• Title/Summary/Keyword: autophagy

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Regulation of UVB-induced DRAM1-Autophagy protein in HDF Cells by the Vitexin (Vitexin에 의한 HDF 세포에서 UVB 유도 DRAM1-오토파지 단백질)

  • Byun, Seo-Jung;Kang, Sang-Mo;Cho, Young Jae
    • Journal of Convergence for Information Technology
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    • v.11 no.2
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    • pp.201-210
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    • 2021
  • This study was carried out to investigate the Fagopyrum esculentum (F. esculentum) extracts and vitexin are as the results of microarray, cell proliferation, cell wound recovery, cell cycle, microphage pattern and protein analysis for damage improvement caused by UVB-induced damage. Microarray results showed that UVB-induced increase in DRAM1, Atg2a and Atg13 genes was reduced in F. esculentum ethanol extract and vitexin. Cell proliferation, wound repair, cell cycle, and microphage patterns were improved in F. esculentum ethanol extract and vitexin, while buckwheat ethanol extract and vitexin decreased in both DRAM1, Beclin-1, and LC3 I/II in the vitexin treatment group and p-mTOR and survivin were all increased in protein analysis. It is thought that it can recover to normal and control autophagy, one of the causes of cell aging caused by UVB, to inhibit and regenerate cell death. F. esculentum ethanol extract and vitexin can be used as a functional cosmetic ingredient.

Oleanolic Acid Protects the Skin from Particulate Matter-Induced Aging

  • Kim, Youn Jin;Lee, Ji Eun;Jang, Hye Sung;Hong, Sung Yun;Lee, Jun Bae;Park, Seo Yeon;Hwang, Jae Sung
    • Biomolecules & Therapeutics
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    • v.29 no.2
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    • pp.220-226
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    • 2021
  • The role of particulate matter (PM) in health problems including cardiovascular diseases (CVD) and pneumonia is becoming increasingly clear. Polycyclic aromatic hydrocarbons, major components of PM, bind to aryl hydrocarbon receptor (AhRs) and promote the expression of CYP1A1 through the AhR pathway in keratinocytes. Activation of AhRs in skin cells is associated with cell differentiation in keratinocytes and inflammation, resulting in dermatological lesions. Oleanolic acid, a natural component of L. lucidum, also has anti-inflammation, anticancer, and antioxidant characteristics. Previously, we found that PM10 induced the AhR signaling pathway and autophagy process in keratinocytes. Here, we investigated the effects of oleanolic acid on PM10-induced skin aging. We observed that oleanolic acid inhibits PM10-induced CYP1A1 and decreases the increase of tumor necrosis factor-alpha and interleukin 6 induced by PM10. A supernatant derived from keratinocytes cotreated with oleanolic acid and PM10 inhibited the release of matrix metalloproteinase 1 in dermal fibroblasts. Also, the AhR-mediated autophagy disruption was recovered by oleanolic acid. Thus, oleanolic acid may be a potential treatment for addressing PM10-induced skin aging.

Pan-Caspase Inhibitor zVAD Induces Necroptotic and Autophagic Cell Death in TLR3/4-Stimulated Macrophages

  • Chen, Yuan-Shen;Chuang, Wei-Chu;Kung, Hsiu-Ni;Cheng, Ching-Yuan;Huang, Duen-Yi;Sekar, Ponarulselvam;Lin, Wan-Wan
    • Molecules and Cells
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    • v.45 no.4
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    • pp.257-272
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    • 2022
  • In addition to inducing apoptosis, caspase inhibition contributes to necroptosis and/or autophagy depending on the cell type and cellular context. In macrophages, necroptosis can be induced by co-treatment with Toll-like receptor (TLR) ligands (lipopolysaccharide [LPS] for TLR4 and polyinosinic-polycytidylic acid [poly I:C] for TLR3) and a cell-permeable pan-caspase inhibitor zVAD. Here, we elucidated the signaling pathways and molecular mechanisms of cell death. We showed that LPS/zVAD- and poly I:C/zVAD-induced cell death in bone marrow-derived macrophages (BMDMs) was inhibited by receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 and autophagy inhibitor 3-methyladenine. Electron microscopic images displayed autophagosome/autolysosomes, and immunoblotting data revealed increased LC3II expression. Although zVAD did not affect LPS- or poly I:C-induced activation of IKK, JNK, and p38, it enhanced IRF3 and STAT1 activation as well as type I interferon (IFN) expression. In addition, zVAD inhibited ERK and Akt phosphorylation induced by LPS and poly I:C. Of note, zVAD-induced enhancement of the IRF3/IFN/STAT1 axis was abolished by necrostatin-1, while zVAD-induced inhibition of ERK and Akt was not. Our data further support the involvement of autocrine IFNs action in reactive oxygen species (ROS)-dependent necroptosis, LPS/zVAD-elicited ROS production was inhibited by necrostatin-1, neutralizing antibody of IFN receptor (IFNR) and JAK inhibitor AZD1480. Accordingly, both cell death and ROS production induced by TLR ligands plus zVAD were abrogated in STAT1 knockout macrophages. We conclude that enhanced TRIF-RIP1-dependent autocrine action of IFNβ, rather than inhibition of ERK or Akt, is involved in TLRs/zVAD-induced autophagic and necroptotic cell death via the JAK/STAT1/ROS pathway.

Inhibition of mitoNEET induces Pink1-Parkin-mediated mitophagy

  • Lee, Seunghee;Lee, Sangguk;Lee, Seon-Jin;Chung, Su Wol
    • BMB Reports
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    • v.55 no.7
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    • pp.354-359
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    • 2022
  • MitoNEET, a mitochondrial outer membrane protein containing the Asn-Glu-Glu-Thr (NEET) sequence, controls the formation of intermitochondrial junctions and confers autophagy resistance. Moreover, mitoNEET as a mitochondrial substrate undergoes ubiquitination by activated Parkin during the initiation of mitophagy. Therefore, mitoNEET is linked to the regulation of autophagy and mitophagy. Mitophagy is the selective removal of the damaged or unnecessary mitochondria, which is crucial to sustaining mitochondrial quality control. In numerous human diseases, the accumulation of damaged mitochondria by impaired mitophagy has been observed. However, the therapeutic strategy targeting of mitoNEET as a mitophagy-enhancing mediator requires further research. Herein, we confirmed that mitophagy is indeed activated by mitoNEET inhibition. CCCP (carbonyl cyanide m-chlorophenyl hydrazone), which leads to mitochondrial depolarization, induces mitochondrial dysfunction and superoxide production. This, in turn, contributes to the induction of mitophagy; mitoNEET protein levels were initially increased before an increase in LC3-II protein following CCCP treatment. Pharmacological inhibition of mitoNEET using mitoNEET Ligand-1 (NL-1) promoted accumulation of Pink1 and Parkin, which are mitophagy-associated proteins, and activation of mitochondria-lysosome crosstalk, in comparison to CCCP alone. Inhibition of mitoNEET using NL-1, or mitoNEET shRNA transfected into RAW264.7 cells, abrogated CCCP-induced ROS and mitochondrial cell death; additionally, it activated the expression of PGC-1α and SOD2, regulators of oxidative metabolism. In particular, the increase in PGC-1α, which is a major regulator of mitochondrial biogenesis, promotes mitochondrial quality control. These results indicated that mitoNEET is a potential therapeutic target in numerous human diseases to enhance mitophagy and protect cells by maintaining a network of healthy mitochondria.

High fat diet-induced brain damaging effects through autophagy-mediated senescence, inflammation and apoptosis mitigated by ginsenoside F1-enhanced mixture

  • Hou, Jingang;Jeon, Byeongmin;Baek, Jongin;Yun, Yeejin;Kim, Daeun;Chang, Boyoon;Kim, Sungyeon;Kim, Sunchang
    • Journal of Ginseng Research
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    • v.46 no.1
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    • pp.79-90
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    • 2022
  • Background: Herbal medicines are popular approaches to capably prevent and treat obesity and its related diseases. Excessive exposure to dietary lipids causes oxidative stress and inflammation, which possibly induces cellular senescence and contribute the damaging effects in brain. The potential roles of selective enhanced ginsenoside in regulating high fat diet (HFD)-induced brain damage remain unknown. Methods: The protection function of Ginsenoside F1-enhanced mixture (SGB121) was evaluated by in vivo and in vitro experiments. Human primary astrocytes and SH-SY5Y cells were treated with palmitic acid conjugated Bovine Serum Albumin, and the effects of SGB121 were determined by MTT and lipid uptake assays. For in vivo tests, C57BL/6J mice were fed with high fat diet for 3 months with or without SGB121 administration. Thereafter, immunohistochemistry, western blot, PCR and ELISA assays were conducted with brain tissues. Results and conclusion: SGB121 selectively suppressed HFD-induced oxidative stress and cellular senescence in brain, and reduced subsequent inflammation responses manifested by abrogated secretion of IL-6, IL-1β and TNFα via NF-κB signaling pathway. Interestingly, SGB121 protects against HFD-induced damage by improving mitophagy and endoplasmic reticulum-stress associated autophagy flux and inhibiting apoptosis. In addition, SGB121 regulates lipid uptake and accumulation by FATP4 and PPARα. SGB121 significantly abates excessively phosphorylated tau protein in the cortex and GFAP activation in corpus callosum. Together, our results suggest that SGB121 is able to favor the resistance of brain to HFD-induced damage, therefore provide explicit evidence of the potential to be a functional food.

Hydrogen sulfide ameliorates abdominal aorta coarctation-induced myocardial fibrosis by inhibiting pyroptosis through regulating eukaryotic translation initiation factor 2α phosphorylation and activating PI3K/AKT1 pathway

  • Yaling Li;Zhixiong Wu;Jiangping Hu;Gongli Liu;Hongming Hu;Fan Ouyang;Jun Yang
    • The Korean Journal of Physiology and Pharmacology
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    • v.27 no.4
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    • pp.345-356
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    • 2023
  • This study aimed to assess the effects of exogenous hydrogen sulfide (H2S) on abdominal aorta coarctation (AAC) induced myocardial fibrosis (MF) and autophagy in rats. Forty-four Sprague-Dawley rats were randomly divided into control group, AAC group, AAC + H2S group, and H2S control group. After a model of rats with AAC was built surgically, AAC + H2S group and H2S group were injected intraperitoneally with H2S (100 µmol/kg) daily. The rats in the control group and the AAC group were injected with the same amount of PBS. We observed that H2S can improve left ventricular function and the deposition of myocardial collagen fibers, inhibit pyroptosis, down-regulate the expression of P-eif2α in myocardial tissue, and inhibit cell autophagy by activating the phosphatidylinositol 3-kinase (PI3K)/AKT1 signaling pathway (p < 0.05). In addition, angiotensin II (1 µM) H9c2 cardiomyocytes were injured in vitro experiments, and it was also observed that pyroptosis was inhibited after H2S (400 µmol/kg) intervention, the expression of P-eif2α in cardiomyocytes was significantly down-regulated, and the PI3K/AKT1 signaling pathway was activated at the same time. Therefore, increasing the expression of P-eif2α reverses the activation of the PI3K/AKT1 signaling pathway by H2S. In conclusion, these findings suggest that exogenous H2S can ameliorate MF in rats with AAC by inhibiting pyroptosis, and the mechanism may be associated with inhibiting the phosphorylation of eif2α and activating the PI3K/AKT1 signaling pathway to inhibit excessive cell autophagy.

Therapeutic Effects of (+)-Afzelechin on Particulate Matter-Induced Pulmonary Injury

  • Sanghee Cho;Yun Jin Park;Jong-Sup Bae
    • Biomolecules & Therapeutics
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    • v.32 no.1
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    • pp.162-169
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    • 2024
  • Particulate matter (PM) constitutes a hazardous blend of organic and inorganic particles that poses health risks. Inhalation of fine airborne PM with a diameter of ≤ 2.5 ㎛ (PM2.5) can lead to significant lung impairments. (+)-afzelechin (AZC), a natural compound sourced from Bergenia ligulata, boasts a range of attributes, including antioxidant, antimicrobial, anticancer, and cardiovascular effects. However, knowledge about the therapeutic potential of AZC for patients with PM2.5-induced lung injuries remains limited. Thus, in this study, we investigated the protective attributes of AZC against lung damage caused by PM2.5 exposure. AZC was administered to the mice 30 min after intratracheal instillation of PM2.5. Various parameters, such as changes in lung tissue wet/dry (W/D) weight ratio, total protein/total cell ratio, lymphocyte counts, levels of inflammatory cytokines in bronchoalveolar lavage fluid (BALF), vascular permeability, and histology, were evaluated in mice exposed to PM2.5. Data demonstrated that AZC mitigated lung damage, reduced W/D weight ratio, and curbed hyperpermeability induced by PM2.5 exposure. Furthermore, AZC effectively lowered plasma levels of inflammatory cytokines produced by PM2.5 exposure. It reduced the total protein concentration in BALF and successfully alleviated PM2.5-induced lymphocytosis. Additionally, AZC substantially diminished the expression levels of Toll-like receptors 4 (TLR4), MyD88, and autophagy-related proteins LC3 II and Beclin 1. In contrast, it elevated the protein phosphorylation of the mammalian target of rapamycin (mTOR). Consequently, the anti-inflammatory attribute of AZC positions it as a promising therapeutic agent for mitigating PM2.5-induced lung injuries by modulating the TLR4-MyD88 and mTOR-autophagy pathways.

Involvement of ROS in Curcumin-induced Autophagic Cell Death

  • Lee, Youn-Ju;Kim, Nam-Yi;Suh, Young-Ah;Lee, Chu-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.15 no.1
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    • pp.1-7
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    • 2011
  • Many anticancer agents as well as ionizing radiation have been shown to induce autophagy which is originally described as a protein recycling process and recently reported to play a crucial role in various disorders. In HCT116 human colon cancer cells, we found that curcumin, a polyphenolic phytochemical extracted from the plant Curcuma longa, markedly induced the conversion of microtubule-associated protein 1 light chain 3 (LC3)-I to LC3-II and degradation of sequestome-1 (SQSTM1) which is a marker of autophagosome degradation. Moreover, we found that curcumin caused GFP-LC3 formation puncta, a marker of autophagosome, and decrease of GFP-LC3 and SQSTM1 protein level in GFP-LC3 expressing HCT116 cells. It was further confirmed that treatment of cells with hydrogen peroxide induced increase of LC3 conversion and decrease of GFP-LC3 and SQSTM1 levels, but these changes by curcumin were almost completely blocked in the presence of antioxidant, N-acetylcystein (NAC), indicating that curcumin leads to reactive oxygen species (ROS) production, which results in autophagosome development and autolysosomal degradation. In parallel with NAC, SQSTM1 degradation was also diminished by bafilomycin A, a potent inhibitor of autophagosome-lysosome fusion, and cell viability assay was further confirmed that cucurmin-induced cell death was partially blocked by bafilomycin A as well as NAC. We also observed that NAC abolished curcumin-induced activation of extracelluar signal-regulated kinases (ERK) 112 and p38 mitogen-activated protein kinases (MAPK), but not Jun N-terminal kinase (JNK). However, the activation of ERK1/2 and p38 MAPK seemed to have no effect on the curcumin-induced autophagy, since both the conversion of LC3 protein and SQSTM1 degradation by curcumin was not changed in the presence of NAC. Taken together, our data suggest that curcumin induced ROS production, which resulted in autophagic activation and concomitant cell death in HCT116 human colon cancer cell. However, ROS-dependent activation of ERK1/2 and p38 MAPK, but not JNK, might not be involved in the curcumin-induced autophagy.

Potentiation of the Cytotoxic Effects of Imatinib and TRAIL by Nonsteroidal Anti-inflammatory Drugs on Human Cancer Cells (비스테로이드소염제(Nonsteroidal Anti-inflammatory Drug, NSAID)에 의한 인간 암세포의 imatinib 및 TRAIL의 세포 독성 증강 기전 연구)

  • Moon, Hyun-Jung;Kang, Chi-Dug;Kim, Sun-Hee
    • Journal of Life Science
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    • v.30 no.8
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    • pp.661-671
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    • 2020
  • The resistance of cancer cells to anti-cancer drugs is the leading cause of chemotherapy failure. The clinical use of nonsteroidal anti-inflammatory drugs (NSAIDs) has been gradually extended to cancer treatment through combination with anti-cancer drugs. In the current study, we investigated whether NSAIDs including celecoxib (CCB), 2,5-dimethyl celecoxib (DMC), and ibuprofen (IBU) could enhance the cytotoxic effects of imatinib and TNF-related apoptosis inducing ligand (TRAIL) on human cancer cells. We found that the NSAIDs potentiated TRAIL and imatinib cytotoxicity against human hepatocellular carcinoma (HCC) cell lines SNU-354, SNU-423, SNU-449, and SNU-475/TR and against leukemic K562 cells with high level of CD44 (CD44highK562), respectively. More specifically, CCB induced endoplasmic reticulum stress via up-regulation of ATF4/CHOP which is associated with the induction of autophagy against HCC and CD44high K562 cells. NSAID-induced autophagic activity accelerated TRAIL cytotoxicity of HCC cells through up- and down-regulation of DR5 and c-FLIP, respectively. The NSAIDs also potentiated imatinib-induced cytotoxicity and apoptosis through down-regulation of markers in CD44highK562 cells that express a stemness phenotype. Our results suggest that the ability of NSAIDs to induce autophagy could enhance the cytotoxicity of TRAIL and imatinib, leading to a reverse resistance to these drugs in the cancer cells. In conclusion, NSAIDs in combination with low-dose TRAIL or imatinib may constitute a novel clinical strategy that maximizes therapeutic efficacy of each drug and effectively reduces the toxic side effects.

Effects of Cortisol on Endoplasmic Reticulum-stress, Apoptosis, and Autophagy in Mouse Muscle C2C12 Cells (생쥐 근육세포에서 코티졸이 세포질세망 스트레스, 자연 세포사멸과 자가포식에 미치는 영향)

  • Shin, Donghyun;Kim, Kyoung Hwan;Lee, Ji Hyun;Cho, Byung-Wook
    • Journal of Life Science
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    • v.28 no.10
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    • pp.1127-1131
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    • 2018
  • Cortisol, a steroid hormone, functions within metabolism, immune response, and stress. Intense or prolonged physical exercise increases cortisol levels to enhance the gluconeogenesis pathway and stabilize blood glucose level. However, cortisol also exerts a negative impact on muscle function and creates a stressful environment in skeletal muscle cells. The present study investigated the function of cortisol as a stress hormone. To examine the effect of the exercise-induced hormone cortisol on skeletal muscles, C2C12 cells were cultured and treated with cortisol at different concentrations. As a result, we found that the morphology of C2C12 changed remarkably with 5 ug/ml cortisol treatment. Western blot analysis was conducted to learn whether ER-stress and autophagy were induced. We found that the expression ratio of LC3I/LC3II decreased and BiP expression increased after cortisol treatment. In addition, immunocytochemistry analysis with IER3 antibody clearly showed that apoptosis is induced after 12-hour cortisol treatment. These results indicate that cortisol treatment could induce apoptosis, ER-stress, and autophagy in muscle cells. This study would provide valuable information in the study of the effects of exercise on skeletal muscle cells and the development of additives to reduce cortisol stress.