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Zhang GY, Wang J, Jia YJ, Han R, Li P, Zhu DN. MicroRNA-9 promotes the neuronal differentiation of rat bone marrow mesenchymal stem cells by activating autophagy. Neural Regen Res 2015; 10:314-20. [PMID: 25883633 PMCID: PMC4392682 DOI: 10.4103/1673-5374.143439] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2014] [Indexed: 12/31/2022] Open
Abstract
MicroRNA-9 (miR-9) has been shown to promote the differentiation of bone marrow mesenchymal stem cells into neuronal cells, but the precise mechanism is unclear. Our previous study confirmed that increased autophagic activity improved the efficiency of neuronal differentiation in bone marrow mesenchymal stem cells. Accumulating evidence reveals that miRNAs adjust the autophagic pathways. This study used miR-9-1 lentiviral vector and miR-9-1 inhibitor to modulate the expression level of miR-9. Autophagic activity and neuronal differentiation were measured by the number of light chain-3 (LC3)-positive dots, the ratio of LC3-II/LC3, and the expression levels of the neuronal markers enolase and microtubule-associated protein 2. Results showed that LC3-positive dots, the ratio of LC3-II/LC3, and expression of neuron specific enolase and microtubule-associated protein 2 increased in the miR-9+ group. The above results suggest that autophagic activity increased and bone marrow mesenchymal stem cells were prone to differentiate into neuronal cells when miR-9 was overexpressed, demonstrating that miR-9 can promote neuronal differentiation by increasing autophagic activity.
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Affiliation(s)
- Guang-Yu Zhang
- Rehabilitation and Treatment Center for Children with Cerebral Palsy of Henan Province, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Jun Wang
- Rehabilitation and Treatment Center for Children with Cerebral Palsy of Henan Province, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Yan-Jie Jia
- Department of Neurology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Rui Han
- Department of Pediatrics, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Ping Li
- Rehabilitation and Treatment Center for Children with Cerebral Palsy of Henan Province, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Deng-Na Zhu
- Rehabilitation and Treatment Center for Children with Cerebral Palsy of Henan Province, the Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
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Sun KT, Chen MYC, Tu MG, Wang IK, Chang SS, Li CY. MicroRNA-20a regulates autophagy related protein-ATG16L1 in hypoxia-induced osteoclast differentiation. Bone 2015; 73:145-53. [PMID: 25485521 DOI: 10.1016/j.bone.2014.11.026] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 11/25/2014] [Accepted: 11/29/2014] [Indexed: 12/13/2022]
Abstract
Autophagy and autophagy-related proteins (ATGs) play decisive roles in osteoclast differentiation. Emerging lines of evidence show the deregulation of miRNA in autophagic responses. However, the role of hypoxia and involvement of miRNA in osteoclast differentiation are unclear. In the present study, we demonstrate that hypoxia caused induction of autophagy and osteoclast differentiation markers in RAW264.7 cells stimulated with M-CSF and RANKL. In addition, miR-20a was significantly repressed during hypoxia and identified as the prime candidate involved in hypoxia-induced osteoclast differentiation. The results from dual luciferase reporter assay revealed that miR-20a directly targets Atg16l1 by binding to its 3'UTR end. Further, miR-20a transfection studies showed significant down regulation of autophagic proteins (LC3-II and ATG16L1) and osteoclast differentiation markers (Nfatc1, Traf6, and Trap) thus confirming the functional role of miR-20a under hypoxic conditions. Results of chromatin immunoprecipitation assay showed that HIF-1α binds to miRNA-20a. From miRNA Q-PCR results, we confirmed that shRNA HIF-1α knockdown significantly downregulated both autophagy (LC3, p62, Atg5, Atg12, Atg16l1, Atg7, Becn1, Atg9a) and osteoclast markers (Traf6, Nfatc1, Ctsk, cFos, Mmp9, Trap) in RAW264.7 cells. Thus, our findings suggest that the regulatory axis of HIF-1α-miRNA-20a-Atg16l1 might be a critical mechanism for hypoxia-induced osteoclast differentiation.
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Affiliation(s)
- Kuo-Ting Sun
- Graduate Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Department of Pediatric Dentistry, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan; School of Dentistry, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan
| | - Michael Y C Chen
- School of Dentistry, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Department of Oral & Maxillofacial Surgeon, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan
| | - Ming-Gene Tu
- School of Dentistry, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan
| | - I-Kuan Wang
- Graduate Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Division of Nephrology, Department of medicine, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan
| | - Shih-Sheng Chang
- Graduate Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Division of Cardiology, Department of medicine, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan
| | - Chi-Yuan Li
- Graduate Institute of Clinical Medical Science, China Medical University, No. 91 Hsueh-Shih Rd., Taichung, Taiwan; Department of Anesthesiology, China Medical University Hospital, No. 2 Yu-Der Rd., Taichung, Taiwan.
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103
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Lu N, Wang B, Deng X, Zhao H, Wang Y, Li D. Autophagy occurs within an hour of adenosine triphosphate treatment after nerve cell damage: the neuroprotective effects of adenosine triphosphate against apoptosis. Neural Regen Res 2014; 9:1599-605. [PMID: 25368646 PMCID: PMC4211201 DOI: 10.4103/1673-5374.141811] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2014] [Indexed: 12/26/2022] Open
Abstract
After hypoxia, ischemia, or inflammatory injuries to the central nervous system, the damaged cells release a large amount of adenosine triphosphate, which may cause secondary neuronal death. Autophagy is a form of cell death that also has neuroprotective effects. Cell Counting Kit assay, monodansylcadaverine staining, flow cytometry, western blotting, and real-time PCR were used to determine the effects of exogenous adenosine triphosphate treatment at different concentrations (2, 4, 6, 8, 10 mmol/L) over time (1, 2, 3, and 6 hours) on the apoptosis and autophagy of SH-SY5Y cells. High concentrations of extracellular adenosine triphosphate induced autophagy and apoptosis of SH-SY5Y cells. The enhanced autophagy first appeared, and peaked at 1 hour after treatment with adenosine triphosphate. Cell apoptosis peaked at 3 hours, and persisted through 6 hours. With prolonged exposure to the adenosine triphosphate treatment, the fraction of apoptotic cells increased. These data suggest that the SH-SY5Y neural cells initiated autophagy against apoptosis within an hour of adenosine triphosphate treatment to protect themselves against injury.
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Affiliation(s)
- Na Lu
- Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Baoying Wang
- Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Xiaohui Deng
- Department of Human Anatomy, Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Honggang Zhao
- Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Yong Wang
- Department of Laboratory Animal Center, Xinxiang Medical University, Xinxiang, Henan Province, China
| | - Dongliang Li
- Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang, Henan Province, China
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104
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Li RF, Chen G, Ren JG, Zhang W, Wu ZX, Liu B, Zhao Y, Zhao YF. The adaptor protein p62 is involved in RANKL-induced autophagy and osteoclastogenesis. J Histochem Cytochem 2014; 62:879-88. [PMID: 25163928 DOI: 10.1369/0022155414551367] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Previous studies have implicated autophagy in osteoclast differentiation. The aim of this study was to investigate the potential role of p62, a characterized adaptor protein for autophagy, in RANKL-induced osteoclastogenesis. Real-time quantitative PCR and western blot analyses were used to evaluate the expression levels of autophagy-related markers during RANKL-induced osteoclastogenesis in mouse macrophage-like RAW264.7 cells. Meanwhile, the potential relationship between p62/LC3 localization and F-actin ring formation was tested using double-labeling immunofluorescence. Then, the expression of p62 in RAW264.7 cells was knocked down using small-interfering RNA (siRNA), followed by detecting its influence on RANKL-induced autophagy activation, osteoclast differentiation, and F-actin ring formation. The data showed that several key autophagy-related markers including p62 were significantly altered during RANKL-induced osteoclast differentiation. In addition, the expression and localization of p62 showed negative correlation with LC3 accumulation and F-actin ring formation, as demonstrated by western blot and immunofluorescence analyses, respectively. Importantly, the knockdown of p62 obviously attenuated RANKL-induced expression of autophagy- and osteoclastogenesis-related genes, formation of TRAP-positive multinuclear cells, accumulation of LC3, as well as formation of F-actin ring. Our study indicates that p62 may play essential roles in RANKL-induced autophagy and osteoclastogenesis, which may help to develop a novel therapeutic strategy against osteoclastogenesis-related diseases.
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Affiliation(s)
- Rui-Fang Li
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Gang Chen
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Jian-Gang Ren
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Wei Zhang
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Zhong-Xing Wu
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Bing Liu
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Yi Zhao
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
| | - Yi-Fang Zhao
- State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology (RFL, GC, JGR, WZ, ZXW, BL, YZ, YFZ) Wuhan University, Wuhan, ChinaDepartment of Oral and Maxillofacial Surgery, School & Hospital of Stomatology (GC, ZXW, BL, YFZ) Wuhan University, Wuhan, ChinaDepartment of Prosthodontics, School & Hospital of Stomatology (YZ) Wuhan University, Wuhan, China
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105
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Kalamida D, Karagounis IV, Giatromanolaki A, Koukourakis MI. Important role of autophagy in endothelial cell response to ionizing radiation. PLoS One 2014; 9:e102408. [PMID: 25010689 PMCID: PMC4092133 DOI: 10.1371/journal.pone.0102408] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 06/18/2014] [Indexed: 01/12/2023] Open
Abstract
Objectives Vasculature damage is an important contributor to the side-effects of radiotherapy. The aim of this study is to provide insights into the radiobiology of the autophagic response of endothelial cells. Methods and Materials Human umbilical vascular endothelial cells (HUVEC) were exposed to 2 Gy of ionizing radiation (IR) and studied using confocal microscopy and western blot analysis, at 4 and 8 days post-irradiation. The role of autophagy flux in HUVEC radio-sensitivity was also examined. Results IR-induced accumulation of LC3A+, LC3B+ and p62 cytoplasmic vacuoles, while in double immunostaining with lysosomal markers (LAMP2a and CathepsinD) repression of the autophagolysosomal flux was evident. Autophagy-related proteins (ATF4, HIF1α., HIF2α, Beclin1) were, however, induced excluding an eventual repressive effect of radiation on autophagy initiating protein expression. Exposure of HUVEC to SMER28, an mTOR-independent inducer of autophagy, enhanced proLC3 and LC3A, B-I protein expression and accelerated the autophagic flux. Pre-treatment of HUVEC with SMER28 protected against the blockage of autophagic flux induced by IR and conferred radio-resistance. Suppression of LC3A/LC3B proteins with siRNAs resulted in radio-sensitization. Conclusions The current data provide a rationale for the development of novel radioprotection policies targeting the autophagic pathway.
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Affiliation(s)
- Dimitra Kalamida
- Department of Radiotherapy/Oncology, Democritus University of Thrace, and University General Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Ilias V. Karagounis
- Department of Radiotherapy/Oncology, Democritus University of Thrace, and University General Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Alexandra Giatromanolaki
- Department of Pathology, Democritus University of Thrace, and University General Hospital of Alexandroupolis, Alexandroupolis, Greece
| | - Michael I. Koukourakis
- Department of Radiotherapy/Oncology, Democritus University of Thrace, and University General Hospital of Alexandroupolis, Alexandroupolis, Greece
- * E-mail:
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106
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Basu S, Rajakaruna S, Reyes B, Van Bockstaele E, Menko AS. Suppression of MAPK/JNK-MTORC1 signaling leads to premature loss of organelles and nuclei by autophagy during terminal differentiation of lens fiber cells. Autophagy 2014; 10:1193-211. [PMID: 24813396 PMCID: PMC4203547 DOI: 10.4161/auto.28768] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Although autophagic pathways are essential to developmental processes, many questions still remain regarding the initiation signals that regulate autophagy in the context of differentiation. To address these questions we studied the ocular lens, as the programmed elimination of nuclei and organelles occurs in a precisely regulated spatiotemporal manner to form the organelle-free zone (OFZ), a characteristic essential for vision acuity. Here, we report our discovery that inactivation of MAPK/JNK induces autophagy for formation of the OFZ through its regulation of MTORC1, where MAPK/JNK signaling is required for both MTOR activation and RPTOR/RAPTOR phosphorylation. Autophagy pathway proteins including ULK1, BECN1/Beclin 1, and MAP1LC3B2/LC3B-II were upregulated in the presence of inhibitors to either MAPK/JNK or MTOR, inducing autophagic loss of organelles to form the OFZ. These results reveal that MAPK/JNK is a positive regulator of MTORC1 signaling and its developmentally regulated inactivation provides an inducing signal for the coordinated autophagic removal of nuclei and organelles required for lens function.
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Affiliation(s)
- Subhasree Basu
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
| | - Suren Rajakaruna
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
| | - Beverly Reyes
- Department of Neuroscience; Farber Institute for Neuroscience; Thomas Jefferson University; Philadelphia, PA USA
| | - Elisabeth Van Bockstaele
- Department of Neuroscience; Farber Institute for Neuroscience; Thomas Jefferson University; Philadelphia, PA USA
| | - A Sue Menko
- Department of Pathology, Anatomy and Cell Biology; Thomas Jefferson University; Philadelphia, PA USA
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107
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Sambandam Y, Townsend MT, Pierce JJ, Lipman CM, Haque A, Bateman TA, Reddy SV. Microgravity control of autophagy modulates osteoclastogenesis. Bone 2014; 61:125-31. [PMID: 24463210 PMCID: PMC4384509 DOI: 10.1016/j.bone.2014.01.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 12/11/2013] [Accepted: 01/09/2014] [Indexed: 10/25/2022]
Abstract
Evidence indicates that astronauts experience significant bone loss during space mission. Recently, we used the NASA developed rotary cell culture system (RCCS) to simulate microgravity (μXg) conditions and demonstrated increased osteoclastogenesis in mouse bone marrow cultures. Autophagy is a cellular recycling process of nutrients. Therefore, we hypothesize that μXg control of autophagy modulates osteoclastogenesis. Real-time PCR analysis of total RNA isolated from mouse bone marrow derived non-adherent cells subjected to modeled μXg showed a significant increase in autophagic marker Atg5, LC3 and Atg16L mRNA expression compared to ground based control (Xg) cultures. Western blot analysis of total cell lysates identified an 8.0-fold and 7.0-fold increase in the Atg5 and LC3-II expression, respectively. Confocal microscopy demonstrated an increased autophagosome formation in μXg subjected RAW 264.7 preosteoclast cells. RT(2) profiler PCR array screening for autophagy related genes identified that μXg upregulates intracellular signaling molecules associated with autophagy, autophagosome components and inflammatory cytokines/growth factors which coregulate autophagy in RAW 264.7 preosteoclast cells. Autophagy inhibitor, 3-methyladenine (3-MA) treatment of mouse bone marrow derived non-adherent mononuclear cells showed a significant decrease in μXg induced Atg5 and LC3 mRNA expression in the presence or absence of RANK ligand (RANKL) stimulation. Furthermore, RANKL treatment significantly increased (8-fold) p-CREB transcription factor levels under μXg as compared to Xg cultures and 3-MA inhibited RANKL increased p-CREB expression in these cells. Also, 3-MA suppresses μXg elevated osteoclast differentiation in mouse bone marrow cultures. Thus, our results suggest that μXg induced autophagy plays an important role in enhanced osteoclast differentiation and could be a potential therapeutic target to prevent bone loss in astronauts during space flight missions.
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Affiliation(s)
- Yuvaraj Sambandam
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Molly T Townsend
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Jason J Pierce
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Cecilia M Lipman
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA
| | - Azizul Haque
- Department of Microbiology & Immunology, Medical University of South Carolina, Charleston, SC, USA
| | - Ted A Bateman
- Department of Biomedical Engineering, University of North Carolina, Chapel Hill, NC, USA
| | - Sakamuri V Reddy
- Charles P. Darby Children's Research Institute, Medical University of South Carolina, Charleston, SC, USA.
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108
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Resveratrol protects astrocytes against traumatic brain injury through inhibiting apoptotic and autophagic cell death. Cell Death Dis 2014; 5:e1147. [PMID: 24675465 PMCID: PMC3973229 DOI: 10.1038/cddis.2014.123] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Revised: 02/11/2014] [Accepted: 02/24/2014] [Indexed: 12/22/2022]
Abstract
Traumatic brain injury (TBI) is often caused by accidents that damage the brain. TBI can induce glutamate excitotoxicity and lead to neuronal and glial cell death. In this study, we investigated the mechanism of cell death during the secondary damage caused by TBI in vivo and in vitro, as well as the protective effect of resveratrol (RV). Here we report that glycogen synthase kinase-3β (GSK-3β) activation and microtubule-associated protein light chain 3 processing were induced in rat brains exposed to TBI. In the in vitro TBI model, apoptotic and autophagic cell death were induced through glutamate-mediated GSK-3β activation in normal CTX TNA2 astrocytes. The GSK-3β inhibitor SB216763 or transfection of GSK-3β small-interfering RNA increases cell survival. By contrast, overexpression of GSK-3β enhanced glutamate excitotoxicity. Administration of RV reduced cell death in CTX TNA2 astrocytes by suppressing reactive oxygen species (ROS)-mediated GSK-3β activation, the mechanism by which RV also exerted protective effects in vivo. Mitochondrial damages, including the opening of mitochondrial permeability transition pore (MPTP) and mitochondrial depolarization, were induced by glutamate through the ROS/GSK-3β pathway. Moreover, cyclosporine A, an MPTP inhibitor, suppressed mitochondrial damage and the percentages of cells undergoing autophagy and apoptosis and thereby increased cell survival. Taken together, our results demonstrated that cell death occurring after TBI is induced through the ROS/GSK-3β/mitochondria signaling pathway and that administration of RV can increase cell survival by suppressing GSK-3β-mediated autophagy and apoptosis. Therefore, the results indicated that resveratrol may serve as a potential therapeutic agent in the treatment of TBI.
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109
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Moriyama M, Moriyama H, Uda J, Matsuyama A, Osawa M, Hayakawa T. BNIP3 plays crucial roles in the differentiation and maintenance of epidermal keratinocytes. J Invest Dermatol 2014; 134:1627-1635. [PMID: 24402046 DOI: 10.1038/jid.2014.11] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 12/10/2013] [Accepted: 12/18/2013] [Indexed: 12/13/2022]
Abstract
Transcriptome analysis of the epidermis of Hes1(-/-) mouse revealed the direct relationship between Hes1 (hairy and enhancer of split-1) and BNIP3 (BCL2 and adenovirus E1B 19-kDa-interacting protein 3), a potent inducer of autophagy. Keratinocyte differentiation is going along with activation of lysosomal enzymes and organelle clearance, expecting the contribution of autophagy in this process. We found that BNIP3 was expressed in the suprabasal layer of the epidermis, where autophagosome formation is normally observed. Forced expression of BNIP3 in human primary epidermal keratinocytes (HPEKs) resulted in autophagy induction and keratinocyte differentiation, whereas knockdown of BNIP3 had the opposite effect. Intriguingly, addition of an autophagy inhibitor significantly suppressed the BNIP3-stimulated differentiation of keratinocytes, suggesting that BNIP3 plays a crucial role in keratinocyte differentiation by inducing autophagy. Furthermore, the number of dead cells increased in the human epidermal equivalent of BNIP3 knockdown keratinocytes, which suggests that BNIP3 is important for maintenance of skin epidermis. Interestingly, although UVB irradiation stimulated BNIP3 expression and cleavage of caspase3, suppression of UVB-induced BNIP3 expression led to further increase in cleaved caspase3 levels. This suggests that BNIP3 has a protective effect against UVB-induced apoptosis in keratinocytes. Overall, our data provide valuable insights into the role of BNIP3 in the differentiation and maintenance of epidermal keratinocytes.
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Affiliation(s)
- Mariko Moriyama
- Pharmaceutical Research and Technology Institute, Kinki University, Higashi-Osaka, Osaka, Japan; Platform for Realization of Regenerative Medicine, Foundation for Biomedical Research and Innovation, Kobe, Hyogo, Japan
| | - Hiroyuki Moriyama
- Pharmaceutical Research and Technology Institute, Kinki University, Higashi-Osaka, Osaka, Japan.
| | - Junki Uda
- Pharmaceutical Research and Technology Institute, Kinki University, Higashi-Osaka, Osaka, Japan
| | - Akifumi Matsuyama
- Platform for Realization of Regenerative Medicine, Foundation for Biomedical Research and Innovation, Kobe, Hyogo, Japan
| | - Masatake Osawa
- Division of Regeneration Technology, Gifu University School of Medicine, Gifu, Gifu, Japan
| | - Takao Hayakawa
- Pharmaceutical Research and Technology Institute, Kinki University, Higashi-Osaka, Osaka, Japan
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110
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Shapiro IM, Layfield R, Lotz M, Settembre C, Whitehouse C. Boning up on autophagy: the role of autophagy in skeletal biology. Autophagy 2013; 10:7-19. [PMID: 24225636 DOI: 10.4161/auto.26679] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
From an evolutionary perspective, the major function of bone is to provide stable sites for muscle attachment and affording protection of vital organs, especially the heart and lungs (ribs) and spinal cord (vertebrae and intervertebral discs). However, bone has a considerable number of other functions: serving as a store for mineral ions, providing a site for blood cell synthesis and participating in a complex system-wide endocrine system. Not surprisingly, bone and cartilage cell homeostasis is tightly controlled, as is the maintenance of tissue structure and mass. While a great deal of new information is accruing concerning skeletal cell homeostasis, one relatively new observation is that the cells of bone (osteoclasts osteoblasts and osteocytes) and cartilage (chondrocytes) exhibit autophagy. The focus of this review is to examine the significance of this process in terms of the functional demands of the skeleton in health and during growth and to provide evidence that dysregulation of the autophagic response is involved in the pathogenesis of diseases of bone (Paget disease of bone) and cartilage (osteoarthritis and the mucopolysaccharidoses). Delineation of molecular changes in the autophagic process is uncovering new approaches for the treatment of diseases that affect the axial and appendicular skeleton.
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Affiliation(s)
- Irving M Shapiro
- Jefferson Medical College; Thomas Jefferson University; Philadelphia, PA USA
| | - Robert Layfield
- School of Life Sciences; University of Nottingham Medical School; Nottingham UK
| | - Martin Lotz
- Arthritis Research; The Scripps Research Institute; La Jolla, CA USA
| | - Carmine Settembre
- Telethon Institute of Genetics and Medicine (TIGEM); Naples, Italy; Department of Molecular and Human Genetics; Baylor College of Medicine, Houston, TXUSA and Jan and Dan Duncan Neurological Research Institute; Texas Children's Hospital; Houston, TX USA; Medical Genetics; Department of Translational and Medical Science; Federico II University; Naples, Italy
| | - Caroline Whitehouse
- Department of Medical and Molecular Genetics; Kings College London; London UK
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Al Hadi H, Smerdon GR, Fox SW. Hyperbaric oxygen therapy suppresses osteoclast formation and bone resorption. J Orthop Res 2013; 31:1839-44. [PMID: 23878004 DOI: 10.1002/jor.22443] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Accepted: 06/25/2013] [Indexed: 02/04/2023]
Abstract
The cellular and molecular mechanism through which hyperbaric oxygen therapy (HBO) improves osteonecrosis (ON) is unclear. The present study therefore examined the effect of HBO, pressure and hyperoxia on RANKL-induced osteoclast formation in RAW 264.7 cells and human peripheral blood monocytes (PBMC). Daily exposure to HBO (2.4 ATA, 97% O2 , 90 min), hyperbaric pressure (2.4 ATA, 8.8% O2 , 90 min) or normobaric hyperoxia (1 ATA, 95% O2 , 90 min) significantly decreased RANKL-induced osteoclast formation and bone resorption in normoxic conditions. HBO had a more pronounced anti-osteoclastic effect than hyperoxia or pressure alone and also directly inhibited osteoclast formation and resorption in hypoxic conditions a hallmark of many osteolytic skeletal disorders. The suppressive action of HBO was at least in part mediated through a reduction in RANK, NFATc1, and Dc-STAMP expression and inhibition of hypoxia-induced HIF-1α mRNA and protein expression. This data provides mechanistic evidence supporting the use of HBO as an adjunctive therapy to prevent osteoclast formation and bone loss associated with low oxygen partial pressure.
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Affiliation(s)
- Hadil Al Hadi
- School of Biomedical and Biological Sciences, Plymouth University, Drake Circus, Plymouth, Devon, PL4 8AA, UK
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112
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Abstract
Hematopoietic stem cells (HSCs) are inherently quiescent and self-renewing, yet can differentiate and commit to multiple blood cell types. Intracellular mitochondrial content is dynamic, and there is an increase in mitochondrial content during differentiation and lineage commitment in HSCs. HSCs reside in a hypoxic niche within the bone marrow and rely heavily on glycolysis, while differentiated and committed progenitors rely on oxidative phosphorylation. Increased oxidative phosphorylation during differentiation and commitment is not only due to increased mitochondrial content but also due to changes in mitochondrial cytosolic distribution and efficiency. These changes in the intracellular mitochondrial landscape contribute signals toward regulating differentiation and commitment. Thus, a functional relationship exists between the mitochondria in HSCs and the state of the HSCs (i.e., stemness vs. differentiated). This review focuses on how autophagy-mediated mitochondrial clearance (i.e., mitophagy) may affect HSC mitochondrial content, thereby influencing the fate of HSCs and maintenance of hematopoietic homeostasis.
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Affiliation(s)
- Aashish Joshi
- Department of Pathology; St. Jude Children's Research Hospital; Memphis, TN USA
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113
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Chen G, Zhang W, Li YP, Ren JG, Xu N, Liu H, Wang FQ, Sun ZJ, Jia J, Zhao YF. Hypoxia-induced autophagy in endothelial cells: a double-edged sword in the progression of infantile haemangioma? Cardiovasc Res 2013; 98:437-48. [PMID: 23408345 DOI: 10.1093/cvr/cvt035] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
AIMS The aim of this study was to investigate the precise role of hypoxia-induced autophagy in endothelial cells, and whether it contributes to the distinctive progression of infantile haemangioma (IH). METHODS AND RESULTS The endothelial cells (EOMA and HUVECs) were cultured under hypoxic conditions for indicated times (0-72 h). The results showed that short exposure of the endothelial cells to hypoxia resulted in increased cell survival and proliferation, accompanied by occurrence of autophagy. Prolonged hypoxia-induced autophagy, correlating with increased cell death, was also detected afterwards. Correspondingly, autophagy inhibition prevented the enhanced cell survival and proliferation capacity, advanced the occurrence of cell-death in early hypoxic stage, and meanwhile attenuated the ability of prolonged hypoxia in cell-death induction. Moreover, our data demonstrated that the functional transformation of hypoxia-induced autophagy, pro-survival to pro-death, was rigorously regulated by the switch between hypoxia-inducible factor-1α (HIF-1α) and mammalian target of rapamycin (mTOR) pathways. Importantly, we also revealed the activation levels of HIF-1α and mTOR, as well as the autophagy status during the progression of IH. CONCLUSION This study unmasks the functional switch between HIF-1α and mTOR in regulating hypoxia-induced autophagy in endothelial cells and, more importantly, indicates its potential role in the progression of IH.
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Affiliation(s)
- Gang Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan 430071, China
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114
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Orrenius S, Kaminskyy VO, Zhivotovsky B. Autophagy in toxicology: cause or consequence? Annu Rev Pharmacol Toxicol 2012; 53:275-97. [PMID: 23072380 DOI: 10.1146/annurev-pharmtox-011112-140210] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Research on autophagy and its effects on cell metabolism and physiology has increased dramatically during recent years. Multiple forms of autophagy have been characterized, and many of the genes involved in the regulation of this process have been identified. The importance of autophagy for embryonic development and maintenance of tissue homeostasis in the adult organism has been demonstrated convincingly, and several human diseases have been linked to deficiencies in autophagy. Most often, autophagy serves as a protective mechanism, but persistent activation of autophagy can result in cell death. This is true for many toxic agents. In fact, there are ample examples of cross talk between autophagy and other modes of cell death after exposure to toxicants. However, the relative contribution of autophagy to the overall toxicity of these compounds is not always clear, and further research is needed to clarify the toxicological significance of this process.
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Affiliation(s)
- Sten Orrenius
- Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, SE-17177 Stockholm, Sweden.
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115
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Mazzio E, Soliman KFA. Whole genome expression profile in neuroblastoma cells exposed to 1-methyl-4-phenylpyridine. Neurotoxicology 2012; 33:1156-69. [PMID: 22776087 PMCID: PMC3470775 DOI: 10.1016/j.neuro.2012.06.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Revised: 06/18/2012] [Accepted: 06/22/2012] [Indexed: 11/18/2022]
Abstract
Mitochondrial dysfunction and subsequent energy failure is a contributing factor to degeneration of the substantia nigra pars compacta associated with Parkinson's disease (PD). In this study, we investigate molecular events triggered by cell exposure to the mitochondrial toxin 1-methyl-4-phenylpyridine (MPP+) using whole genome-expression microarray, Western Blot and metabolic studies. The data show that MPP+ (500 μM) obstructs mitochondrial respiration/oxidative phosphorylation (OXPHOS) in mouse neuroblastoma Neuro-2a cells, juxtaposing accelerated glucose consumption and production of lactic acid. While additional glucose concentrations restored viability in the presence of MPP+ (500 μM), the loss of OXPHOS was sustained, suggesting that compensatory anaerobic metabolic systems were fulfilling required energy needs. Under these conditions, MPP+ initiated significant changes to the transcription of 439 genes of which 287 DAVID IDs were identified and subsequent functional annotation clusters identified. Prominent changes were as follows; MPP+ initiated loss of mRNA for mitochondrial encoded 3-hydroxybutyratedehydrogenase, type 2(Bdh2), tv1, NADH dehydrogenase 4,5 genes, cytochrome b and NADH dehydrogenase (ubiquinone) flavoprotein 3, concomitant to rise in a mitochondrial fission gene; ganglioside-induced differentiation-associated-protein 1 (GDAP1). The negative changes to OXPHOS components were accompanied by protective forces within the mitochondria espousing elevated ratio of anti/pro-apoptotic processes. These included a loss of apoptotic Bcl-2/adenovirus E1B 19-kDa-interacting protein (BNIP3) and family with sequence similarity 162, member A (FAM162a) and rise of heat shock protein 1 and Lon peptidase 1. There were no changes indicative of free radical damage (e.g. SOD, GSH-Px), rather MPP+ initiated significant elevation in G protein signaling components (which trigger catabolic processes) and anaerobic metabolic systems involving carboxylic acid/transamination reactions (e.g. glutamate oxaloacetate transaminase 1 (GOT1), glutamic pyruvate-alanine transaminase 2 (GPT2), cystathionase and redox proteins such as cytochrome b5 reductase 1 and ferredoxin reductase. Counter-intuitively, the data show reduction of mRNA in glycolytic processes [DAVID enrichment score 9.96 p value 1.90E-19], some corroborated by Western Blot, bringing in to question the sources of lactate observed in the presence of MPP+. Examining this aspect, the data show that diverse carboxylic acids (succinate, oxaloacetate and a-ketoglutarate) are capable of contributing to the lactate pool in addition to phosph(enolpyruvate) or pyruvate in the absence of glucose by this cell line. In conclusion, these findings show that MPP+ negatively affects the transcriptome involved with complex I, but initiated an elevation of G protein signaling and anaerobic metabolic systems involved with nitrogen/carboxylic acid metabolism. Future research will be required to elucidate the survival pathways that drive anaerobic substrate level phosphorylation, and define functional ramification to the loss of mitochondrial FAM162a and BNIP3 proteins.
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Affiliation(s)
- E Mazzio
- College of Pharmacy and Pharmaceutical Sciences, Florida A & M University, Tallahassee, Florida 32307, USA
| | - KFA Soliman
- College of Pharmacy and Pharmaceutical Sciences, Florida A & M University, Tallahassee, Florida 32307, USA
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116
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Abstract
Imbalances between bone resorption and formation lie at the root of disorders such as osteoporosis, Paget's disease of bone (PDB), and osteopetrosis. Recently, genetic and functional studies have implicated proteins involved in autophagic protein degradation as important mediators of bone cell function in normal physiology and in pathology. Autophagy is the conserved process whereby aggregated proteins, intracellular pathogens, and damaged organelles are degraded and recycled. This process is important both for normal cellular quality control and in response to environmental or internal stressors, particularly in terminally-differentiated cells. Autophagic structures can also act as hubs for the spatial organization of recycling and synthetic process in secretory cells. Alterations to autophagy (reduction, hyperactivation, or impairment) are associated with a number of disorders, including neurodegenerative diseases and cancers, and are now being implicated in maintenance of skeletal homoeostasis. Here, we introduce the topic of autophagy, describe the new findings that are starting to emerge from the bone field, and consider the therapeutic potential of modifying this pathway for the treatment of age-related bone disorders.
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Affiliation(s)
- Lynne J Hocking
- Musculoskeletal Research Programme, Division of Applied Medicine, University of Aberdeen, Aberdeen, UK.
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117
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Pratt J, Roy R, Annabi B. Concanavalin-A-induced autophagy biomarkers requires membrane type-1 matrix metalloproteinase intracellular signaling in glioblastoma cells. Glycobiology 2012; 22:1245-55. [PMID: 22692046 DOI: 10.1093/glycob/cws093] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Pre-clinical trials for cancer therapeutics support the anti-neoplastic properties of the lectin from Canavalia ensiformis (Concanavalin-A, ConA) in targeting apoptosis and autophagy in a variety of cancer cells. Given that membrane type-1 matrix metalloproteinase (MT1-MMP), a plasma membrane-anchored matrix metalloproteinase, is a glycoprotein strongly expressed in radioresistant and chemoresistant glioblastoma that mediates pro-apoptotic signalling in brain cancer cells, we investigated whether MT1-MMP could also signal autophagy. Among the four lectins tested, we found that the mannopyranoside/glucopyranoside-binding ConA, which is also well documented to trigger MT1-MMP expression, increases autophagic acidic vacuoles formation as demonstrated by Acridine Orange cell staining. Although siRNA-mediated MT1-MMP gene silencing effectively reversed ConA-induced autophagy, inhibition of the MT1-MMP extracellular catalytic function with Actinonin or Ilomastat did not. Conversely, direct overexpression of the recombinant Wt-MT1-MMP protein triggered proMMP-2 activation and green fluorescent protein-microtubule-associated protein light chain 3 puncta indicative of autophagosomes formation, while deletion of MT1-MMP's cytoplasmic domain disabled such autophagy induction. ConA-treated U87 cells also showed an upregulation of BNIP3 and of autophagy-related gene members autophagy-related protein 3, autophagy-related protein 12 and autophagy-related protein 16-like 1, where respective inductions were reversed when MT1-MMP gene expression was silenced. Altogether, we provide molecular evidence supporting the pro-autophagic mechanism of action of ConA in glioblastoma cells. We also highlight new signal transduction functions of MT1-MMP within apoptotic and autophagic pathways that often characterize cancer cell responses to chemotherapeutic drugs.
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Affiliation(s)
- Jonathan Pratt
- Laboratoire d'Oncologie Moléculaire, Centre de Recherche BioMED, Québec, Canada
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118
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Chen G, Hu X, Zhang W, Xu N, Wang FQ, Jia J, Zhang WF, Sun ZJ, Zhao YF. Mammalian target of rapamycin regulates isoliquiritigenin-induced autophagic and apoptotic cell death in adenoid cystic carcinoma cells. Apoptosis 2012; 17:90-101. [PMID: 21956714 DOI: 10.1007/s10495-011-0658-1] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previous studies, including those from our laboratory, have demonstrated that isoliquiritigenin (ISL), a flavonoid isolated from licorice, is a promising cancer chemotherapeutic agent. However the mechanisms underlying its anticancer effects are still far from clear. We now show, for the first time, that ISL triggers the mammalian target of rapamycin (mTOR)-dependent autophagic and apoptotic cell death in adenoid cystic carcinoma (ACC). Exposure of both ACC-2 and ACC-M cells to ISL resulted in several specific features for autophagy, including the appearance of membranous vacuoles, formation of acidic vesicular organelles, punctate pattern of LC3 immunostaining, and an increase in autophagic flux. Moreover, ISL treatment also resulted in significantly increased apoptosis in ACC cells. The ISL-mediated autophagic and apoptotic cell death were obviously attenuated by transfection with dominant negative Atg5 (DN-Atg5(K130R)) plasmids or treatment with 3-methyladenine(3-MA). In additon, the data also revealed that the autophagic and apoptotic cell death induced by ISL occurred through a mTOR-dependent pathway. More importantly, the xenograft model using ACC-M cells provided further evidence of the occurrence of ISL-induced autophagy and apoptosis in vivo, correlating with the suppresson of mTOR activation as well as up-regulation of Atg5 expression. Taken together, these findings in our study suggest that induction of mTOR-dependent autophagic and apoptotic cell death may be an important mechanism in cancer chemotherapy by ISL.
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Affiliation(s)
- Gang Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST), Key Laboratory of Oral Biomedicine Ministry of Education, Department of Oral and Maxillofacial Surgery, School & Hospital of Stomatology, Wuhan University, Wuhan, China
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119
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Kolattukudy PE, Niu J. Inflammation, endoplasmic reticulum stress, autophagy, and the monocyte chemoattractant protein-1/CCR2 pathway. Circ Res 2012; 110:174-89. [PMID: 22223213 DOI: 10.1161/circresaha.111.243212] [Citation(s) in RCA: 193] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Numerous inflammatory cytokines have been implicated in the pathogenesis of cardiovascular diseases. Monocyte chemoattractant protein (MCP)-1/CCL2 is expressed by mainly inflammatory cells and stromal cells such as endothelial cells, and its expression is upregulated after proinflammatory stimuli and tissue injury. MCP-1 can function as a traditional chemotactic cytokine and also regulates gene transcription. The recently discovered novel zinc-finger protein, called MCPIP (MCP-1-induced protein), initiates a series of signaling events that causes oxidative and endoplasmic reticulum (ER) stress, leading to autophagy that can result in cell death or differentiation, depending on the cellular context. After a brief review of the basic processes involved in inflammation, ER stress, and autophagy, the recently elucidated role of MCP-1 and MCPIP in inflammatory diseases is reviewed. MCPIP was found to be able to control inflammatory response by inhibition of nuclear factor-κB activation through its deubiquitinase activity or by degradation of mRNA encoding a set of inflammatory cytokines through its RNase activity. The potential inclusion of such a novel deubiquitinase in the emerging anti-inflammatory strategies for the treatment of inflammation-related diseases such as cardiovascular diseases and type 2 diabetes is briefly discussed.
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Affiliation(s)
- Pappachan E Kolattukudy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32816, USA.
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120
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Affiliation(s)
- Hans-Uwe Simon
- From the Institute of Pharmacology, University of Bern, Bern, Switzerland
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121
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Vessoni AT, Muotri AR, Okamoto OK. Autophagy in stem cell maintenance and differentiation. Stem Cells Dev 2012; 21:513-20. [PMID: 22066548 DOI: 10.1089/scd.2011.0526] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Autophagy is a lysosome-dependent degradation pathway that allows cells to recycle damaged or superfluous cytoplasmic content, such as proteins, organelles, and lipids. As a consequence of autophagy, the cells generate metabolic precursors for macromolecular biosynthesis or ATP generation. Deficiencies in this pathway were associated to several pathological conditions, such as neurodegenerative and cardiac diseases, cancer, and aging. The aim of this review is to summarize recent discoveries showing that autophagy also plays a critical role in stem cell maintenance and in a variety of cell differentiation processes. We also discuss a possible role for autophagy during cellular reprogramming and induced pluripotent stem (iPS) cell generation by taking advantage of ATP generation for chromatin remodeling enzyme activity and mitophagy. Finally, the significance of autophagy modulation is discussed in terms of augmenting efficiency of iPS cell generation and differentiation processes.
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Affiliation(s)
- Alexandre Teixeira Vessoni
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
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122
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McManus S, Roux S. The adaptor protein p62/SQSTM1 in osteoclast signaling pathways. J Mol Signal 2012; 7:1. [PMID: 22216904 PMCID: PMC3309942 DOI: 10.1186/1750-2187-7-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/04/2012] [Indexed: 02/07/2023] Open
Abstract
Paget's disease of bone (PDB) is a skeletal disorder characterized by focal and disorganized increases in bone turnover and overactive osteoclasts. The discovery of mutations in the SQSTM1/p62 gene in numerous patients has identified protein p62 as an important modulator of bone turnover. In both precursors and mature osteoclasts, the interaction between receptor activator of NF-κB ligand (RANKL) and its receptor RANK results in signaling cascades that ultimately activate transcription factors, particularly NF-κB and NFATc1, promoting and regulating the osteoclast differentiation, activity, and survival. As a scaffold with multiple protein-protein interaction motifs, p62 is involved in virtually all the RANKL-activated osteoclast signaling pathways, along with being implicated in numerous other cellular processes. The p62 adaptor protein is one of the functional links reported between RANKL and TRAF6-mediated NF-κB activation, and also plays a major role as a shuttling factor that targets polyubiquitinated proteins for degradation by either the autophagy or proteasome pathways. The dysregulated expression and/or activity of p62 in bone disease up-regulates osteoclast functions. This review aims to outline and summarize the role of p62 in RANKL-induced signaling pathways and in ubiquitin-mediated signaling in osteoclasts, and the impact of PDB-associated p62 mutations on these processes.
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Affiliation(s)
- Stephen McManus
- Division of Rheumatology, Faculty of Medicine, University of Sherbrooke, 3001, 12th Avenue North, Sherbrooke, PQ, Canada.
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123
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High Beclin 1 expression defines a poor prognosis in endometrial adenocarcinomas. Gynecol Oncol 2011; 123:147-51. [DOI: 10.1016/j.ygyno.2011.06.023] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 05/28/2011] [Accepted: 06/16/2011] [Indexed: 01/13/2023]
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