1
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Smith SS, Young AMH, Davies BM, Takahashi H, Allinson KSJ, Kotter MRN. Evidence of impaired macroautophagy in human degenerative cervical myelopathy. Sci Rep 2022; 12:11873. [PMID: 35831377 PMCID: PMC9279443 DOI: 10.1038/s41598-022-15158-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 06/20/2022] [Indexed: 11/23/2022] Open
Abstract
Degenerative cervical myelopathy (DCM) is a common progressive disease of the spinal cord which can cause tetraplegia. Despite its prevalence, few studies have investigated the pathophysiology of DCM. Macroautophagy is a cellular process which degrades intracellular contents and its disruption is thought to contribute to many neurodegenerative diseases. The present study tests the hypothesis that macroautophagy is impaired in DCM. To address this, we utilised a collection of post-mortem cervical spinal cord samples and investigated seven DCM cases and five human controls. Immunohistochemical staining was used to visualise proteins involved in autophagy. This demonstrated significantly reduced numbers of LC3 puncta in cases versus controls (p = 0.0424). Consistent with reduced autophagy, we identified large aggregates of p62 in four of seven cases and no controls. Tau was increased in two of five cases compared to controls. BCL-2 was significantly increased in cases versus controls (p = 0.0133) and may explain this reduction in autophagy. Increased BCL-2 (p = 0.0369) and p62 bodies (p = 0.055) were seen in more severe cases of DCM. This is the first evidence that autophagy is impaired in DCM; the impairment appears greater in more severe cases. Further research is necessary to investigate whether macroautophagy has potential as a therapeutic target in DCM.
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Affiliation(s)
- Sam S Smith
- School of Clinical Medicine, University of Cambridge, Cambridge, UK
| | - Adam M H Young
- Academic Neurosurgery Unit, Department of Clinical Neurosurgery, University of Cambridge, Cambridge, UK
| | - Benjamin M Davies
- Academic Neurosurgery Unit, Department of Clinical Neurosurgery, University of Cambridge, Cambridge, UK
| | - Hitoshi Takahashi
- Department of Pathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Kieren S J Allinson
- Cambridge University Hospitals NHS Foundation Trust and the Cambridge Brain Bank, Cambridge, UK
| | - Mark R N Kotter
- Academic Neurosurgery Unit, Department of Clinical Neurosurgery, University of Cambridge, Cambridge, UK.
- WT MRC Cambridge Stem Cell Institute, Anne McLaren Laboratory, University of Cambridge, Cambridge, UK.
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2
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Liao HY, Wang ZQ, Ran R, Zhou KS, Ma CW, Zhang HH. Biological Functions and Therapeutic Potential of Autophagy in Spinal Cord Injury. Front Cell Dev Biol 2022; 9:761273. [PMID: 34988074 PMCID: PMC8721099 DOI: 10.3389/fcell.2021.761273] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/24/2021] [Indexed: 12/12/2022] Open
Abstract
Autophagy is an evolutionarily conserved lysosomal degradation pathway that maintains metabolism and homeostasis by eliminating protein aggregates and damaged organelles. Many studies have reported that autophagy plays an important role in spinal cord injury (SCI). However, the spatiotemporal patterns of autophagy activation after traumatic SCI are contradictory. Most studies show that the activation of autophagy and inhibition of apoptosis have neuroprotective effects on traumatic SCI. However, reports demonstrate that autophagy is strongly associated with distal neuronal death and the impaired functional recovery following traumatic SCI. This article introduces SCI pathophysiology, the physiology and mechanism of autophagy, and our current review on its role in traumatic SCI. We also discuss the interaction between autophagy and apoptosis and the therapeutic effect of activating or inhibiting autophagy in promoting functional recovery. Thus, we aim to provide a theoretical basis for the biological therapy of SCI.
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Affiliation(s)
- Hai-Yang Liao
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Zhi-Qiang Wang
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Rui Ran
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Kai-Sheng Zhou
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Chun-Wei Ma
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
| | - Hai-Hong Zhang
- Lanzhou University Second Hospital, Lanzhou, China.,Department of Orthopaedics, Lanzhou University Second Hospital, Lanzhou, China
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3
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Wu Q, Xiang Z, Ying Y, Huang Z, Tu Y, Chen M, Ye J, Dou H, Sheng S, Li X, Ying W, Zhu S. Nerve growth factor (NGF) with hypoxia response elements loaded by adeno-associated virus (AAV) combined with neural stem cells improve the spinal cord injury recovery. Cell Death Discov 2021; 7:301. [PMID: 34675188 PMCID: PMC8531363 DOI: 10.1038/s41420-021-00701-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 10/03/2021] [Accepted: 10/08/2021] [Indexed: 12/21/2022] Open
Abstract
The ischemia and hypoxia microenvironment after spinal cord injury (SCI) makes SCI repair a challenging problem. With various stimulus, chances for neural stem cells (NSCs) to differentiate into neurons, astrocytes, oligodendrocytes are great and is considered as a potential source of the stem cell therapy to SCI. Our research used adeno-associated virus (AAV) to carry the target gene to transfect neural stem cells. Transfected NSCs can express nerve growth factor (NGF) navigated by five hypoxia-responsive elements (5HRE). Therefore, the 5HRE-NGF-NSCs could express NGF specifically in hypoxia sites to promote the tissue repair and function recovery. Based on the regeneration of neurocytes and promotion of the recovery found in SCI models, via locomotor assessment, histochemical staining and molecular examinations, our results demonstrated that 5HRE-NGF-NSCs could improve the motor function, neurons survival and molecules expression of SCI rats. Meanwhile, the downregulated expression of autophagy-related proteins indicated the inhibitive effect of 5HRE-NGF-NSCs on autophagy. Our research showed that 5HRE-NGF-NSCs contribute to SCI repair which might via inhibiting autophagy and improving the survival rate of neuronal cells. The new therapy also hampered the hyperplasia of neural glial scars and induced axon regeneration. These positive functions of 5HRE-NGF-NSCs all indicate a promising SCI treatment.
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Affiliation(s)
- Qiuji Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Ziyue Xiang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yibo Ying
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Zhiyang Huang
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yurong Tu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Min Chen
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jiahui Ye
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Haicheng Dou
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Sunren Sheng
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xiaoyang Li
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Weiyang Ying
- Department of Pain Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
| | - Sipin Zhu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
- Second Medical College of Wenzhou Medical University, Wenzhou, Zhejiang, China.
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4
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Zhu S, Ying Y, Ye J, Chen M, Wu Q, Dou H, Ni W, Xu H, Xu J. AAV2-mediated and hypoxia response element-directed expression of bFGF in neural stem cells showed therapeutic effects on spinal cord injury in rats. Cell Death Dis 2021; 12:274. [PMID: 33723238 PMCID: PMC7960741 DOI: 10.1038/s41419-021-03546-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 12/12/2022]
Abstract
Neural stem cell (NSCs) transplantation has been one of the hot topics in the repair of spinal cord injury (SCI). Fibroblast growth factor (FGF) is considered a promising nerve injury therapy after SCI. However, owing to a hostile hypoxia condition in SCI, there remains a challenging issue in implementing these tactics to repair SCI. In this report, we used adeno-associated virus 2 (AAV2), a prototype AAV used in clinical trials for human neuron disorders, basic FGF (bFGF) gene under the regulation of hypoxia response element (HRE) was constructed and transduced into NSCs to yield AAV2-5HRE-bFGF-NSCs. Our results showed that its treatment yielded temporally increased expression of bFGF in SCI, and improved scores of functional recovery after SCI compared to vehicle control (AAV2-5HRE-NSCs) based on the analyses of the inclined plane test, Basso-Beattie-Bresnahan (BBB) scale and footprint analysis. Mechanistic studies showed that AAV2-5HRE-bFGF-NSCs treatment increased the expression of neuron-specific neuronal nuclei protein (NeuN), neuromodulin GAP43, and neurofilament protein NF200 while decreased the expression of glial fibrillary acidic protein (GFAP) as compared to the control group. Further, the expressions of autophagy-associated proteins LC3-II and Beclin 1 were decreased, whereas the expression of P62 protein was increased in AAV2-5HRE-bFGF-NSCs treatment group. Taken together, our data indicate that AAV2-5HRE-bFGF-NSCs treatment improved the recovery of SCI rats, which is accompanied by evidence of nerve regeneration, and inhibition of SCI-induced glial scar formation and cell autophagy. Thus, this study represents a step forward towards the potential use of AAV2-5HRE-bFGF-NSCs for future clinical trials of SCI repair.
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Affiliation(s)
- Sipin Zhu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China.
- The Second School of Medicine, Wenzhou Medical University, 325027, Wenzhou, China.
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, 6009, Australia.
| | - Yibo Ying
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
- The Second School of Medicine, Wenzhou Medical University, 325027, Wenzhou, China
| | - Jiahui Ye
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
- The Second School of Medicine, Wenzhou Medical University, 325027, Wenzhou, China
| | - Min Chen
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
- The Second School of Medicine, Wenzhou Medical University, 325027, Wenzhou, China
| | - Qiuji Wu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
- The Second School of Medicine, Wenzhou Medical University, 325027, Wenzhou, China
| | - Haicheng Dou
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Wenfei Ni
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Huazi Xu
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, 325000, Zhejiang, China
| | - Jiake Xu
- School of Biomedical Sciences, The University of Western Australia, Perth, WA, 6009, Australia.
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5
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Ondrej M, Cechakova L, Fabrik I, Klimentova J, Tichy A. Lys05 - A Promising Autophagy Inhibitor in the Radiosensitization Battle: Phosphoproteomic Perspective. Cancer Genomics Proteomics 2021; 17:369-382. [PMID: 32576582 DOI: 10.21873/cgp.20196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Autophagy is a crucial factor contributing to radioresistance during radiotherapy. Although Lys05 has proven its ability to improve the results of radiotherapy through the inhibition of autophagy, molecular mechanisms of this inhibition remain elusive. We aimed to describe the molecular mechanisms involved in Lys05-induced inhibition of autophagy. MATERIALS AND METHODS Radioresistant human non-small cell lung carcinoma cells (H1299, p53-negative) and methods of quantitative phosphoproteomics were employed to define the molecular mechanisms involved in Lys05-induced inhibition of autophagy. RESULTS We confirmed that at an early stage after irradiation, autophagy was induced, whereas at a later stage after irradiation, it was inhibited. The early-stage induction of autophagy was characterized mainly by the activation of biosynthetic and metabolic processes through up- or down-regulation of the critical autophagic regulatory proteins Sequestosome-1 (SQSTM1) and proline-rich AKT1 substrate 1 (AKT1S1). The late-stage inhibition of autophagy was attributed mainly to down-regulation of Unc-51 like autophagy-activating kinase 1 (ULK1) through phosphorylation at Ser638. CONCLUSION This work contributes to emerging phosphoproteomic insights into autophagy-mediated global signaling in lung cancer cells, which might consequently facilitate the development of precision medicine therapeutics.
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Affiliation(s)
- Martin Ondrej
- Department of Radiobiology, Faculty of Military Health Sciences, University of Defense in Brno, Hradec Kralove, Czech Republic
| | - Lucie Cechakova
- Department of Radiobiology, Faculty of Military Health Sciences, University of Defense in Brno, Hradec Kralove, Czech Republic
| | - Ivo Fabrik
- Department of Molecular Biology and Pathology, Faculty of Military Health Sciences, University of Defense in Brno, Hradec Kralove, Czech Republic
| | - Jana Klimentova
- Department of Molecular Biology and Pathology, Faculty of Military Health Sciences, University of Defense in Brno, Hradec Kralove, Czech Republic
| | - Ales Tichy
- Department of Radiobiology, Faculty of Military Health Sciences, University of Defense in Brno, Hradec Kralove, Czech Republic
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6
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Tran AP, Warren PM, Silver J. Regulation of autophagy by inhibitory CSPG interactions with receptor PTPσ and its impact on plasticity and regeneration after spinal cord injury. Exp Neurol 2020; 328:113276. [PMID: 32145250 DOI: 10.1016/j.expneurol.2020.113276] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 12/15/2022]
Abstract
Chondroitin sulfate proteoglycans (CSPGs), extracellular matrix molecules that increase dramatically following a variety of CNS injuries or diseases, have long been known for their potent capacity to curtail cell migrations as well as axon regeneration and sprouting. The inhibition can be conferred through binding to their major cognate receptor, Protein Tyrosine Phosphatase Sigma (PTPσ). However, the precise mechanisms downstream of receptor binding that mediate growth inhibition have remained elusive. Recently, CSPGs/PTPσ interactions were found to regulate autophagic flux at the axon growth cone by dampening the autophagosome-lysosomal fusion step. Because of the intense interest in autophagic phenomena in the regulation of a wide variety of critical cellular functions, we summarize here what is currently known about dysregulation of autophagy following spinal cord injury, and highlight this critical new mechanism underlying axon regeneration failure. Furthermore, we review how CSPGs/PTPσ interactions influence plasticity through autophagic regulation and how PTPσ serves as a switch to execute either axon outgrowth or synaptogenesis. This has exciting implications for the role CSPGs play not only in axon regeneration failure after spinal cord injury, but also in neurodegenerative diseases where, again, inhibitory CSPGs are upregulated.
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Affiliation(s)
- Amanda Phuong Tran
- Seattle Children's Hospital Research Institute, Integrative Center for Brain Research, Seattle, Washington, USA
| | - Philippa Mary Warren
- King's College London, Regeneration Group, The Wolfson Centre for Age-Related Diseases, Guy's Campus, London Bridge, London, UK
| | - Jerry Silver
- Case Western Reserve University, School of Medicine, Department of Neurosciences, Cleveland, OH, USA.
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7
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Ray SK. Modulation of autophagy for neuroprotection and functional recovery in traumatic spinal cord injury. Neural Regen Res 2020; 15:1601-1612. [PMID: 32209759 PMCID: PMC7437603 DOI: 10.4103/1673-5374.276322] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Spinal cord injury (SCI) is a serious central nervous system trauma that leads to loss of motor and sensory functions in the SCI patients. One of the cell death mechanisms is autophagy, which is 'self-eating' of the damaged and misfolded proteins and nucleic acids, damaged mitochondria, and other impaired organelles for recycling of cellular building blocks. Autophagy is different from all other cell death mechanisms in one important aspect that it gives the cells an opportunity to survive or demise depending on the circumstances. Autophagy is a therapeutic target for alleviation of pathogenesis in traumatic SCI. However, functions of autophagy in traumatic SCI remain controversial. Spatial and temporal patterns of activation of autophagy after traumatic SCI have been reported to be contradictory. Formation of autophagosomes following therapeutic activation or inhibition of autophagy flux is ambiguous in traumatic SCI studies. Both beneficial and harmful outcomes due to enhancement autophagy have been reported in traumatic SCI studies in preclinical models. Only further studies will make it clear whether therapeutic activation or inhibition of autophagy is beneficial in overall outcomes in preclinical models of traumatic SCI. Therapeutic enhancement of autophagy flux may digest the damaged components of the central nervous system cells for recycling and thereby facilitating functional recovery. Many studies demonstrated activation of autophagy flux and inhibition of apoptosis for neuroprotective effects in traumatic SCI. Therapeutic induction of autophagy in traumatic SCI promotes axonal regeneration, supporting another beneficial role of autophagy in traumatic SCI. In contrast, some other studies demonstrated that disruption of autophagy flux in traumatic SCI strongly correlated with neuronal death at remote location and impaired functional recovery. This article describes our current understanding of roles of autophagy in acute and chronic traumatic SCI, cross-talk between autophagy and apoptosis, therapeutic activation or inhibition of autophagy for promoting functional recovery, and future of autophagy in traumatic SCI.
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Affiliation(s)
- Swapan K. Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA,Correspondence to: Swapan K. Ray, .
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8
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Bajić SS, Đokić J, Dinić M, Tomić S, Popović N, Brdarić E, Golić N, Tolinački M. GABA potentiate the immunoregulatory effects of Lactobacillus brevis BGZLS10-17 via ATG5-dependent autophagy in vitro. Sci Rep 2020; 10:1347. [PMID: 31992761 PMCID: PMC6987229 DOI: 10.1038/s41598-020-58177-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 01/13/2020] [Indexed: 01/11/2023] Open
Abstract
The characterization of mechanisms involved in the positive effects of probiotic bacteria in various pathophysiological conditions is a prerogative for their safe and efficient application in biomedicine. We have investigated the immunological effects of live bacteria-free supernatant collected from GABA-producing Lactobacillus brevis BGZLS10-17 on Concanavalin A-stimulated mesenteric lymph node cells (MLNC), an in vitro model of activated immune cells. We have shown that GABA containing and GABA-free supernatant of Lactobacillus brevis BGZLS10-17 have strong immunoregulatory effects on MLNC. Further, GABA produced by this strain exhibit additional inhibitory effects on proliferation, IFN-γ and IL-17 production by MLNC, and the expression of MHCII and CD80 on antigen presenting cells. At the other hand, GABA-containing supernatants displayed the strongest stimulatory effects on the expression of immunoregulatory molecules, such as Foxp3+, IL-10, TGF-β, CTLA4 and SIRP-α. By looking for the mechanisms of actions, we found that supernatants produced by BGZLS10-17 induce autophagy in different MLNC, such as CD4+ and CD8+ T lymphocytes, NK and NKT cells, as well as antigen presenting cells. Further, we showed that the stimulation of Foxp3+, IL-10 and TGF-β expression by BGZLS10-17 produced GABA is completely mediated by the induction of ATG5 dependent autophagy, and that other molecules in the supernatants display GABA-, ATG5-, Foxp3+-, IL-10- and TGF-β- independent, immunoregulatory effects.
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Affiliation(s)
- Svetlana Soković Bajić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
| | - Jelena Đokić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia.
| | - Miroslav Dinić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
| | - Sergej Tomić
- Department for Immunology and Immunoparasitology, Institute for the Application of Nuclear Energy, University of Belgrade, Belgrade, Serbia
| | - Nikola Popović
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
| | - Emilija Brdarić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
| | - Nataša Golić
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
| | - Maja Tolinački
- Laboratory for Molecular Microbiology (LMM), Institute of Molecular Genetics and Genetic Engineering (IMGGI), University of Belgrade, Belgrade, Serbia
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9
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Memmert S, Nogueira AVB, Damanaki A, Nokhbehsaim M, Rath-Deschner B, Götz W, Gölz L, Cirelli JA, Till A, Jäger A, Deschner J. Regulation of the autophagy-marker Sequestosome 1 in periodontal cells and tissues by biomechanical loading. J Orofac Orthop 2019; 81:10-21. [PMID: 31591651 DOI: 10.1007/s00056-019-00197-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 08/20/2019] [Indexed: 01/24/2023]
Abstract
PURPOSE Orthodontic treatment is based on the principle of force application to teeth and subsequently to the surrounding tissues and periodontal cells. Sequestosome 1 (SQSTM1) is a well-known marker for autophagy, which is an important cellular mechanism of adaptation to stress. The aim of this study was to analyze whether biomechanical loading conditions regulate SQSTM1 in periodontal cells and tissues, thereby providing further information on the role of autophagy in orthodontic tooth movement. METHODS Periodontal ligament (PDL) fibroblasts were exposed to cyclic tensile strain of low magnitude (3%, CTSL), and the regulation of autophagy-associated targets was determined with an array-based approach. SQSTM1 was selected for further biomechanical loading experiments with dynamic and static tensile strain and assessed via real-time polymerase chain reaction (RT-PCR) and immunoblotting. Signaling pathways involved in SQSTM1 activation were analyzed by using specific inhibitors, including an autophagy inhibitor. Finally, SQSTM1 expression was analyzed in gingival biopsies and histological sections of rats in presence and absence of orthodontic forces. RESULTS Multiple autophagy-associated targets were regulated by CTSL in PDL fibroblasts. All biomechanical loading conditions tested increased the SQSTM1 expression significantly. Stimulatory effects of CTSL on SQSTM1 expression were diminished by inhibition of the c‑Jun N‑terminal kinase (JNK) pathway and of autophagy. Increased SQSTM1 levels after CTSL were confirmed by immunoblotting. Orthodontic force application also led to significantly elevated SQTSM1 levels in the gingiva and PDL of treated animals as compared to control. CONCLUSIONS Our in vitro and in vivo findings provide evidence of a role of SQSTM1 and thereby autophagy in orthodontic tooth movement.
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Affiliation(s)
- S Memmert
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany. .,Section of Experimental Dento-Maxillo-Facial Medicine, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Bonn, Germany.
| | - A V B Nogueira
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - A Damanaki
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - M Nokhbehsaim
- Section of Experimental Dento-Maxillo-Facial Medicine, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Bonn, Germany
| | - B Rath-Deschner
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany
| | - W Götz
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany
| | - L Gölz
- Department of Orthodontics and Orofacial Orthopedics, University of Erlangen, Erlangen, Germany.,Institute of Human Genetics, University Hospital of Bonn, Bonn, Germany
| | - J A Cirelli
- Department of Diagnosis and Surgery, School of Dentistry at Araraquara, University Estadual Paulista-UNESP, Araraquara, Brazil
| | - A Till
- Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn, Bonn, Germany
| | - A Jäger
- Department of Orthodontics, Center of Dento-Maxillo-Facial Medicine, University of Bonn, Welschnonnenstr. 17, 53111, Bonn, Germany
| | - J Deschner
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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10
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Autophagy in Neurotrauma: Good, Bad, or Dysregulated. Cells 2019; 8:cells8070693. [PMID: 31295858 PMCID: PMC6678153 DOI: 10.3390/cells8070693] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/06/2019] [Accepted: 07/09/2019] [Indexed: 12/12/2022] Open
Abstract
Autophagy is a physiological process that helps maintain a balance between the manufacture of cellular components and breakdown of damaged organelles and other toxic cellular constituents. Changes in autophagic markers are readily detectable in the spinal cord and brain following neurotrauma, including traumatic spinal cord and brain injury (SCI/TBI). However, the role of autophagy in neurotrauma remains less clear. Whether autophagy is good or bad is under debate, with strong support for both a beneficial and detrimental role for autophagy in experimental models of neurotrauma. Emerging data suggest that autophagic flux, a measure of autophagic degradation activity, is impaired in injured central nervous systems (CNS), and interventions that stimulate autophagic flux may provide neuroprotection in SCI/TBI models. Recent data demonstrating that neurotrauma can cause lysosomal membrane damage resulting in pathological autophagosome accumulation in the spinal cord and brain further supports the idea that the impairment of the autophagy–lysosome pathway may be a part of secondary injury processes of SCI/TBI. Here, we review experimental work on the complex and varied responses of autophagy in terms of both the beneficial and detrimental effects in SCI and TBI models. We also discuss the existing and developing therapeutic options aimed at reducing the disruption of autophagy to protect the CNS after injuries.
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11
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Civelek M, Flory S, Meloh H, Fitzenberger E, Wenzel U. The polyphenol quercetin protects from glucotoxicity depending on the aggresome in Caenorhabditis elegans. Eur J Nutr 2019; 59:485-491. [PMID: 30706126 DOI: 10.1007/s00394-019-01917-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/25/2019] [Indexed: 10/27/2022]
Abstract
PURPOSE Impaired proteostasis, i.e., protein homeostasis, is considered as a consequence of high-glucose exposure and is associated with reduced survival. The previous studies demonstrated that the polyphenol quercetin can protect from glucotoxicity. The aim of the present study was to unravel the contribution of the aggresome, sequestering potentially cytotoxic aggregates and also acting as a staging center for eventual autophagic clearance from the cell. METHODS Knockdown of the aggresome-relevant genes dnc-1 and ubql-1 was achieved in stress-sensitive mev-1 mutants of the nematode Caenorhabditis elegans by RNA interference (RNAi). Survival assay was conducted under heat stress at 37 °C, protein aggregation using ProteoStat® and chymotrypsin-like proteasomal activity according to the cleavage of a fluorogenic peptide substrate. RESULTS Survival was reduced by knockdown of ubql-1 and even more by knockdown of dnc-1 which both were not further reduced by addition of glucose. The rescue of survival due to quercetin in glucose-exposed nematodes was completely prevented under RNAi versus ubql-1 or dnc-1. Both knockdowns caused an increase of aggregated protein and prevented the reduction of aggregated protein caused by quercetin in glucose-exposed animals. Finally, the knockdown of ubql-1 and dnc-1 blocked the increase of proteasomal activity achieved by quercetin in glucose-treated nematodes. CONCLUSIONS The study provides evidence that quercetin protects C. elegans from glucotoxicity through the activation of the aggresome, thereby, quercetin prevents the aggregation and functional loss of proteins, which is typically caused by enhanced glucose concentrations.
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Affiliation(s)
- Mehtap Civelek
- Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392, Giessen, Germany
| | - Sandra Flory
- Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392, Giessen, Germany
| | - Hedda Meloh
- Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392, Giessen, Germany
| | - Elena Fitzenberger
- Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392, Giessen, Germany
| | - Uwe Wenzel
- Interdisciplinary Research Center, Justus-Liebig-University of Giessen, 35392, Giessen, Germany.
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12
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Muñoz-Galdeano T, Reigada D, Del Águila Á, Velez I, Caballero-López MJ, Maza RM, Nieto-Díaz M. Cell Specific Changes of Autophagy in a Mouse Model of Contusive Spinal Cord Injury. Front Cell Neurosci 2018; 12:164. [PMID: 29946241 PMCID: PMC6005838 DOI: 10.3389/fncel.2018.00164] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 05/28/2018] [Indexed: 12/15/2022] Open
Abstract
Autophagy is an essential process of cellular waist clearance that becomes altered following spinal cord injury (SCI). Details on these changes, including timing after injury, underlying mechanisms, and affected cells, remain controversial. Here we present a characterization of autophagy in the mice spinal cord before and after a contusive SCI. In the undamaged spinal cord, analysis of LC3 and Beclin 1 autophagic markers reveals important differences in basal autophagy between neurons, oligodendrocytes, and astrocytes and even within cell populations. Following moderate contusion, western blot analyses of LC3 indicates that autophagy increases to a maximum at 7 days post injury (dpi), whereas unaltered Beclin 1 expression and increase of p62 suggests a possible blockage of autophagosome clearance. Immunofluorescence analyses of LC3 and Beclin 1 provide additional details that reveal a complex, cell-specific scenario. Autophagy is first activated (1 dpi) in the severed axons, followed by a later (7 dpi) accumulation of phagophores and/or autophagosomes in the neuronal soma without signs of increased initiation. Oligodendrocytes and reactive astrocytes also accumulate phagophores and autophagosomes at 7 dpi, but whereas the accumulation in astrocytes is associated with an increased autophagy initiation, it seems to result from a blockage of the autophagic flux in oligodendrocytes. Comparison with previous studies highlights the complex and heterogeneous autophagic responses induced by the SCI, leading in many cases to contradictory results and interpretations. Future studies should consider this complexity in the design of therapeutic interventions based on the modulation of autophagy to treat SCI.
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Affiliation(s)
- Teresa Muñoz-Galdeano
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
| | - David Reigada
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
| | - Ángela Del Águila
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain.,Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Irene Velez
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
| | - Marcos J Caballero-López
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
| | - Rodrigo M Maza
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
| | - Manuel Nieto-Díaz
- Laboratory of Molecular Neuroprotection, UDI-HNP, Hospital Nacional de Parapléjicos (SESCAM), Toledo, Spain
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13
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Niranjan R, Mishra KP, Thakur AK. Inhibition of Cyclooxygenase-2 (COX-2) Initiates Autophagy and Potentiates MPTP-Induced Autophagic Cell Death of Human Neuroblastoma Cells, SH-SY5Y: an Inside in the Pathology of Parkinson’s Disease. Mol Neurobiol 2018; 55:8038-8050. [DOI: 10.1007/s12035-018-0950-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/05/2018] [Indexed: 01/22/2023]
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14
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Nie J, Chen J, Yang J, Pei Q, Li J, Liu J, Xu L, Li N, Chen Y, Chen X, Luo H, Sun T. Inhibition of mammalian target of rapamycin complex 1 signaling by n-3 polyunsaturated fatty acids promotes locomotor recovery after spinal cord injury. Mol Med Rep 2018; 17:5894-5902. [PMID: 29436695 PMCID: PMC5866035 DOI: 10.3892/mmr.2018.8583] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 01/09/2018] [Indexed: 01/06/2023] Open
Abstract
The present study aimed to explore the effects of n‑3 polyunsaturated fatty acids (PUFAs) on autophagy and their potential for promoting locomotor recovery after spinal cord injury (SCI). Primary neurons were isolated and cultured. Sprague‑Dawley rats were randomly divided into three groups and fed diets with different amounts of n‑3 PUFAs. A model of spinal cord contusion was created at the T10 spinal segment and the composition of PUFAs was analyzed using gas chromatography. Spinal repair and motor function were evaluated postoperatively. Assessment of the effects of n‑3 PUFAs on autophagy and mammalian target of rapamycin complex 1 (mTORC1) was performed using immunofluorescence staining and western blotting. In vitro, n‑3 PUFAs inhibited mTORC1 and enhanced autophagy. The n‑3 PUFA levels and the ratio of n‑3 PUFA to n‑6 PUFA in the spinal cord and serum of rats fed a high‑n‑3 PUFA diet were higher before and after operation (P<0.05). Additionally, rats in the high‑n‑3 PUFA group showed improved motor function recovery, spinal cord repair‑related protein expression level (MBP, Galc and GFAP). Expression levels if these protiens in the high‑n‑3 PUFA diet group expressed the highest levels, followed by the low‑n‑3 PUFA diet group and finally the control group (P<0.05). high‑n‑3 PUFA diet promoted autophagy ability and inhibited activity of the mTORC1 signaling pathway compared with the low‑n‑3 PUFA diet group or the control group (P<0.05). These results suggest that exogenous dietary n‑3 PUFAs can inhibit mTORC1 signaling and enhance autophagy, promoting functional recovery of rats with SCI.
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Affiliation(s)
- Jiping Nie
- Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
| | - Jian Chen
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Jianguo Yang
- Department of Orthopedics, Huhhot First Hospital, Huhhot, Inner Mongolia Autonomous Region 010020, P.R. China
| | - Qinqin Pei
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Jing Li
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Jia Liu
- Department of Orthopedics, Affiliated Hospital of Youjiang Medical College for Nationalities, Baise, Guangxi 533000, P.R. China
| | - Lixin Xu
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Nan Li
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Youhao Chen
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Xiaohua Chen
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Hao Luo
- Department of Orthopedics, Three Gorges Central Hospital of Chongqing, Chongqing 404000, P.R. China
| | - Tiansheng Sun
- Southern Medical University, Guangzhou, Guangdong 510515, P.R. China
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15
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Song HL, Zhang X, Wang WZ, Liu RH, Zhao K, Liu MY, Gong WM, Ning B. Neuroprotective mechanisms of rutin for spinal cord injury through anti-oxidation and anti-inflammation and inhibition of p38 mitogen activated protein kinase pathway. Neural Regen Res 2018; 13:128-134. [PMID: 29451217 PMCID: PMC5840978 DOI: 10.4103/1673-5374.217349] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Rutin has anti-inflammatory, antioxidant, anti-viral, anti-tumor and immune regulatory effects. However, the neuroprotective effects of rutin in spinal cord injury are unknown. The p38 mitogen activated protein kinase (p38 MAPK) pathway is the most important member of the MAPK family that controls inflammation. We assumed that the mechanism of rutin in the repair of spinal cord injury is associated with the inhibition of p38 MAPK pathway. Allen's method was used to establish a rat model of spinal cord injury. The rat model was intraperitoneally injected with rutin (30 mg/kg) for 3 days. After treatment with rutin, Basso, Beattie and Bresnahan locomotor function scores increased. Water content, tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6 levels, p38 MAPK protein expression and caspase-3 and -9 activities in T8–9 spinal cord decreased. Oxidative stress related markers superoxide dismutase and glutathione peroxidase levels increased in peripheral blood. Rutin exerts neuroprotective effect through anti-oxidation, anti-inflammation, anti-apoptosis and inhibition of p38 MAPK pathway.
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Affiliation(s)
- Hong-Liang Song
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Xiang Zhang
- Hospital Pharmacy, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Wen-Zhao Wang
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Rong-Han Liu
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Kai Zhao
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Ming-Yuan Liu
- Department of Gynecology and Obstetrics, Jinan Maternity and Child Care Hospital, Jinan, Shandong Province, China
| | - Wei-Ming Gong
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
| | - Bin Ning
- Department of Spinal Surgery, Jinan Central Hospital Affiliated to Shandong University, Jinan, Shandong Province, China
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16
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Lipinski MM, Wu J, Faden AI, Sarkar C. Function and Mechanisms of Autophagy in Brain and Spinal Cord Trauma. Antioxid Redox Signal 2015; 23:565-77. [PMID: 25808205 PMCID: PMC4545370 DOI: 10.1089/ars.2015.6306] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
SIGNIFICANCE Traumatic brain injury (TBI) and spinal cord injury (SCI) are major causes of death and long-term disability worldwide. Despite important pathophysiological differences between these disorders, in many respects, mechanisms of injury are similar. During both TBI and SCI, some cells are directly mechanically injured, but more die as a result of injury-induced biochemical changes (secondary injury). Autophagy, a lysosome-dependent cellular degradation pathway with neuroprotective properties, has been implicated both clinically and experimentally in the delayed response to TBI and SCI. However, until recently, its mechanisms and function remained unknown, reflecting in part the difficulty of isolating autophagic processes from ongoing cell death and other cellular events. RECENT ADVANCES Emerging data suggest that depending on the location and severity of traumatic injury, autophagy flux--defined as the progress of cargo through the autophagy system and leading to its degradation--may be either increased or decreased after central nervous system trauma. CRITICAL ISSUES While increased autophagy flux may be protective after mild injury, after more severe trauma inhibition of autophagy flux may contribute to neuronal cell death, indicating disruption of autophagy as a part of the secondary injury mechanism. FUTURE DIRECTIONS Augmentation and/or restoration of autophagy flux may provide a potential therapeutic target for treatment of TBI and SCI. Development of those treatments will require thorough characterization of changes in autophagy flux, its mechanisms and function over time after injury.
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Affiliation(s)
- Marta M Lipinski
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine , Baltimore, Maryland
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine , Baltimore, Maryland
| | - Alan I Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine , Baltimore, Maryland
| | - Chinmoy Sarkar
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine , Baltimore, Maryland
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17
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Yuntao F, Chenjia G, Panpan Z, Wenjun Z, Suhua W, Guangwei X, Haifeng S, Jian L, Wanxin P, Yun F, Cai J, Aschner M, Rongzhu L. Role of autophagy in methylmercury-induced neurotoxicity in rat primary astrocytes. Arch Toxicol 2014; 90:333-45. [PMID: 25488884 DOI: 10.1007/s00204-014-1425-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 11/25/2014] [Indexed: 11/30/2022]
Abstract
Autophagy is an evolutionarily conserved process in which cytoplasmic proteins and organelles are degraded and recycled for reuse. There are numerous reports on the role of autophagy in cell growth and death; however, the role of autophagy in methylmercury (MeHg)-induced neurotoxicity has yet to be identified. We studied the role of autophagy in MeHg-induced neurotoxicity in astrocytes. MeHg reduced astrocytic viability in a concentration- and time-dependent manner, and induced apoptosis. Pharmacological inhibition of autophagy with 3-methyladenine or chloroquine, as well as the silencing of the autophagy-related protein 5, increased MeHg-induced cytotoxicity and the ratio of apoptotic astrocytes. Conversely, rapamycin, an autophagy inducer, along with as N-acetyl-L-cysteine, a precursor of reduced glutathione, decreased MeHg-induced toxicity and the ratio of apoptotic astrocytes. These results indicated that MeHg-induced neurotoxicity was reduced, at least in part, through the activation of autophagy. Accordingly, modulation of autophagy may offer a new avenue for attenuating MeHg-induced neurotoxicity.
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Affiliation(s)
- Fang Yuntao
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Guo Chenjia
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Zhang Panpan
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Zhao Wenjun
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Wang Suhua
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Xing Guangwei
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Shi Haifeng
- Institute of Life Sciences, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Lu Jian
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Peng Wanxin
- Department of Biology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Feng Yun
- Department of Pharmacology, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China
| | - Jiyang Cai
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, TX, 77550-1106, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Lu Rongzhu
- Department of Public Health Laboratory Sciences, School of Medicine, Jiangsu University, Zhenjiang, 212013, Jiangsu, China.
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18
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Ge J, Li L, Jin Q, Liu YC, Zhao L, Song HH. Functional IRGM polymorphism is associated with language impairment in glioma and upregulates cytokine expressions. Tumour Biol 2014; 35:8343-8. [PMID: 24859836 DOI: 10.1007/s13277-014-2091-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 05/12/2014] [Indexed: 11/30/2022] Open
Abstract
Immunity-related GTPase family M protein (IRGM) is a human protein recently highlighted for its contribution to autophagy upon infections. Evidences have shown that IRGM may also play critical roles in the pathogenesis of cancer. However, correlation between IRGM and glioma remains unclear. In the current study, we investigated two IRGM genetic polymorphisms, rs10065172C/T and rs13361189T/C, in glioma and their effects on cytokine expression. Data showed that prevalences of rs13361189TC genotype were significantly increased in glioma patients than in healthy controls (odds ratio (OR) = 1.53, 95 % confidence interval (CI) 1.05-2.24, P = 0.028), and frequency of polymorphic rs13361189CC genotype was further elevated (OR = 2.43, 95 % CI 1.43-4.14, P = 0.001). Interestingly, rs13361189TC and CC genotypes revealed a strong association with language impairment in glioma patients (OR = 2.16, P = 0.023; OR = 3.71, P = 0.001, respectively). When analyzing these two polymorphisms with related cytokine expression, we observed that subjects carrying rs13361189CC genotype had higher serum level of interferon-gamma (IFN-γ) than those with wild-type TT genotype (P < 0.01). In addition, subjects with rs13361189TC and CC genotypes presented elevated serum level of interleukin 4 (IL-4) than those with TT genotype. These data indicate a potential role of IRGM in the development of glioma probably by affecting IFN-γ and IL-4.
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Affiliation(s)
- Jing Ge
- College of Humanities and Law, North China University of Technology, Beijing, 100144, China
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