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Hosen S, Ikeda-Yorifuji I, Yamashita T. Asporin and CD109, expressed in the injured neonatal spinal cord, attenuate axonal re-growth in vitro. Neurosci Lett 2024; 833:137832. [PMID: 38796094 DOI: 10.1016/j.neulet.2024.137832] [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: 01/26/2024] [Revised: 05/17/2024] [Accepted: 05/22/2024] [Indexed: 05/28/2024]
Abstract
Axonal regeneration is restricted in adults and causes irreversible motor dysfunction following spinal cord injury (SCI). In contrast, neonates have prominent regenerative potential and can restore their neural function. Although the distinct cellular responses in neonates have been studied, how they contribute to neural recovery remains unclear. To assess whether the secreted molecules in neonatal SCI can enhance neural regeneration, we re-analyzed the previously performed single-nucleus RNA-seq (snRNA-seq) and focused on Asporin and Cd109, the highly expressed genes in the injured neonatal spinal cord. In the present study, we showed that both these molecules were expressed in the injured spinal cords of adults and neonates. We treated the cortical neurons with recombinant Asporin or CD109 to observe their direct effects on neurons in vitro. We demonstrated that these molecules enhance neurite outgrowth in neurons. However, these molecules did not enhance re-growth of severed axons. Our results suggest that Asporin and CD109 influence neurites at the lesion site, rather than promoting axon regeneration, to restore neural function in neonates after SCI.
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Affiliation(s)
- Sakura Hosen
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Iyo Ikeda-Yorifuji
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan.
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Osaka, Japan; WPI Immunology Frontier Research Center, Osaka University, Suita, Japan; Department of Molecular Neuroscience, Graduate School of Frontier Biosciences, Osaka University, Suita, Japan; Department of Neuro-Medical Science, Graduate School of Medicine, Osaka University, Suita, Japan.
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2
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Wang L, Zhang S, Han Y, Tang S, Li J, Bu L, Zhao D, Deng H. An effective pharmacological hydrogel induces optic nerve repair and improves visual function. SCIENCE CHINA. LIFE SCIENCES 2024; 67:529-542. [PMID: 38041780 DOI: 10.1007/s11427-023-2394-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/09/2023] [Indexed: 12/03/2023]
Abstract
Irreversible eye lesions, such as glaucoma and traumatic optic neuropathy, can cause blindness; however, no effective treatments exist. The optic nerve, in particular, lacks the capacity to spontaneously regenerate, requiring the development of an effective approach for optic nerve repair, which has proven challenging. Here, we demonstrate that a combination of the small molecules 3BDO and trichostatin A (TSA)-which regulate mTOR and HDAC, respectively-packaged in thermosensitive hydrogel for 4-week-sustained release after intravitreal injection, effectively induced optic nerve regeneration in a mouse model of optic nerve crush injury. Moreover, this combination of 3BDO and TSA also protected axon projections and improved visual responses in an old mouse model (11 months old) of glaucoma. Taken together, our data provide a new, local small molecule-based treatment for the effective induction of optic nerve repair, which may represent a foundation for the development of pharmacological methods to treat irreversible eye diseases.
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Affiliation(s)
- Lipeng Wang
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Stem Cell Research Center, State Key Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, 100191, China
- MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Shan Zhang
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Stem Cell Research Center, State Key Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, 100191, China
- MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Yawen Han
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China
| | - Shuo Tang
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Stem Cell Research Center, State Key Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, 100191, China
- MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Jiarui Li
- Department of Ophthalmology, Peking University People's Hospital Eye Diseases and Optometry Institute, Beijing, 100871, China
| | - Lina Bu
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Dongyu Zhao
- Department of Biomedical Informatics, School of Basic Medical Sciences, Peking University, Beijing, 100191, China
| | - Hongkui Deng
- Department of Cell Biology, School of Basic Medical Sciences, Peking University Stem Cell Research Center, State Key Laboratory of Natural and Biomimetic Drugs, Peking University Health Science Center, Beijing, 100191, China.
- MOE Key Laboratory of Cell Proliferation and Differentiation, College of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China.
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
- Changping Laboratory, Beijing, 102206, China.
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3
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Paul D, Agrawal R, Singh S. Alzheimer's disease and clinical trials. J Basic Clin Physiol Pharmacol 2024; 35:31-44. [PMID: 38491747 DOI: 10.1515/jbcpp-2023-0264] [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: 02/28/2024] [Indexed: 03/18/2024]
Abstract
Alzheimer's disease (AD) is spreading its root disproportionately among the worldwide population. Many genes have been identified as the hallmarks of AD. Based upon the knowledge, many clinical trials have been designed and conducted. Attempts have been made to alleviate the pathology associated with AD by targeting the molecular products of these genes. Irrespective of the understanding on the genetic component of AD, many clinical trials have failed and imposed greater challenges on the path of drug discovery. Therefore, this review aims to identify research and review articles to pinpoint the limitations of drug candidates (thiethylperazine, CT1812, crenezumab, CNP520, and lecanemab), which are under or withdrawn from clinical trials. Thorough analysis of the cross-talk pathways led to the identification of many confounding factors, which could interfere with the success of clinical trials with drug candidates such as thiethylperazine, CT1812, crenezumab, and CNP520. Though these drug candidates were enrolled in clinical trials, yet literature review shows many limitations. These limitations raise many questions on the rationale behind the enrollments of these drug candidates in clinical trials. A meticulous prior assessment of the outcome of clinical studies may stop risky clinical trials at their inceptions. This may save time, money, and resources.
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Affiliation(s)
- Deepraj Paul
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
| | - Rohini Agrawal
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
| | - Swati Singh
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
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Suresh S, Singh S A, Rushendran R, Vellapandian C, Prajapati B. Alzheimer's disease: the role of extrinsic factors in its development, an investigation of the environmental enigma. Front Neurol 2023; 14:1303111. [PMID: 38125832 PMCID: PMC10730937 DOI: 10.3389/fneur.2023.1303111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
In the realm of Alzheimer's disease, the most prevalent form of dementia, the impact of environmental factors has ignited intense curiosity due to its substantial burden on global health. Recent investigations have unveiled these environmental factors as key contributors, shedding new light on their profound influence. Notably, emerging evidence highlights the detrimental role of various environmental contaminants in the incidence and progression of Alzheimer's disease. These contaminants encompass a broad spectrum, including air pollutants laden with ozone, neurotoxic metals like lead, aluminum, manganese, and cadmium, pesticides with their insidious effects, and the ubiquitous presence of plastics and microplastics. By meticulously delving into the intricate web connecting environmental pollutants and this devastating neurological disorder, this comprehensive chapter takes a deep dive into their involvement as significant risk factors for Alzheimer's disease. Furthermore, it explores the underlying molecular mechanisms through which these contaminants exert their influence, aiming to unravel the complex interactions that drive the pathogenesis of the disease. Additionally, this chapter proposes potential strategies to mitigate the detrimental effects of these environmental contaminants on brain health, with the ultimate goal of restoring and preserving typical cognitive function. Through this comprehensive exploration, we aim to enhance our understanding of the multifaceted relationship between neurotoxins and Alzheimer's disease, providing a solid foundation for developing innovative in-vivo models and advancing our knowledge of the intricate pathological processes underlying this debilitating condition.
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Affiliation(s)
- Swathi Suresh
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India
| | - Ankul Singh S
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India
| | - Rapuru Rushendran
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India
| | - Chitra Vellapandian
- Department of Pharmacology, SRM College of Pharmacy, SRM Institute of Science and Technology, Kattankulathur, Tamil Nadu, India
| | - Bhupendra Prajapati
- Shree S. K. Patel College of Pharmaceutical Education and Research, Ganpat University, Kherva, Gujarat, India
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Miao W, Su Z, Cheng H. Identification of age-specific biomarkers of spinal cord injury: A bioinformatics analysis of young and aged mice models. Brain Behav 2023; 13:e3293. [PMID: 38032706 PMCID: PMC10726893 DOI: 10.1002/brb3.3293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
BACKGROUND Spinal cord injury (SCI) is a debilitating event that often results in long-term physical damage, disability, and a significant impact on a patient's quality of life. Past research has noted an age-dependent decline in regeneration post-SCI. This study seeks to identify potential biomarkers and enriched pathways in young and aged SCI mouse models. METHODS We retrieved the microarray data of spinal cord samples from SCI mice and control mice from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified using the R software and the Linear Models for Microarray Data (limma) package. The Gene Set Enrichment Analysis (GSEA) determined enrichment differences among gene sets. The Weighted Gene Co-expression Network Analysis (WGCNA) pinpointed clinically significant modules and hub genes in SCI. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was employed to uncover significantly related pathways of crucial genes in SCI. RESULTS We found 2560 DEGs in the young SCI group, comprised of 1733 upregulated RNAs and 827 downregulated RNAs. In the aged SCI group, 3048 DEGs were revealed including 1856 upregulated and 1192 downregulated genes. The GSEA revealed 12 enriched signaling pathways in the young SCI group, such as IL6/JAK/STAT3 signaling, interferon alpha response, and interferon gamma response, and 21 signaling pathways in the aged SCI group such as IL6/JAK/STAT3 signaling, E2F targets, and angiogenesis-related pathways. The WGCNA identified the turquoise module as significantly associated with the clinical traits of both young and aged SCI, and revealed 3181 hub genes. Ultimately, 1858 significant genes in SCI were found, with associated signaling pathways including epithelial-mesenchymal transition (EMT), interferon gamma response, and KARS signaling. CONCLUSION Our study explored the RNA expression patterns and enriched signaling pathways in young and aged SCI mice. These findings may provide potential biomarkers for targeted SCI therapy.
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Affiliation(s)
- Wei Miao
- Department of Neurosurgery, Zhongda Hospital, School of MedicineSoutheast UniversityNanjingP. R. China
| | - Zheng Su
- Department of Neurosurgery, Zhongda Hospital, School of MedicineSoutheast UniversityNanjingP. R. China
| | - Huilin Cheng
- Department of Neurosurgery, Zhongda Hospital, School of MedicineSoutheast UniversityNanjingP. R. China
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Stewart AN, Gensel JC, Jones L, Fouad K. Challenges in Translating Regenerative Therapies for Spinal Cord Injury. Top Spinal Cord Inj Rehabil 2023; 29:23-43. [PMID: 38174141 PMCID: PMC10759906 DOI: 10.46292/sci23-00044s] [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] [Indexed: 01/05/2024]
Abstract
Regenerating the injured spinal cord is a substantial challenge with many obstacles that need to be overcome to achieve robust functional benefits. This abundance of hurdles can partly explain the limited success when applying regenerative intervention treatments in animal models and/or people. In this article, we elaborate on a few of these obstacles, starting with the applicability of animal models and how they compare to the clinical setting. We then discuss the requirement for combinatorial interventions and the associated problems in experimental design, including the addition of rehabilitative training. The article expands on differences in lesion sizes and locations between humans and common animal models, and how this difference can determine the success or failure of an intervention. An additional and frequently overlooked problem in the translation of interventions that applies beyond the field of neuroregeneration is the reporting bias and the lack of transparency in reporting findings. New data mandates are tackling this problem and will eventually result in a more balanced view of the field. Finally, we will discuss strategies to negotiate the challenging course of successful translation to facilitate successful translation of regeneration promoting interventions.
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Affiliation(s)
- Andrew N. Stewart
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, USA
| | - John C. Gensel
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, USA
| | - Linda Jones
- Department of Occupational Therapy, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Karim Fouad
- Department of Physical Therapy, University of Alberta, Edmonton, Canada
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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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8
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Pfyffer D, Zimmermann S, Şimşek K, Kreis R, Freund P, Seif M. Magnetic resonance spectroscopy investigation in the right human hippocampus following spinal cord injury. Front Neurol 2023; 14:1120227. [PMID: 37251221 PMCID: PMC10213741 DOI: 10.3389/fneur.2023.1120227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 04/20/2023] [Indexed: 05/31/2023] Open
Abstract
Objective Preclinical studies have shown that cognitive impairments following spinal cord injury (SCI), such as impaired spatial memory, are linked to inflammation, neurodegeneration, and reduced neurogenesis in the right hippocampus. This cross-sectional study aims to characterize metabolic and macrostructural changes in the right hippocampus and their association to cognitive function in traumatic SCI patients. Methods Within this cross-sectional study, cognitive function was assessed in 28 chronic traumatic SCI patients and 18 age-, sex-, and education-matched healthy controls by a visuospatial and verbal memory test. A magnetic resonance spectroscopy (MRS) and structural MRI protocol was performed in the right hippocampus of both groups to quantify metabolic concentrations and hippocampal volume, respectively. Group comparisons investigated changes between SCI patients and healthy controls and correlation analyses investigated their relationship to memory performance. Results Memory performance was similar in SCI patients and healthy controls. The quality of the recorded MR spectra was excellent in comparison to the best-practice reports for the hippocampus. Metabolite concentrations and volume of the hippocampus measured based on MRS and MRI were not different between two groups. Memory performance in SCI patients and healthy controls was not correlated with metabolic or structural measures. Conclusion This study suggests that the hippocampus may not be pathologically affected at a functional, metabolic, and macrostructural level in chronic SCI. This points toward the absence of significant and clinically relevant trauma-induced neurodegeneration in the hippocampus.
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Affiliation(s)
- Dario Pfyffer
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zürich, Zürich, Switzerland
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Palo Alto, CA, United States
| | - Sandra Zimmermann
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zürich, Zürich, Switzerland
| | - Kadir Şimşek
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Roland Kreis
- Magnetic Resonance Methodology, Institute of Diagnostic and Interventional Neuroradiology, University of Bern, Bern, Switzerland
- Translational Imaging Center (TIC), Swiss Institute for Translational and Entrepreneurial Medicine, Bern, Switzerland
| | - Patrick Freund
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zürich, Zürich, Switzerland
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Maryam Seif
- Spinal Cord Injury Center, Balgrist University Hospital, University of Zürich, Zürich, Switzerland
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
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9
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Adler J. The Axon Initial Segment Plays a Dynamic Role in Peripheral Motor Neuron Synapse Regeneration following Injury. J Neurosci 2023; 43:3199-3201. [PMID: 37137706 PMCID: PMC10162451 DOI: 10.1523/jneurosci.2326-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 05/05/2023] Open
Affiliation(s)
- Joy Adler
- Anschutz Medical Neuroscience Graduate Training Program, University of Colorado, Aurora, Colorado 80045
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Ting DS, Pradhan SP, Barnes E, Ahmed OA, Figueiredo FC. Minimally invasive corneal neurotization for neurotrophic keratopathy: The potential effect of age, denervation chronicity and lesion location. Am J Ophthalmol Case Rep 2023; 29:101804. [PMID: 36718433 PMCID: PMC9883617 DOI: 10.1016/j.ajoc.2023.101804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/01/2023] [Accepted: 01/13/2023] [Indexed: 01/23/2023] Open
Abstract
Purpose Neurotrophic keratopathy (NK) is an uncommon but challenging clinical condition characterized by altered corneal nerves and sensation leading to corneal damage. Corneal neurotization, a surgical technique that aims to "re-innervate" the cornea, has gained increasing popularity in view of the potential to permanently improve or even restore the normal corneal sensation. In this study, we aimed to report the outcomes of two cases of NK that underwent indirect minimally invasive corneal neurotization (MICN) with a sural nerve autograft, and to provide plausible explanations for the observed clinical outcomes. Observations This was an interventional case series of two patients who underwent MICN for severe unilateral NK. The MICN technique was adapted from the technique originally described by Elbaz et al., in 2014. Clinical severity of NK was graded according to Mackie's grading system. Corneal sensation was measured using the Cochet-Bonnet esthesiometer (0-60mm) and corneal nerves were examined using in vivo confocal microscopy (IVCM) with Heidelberg HRT3 Rostock Corneal Module. Patient 1 was a 70-year-old man with a right grade III NK following trigeminal nerve decompression for trigeminal neuralgia. Patient 2 was a 62-year-old man with a left grade II NK following a left-sided acoustic neuroma resection. The denervation time was 23 years for both patients. Following the MICN surgery, none of the patients achieved sustained improvement in the corneal sensation (though patient 1 achieved a transient improvement in central corneal sensation to 20mm at 4 months' postoperative before returning to 0mm at 6 months' postoperative). IVCM did not reveal any changes in the corneal nerve density and morphology post-MICN. Conclusions and Importance Based on our observations and the literature, we postulate that long denervation time, proximal injury to the trigeminal nerve and older patient age may serve as poor prognostic factors for MICN. As CN is being increasingly adopted in clinical practice for treating NK, understanding of these potential factors will facilitate better risk-benefit stratification and patient counselling. Future larger studies are required to elucidate these findings.
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Affiliation(s)
- Darren S.J. Ting
- Birmingham and Midland Eye Centre, Birmingham, UK
- Academic Unit of Ophthalmology, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
- Academic Ophthalmology, School of Medicine, University of Nottingham, Nottingham, UK
| | - Sayali P. Pradhan
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Eric Barnes
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Omar A. Ahmed
- Department of Plastic Surgery, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Francisco C. Figueiredo
- Department of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, UK
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Corresponding author. partment of Ophthalmology, Royal Victoria Infirmary, Newcastle upon Tyne, NE1 4LP, UK.
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11
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Geoffroy CG, Meves JM, Kim HJM, Romaus-Sanjurjo D, Sutherland TC, Li JJ, Suen J, Sanchez JJ, Zheng B. Targeting PTEN but not SOCS3 resists an age-dependent decline in promoting axon sprouting. iScience 2022; 25:105383. [PMID: 36339257 PMCID: PMC9626739 DOI: 10.1016/j.isci.2022.105383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/29/2022] [Accepted: 10/13/2022] [Indexed: 11/27/2022] Open
Abstract
Axonal repair is critical for functional recovery after injury of the CNS. We previously reported that neuronal PTEN deletion exhibits an age-dependent decline in promoting axon regeneration from the corticospinal tract (CST). How sprouting of uninjured axons, a naturally occurring form of axonal repair, is impacted by age is unknown. We assessed CST sprouting after unilateral pyramidotomy in PTEN and/or SOCS3-deleted mice at different ages. While PTEN deletion enhances sprouting independently of age, SOCS3 deletion loses its sprouting-promoting effect with age. The synergistic effect of PTEN/SOCS3 co-deletion on CST sprouting is rapidly lost with increased age. Overall, promoting sprouting appears more robust across age than regeneration, yet distinct molecular pathways are differentially impacted by age. Importantly, six-week delayed PTEN deletion promotes CST sprouting across age groups, supporting a clinically relevant time frame for this neural repair strategy independently of age.
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Affiliation(s)
- Cédric G. Geoffroy
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Jessica M. Meves
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - Hugo Jae Mun Kim
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Daniel Romaus-Sanjurjo
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Theresa C. Sutherland
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Jeffrey J. Li
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Juliet Suen
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Joshua J. Sanchez
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - 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
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12
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Islam A, Tom VJ. The use of viral vectors to promote repair after spinal cord injury. Exp Neurol 2022; 354:114102. [PMID: 35513025 DOI: 10.1016/j.expneurol.2022.114102] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 04/21/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Spinal cord injury (SCI) is a devastating event that can permanently disrupt multiple modalities. Unfortunately, the combination of the inhibitory environment at a central nervous system (CNS) injury site and the diminished intrinsic capacity of adult axons for growth results in the failure for robust axonal regeneration, limiting the ability for repair. Delivering genetic material that can either positively or negatively modulate gene expression has the potential to counter the obstacles that hinder axon growth within the spinal cord after injury. A popular gene therapy method is to deliver the genetic material using viral vectors. There are considerations when deciding on a viral vector approach for a particular application, including the type of vector, as well as serotypes, and promoters. In this review, we will discuss some of the aspects to consider when utilizing a viral vector approach to as a therapy for SCI. Additionally, we will discuss some recent applications of gene therapy to target extrinsic and/or intrinsic barriers to promote axon regeneration after SCI in preclinical models. While still in early stages, this approach has potential to treat those living with SCI.
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Affiliation(s)
- Ashraful Islam
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Philadelphia, PA, USA
| | - Veronica J Tom
- Drexel University College of Medicine, Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Philadelphia, PA, USA.
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13
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Stewart A, Glaser E, Mott CA, Bailey WM, Sulllivan PG, Patel S, Gensel J. Advanced Age and Neurotrauma Diminish Glutathione and Impair Antioxidant Defense after Spinal Cord Injury. J Neurotrauma 2022; 39:1075-1089. [PMID: 35373589 PMCID: PMC9347421 DOI: 10.1089/neu.2022.0010] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Andrew Stewart
- University of Kentucky, Physiology, 741 S. Limestone Street, BBSRB B483, Lexington, Kentucky, United States, 40536-0509,
| | - Ethan Glaser
- University of Kentucky, Physiology, Lexington, Kentucky, United States,
| | - Caitlin A Mott
- University of Kentucky, Physiology, Lexington, Kentucky, United States,
| | - William M Bailey
- University of Kentucky, Spinal Cord and Brain Injury Research Center, Physiology, Lexington, Kentucky, United States
| | - Patrick G Sulllivan
- University of Kentucky College of Medicine, Spinal Cord & Brain Injury Research Cent, 475 BBSRB, Lexington, United States, 40536-0509,
| | - Samir Patel
- University of Kentucky, 4530, Spinal Cord and Brain Injury Research Center, Physiology, Lexington, Kentucky, United States
| | - John Gensel
- University of Kentucky, Physiology, 741 S. Limestone Street, B436 BBSRB, Lexington, Kentucky, United States, 40536-0509
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14
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Stewart A, Glaser E, Bailey WM, Gensel J. Immunoglobulin G is Increased in the Injured Spinal Cord in a Sex and Age Dependent Manner. J Neurotrauma 2022; 39:1090-1098. [PMID: 35373588 PMCID: PMC9347383 DOI: 10.1089/neu.2022.0011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
There are limited studies examining age and sex as biological variables in the pathophysiology of spinal cord injury (SCI). The use of older animals and sex-balanced groups in SCI models is increasingly prioritized to better match clinical demographics. Including older animals in SCI studies is technically challenging, and outcomes are unpredictable with respect to biological and treatment responses. Incidental discoveries that are unrelated to the question under investigation often emerge while including age and sex as biological variables. When probing tissue homogenates on Western blots of 4- and 14-month-old (MO) mice, we identified a sex- and age-dependent increase in immunoglobulin G (IgG) within the spinal cords of older, 14-MO mice acutely after SCI, with females having more IgG compared with males. We further probed to determine whether differences in hemorrhage exist between sexes or ages by evaluating hemoglobin within spinal homogenates. Differences in hemoglobin between sexes and ages were not consistently observed. Because IgG was elevated in an age- and sex-dependent manner without of evidence of differences in hemorrhage, our findings point to potential pre-existing differences in IgG within mouse plasma in an age- and sex-dependent manner. This report has identified age- and sex-dependent differences in infiltrating IgG into the injured spinal cord environment that may affect injury and recovery processes. Our findings highlight that systemic contributions to SCI can be sex- and age-dependent and illustrate the value of reporting incidental discoveries.
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Affiliation(s)
- Andrew Stewart
- University of Kentucky, Physiology, 741 S. Limestone Street, BBSRB B483, Lexington, Kentucky, United States, 40536-0509,
| | - Ethan Glaser
- University of Kentucky, Physiology, Lexington, Kentucky, United States,
| | - William M Bailey
- University of Kentucky, Spinal Cord and Brain Injury Research Center, Physiology, Lexington, Kentucky, United States
| | - John Gensel
- University of Kentucky, Physiology, 741 S. Limestone Street, B436 BBSRB, Lexington, Kentucky, United States, 40536-0509
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15
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Kopp MA, Lübstorf T, Blex C, Schwab JM, Grittner U, Auhuber T, Ekkernkamp A, Niedeggen A, Prillip E, Hoppe M, Ludwig J, Kreutzträger M, Liebscher T. Association of age with the timing of acute spine surgery-effects on neurological outcome after traumatic spinal cord injury. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2022; 31:56-69. [PMID: 34533643 DOI: 10.1007/s00586-021-06982-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 08/02/2021] [Accepted: 08/24/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate the association of age with delay in spine surgery and the effects on neurological outcome after traumatic spinal cord injury (SCI). METHODS Ambispective cohort study (2011-2017) in n = 213 patients consecutively enrolled in a Level I trauma center with SCI care in a metropolitan region in Germany. Age-related differences in the injury to surgery interval and conditions associated with its delay (> 12 h after SCI) were explored using age categories or continuous variables and natural cubic splines. Effects of delayed surgery or age with outcome were analyzed using multiple logistic regression. RESULTS The median age of the study population was 58.8 years (42.0-74.6 IQR). Older age (≥ 75y) was associated with a prolonged injury to surgery interval of 22.8 h (7.2-121.3) compared to 6.6 h (4.4-47.9) in younger patients (≤ 44y). Main reasons for delayed surgery in older individuals were secondary referrals and multimorbidity. Shorter time span to surgery (≤ 12 h) was associated with higher rates of ASIA impairment scale (AIS) conversion (OR 4.22, 95%CI 1.85-9.65), as mirrored by adjusted spline curves (< 20 h 20-25%, 20-60 h 10-20%, > 60 h < 10% probability of AIS conversion). In incomplete SCI, the probability of AIS conversion was lower in older patients [e.g., OR 0.09 (0.02-0.44) for'45-59y' vs.' ≤ 44y'], as confirmed by spline curves (< 40y 20-80%, ≥ 40y 5-20% probability). CONCLUSION Older patient age complexifies surgical SCI care and research. Tackling secondary referral to Level I trauma centers and delayed spine surgery imposes as tangible opportunity to improve the outcome of older SCI patients.
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Affiliation(s)
- Marcel A Kopp
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany.
- Berlin Institute of Health, QUEST-Center for Transforming Biomedical Research, Berlin, Germany.
| | - Tom Lübstorf
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Christian Blex
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Jan M Schwab
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Belford Center for Spinal Cord Injury, Departments of Neurology, Physical Medicine and Rehabilitation, and Neurosciences, The Neuroscience Institute, The Ohio State University, Wexner Medical Center, Columbus, OH, USA
| | - Ulrike Grittner
- Institute of Biometry and Clinical Epidemiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
| | - Thomas Auhuber
- Medical Management, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
- University of Applied Sciences of the German Statutory Accident Insurance (HGU), Bad Hersfeld, Germany
| | - Axel Ekkernkamp
- Clinic for Trauma Surgery and Orthopaedics, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Andreas Niedeggen
- Brandenburg Center for Spinal Cord Injuries, Kliniken Beelitz, Beelitz-Heilstätten, Germany
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Erik Prillip
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Magdalena Hoppe
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Johanna Ludwig
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Martin Kreutzträger
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
| | - Thomas Liebscher
- Clinical and Experimental Spinal Cord Injury Research (Neuroparaplegiology), Department of Neurology and Experimental Neurology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Zu Berlin, and Berlin Institute of Health, Berlin, Germany
- Treatment Centre for Spinal Cord Injuries, BG Hospital Unfallkrankenhaus Berlin, Berlin, Germany
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16
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Sutherland TC, Sefiani A, Horvat D, Huntington TE, Lei Y, West AP, Geoffroy CG. Age-Dependent Decline in Neuron Growth Potential and Mitochondria Functions in Cortical Neurons. Cells 2021; 10:1625. [PMID: 34209640 PMCID: PMC8306398 DOI: 10.3390/cells10071625] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 12/23/2022] Open
Abstract
The age of incidence of spinal cord injury (SCI) and the average age of people living with SCI is continuously increasing. However, SCI is extensively modeled in young adult animals, hampering translation of research to clinical applications. While there has been significant progress in manipulating axon growth after injury, the impact of aging is still unknown. Mitochondria are essential to successful neurite and axon growth, while aging is associated with a decline in mitochondrial functions. Using isolation and culture of adult cortical neurons, we analyzed mitochondrial changes in 2-, 6-, 12- and 18-month-old mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however, mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest that dysfunctional mitochondria in older neurons may be associated with the age-dependent reduction in neurite growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can combine to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.
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Affiliation(s)
- Theresa C. Sutherland
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Arthur Sefiani
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Darijana Horvat
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Taylor E. Huntington
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
| | - Yuanjiu Lei
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA; (Y.L.); (A.P.W.)
| | - A. Phillip West
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA; (Y.L.); (A.P.W.)
| | - Cédric G. Geoffroy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX 77807, USA; (T.C.S.); (A.S.); (D.H.); (T.E.H.)
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17
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Tran AP, Warren PM, Silver J. New insights into glial scar formation after spinal cord injury. Cell Tissue Res 2021; 387:319-336. [PMID: 34076775 PMCID: PMC8975767 DOI: 10.1007/s00441-021-03477-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 05/20/2021] [Indexed: 02/06/2023]
Abstract
Severe spinal cord injury causes permanent loss of function and sensation throughout the body. The trauma causes a multifaceted torrent of pathophysiological processes which ultimately act to form a complex structure, permanently remodeling the cellular architecture and extracellular matrix. This structure is traditionally termed the glial/fibrotic scar. Similar cellular formations occur following stroke, infection, and neurodegenerative diseases of the central nervous system (CNS) signifying their fundamental importance to preservation of function. It is increasingly recognized that the scar performs multiple roles affecting recovery following traumatic injury. Innovative research into the properties of this structure is imperative to the development of treatment strategies to recover motor function and sensation following CNS trauma. In this review, we summarize how the regeneration potential of the CNS alters across phyla and age through formation of scar-like structures. We describe how new insights from next-generation sequencing technologies have yielded a more complex portrait of the molecular mechanisms governing the astrocyte, microglial, and neuronal responses to injury and development, especially of the glial component of the scar. Finally, we discuss possible combinatorial therapeutic approaches centering on scar modulation to restore function after severe CNS injury.
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Affiliation(s)
- Amanda Phuong Tran
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Philippa Mary Warren
- Wolfson Centre for Age Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, Guy's Campus, London Bridge, London, UK
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA.
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18
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Wang B, Huang M, Shang D, Yan X, Zhao B, Zhang X. Mitochondrial Behavior in Axon Degeneration and Regeneration. Front Aging Neurosci 2021; 13:650038. [PMID: 33762926 PMCID: PMC7982458 DOI: 10.3389/fnagi.2021.650038] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
Mitochondria are organelles responsible for bioenergetic metabolism, calcium homeostasis, and signal transmission essential for neurons due to their high energy consumption. Accumulating evidence has demonstrated that mitochondria play a key role in axon degeneration and regeneration under physiological and pathological conditions. Mitochondrial dysfunction occurs at an early stage of axon degeneration and involves oxidative stress, energy deficiency, imbalance of mitochondrial dynamics, defects in mitochondrial transport, and mitophagy dysregulation. The restoration of these defective mitochondria by enhancing mitochondrial transport, clearance of reactive oxidative species (ROS), and improving bioenergetic can greatly contribute to axon regeneration. In this paper, we focus on the biological behavior of axonal mitochondria in aging, injury (e.g., traumatic brain and spinal cord injury), and neurodegenerative diseases (Alzheimer's disease, AD; Parkinson's disease, PD; Amyotrophic lateral sclerosis, ALS) and consider the role of mitochondria in axon regeneration. We also compare the behavior of mitochondria in different diseases and outline novel therapeutic strategies for addressing abnormal mitochondrial biological behavior to promote axonal regeneration in neurological diseases and injuries.
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Affiliation(s)
- Biyao Wang
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Minghao Huang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Dehao Shang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xu Yan
- The VIP Department, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Baohong Zhao
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
| | - Xinwen Zhang
- Center of Implant Dentistry, School and Hospital of Stomatology, China Medical University, Liaoning Provincial Key Laboratory of Oral Diseases, Shenyang, China
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19
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Birnbaum A, Sodders M, Bouska M, Chang K, Kang P, McNeill E, Bai H. FOXO Regulates Neuromuscular Junction Homeostasis During Drosophila Aging. Front Aging Neurosci 2021; 12:567861. [PMID: 33584240 PMCID: PMC7874159 DOI: 10.3389/fnagi.2020.567861] [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: 05/30/2020] [Accepted: 12/04/2020] [Indexed: 12/17/2022] Open
Abstract
The transcription factor foxo is a known regulator of lifespan extension and tissue homeostasis. It has been linked to the maintenance of neuronal processes across many species and has been shown to promote youthful characteristics by regulating cytoskeletal flexibility and synaptic plasticity at the neuromuscular junction (NMJ). However, the role of foxo in aging neuromuscular junction function has yet to be determined. We profiled adult Drosophila foxo- null mutant abdominal ventral longitudinal muscles and found that young mutants exhibited morphological profiles similar to those of aged wild-type flies, such as larger bouton areas and shorter terminal branches. We also observed changes to the axonal cytoskeleton and an accumulation of late endosomes in foxo null mutants and motor neuron-specific foxo knockdown flies, similar to those of aged wild-types. Motor neuron-specific overexpression of foxo can delay age-dependent changes to NMJ morphology, suggesting foxo is responsible for maintaining NMJ integrity during aging. Through genetic screening, we identify several downstream factors mediated through foxo-regulated NMJ homeostasis, including genes involved in the MAPK pathway. Interestingly, the phosphorylation of p38 was increased in the motor neuron-specific foxo knockdown flies, suggesting foxo acts as a suppressor of p38/MAPK activation. Our work reveals that foxo is a key regulator for NMJ homeostasis, and it may maintain NMJ integrity by repressing MAPK signaling.
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Affiliation(s)
- Allison Birnbaum
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States.,Department of Cell, Developmental and Integrative Biology, University of Alabama Birmingham, Birmingham, AL, United States
| | - Maggie Sodders
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Mark Bouska
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Kai Chang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Ping Kang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
| | - Elizabeth McNeill
- Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, United States
| | - Hua Bai
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, United States
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20
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Krzesniak NE, Sarnowska A, Figiel-Dabrowska A, Osiak K, Domanska-Janik K, Noszczyk BH. Secondary release of the peripheral nerve with autologous fat derivates benefits for functional and sensory recovery. Neural Regen Res 2021; 16:856-864. [PMID: 33229720 PMCID: PMC8178762 DOI: 10.4103/1673-5374.297081] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The reconstruction of nerve continuity after traumatic nerve injury is the gold standard in hand surgery. Immediate, tension-free, end-to-end nerve suture ensures the best prognosis. The recovery is mostly promising; however, in a few cases, insufficient outcomes in motor or sensory function are observed. Intra- and extra-fascicular scarring accompanies the nerve regeneration process and limits final outcomes. Secondary nerve release in those cases is recommended. Unfortunately, scarring recurrence cannot be eliminated after secondary revision and neurolysis. The supportive influences of mesenchymal stem cells in the process of nerve regeneration were observed in many preclinical studies. However, a limited number of studies in humans have analyzed the clinical usage of mesenchymal stem cells in peripheral nerve reconstruction and revisions. The objective of this study was to evaluate the effects of undifferentiated adipose-derived stromal/stem cell injection during a last-chance surgery (neurolysis, nerve release) on a previously reconstructed nerve. Three patients (one female, two males; mean age 59 ± 4.5 years at the time of injury), who experienced failure of reconstructions of median and ulnar nerves, were included in this study. During the revision surgery, nerve fascicles were released, and adipose-derived stromal/stem cells were administered through microinjections along the fascicles and around the adjacent tissues after external neurolysis. During 36 months of follow-up, patients noticed gradual signs of sensory and in consequence functional recovery. No adverse effects were observed. Simultaneous nerve release with adipose-derived stromal/stem cells support is a promising method in patients who need secondary nerve release after nerve reconstruction. This method can constitute an alternative procedure in patients experiencing recovery failure and allow improvement in cases of limited nerve regeneration. The study protocol was approved by the Institutional Review Board (IRB) at the Centre of Postgraduate Medical Education (No. 62/PB/2016) on September 14, 2016.
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Affiliation(s)
- Natalia E Krzesniak
- Department of Plastic and Reconstructive Surgery, Center of Postgraduate Medical Education, Prof. W. Orlowski Memorial Hospital, Warsaw, Poland
| | - Anna Sarnowska
- Mossakowski Medical Research Center, Polish Academy of Sciences, Warsaw, Poland
| | | | - Katarzyna Osiak
- Department of Plastic and Reconstructive Surgery, Center of Postgraduate Medical Education, Prof. W. Orlowski Memorial Hospital, Warsaw, Poland
| | | | - Bartłomiej H Noszczyk
- Department of Plastic and Reconstructive Surgery, Center of Postgraduate Medical Education, Prof. W. Orlowski Memorial Hospital, Warsaw, Poland
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21
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Sutherland TC, Geoffroy CG. Are mitochondria the key to reduce the age-dependent decline in axon growth after spinal cord injury? Neural Regen Res 2021; 16:1444-1445. [PMID: 33318447 PMCID: PMC8284276 DOI: 10.4103/1673-5374.301016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Theresa C Sutherland
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, USA
| | - Cédric G Geoffroy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, USA
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22
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Lee J, Cho Y. Comparative gene expression profiling reveals the mechanisms of axon regeneration. FEBS J 2020; 288:4786-4797. [PMID: 33248003 DOI: 10.1111/febs.15646] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/17/2020] [Accepted: 11/25/2020] [Indexed: 01/03/2023]
Abstract
Axons are vulnerable to injury, potentially leading to degeneration or neuronal death. While neurons in the central nervous system fail to regenerate, neurons in the peripheral nervous system are known to regenerate. Since it has been shown that injury-response signal transduction is mediated by gene expression changes, expression profiling is a useful tool to understand the molecular mechanisms of regeneration. Axon regeneration is regulated by injury-responsive genes induced in both neurons and their surrounding non-neuronal cells. Thus, an experimental setup for the comparative analysis between regenerative and nonregenerative conditions is essential to identify ideal targets for the promotion of regeneration-associated genes and to understand the mechanisms of axon regeneration. Here, we review the original research that shows the key factors regulating axon regeneration, in particular by using comparative gene expression profiling in diverse systems.
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Affiliation(s)
- Jinyoung Lee
- Laboratory of Axon Regeneration & Degeneration, Department of Life Sciences, Korea University, Seoul, Korea
| | - Yongcheol Cho
- Laboratory of Axon Regeneration & Degeneration, Department of Life Sciences, Korea University, Seoul, Korea
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23
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Vanhunsel S, Beckers A, Moons L. Designing neuroreparative strategies using aged regenerating animal models. Ageing Res Rev 2020; 62:101086. [PMID: 32492480 DOI: 10.1016/j.arr.2020.101086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/13/2020] [Accepted: 05/08/2020] [Indexed: 12/13/2022]
Abstract
In our ever-aging world population, the risk of age-related neuropathies has been increasing, representing both a social and economic burden to society. Since the ability to regenerate in the adult mammalian central nervous system is very limited, brain trauma and neurodegeneration are often permanent. As a consequence, novel scientific challenges have emerged and many research efforts currently focus on triggering repair in the damaged or diseased brain. Nevertheless, stimulating neuroregeneration remains ambitious. Even though important discoveries have been made over the past decades, they did not translate into a therapy yet. Actually, this is not surprising; while these disorders mainly manifest in aged individuals, most of the research is being performed in young animal models. Aging of neurons and their environment, however, greatly affects the central nervous system and its capacity to repair. This review provides a detailed overview of the impact of aging on central nervous system functioning and regeneration potential, both in non-regenerating and spontaneously regenerating animal models. Additionally, we highlight the need for aging animal models with regenerative capacities in the search for neuroreparative strategies.
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Affiliation(s)
- Sophie Vanhunsel
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - An Beckers
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium
| | - Lieve Moons
- Laboratory of Neural Circuit Development and Regeneration, Animal Physiology and Neurobiology Section, Department of Biology, KU Leuven, Leuven, Belgium.
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24
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Stewart AN, MacLean SM, Stromberg AJ, Whelan JP, Bailey WM, Gensel JC, Wilson ME. Considerations for Studying Sex as a Biological Variable in Spinal Cord Injury. Front Neurol 2020; 11:802. [PMID: 32849242 PMCID: PMC7419700 DOI: 10.3389/fneur.2020.00802] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/26/2020] [Indexed: 12/13/2022] Open
Abstract
In response to NIH initiatives to investigate sex as a biological variable in preclinical animal studies, researchers have increased their focus on male and female differences in neurotrauma. Inclusion of both sexes when modeling neurotrauma is leading to the identification of novel areas for therapeutic and scientific exploitation. Here, we review the organizational and activational effects of sex hormones on recovery from injury and how these changes impact the long-term health of spinal cord injury (SCI) patients. When determining how sex affects SCI it remains imperative to expand outcomes beyond locomotor recovery and consider other complications plaguing the quality of life of patients with SCI. Interestingly, the SCI field predominately utilizes female rodents for basic science research which contrasts most other male-biased research fields. We discuss the unique caveats this creates to the translatability of preclinical research in the SCI field. We also review current clinical and preclinical data examining sex as biological variable in SCI. Further, we report how technical considerations such as housing, size, care management, and age, confound the interpretation of sex-specific effects in animal studies of SCI. We have uncovered novel findings regarding how age differentially affects mortality and injury-induced anemia in males and females after SCI, and further identified estrus cycle dysfunction in mice after injury. Emerging concepts underlying sexually dimorphic responses to therapy are also discussed. Through a combination of literature review and primary research observations we present a practical guide for considering and incorporating sex as biological variable in preclinical neurotrauma studies.
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Affiliation(s)
- Andrew N Stewart
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Steven M MacLean
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Arnold J Stromberg
- Department of Statistics, College of Arts and Sciences, University of Kentucky, Lexington, KY, United States
| | - Jessica P Whelan
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - William M Bailey
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - John C Gensel
- Department of Physiology, University of Kentucky, Lexington, KY, United States.,Spinal Cord and Brain Injury Research Center, College of Medicine, University of Kentucky, Lexington, KY, United States
| | - Melinda E Wilson
- Department of Physiology, University of Kentucky, Lexington, KY, United States
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Lau D, Dalle Ore CL, Tarapore PE, Huang M, Manley G, Singh V, Mummaneni PV, Beattie M, Bresnahan J, Ferguson AR, Talbott JF, Whetstone W, Dhall SS. Value of aggressive surgical and intensive care unit in elderly patients with traumatic spinal cord injury. Neurosurg Focus 2020; 46:E3. [PMID: 30835676 DOI: 10.3171/2018.12.focus18555] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/06/2018] [Indexed: 11/06/2022]
Abstract
OBJECTIVEThe elderly are a growing subpopulation within traumatic spinal cord injury (SCI) patients. Studies have reported high morbidity and mortality rates in elderly patients who undergo surgery for SCI. In this study, the authors compare the perioperative outcomes of surgically managed elderly SCI patients with those of a younger cohort and those reported in the literature.METHODSData on a consecutive series of adult traumatic SCI patients surgically managed at a single institution in the period from 2007 to 2017 were retrospectively reviewed. The cohort was divided into two groups based on age: younger than 70 years and 70 years or older. Assessed outcomes included complications, in-hospital mortality, intensive care unit (ICU) stay, hospital length of stay (LOS), disposition, and neurological status.RESULTSA total of 106 patients were included in the study: 83 young and 23 elderly. The two groups were similar in terms of imaging features (cord hemorrhage and fracture), operative technique, and American Spinal Injury Association Impairment Scale (AIS) grade. The elderly had a significantly higher proportion of cervical SCIs (95.7% vs 71.1%, p = 0.047). There were no significant differences between the young and the elderly in terms of the ICU stay (13.1 vs 13.3 days, respectively, p = 0.948) and hospital LOS (23.3 vs 21.7 days, p = 0.793). Elderly patients experienced significantly higher complication (73.9% vs 43.4%, p = 0.010) and mortality (13.0% vs 1.2%, p = 0.008) rates; in other words, the elderly patients had 1.7 times and 10.8 times the rate of complications and mortality, respectively, than the younger patients. No elderly patients were discharged home (0.0% vs 18.1%, p = 0.029). Discharge AIS grade and AIS grade change were similar between the groups.CONCLUSIONSElderly patients had higher complication and mortality rates than those in younger patients and were less likely to be discharged home. However, it does seem that mortality rates have improved compared to those in prior historical reports.
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Affiliation(s)
| | | | - Phiroz E Tarapore
- Departments of1Neurological Surgery.,2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
| | - Michael Huang
- Departments of1Neurological Surgery.,2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
| | | | - Vineeta Singh
- 2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California.,4Neurology
| | | | - Michael Beattie
- 2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
| | - Jacqueline Bresnahan
- 2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
| | - Adam R Ferguson
- 2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
| | - Jason F Talbott
- 2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California.,5Radiology, and
| | - William Whetstone
- 3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California.,6Emergency Medicine
| | - Sanjay S Dhall
- Departments of1Neurological Surgery.,2San Francisco General Hospital; and.,3TRACK-SCI, Brain and Spinal Injury Center, San Francisco General Hospital, University of California, San Francisco, California
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26
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Sutherland TC, Geoffroy CG. The Influence of Neuron-Extrinsic Factors and Aging on Injury Progression and Axonal Repair in the Central Nervous System. Front Cell Dev Biol 2020; 8:190. [PMID: 32269994 PMCID: PMC7109259 DOI: 10.3389/fcell.2020.00190] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 03/06/2020] [Indexed: 12/21/2022] Open
Abstract
In the aging western population, the average age of incidence for spinal cord injury (SCI) has increased, as has the length of survival of SCI patients. This places great importance on understanding SCI in middle-aged and aging patients. Axon regeneration after injury is an area of study that has received substantial attention and made important experimental progress, however, our understanding of how aging affects this process, and any therapeutic effort to modulate repair, is incomplete. The growth and regeneration of axons is mediated by both neuron intrinsic and extrinsic factors. In this review we explore some of the key extrinsic influences on axon regeneration in the literature, focusing on inflammation and astrogliosis, other cellular responses, components of the extracellular matrix, and myelin proteins. We will describe how each element supports the contention that axonal growth after injury in the central nervous system shows an age-dependent decline, and how this may affect outcomes after a SCI.
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Affiliation(s)
- Theresa C Sutherland
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, United States
| | - Cédric G Geoffroy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M Health Science Center, Bryan, TX, United States
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27
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Niu S, Ni Y, Niu T, Gao J. Knockdown PEG10 deteriorates H2O2-injury of PC-12 cells by targeting miR-34a-5p/TLX. Mol Immunol 2020; 118:1-8. [DOI: 10.1016/j.molimm.2019.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 08/16/2019] [Accepted: 11/27/2019] [Indexed: 12/25/2022]
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Abstract
Permanent disabilities following CNS injuries result from the failure of injured axons to regenerate and rebuild functional connections with their original targets. By contrast, injury to peripheral nerves is followed by robust regeneration, which can lead to recovery of sensory and motor functions. This regenerative response requires the induction of widespread transcriptional and epigenetic changes in injured neurons. Considerable progress has been made in recent years in understanding how peripheral axon injury elicits these widespread changes through the coordinated actions of transcription factors, epigenetic modifiers and, to a lesser extent, microRNAs. Although many questions remain about the interplay between these mechanisms, these new findings provide important insights into the pivotal role of coordinated gene expression and chromatin remodelling in the neuronal response to injury.
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Affiliation(s)
- Marcus Mahar
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA
| | - Valeria Cavalli
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA.
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29
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Hilton BJ, Blanquie O, Tedeschi A, Bradke F. High-resolution 3D imaging and analysis of axon regeneration in unsectioned spinal cord with or without tissue clearing. Nat Protoc 2019; 14:1235-1260. [DOI: 10.1038/s41596-019-0140-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
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30
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Abstract
How the nervous system is wired has been a central question of neuroscience since the inception of the field, and many of the foundational discoveries and conceptual advances have been made through the study of invertebrate experimental organisms, including Caenorhabditis elegans and Drosophila melanogaster. Although many guidance molecules and receptors have been identified, recent experiments have shed light on the many modes of action for these pathways. Here, we summarize the recent progress in determining how the physical and temporal constraints of the surrounding environment provide instructive regulations in nervous system wiring. We use Netrin and its receptors as an example to analyze the complexity of how they guide neurite outgrowth. In neurite repair, conserved injury detection and response-signaling pathways regulate gene expression and cytoskeletal dynamics. We also describe recent developments in the research on molecular mechanisms of neurite regeneration in worms and flies.
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Affiliation(s)
- Claire E Richardson
- Department of Biology, Stanford University, Stanford, California 94305, USA;
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California 94305, USA; .,Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
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31
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Stewart AN, Gensel JC, Zhang B. Therapeutic implications of advanced age at time of spinal cord injury. Neural Regen Res 2019; 14:1895-1896. [PMID: 31290439 PMCID: PMC6676888 DOI: 10.4103/1673-5374.259606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Andrew N Stewart
- Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - John C Gensel
- Spinal Cord and Brain Injury Research Center, Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Bei Zhang
- College of Public Health, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, China
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32
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Hao M, Ji XR, Chen H, Zhang W, Zhang LC, Zhang LH, Tang PF, Lu N. Cell cycle and complement inhibitors may be specific for treatment of spinal cord injury in aged and young mice: Transcriptomic analyses. Neural Regen Res 2018; 13:518-527. [PMID: 29623939 PMCID: PMC5900517 DOI: 10.4103/1673-5374.226405] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Previous studies have reported age-specific pathological and functional outcomes in young and aged patients suffering spinal cord injury, but the mechanisms remain poorly understood. In this study, we examined mice with spinal cord injury. Gene expression profiles from the Gene Expression Omnibus database (accession number GSE93561) were used, including spinal cord samples from 3 young injured mice (2-3-months old, induced by Impactor at Th9 level) and 3 control mice (2-3-months old, no treatment), as well as 2 aged injured mice (15-18-months old, induced by Impactor at Th9 level) and 2 control mice (15-18-months old, no treatment). Differentially expressed genes (DEGs) in spinal cord tissue from injured and control mice were identified using the Linear Models for Microarray data method, with a threshold of adjusted P < 0.05 and |logFC(fold change)| > 1.5. Protein-protein interaction networks were constructed using data from the STRING database, followed by module analysis by Cytoscape software to screen crucial genes. Kyoto encyclopedia of genes and genomes pathway and Gene Ontology enrichment analyses were performed to investigate the underlying functions of DEGs using Database for Annotation, Visualization and Integrated Discovery. Consequently, 1,604 and 1,153 DEGs were identified between injured and normal control mice in spinal cord tissue of aged and young mice, respectively. Furthermore, a Venn diagram showed that 960 DEGs were shared among aged and young mice, while 644 and 193 DEGs were specific to aged and young mice, respectively. Functional enrichment indicates that shared DEGs are involved in osteoclast differentiation, extracellular matrix-receptor interaction, nuclear factor-kappa B signaling pathway, and focal adhesion. Unique genes for aged and young injured groups were involved in the cell cycle (upregulation of PLK1) and complement (upregulation of C3) activation, respectively. These findings were confirmed by functional analysis of genes in modules (common, 4; aged, 2; young, 1) screened from protein-protein interaction networks. Accordingly, cell cycle and complement inhibitors may be specific treatments for spinal cord injury in aged and young mice, respectively.
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Affiliation(s)
- Ming Hao
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Xin-Ran Ji
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Hua Chen
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Wei Zhang
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Li-Cheng Zhang
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Li-Hai Zhang
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Pei-Fu Tang
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
| | - Ning Lu
- Department of Orthopedic Surgery, General Hospital of People's Liberation Army (301 Hospital), Beijing, China
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Shin JE, Cho Y. Epigenetic Regulation of Axon Regeneration after Neural Injury. Mol Cells 2017; 40:10-16. [PMID: 28152303 PMCID: PMC5303884 DOI: 10.14348/molcells.2017.2311] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 01/16/2017] [Accepted: 01/23/2017] [Indexed: 12/16/2022] Open
Abstract
When peripheral axons are damaged, neuronal injury signaling pathways induce transcriptional changes that support axon regeneration and consequent functional recovery. The recent development of bioinformatics techniques has allowed for the identification of many of the regeneration-associated genes that are regulated by neural injury, yet it remains unclear how global changes in transcriptome are coordinated. In this article, we review recent studies on the epigenetic mechanisms orchestrating changes in gene expression in response to nerve injury. We highlight the importance of epigenetic mechanisms in discriminating efficient axon regeneration in the peripheral nervous system and very limited axon regrowth in the central nervous system and discuss the therapeutic potential of targeting epigenetic regulators to improve neural recovery.
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Affiliation(s)
- Jung Eun Shin
- The Research Institute of Basic Sciences, Seoul National University, Seoul 08826,
Korea
| | - Yongcheol Cho
- Department of Life Sciences, Korea University, Seoul 02841,
Korea
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