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Andrusaite A, Lewis J, Frede A, Farthing A, Kästele V, Montgomery J, Mowat A, Mann E, Milling S. Microbiota-derived butyrate inhibits cDC development via HDAC inhibition, diminishing their ability to prime T cells. Mucosal Immunol 2024:S1933-0219(24)00084-9. [PMID: 39142634 DOI: 10.1016/j.mucimm.2024.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/12/2024] [Accepted: 08/07/2024] [Indexed: 08/16/2024]
Abstract
Conventional dendritic cells (cDC) are central to maintaining the balance between protective immune responses and tolerance to harmless antigens, especially in the intestine. Short chain fatty acids (SCFAs) such as butyrate play critical roles in regulating intestinal immunity, but the underlying mechanisms remain unclear. Here we demonstrate that microbiota-derived butyrate alters intestinal cDC populations in vivo resulting in decreased numbers of the cDC2 lineage. By establishing a novel in vitro culture model, we show that butyrate has a direct and selective ability to repress the development of cDC2 from cDC precursors, an effect that is independent of G-protein coupled receptors (GPCRs) and is due to inhibition of histone deacetylase 3. Finally, cDC derived from pre-cDC in the presence of butyrate in vitro express lower levels of costimulatory molecules and have a decreased ability to prime naïve T cells. Together, our data show that butyrate affects the developmental trajectory of cDC, selectively repressing the cDC2 lineage and reducing their ability to stimulate T cells. These properties may help explain the ability of butyrate to maintain homeostasis in the intestine.
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Affiliation(s)
- Anna Andrusaite
- School of Infection and Immunity, University of Glasgow, UK.
| | - Jennifer Lewis
- School of Infection and Immunity, University of Glasgow, UK
| | - Annika Frede
- School of Infection and Immunity, University of Glasgow, UK
| | | | - Verena Kästele
- School of Infection and Immunity, University of Glasgow, UK
| | | | - Allan Mowat
- School of Infection and Immunity, University of Glasgow, UK
| | - Elizabeth Mann
- Lydia Becker Institute of Immunology and Inflammation, University of Manchester, UK
| | - Simon Milling
- School of Infection and Immunity, University of Glasgow, UK.
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2
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Zhang Q, Xue J, Tang J, Wu S, Liu Z, Wu C, Liu C, Liu Y, Lin J, Han J, Liu L, Chen Y, Yang J, Li Z, Zhao L, Wei Y, Li Y, Zhuo Y. Modulating amacrine cell-derived dopamine signaling promotes optic nerve regeneration and preserves visual function. SCIENCE ADVANCES 2024; 10:eado0866. [PMID: 39093964 PMCID: PMC11296332 DOI: 10.1126/sciadv.ado0866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 06/27/2024] [Indexed: 08/04/2024]
Abstract
As part of the central nervous system, the optic nerve, composed of axons from retinal ganglion cells (RGCs), generally fails to regenerate on its own when injured in adult mammals. An innovative approach to promoting optic nerve regeneration involves manipulating the interactions between amacrine cells (ACs) and RGCs. Here, we identified a unique AC subtype, dopaminergic ACs (DACs), that responded early after optic nerve crush by down-regulating neuronal activity and reducing retinal dopamine (DA) release. Activating DACs or augmenting DA release with levodopa demonstrated neuroprotective effects and modestly enhanced axon regeneration. Within this context, we pinpointed the DA receptor D1 (DRD1) as a critical mediator of DAC-derived DA and showed that RGC-specific Drd1 overexpression effectively overcame subtype-specific barriers to regeneration. This strategy markedly boosted RGC survival and axon regeneration after crush and preserved vision in a glaucoma model. This study unveils the crucial role of DAC-derived DA signaling in optic nerve regeneration, holding promise for therapeutic insights into neural repair.
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Affiliation(s)
- Qi Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Jingfei Xue
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Jiahui Tang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Siting Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhe Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Caiqing Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Canying Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Yidan Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Jicheng Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Jiaxu Han
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Liyan Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Yuze Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Jinpeng Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhidong Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Ling Zhao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Yantao Wei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Sun Yat-sen University, Guangzhou 510060, China
| | - Yiqing Li
- Corresponding author. (Y. Li); (Y.Z.); (Y.W.)
| | - Yehong Zhuo
- Corresponding author. (Y. Li); (Y.Z.); (Y.W.)
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3
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Kibalnyk Y, Afanasiev E, Noble RMN, Watson AES, Poverennaya I, Dittmann NL, Alexiou M, Goodkey K, Greenwell AA, Ussher JR, Adameyko I, Massey J, Graf D, Bourque SL, Stratton JA, Voronova A. The chromatin regulator Ankrd11 controls cardiac neural crest cell-mediated outflow tract remodeling and heart function. Nat Commun 2024; 15:4632. [PMID: 38951500 PMCID: PMC11217281 DOI: 10.1038/s41467-024-48955-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 05/17/2024] [Indexed: 07/03/2024] Open
Abstract
ANKRD11 (Ankyrin Repeat Domain 11) is a chromatin regulator and a causative gene for KBG syndrome, a rare developmental disorder characterized by multiple organ abnormalities, including cardiac defects. However, the role of ANKRD11 in heart development is unknown. The neural crest plays a leading role in embryonic heart development, and its dysfunction is implicated in congenital heart defects. We demonstrate that conditional knockout of Ankrd11 in the murine embryonic neural crest results in persistent truncus arteriosus, ventricular dilation, and impaired ventricular contractility. We further show these defects occur due to aberrant cardiac neural crest cell organization leading to outflow tract septation failure. Lastly, knockout of Ankrd11 in the neural crest leads to impaired expression of various transcription factors, chromatin remodelers and signaling pathways, including mTOR, BMP and TGF-β in the cardiac neural crest cells. In this work, we identify Ankrd11 as a regulator of neural crest-mediated heart development and function.
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Affiliation(s)
- Yana Kibalnyk
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
| | - Elia Afanasiev
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Ronan M N Noble
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
- Department of Pediatrics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2G3, Canada
| | - Adrianne E S Watson
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
| | - Irina Poverennaya
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, 1090, Vienna, Austria
| | - Nicole L Dittmann
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
- Neuroscience and Mental Health Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Maria Alexiou
- Department of Dentistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Kara Goodkey
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
| | - Amanda A Greenwell
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
- Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Edmonton, AB, T6G 2H1, Canada
| | - John R Ussher
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
- Faculty of Pharmacy & Pharmaceutical Sciences, University of Alberta, Edmonton, Alberta, Edmonton, AB, T6G 2H1, Canada
| | - Igor Adameyko
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, 1090, Vienna, Austria
- Department of Physiology and Pharmacology, Karolinska Institutet, 17177, Stockholm, Sweden
| | | | - Daniel Graf
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
- Department of Dentistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada
| | - Stephane L Bourque
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada
- Department of Anesthesiology & Pain Medicine, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2G3, Canada
| | - Jo Anne Stratton
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Anastassia Voronova
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
- Women and Children's Health Research Institute, 5-083 Edmonton Clinic Health Academy, University of Alberta, 11405 87 Avenue NW, Edmonton, AB, T6G 1C9, Canada.
- Neuroscience and Mental Health Institute, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2E1, Canada.
- Department of Cell Biology, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
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4
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Shan F, Zhang N, Yao X, Li Y, Wang Z, Zhang C, Wang Y. Mechanosensitive channel of large conductance enhances the mechanical stretching-induced upregulation of glycolysis and oxidative metabolism in Schwann cells. Cell Commun Signal 2024; 22:93. [PMID: 38302971 PMCID: PMC10835878 DOI: 10.1186/s12964-024-01497-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 01/21/2024] [Indexed: 02/03/2024] Open
Abstract
BACKGROUND Physical exercise directly stretching the peripheral nerve promotes nerve regeneration; however, its action mechanism remains elusive. Our present study aimed to investigate the effects of mechanosensitive channel of large conductance (MscL) activated by mechanical stretching on the cultured Schwann cells (SCs) and explore the possible mechanism. METHODS Primary SCs from neonatal mice at 3-5 days of age were derived and transfected with the lentivirus vector expressing a mutant version of MscL, MscL-G22S. We first detected the cell viability and calcium ion (Ca2+) influx in the MscL-G22S-expressing SCs with low-intensity mechanical stretching and the controls. Proteomic and energy metabolomics analyses were performed to investigate the comprehensive effects of MscL-G22S activation on SCs. Measurement of glycolysis- and oxidative phosphorylation-related molecules and ATP production were respectively performed to further validate the effects of MscL-G22S activation on SCs. Finally, the roles of phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway in the mechanism of energy metabolism modulation of SCs by MscL-G22S activation was investigated. RESULTS Mechanical stretching-induced MscL-G22S activation significantly increased the cell viability and Ca2+ influx into the SCs. Both the proteomic and targeted energy metabolomics analysis indicated the upregulation of energy metabolism as the main action mechanism of MscL-G22S-activation on SCs. MscL-G22S-activated SCs showed significant upregulation of glycolysis and oxidative phosphorylation when SCs with stretching alone had only mild upregulation of energy metabolism than those without stimuli. MscL-G22S activation caused significant phosphorylation of the PI3K/AKT/mTOR signaling pathway and upregulation of HIF-1α/c-Myc. Inhibition of PI3K abolished the MscL-G22S activation-induced upregulation of HIF-1α/c-Myc signaling in SCs and reduced the levels of glycolysis- and oxidative phosphorylation-related substrates and mitochondrial activity. CONCLUSION Mechanical stretching activates MscL-G22S to significantly promote the energy metabolism of SCs and the production of energic substrates, which may be applied to enhance nerve regeneration via the glia-axonal metabolic coupling.
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Affiliation(s)
- Fangzhen Shan
- Medical Research Centre, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China
| | - Nannan Zhang
- Department of Respiratory and Critical Care, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China
| | - Xiaoying Yao
- Medical Research Centre, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China
| | - Yi Li
- Department of Neurology, Affiliated Hospital of Jining Medical University, 89 Guhuai Road, Jining City, Shandong Province, 272029, China
| | - Zihao Wang
- Cheeloo Medical College, Shandong University, Jinan, Shandong Province, China
| | - Chuanji Zhang
- College of Rehabilitation Medicine, Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, China
| | - Yuzhong Wang
- Medical Research Centre, Affiliated Hospital of Jining Medical University, Jining, Shandong Province, China.
- Department of Neurology, Affiliated Hospital of Jining Medical University, 89 Guhuai Road, Jining City, Shandong Province, 272029, China.
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5
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Yoo A, Kim JI, Lee H, Nirmala FS, Hahm JH, Seo HD, Jung CH, Ha TY, Ahn J. Gromwell ameliorates glucocorticoid-induced muscle atrophy through the regulation of Akt/mTOR pathway. Chin Med 2024; 19:20. [PMID: 38287373 PMCID: PMC10826094 DOI: 10.1186/s13020-024-00890-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 01/18/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Muscle atrophy is characterized by decreased muscle mass, function, and strength. Synthetic glucocorticoids, including dexamethasone (Dexa), are commonly used to treat autoimmune diseases. However, prolonged exposure of Dexa with high dose exerts severe side effects, including muscle atrophy. The purpose of this study was to investigate whether Gromwell root extract (GW) can prevent Dexa-induced muscle atrophy in C2C12 cells and mice and to characterize the composition of GW to identify bioactive compounds. METHODS For in vitro experiments, GW (0.5 and 1 µg/mL) or lithospermic acid (LA, 5 and 10 µM) was added to C2C12 myotubes on day 4 of differentiation and incubated for 24 h, along with 50 µM Dexa. For in vivo experiment, four-week-old male C57BL/6 mice were randomly divided into the four following groups (n = 7/group): Con group, Dexa group, GW0.1 group, and GW0.2 group. Mice were fed experimental diets of AIN-93 M with or without 0.1 or 0.2% GW for 4 weeks. Subsequently, muscle atrophy was induced by administering an intraperitoneal injection of Dexa at a dose of 15 mg/kg/day for 38 days, in conjunction with dietary intake. RESULTS In Dexa-induced myotube atrophy, treatment with GW increased myotube diameter, reduced the expression of muscle atrophy markers, and enhanced the expression of myosin heavy chain (MHC) isoforms in C2C12 cells. Supplementation with the GW improved muscle function and performance in mice with Dexa-induced muscle atrophy, evidenced in the grip strength and running tests. The GW group showed increased lean body mass, skeletal muscle mass, size, and myosin heavy chain isoform expression, along with reduced skeletal muscle atrophy markers in Dexa-injected mice. Supplementation with GW increased protein synthesis and decreased protein degradation through the Akt/mammalian target of rapamycin and glucocorticoid receptor/forkhead box O3 signaling pathways, respectively. We identified LA as a potential bioactive component of the GW. LA treatment increased myotube diameter and decreased the expression of muscle atrophy markers in Dexa-induced C2C12 cells. CONCLUSIONS These findings underscore the potential of the GW in preventing Dexa-induced skeletal muscle atrophy and highlight the contribution of LA to its effects.
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Affiliation(s)
- Ahyoung Yoo
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
| | - Jung-In Kim
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
- Division of Food Biotechnology, University of Science and Technology, Daejeon, 34113, Korea
| | - Hyunjung Lee
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
| | - Farida S Nirmala
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
- Division of Food Biotechnology, University of Science and Technology, Daejeon, 34113, Korea
| | - Jeong-Hoon Hahm
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
| | - Hyo Deok Seo
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
| | - Chang Hwa Jung
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
- Division of Food Biotechnology, University of Science and Technology, Daejeon, 34113, Korea
| | - Tae Youl Ha
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea
- Division of Food Biotechnology, University of Science and Technology, Daejeon, 34113, Korea
| | - Jiyun Ahn
- Aging and Metabolism Research Group, Korea Food Research Institute, Wanju-gun, 55365, Korea.
- Division of Food Biotechnology, University of Science and Technology, Daejeon, 34113, Korea.
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6
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Zhou K, Wei W, Yang D, Zhang H, Yang W, Zhang Y, Nie Y, Hao M, Wang P, Ruan H, Zhang T, Wang S, Liu Y. Dual electrical stimulation at spinal-muscular interface reconstructs spinal sensorimotor circuits after spinal cord injury. Nat Commun 2024; 15:619. [PMID: 38242904 PMCID: PMC10799086 DOI: 10.1038/s41467-024-44898-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 01/09/2024] [Indexed: 01/21/2024] Open
Abstract
The neural signals produced by varying electrical stimulation parameters lead to characteristic neural circuit responses. However, the characteristics of neural circuits reconstructed by electrical signals remain poorly understood, which greatly limits the application of such electrical neuromodulation techniques for the treatment of spinal cord injury. Here, we develop a dual electrical stimulation system that combines epidural electrical and muscle stimulation to mimic feedforward and feedback electrical signals in spinal sensorimotor circuits. We demonstrate that a stimulus frequency of 10-20 Hz under dual stimulation conditions is required for structural and functional reconstruction of spinal sensorimotor circuits, which not only activates genes associated with axonal regeneration of motoneurons, but also improves the excitability of spinal neurons. Overall, the results provide insights into neural signal decoding during spinal sensorimotor circuit reconstruction, suggesting that the combination of epidural electrical and muscle stimulation is a promising method for the treatment of spinal cord injury.
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Affiliation(s)
- Kai Zhou
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China
| | - Wei Wei
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China
| | - Dan Yang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China
- Department of Anatomy, School of Basic Medical Science, Guizhou Medical University, Guiyang, 550025, China
| | - Hui Zhang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China
| | - Wei Yang
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China
| | - Yunpeng Zhang
- Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, Suzhou, Jiangsu, 215163, China
| | - Yingnan Nie
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, China
| | - Mingming Hao
- i-Lab, Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China
- Ningbo Medical Centre Lihuili Hospital, Ningbo, Zhejiang, 315048, China
| | - Pengcheng Wang
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Hang Ruan
- Institutes of Biology and Medical Sciences, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Ting Zhang
- i-Lab, Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-tech and Nano-bionics, Chinese Academy of Sciences, Suzhou, Jiangsu, 215123, China
| | - Shouyan Wang
- Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, China
| | - Yaobo Liu
- Jiangsu Key Laboratory of Neuropsychiatric Diseases and Institute of Neuroscience, Soochow University; Clinical Research Center of Neurological Disease, The Second Affiliated Hospital of Soochow University, Suzhou, 215123, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
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7
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Park SB, Lim B, Kim KY, Koh B. Long and Short-Term Effect of mTOR Regulation on Cerebral Organoid Growth and Differentiations. Tissue Eng Regen Med 2024; 21:159-169. [PMID: 38153672 PMCID: PMC10764682 DOI: 10.1007/s13770-023-00611-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 09/20/2023] [Accepted: 10/29/2023] [Indexed: 12/29/2023] Open
Abstract
BACKGROUND The mammalian target of rapamycin (mTOR) signaling is critical for the maintenance and differentiation of neurogenesis, and conceivably for many other brain developmental processes. However, in vivo studies of mTOR functions in the brain are often hampered due to the essential role of the associated signaling in brain development. METHODS We monitored the long- and short-term effects of mTOR signaling regulation on cerebral organoids growth, differentiation and function using an mTOR inhibitor (everolimus) and an mTOR activator (MHY1485). RESULTS Short-term treatment with MHY1485 induced faster organoid growth and differentiation, while long-term treatment induced the maturation of cerebral organoids. CONCLUSION These data suggest that the optimal activity of mTOR is crucial in maintaining normal brain development, and its role is not confined to the early neurogenic phase of brain development.
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Affiliation(s)
- Sung Bum Park
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea
| | - Byungho Lim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea
| | - Ki Young Kim
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea.
| | - Byumseok Koh
- Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology, 141 Gajeong-ro, Yuseong-gu, Daejeon, 34114, Republic of Korea.
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8
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Hu J, Zhang G, Rodemer W, Jin LQ, Selzer ME. Combined RhoA morpholino and ChABC treatment protects identified lamprey neurons from retrograde apoptosis after spinal cord injury. Front Cell Neurosci 2023; 17:1292012. [PMID: 38179205 PMCID: PMC10764559 DOI: 10.3389/fncel.2023.1292012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024] Open
Abstract
Previously, we reported that RhoA knockdown by morpholino antisense oligonucleotides (MOs), and enzymatic digestion of chondroitin sulfate proteoglycans (CSPGs) at the site of injury with chondroitinase ABC (ChABC), each can reduce retrograde neuronal apoptosis after spinal cord transection in the lamprey. To elucidate the mechanisms in neuronal survival and axon regeneration, we have investigated whether these two effects are additive in vivo. We used lampreys as a spinal cord injury model. MOs were used to knockdown RhoA and Chondroitinase ABC (ChABC) was used to digest CSPGs in vivo. Retrograde labeling, fluorochrome-labeled inhibitor of caspase activity (FLICA), immunohistochemistry, and western blots were performed to assess axonal regeneration, neuronal apoptotic signaling and Akt activation. Four treatment combinations were evaluated at 2-, 4-, and 10-weeks post-transection: (1) Control MO plus enzyme buffer (Ctrl); (2) control MO plus ChABC; (3) RhoA MO plus enzyme buffer (RhoA MO); and (4) RhoA MO plus ChABC (RhoA MO + ChABC). Consistent with our previous findings, at 4-weeks post-transection, there was less caspase activation in the ChABC and RhoA MO groups than in the Ctrl group. Moreover, the RhoA MO plus ChABC group had the best protective effect on identified reticulospinal (RS) neurons among the four treatment combinations. At 2 weeks post-transection, when axons have retracted maximally in the rostral stump and are beginning to regenerate back toward the lesion, the axon tips in the three treatment groups each were closer to the transection than those in the Ctr MO plus enzyme buffer group. Long-term axon regeneration also was evaluated for the large, individually identified RS neurons at 10 weeks post-transection by retrograde labeling. The percent regenerated axons in the RhoA MO plus ChABC group was greater than that in any of the other groups. Akt phosphorylation levels at threonine 308 was quantified in the identified RS neurons by western blots and immunofluorescence. The RhoA MO plus ChABC treatment enhanced pAkt-308 phosphorylation more than any of the other treatment groups. Although some of the effects of CSPGs are mediated through RhoA activation, some growth-inhibiting mechanisms of RhoA and CSPGs are independent of each other, so combinatorial therapies may be warranted.
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Affiliation(s)
- Jianli Hu
- Center for Neural Repair and Rehabilitation (Shriners Hospitals Pediatric Research Center), Lewis Katz School of Medicine (LKSOM) at Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, LKSOM, Philadelphia, PA, United States
| | - Guixin Zhang
- Center for Neural Repair and Rehabilitation (Shriners Hospitals Pediatric Research Center), Lewis Katz School of Medicine (LKSOM) at Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, LKSOM, Philadelphia, PA, United States
| | - William Rodemer
- Center for Neurodegenerative Disease Research, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Li-Qing Jin
- Center for Neural Repair and Rehabilitation (Shriners Hospitals Pediatric Research Center), Lewis Katz School of Medicine (LKSOM) at Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, LKSOM, Philadelphia, PA, United States
| | - Michael E. Selzer
- Center for Neural Repair and Rehabilitation (Shriners Hospitals Pediatric Research Center), Lewis Katz School of Medicine (LKSOM) at Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, LKSOM, Philadelphia, PA, United States
- Department of Neurology, LKSOM, Philadelphia, PA, United States
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9
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Jiang J, Zhang L, Zou J, Liu J, Yang J, Jiang Q, Duan P, Jiang B. Phosphorylated S6K1 and 4E-BP1 play different roles in constitutively active Rheb-mediated retinal ganglion cell survival and axon regeneration after optic nerve injury. Neural Regen Res 2023; 18:2526-2534. [PMID: 37282486 PMCID: PMC10360084 DOI: 10.4103/1673-5374.371372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Abstract
Ras homolog enriched in brain (Rheb) is a small GTPase that activates mammalian target of rapamycin complex 1 (mTORC1). Previous studies have shown that constitutively active Rheb can enhance the regeneration of sensory axons after spinal cord injury by activating downstream effectors of mTOR. S6K1 and 4E-BP1 are important downstream effectors of mTORC1. In this study, we investigated the role of Rheb/mTOR and its downstream effectors S6K1 and 4E-BP1 in the protection of retinal ganglion cells. We transfected an optic nerve crush mouse model with adeno-associated viral 2-mediated constitutively active Rheb and observed the effects on retinal ganglion cell survival and axon regeneration. We found that overexpression of constitutively active Rheb promoted survival of retinal ganglion cells in the acute (14 days) and chronic (21 and 42 days) stages of injury. We also found that either co-expression of the dominant-negative S6K1 mutant or the constitutively active 4E-BP1 mutant together with constitutively active Rheb markedly inhibited axon regeneration of retinal ganglion cells. This suggests that mTORC1-mediated S6K1 activation and 4E-BP1 inhibition were necessary components for constitutively active Rheb-induced axon regeneration. However, only S6K1 activation, but not 4E-BP1 knockdown, induced axon regeneration when applied alone. Furthermore, S6K1 activation promoted the survival of retinal ganglion cells at 14 days post-injury, whereas 4E-BP1 knockdown unexpectedly slightly decreased the survival of retinal ganglion cells at 14 days post-injury. Overexpression of constitutively active 4E-BP1 increased the survival of retinal ganglion cells at 14 days post-injury. Likewise, co-expressing constitutively active Rheb and constitutively active 4E-BP1 markedly increased the survival of retinal ganglion cells compared with overexpression of constitutively active Rheb alone at 14 days post-injury. These findings indicate that functional 4E-BP1 and S6K1 are neuroprotective and that 4E-BP1 may exert protective effects through a pathway at least partially independent of Rheb/mTOR. Together, our results show that constitutively active Rheb promotes the survival of retinal ganglion cells and axon regeneration through modulating S6K1 and 4E-BP1 activity. Phosphorylated S6K1 and 4E-BP1 promote axon regeneration but play an antagonistic role in the survival of retinal ganglion cells.
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Affiliation(s)
- Jikuan Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Lusi Zhang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jingling Zou
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jingyuan Liu
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jia Yang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Qian Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Peiyun Duan
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Bing Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
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10
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Fang F, Liu P, Huang H, Feng X, Li L, Sun Y, Kaufman RJ, Hu Y. RGC-specific ATF4 and/or CHOP deletion rescues glaucomatous neurodegeneration and visual function. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 33:286-295. [PMID: 37547290 PMCID: PMC10400881 DOI: 10.1016/j.omtn.2023.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023]
Abstract
Endoplasmic reticulum (ER) stress has been linked with various acute and chronic neurodegenerative diseases. We previously found that optic nerve (ON) injury and diseases induce neuronal ER stress in retinal ganglion cells (RGCs). We further demonstrated that germline deletion of CHOP preserves the structure and function of both RGC somata and axons in mouse glaucoma models. Here we report that RGC-specific deletion of CHOP and/or its upstream regulator ATF4 synergistically promotes RGC and ON survival and preserves visual function in mouse ON crush and silicone oil-induced ocular hypertension (SOHU) glaucoma models. Consistently, topical application of the ATF4/CHOP chemical inhibitor ISRIB or RGC-specific CRISPR-mediated knockdown of the ATF4 downstream effector Gadd45a also delivers significant neuroprotection in the SOHU glaucoma model. These studies suggest that blocking the neuronal intrinsic ATF4/CHOP axis of ER stress is a promising neuroprotection strategy for neurodegeneration.
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Affiliation(s)
- Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Randal J. Kaufman
- Degenerative Diseases Program, Center for Genetic Disorders and Aging Research, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA 92037, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
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11
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Sah DK, Arjunan A, Lee B, Jung YD. Reactive Oxygen Species and H. pylori Infection: A Comprehensive Review of Their Roles in Gastric Cancer Development. Antioxidants (Basel) 2023; 12:1712. [PMID: 37760015 PMCID: PMC10525271 DOI: 10.3390/antiox12091712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/14/2023] [Accepted: 08/30/2023] [Indexed: 09/29/2023] Open
Abstract
Gastric cancer (GC) is the fifth most common cancer worldwide and makes up a significant component of the global cancer burden. Helicobacter pylori (H. pylori) is the most influential risk factor for GC, with the International Agency for Research on Cancer classifying it as a Class I carcinogen for GC. H. pylori has been shown to persist in stomach acid for decades, causing damage to the stomach's mucosal lining, altering gastric hormone release patterns, and potentially altering gastric function. Epidemiological studies have shown that eliminating H. pylori reduces metachronous cancer. Evidence shows that various molecular alterations are present in gastric cancer and precancerous lesions associated with an H. pylori infection. However, although H. pylori can cause oxidative stress-induced gastric cancer, with antioxidants potentially being a treatment for GC, the exact mechanism underlying GC etiology is not fully understood. This review provides an overview of recent research exploring the pathophysiology of H. pylori-induced oxidative stress that can cause cancer and the antioxidant supplements that can reduce or even eliminate GC occurrence.
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Affiliation(s)
| | | | - Bora Lee
- Department of Biochemistry, Chonnam National University Medical School, Seoyang Ro 264, Jeonnam, Hwasun 58128, Republic of Korea; (D.K.S.); (A.A.)
| | - Young Do Jung
- Department of Biochemistry, Chonnam National University Medical School, Seoyang Ro 264, Jeonnam, Hwasun 58128, Republic of Korea; (D.K.S.); (A.A.)
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12
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Tang X, Balachandran RC, Aschner M, Bowman AB. IGF/mTORC1/S6 Signaling Is Potentiated and Prolonged by Acute Loading of Subtoxicological Manganese Ion. Biomolecules 2023; 13:1229. [PMID: 37627294 PMCID: PMC10452562 DOI: 10.3390/biom13081229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Revised: 08/01/2023] [Accepted: 08/04/2023] [Indexed: 08/27/2023] Open
Abstract
The insulin-like growth factor (IGF)/insulin signaling (IIS) pathway is involved in cellular responses against intracellular divalent manganese ion (Mn2+) accumulation. As a pathway where multiple nodes utilize Mn2+ as a metallic co-factor, how the IIS signaling patterns are affected by Mn2+ overload is unresolved. In our prior studies, acute Mn2+ exposure potentiated IIS kinase activity upon physiological-level stimulation, indicated by elevated phosphorylation of protein kinase B (PKB, also known as AKT). AKT phosphorylation is associated with IIS activity; and provides direct signaling transduction input for the mammalian target of rapamycin complex 1 (mTORC1) and its downstream target ribosomal protein S6 (S6). Here, to better define the impact of Mn2+ exposure on IIS function, Mn2+-induced IIS activation was evaluated with serial concentrations and temporal endpoints. In the wild-type murine striatal neuronal line STHdh, the acute treatment of Mn2+ with IGF induced a Mn2+ concentration-sensitive phosphorylation of S6 at Ser235/236 to as low as 5 μM extracellular Mn2+. This effect required both the essential amino acids and insulin receptor (IR)/IGF receptor (IGFR) signaling input. Similar to simultaneous stimulation of Mn2+ and IGF, when a steady-state elevation of Mn2+ was established via a 24-h pre-exposure, phosphorylation of S6 also displayed higher sensitivity to sub-cytotoxic Mn2+ when compared to AKT phosphorylation at Ser473. This indicates a synergistic effect of sub-cytotoxic Mn2+ on IIS and mTORC1 signaling. Furthermore, elevated intracellular Mn2+, with both durations, led to a prolonged activation in AKT and S6 upon stimulation. Our data demonstrate that the downstream regulator S6 is a highly sensitive target of elevated Mn2+ and is well below the established acute cytotoxicity thresholds (<50 μM). These findings indicate that the IIS/mTORC1 pathways, in which Mn2+ normally serves as an essential co-factor, are dually responsible for the cellular changes in exposures to real-world Mn2+ concentrations.
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Affiliation(s)
- Xueqi Tang
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
| | - Rekha C. Balachandran
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
- Exponent Inc., Alexandria, VA 22314, USA
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Aaron B. Bowman
- School of Health Sciences, Purdue University, West Lafayette, IN 47907, USA; (X.T.)
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13
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Oh BC. Phosphoinositides and intracellular calcium signaling: novel insights into phosphoinositides and calcium coupling as negative regulators of cellular signaling. Exp Mol Med 2023; 55:1702-1712. [PMID: 37524877 PMCID: PMC10474053 DOI: 10.1038/s12276-023-01067-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 08/02/2023] Open
Abstract
Intracellular calcium (Ca2+) and phosphoinositides (PIPs) are crucial for regulating cellular activities such as metabolism and cell survival. Cells maintain precise intracellular Ca2+ and PIP levels via the actions of a complex system of Ca2+ channels, transporters, Ca2+ ATPases, and signaling effectors, including specific lipid kinases, phosphatases, and phospholipases. Recent research has shed light on the complex interplay between Ca2+ and PIP signaling, suggesting that elevated intracellular Ca2+ levels negatively regulate PIP signaling by inhibiting the membrane localization of PIP-binding proteins carrying specific domains, such as the pleckstrin homology (PH) and Ca2+-independent C2 domains. This dysregulation is often associated with cancer and metabolic diseases. PIPs recruit various proteins with PH domains to the plasma membrane in response to growth hormones, which activate signaling pathways regulating metabolism, cell survival, and growth. However, abnormal PIP signaling in cancer cells triggers consistent membrane localization and activation of PIP-binding proteins. In the context of obesity, an excessive intracellular Ca2+ level prevents the membrane localization of the PIP-binding proteins AKT, IRS1, and PLCδ via Ca2+-PIPs, contributing to insulin resistance and other metabolic diseases. Furthermore, an excessive intracellular Ca2+ level can cause functional defects in subcellular organelles such as the endoplasmic reticulum (ER), lysosomes, and mitochondria, causing metabolic diseases. This review explores how intracellular Ca2+ overload negatively regulates the membrane localization of PIP-binding proteins.
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Affiliation(s)
- Byung-Chul Oh
- Department of Physiology, Lee Gil Ya Cancer and Diabetes Institute, Gachon College of Medicine, Incheon, 21999, Republic of Korea.
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14
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Tribble JR, Hui F, Quintero H, El Hajji S, Bell K, Di Polo A, Williams PA. Neuroprotection in glaucoma: Mechanisms beyond intraocular pressure lowering. Mol Aspects Med 2023; 92:101193. [PMID: 37331129 DOI: 10.1016/j.mam.2023.101193] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/25/2023] [Accepted: 06/04/2023] [Indexed: 06/20/2023]
Abstract
Glaucoma is a common, complex, multifactorial neurodegenerative disease characterized by progressive dysfunction and then loss of retinal ganglion cells, the output neurons of the retina. Glaucoma is the most common cause of irreversible blindness and affects ∼80 million people worldwide with many more undiagnosed. The major risk factors for glaucoma are genetics, age, and elevated intraocular pressure. Current strategies only target intraocular pressure management and do not directly target the neurodegenerative processes occurring at the level of the retinal ganglion cell. Despite strategies to manage intraocular pressure, as many as 40% of glaucoma patients progress to blindness in at least one eye during their lifetime. As such, neuroprotective strategies that target the retinal ganglion cell and these neurodegenerative processes directly are of great therapeutic need. This review will cover the recent advances from basic biology to on-going clinical trials for neuroprotection in glaucoma covering degenerative mechanisms, metabolism, insulin signaling, mTOR, axon transport, apoptosis, autophagy, and neuroinflammation. With an increased understanding of both the basic and clinical mechanisms of the disease, we are closer than ever to a neuroprotective strategy for glaucoma.
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Affiliation(s)
- James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Flora Hui
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Department of Optometry & Vision Sciences, The University of Melbourne, Melbourne, Australia
| | - Heberto Quintero
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Sana El Hajji
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Katharina Bell
- NHMRC Clinical Trials Centre, University of Sydney, Australia; Eye ACP Duke-NUS, Singapore
| | - Adriana Di Polo
- Department of Neuroscience, University of Montreal, Montreal, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, Canada
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden.
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15
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Lear BP, Moore DL. Moving CNS axon growth and regeneration research into human model systems. Front Neurosci 2023; 17:1198041. [PMID: 37425013 PMCID: PMC10324669 DOI: 10.3389/fnins.2023.1198041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/25/2023] [Indexed: 07/11/2023] Open
Abstract
Axon regeneration is limited in the adult mammalian central nervous system (CNS) due to both intrinsic and extrinsic factors. Rodent studies have shown that developmental age can drive differences in intrinsic axon growth ability, such that embryonic rodent CNS neurons extend long axons while postnatal and adult CNS neurons do not. In recent decades, scientists have identified several intrinsic developmental regulators in rodents that modulate growth. However, whether this developmentally programmed decline in CNS axon growth is conserved in humans is not yet known. Until recently, there have been limited human neuronal model systems, and even fewer age-specific human models. Human in vitro models range from pluripotent stem cell-derived neurons to directly reprogrammed (transdifferentiated) neurons derived from human somatic cells. In this review, we discuss the advantages and disadvantages of each system, and how studying axon growth in human neurons can provide species-specific knowledge in the field of CNS axon regeneration with the goal of bridging basic science studies to clinical trials. Additionally, with the increased availability and quality of 'omics datasets of human cortical tissue across development and lifespan, scientists can mine these datasets for developmentally regulated pathways and genes. As there has been little research performed in human neurons to study modulators of axon growth, here we provide a summary of approaches to begin to shift the field of CNS axon growth and regeneration into human model systems to uncover novel drivers of axon growth.
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Affiliation(s)
| | - Darcie L. Moore
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, United States
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16
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Liu P, Chen W, Jiang H, Huang H, Liu L, Fang F, Li L, Feng X, Liu D, Dalal R, Sun Y, Jafar-Nejad P, Ling K, Rigo F, Ye J, Hu Y. Differential effects of SARM1 inhibition in traumatic glaucoma and EAE optic neuropathies. MOLECULAR THERAPY. NUCLEIC ACIDS 2023; 32:13-27. [PMID: 36950280 PMCID: PMC10025007 DOI: 10.1016/j.omtn.2023.02.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/23/2023] [Indexed: 03/03/2023]
Abstract
Optic neuropathy is a group of optic nerve (ON) diseases with progressive degeneration of ON and retinal ganglion cells (RGCs). The lack of neuroprotective treatments is a central challenge for this leading cause of irreversible blindness. SARM1 (sterile α and TIR motif-containing protein 1) has intrinsic nicotinamide adenine dinucleotide (NAD+) hydrolase activity that causes axon degeneration by degrading axonal NAD+ significantly after activation by axon injury. SARM1 deletion is neuroprotective in many, but not all, neurodegenerative disease models. Here, we compare two therapy strategies for SARM1 inhibition, antisense oligonucleotide (ASO) and CRISPR, with germline SARM1 deletion in the neuroprotection of three optic neuropathy mouse models. This study reveals that, similar to germline SARM1 knockout in every cell, local retinal SARM1 ASO delivery and adeno-associated virus (AAV)-mediated RGC-specific CRISPR knockdown of SARM1 provide comparable neuroprotection to both RGC somata and axons in the silicone oil-induced ocular hypertension (SOHU) glaucoma model but only protect RGC axons, not somata, after traumatic ON injury. Surprisingly, neither of these two therapy strategies of SARM1 inhibition nor SARM1 germline knockout (KO) benefits RGC or ON survival in the experimental autoimmune encephalomyelitis (EAE)/optic neuritis model. Our studies therefore suggest that SARM1 inhibition by local ASO delivery or AAV-mediated CRISPR is a promising neuroprotective gene therapy strategy for traumatic and glaucomatous optic neuropathies but not for demyelinating optic neuritis.
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Affiliation(s)
- Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haowen Jiang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liping Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dong Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | | | - Karen Ling
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Frank Rigo
- Ionis Pharmaceuticals, Inc., Carlsbad, CA 92010, USA
| | - Jiangbin Ye
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Corresponding author: Yang Hu, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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17
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Nieuwenhuis B, Laperrousaz E, Tribble JR, Verhaagen J, Fawcett JW, Martin KR, Williams PA, Osborne A. Improving adeno-associated viral (AAV) vector-mediated transgene expression in retinal ganglion cells: comparison of five promoters. Gene Ther 2023:10.1038/s41434-022-00380-z. [PMID: 36635457 DOI: 10.1038/s41434-022-00380-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 12/02/2022] [Accepted: 12/21/2022] [Indexed: 01/14/2023]
Abstract
Recombinant adeno-associated viral vectors (AAVs) are an effective system for gene transfer. AAV serotype 2 (AAV2) is commonly used to deliver transgenes to retinal ganglion cells (RGCs) via intravitreal injection. The AAV serotype however is not the only factor contributing to the effectiveness of gene therapies. Promoters influence the strength and cell-selectivity of transgene expression. This study compares five promoters designed to maximise AAV2 cargo space for gene delivery: chicken β-actin (CBA), cytomegalovirus (CMV), short CMV early enhancer/chicken β-actin/short β-globulin intron (sCAG), mouse phosphoglycerate kinase (PGK), and human synapsin (SYN). The promoters driving enhanced green fluorescent protein (eGFP) were examined in adult C57BL/6J mice eyes and tissues of the visual system. eGFP expression was strongest in the retina, optic nerves and brain when driven by the sCAG and SYN promoters. CBA, CMV, and PGK had moderate expression by comparison. The SYN promoter had almost exclusive transgene expression in RGCs. The PGK promoter had predominant expression in both RGCs and AII amacrine cells. The ubiquitous CBA, CMV, and sCAG promoters expressed eGFP in a variety of cell types across multiple retinal layers including Müller glia and astrocytes. We also found that these promoters could transduce human retina ex vivo, although expression was predominantly in glial cells due to low RGC viability. Taken together, this promoter comparison study contributes to optimising AAV-mediated transduction in the retina, and could be valuable for research in ocular disorders, particularly those with large or complex genetic cargos.
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Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Cambridge Institute for Medical Research, University of Cambridge, Cambridge, CB2 0XY, UK.
| | - Elise Laperrousaz
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - James R Tribble
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Joost Verhaagen
- Laboratory for Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands.,Centre for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - James W Fawcett
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre of Reconstructive Neuroscience, Institute of Experimental Medicine, Prague, Czech Republic
| | - Keith R Martin
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, VIC, Australia.,Ophthalmology, Department of Surgery, University of Melbourne, Melbourne, VIC, Australia
| | - Pete A Williams
- Department of Clinical Neuroscience, Division of Eye and Vision, St. Erik Eye Hospital, Karolinska Institutet, Stockholm, Sweden
| | - Andrew Osborne
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK. .,Ikarovec Ltd, The Norwich Research Park Innovation Centre, Norwich, UK.
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18
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Zheng B, Tuszynski MH. Regulation of axonal regeneration after mammalian spinal cord injury. Nat Rev Mol Cell Biol 2023; 24:396-413. [PMID: 36604586 DOI: 10.1038/s41580-022-00562-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 57.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2022] [Indexed: 01/06/2023]
Abstract
One hundred years ago, Ramón y Cajal, considered by many as the founder of modern neuroscience, stated that neurons of the adult central nervous system (CNS) are incapable of regenerating. Yet, recent years have seen a tremendous expansion of knowledge in the molecular control of axon regeneration after CNS injury. We now understand that regeneration in the adult CNS is limited by (1) a failure to form cellular or molecular substrates for axon attachment and elongation through the lesion site; (2) environmental factors, including inhibitors of axon growth associated with myelin and the extracellular matrix; (3) astrocyte responses, which can both limit and support axon growth; and (4) intraneuronal mechanisms controlling the establishment of an active cellular growth programme. We discuss these topics together with newly emerging hypotheses, including the surprising finding from transcriptomic analyses of the corticospinal system in mice that neurons revert to an embryonic state after spinal cord injury, which can be sustained to promote regeneration with neural stem cell transplantation. These gains in knowledge are steadily advancing efforts to develop effective treatment strategies for spinal cord injury in humans.
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Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
| | - Mark H Tuszynski
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA. .,VA San Diego Research Service, San Diego, CA, USA.
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Axonal Regeneration: Underlying Molecular Mechanisms and Potential Therapeutic Targets. Biomedicines 2022; 10:biomedicines10123186. [PMID: 36551942 PMCID: PMC9775075 DOI: 10.3390/biomedicines10123186] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 11/21/2022] [Accepted: 12/01/2022] [Indexed: 12/13/2022] Open
Abstract
Axons in the peripheral nervous system have the ability to repair themselves after damage, whereas axons in the central nervous system are unable to do so. A common and important characteristic of damage to the spinal cord, brain, and peripheral nerves is the disruption of axonal regrowth. Interestingly, intrinsic growth factors play a significant role in the axonal regeneration of injured nerves. Various factors such as proteomic profile, microtubule stability, ribosomal location, and signalling pathways mark a line between the central and peripheral axons' capacity for self-renewal. Unfortunately, glial scar development, myelin-associated inhibitor molecules, lack of neurotrophic factors, and inflammatory reactions are among the factors that restrict axonal regeneration. Molecular pathways such as cAMP, MAPK, JAK/STAT, ATF3/CREB, BMP/SMAD, AKT/mTORC1/p70S6K, PI3K/AKT, GSK-3β/CLASP, BDNF/Trk, Ras/ERK, integrin/FAK, RhoA/ROCK/LIMK, and POSTN/integrin are activated after nerve injury and are considered significant players in axonal regeneration. In addition to the aforementioned pathways, growth factors, microRNAs, and astrocytes are also commendable participants in regeneration. In this review, we discuss the detailed mechanism of each pathway along with key players that can be potentially valuable targets to help achieve quick axonal healing. We also identify the prospective targets that could help close knowledge gaps in the molecular pathways underlying regeneration and shed light on the creation of more powerful strategies to encourage axonal regeneration after nervous system injury.
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20
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Li L, Feng X, Fang F, Miller DA, Zhang S, Zhuang P, Huang H, Liu P, Liu J, Sredar N, Liu L, Sun Y, Duan X, Goldberg JL, Zhang HF, Hu Y. Longitudinal in vivo Ca 2+ imaging reveals dynamic activity changes of diseased retinal ganglion cells at the single-cell level. Proc Natl Acad Sci U S A 2022; 119:e2206829119. [PMID: 36409915 PMCID: PMC9889883 DOI: 10.1073/pnas.2206829119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 10/05/2022] [Indexed: 11/22/2022] Open
Abstract
Retinal ganglion cells (RGCs) are heterogeneous projection neurons that convey distinct visual features from the retina to brain. Here, we present a high-throughput in vivo RGC activity assay in response to light stimulation using noninvasive Ca2+ imaging of thousands of RGCs simultaneously in living mice. Population and single-cell analyses of longitudinal RGC Ca2+ imaging reveal distinct functional responses of RGCs and unprecedented individual RGC activity conversions during traumatic and glaucomatous degeneration. This study establishes a foundation for future in vivo RGC function classifications and longitudinal activity evaluations using more advanced imaging techniques and visual stimuli under normal, disease, and neural repair conditions. These analyses can be performed at both the population and single-cell levels using temporal and spatial information, which will be invaluable for understanding RGC pathophysiology and identifying functional biomarkers for diverse optic neuropathies.
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Affiliation(s)
- Liang Li
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Xue Feng
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Fang Fang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
- Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha410011, China
| | - David A. Miller
- Department of Biomedical Engineering, Northwestern University, Evanston, IL60208
| | - Shaobo Zhang
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA94143
| | - Pei Zhuang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Haoliang Huang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Pingting Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Junting Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Nripun Sredar
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Liang Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Yang Sun
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Xin Duan
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA94143
| | - Jeffrey L. Goldberg
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
| | - Hao F. Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL60208
| | - Yang Hu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA94304
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21
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Isolation and characterization of novel peptides from fermented products of Lactobacillus for ulcerative colitis prevention and treatment. FOOD SCIENCE AND HUMAN WELLNESS 2022. [DOI: 10.1016/j.fshw.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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A Combined Angelica gigas and Artemisia dracunculus Extract Prevents Dexamethasone-Induced Muscle Atrophy in Mice through the Akt/mTOR/FoxO3a Signaling Pathway. Cells 2022; 11:cells11203245. [PMID: 36291111 PMCID: PMC9600779 DOI: 10.3390/cells11203245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 10/05/2022] [Accepted: 10/13/2022] [Indexed: 11/17/2022] Open
Abstract
Since skeletal muscle atrophy resulting from various causes accelerates the progression of several diseases, its prevention should help maintain health and quality of life. A range of natural materials have been investigated for their potential preventive effects against muscle atrophy. Here, ethanol extracts of Angelica gigas and Artemisia dracunculus were concentrated and dried, and mixed at a ratio of 7:3 to create the mixture CHDT. We then evaluated the potential for CHDT to prevent muscle atrophy and explored the mechanisms involved. CHDT was orally administered to C57BL/6 mice daily for 30 days, and dexamethasone (Dex) was intraperitoneally injected daily to induce muscle atrophy from 14 days after the start of oral administration. We found that CHDT prevented the Dex-induced reductions in muscle strength, mass, and fiber size, likely by upregulating the Akt/mTOR signaling pathway. In addition, CHDT reduced the Dex-induced increase in the serum concentrations of pro-inflammatory cytokines, which directly induce the degradation of muscle proteins. These findings suggest that CHDT could serve as a natural food supplement for the prevention of muscle atrophy.
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23
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Francis D, Burguete AS, Ghabrial AS. Regulation of Archease by the mTOR-vATPase axis. Development 2022; 149:dev200908. [PMID: 36111596 PMCID: PMC9641670 DOI: 10.1242/dev.200908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/23/2022] [Indexed: 01/19/2023]
Abstract
Larval terminal cells of the Drosophila tracheal system generate extensive branched tubes, requiring a huge increase in apical membrane. We discovered that terminal cells compromised for apical membrane expansion - mTOR-vATPase axis and apical polarity mutants - were invaded by the neighboring stalk cell. The invading cell grows and branches, replacing the original single intercellular junction between stalk and terminal cell with multiple intercellular junctions. Here, we characterize disjointed, a mutation in the same phenotypic class. We find that disjointed encodes Drosophila Archease, which is required for the RNA ligase (RtcB) function that is essential for tRNA maturation and for endoplasmic reticulum stress-regulated nonconventional splicing of Xbp1 mRNA. We show that the steady-state subcellular localization of Archease is principally nuclear and dependent upon TOR-vATPase activity. In tracheal cells mutant for Rheb or vATPase loci, Archease localization shifted dramatically from nucleus to cytoplasm. Further, we found that blocking tRNA maturation by knockdown of tRNAseZ also induced compensatory branching. Taken together, these data suggest that the TOR-vATPase axis promotes apical membrane growth in part through nuclear localization of Archease, where Archease is required for tRNA maturation.
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Affiliation(s)
- Deanne Francis
- College of Public Health, Medical and Veterinary Sciences, Division of Tropical Health and Medicine, Department of Biomedicine and Molecular and Cell Biology, James Cook University, Douglas, QLD 4811, Australia
| | - Alondra S. Burguete
- Department of Biomedicine and Molecular and Cell Biology, The Motor Neuron Center, Columbia University Medical Center, VP&S 5th floor, New York, NY 10032, USA
| | - Amin S. Ghabrial
- Department of Pathology and Cell Biology, Columbia University Medical Center, 630 168th Street, Vagellos Physicians and Surgeons 14-401L, New York, NY 10032, USA
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24
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Au NPB, Kumar G, Asthana P, Gao F, Kawaguchi R, Chang RCC, So KF, Hu Y, Geschwind DH, Coppola G, Ma CHE. Clinically relevant small-molecule promotes nerve repair and visual function recovery. NPJ Regen Med 2022; 7:50. [PMID: 36182946 PMCID: PMC9526721 DOI: 10.1038/s41536-022-00233-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 07/01/2022] [Indexed: 12/01/2022] Open
Abstract
Adult mammalian injured axons regenerate over short-distance in the peripheral nervous system (PNS) while the axons in the central nervous system (CNS) are unable to regrow after injury. Here, we demonstrated that Lycium barbarum polysaccharides (LBP), purified from Wolfberry, accelerated long-distance axon regeneration after severe peripheral nerve injury (PNI) and optic nerve crush (ONC). LBP not only promoted intrinsic growth capacity of injured neurons and function recovery after severe PNI, but also induced robust retinal ganglion cell (RGC) survival and axon regeneration after ONC. By using LBP gene expression profile signatures to query a Connectivity map database, we identified a Food and Drug Administration (FDA)-approved small-molecule glycopyrrolate, which promoted PNS axon regeneration, RGC survival and sustained CNS axon regeneration, increased neural firing in the superior colliculus, and enhanced visual target re-innervations by regenerating RGC axons leading to a partial restoration of visual function after ONC. Our study provides insights into repurposing of FDA-approved small molecule for nerve repair and function recovery.
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Affiliation(s)
- Ngan Pan Bennett Au
- grid.35030.350000 0004 1792 6846Department of Neuroscience, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR
| | - Gajendra Kumar
- grid.35030.350000 0004 1792 6846Department of Neuroscience, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR
| | - Pallavi Asthana
- grid.35030.350000 0004 1792 6846Department of Neuroscience, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR
| | - Fuying Gao
- grid.19006.3e0000 0000 9632 6718Department of Psychiatry, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095 USA
| | - Riki Kawaguchi
- grid.19006.3e0000 0000 9632 6718Department of Psychiatry, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095 USA
| | - Raymond Chuen Chung Chang
- grid.194645.b0000000121742757Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR ,grid.194645.b0000000121742757State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR
| | - Kwok Fai So
- grid.194645.b0000000121742757State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR ,grid.194645.b0000000121742757Department of Ophthalmology, The University of Hong Kong, Pokfulam, Hong Kong ,grid.258164.c0000 0004 1790 3548Guangdong-Hong Kong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, China
| | - Yang Hu
- grid.168010.e0000000419368956Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, USA
| | - Daniel H. Geschwind
- grid.19006.3e0000 0000 9632 6718Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 USA ,grid.19006.3e0000 0000 9632 6718Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095 USA
| | - Giovanni Coppola
- grid.19006.3e0000 0000 9632 6718Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095 USA ,grid.19006.3e0000 0000 9632 6718Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095 USA
| | - Chi Him Eddie Ma
- Department of Neuroscience, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong SAR.
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25
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Romaus-Sanjurjo D, Saikia JM, Kim HJ, Tsai KM, Le GQ, Zheng B. Overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins to promote corticospinal axon repair after injury. Cell Death Discov 2022; 8:390. [PMID: 36123349 PMCID: PMC9485247 DOI: 10.1038/s41420-022-01186-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 11/08/2022] Open
Abstract
Although protein synthesis is hypothesized to have a pivotal role in axonal repair after central nervous system (CNS) injury, the role of core components of the protein synthesis machinery has not been examined. Notably, some elongation factors possess non-canonical functions that may further impact axonal repair. Here, we examined whether overexpressing eukaryotic elongation factor 1 alpha (eEF1A) proteins enhances the collateral sprouting of corticospinal tract (CST) neurons after unilateral pyramidotomy, along with the underlying molecular mechanisms. We found that overexpressing eEF1A proteins in CST neurons increased the levels of pS6, an indicator for mTOR activity, but not pSTAT3 and pAKT levels, in neuronal somas. Strikingly, overexpressing eEF1A2 alone, but neither eEF1A1 alone nor both factors simultaneously, increased protein synthesis and actin rearrangement in CST neurons. While eEF1A1 overexpression only slightly enhanced CST sprouting after pyramidotomy, eEF1A2 overexpression substantially enhanced this sprouting. Surprisingly, co-overexpression of both eEF1A1 and eEF1A2 led to a sprouting phenotype similar to wild-type controls, suggesting an antagonistic effect of overexpressing both proteins. These data provide the first evidence that overexpressing a core component of the translation machinery, eEF1A2, enhances CST sprouting, likely by a combination of increased protein synthesis, mTOR signaling and actin cytoskeleton rearrangement.
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Affiliation(s)
- Daniel Romaus-Sanjurjo
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratories (LINCs), Health Research Institute of Santiago de Compostela (IDIS), 15706, Santiago de Compostela, Spain
| | - Junmi M Saikia
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, 92093, USA
| | - Hugo J Kim
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Kristen M Tsai
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Geneva Q Le
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA.
- VA San Diego Research Service, San Diego, CA, 92161, USA.
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26
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Li L, Fang F, Feng X, Zhuang P, Huang H, Liu P, Liu L, Xu AZ, Qi LS, Cong L, Hu Y. Single-cell transcriptome analysis of regenerating RGCs reveals potent glaucoma neural repair genes. Neuron 2022; 110:2646-2663.e6. [PMID: 35952672 PMCID: PMC9391304 DOI: 10.1016/j.neuron.2022.06.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/05/2022] [Accepted: 06/24/2022] [Indexed: 12/17/2022]
Abstract
Axon regeneration holds great promise for neural repair of CNS axonopathies, including glaucoma. Pten deletion in retinal ganglion cells (RGCs) promotes potent optic nerve regeneration, but only a small population of Pten-null RGCs are actually regenerating RGCs (regRGCs); most surviving RGCs (surRGCs) remain non-regenerative. Here, we developed a strategy to specifically label and purify regRGCs and surRGCs, respectively, from the same Pten-deletion mice after optic nerve crush, in which they differ only in their regeneration capability. Smart-Seq2 single-cell transcriptome analysis revealed novel regeneration-associated genes that significantly promote axon regeneration. The most potent of these, Anxa2, acts synergistically with its ligand tPA in Pten-deletion-induced axon regeneration. Anxa2, its downstream effector ILK, and Mpp1 dramatically protect RGC somata and axons and preserve visual function in a clinically relevant model of glaucoma, demonstrating the exciting potential of this innovative strategy to identify novel effective neural repair candidates.
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Affiliation(s)
- Liang Li
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Fang Fang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Xue Feng
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pei Zhuang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pingting Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Liu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Adam Z Xu
- Saratoga High School, Saratoga, CA 95070, USA
| | - Lei S Qi
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Stanford ChEM-H Institute, Stanford University, Stanford, CA 94305, USA
| | - Le Cong
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Wu Tsai Neuroscience Institute, Stanford University, Stanford, CA 94305, USA
| | - Yang Hu
- Spencer Center for Vision Research, Department of Ophthalmology, Byers Eye Institute at Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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Bioactive peptide inhibits acute myeloid leukemia cell proliferation by downregulating ALKBH5-mediated m 6A demethylation of EIF4EBP1 and MLST8 mRNA. Cell Oncol (Dordr) 2022; 45:355-365. [PMID: 35579750 PMCID: PMC9187541 DOI: 10.1007/s13402-022-00666-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 01/05/2022] [Accepted: 02/16/2022] [Indexed: 12/24/2022] Open
Abstract
Purpose N6-methyladenosine (m6A), the most prevalent mRNA modification, plays an essential role in tumorigenesis. Notably, increasing interest has been directed to bioactive peptides (BPs) with antitumor activities. Here, we set out to investigate the potential of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis on prevention and treatment of acute myeloid leukemia (AML). Methods The biological effects of BP on AML cells were detected by MTT and ApoLive-Glo™ multiplex assays. The role of BP in tumor growth was determined by a subcutaneous xenograft model. The ALKBH5/MLST8/EIF4EBP1 axis was identified as a potential BP target in AML via methylated RNA immunoprecipitation sequencing (MeRIP-seq) combined with RNA sequencing (RNA-seq). Western blot, RT-qPCR, MeRIP-qPCR, dual-luciferase reporter and RNA stability assays were performed to validate the function and mode of action of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis. The clinical relevance of the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis in AML was confirmed by TCGA data analysis. Results We found that BP can inhibit AML cell proliferation and promote apoptosis in vitro, and repress AML tumor growth in vivo. Mechanistically, we found that BP downregulated ALKBH5 expression, which in turn repressed m6A demethylation of MLST8 and EIF4EBP1 mRNAs. Reduction of the m6A levels of MLST8 and EIF4EBP1 facilitated MLST8 and EIF4EBP1 mRNA decay, resulting in inhibition of AML cell proliferation. Furthermore, we found that the BP-regulated ALKBH5/MLST8/EIF4EBP1 axis closely correlates with AML patient prognosis. Conclusions Our data indicate that BP can inhibit acute myeloid leukemia cell proliferation by downregulating ALKBH5-mediated m6A demethylation of EIF4EBP1 and MLST8 mRNAs, which may have potential to prevent and treat this disease. Supplementary Information The online version contains supplementary material available at 10.1007/s13402-022-00666-9.
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28
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Fang F, Zhuang P, Feng X, Liu P, Liu D, Huang H, Li L, Chen W, Liu L, Sun Y, Jiang H, Ye J, Hu Y. NMNAT2 is downregulated in glaucomatous RGCs, and RGC-specific gene therapy rescues neurodegeneration and visual function. Mol Ther 2022; 30:1421-1431. [PMID: 35114390 PMCID: PMC9077370 DOI: 10.1016/j.ymthe.2022.01.035] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 12/17/2021] [Accepted: 01/27/2022] [Indexed: 11/19/2022] Open
Abstract
The lack of neuroprotective treatments for retinal ganglion cells (RGCs) and optic nerve (ON) is a central challenge for glaucoma management. Emerging evidence suggests that redox factor NAD+ decline is a hallmark of aging and neurodegenerative diseases. Supplementation with NAD+ precursors and overexpression of NMNAT1, the key enzyme in the NAD+ biosynthetic process, have significant neuroprotective effects. We first profile the translatomes of RGCs in naive mice and mice with silicone oil-induced ocular hypertension (SOHU)/glaucoma by RiboTag mRNA sequencing. Intriguingly, only NMNAT2, but not NMNAT1 or NMNAT3, is significantly decreased in SOHU glaucomatous RGCs, which we confirm by in situ hybridization. We next demonstrate that AAV2 intravitreal injection-mediated overexpression of long half-life NMNAT2 mutant driven by RGC-specific mouse γ-synuclein (mSncg) promoter restores decreased NAD+ levels in glaucomatous RGCs and ONs. Moreover, this RGC-specific gene therapy strategy delivers significant neuroprotection of both RGC soma and axon and preservation of visual function in the traumatic ON crush model and the SOHU glaucoma model. Collectively, our studies suggest that the weakening of NMNAT2 expression in glaucomatous RGCs contributes to a deleterious NAD+ decline, and that modulating RGC-intrinsic NMNAT2 levels by AAV2-mSncg vector is a promising gene therapy for glaucomatous neurodegeneration.
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Affiliation(s)
- Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA; Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha 410011, China
| | - Pei Zhuang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Dong Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Haowen Jiang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jiangbin Ye
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA 94304, USA.
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29
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GIT1 Promotes Axonal Growth in an Inflammatory Environment by Promoting the Phosphorylation of MAP1B. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:7474177. [PMID: 35340202 PMCID: PMC8942666 DOI: 10.1155/2022/7474177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 01/11/2022] [Accepted: 01/25/2022] [Indexed: 11/21/2022]
Abstract
Spinal cord injury (SCI) is a severe traumatic condition. The loss of the bundle of axons involved in motor conduction in the spinal cord after SCI is the main cause of motor function injury. Presently, axon regeneration in the spinal cord has been studied extensively, but it remains unclear how axon growth is regulated in an inflammatory environment at the cellular level. In the present study, GIT1 knockout (KO) mouse neurons were cultured in a microfluidic device to simulate the growth of axons in an inflammatory environment. The molecular regulation of axon growth in an inflammatory environment by GIT1 was then investigated. We found that the axon growth of GIT1 KO mouse neurons was restricted in an inflammatory environment. Further investigations revealed that in both axons and cell bodies in the inflammatory environment, GIT1 phosphorylated ERK, promoted the entry of Nrf2 into the nucleus, and promoted the transcription of MAP1B, thereby increasing the levels of MAP1B and p-MAP1B and promoting axon growth. We also found that MAP1B could be translated locally in axons and transported in cell bodies and axons. In conclusion, we found that GIT1 regulated axon growth in an inflammatory environment. This provided a theoretical basis for axon regeneration in an inflammatory environment after SCI to develop new treatment options for axon regeneration.
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Ni L, Wei Y, Pan J, Li X, Xu B, Deng Y, Yang T, Liu W. Shedding New Light on Methylmercury-induced Neurotoxicity Through the Crosstalk Between Autophagy and Apoptosis. Toxicol Lett 2022; 359:55-64. [PMID: 35122893 DOI: 10.1016/j.toxlet.2022.01.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/23/2021] [Accepted: 01/29/2022] [Indexed: 02/06/2023]
Abstract
Methylmercury (MeHg) is a bio-accumulative global environmental contaminant present in fish and seafood. MeHg accumulates in the aquatic environment and eventually reaches the human system via the food chain by bio-magnification. The central nervous system is the primary target of toxicity and is particularly vulnerable during development. It is well documented that developmental MeHg exposure can lead to neurological alterations, including cognitive and motor dysfunction. Apoptosis is a primary characteristic of MeHg-induced neurotoxicity, and may be regulated by autophagic activity. However, mechanisms mediating the interaction between apoptosis and autophagy remains to be explored. Autophagy is an adaptive response under stressful conditions, and the basal level of autophagy ensures the physiological turnover of old and damaged organelles. Autophagy can regulate cell fate through different crosstalk signaling pathways. A complex interplay between autophagy and apoptosis determines the degree of apoptosis and the progression of MeHg-induced neurotoxicity as demonstrated by pre-clinical models and clinical trials. This review summarizes recent advances in the roles of autophagy and apoptosis in MeHg neurotoxicity and thoroughly explores the relationship between them. The autophagic pathway may be a potential therapeutic target in MeHg neurotoxicity through modulation of apoptosis.
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Affiliation(s)
- Linlin Ni
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Yanfeng Wei
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Jingjing Pan
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Xiaoyang Li
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Bin Xu
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Yu Deng
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Tianyao Yang
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China
| | - Wei Liu
- Department of Environmental Health, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang North New Area, Shenyang 110122, Liaoning, People's Republic of China.
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Chen BR, Wei TW, Tang CP, Sun JT, Shan TK, Fan Y, Yang TT, Li YF, Ma Y, Wang SB, Wang ZM, Wang H, Shi JZ, Liu L, Chen JW, Zhou LH, Du C, Sun R, Wang QM, Wang LS. MNK2-eIF4E axis promotes cardiac repair in the infarcted mouse heart by activating cyclin D1. J Mol Cell Cardiol 2022; 166:91-106. [DOI: 10.1016/j.yjmcc.2022.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2021] [Revised: 02/15/2022] [Accepted: 02/23/2022] [Indexed: 10/19/2022]
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Ji Y, Yu B, Zhang Y, Wu W. The change of microglia numbers within the mice retina, optic nerve and chiasm following intravitreal AAV2-GFP injection. Eur J Ophthalmol 2021; 32:2589-2597. [PMID: 34967226 DOI: 10.1177/11206721211049001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE To explore the optimized concentration of AAV2-GFP for sparse transfection of retinal ganglion cells (RGCs) and optic nerve (ON), and to examine the changes of microglial morphology and distribution in the retina, optic nerve and chiasm after injection. METHODS We defined the optimal concentration of AAV2-GFP for sparse labeling of RGCs and axons in WT mice. We further explored the changes of microglial morphology and distribution in the retina, optic nerve and chiasm after intravitreal injection in CX3CR1+/GFP mice. RESULTS 14 days after intravitreal injection of AAV2-GFP, live imaging of the retina showed that fundus fluorescence was very strong and dense at 2.16 × 1011 VG/retina, 2.16 × 1010 VG/retina, 2.16 × 109 VG/retina. RGCs were sparsely marked at a concentration 1:1000 (2.16 × 108 VG/retina) and fundus fluorescence was weak. The transfected RGCs and axons were unevenly distributed in the retina and significantly more RGCs were transfected near the injection site of AAV2-GFP compared to the other sites of the flat-mounted retina. Microglia density increased significantly in the retina and part of optic nerve, but not in the optic chiasm. The morphology of microglia was largely unchanged. CONCLUSIONS AAV2-GFP was highly efficient and the optimal concentration of sparsely labeled RGCs was 1:1000 (2.16 × 108 VG/retina). After intravitreal injection of AAV2-GFP, the number of microglia increased partly. The morphology of microglia was comparable.
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Affiliation(s)
- Yuanfei Ji
- The Eye Hospital, School of Ophthalmology & Optometry, 26453Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China.,Department of Ophthalmology, 74634Ningbo Medical Treatment Center Li Huili Hospital, Ningbo 315041, Zhejiang Province, China
| | - Bo Yu
- The Eye Hospital, School of Ophthalmology & Optometry, 26453Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
| | - Yikui Zhang
- The Eye Hospital, School of Ophthalmology & Optometry, 26453Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
| | - Wencan Wu
- The Eye Hospital, School of Ophthalmology & Optometry, 26453Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
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Campion TJ, Sheikh IS, Smit RD, Iffland PH, Chen J, Junker IP, Krynska B, Crino PB, Smith GM. Viral expression of constitutively active AKT3 induces CST axonal sprouting and regeneration, but also promotes seizures. Exp Neurol 2021; 349:113961. [PMID: 34953897 DOI: 10.1016/j.expneurol.2021.113961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 12/01/2022]
Abstract
Increasing the intrinsic growth potential of neurons after injury has repeatedly been shown to promote some level of axonal regeneration in rodent models. One of the most studied pathways involves the activation of the PI3K/AKT/mTOR pathways, primarily by reducing the levels of PTEN, a negative regulator of PI3K. Likewise, activation of signal transducer and activator of transcription 3 (STAT3) has previously been shown to boost axonal regeneration and sprouting within the injured nervous system. Here, we examined the regeneration of the corticospinal tract (CST) after cortical expression of constitutively active (ca) Akt3 and STAT3, both separately and in combination. Overexpression of caAkt3 induced regeneration of CST axons past the injury site independent of caSTAT3 overexpression. STAT3 demonstrated improved axon sprouting compared to controls and contributed to a synergistic improvement in effects when combined with Akt3 but failed to promote axonal regeneration as an individual therapy. Despite showing impressive axonal regeneration, animals expressing Akt3 failed to show any functional improvement and deteriorated with time. During this period, we observed progressive Akt3 dose-dependent increase in behavioral seizures. Histology revealed increased phosphorylation of ribosomal S6 protein within the unilateral cortex, increased neuronal size, microglia activation and hemispheric enlargement (hemimegalencephaly).
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Affiliation(s)
- Thomas J Campion
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Imran S Sheikh
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Rupert D Smit
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Philip H Iffland
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jie Chen
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Ian P Junker
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Barbara Krynska
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America
| | - Peter B Crino
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - George M Smith
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America; Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, 3500 North Broad Street, Philadelphia, PA 19140, United States of America.
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Zhao Y, Wang Q, Xie C, Cai Y, Chen X, Hou Y, He L, Li J, Yao M, Chen S, Wu W, Chen X, Hong A. Peptide ligands targeting FGF receptors promote recovery from dorsal root crush injury via AKT/mTOR signaling. Am J Cancer Res 2021; 11:10125-10147. [PMID: 34815808 PMCID: PMC8581430 DOI: 10.7150/thno.62525] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 10/10/2021] [Indexed: 12/27/2022] Open
Abstract
Background: Fibroblast growth factor receptors (FGFRs) are key targets for nerve regeneration and repair. The therapeutic effect of exogenous recombinant FGFs in vivo is limited due to their high molecular weight. Small peptides with low molecular weight, easy diffusion, low immunogenicity, and nontoxic metabolite formation are potential candidates. The present study aimed to develop a novel low-molecular-weight peptide agonist of FGFR to promote nerve injury repair. Methods: Phage display technology was employed to screen peptide ligands targeting FGFR2. The peptide ligand affinity for FGFRs was detected by isothermal titration calorimetry. Structural biology-based computer virtual analysis was used to characterize the interaction between the peptide ligand and FGFR2. The peptide ligand effect on axon growth, regeneration, and behavioral recovery of sensory neurons was determined in the primary culture of sensory neurons and dorsal root ganglia (DRG) explants in vitro and a rat spinal dorsal root injury (DRI) model in vivo. The peptide ligand binding to other membrane receptors was characterized by surface plasmon resonance (SPR) and liquid chromatography-mass spectrometry (LC-MS)/MS. Intracellular signaling pathways primarily affected by the peptide ligand were characterized by phosphoproteomics, and related pathways were verified using specific inhibitors. Results: We identified a novel FGFR-targeting small peptide, CH02, with seven amino acid residues. CH02 activated FGFR signaling through high-affinity binding with the extracellular segment of FGFRs and also had an affinity for several receptor tyrosine kinase (RTK) family members, including VEGFR2. In sensory neurons cultured in vitro, CH02 maintained the survival of neurons and promoted axon growth. Simultaneously, CH02 robustly enhanced nerve regeneration and sensory-motor behavioral recovery after DRI in rats. CH02-induced activation of FGFR signaling promoted nerve regeneration primarily via AKT and ERK signaling downstream of FGFRs. Activation of mTOR downstream of AKT signaling augmented axon growth potential in response to CH02. Conclusion: Our study revealed the significant therapeutic effect of CH02 on strengthening nerve regeneration and suggested a strategy for treating peripheral and central nervous system injuries.
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Nieuwenhuis B, Eva R. Promoting axon regeneration in the central nervous system by increasing PI3-kinase signaling. Neural Regen Res 2021; 17:1172-1182. [PMID: 34782551 PMCID: PMC8643051 DOI: 10.4103/1673-5374.327324] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Much research has focused on the PI3-kinase and PTEN signaling pathway with the aim to stimulate repair of the injured central nervous system. Axons in the central nervous system fail to regenerate, meaning that injuries or diseases that cause loss of axonal connectivity have life-changing consequences. In 2008, genetic deletion of PTEN was identified as a means of stimulating robust regeneration in the optic nerve. PTEN is a phosphatase that opposes the actions of PI3-kinase, a family of enzymes that function to generate the membrane phospholipid PIP3 from PIP2 (phosphatidylinositol (3,4,5)-trisphosphate from phosphatidylinositol (4,5)-bisphosphate). Deletion of PTEN therefore allows elevated signaling downstream of PI3-kinase, and was initially demonstrated to promote axon regeneration by signaling through mTOR. More recently, additional mechanisms have been identified that contribute to the neuron-intrinsic control of regenerative ability. This review describes neuronal signaling pathways downstream of PI3-kinase and PIP3, and considers them in relation to both developmental and regenerative axon growth. We briefly discuss the key neuron-intrinsic mechanisms that govern regenerative ability, and describe how these are affected by signaling through PI3-kinase. We highlight the recent finding of a developmental decline in the generation of PIP3 as a key reason for regenerative failure, and summarize the studies that target an increase in signaling downstream of PI3-kinase to facilitate regeneration in the adult central nervous system. Finally, we discuss obstacles that remain to be overcome in order to generate a robust strategy for repairing the injured central nervous system through manipulation of PI3-kinase signaling.
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Affiliation(s)
- Bart Nieuwenhuis
- John van Geest Center for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard Eva
- John van Geest Center for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Liu P, Huang H, Fang F, Liu L, Li L, Feng X, Chen W, Dalal R, Sun Y, Hu Y. Neuronal NMNAT2 Overexpression Does Not Achieve Significant Neuroprotection in Experimental Autoimmune Encephalomyelitis/Optic Neuritis. Front Cell Neurosci 2021; 15:754651. [PMID: 34707482 PMCID: PMC8542903 DOI: 10.3389/fncel.2021.754651] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 09/10/2021] [Indexed: 11/20/2022] Open
Abstract
Optic neuritis, inflammation, and demyelination of the optic nerve (ON), is one of the most common clinical manifestations of multiple sclerosis; affected patients suffer persistent visual symptoms due to ON degeneration and secondary retinal ganglion cell (RGC) death. The mouse experimental autoimmune encephalomyelitis (EAE) model replicates optic neuritis and significant RGC soma and axon loss. Nicotinamide mononucleotide adenylyltransferases (NMNATs) are NAD+-synthetic enzymes that have been shown to be essential for axon integrity, activation of which significantly delays axonal Wallerian degeneration. NMNAT2, which is enriched in axons, has been proposed as a promising therapeutic target for axon injury-induced neurodegeneration. We therefore investigated whether activation of NMNAT2 can be used as a gene therapy strategy for neuroprotection in EAE/optic neuritis. To avoid the confounding effects in inflammatory cells, which play important roles in EAE initiation and progression, we used an RGC-specific promoter to drive the expression of the long half-life NMNAT2 mutant in mouse RGCs in vivo. However, optical coherence tomography in vivo retina imaging did not reveal significant protection of the ganglion cell complex, and visual function assays, pattern electroretinography, and optokinetic response also showed no improvement in mice with NMNAT2 overexpression. Postmortem histological analysis of retina wholemounts and semithin sections of ON confirmed the in vivo results: NMNAT2 activation in RGCs does not provide significant neuroprotection of RGCs in EAE/optic neuritis. Our studies suggest that a different degenerative mechanism than Wallerian degeneration is involved in autoimmune inflammatory axonopathy and that NMNAT2 may not be a major contributor to this mechanism.
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Affiliation(s)
- Pingting Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Haoliang Huang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Fang Fang
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States.,Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Liang Liu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Liang Li
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Xue Feng
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Wei Chen
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Roopa Dalal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, CA, United States
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Nanomedicine for Neurodegenerative Disorders: Focus on Alzheimer's and Parkinson's Diseases. Int J Mol Sci 2021; 22:ijms22169082. [PMID: 34445784 PMCID: PMC8396516 DOI: 10.3390/ijms22169082] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/17/2021] [Accepted: 08/20/2021] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative disorders involve the slow and gradual degeneration of axons and neurons in the central nervous system (CNS), resulting in abnormalities in cellular function and eventual cellular demise. Patients with these disorders succumb to the high medical costs and the disruption of their normal lives. Current therapeutics employed for treating these diseases are deemed palliative. Hence, a treatment strategy that targets the disease's cause, not just the symptoms exhibited, is desired. The synergistic use of nanomedicine and gene therapy to effectively target the causative mutated gene/s in the CNS disease progression could provide the much-needed impetus in this battle against these diseases. This review focuses on Parkinson's and Alzheimer's diseases, the gene/s and proteins responsible for the damage and death of neurons, and the importance of nanomedicine as a potential treatment strategy. Multiple genes were identified in this regard, each presenting with various mutations. Hence, genome-wide sequencing is essential for specific treatment in patients. While a cure is yet to be achieved, genomic studies form the basis for creating a highly efficacious nanotherapeutic that can eradicate these dreaded diseases. Thus, nanomedicine can lead the way in helping millions of people worldwide to eventually lead a better life.
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The Pathogenesis and Therapeutic Approaches of Diabetic Neuropathy in the Retina. Int J Mol Sci 2021; 22:ijms22169050. [PMID: 34445756 PMCID: PMC8396448 DOI: 10.3390/ijms22169050] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/19/2021] [Accepted: 08/19/2021] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy is a major retinal disease and a leading cause of blindness in the world. Diabetic retinopathy is a neurovascular disease that is associated with disturbances of the interdependent relationship of cells composed of the neurovascular units, i.e., neurons, glial cells, and vascular cells. An impairment of these neurovascular units causes both neuronal and vascular abnormalities in diabetic retinopathy. More specifically, neuronal abnormalities including neuronal cell death and axon degeneration are irreversible changes that are directly related to the vision reduction in diabetic patients. Thus, establishment of neuroprotective and regenerative therapies for diabetic neuropathy in the retina is an emergent task for preventing the blindness of patients with diabetic retinopathy. This review focuses on the pathogenesis of the neuronal abnormalities in diabetic retina including glial abnormalities, neuronal cell death, and axon degeneration. The possible molecular cell death pathways and intrinsic survival and regenerative pathways are also described. In addition, therapeutic approaches for diabetic neuropathy in the retina both in vitro and in vivo are presented. This review should be helpful for providing clues to overcome the barriers for establishing neuroprotection and regeneration of diabetic neuropathy in the retina.
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Abstract
The damage or loss of retinal ganglion cells (RGCs) and their axons accounts for the visual functional defects observed after traumatic injury, in degenerative diseases such as glaucoma, or in compressive optic neuropathies such as from optic glioma. By using optic nerve crush injury models, recent studies have revealed the cellular and molecular logic behind the regenerative failure of injured RGC axons in adult mammals and suggested several strategies with translational potential. This review summarizes these findings and discusses challenges for developing clinically applicable neural repair strategies.
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Affiliation(s)
- Philip R Williams
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri 63110, USA
| | - Larry I Benowitz
- Laboratories for Neuroscience Research in Neurosurgery, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts 02115, USA.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jeffrey L Goldberg
- Spencer Center for Vision Research, Byers Eye Institute, Stanford University, Palo Alto, California 94303, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts 02115, USA; .,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02115, USA.,Department of Neurology, Harvard Medical School, Boston, Massachusetts 02115, USA
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Kitamura N, Fujiwara N, Hayakawa K, Ohama T, Sato K. Protein phosphatase 6 promotes neurite outgrowth by promoting mTORC2 activity in N2a cells. J Biochem 2021; 170:131-138. [PMID: 34314486 DOI: 10.1093/jb/mvab028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/08/2021] [Indexed: 11/14/2022] Open
Abstract
Understanding the molecular mechanism of neuronal differentiation is important to overcome the incurable diseases caused by nervous system damage. Neurite outgrowth is prerequisite for neuronal differentiation and regeneration, and cAMP response element-binding protein (CREB) is one of the major transcriptional factors positively regulating this process. Neuronal differentiation stimuli activate mammalian target of rapamycin (mTOR) complex 2 (mTORC2)/Akt signaling to phosphorylate CREB, however, the precise molecular mechanism of this event has not been fully understood. In this manuscript, we show that neuronal differentiation stimuli increased a protein level of protein phosphatase 6 (PP6), a member of type 2A Ser/Thr protein phosphatases. PP6 knockdown suppressed mTORC2/Akt/CREB signaling and results in failure of neurite outgrowth. SIN1 is a unique component of mTORC2 that enhances mTORC2 activity toward Akt when it is in dephosphorylated form. We found PP6 knockdown increased SIN1 phosphorylation. These data suggest that PP6 may positively regulate neurite outgrowth by dephosphorylating SIN1 to activate mTORC2/Akt/CREB signaling.
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Affiliation(s)
- Nao Kitamura
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | | | - Koji Hayakawa
- Department of Toxicology, Faculty of Veterinary Medicine, Okayama University of Science, 1-3 Ikoinooka, Imabari, 794-8555 Ehime, Japan
| | - Takashi Ohama
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Koichi Sato
- Laboratory of Veterinary Pharmacology, Joint Faculty of Veterinary Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
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Jung K, Kim M, So J, Lee SH, Ko S, Shin D. Farnesoid X Receptor Activation Impairs Liver Progenitor Cell-Mediated Liver Regeneration via the PTEN-PI3K-AKT-mTOR Axis in Zebrafish. Hepatology 2021; 74:397-410. [PMID: 33314176 PMCID: PMC8605479 DOI: 10.1002/hep.31679] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 11/15/2020] [Accepted: 11/29/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND AND AIMS Following mild liver injury, pre-existing hepatocytes replicate. However, if hepatocyte proliferation is compromised, such as in chronic liver diseases, biliary epithelial cells (BECs) contribute to hepatocytes through liver progenitor cells (LPCs), thereby restoring hepatic mass and function. Recently, augmenting innate BEC-driven liver regeneration has garnered attention as an alternative to liver transplantation, the only reliable treatment for patients with end-stage liver diseases. Despite this attention, the molecular basis of BEC-driven liver regeneration remains poorly understood. APPROACH AND RESULTS By performing a chemical screen with the zebrafish hepatocyte ablation model, in which BECs robustly contribute to hepatocytes, we identified farnesoid X receptor (FXR) agonists as inhibitors of BEC-driven liver regeneration. Here we show that FXR activation blocks the process through the FXR-PTEN (phosphatase and tensin homolog)-PI3K (phosphoinositide 3-kinase)-AKT-mTOR (mammalian target of rapamycin) axis. We found that FXR activation blocked LPC-to-hepatocyte differentiation, but not BEC-to-LPC dedifferentiation. FXR activation also suppressed LPC proliferation and increased its death. These defects were rescued by suppressing PTEN activity with its chemical inhibitor and ptena/b mutants, indicating PTEN as a critical downstream mediator of FXR signaling in BEC-driven liver regeneration. Consistent with the role of PTEN in inhibiting the PI3K-AKT-mTOR pathway, FXR activation reduced the expression of pS6, a marker of mTORC1 activation, in LPCs of regenerating livers. Importantly, suppressing PI3K and mTORC1 activities with their chemical inhibitors blocked BEC-driven liver regeneration, as did FXR activation. CONCLUSIONS FXR activation impairs BEC-driven liver regeneration by enhancing PTEN activity; the PI3K-AKT-mTOR pathway controls the regeneration process. Given the clinical trials and use of FXR agonists for multiple liver diseases due to their beneficial effects on steatosis and fibrosis, the detrimental effects of FXR activation on LPCs suggest a rather personalized use of the agonists in the clinic.
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Affiliation(s)
- Kyounghwa Jung
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Minwook Kim
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Juhoon So
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Seung-Hoon Lee
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Sungjin Ko
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA;,Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA
| | - Donghun Shin
- Department of Developmental Biology, McGowan Institute for Regenerative Medicine, Pittsburgh Liver Research Center, University of Pittsburgh, Pittsburgh, PA
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42
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Bhowmick S, Abdul-Muneer PM. PTEN Blocking Stimulates Corticospinal and Raphespinal Axonal Regeneration and Promotes Functional Recovery After Spinal Cord Injury. J Neuropathol Exp Neurol 2021; 80:169-181. [PMID: 33367790 DOI: 10.1093/jnen/nlaa147] [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] [Indexed: 12/15/2022] Open
Abstract
The long-term disabilities associated with spinal cord injury (SCI) are primarily due to the absence of robust neuronal regeneration and functional plasticity. The inability of the axon to regenerate after SCI is contributed by several intrinsic factors that trigger a cascade of molecular growth program and modulates axonal sprouting. Phosphatase and tensin homolog (PTEN) is one of the intrinsic factors contributing to growth failure after SCI, however, the underlying mechanism is not well known. Here, we developed a novel therapeutic approach for treating SCI by suppressing the action of PTEN in a mouse model of hemisection SCI. We have used a novel peptide, PTEN antagonistic peptide (PAP) to block the critical domains of PTEN to demonstrate its ability to potentially promote axon growth. PAP treatment not only enhanced regeneration of corticospinal axons into the caudal spinal cord but also promoted the regrowth of descending serotonergic axons in SCI mice. Furthermore, expression levels of p-mTOR, p-S6, p-Akt, p-Erk, p-GSK, p-PI3K downstream of PTEN signaling pathway were increased significantly in the spinal cord of SCI mice systemically treated with PAP than control TAT peptide-treated mice. Our novel strategy of administering deliverable compounds postinjury may facilitate translational feasibility for central nervous system injury.
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Affiliation(s)
- Saurav Bhowmick
- From the Laboratory of CNS Injury and Molecular Therapy, JFK Neuroscience Institute, Hackensack Meridian Health JFK University Medical Center, Edison, New Jersey
| | - P M Abdul-Muneer
- Department of Neurology, Hackensack Meridian School of Medicine, Nutley, New Jersey
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43
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Zhang T, Ding H, Wang Y, Yuan Z, Zhang Y, Chen G, Xu Y, Chen L. Akt3-mTOR regulates hippocampal neurogenesis in adult mouse. J Neurochem 2021; 159:498-511. [PMID: 34077553 DOI: 10.1111/jnc.15441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 04/16/2021] [Accepted: 05/26/2021] [Indexed: 01/19/2023]
Abstract
Akt signaling has been associated with adult neurogenesis in the hippocampal dentate gyrus (DG). We reported cognitive dysfunction in Akt3 knockout (Akt3-KO) mice with the down-regulation of mTOR activation. However, little is known about the effects of Akt3 signaling on hippocampal neurogenesis. Herein, we show that progenitor cells, neuroblasts, and mature newborn neurons in hippocampal DG expressed Akt3 protein. The Akt3 phosphorylation in hippocampal DG was increased after voluntary wheel running for 7 days in wild-type mice (running WT mice), but not in Akt3-KO mice (running Akt3-KO mice). Subsequently, we observed that the proliferation of progenitor cells was suppressed in Akt3-KO mice and the mTOR inhibitor rapamycin-treated mice, whereas enhanced in running WT mice rather than running Akt3-KO mice. Neurite growth of neuroblasts was impaired in Akt3-KO mice and rapamycin-treated mice. In contrast, neither differentiation of progenitor cells nor migrating of newly generated neurons was altered in Akt3-KO mice or running WT mice. The levels of p70S6K and 4EBP1 phosphorylation were declined in Akt3-KO mice and elevated in running WT mice depending on mTOR activation. Furthermore, telomerase activity, telomere length, and expression of telomerase reverse transcriptase (TERT) were decreased in Akt3-KO mice but increased in running WT mice rather than running Akt3-KO mice, which required the mTOR activation. The study provides in vivo evidence that Akt3-mTOR signaling plays an important role in the proliferation of progenitor cells and neurite growth through positive regulated TERT expression and activation of p70S6K and 4EBP1.
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Affiliation(s)
- Tingting Zhang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Hong Ding
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China.,The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Ya Wang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Zihao Yuan
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Yajie Zhang
- Department of Physiology, Nanjing Medical University, Nanjing, China
| | - Guiquan Chen
- State Key Laboratory of Pharmaceutical Biotechnology, MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Yun Xu
- Department of Neurology, Nanjing Drum Tower Hospital Clinical College of Nanjing Medical University, Nanjing, China
| | - Ling Chen
- Department of Physiology, Nanjing Medical University, Nanjing, China
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44
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Oshitari T. Understanding intrinsic survival and regenerative pathways through in vivo and in vitro studies: implications for optic nerve regeneration. EXPERT REVIEW OF OPHTHALMOLOGY 2021. [DOI: 10.1080/17469899.2021.1912595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Toshiyuki Oshitari
- Department of Ophthalmology and Visual Science, Chiba University Graduate School of Medicine, Japan
- Department of Ophthalmology, International University of Health and Welfare School of Medicine, Narita, Japan
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45
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Hu J, Rodemer W, Zhang G, Jin LQ, Li S, Selzer ME. Chondroitinase ABC Promotes Axon Regeneration and Reduces Retrograde Apoptosis Signaling in Lamprey. Front Cell Dev Biol 2021; 9:653638. [PMID: 33842481 PMCID: PMC8027354 DOI: 10.3389/fcell.2021.653638] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 02/26/2021] [Indexed: 12/22/2022] Open
Abstract
Paralysis following spinal cord injury (SCI) is due to failure of axonal regeneration. It is believed that axon growth is inhibited by the presence of several types of inhibitory molecules in central nervous system (CNS), including the chondroitin sulfate proteoglycans (CSPGs). Many studies have shown that digestion of CSPGs with chondroitinase ABC (ChABC) can enhance axon growth and functional recovery after SCI. However, due to the complexity of the mammalian CNS, it is still unclear whether this involves true regeneration or only collateral sprouting by uninjured axons, whether it affects the expression of CSPG receptors such as protein tyrosine phosphatase sigma (PTPσ), and whether it influences retrograde neuronal apoptosis after SCI. In the present study, we assessed the roles of CSPGs in the regeneration of spinal-projecting axons from brainstem neurons, and in the process of retrograde neuronal apoptosis. Using the fluorochrome-labeled inhibitor of caspase activity (FLICA) method, apoptotic signaling was seen primarily in those large, individually identified reticulospinal (RS) neurons that are known to be “bad-regenerators.” Compared to uninjured controls, the number of all RS neurons showing polycaspase activity increased significantly at 2, 4, 8, and 11 weeks post-transection (post-TX). ChABC application to a fresh TX site reduced the number of polycaspase-positive RS neurons at 2 and 11 weeks post-TX, and also reduced the number of active caspase 3-positive RS neurons at 4 weeks post-TX, which confirmed the beneficial role of ChABC treatment in retrograde apoptotic signaling. ChABC treatment also greatly promoted axonal regeneration at 10 weeks post-TX. Correspondingly, PTPσ mRNA expression was reduced in the perikaryon. Previously, PTPσ mRNA expression was shown to correlate with neuronal apoptotic signaling at 2 and 10 weeks post-TX. In the present study, this correlation persisted after ChABC treatment, which suggests that PTPσ may be involved more generally in signaling axotomy-induced retrograde neuronal apoptosis. Moreover, ChABC treatment caused Akt activation (pAkt-308) to be greatly enhanced in brain post-TX, which was further confirmed in individually identified RS neurons. Thus, CSPG digestion not only enhances axon regeneration after SCI, but also inhibits retrograde RS neuronal apoptosis signaling, possibly by reducing PTPσ expression and enhancing Akt activation.
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Affiliation(s)
- Jianli Hu
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - William Rodemer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Guixin Zhang
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Li-Qing Jin
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.,Department of Anatomy and Cell Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center (Center for Neural Repair and Rehabilitation), Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States.,Department of Neurology, Lewis Katz School of Medicine at Temple University, Philadelphia, PA, United States
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46
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Kim H, Lee J, Cho Y. PDK1 is a negative regulator of axon regeneration. Mol Brain 2021; 14:31. [PMID: 33579325 PMCID: PMC7881570 DOI: 10.1186/s13041-021-00748-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
Axon regeneration in the central nervous system is inefficient. However, the neurons in the peripheral nervous system display robust regeneration after injury, indicating that axonal regeneration is differentially controlled under various conditions. To identify those molecules regulating axon regeneration, comparative analysis from dorsal root ganglion neurons at embryonic or adult stages is utilized, which reveals that PDK1 is functions as a negative regulator of axon regeneration. PDK1 is downregulated in embryonic neurons after axotomy. In contrast, sciatic nerve axotomy upregulated PDK1 at protein levels from adult mice. The knockdown of PDK1 or the chemical inhibition of PDK1 promotes axon regeneration in vitro and in vivo. Here we present PDK1 as a new player to negatively regulate axon regeneration and as a potential target in the development of therapeutic applications.
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Affiliation(s)
- Hyemin Kim
- Department of Life Sciences, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Jinyoung Lee
- Department of Life Sciences, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Yongcheol Cho
- Department of Life Sciences, Korea University, Anam-ro 145, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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Blawat K, Mayr A, Hardt M, Kirschneck C, Nokhbehsaim M, Behl C, Deschner J, Jäger A, Memmert S. Regulation of Autophagic Signaling by Mechanical Loading and Inflammation in Human PDL Fibroblasts. Int J Mol Sci 2020; 21:ijms21249446. [PMID: 33322510 PMCID: PMC7763506 DOI: 10.3390/ijms21249446] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/07/2020] [Accepted: 12/08/2020] [Indexed: 12/19/2022] Open
Abstract
Autophagy (cellular self-consumption) is a crucial adaptation mechanism during cellular stress conditions. This study aimed to examine how this important process is regulated in human periodontal ligament (PDL) fibroblasts by mechanical and inflammatory stress conditions and whether the mammalian target of rapamycin (mTOR) signaling pathway is involved. Autophagy was quantified by flow cytometry. Qualitative protein phosphorylation profiling of the mTOR pathway was carried out. Effects of mTOR regulation were assessed by quantification of important synthesis product collagen 1, cell proliferation and cell death with real-time PCR and flow cytometry. Autophagy as a response to mechanical or inflammatory treatment in PDL fibroblasts was dose and time dependent. In general, autophagy was induced by stress stimulation. Phosphorylation analysis of mTOR showed regulatory influences of mechanical and inflammatory stimulation on crucial target proteins. Regulation of mTOR was also detectable via changes in protein synthesis and cell proliferation. Physiological pressure had cell-protective effects (p = 0.025), whereas overload increased cell death (p = 0.003), which was also promoted in long-term inflammatory treatment (p < 0.001). Our data provide novel insights about autophagy regulation by mechanical and inflammatory stress conditions in human PDL fibroblasts. Our results suggest some involvement of the mTOR pathway in autophagy and cell fate regulation under the named conditions.
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Affiliation(s)
- Kim Blawat
- Center of Dento-Maxillo-Facial Medicine, Department of Orthodontics, University of Bonn Medical Center, 53111 Bonn, Germany; (K.B.); (A.M.); (M.H.); (A.J.)
| | - Alexandra Mayr
- Center of Dento-Maxillo-Facial Medicine, Department of Orthodontics, University of Bonn Medical Center, 53111 Bonn, Germany; (K.B.); (A.M.); (M.H.); (A.J.)
| | - Miriam Hardt
- Center of Dento-Maxillo-Facial Medicine, Department of Orthodontics, University of Bonn Medical Center, 53111 Bonn, Germany; (K.B.); (A.M.); (M.H.); (A.J.)
| | - Christian Kirschneck
- Department of Orthodontics, University Hospital Regensburg, 93042 Regensburg, Germany;
| | - Marjan Nokhbehsaim
- Center of Dento-Maxillo-Facial Medicine, Section of Experimental Dento-Maxillo-Facial Medicine, University of Bonn Medical Center, 53111 Bonn, Germany;
| | - Christian Behl
- The Autophagy Lab, Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University, 55099 Mainz, Germany;
| | - James Deschner
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, 55131 Mainz, Germany;
| | - Andreas Jäger
- Center of Dento-Maxillo-Facial Medicine, Department of Orthodontics, University of Bonn Medical Center, 53111 Bonn, Germany; (K.B.); (A.M.); (M.H.); (A.J.)
| | - Svenja Memmert
- Center of Dento-Maxillo-Facial Medicine, Department of Orthodontics, University of Bonn Medical Center, 53111 Bonn, Germany; (K.B.); (A.M.); (M.H.); (A.J.)
- Correspondence:
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48
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Bui K, Hong YK. Ras Pathways on Prox1 and Lymphangiogenesis: Insights for Therapeutics. Front Cardiovasc Med 2020; 7:597374. [PMID: 33263009 PMCID: PMC7688453 DOI: 10.3389/fcvm.2020.597374] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/12/2020] [Indexed: 12/12/2022] Open
Abstract
Over the past couple of decades, lymphatics research has accelerated and gained a much-needed recognition in pathophysiology. As the lymphatic system plays heavy roles in interstitial fluid drainage, immune surveillance and lipid absorption, the ablation or excessive growth of this vasculature could be associated with many complications, from lymphedema to metastasis. Despite their growing importance in cancer, few anti-lymphangiogenic therapies exist today, as they have yet to pass phase 3 clinical trials and acquire FDA approval. As such, many studies are being done to better define the signaling pathways that govern lymphangiogenesis, in hopes of developing new therapeutic approaches to inhibit or stimulate this process. This review will cover our current understanding of the Ras signaling pathways and their interactions with Prox1, the master transcriptional switch involved in specifying lymphatic endothelial cell fate and lymphangiogenesis, in hopes of providing insights to lymphangiogenesis-based therapies.
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Affiliation(s)
- Khoa Bui
- Department of Surgery, Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Young-Kwon Hong
- Department of Surgery, Department of Biochemistry and Molecular Medicine, Norris Comprehensive Cancer Center, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
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49
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Lisek M, Zylinska L, Boczek T. Ketamine and Calcium Signaling-A Crosstalk for Neuronal Physiology and Pathology. Int J Mol Sci 2020; 21:ijms21218410. [PMID: 33182497 PMCID: PMC7665128 DOI: 10.3390/ijms21218410] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/31/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022] Open
Abstract
Ketamine is a non-competitive antagonist of NMDA (N-methyl-D-aspartate) receptor, which has been in clinical practice for over a half century. Despite recent data suggesting its harmful side effects, such as neuronal loss, synapse dysfunction or disturbed neural network formation, the drug is still applied in veterinary medicine and specialist anesthesia. Several lines of evidence indicate that structural and functional abnormalities in the nervous system caused by ketamine are crosslinked with the imbalanced activity of multiple Ca2+-regulated signaling pathways. Due to its ubiquitous nature, Ca2+ is also frequently located in the center of ketamine action, although the precise mechanisms underlying drug’s negative or therapeutic properties remain mysterious for the large part. This review seeks to delineate the relationship between ketamine-triggered imbalance in Ca2+ homeostasis and functional consequences for downstream processes regulating key aspects of neuronal function.
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50
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Neural Cadherin Plays Distinct Roles for Neuronal Survival and Axon Growth under Different Regenerative Conditions. eNeuro 2020; 7:ENEURO.0325-20.2020. [PMID: 32967889 PMCID: PMC7688304 DOI: 10.1523/eneuro.0325-20.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/26/2020] [Accepted: 08/28/2020] [Indexed: 12/18/2022] Open
Abstract
Growing axons in the CNS often migrate along specific pathways to reach their targets. During embryonic development, this migration is guided by different types of cell adhesion molecules (CAMs) present on the surface of glial cells or other neurons, including the neural cadherin (NCAD). Axons in the adult CNS can be stimulated to regenerate, and travel long distances. Crucially, however, while a few axons are guided effectively through the injured nerve under certain conditions, most axons never migrate properly. The molecular underpinnings of the variable growth, and the glial CAMs that are responsible for CNS axon regeneration remain unclear. Here we used optic nerve crush to demonstrate that NCAD plays multifaceted functions in facilitating CNS axon regeneration. Astrocyte-specific deletion of NCAD dramatically decreases regeneration induced by phosphatase and tensin homolog (PTEN) ablation in retinal ganglion cells (RGCs). Consistent with NCAD’s tendency to act as homodimers, deletion of NCAD in RGCs also reduces regeneration. Deletion of NCAD in astrocytes neither alters RGCs’ mammalian target of rapamycin complex 1 (mTORC1) activity nor lesion size, two factors known to affect regeneration. Unexpectedly, however, we find that NCAD deletion in RGCs reduces PTEN-deletion-induced RGC survival. We further show that NCAD deletion, in either astrocytes or RGCs, has negligible effects on the regeneration induced by ciliary neurotrophic factor (CNTF), suggesting that other CAMs are critical under this regenerative condition. Consistent with this notion, CNTF induces expression various integrins known to mediate cell adhesion. Together, our study reveals multilayered functions of NCAD and a molecular basis of variability in guided axon growth.
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