molecular mechanisms and anti-cancer effects of quercetin in human osteosarcoma cells via autophagy inhibition. We ascertained that quercetin inhibited cell proliferation and induced cell death, these process is demonstrated that apoptosis via the mitochondrial pathway and the caspase cascade. Quercetin also induced autophagy which was inhibited by 3-MA, autophagy inhibitor and the blockade of autophagy promoted the quercetin-induced apoptosis, confirming that autophagy is a pro-survival process. Thus, these findings demonstrate that quercetin is an effective anti-cancer agent, and the combination of quercetin and an autophagy inhibitor should enhance the effect of anti-cancer therapy.

A Revised Assay for Monitoring Autophagic Flux in Arabidopsis thaliana Reveals Involvement of AUTOPHAGY-RELATED9 in Autophagy

  • Shin, Kwang Deok;Lee, Han Nim;Chung, Taijoon
    • Molecules and Cells
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    • v.37 no.5
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    • pp.399-405
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    • 2014
  • Autophagy targets cytoplasmic cargo to a lytic compartment for degradation. Autophagy-related (Atg) proteins, including the transmembrane protein Atg9, are involved in different steps of autophagy in yeast and mammalian cells. Functional classification of core Atg proteins in plants has not been clearly confirmed, partly because of the limited availability of reliable assays for monitoring autophagic flux. By using proUBQ10-GFP-ATG8a as an autophagic marker, we showed that autophagic flux is reduced but not completely compromised in Arabidopsis thaliana atg9 mutants. In contrast, we confirmed full inhibition of auto-phagic flux in atg7 and that the difference in autophagy was consistent with the differences in mutant phenotypes such as hypersensitivity to nutrient stress and selective autophagy. Autophagic flux is also reduced by an inhibitor of phosphatidylinositol kinase. Our data indicated that atg9 is phenotypically distinct from atg7 and atg2 in Arabidopsis, and we proposed that ATG9 and phosphatidylinositol kinase activity contribute to efficient autophagy in Arabidopsis.

Influence of Autophagy Induction after Hormone Treatment on Oocytes Maturation of Porcine

  • Kim, Sang Hwan;Yoon, Jong Taek
    • Journal of Embryo Transfer
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    • v.33 no.4
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    • pp.271-280
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    • 2018
  • Here, we evaluated the mode of programmed cell death during porcine oocyte maturation by comparing the two major pathways associated with programmed cell death, apoptosis (type I), and autophagy (type II). We investigated the expression and localization of major genes involved in autophagy and apoptosis at mRNA and protein levels. Furthermore, the effect of hormonal stimulation on autophagy and apoptosis was analyzed. We found that the activity of autophagy-associated genes was increased in the cumulus-oocyte complexes (COCs) following follicle-stimulating hormone (FSH) treatment, while the addition of luteinizing hormone (LH) reversed this effect. The expression of proteins associated with autophagy was the highest in FSH-treated COCs. On the other hand, caspase-3 protein level was maximum in COCs cultured with LH. The treatment with rapamycin resulted in the effect similar to that observed with FSH treatment and increased autophagy activity. Thus, hormonal stimulation of pig oocytes resulted in distinct patterns of maturation. The high-quality oocytes majorly relied on the type II pathway (autophagy), while the type I pathway (apoptosis) was more prominent among poor-quality oocytes. Further investigation of this distinction may allow the development of techniques to produce high-quality oocytes in porcine in vitro fertilization.

Impaired Autophagic Flux in Glucose-Deprived Cells: An Outcome of Lysosomal Acidification Failure Exacerbated by Mitophagy Dysfunction

  • Eun Seong Hwang;Seon Beom Song
    • Molecules and Cells
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    • v.46 no.11
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    • pp.655-663
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    • 2023
  • Autophagy dysfunction is associated with human diseases and conditions including neurodegenerative diseases, metabolic issues, and chronic infections. Additionally, the decline in autophagic activity contributes to tissue and organ dysfunction and aging-related diseases. Several factors, such as down-regulation of autophagy components and activators, oxidative damage, microinflammation, and impaired autophagy flux, are linked to autophagy decline. An autophagy flux impairment (AFI) has been implicated in neurological disorders and in certain other pathological conditions. Here, to enhance our understanding of AFI, we conducted a comprehensive literature review of findings derived from two well-studied cellular stress models: glucose deprivation and replicative senescence. Glucose deprivation is a condition in which cells heavily rely on oxidative phosphorylation for ATP generation. Autophagy is activated, but its flux is hindered at the autolysis step, primarily due to an impairment of lysosomal acidity. Cells undergoing replicative senescence also experience AFI, which is also known to be caused by lysosomal acidity failure. Both glucose deprivation and replicative senescence elevate levels of reactive oxygen species (ROS), affecting lysosomal acidification. Mitochondrial alterations play a crucial role in elevating ROS generation and reducing lysosomal acidity, highlighting their association with autophagy dysfunction and disease conditions. This paper delves into the underlying molecular and cellular pathways of AFI in glucose-deprived cells, providing insights into potential strategies for managing AFI that is driven by lysosomal acidity failure. Furthermore, the investigation on the roles of mitochondrial dysfunction sheds light on the potential effectiveness of modulating mitochondrial function to overcome AFI, offering new possibilities for therapeutic interventions.

Can Hinokitiol Kill Cancer Cells? Alternative Therapeutic Anticancer Agent via Autophagy and Apoptosis (Hinokitiol에 의해 유도된 Autophagy 및 Apoptosis에 의한 대체 항암요법 연구)

  • Lee, Tae Bok;Jun, Jin Hyun
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.2
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    • pp.221-234
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    • 2019
  • Cancer is genetically, metabolically and infectiously induced life threatening disorder showing aggressive growing pattern with invasive tendency. In order to prevent this global menace from jeopardizing human life, enormous studies on carcinogenesis and treatment for chemotherapy resistance have been intensively researched. Hinokitiol (${\beta}$-thujaplicin) extracted from heart wood of cupressaceous is a well-known bioactive compound demonstrating anti-inflammation, anti-bacteria and anti-cancer effects on several cancer types via apoptosis and autophagy. This study proposed that hinokitiol activates transcription factor EB (TFEB) nuclear translocation for autophagy and lysosomal biogenesis regardless of nutrient condition in cancer cells. Mitophagy and ${\beta}$-catenin translocation into the nucleus under treatment of hinokitiol on non-small cell lung cancer (NSCLC) cells and HeLa cells were investigated. Hinokitiol exerted cytotoxicity on HeLa and HCC827 cells; moreover, artificially induced autophagy by overexpression of TFEB granted imperfect sustainability onto HeLa cells. Taken together, hinokitiol is the prominent autophagy inducer and activator of TFEB nuclear translocation. Alternative cancer therapy via autophagy is pros and cons since the autophagy in cancer cells is related to prevention and survival mechanism depending on nutrition. To avoid paradox of autophagy in cancer therapy, fine-tuned regulation and application of hinokitiol in due course for successful suppressing cancer cells are recommended.

Anti-apoptotic effects of autophagy via ROS regulation in microtubule-targeted and PDGF-stimulated vascular smooth muscle cells

  • Park, Hyun-Soo;Han, Joo-Hui;Jung, Sang-Hyuk;Lee, Do-Hyung;Heo, Kyung-Sun;Myung, Chang-Seon
    • The Korean Journal of Physiology and Pharmacology
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    • v.22 no.3
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    • pp.349-360
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    • 2018
  • Autophagy has been studied as a therapeutic strategy for cardiovascular diseases. However, insufficient studies have been reported concerning the influence of vascular smooth muscle cells (VSMCs) through autophagy regulation. The aim of the present study was to determine the effects of VSMCs on the regulation of autophagy under in vitro conditions similar to vascular status of the equipped micro-tubule target agent-eluting stent and increased release of platelet-derived growth factor-BB (PDGF-BB). Cell viability and proliferation were measured using MTT and cell counting assays. Immunofluorescence using an $anti-{\alpha}-tubulin$ antibody was performed to determine microtubule dynamic formation. Cell apoptosis was measured by cleavage of caspase-3 using western blot analysis, and by nuclear fragmentation using a fluorescence assay. Autophagy activity was assessed by microtubule-associated protein light chain 3-II (LC-II) using western blot analysis. Levels of intracellular reactive oxygen species (ROS) were measured using $H_2DCFDA$. The proliferation and viability of VSMCs were inhibited by microtubule regulation. Additionally, microtubule-regulated and PDGF-BB-stimulated VSMCs increased the cleavage of caspase-3 more than only the microtubule-regulated condition, similar to that of LC3-II, implying autophagy. Inhibitory autophagy of microtubule-regulated and PDGF-BB-stimulated VSMCs resulted in low viability. However, enhancement of autophagy maintained survival through the reduction of ROS. These results suggest that the apoptosis of conditioned VSMCs is decreased by the blocking generation of ROS via the promotion of autophagy, and proliferation is also inhibited. Thus, promoting autophagy as a therapeutic target for vascular restenosis and atherosclerosis may be a good strategy.