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Daneshpazhouh H, Hayati Roodbari N, Tahamtani Y, Khodabandeh Z, Dianatpour M. Protective Effect of Docetaxel Against Autophagy-Related Genes in Vitrification of Mouse Metaphase II Oocytes. IRANIAN JOURNAL OF MEDICAL SCIENCES 2023; 48:501-509. [PMID: 37786462 PMCID: PMC10541544 DOI: 10.30476/ijms.2023.88390.2811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 01/10/2023] [Accepted: 01/21/2023] [Indexed: 10/04/2023]
Abstract
Background Autophagy is a conservative mechanism for cell survival as the main response of cells to stress conditions. The present study aimed to assess the effect of docetaxel on the survival, fertilization, and expression of autophagy-related genes in vitrified oocytes. Methods The study was conducted in 2018 at the Stem Cells Technology Research Center, Shiraz University of Medical Sciences (Shiraz, Iran). Denuded oocytes were randomly selected and assigned to five groups, namely control (n=133), docetaxel (n=136), docetaxel+cryoprotectants (n=146), docetaxel+vitrification (n=138), and vitrification (n=145). The effect of vitrification on the expression of autophagy-related gene 5 (ATG5) and Beclin-1 was determined using a real-time polymerase chain reaction. Data were analyzed using SPSS software (version 26.0) and GraphPad Prism 9. Results Survival and fertilization rates in each experimental group were significantly reduced compared to the control group (P=0.001). After in vitro fertilization of oocytes, the 2-cell formation rate was significantly reduced in the docetaxel+vitrification and vitrification groups compared to the control and docetaxel groups (P=0.001 and P=0.001, respectively). Pre-incubation of oocytes with docetaxel reduced gene expression levels of Beclin-1 and ATG5 in the docetaxel+cryoprotectants and docetaxel+vitrification groups (P=0.001 and P=0.019, respectively). The expression level of these genes was also reduced in the docetaxel group compared to the control group (P=0.001). Conclusion Incubation of mouse metaphase II oocytes with docetaxel prior to vitrification reduced the expression of autophagy-related genes and increased survival and fertilization rates compared to untreated oocytes.
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Affiliation(s)
- Hamed Daneshpazhouh
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nasim Hayati Roodbari
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Yaser Tahamtani
- Department of Stem Cells and Developmental Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Zahra Khodabandeh
- Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mehdi Dianatpour
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
- Stem Cells Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Okusha Y, Murshid A, Calderwood SK. Proteotoxic stress-induced autophagy is regulated by the NRF2 pathway via extracellular vesicles. Cell Stress Chaperones 2023; 28:167-175. [PMID: 36773174 PMCID: PMC10050656 DOI: 10.1007/s12192-023-01326-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 01/17/2023] [Accepted: 01/24/2023] [Indexed: 02/12/2023] Open
Abstract
Protein homeostasis involves a number of overlapping mechanisms, including the autophagy program, that can lead to the resolution of protein damage. We aimed in this study to examine mechanisms of autophagy in the proteotoxic stress response. We found that such stress results in a rapid elevation in the rate of autophagy in mammalian cells. Induction of this process occurred coincidentally with the increased release of extracellular vesicles (EVs) into the extracellular microenvironment. We next found that purified EVs that had been released from stressed cells were capable of directly increasing autophagic flux in recipient cells. The EVs contained a range of cargo proteins, including HSP70, BAG3, and activated transcription factor phospho-NRF2 (pNRF2). NRF2 regulates the activation of both the oxidative stress response and autophagy genes. Both heat shock and exposure of cells to proteotoxic stress-induced EVs increased the intracellular levels of pNRF2 in cells. Heat shock-induced proteotoxicity also led to increases in the levels of proteins in the oxidative stress response, including HO-1 and NQO1, as well as the key autophagy proteins LC3, ATG5, and ATG7, known to be regulated by NRF2. Increases in these autophagy proteins were dependent on the expression of NRF2 and were ablated by NRF2 knockdown.
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Affiliation(s)
- Yuka Okusha
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, East Campus DA-717A, Boston, MA, 02215, USA.
- JSPS Overseas research Fellow, Tokyo, Japan.
| | - Ayesha Murshid
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, East Campus DA-717A, Boston, MA, 02215, USA
| | - Stuart K Calderwood
- Department of Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Avenue, East Campus DA-717A, Boston, MA, 02215, USA.
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Yao Q, Wu X, Tao C, Gong W, Chen M, Qu M, Zhong Y, He T, Chen S, Xiao G. Osteoarthritis: pathogenic signaling pathways and therapeutic targets. Signal Transduct Target Ther 2023; 8:56. [PMID: 36737426 PMCID: PMC9898571 DOI: 10.1038/s41392-023-01330-w] [Citation(s) in RCA: 480] [Impact Index Per Article: 240.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/06/2023] [Accepted: 01/17/2023] [Indexed: 02/05/2023] Open
Abstract
Osteoarthritis (OA) is a chronic degenerative joint disorder that leads to disability and affects more than 500 million population worldwide. OA was believed to be caused by the wearing and tearing of articular cartilage, but it is now more commonly referred to as a chronic whole-joint disorder that is initiated with biochemical and cellular alterations in the synovial joint tissues, which leads to the histological and structural changes of the joint and ends up with the whole tissue dysfunction. Currently, there is no cure for OA, partly due to a lack of comprehensive understanding of the pathological mechanism of the initiation and progression of the disease. Therefore, a better understanding of pathological signaling pathways and key molecules involved in OA pathogenesis is crucial for therapeutic target design and drug development. In this review, we first summarize the epidemiology of OA, including its prevalence, incidence and burdens, and OA risk factors. We then focus on the roles and regulation of the pathological signaling pathways, such as Wnt/β-catenin, NF-κB, focal adhesion, HIFs, TGFβ/ΒΜP and FGF signaling pathways, and key regulators AMPK, mTOR, and RUNX2 in the onset and development of OA. In addition, the roles of factors associated with OA, including MMPs, ADAMTS/ADAMs, and PRG4, are discussed in detail. Finally, we provide updates on the current clinical therapies and clinical trials of biological treatments and drugs for OA. Research advances in basic knowledge of articular cartilage biology and OA pathogenesis will have a significant impact and translational value in developing OA therapeutic strategies.
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Affiliation(s)
- Qing Yao
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Xiaohao Wu
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Chu Tao
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Weiyuan Gong
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Mingjue Chen
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Minghao Qu
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Yiming Zhong
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Tailin He
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Sheng Chen
- Department of Orthopaedics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Guozhi Xiao
- Department of Biochemistry, School of Medicine, Shenzhen Key Laboratory of Cell Microenvironment, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Southern University of Science and Technology, Shenzhen, 518055, China.
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Contextualizing Autophagy during Gametogenesis and Preimplantation Embryonic Development. Int J Mol Sci 2021; 22:ijms22126313. [PMID: 34204653 PMCID: PMC8231133 DOI: 10.3390/ijms22126313] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 01/05/2023] Open
Abstract
Mammals face environmental stressors throughout their lifespan, which may jeopardize cellular homeostasis. Hence, these organisms have acquired mechanisms to cope with stressors by sensing, repairing the damage, and reallocating resources to increase the odds of long-term survival. Autophagy is a pro-survival lysosome-mediated cytoplasm degradation pathway for organelle and macromolecule recycling. Furthermore, autophagy efflux increases, and this pathway becomes idiosyncratic depending upon developmental and environmental contexts. Mammalian germ cells and preimplantation embryos are attractive models for dissecting autophagy due to their metastable phenotypes during differentiation and exposure to varying environmental cues. The aim of this review is to explore autophagy during mammalian gametogenesis, fertilization and preimplantation embryonic development by contemplating its physiological role during development, under key stressors, and within the scope of assisted reproduction technologies.
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Li X, Sun L, Yan G, Yan X. PFKP facilitates ATG4B phosphorylation during amino acid deprivation-induced autophagy. Cell Signal 2021; 82:109956. [PMID: 33607258 DOI: 10.1016/j.cellsig.2021.109956] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 01/29/2021] [Accepted: 02/13/2021] [Indexed: 12/09/2022]
Abstract
ATG4B facilitates autophagy by promoting autophagosome maturation through the reversible lipidation and delipidation of LC3. Recent reports have shown that phosphorylation of ATG4B regulates its activity and LC3 processing, leading to modulate autophagy activity. However, the mechanism about how ATG4B phosphorylation is involved in amino acid deprivation-induced autophagy is unclear. Here, we combined the tandem affinity purification with mass spectrometry (MS) and identified the ATG4B-interacting proteins including its well-known partner gamma-aminobutyric acid receptor-associated protein (GABARAP, a homolog of LC3) and phosphofructokinase 1 platelet isoform (PFKP). Further immunoprecipitation assays showed that amino acid deprivation strengthened the interaction between ATG4B and PFKP. By genetic depletion of PFKP using CRISPR/Cas9, we uncovered that PFKP loss reduced the degradation of LC3-II and p62 due to a partial block in autophagic flux. Furthermore, MS analysis of Flag-tagged ATG4B immunoprecipitates identified phosphorylation of ATG4B serine 34 residue (S34) and PFKP serine 386 residue (S386) under amino acid deprivation condition. In vitro kinase assay validated that PFKP functioning as a protein kinase phosphorylated ATG4B at S34. This phosphorylation could enhance ATG4B activity and p62 degradation. In addition, PFKP S386 phosphorylation was important to ATG4B S34 phosphorylation and autophagy in HEK293T cells. In brief, our findings describe that PFKP, a rate-limiting enzyme in the glycolytic pathway, functions as a protein kinase for ATG4B to regulate ATG4B activity and autophagy under amino acid deprivation condition.
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Affiliation(s)
- Xiuzhi Li
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Lingling Sun
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Guokai Yan
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China
| | - Xianghua Yan
- State Key Laboratory of Agricultural Microbiology, College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China; The Cooperative Innovation Center for Sustainable Pig Production, Wuhan, Hubei 430070, China; Hubei Provincial Engineering Laboratory for Pig Precision Feeding and Feed Safety Technology, Wuhan, Hubei 430070, China.
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Chen CH, Kuo SM, Tien YC, Shen PC, Kuo YW, Huang HH. Steady Augmentation of Anti-Osteoarthritic Actions of Rapamycin by Liposome-Encapsulation in Collaboration with Low-Intensity Pulsed Ultrasound. Int J Nanomedicine 2020; 15:3771-3790. [PMID: 32547027 PMCID: PMC7266395 DOI: 10.2147/ijn.s252223] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction Rapamycin has been considered as a potential treatment for osteoarthritis (OA). Drug carriers fabricated from liposomes can prolong the effects of drugs and reduce side effects of drugs. Low-intensity pulsed ultrasound (LIPUS) has been found to possess anti-OA effects. Materials and Methods The anti-osteoarthritic effects of liposome-encapsulated rapamycin (L-rapa) combined with LIPUS were examined by culture of normal and OA chondrocytes in alginate beads and further validated in OA prone Dunkin-Hartley guinea pigs. Results L-rapa with LIPUS largely up-regulated aggrecan and type II collagen mRNA in human OA chondrocytes (HOACs). L-rapa with LIPUS caused significant enhancement in proteoglycan and type II collagen production in HOACs. Large decreases in both MMP-13 and IL-6 proteins were found in the HOACs exposed to L-rapa with LIPUS. Intra-articular injection of 40 μL L-rapa at both 5 μM and 50 μM twice a week combined with LIPUS thrice a week for 8 weeks significantly increased GAGs and type II collagen in the cartilage of knee. Results on OARSI score showed that intra-articular injection of 5 μM L-rapa with LIPUS displayed the greatest anti-OA effects. Immunohistochemistry revealed that L-rapa with or without LIPUS predominantly reduced MMP-13 in vivo. The values of complete blood count and serum biochemical examinations remained in the normal ranges after the injections with or without LIPUS. These data indicated that intra-articular injection of L-rapa collaborated with LIPUS is not only effective against OA but a safe OA therapy. Conclusion Taken together, L-rapa combined with LIPUS possessed the most consistently and effectively anabolic and anti-catabolic effects in HOACs and the spontaneous OA guinea pigs. This study evidently revealed that liposome-encapsulation collaborated with LIPUS is able to reduce the effective dose and administration frequency of rapamycin and further stably reinforce its therapeutic actions against OA.
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Affiliation(s)
- Chung-Hwan Chen
- Department of Orthopedics and Orthopedic Research Center, Kaohsiung Municipal Ta-Tung Hospital and Kaohsiung Medical University Hospital, College of Medicine, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan.,Institute of Medical Science and Technology, National Sun Yat-Sen University, Kaohsiung City 80424, Taiwan
| | - Shyh Ming Kuo
- Department of Biomedical Engineering, I-Shou University, Kaohsiung City 82445, Taiwan
| | - Yin-Chun Tien
- Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan.,Department of Orthopedics, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Po-Chih Shen
- Department of Orthopedics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan
| | - Yi-Wen Kuo
- Orthopedic Research Center, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan
| | - Han Hsiang Huang
- Department of Veterinary Medicine, National Chiayi University, Chiayi City 60054, Taiwan
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Lin MW, Chen YH, Yang HB, Lin CC, Hung SY. Galantamine Inhibits Aβ 1-42-Induced Neurotoxicity by Enhancing α7nAChR Expression as a Cargo Carrier for LC3 Binding and Aβ 1-42 Engulfment During Autophagic Degradation. Neurotherapeutics 2020; 17:676-689. [PMID: 31823156 PMCID: PMC7283419 DOI: 10.1007/s13311-019-00803-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Despite Alzheimer's disease (AD) being the most common neurodegenerative disorder worldwide, no FDA-approved disease-modifying treatments have been approved for this condition since 2003. Neuronal-type alpha7 nicotinic acetylcholine receptors (α7nAChRs) play an essential role in cognitive functions, binding with extracellular β-amyloid (Aβ plaques) and inhibiting Aβ-induced neurotoxicity. α7nAChRs are impaired early in the course of AD; drugs targeting α7nAChRs are being hotly pursued as a treatment of AD. Encenicline, a partial selective agonist of α7nAChR and modulator of acetylcholine, failed in phase III trials because of gastrointestinal side effects. We, therefore, evaluated the efficacy of galantamine, a positive allosteric modulator at α7nAChRs and an acetylcholinesterase inhibitor, that has been used since 2000 as first-line treatment of mild-to-moderate dementia. This study highlights an important new benefit with galantamine. We found that galantamine inhibits Aβ1-42-induced apoptosis by activating the JNK signaling pathway, thus enhancing α7nAChR expression, and also inhibits the Akt pathway, which further increases autophagosome biogenesis and autophagy. These effects can be reproduced by α7nAChR overexpression in the absence of galantamine. Importantly, the α7 subunit protein sequence of α7nAChRs contains 3 LC3-interacting regions; our immunoprecipitation data show that α7 binds with the autophagosomal marker protein LC3. This is the first report to provide evidence showing that the cell surface receptor α7nAChR acts as a cargo carrier for LC3 binding for Aβ1-42 sequestration to autophagosomes, suggesting a novel mechanism for the neuroprotective efficacy of galantamine in AD.
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Affiliation(s)
- Ming-Wei Lin
- Department of Medical Research, E-Da Hospital/E-Da Cancer Hospital, Kaohsiung, 82445, Taiwan
- Regenerative Medicine and Cell Therapy Research Center, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan
| | - Yi-Hung Chen
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan
- Chinese Medicine Research Center, China Medical University, Taichung, 40402, Taiwan
| | - Han-Ben Yang
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan
- Department of Life Sciences, Institute of Biomedical Science, National Chung Hsing University, Taichung, 40249, Taiwan
| | - Chi Chien Lin
- Department of Life Sciences, Institute of Biomedical Science, National Chung Hsing University, Taichung, 40249, Taiwan
| | - Shih-Ya Hung
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan.
- Division of Colorectal Surgery, China Medical University Hospital, Taichung, 40447, Taiwan.
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Edosa TT, Jo YH, Keshavarz M, Park KB, Cho JH, Bae YM, Kim B, Lee YS, Han YS. TmAtg6 Plays an Important Role in Anti-Microbial Defense Against Listeria monocytogenes in the Mealworm, Tenebrio molitor. Int J Mol Sci 2020; 21:ijms21041232. [PMID: 32059408 PMCID: PMC7072900 DOI: 10.3390/ijms21041232] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 01/17/2020] [Accepted: 02/08/2020] [Indexed: 12/29/2022] Open
Abstract
Autophagy-related gene-6 (Beclin-1 in mammals) plays a pivotal role in autophagy and is involved in autophagosome formation and autolysosome maturation. In this study, we identified and characterized the autophagy-related gene-6 from Tenebrio molitor (TmAtg6) and analyzed its functional role in the survival of the insect against infection. The expression of TmAtg6 was studied using qRT-PCR for the assessment of the transcript levels at various developmental stages in the different tissues. The results showed that TmAtg6 was highly expressed at the 6-day-old pupal stage. Tissue-specific expression studies revealed that TmAtg6 was highly expressed in the hemocytes of late larvae. The induction patterns of TmAtg6 in different tissues of T. molitor larvae were analyzed by injecting Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, or Candida albicans. The intracellular Gram-positive bacteria, L. monocytogenes, solely induced the expression of TmAtg6 in hemocytes at 9 h-post-injection, whilst in the fat body and gut, bimodal expression times were observed. RNAi-mediated knockdown of the TmAtg6 transcripts, followed by a challenge with microbes, showed a significant reduction in larval survival rate against L. monocytogenes. Taken together, our results suggest that TmAtg6 plays an essential role in anti-microbial defense against intracellular bacteria.
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Affiliation(s)
- Tariku Tesfaye Edosa
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Yong Hun Jo
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Maryam Keshavarz
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Ki Beom Park
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Jun Ho Cho
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Young Min Bae
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Bobae Kim
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
| | - Yong Seok Lee
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan City 31538, Korea;
| | - Yeon Soo Han
- Department of Applied Biology, Institute of Environmentally-Friendly Agriculture (IEFA), College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (T.T.E.); (Y.H.J.); (M.K.); (K.B.P.); (J.H.C.); (Y.M.B.); (B.K.)
- Correspondence: ; Tel.: +82-62-530-2072
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Zhao X, Huang P, Li G, Lv Z, Hu G, Xu Q. Activation of the leptin pathway by high expression of the long form of the leptin receptor (Ob-Rb) accelerates chondrocyte senescence in osteoarthritis. Bone Joint Res 2019; 8:425-436. [PMID: 31588359 PMCID: PMC6775539 DOI: 10.1302/2046-3758.89.bjr-2018-0325.r2] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Objectives Activation of the leptin pathway is closely correlated with human knee cartilage degeneration. However, the role of the long form of the leptin receptor (Ob-Rb) in cartilage degeneration needs further study. The aim of this study was to determine the effect of increasing the expression of Ob-Rb on chondrocytes using a lentiviral vector containing Ob-Rb. Methods The medial and lateral cartilage samples of the tibial plateau from 12 osteoarthritis (OA) patients were collected. Ob-Rb messenger RNA (mRNA) was detected in these samples. The Ob-Rb-overexpressing chondrocytes and controls were treated with different doses of leptin for two days. The activation of the p53/p21 pathway and the number of senescence-associated β-galactosidase (SA-β-gal)-positive cells were evaluated. The mammalian target of rapamycin (mTOR) signalling pathway and autophagy were detected after the chondrocytes were treated with a high dose of leptin. Results In total, 12 cases were found to have severe medial cartilage wear compared with the lateral cartilage. Immunofluorescence showed that the expression of Ob-Rb in the medial cartilage of the tibial plateau was high. High levels of leptin led to cell cycle arrest and inhibited autophagy. After overexpression of Ob-Rb, the physiological dose of leptin induced cell senescence in the chondrocytes. High doses of leptin inhibited autophagy by activating the mTOR signalling pathway. Blockade of the mTOR signalling pathway could restore autophagy and partially reverse senescence induced by leptin in chondrocytes. Conclusion In summary, the present study demonstrated that high doses of leptin induce cell senescence by activating the mTOR pathway in chondrocytes from OA cartilage. Highly expressed Ob-Rb accelerates chondrocyte senescence by activating the leptin pathway in OA. Cite this article: X. Zhao, P. Huang, G. Li, L. Zhendong, G. Hu, Q. Xu. Activation of the leptin pathway by high expression of the long form of the leptin receptor (Ob-Rb) accelerates chondrocyte senescence in osteoarthritis. Bone Joint Res 2019;8:425–436. DOI: 10.1302/2046-3758.89.BJR-2018-0325.R2.
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Affiliation(s)
- Xiang Zhao
- Department of Orthopaedics, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Huang
- Department of Orthopaedics, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Gen Li
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Zhendong Lv
- Department of Spine Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Guangyu Hu
- Department of Orthopaedics, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qingrong Xu
- Department of Orthopaedics, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Inhibition of miR-497 improves functional outcome after ischemic stroke by enhancing neuronal autophagy in young and aged rats. Neurochem Int 2019; 127:64-72. [DOI: 10.1016/j.neuint.2019.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/04/2019] [Accepted: 01/07/2019] [Indexed: 12/17/2022]
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Luo XY, Yuan JL, Liu J, Luo CN, Yang MH, Wei Q, Yang M, Chen Y, Liu Y, Yuan GH. Increased Macroautophagy in Interferon-Gamma-Producing T Cells from Patients with Newly Diagnosed Systemic Lupus Erythematosus. Chin Med J (Engl) 2018; 131:1527-1532. [PMID: 29941705 PMCID: PMC6032673 DOI: 10.4103/0366-6999.235110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Background Imbalance of interferon-gamma (IFN-γ), interleukin (IL)-4, and IL-17 producing by T cells is confirmed to contribute to the pathogenesis of systemic lupus erythematosus (SLE). Autophagy is now emerging as a core player in the development and the function of the immune system. Therefore, we investigated the autophagic behavior in IFN-γ-, IL-4-, and IL-17-producing T cells from patients with SLE. Methods Thirty patients with SLE and 25 healthy controls matched for gender and age were recruited between September 2016 and May 2017. The autophagic levels in IFN-γ+ T cells, IL-4+ T cells, and IL-17+ T cells from patients with newly diagnosed SLE and healthy controls were measured using flow cytometry. The plasma levels of IFN-γ were determined by enzyme-linked immunosorbent assay in SLE patients and healthy controls. Unpaired t-tests and the nonparametric Mann-Whitney U-test were used to compare data from patients with SLE and controls. Spearman's rank correlation coefficient was applied for calculation of the correlation between parallel variables in single samples. Results Our results showed increased percentage of autophagy in IFN-γ+ T cells from patients with SLE and healthy controls ([8.07 ± 2.72]% vs. [3.76 ± 1.67]%, t = 5.184, P < 0.001), but not in IL-4+ T cells or IL-17+ T cells (P > 0.05) as compared to healthy donors. Moreover, the plasma levels of IFN-γ in SLE patients were significantly higher than those in healthy controls ([68.9 ± 29.1] pg/ml vs. [24.7 ± 17.6] pg/ml, t = 5.430, P < 0.001). Moreover, in SLE patients, the percentage of autophagy in IFN-γ+ T cells was positively correlated with the plasma levels of IFN-γ (r = 0.344, P = 0.046), as well as the disease activity of patients with SLE (r = 0.379, P = 0.039). Conclusion The results indicate that autophagy in IFN-γ+ T cells from SLE patients is activated, which might contribute to the persistence of T cells producing IFN-γ, such as Th1 cells, and consequently result in the high plasma levels of IFN-γ, and then enhance the disease activity of SLE.
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Affiliation(s)
- Xiong-Yan Luo
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Jia-Li Yuan
- Department of Rheumatology, The First People's Hospital of Jian Yang City, Chengdu, Sichuan 641400, China
| | - Jing Liu
- Institute of Rheumatology and Immunology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 63700, China
| | - Cai-Nan Luo
- Department of Rheumatology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, Xinjiang 830000, China
| | - Ming-Hui Yang
- Institute of Rheumatology and Immunology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 63700, China
| | - Qin Wei
- Department of Rheumatology, The First People's Hospital of Xinxiang, Xinxiang Medical University, Xinxiang, Henan 453000, China
| | - Min Yang
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Yong Chen
- Department of Rheumatology, The First People's Hospital of Jian Yang City, Chengdu, Sichuan 641400, China
| | - Yi Liu
- Department of Rheumatology and Immunology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Guo-Hua Yuan
- Institute of Rheumatology and Immunology, Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan 63700, China
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Li J, Wang Q, Cai H, He Z, Wang H, Chen J, Zheng Z, Yin J, Liao Z, Xu H, Xiao J, Gong F. FGF1 improves functional recovery through inducing PRDX1 to regulate autophagy and anti-ROS after spinal cord injury. J Cell Mol Med 2018. [PMID: 29512938 PMCID: PMC5908106 DOI: 10.1111/jcmm.13566] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Fibroblast growth factor 1 (FGF1) is thought to exert protective and regenerative effects on neurons following spinal cord injury (SCI), although the mechanism of these effects is not well understood. The use of FGF1 as a therapeutic agent is limited by its lack of physicochemical stability and its limited capacity to cross the blood‐spinal cord barrier. Here, we demonstrated that overexpression of FGF1 in spinal cord following SCI significantly reduced tissue loss, protected neurons in the ventricornu, ameliorated pathological morphology of the lesion, dramatically improved tissue recovery via neuroprotection, and promoted axonal regeneration and remyelination both in vivo and in vivo. In addition, the autophagy and the expression levels of PRDX1 (an antioxidant protein) were induced by AAV‐FGF1 in PC12 cells after H2O2 treatment. Furthermore, the autophagy levels were not changed in PRDX1‐suppressing cells that were treated by AAV‐FGF1. Taken together, these results suggest that FGF1 improves functional recovery mainly through inducing PRDX1 expression to increase autophagy and anti‐ROS activity after SCI.
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Affiliation(s)
- Jiawei Li
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qingqing Wang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Hanxiao Cai
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zili He
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Haoli Wang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jian Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zengming Zheng
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiayu Yin
- School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhiyong Liao
- School of Life and Environmental Science, Wenzhou University, Wenzhou, Zhejiang, China
| | - Huazi Xu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jian Xiao
- School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Fanghua Gong
- School of Pharmacy, Wenzhou Medical University, Wenzhou, Zhejiang, China
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13
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Glover K, Li Y, Mukhopadhyay S, Leuthner Z, Chakravarthy S, Colbert CL, Sinha SC. Structural transitions in conserved, ordered Beclin 1 domains essential to regulating autophagy. J Biol Chem 2017; 292:16235-16248. [PMID: 28798234 DOI: 10.1074/jbc.m117.804195] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 07/20/2017] [Indexed: 01/10/2023] Open
Abstract
Beclin 1 (BECN1) is a key regulator of autophagy, a critical catabolic homeostasis pathway that involves sequestration of selected cytoplasmic components by multilayered vesicles called autophagosomes, followed by lysosomal fusion and degradation. BECN1 is a core component of class III phosphatidylinositol-3-kinase complexes responsible for autophagosome nucleation. Without heterologous binding partners, BECN1 forms an antiparallel homodimer via its coiled-coil domain (CCD). However, the last 16 CCD residues, composing an "overlap helix" (OH), have been crystallized in two mutually exclusive states: either as part of the CCD or packed against the C-terminal β-α repeated, autophagy-specific domain (BARAD). Here, using CD spectroscopy, isothermal titration calorimetry, and small-angle X-ray scattering, we show that in the homodimeric state, the OH transitions between these two different packing states, with the predominant state comprising the OH packed against the BARAD, contrary to expectations based on known BECN1 interactions with heterologous partners. We confirmed this observation by comparing the impact of mutating four residues that mediate packing of the OH against both the CCD and BARAD on structure and stability of the CCD, the OH+BARAD, and the two-domain CCD-BARAD. Last, we used cellular assays to demonstrate that mutation of these OH-interface residues abrogates starvation-induced up-regulation of autophagy but does not affect basal autophagy. In summary, we have identified a BECN1 helical region that transitions between packing as part of either one of two conserved domains (i.e. the CCD or the BARAD). Our findings have important implications for the relative stability of autophagy-inactive and autophagy-active BECN1 complexes.
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Affiliation(s)
- Karen Glover
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
| | - Yue Li
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
| | - Shreya Mukhopadhyay
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
| | - Zoe Leuthner
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
| | | | - Christopher L Colbert
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
| | - Sangita C Sinha
- From the Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota 58108-6050 and
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14
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Gut commensal Bacteroides acidifaciens prevents obesity and improves insulin sensitivity in mice. Mucosal Immunol 2017; 10:104-116. [PMID: 27118489 DOI: 10.1038/mi.2016.42] [Citation(s) in RCA: 322] [Impact Index Per Article: 40.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 02/04/2023]
Abstract
In humans, the composition of gut commensal bacteria is closely correlated with obesity. The bacteria modulate metabolites and influence host immunity. In this study, we attempted to determine whether there is a direct correlation between specific commensal bacteria and host metabolism. As mice aged, we found significantly reduced body weight and fat mass in Atg7ΔCD11c mice when compared with Atg7f/f mice. When mice shared commensal bacteria by co-housing or feces transfer experiments, body weight and fat mass were similar in both mouse groups. By pyrosequencing analysis, Bacteroides acidifaciens (BA) was significantly increased in feces of Atg7ΔCD11c mice compared with those of control Atg7f/f mice. Wild-type C57BL/6 (B6) mice fed with BA were significantly more likely to gain less weight and fat mass than mice fed with PBS. Of note, the expression level of peroxisome proliferator-activated receptor alpha (PPARα) was consistently increased in the adipose tissues of Atg7ΔCD11c mice, B6 mice transferred with fecal microbiota of Atg7ΔCD11c mice, and BA-fed B6 mice. Furthermore, B6 mice fed with BA showed elevated insulin levels in serum, accompanied by increased serum glucagon-like peptide-1 and decreased intestinal dipeptidyl peptidase-4. These finding suggest that BA may have potential for treatment of metabolic diseases such as diabetes and obesity.
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15
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Yu Y, Hou L, Song H, Xu P, Sun Y, Wu K. Akt/AMPK/mTOR pathway was involved in the autophagy induced by vitamin E succinate in human gastric cancer SGC-7901 cells. Mol Cell Biochem 2016; 424:173-183. [PMID: 27796683 DOI: 10.1007/s11010-016-2853-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 10/22/2016] [Indexed: 12/18/2022]
Abstract
Vitamin E succinate (VES), a derivative of vitamin E, is a promising cancer chemopreventive agent that inhibits tumor promotion by inducing apoptotic cell death. The effects of VES on autophagy, an intricate programmed process which helps cells survive in some stressed situations by degrading some cytoplasmic material, are unclear. When human gastric cancer cells SCG-7901 were exposed to VES, both the level of microtubule-associated protein 1 light chain 3 and the yeast ATG6 homolog Beclin-1 increased, and related autophagy genes were activated, thereby suggesting that autophagy was induced by VES. We also observed that VES-induced autophagy was accompanied by the activation of AMP-activated protein kinases (AMPK). VES-induced autophagy decreased when AMPK was inhibited by using small interfering RNA (siRNA), thereby suggesting that VES-induced autophagy is mediated by AMPK. Moreover, further studies revealed that the decreased activity of mammalian target of rapamycin (mTOR) and its downstream targets P70S6K and 4EBP-1 were involved in VES-activated autophagy associated with AMPK activation. The experiments also showed that the activity of protein kinases B (Akt)-mTOR axis was inhibited by VES. VES-induced AMPK activation could be attenuated by Akt activation. Overall, our studies demonstrated that AMPK was involved in the VES-induced autophagy. Crosstalk exists between AMPK and the Akt/mTOR axis. The results elucidated the mechanism of VES-induced autophagy in human gastric cancer cells.
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Affiliation(s)
- Yang Yu
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150086, China
| | - Liying Hou
- School of Public Health, North China University of Science and Technology, Tangshan, China
| | - Huacui Song
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150086, China
| | - Peixiang Xu
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150086, China
| | - Yue Sun
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150086, China
| | - Kun Wu
- Department of Nutrition and Food Hygiene, School of Public Health, Harbin Medical University, 157 Baojian Road, Harbin, 150086, China.
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16
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Mei Y, Glover K, Su M, Sinha SC. Conformational flexibility of BECN1: Essential to its key role in autophagy and beyond. Protein Sci 2016; 25:1767-85. [PMID: 27414988 DOI: 10.1002/pro.2984] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 07/09/2016] [Accepted: 07/12/2016] [Indexed: 01/16/2023]
Abstract
BECN1 (Beclin 1), a highly conserved eukaryotic protein, is a key regulator of autophagy, a cellular homeostasis pathway, and also participates in vacuolar protein sorting, endocytic trafficking, and apoptosis. BECN1 is important for embryonic development, the innate immune response, tumor suppression, and protection against neurodegenerative disorders, diabetes, and heart disease. BECN1 mediates autophagy as a core component of the class III phosphatidylinositol 3-kinase complexes. However, the exact mechanism by which it regulates the activity of these complexes, or mediates its other diverse functions is unclear. BECN1 interacts with several diverse protein partners, perhaps serving as a scaffold or interaction hub for autophagy. Based on extensive structural, biophysical and bioinformatics analyses, BECN1 consists of an intrinsically disordered region (IDR), which includes a BH3 homology domain (BH3D); a flexible helical domain (FHD); a coiled-coil domain (CCD); and a β-α-repeated autophagy-specific domain (BARAD). Each of these BECN1 domains mediates multiple diverse interactions that involve concomitant conformational changes. Thus, BECN1 conformational flexibility likely plays a key role in facilitating diverse protein interactions. Further, BECN1 conformation and interactions are also modulated by numerous post-translational modifications. A better structure-based understanding of the interplay between different BECN1 conformational and binding states, and the impact of post-translational modifications will be essential to elucidating the mechanism of its multiple biological roles.
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Affiliation(s)
- Yang Mei
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Karen Glover
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Minfei Su
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050
| | - Sangita C Sinha
- Department of Chemistry and Biochemistry, North Dakota State University, Fargo, North Dakota, 58108-6050.
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17
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Zhang X, Yin H, Li Z, Zhang T, Yang Z. Nano-TiO 2 induces autophagy to protect against cell death through antioxidative mechanism in podocytes. Cell Biol Toxicol 2016; 32:513-527. [PMID: 27430495 DOI: 10.1007/s10565-016-9352-y] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 07/05/2016] [Indexed: 12/20/2022]
Abstract
Autophagy is a cellular pathway involved in degradation of damaged organelles and proteins in order to keep cellular homeostasis. It plays vital role in podocytes. Titanium dioxide nanoparticles (nano-TiO2) are known to induce autophagy in cells, but little has been reported about the mechanism of this process in podocytes and the role of autophagy in podocyte death. In the present study, we examined how nano-TiO2 induced authophagy. Besides that, whether autophagy could protect podocytes from the damage induced by nano-TiO2 and its mechanism was also investigated. Western blot assay and acridine orange staining presented that nano-TiO2 significantly enhanced autophagy flux in podocytes. In addition, AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) were involved in such process. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay indicated that upregulated level of autophagy induced by rapamycin in high concentration nano-TiO2-treated podocytes could significantly reduce the level of oxidative stress and alleviate podocyte death. Downregulating the level of autophagy with 3-methyladenine had the opposite effects. These findings indicate that nano-TiO2 induces autophagy through activating AMPK to inhibit mTOR in podocytes, and such autophagy plays a protecting role against oxidative stress on the cell proliferation. Changing autophagy level may become a new treatment strategy to relieve the damage induced by nano-TiO2 in podocytes.
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Affiliation(s)
- Xiaochen Zhang
- College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Hongqiang Yin
- College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Zhigui Li
- College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, 300071, China
| | - Tao Zhang
- College of Life Sciences, Nankai University, Tianjin, 300071, China
| | - Zhuo Yang
- College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials Ministry of Education, Nankai University, Tianjin, 300071, China.
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Di Fruscio G, Schulz A, De Cegli R, Savarese M, Mutarelli M, Parenti G, Banfi S, Braulke T, Nigro V, Ballabio A. Lysoplex: An efficient toolkit to detect DNA sequence variations in the autophagy-lysosomal pathway. Autophagy 2016; 11:928-38. [PMID: 26075876 PMCID: PMC4502703 DOI: 10.1080/15548627.2015.1043077] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The autophagy-lysosomal pathway (ALP) regulates cell homeostasis and plays a crucial role in human diseases, such as lysosomal storage disorders (LSDs) and common neurodegenerative diseases. Therefore, the identification of DNA sequence variations in genes involved in this pathway and their association with human diseases would have a significant impact on health. To this aim, we developed Lysoplex, a targeted next-generation sequencing (NGS) approach, which allowed us to obtain a uniform and accurate coding sequence coverage of a comprehensive set of 891 genes involved in lysosomal, endocytic, and autophagic pathways. Lysoplex was successfully validated on 14 different types of LSDs and then used to analyze 48 mutation-unknown patients with a clinical phenotype of neuronal ceroid lipofuscinosis (NCL), a genetically heterogeneous subtype of LSD. Lysoplex allowed us to identify pathogenic mutations in 67% of patients, most of whom had been unsuccessfully analyzed by several sequencing approaches. In addition, in 3 patients, we found potential disease-causing variants in novel NCL candidate genes. We then compared the variant detection power of Lysoplex with data derived from public whole exome sequencing (WES) efforts. On average, a 50% higher number of validated amino acid changes and truncating variations per gene were identified. Overall, we identified 61 truncating sequence variations and 488 missense variations with a high probability to cause loss of function in a total of 316 genes. Interestingly, some loss-of-function variations of genes involved in the ALP pathway were found in homozygosity in the normal population, suggesting that their role is not essential. Thus, Lysoplex provided a comprehensive catalog of sequence variants in ALP genes and allows the assessment of their relevance in cell biology as well as their contribution to human disease.
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The mammalian target of rapamycin at the crossroad between cognitive aging and Alzheimer's disease. NPJ Aging Mech Dis 2015; 1:15008. [PMID: 28721257 PMCID: PMC5514987 DOI: 10.1038/npjamd.2015.8] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/10/2015] [Accepted: 09/01/2015] [Indexed: 12/12/2022] Open
Abstract
Age-dependent cognitive decline is a major debilitating event affecting even individuals who are otherwise healthy. Understanding the molecular basis underlying these changes may increase the healthspan of the elderly population. It may also reveal insights into the pathogenesis of numerous neurodegenerative disorders characterized by cognitive deficits, as aging is the major risk factor for most of these disorders. Alzheimer’s disease (AD), the most common neurodegenerative disorder, first manifests itself as deficits in encoding new memories. As AD progresses, these deficits spread to other cognitive domains that further debilitate the person before contributing to their demise. Suppression of the mammalian target of rapamycin (mTOR) increases healthspan and lifespan in several organisms. Numerous reports have linked alterations in mTOR signaling to age-dependent cognitive decline and the pathogenesis of AD. This review will discuss recent work highlighting the complex role of mTOR in cognitive aging and in the pathogenesis of AD.
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Zhang Y, Vasheghani F, Li YH, Blati M, Simeone K, Fahmi H, Lussier B, Roughley P, Lagares D, Pelletier JP, Martel-Pelletier J, Kapoor M. Cartilage-specific deletion of mTOR upregulates autophagy and protects mice from osteoarthritis. Ann Rheum Dis 2015; 74:1432-40. [PMID: 24651621 DOI: 10.1136/annrheumdis-2013-204599] [Citation(s) in RCA: 319] [Impact Index Per Article: 31.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 02/16/2014] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Mammalian target of rapamycin (mTOR) (a serine/threonine protein kinase) is a major repressor of autophagy, a cell survival mechanism. The specific in vivo mechanism of mTOR signalling in OA pathophysiology is not fully characterised. We determined the expression of mTOR and known autophagy genes in human OA cartilage as well as mouse and dog models of experimental OA. We created cartilage-specific mTOR knockout (KO) mice to determine the specific role of mTOR in OA pathophysiology and autophagy signalling in vivo. METHODS Inducible cartilage-specific mTOR KO mice were generated and subjected to mouse model of OA. Human OA chondrocytes were treated with rapamycin and transfected with Unc-51-like kinase 1 (ULK1) siRNA to determine mTOR signalling. RESULTS mTOR is overexpressed in human OA cartilage as well as mouse and dog experimental OA. Upregulation of mTOR expression co-relates with increased chondrocyte apoptosis and reduced expression of key autophagy genes during OA. Subsequently, we show for the first time that cartilage-specific ablation of mTOR results in increased autophagy signalling and a significant protection from destabilisation of medial meniscus (DMM)-induced OA associated with a significant reduction in the articular cartilage degradation, apoptosis and synovial fibrosis. Furthermore, we show that regulation of ULK1/adenosine monophosphate-activated protein kinase (AMPK) signalling pathway by mTOR may in part be responsible for regulating autophagy signalling and the balance between catabolic and anabolic factors in the articular cartilage. CONCLUSIONS This study provides a direct evidence of the role of mTOR and its downstream modulation of autophagy in articular cartilage homeostasis.
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Affiliation(s)
- Yue Zhang
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Faezeh Vasheghani
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Ying-Hua Li
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Meryem Blati
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Kayla Simeone
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Hassan Fahmi
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Bertrand Lussier
- Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Montreal, Montreal, Quebec, Canada
| | - Peter Roughley
- Genetics Unit, Shriners Hospital, McGill University, Montreal, Quebec, Canada
| | - David Lagares
- Pulmonary and Critical Care Unit and Center for Immunology and Inflammatory Diseases, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Massachusetts, USA
| | - Jean-Pierre Pelletier
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Johanne Martel-Pelletier
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada
| | - Mohit Kapoor
- Osteoarthritis Research Unit, University of Montreal Research Centre (CRCHUM), Montreal, Quebec, Canada Division of Genetics and Development, The Toronto Western Research Institute, Toronto Western Hospital, The University Health Network (UHN), Toronto, Ontario, Canada
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Matsuzaki T, Matsushita T, Tabata Y, Saito T, Matsumoto T, Nagai K, Kuroda R, Kurosaka M. Intra-articular administration of gelatin hydrogels incorporating rapamycin–micelles reduces the development of experimental osteoarthritis in a murine model. Biomaterials 2014; 35:9904-9911. [DOI: 10.1016/j.biomaterials.2014.08.041] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 08/05/2014] [Indexed: 12/19/2022]
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22
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Fu MY, He YJ, Lv X, Liu ZH, Shen Y, Ye GR, Deng YM, Shu JC. Transforming growth factor‑β1 reduces apoptosis via autophagy activation in hepatic stellate cells. Mol Med Rep 2014; 10:1282-8. [PMID: 25059289 PMCID: PMC4121427 DOI: 10.3892/mmr.2014.2383] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 06/02/2014] [Indexed: 02/07/2023] Open
Abstract
Autophagy is a metabolic process that is important in fibrogenesis, in which cellular components are degraded by lysosomal machinery. Transforming growth factor β1 (TGF‑β1) is a potent fibrogenic cytokine involved in liver fibrosis; however, it remains elusive whether autophagy is regulated by TGF‑β1 in this process. In the present study, the function of TGF‑β1‑mediated autophagy in the proliferation and apoptosis of hepatic stellate cells (HSCs) was investigated. A rat HSC cell line (HSC‑T6) was incubated with or without TGF‑β1 followed by bafilomycin A1, and microtubule-associated proteins 1A/1B light chain 3 (LC3) small interfering (si)RNA was used to inhibit autophagy in order to assess the association between TGF‑β1 and autophagy. HSC‑T6 cell transient transfection was accomplished with a pLVX‑AcGFP‑N1‑rLC3B‑encoding plasmid. An MTS assay and flow cytometry were utilized to detect proliferation and apoptosis of HSC‑T6 cells. Quantitative polymerase chain reaction, immunofluorescence and western blot analysis were used to detect the presence of activation markers. Proliferation was increased and apoptosis was reduced in HSC‑T6 cells treated with TGF‑β1 compared with cells subjected to serum deprivation. However, when HSC‑T6 cells were treated with bafilomycin A1 and LC3 siRNA, increased apoptosis and reduced proliferation were observed. In addition, protein and mRNA expression levels of the autophagy marker LC3 were significantly increased. GFP‑LC3 punctate markings were more prolific following TGF‑β1 treatment of HSC‑T6 cells, indicating that TGF‑β1 may rescue HSC‑T6 cells from serum deprivation and reduce apoptosis via autophagy induction. The present study elucidated the possible functions of TGF‑β1‑mediated autophagy in the pathological process of liver fibrosis.
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Affiliation(s)
- Mei-Ya Fu
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Ya-Jun He
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Xia Lv
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Zhi-He Liu
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Yan Shen
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Guo-Rong Ye
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Yan-Mei Deng
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
| | - Jian-Chang Shu
- Department of Gastroenterology, The Fourth Affiliated Hospital of the Medical College of Jinan University, Guangzhou Red Cross Hospital, Guangzhou, Guangdong 510220, P.R. China
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Watanabe R, Fujii H, Shirai T, Saito S, Ishii T, Harigae H. Autophagy plays a protective role as an anti-oxidant system in human T cells and represents a novel strategy for induction of T-cell apoptosis. Eur J Immunol 2014; 44:2508-20. [DOI: 10.1002/eji.201344248] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 03/24/2014] [Accepted: 04/30/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Ryu Watanabe
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Hiroshi Fujii
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Tsuyoshi Shirai
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Shinichiro Saito
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Tomonori Ishii
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
| | - Hideo Harigae
- Department of Hematology and Rheumatology; Tohoku University Graduate School of Medicine; Sendai Japan
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Bang S, Shin H, Song H, Suh CS, Lim HJ. Autophagic activation in vitrified-warmed mouse oocytes. Reproduction 2014; 148:11-9. [PMID: 24760879 DOI: 10.1530/rep-14-0036] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Vitrification involves the use of cryoprotectants (CPAs) and liquid nitrogen (LN2), which may cause osmotic damage and cryoinjury to oocytes. Autophagy is widely recognized as a survival or response mechanism elicited by various environmental and cellular stressors. However, the induction of autophagy in vitrified-warmed oocytes has not been examined. In this work, we investigated whether the vitrification-warming process induces autophagy in mouse oocytes. Metaphase II (MII) oocytes that were vitrified and stored in LN2 for at least 2 weeks were used in the study. In RT-PCR analyses, we observed that several Atg genes such as Atg5, Atg7, Atg12, LC3a (Map1lc3a), LC3b (Map1lc3b), and Beclin1 were expressed in MII mouse oocytes. Slight reduction in mRNA levels of Atg7 and Atg12 in vitrified-warmed oocytes was noted, and expression of these genes was not significantly influenced. Confocal live imaging analysis using oocytes from GFP-LC3 transgenic mice revealed that vitrified-warmed oocytes had a significantly higher number of GFP-LC3 puncta in comparison to fresh oocytes. The expression of BECLIN1 protein was also increased in vitrified-warmed oocytes. Treatment with 3-methyladenine, an inhibitor of autophagy, did not significantly affect the rates of oocyte survival, IVF, and embryonic development after warming and IVF. The results suggest that the observed autophagic activation in vitrified-warmed oocytes is a natural adaptive response to cold stress. Collectively, we show for the first time that vitrified-warmed mouse oocytes exhibit autophagic activation during warming and that this response is not induced by CPA-containing solutions. The induction of autophagy by cold temperature is first reported herein.
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Affiliation(s)
- Soyoung Bang
- Department of Biomedical Science and TechnologyInstitute of Biomedical Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, KoreaDepartment of Biomedical ScienceCollege of Life Science, CHA University, Seoul 135-913, KoreaDepartment of Obstetrics and GynecologySeoul National University Bundang Hospital, Seongnam, Gyeonggi-do 463-707, Korea
| | - Hyejin Shin
- Department of Biomedical Science and TechnologyInstitute of Biomedical Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, KoreaDepartment of Biomedical ScienceCollege of Life Science, CHA University, Seoul 135-913, KoreaDepartment of Obstetrics and GynecologySeoul National University Bundang Hospital, Seongnam, Gyeonggi-do 463-707, Korea
| | - Haengseok Song
- Department of Biomedical Science and TechnologyInstitute of Biomedical Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, KoreaDepartment of Biomedical ScienceCollege of Life Science, CHA University, Seoul 135-913, KoreaDepartment of Obstetrics and GynecologySeoul National University Bundang Hospital, Seongnam, Gyeonggi-do 463-707, Korea
| | - Chang Suk Suh
- Department of Biomedical Science and TechnologyInstitute of Biomedical Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, KoreaDepartment of Biomedical ScienceCollege of Life Science, CHA University, Seoul 135-913, KoreaDepartment of Obstetrics and GynecologySeoul National University Bundang Hospital, Seongnam, Gyeonggi-do 463-707, Korea
| | - Hyunjung Jade Lim
- Department of Biomedical Science and TechnologyInstitute of Biomedical Science and Technology, Konkuk University, 120 Neungdong-ro, Gwangjin-gu, Seoul 143-701, KoreaDepartment of Biomedical ScienceCollege of Life Science, CHA University, Seoul 135-913, KoreaDepartment of Obstetrics and GynecologySeoul National University Bundang Hospital, Seongnam, Gyeonggi-do 463-707, Korea
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Vibrio effector protein, VopQ, forms a lysosomal gated channel that disrupts host ion homeostasis and autophagic flux. Proc Natl Acad Sci U S A 2013; 110:11559-64. [PMID: 23798441 DOI: 10.1073/pnas.1307032110] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Defects in normal autophagic pathways are implicated in numerous human diseases--such as neurodegenerative diseases, cancer, and cardiomyopathy--highlighting the importance of autophagy and its proper regulation. Herein we show that Vibrio parahaemolyticus uses the type III effector VopQ (Vibrio outer protein Q) to alter autophagic flux by manipulating the partitioning of small molecules and ions in the lysosome. This effector binds to the conserved Vo domain of the vacuolar-type H(+)-ATPase and causes deacidification of the lysosomes within minutes of entering the host cell. VopQ forms a gated channel ∼18 Å in diameter that facilitates outward flux of ions across lipid bilayers. The electrostatic interactions of this type 3 secretion system effector with target membranes dictate its preference for host vacuolar-type H(+)-ATPase-containing membranes, indicating that its pore-forming activity is specific and not promiscuous. As seen with other effectors, VopQ is exploiting a eukaryotic mechanism, in this case manipulating lysosomal homeostasis and autophagic flux through transmembrane permeation.
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Wafa K, MacLean J, Zhang F, Pasumarthi KBS. Characterization of growth suppressive functions of a splice variant of cyclin D2. PLoS One 2013; 8:e53503. [PMID: 23326442 PMCID: PMC3542336 DOI: 10.1371/journal.pone.0053503] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Accepted: 11/30/2012] [Indexed: 12/19/2022] Open
Abstract
We have recently cloned a novel splice variant of cyclin D2 termed as cycD2SV. CycD2SV overexpression in several immortalized cell lines led to formation of ubiquitinated protein aggregates accompanied by a significant decrease in cell proliferation. Based on immuno co-localization and ultrastructural analysis experiments, cycD2SV protein aggregates were frequently found in various subcellular compartments such as endosomes, autophagosomes, lysosomes and the microtubule organizing centre. Secondary structure analysis revealed that the amino terminal α-helix in cycD2SV is not tightly packed with the cyclin box suggesting a misfolded conformation compared to other cyclins. Deletion analysis suggests that 1–53 amino acid region of cycD2SV may be required for protein aggregation and 54–136 amino acid region may mediate cell cycle inhibition. Based on co-immunoprecipitation experiments, we have shown that cycD2SV binds to cycD2 as well as CDK4. In addition, gene expression analysis demonstrated an upregulation in GADD45α and dynamin 2 mRNA levels in cycD2SV overexpressing cells. These two proteins are known to play critical roles in the DNA damage response and apoptosis pathways. TUNEL experiments were negative for apoptosis, however, cycD2SV expressing cells were more sensitive to cell death induced by external stressors such as trypsinization. Collectively our results suggest that cycD2SV mediates cell cycle inhibition by sequestering endogenous cell cycle proteins, such as cycD2 and CDK4, and possibly targeting them for ubiquitin mediated protein degradation.
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Affiliation(s)
- Karim Wafa
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jessica MacLean
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Feixiong Zhang
- Department of Pharmacology, Dalhousie University, Halifax, Nova Scotia, Canada
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Sano R, Hou YCC, Hedvat M, Correa RG, Shu CW, Krajewska M, Diaz PW, Tamble CM, Quarato G, Gottlieb RA, Yamaguchi M, Nizet V, Dahl R, Thomas DD, Tait SW, Green DR, Fisher PB, Matsuzawa SI, Reed JC. Endoplasmic reticulum protein BI-1 regulates Ca²⁺-mediated bioenergetics to promote autophagy. Genes Dev 2012; 26:1041-54. [PMID: 22588718 DOI: 10.1101/gad.184325.111] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Autophagy is a lysosomal degradation pathway that converts macromolecules into substrates for energy production during nutrient-scarce conditions such as those encountered in tumor microenvironments. Constitutive mitochondrial uptake of endoplasmic reticulum (ER) Ca²⁺ mediated by inositol triphosphate receptors (IP₃Rs) maintains cellular bioenergetics, thus suppressing autophagy. We show that the ER membrane protein Bax inhibitor-1 (BI-1) promotes autophagy in an IP₃R-dependent manner. By reducing steady-state levels of ER Ca²⁺ via IP₃Rs, BI-1 influences mitochondrial bioenergetics, reducing oxygen consumption, impacting cellular ATP levels, and stimulating autophagy. Furthermore, BI-1-deficient mice show reduced basal autophagy, and experimentally reducing BI-1 expression impairs tumor xenograft growth in vivo. BI-1's ability to promote autophagy could be dissociated from its known function as a modulator of IRE1 signaling in the context of ER stress. The results reveal BI-1 as a novel autophagy regulator that bridges Ca²⁺ signaling between ER and mitochondria, reducing cellular oxygen consumption and contributing to cellular resilience in the face of metabolic stress.
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Affiliation(s)
- Renata Sano
- Sanford-Burnham Medical Research Institute, La Jolla, California 92037, USA
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Effect of air exposure on lysosomal tissues of Mytilus edulis L. from natural intertidal wild beds and submerged culture ropes. Comp Biochem Physiol A Mol Integr Physiol 2012; 161:327-36. [DOI: 10.1016/j.cbpa.2011.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 12/01/2011] [Accepted: 12/01/2011] [Indexed: 11/20/2022]
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29
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Zhang Y, Calderwood SK. Autophagy, protein aggregation and hyperthermia: a mini-review. Int J Hyperthermia 2011; 27:409-14. [PMID: 21756038 DOI: 10.3109/02656736.2011.552087] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
PURPOSE We aim to explore the role of macroautophagy in cellular responses to hyperthermia. Protein damage incurred during hyperthermia can either lead to cell death or may be repaired by polypeptide quality control pathways including: (1) the deterrence of protein unfolding by molecular chaperones and (2) proteolysis of the denatured proteins within the proteasome. A third pathway of protein quality control is triggered by formation of protein aggregates in the heat shocked cell. This is the macroautophagy pathway in which protein aggregates are transported to specialised organelles called autolysosomes capable of degrading the aggregates. The consequences for cell viability of triggering this pathway are complex and may involve cell death, although under many circumstances, including exposure of cells to hyperthermia, autophagy leads to enhanced cell survival. We have discussed mechanisms by which cells detect protein aggregates and recruit them into the macroautophagy pathway as well as the potential role of inhibiting this process in hyperthermia. CONCLUSIONS Directed macroautophagy, with its key role in protein quality control, seems an attractive target for a therapy such as hyperthermia that functions principally through denaturing the proteome. However, much work is needed to decode the mechanisms of thermal stress-mediated macroautophagy and their role in survival/death of cancer cells before recommendations can be made on targeting this pathway in combination with hyperthermia.
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Affiliation(s)
- Yue Zhang
- Molecular and Cellular Radiation Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School , 99 Brookline Avenue, Boston, MA 02215 , USA
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