1
|
Saijilafu, Ye LC, Zhang JY, Xu RJ. The top 100 most cited articles on axon regeneration from 2003 to 2023: a bibliometric analysis. Front Neurosci 2024; 18:1410988. [PMID: 38988773 PMCID: PMC11233811 DOI: 10.3389/fnins.2024.1410988] [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: 04/02/2024] [Accepted: 06/04/2024] [Indexed: 07/12/2024] Open
Abstract
Objective In this study, we used a bibliometric and visual analysis to evaluate the characteristics of the 100 most cited articles on axon regeneration. Methods The 100 most cited papers on axon regeneration published between 2003 and 2023 were identified by searching the Web of Science Core Collection database. The extracted data included the title, author, keywords, journal, publication year, country, and institution. A bibliometric analysis was subsequently undertaken. Results The examined set of 100 papers collectively accumulated a total of 39,548 citations. The number of citations for each of the top 100 articles ranged from 215 to 1,604, with a median value of 326. The author with the most contributions to this collection was He, Zhigang, having authored eight papers. Most articles originated in the United States (n = 72), while Harvard University was the institution with the most cited manuscripts (n = 19). Keyword analysis unveiled several research hotspots, such as chondroitin sulfate proteoglycan, alternative activation, exosome, Schwann cells, axonal protein synthesis, electrical stimulation, therapeutic factors, and remyelination. Examination of keywords in the articles indicated that the most recent prominent keyword was "local delivery." Conclusion This study offers bibliometric insights into axon regeneration, underscoring that the United States is a prominent leader in this field. Our analysis highlights the growing relevance of local delivery systems in axon regeneration. Although these systems have shown promise in preclinical models, challenges associated with long-term optimization, agent selection, and clinical translation remain. Nevertheless, the continued development of local delivery technologies represents a promising pathway for achieving axon regeneration; however, additional research is essential to fully realize their potential and thereby enhance patient outcomes.
Collapse
Affiliation(s)
- Saijilafu
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, China
| | - Ling-Chen Ye
- Department of Orthopaedics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Jing-Yu Zhang
- Department of Orthopaedics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| | - Ren-Jie Xu
- Department of Orthopaedics, Suzhou Municipal Hospital, The Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou, China
| |
Collapse
|
2
|
Zhao H, Zong X, Li L, Li N, Liu C, Zhang W, Li J, Yang C, Huang S. Electroacupuncture Inhibits Neuroinflammation Induced by Astrocytic Necroptosis Through RIP1/MLKL/TLR4 Pathway in a Mouse Model of Spinal Cord Injury. Mol Neurobiol 2024; 61:3258-3271. [PMID: 37982922 DOI: 10.1007/s12035-023-03650-y] [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: 05/19/2023] [Accepted: 09/08/2023] [Indexed: 11/21/2023]
Abstract
Astrocytic necroptosis plays an essential role in the progression and regression of neurological disorders, which contributes to the neuroinflammation and disrupts neuronal regeneration and remyelination of severed axons. Electroacupuncture (EA), an effective therapeutic efficacy against spinal cord injury (SCI), has been proved to reduce neuronal cell apoptosis, inhibit inflammation, and prompt neural stem cell proliferation and differentiations. However, there have been few reports on whether EA regulate astrocytic necroptosis in SCI model. To investigate the effects of EA on astrocytic necroptosis and the mechanisms involved in the inhibition of astrocytic necroptosis after SCI in mice by EA, 8-week-old female C57BL/6 mice were subjected to SCI surgery and randomly divided into EA and SCI groups. Mice receiving sham surgery were included as sham group. "Jiaji" was selected as points for EA treatment, 10 min/day for 14 days. The in vitro data revealed that EA treatment significantly improved the nervous function and pathological changes after SCI. EA also reduced the number of GFAP/P-MLKL, GFAP/MLKL, GFAP/HMGB1, and Iba1/HMGB1 co-positive cells and inhibited the expressions of IL-6, IL-1β, and IL-33. The results indicate a significant reduction in inflammatory reaction and astrocytic necroptosis in mice with SCI by EA. Additionally, the expressions of RIP1, MLKL, and TLR4, which are associated with necroptosis, were found to be downregulated by EA. In this study, we confirmed that EA can inhibit neuroinflammation by reducing astrocytic necroptosis through downregulation of RIP1/MLKL/TLR4 pathway in mice with SCI.
Collapse
Affiliation(s)
- Hongdi Zhao
- Chongqing Medical University, Chongqing, 400016, China
- Affiliated Hospital of Chifeng University, Inner Mongolia Autonomous Region, Chifeng, 024099, China
| | - Xiaoqin Zong
- Chongqing Medical University, Chongqing, 400016, China
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Long Li
- Chongqing Medical University, Chongqing, 400016, China
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Na Li
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Chunlei Liu
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Wanchao Zhang
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Juan Li
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China
| | - Cheng Yang
- Chongqing Medical University, Chongqing, 400016, China.
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China.
| | - Siqin Huang
- Chongqing Medical University, Chongqing, 400016, China.
- Chongqing College of Traditional Chinese Medicine, Chongqing, 402760, China.
| |
Collapse
|
3
|
Kvistad CE, Kråkenes T, Gavasso S, Bø L. Neural regeneration in the human central nervous system-from understanding the underlying mechanisms to developing treatments. Where do we stand today? Front Neurol 2024; 15:1398089. [PMID: 38803647 PMCID: PMC11129638 DOI: 10.3389/fneur.2024.1398089] [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: 03/08/2024] [Accepted: 04/22/2024] [Indexed: 05/29/2024] Open
Abstract
Mature neurons in the human central nervous system (CNS) fail to regenerate after injuries. This is a common denominator across different aetiologies, including multiple sclerosis, spinal cord injury and ischemic stroke. The lack of regeneration leads to permanent functional deficits with a substantial impact on patient quality of life, representing a significant socioeconomic burden worldwide. Great efforts have been made to decipher the responsible mechanisms and we now know that potent intra- and extracellular barriers prevent axonal repair. This knowledge has resulted in numerous clinical trials, aiming to promote neuroregeneration through different approaches. Here, we summarize the current understanding of the causes to the poor regeneration within the human CNS. We also review the results of the treatment attempts that have been translated into clinical trials so far.
Collapse
Affiliation(s)
| | - Torbjørn Kråkenes
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Sonia Gavasso
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Lars Bø
- Neuro-SysMed, Department of Neurology, Haukeland University Hospital, Bergen, Norway
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| |
Collapse
|
4
|
Yu H, Liu Z, Pang M, Luo Q, Huang C, He W, Liu B, Rong L. Wallerian Degeneration Assessed by Multi-Modal Magnetic Resonance Imaging of Cervical Spinal Cord Is Associated With Neurological Impairment After Spinal Cord Injury. J Neurotrauma 2024; 41:1240-1252. [PMID: 38204213 DOI: 10.1089/neu.2023.0305] [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: 01/12/2024] Open
Abstract
While Wallerian degeneration (WD) is a crucial pathological process induced with spinal cord injury (SCI), its underlying mechanisms is still understudied. In this study, we aim to assess structural alterations and clinical significance of WD in the cervical cord following SCI using multi-modal magnetic resonance imaging (MRI), which combines T2*-weighted imaging and diffusion tensor imaging (DTI). T2*-weighted images allow segmentation of anatomical structures and the detection of WD on macrostructural level. DTI, on the other hand, can identify the reduction in neuroaxonal integrity by measuring the diffusion of water molecules on the microstructural level. In this prospective study, 35 SCI patients (19 paraplegic and 16 tetraplegic patients) and 12 healthy controls were recruited between July 2020 and May 2022. The hyperintensity voxels in the dorsal column was manually labeled as WD on T2*-weighted images. The mean cross-sectional area (CSA) and mean DTI indexes of WD at the C2 level were calculated and compared between groups. Correlation analysis was used to determine the associations of the magnitude of WD with lesion characteristics and clinical outcomes. Compared with controls, SCI patients showed evident hyperintensity (35/35) and decreased neuroaxonal integrity (p < 0.05) within the dorsal column at the C2 level. A higher neurological level of injury was associated with a larger mean CSA and reduction in neuroaxonal integrity within WD (p < 0.05). Smaller total and dorsal tissue bridges were related to greater mean CSA and lower fractional anisotropy values in WD (p < 0.05), respectively. Moreover, SCI participants with significantly larger CSAs and significantly lower microstructural integrity had worse sensory outcomes (p < 0.05). This comprehensive evaluation of WD can help us better understand the mechanisms of WD, monitor progression, and assess the effectiveness of therapeutic interventions after SCI.
Collapse
Affiliation(s)
- Haiyang Yu
- Department of Spine Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of Orthopedics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Zhenzhen Liu
- Department of Radiology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Mao Pang
- Department of Spine Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, Guangdong, China
| | - Qiuxia Luo
- Department of Radiology, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chong Huang
- Department of Spine Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Weijie He
- Department of Orthopedics, Dongguan Hospital of Guangzhou University of Chinese Medicine, Dongguan, Guangdong, China
| | - Bin Liu
- Department of Spine Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, Guangdong, China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, Guangdong, China
| | - Limin Rong
- Department of Spine Surgery, Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Provincial Center for Engineering and Technology Research of Minimally Invasive Spine Surgery, Guangzhou, Guangdong, China
- Guangdong Provincial Center for Quality Control of Minimally Invasive Spine Surgery, Guangzhou, Guangdong, China
| |
Collapse
|
5
|
DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-leucine zipper kinase (DLK) to nocodazole: Evidence for a homeostatic cytoskeletal repair mechanism. PLoS One 2024; 19:e0300539. [PMID: 38574058 PMCID: PMC10994325 DOI: 10.1371/journal.pone.0300539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 02/28/2024] [Indexed: 04/06/2024] Open
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that low dose nocodazole treatment activates DLK signaling. Activation of DLK signaling results in a DLK-dependent transcriptional signature, which we identify through RNA-seq. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes. We identify alterations to the cytoskeleton including actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
Collapse
Affiliation(s)
- Laura DeVault
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Chase Mateusiak
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - John Palucki
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Michael Brent
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Computer Science & Engineering, Washington University, St. Louis, MO, United States of America
| | - Jeffrey Milbrandt
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Needleman Center for Neurometabolism and Axonal Therapeutics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| |
Collapse
|
6
|
Hashimoto S, Nagoshi N, Nakamura M, Okano H. Regenerative medicine strategies for chronic complete spinal cord injury. Neural Regen Res 2024; 19:818-824. [PMID: 37843217 PMCID: PMC10664101 DOI: 10.4103/1673-5374.382230] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/30/2023] [Accepted: 06/27/2023] [Indexed: 10/17/2023] Open
Abstract
Spinal cord injury is a condition in which the parenchyma of the spinal cord is damaged by trauma or various diseases. While rapid progress has been made in regenerative medicine for spinal cord injury that was previously untreatable, most research in this field has focused on the early phase of incomplete injury. However, the majority of patients have chronic severe injuries; therefore, treatments for these situations are of fundamental importance. The reason why the treatment of complete spinal cord injury has not been studied is that, unlike in the early stage of incomplete spinal cord injury, there are various inhibitors of neural regeneration. Thus, we assumed that it is difficult to address all conditions with a single treatment in chronic complete spinal cord injury and that a combination of several treatments is essential to target severe pathologies. First, we established a combination therapy of cell transplantation and drug-releasing scaffolds, which contributes to functional recovery after chronic complete transection spinal cord injury, but we found that functional recovery was limited and still needs further investigation. Here, for the further development of the treatment of chronic complete spinal cord injury, we review the necessary approaches to the different pathologies based on our findings and the many studies that have been accumulated to date and discuss, with reference to the literature, which combination of treatments is most effective in achieving functional recovery.
Collapse
Affiliation(s)
- Shogo Hashimoto
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Narihito Nagoshi
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Masaya Nakamura
- Department of Orthopedic Surgery, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| |
Collapse
|
7
|
Deng J, Sun C, Zheng Y, Gao J, Cui X, Wang Y, Zhang L, Tang P. In vivo imaging of the neuronal response to spinal cord injury: a narrative review. Neural Regen Res 2024; 19:811-817. [PMID: 37843216 PMCID: PMC10664102 DOI: 10.4103/1673-5374.382225] [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: 01/07/2023] [Revised: 05/15/2023] [Accepted: 07/07/2023] [Indexed: 10/17/2023] Open
Abstract
Deciphering the neuronal response to injury in the spinal cord is essential for exploring treatment strategies for spinal cord injury (SCI). However, this subject has been neglected in part because appropriate tools are lacking. Emerging in vivo imaging and labeling methods offer great potential for observing dynamic neural processes in the central nervous system in conditions of health and disease. This review first discusses in vivo imaging of the mouse spinal cord with a focus on the latest imaging techniques, and then analyzes the dynamic biological response of spinal cord sensory and motor neurons to SCI. We then summarize and compare the techniques behind these studies and clarify the advantages of in vivo imaging compared with traditional neuroscience examinations. Finally, we identify the challenges and possible solutions for spinal cord neuron imaging.
Collapse
Affiliation(s)
- Junhao Deng
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Chang Sun
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
- Department of Orthopedics, Air Force Medical Center, PLA, Beijing, China
| | - Ying Zheng
- Medical School of Chinese PLA, Beijing, China
| | - Jianpeng Gao
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Xiang Cui
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Yu Wang
- Institute of Orthopedics, The First Medical Center, Chinese PLA General Hospital, Beijing, China
- Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Licheng Zhang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| | - Peifu Tang
- Department of Orthopedics, The Fourth Medical Center of Chinese PLA General Hospital, Beijing, China
- National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Beijing, China
| |
Collapse
|
8
|
Zedde M, Grisendi I, Assenza F, Napoli M, Moratti C, Di Cecco G, D’Aniello S, Valzania F, Pascarella R. Stroke-Induced Secondary Neurodegeneration of the Corticospinal Tract-Time Course and Mechanisms Underlying Signal Changes in Conventional and Advanced Magnetic Resonance Imaging. J Clin Med 2024; 13:1969. [PMID: 38610734 PMCID: PMC11012763 DOI: 10.3390/jcm13071969] [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: 02/22/2024] [Revised: 03/19/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
Secondary neurodegeneration refers to the final result of several simultaneous and sequential mechanisms leading to the loss of substance and function in brain regions connected to the site of a primary injury. Stroke is one of the most frequent primary injuries. Among the subtypes of post-stroke secondary neurodegeneration, axonal degeneration of the corticospinal tract, also known as Wallerian degeneration, is the most known, and it directly impacts motor functions, which is crucial for the motor outcome. The timing of its appearance in imaging studies is usually considered late (over 4 weeks), but some diffusion-based magnetic resonance imaging (MRI) techniques, as diffusion tensor imaging (DTI), might show alterations as early as within 7 days from the stroke. The different sequential pathological stages of secondary neurodegeneration provide an interpretation of the signal changes seen by MRI in accordance with the underlying mechanisms of axonal necrosis and repair. Depending on the employed MRI technique and on the timing of imaging, different rates and thresholds of Wallerian degeneration have been provided in the literature. In fact, three main pathological stages of Wallerian degeneration are recognizable-acute, subacute and chronic-and MRI might show different changes: respectively, hyperintensity on T2-weighted sequences with corresponding diffusion restriction (14-20 days after the injury), followed by transient hypointensity of the tract on T2-weighted sequences, and by hyperintensity and atrophy of the tract on T2-weighted sequences. This is the main reason why this review is focused on MRI signal changes underlying Wallerian degeneration. The identification of secondary neurodegeneration, and in particular Wallerian degeneration, has been proposed as a prognostic indicator for motor outcome after stroke. In this review, the main mechanisms and neuroimaging features of Wallerian degeneration in adults are addressed, focusing on the time and mechanisms of tissue damage underlying the signal changes in MRI.
Collapse
Affiliation(s)
- Marialuisa Zedde
- Neurology Unit, Stroke Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (I.G.); (F.A.); (F.V.)
| | - Ilaria Grisendi
- Neurology Unit, Stroke Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (I.G.); (F.A.); (F.V.)
| | - Federica Assenza
- Neurology Unit, Stroke Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (I.G.); (F.A.); (F.V.)
| | - Manuela Napoli
- Neuroradiology Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (M.N.); (C.M.); (G.D.C.); (S.D.); (R.P.)
| | - Claudio Moratti
- Neuroradiology Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (M.N.); (C.M.); (G.D.C.); (S.D.); (R.P.)
| | - Giovanna Di Cecco
- Neuroradiology Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (M.N.); (C.M.); (G.D.C.); (S.D.); (R.P.)
| | - Serena D’Aniello
- Neuroradiology Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (M.N.); (C.M.); (G.D.C.); (S.D.); (R.P.)
| | - Franco Valzania
- Neurology Unit, Stroke Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (I.G.); (F.A.); (F.V.)
| | - Rosario Pascarella
- Neuroradiology Unit, Azienda Unità Sanitaria Locale-IRCCS di Reggio Emilia, Viale Risorgimento 80, 42123 Reggio Emilia, Italy; (M.N.); (C.M.); (G.D.C.); (S.D.); (R.P.)
| |
Collapse
|
9
|
DeVault L, Mateusiak C, Palucki J, Brent M, Milbrandt J, DiAntonio A. The response of Dual-Leucine Zipper Kinase (DLK) to nocodazole: evidence for a homeostatic cytoskeletal repair mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.06.561227. [PMID: 37873434 PMCID: PMC10592635 DOI: 10.1101/2023.10.06.561227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Genetic and pharmacological perturbation of the cytoskeleton enhances the regenerative potential of neurons. This response requires Dual-leucine Zipper Kinase (DLK), a neuronal stress sensor that is a central regulator of axon regeneration and degeneration. The damage and repair aspects of this response are reminiscent of other cellular homeostatic systems, suggesting that a cytoskeletal homeostatic response exists. In this study, we propose a framework for understanding DLK mediated neuronal cytoskeletal homeostasis. We demonstrate that a) low dose nocodazole treatment activates DLK signaling and b) DLK signaling mitigates the microtubule damage caused by the cytoskeletal perturbation. We also perform RNA-seq to discover a DLK-dependent transcriptional signature. This signature includes genes likely to attenuate DLK signaling while simultaneously inducing actin regulating genes and promoting actin-based morphological changes to the axon. These results are consistent with the model that cytoskeletal disruption in the neuron induces a DLK-dependent homeostatic mechanism, which we term the Cytoskeletal Stress Response (CSR) pathway.
Collapse
|
10
|
Jeon Y, Shin YK, Kim H, Choi YY, Kang M, Kwon Y, Cho Y, Chi SW, Shin JE. βPix Guanine Nucleotide Exchange Factor Regulates Regeneration of Injured Peripheral Axons. Int J Mol Sci 2023; 24:14357. [PMID: 37762659 PMCID: PMC10532151 DOI: 10.3390/ijms241814357] [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: 07/29/2023] [Revised: 09/13/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Axon regeneration is essential for successful recovery after peripheral nerve injury. Although growth cone reformation and axonal extension are crucial steps in axonal regeneration, the regulatory mechanisms underlying these dynamic processes are poorly understood. Here, we identify βPix (Arhgef7), the guanine nucleotide exchange factor for Rac1 GTPase, as a regulator of axonal regeneration. After sciatic nerve injury in mice, the expression levels of βPix increase significantly in nerve segments containing regenerating axons. In regrowing axons, βPix is localized in the peripheral domain of the growth cone. Using βPix neuronal isoform knockout (NIKO) mice in which the neuronal isoforms of βPix are specifically removed, we demonstrate that βPix promotes neurite outgrowth in cultured dorsal root ganglion neurons and in vivo axon regeneration after sciatic nerve crush injury. Activation of cJun and STAT3 in the cell bodies is not affected in βPix NIKO mice, supporting the local action of βPix in regenerating axons. Finally, inhibiting Src, a kinase previously identified as an activator of the βPix neuronal isoform, causes axon outgrowth defects in vitro, like those found in the βPix NIKO neurons. Altogether, these data indicate that βPix plays an important role in axonal regrowth during peripheral nerve regeneration.
Collapse
Affiliation(s)
- Yewon Jeon
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea;
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Yoon Kyung Shin
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Hwigyeong Kim
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
| | - Yun Young Choi
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
| | - Minjae Kang
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
| | - Younghee Kwon
- Department School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Yongcheol Cho
- Department of Brain Sciences, DGIST, Daegu 42899, Republic of Korea;
| | - Sung Wook Chi
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea;
| | - Jung Eun Shin
- Peripheral Neuropathy Research Center (PNRC), Department of Molecular Neuroscience, College of Medicine, Dong-A University, Busan 49201, Republic of Korea; (Y.K.S.); (H.K.); (Y.Y.C.); (M.K.)
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan 49201, Republic of Korea
| |
Collapse
|
11
|
Alexandris AS, Lee Y, Lehar M, Alam Z, McKenney J, Perdomo D, Ryu J, Welsbie D, Zack DJ, Koliatsos VE. Traumatic Axonal Injury in the Optic Nerve: The Selective Role of SARM1 in the Evolution of Distal Axonopathy. J Neurotrauma 2023; 40:1743-1761. [PMID: 36680758 PMCID: PMC10460965 DOI: 10.1089/neu.2022.0416] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Traumatic axonal injury (TAI), thought to be caused by rotational acceleration of the head, is a prevalent neuropathology in traumatic brain injury (TBI). TAI in the optic nerve is a common finding in multiple blunt-force TBI models and hence a great model to study mechanisms and treatments for TAI, especially in view of the compartmentalized anatomy of the visual system. We have previously shown that the somata and the proximal, but not distal, axons of retinal ganglion cells (RGC) respond to DLK/LZK blockade after impact acceleration of the head (IA-TBI). Here, we explored the role of the sterile alpha and TIR-motif containing 1 (SARM1), the key driver of Wallerian degeneration (WD), in the progressive breakdown of distal and proximal segments of the optic nerve following IA-TBI with high-resolution morphological and classical neuropathological approaches. Wild type and Sarm1 knockout (KO) mice received IA-TBI or sham injury and were allowed to survive for 3, 7, 14, and 21 days. Ultrastructural and microscopic analyses revealed that TAI in the optic nerve is characterized by variable involvement of individual axons, ranging from apparent early disconnection of a subpopulation of axons to a range of ongoing axonal and myelin perturbations. Traumatic axonal injury resulted in the degeneration of a population of axons distal and proximal to the injury, along with retrograde death of a subpopulation of RGCs. Quantitative analyses on proximal and distal axons and RGC somata revealed that different neuronal domains exhibit differential vulnerability, with distal axon segments showing more severe degeneration compared with proximal segments and RGC somata. Importantly, we found that Sarm1 KO had a profound effect in the distal optic nerve by suppressing axonal degeneration by up to 50% in the first 2 weeks after IA-TBI, with a continued but lower effect at 3 weeks, while also suppressing microglial activation. Sarm1 KO had no evident effect on the initial traumatic disconnection and did not ameliorate the proximal optic axonopathy or the subsequent attrition of RGCs, indicating that the fate of different axonal segments in the course of TAI may depend on distinct molecular programs within axons.
Collapse
Affiliation(s)
| | - Youngrim Lee
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mohamed Lehar
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zahra Alam
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - James McKenney
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Dianela Perdomo
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Jiwon Ryu
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Derek Welsbie
- Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, La Jolla, California, USA
| | - Donald J. Zack
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neuroscience Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Vassilis E. Koliatsos
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
12
|
Davleeva MA, Garifulin RR, Bashirov FV, Izmailov AA, Nurullin LF, Salafutdinov II, Gatina DZ, Shcherbinin DN, Lysenko AA, Tutykhina IL, Shmarov MM, Islamov RR. Molecular and cellular changes in the post-traumatic spinal cord remodeling after autoinfusion of a genetically-enriched leucoconcentrate in a mini-pig model. Neural Regen Res 2023; 18:1505-1511. [PMID: 36571355 PMCID: PMC10075125 DOI: 10.4103/1673-5374.360241] [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: 11/07/2022] Open
Abstract
Post-traumatic spinal cord remodeling includes both degenerating and regenerating processes, which affect the potency of the functional recovery after spinal cord injury (SCI). Gene therapy for spinal cord injury is proposed as a promising therapeutic strategy to induce positive changes in remodeling of the affected neural tissue. In our previous studies for delivering the therapeutic genes at the site of spinal cord injury, we developed a new approach using an autologous leucoconcentrate transduced ex vivo with chimeric adenoviruses (Ad5/35) carrying recombinant cDNA. In the present study, the efficacy of the intravenous infusion of an autologous genetically-enriched leucoconcentrate simultaneously producing recombinant vascular endothelial growth factor (VEGF), glial cell line-derived neurotrophic factor (GDNF), and neural cell adhesion molecule (NCAM) was evaluated with regard to the molecular and cellular changes in remodeling of the spinal cord tissue at the site of damage in a model of mini-pigs with moderate spinal cord injury. Experimental animals were randomly divided into two groups of 4 pigs each: the therapeutic (infused with the leucoconcentrate simultaneously transduced with a combination of the three chimeric adenoviral vectors Ad5/35-VEGF165, Ad5/35-GDNF, and Ad5/35-NCAM1) and control groups (infused with intact leucoconcentrate). The morphometric and immunofluorescence analysis of the spinal cord regeneration in the rostral and caudal segments according to the epicenter of the injury in the treated animals compared to the control mini-pigs showed: (1) higher sparing of the grey matter and increased survivability of the spinal cord cells (lower number of Caspase-3-positive cells and decreased expression of Hsp27); (2) recovery of synaptophysin expression; (3) prevention of astrogliosis (lower area of glial fibrillary acidic protein-positive astrocytes and ionized calcium binding adaptor molecule 1-positive microglial cells); (4) higher growth rates of regenerating βIII-tubulin-positive axons accompanied by a higher number of oligodendrocyte transcription factor 2-positive oligodendroglial cells in the lateral corticospinal tract region. These results revealed the efficacy of intravenous infusion of the autologous genetically-enriched leucoconcentrate producing recombinant VEGF, GDNF, and NCAM in the acute phase of spinal cord injury on the positive changes in the post-traumatic remodeling nervous tissue at the site of direct injury. Our data provide a solid platform for a new ex vivo gene therapy for spinal cord injury and will facilitate further translation of regenerative therapies in clinical neurology.
Collapse
Affiliation(s)
| | | | | | | | - Leniz Faritovich Nurullin
- Department of Histology, Cytology and Embryology, Kazan State Medical University; Kazan Institute of Biochemistry and Biophysics, Federal Research Center of Kazan Scientific Center of Russian Academy of Sciences, Kazan, Russia
| | - Ilnur Ildusovich Salafutdinov
- Department of Histology, Cytology and Embryology, Kazan State Medical University; Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Russia
| | | | - Dmitrij Nikolaevich Shcherbinin
- The National Research Center for Epidemiology and Microbiology named after Honorary Academician N.F. Gamaleya of the Ministry of Health of the Russian Federation, Moscow, Russia
| | - Andrei Aleksandrovich Lysenko
- The National Research Center for Epidemiology and Microbiology named after Honorary Academician N.F. Gamaleya of the Ministry of Health of the Russian Federation, Moscow, Russia
| | - Irina Leonidovna Tutykhina
- The National Research Center for Epidemiology and Microbiology named after Honorary Academician N.F. Gamaleya of the Ministry of Health of the Russian Federation, Moscow, Russia
| | - Maksim Mikhailovich Shmarov
- The National Research Center for Epidemiology and Microbiology named after Honorary Academician N.F. Gamaleya of the Ministry of Health of the Russian Federation, Moscow, Russia
| | | |
Collapse
|
13
|
Gupta S, Dutta S, Hui SP. Regenerative Potential of Injured Spinal Cord in the Light of Epigenetic Regulation and Modulation. Cells 2023; 12:1694. [PMID: 37443728 PMCID: PMC10341208 DOI: 10.3390/cells12131694] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/13/2023] [Accepted: 06/17/2023] [Indexed: 07/15/2023] Open
Abstract
A spinal cord injury is a form of physical harm imposed on the spinal cord that causes disability and, in many cases, leads to permanent mammalian paralysis, which causes a disastrous global issue. Because of its non-regenerative aspect, restoring the spinal cord's role remains one of the most daunting tasks. By comparison, the remarkable regenerative ability of some regeneration-competent species, such as some Urodeles (Axolotl), Xenopus, and some teleost fishes, enables maximum functional recovery, even after complete spinal cord transection. During the last two decades of intensive research, significant progress has been made in understanding both regenerative cells' origins and the molecular signaling mechanisms underlying the regeneration and reconstruction of damaged spinal cords in regenerating organisms and mammals, respectively. Epigenetic control has gradually moved into the center stage of this research field, which has been helped by comprehensive work demonstrating that DNA methylation, histone modifications, and microRNAs are important for the regeneration of the spinal cord. In this review, we concentrate primarily on providing a comparison of the epigenetic mechanisms in spinal cord injuries between non-regenerating and regenerating species. In addition, we further discuss the epigenetic mediators that underlie the development of a regeneration-permissive environment following injury in regeneration-competent animals and how such mediators may be implicated in optimizing treatment outcomes for spinal cord injurie in higher-order mammals. Finally, we briefly discuss the role of extracellular vesicles (EVs) in the context of spinal cord injury and their potential as targets for therapeutic intervention.
Collapse
Affiliation(s)
- Samudra Gupta
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
| | - Suman Dutta
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK;
| | - Subhra Prakash Hui
- S.N. Pradhan Centre for Neurosciences, University of Calcutta, 35, Ballygunge Circular Road, Kolkata 700019, India;
| |
Collapse
|
14
|
Varadarajan SG, Wang F, Dhande OS, Le P, Duan X, Huberman AD. Postsynaptic neuronal activity promotes regeneration of retinal axons. Cell Rep 2023; 42:112476. [PMID: 37141093 PMCID: PMC10247459 DOI: 10.1016/j.celrep.2023.112476] [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: 06/27/2022] [Revised: 11/02/2022] [Accepted: 04/19/2023] [Indexed: 05/05/2023] Open
Abstract
The wiring of visual circuits requires that retinal neurons functionally connect to specific brain targets, a process that involves activity-dependent signaling between retinal axons and their postsynaptic targets. Vision loss in various ophthalmological and neurological diseases is caused by damage to the connections from the eye to the brain. How postsynaptic brain targets influence retinal ganglion cell (RGC) axon regeneration and functional reconnection with the brain targets remains poorly understood. Here, we established a paradigm in which the enhancement of neural activity in the distal optic pathway, where the postsynaptic visual target neurons reside, promotes RGC axon regeneration and target reinnervation and leads to the rescue of optomotor function. Furthermore, selective activation of retinorecipient neuron subsets is sufficient to promote RGC axon regeneration. Our findings reveal a key role for postsynaptic neuronal activity in the repair of neural circuits and highlight the potential to restore damaged sensory inputs via proper brain stimulation.
Collapse
Affiliation(s)
- Supraja G Varadarajan
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA.
| | - Fei Wang
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA
| | - Onkar S Dhande
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Phung Le
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Xin Duan
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA, USA; Department of Physiology, University of California, San Francisco, San Francisco, CA, USA; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| | - Andrew D Huberman
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA; Department of Ophthalmology, Stanford University School of Medicine, Stanford, CA, USA; BioX, Stanford University School of Medicine, Stanford, CA, USA.
| |
Collapse
|
15
|
Ahanonu B, Crowther A, Kania A, Casillas MR, Basbaum A. Long-term optical imaging of the spinal cord in awake, behaving animals. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.22.541477. [PMID: 37292913 PMCID: PMC10245895 DOI: 10.1101/2023.05.22.541477] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Advances in optical imaging approaches and fluorescent biosensors have enabled an understanding of the spatiotemporal and long-term neural dynamics in the brain of awake animals. However, methodological difficulties and the persistence of post-laminectomy fibrosis have greatly limited similar advances in the spinal cord. To overcome these technical obstacles, we combined in vivo application of fluoropolymer membranes that inhibit fibrosis; a redesigned, cost-effective implantable spinal imaging chamber; and improved motion correction methods that together permit imaging of the spinal cord in awake, behaving mice, for months to over a year. We also demonstrate a robust ability to monitor axons, identify a spinal cord somatotopic map, conduct Ca2+ imaging of neural dynamics in behaving animals responding to pain-provoking stimuli, and observe persistent microglial changes after nerve injury. The ability to couple neural activity and behavior at the spinal cord level will drive insights not previously possible at a key location for somatosensory transmission to the brain.
Collapse
Affiliation(s)
- Biafra Ahanonu
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
- These authors contributed equally
| | - Andrew Crowther
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
- These authors contributed equally
| | - Artur Kania
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, QC, H2W 1R7, Canada
- Department of Cell Biology and Anatomy, and Division of Experimental Medicine, McGill University, Montréal, QC, H3A 2B2, Canada
| | - Mariela Rosa Casillas
- Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Allan Basbaum
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94158, USA
- Lead Contact
| |
Collapse
|
16
|
Clary RC, Jenkins BA, Lumpkin EA. Spatiotemporal dynamics of sensory neuron and Merkel-cell remodeling are decoupled during epidermal homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.14.528558. [PMID: 36824872 PMCID: PMC9949164 DOI: 10.1101/2023.02.14.528558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
As the juncture between the body and environment, epithelia are both protective barriers and sensory interfaces that continually renew. To determine whether sensory neurons remodel to maintain homeostasis, we used in vivo two-photon imaging of somatosensory axons innervating Merkel cells in adult mouse skin. These touch receptors were highly plastic: 63% of Merkel cells and 89% of branches appeared, disappeared, grew, regressed and/or relocated over a month. Interestingly, Merkel-cell plasticity was synchronized across arbors during rapid epithelial turnover. When Merkel cells remodeled, the degree of plasticity between Merkel-cell clusters and their axons was well correlated. Moreover, branches were stabilized by Merkel-cell contacts. These findings highlight the role of epithelial-neural crosstalk in homeostatic remodeling. Conversely, axons were also dynamic when Merkel cells were stable, indicating that intrinsic neural mechanisms drive branch plasticity. Two terminal morphologies innervated Merkel cells: transient swellings called boutons, and stable cups termed kylikes. In Atoh1 knockout mice that lack Merkel cells, axons showed higher complexity than control mice, with exuberant branching and no kylikes. Thus, Merkel cells limit axonal branching and promote branch maturation. Together, these results reveal a previously unsuspected high degree of plasticity in somatosensory axons that is biased, but not solely dictated, by plasticity of target epithelial cells. This system provides a platform to identify intrinsic and extrinsic mechanisms that govern axonal patterning in epithelial homeostasis.
Collapse
|
17
|
Herwerth M, Wyss M. Axon degeneration: new actor in an old play. Neural Regen Res 2023; 18:547-548. [DOI: 10.4103/1673-5374.350200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
18
|
Zille M, Palumbo A. Approaches to quantify axonal morphology for the analysis of axonal degeneration. Neural Regen Res 2023; 18:309-310. [PMID: 35900409 PMCID: PMC9396496 DOI: 10.4103/1673-5374.343904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
|
19
|
Sabet MF, Barman S, Beller M, Meuth SG, Melzer N, Aktas O, Goebels N, Prozorovski T. Myelinating Co-Culture as a Model to Study Anti-NMDAR Neurotoxicity. Int J Mol Sci 2022; 24:ijms24010248. [PMID: 36613687 PMCID: PMC9820503 DOI: 10.3390/ijms24010248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 12/06/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Anti-NMDA receptor (NMDAR) encephalitis is frequently associated with demyelinating disorders (e.g., multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein-associated disease (MOGAD)) with regard to clinical presentation, neuropathological and cerebrospinal fluid findings. Indeed, autoantibodies (AABs) against the GluN1 (NR1) subunit of the NMDAR diminish glutamatergic transmission in both neurons and oligodendrocytes, leading to a state of NMDAR hypofunction. Considering the vital role of oligodendroglial NMDAR signaling in neuron-glia communication and, in particular, in tightly regulated trophic support to neurons, the influence of GluN1 targeting on the physiology of myelinated axon may be of importance. We applied a myelinating spinal cord cell culture model that contains all major CNS cell types, to evaluate the effects of a patient-derived GluN1-specific monoclonal antibody (SSM5) on neuronal and myelin integrity. A non-brain reactive (12D7) antibody was used as the corresponding isotype control. We show that in cultures at the late stage of myelination, prolonged treatment with SSM5, but not 12D7, leads to neuronal damage. This is characterized by neurite blebbing and fragmentation, and a reduction in the number of myelinated axons. However, this significant toxic effect of SSM5 was not observed in earlier cultures at the beginning of myelination. Anti-GluN1 AABs induce neurodegenerative changes and associated myelin loss in myelinated spinal cord cultures. These findings may point to the higher vulnerability of myelinated neurons towards interference in glutamatergic communication, and may refer to the disturbance of the NMDAR-mediated oligodendrocyte metabolic supply. Our work contributes to the understanding of the emerging association of NMDAR encephalitis with demyelinating disorders.
Collapse
Affiliation(s)
- Mercedeh Farhat Sabet
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Sumanta Barman
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Mathias Beller
- Institut für Mathematische Modellierung Biologischer Systeme, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Sven G. Meuth
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Nico Melzer
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Orhan Aktas
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - Norbert Goebels
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- Correspondence: (N.G.); (T.P.); Tel.: +49-211-81-04594 (N.G.); +49-211-81-05146 (T.P.)
| | - Tim Prozorovski
- Department of Neurology, Medical Faculty, Heinrich-Heine-Universität Düsseldorf, 40225 Düsseldorf, Germany
- Correspondence: (N.G.); (T.P.); Tel.: +49-211-81-04594 (N.G.); +49-211-81-05146 (T.P.)
| |
Collapse
|
20
|
Lima R, Monteiro A, Salgado AJ, Monteiro S, Silva NA. Pathophysiology and Therapeutic Approaches for Spinal Cord Injury. Int J Mol Sci 2022; 23:ijms232213833. [PMID: 36430308 PMCID: PMC9698625 DOI: 10.3390/ijms232213833] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 11/07/2022] [Indexed: 11/12/2022] Open
Abstract
Spinal cord injury (SCI) is a disabling condition that disrupts motor, sensory, and autonomic functions. Despite extensive research in the last decades, SCI continues to be a global health priority affecting thousands of individuals every year. The lack of effective therapeutic strategies for patients with SCI reflects its complex pathophysiology that leads to the point of no return in its function repair and regeneration capacity. Recently, however, several studies started to uncover the intricate network of mechanisms involved in SCI leading to the development of new therapeutic approaches. In this work, we present a detailed description of the physiology and anatomy of the spinal cord and the pathophysiology of SCI. Additionally, we provide an overview of different molecular strategies that demonstrate promising potential in the modulation of the secondary injury events that promote neuroprotection or neuroregeneration. We also briefly discuss other emerging therapies, including cell-based therapies, biomaterials, and epidural electric stimulation. A successful therapy might target different pathologic events to control the progression of secondary damage of SCI and promote regeneration leading to functional recovery.
Collapse
Affiliation(s)
- Rui Lima
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Andreia Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - António J. Salgado
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Susana Monteiro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
| | - Nuno A. Silva
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, 4710-057 Braga, Portugal
- ICVS/3B’s Associate Laboratory, PT Government Associated Laboratory, 4806-909 Braga/Guimarães, Portugal
- Correspondence:
| |
Collapse
|
21
|
Roldan CJ, Huh B, Song J, Nieto Y, Osei J, Chai T, Nouri K, Koyyalagunta L, Bruera E. Methylene blue for intractable pain from oral mucositis related to cancer treatment: a randomized phase 2 clinical trial. BMC Med 2022; 20:377. [PMID: 36324139 PMCID: PMC9632023 DOI: 10.1186/s12916-022-02579-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 09/26/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Oral mucositis (OM) in patients receiving cancer therapy is thus far not well managed with standard approaches. We aimed to assess the safety and effectiveness of methylene blue (MB) oral rinse for OM pain in patients receiving cancer therapy. METHODS In this randomized, single-blind phase 2 clinical trial, patients were randomized to one of four arms: MB 0.025%+conventional therapy (CTx) (n = 15), MB 0.05%+CTx (n = 14), MB 0.1%+CTx (n = 15), or CTx alone (n = 16). Intervention groups received MB oral rinse every 6 h for 2 days with outcomes measured at days 1-2; safety was evaluated up to 30 days. The primary outcome measured change in the pain numeric rating scale (0-10) from baseline to day 2. Secondary outcome measured change in oral function burden scores from baseline to day 2, World Health Organization OM grades, morphine equivalent daily doses, and adverse events. The trial was registered with ClinicalTrials.gov ID: NCT03469284. RESULTS Sixty patients (mean age 43, range 22-62 years) completed the study. Compared with those who received CTx alone, those who received MB had a significant reduction of pain scores at day 2 of treatment (mean ± SD); 0.025%: 5.2 ± 2.9, 0.05%: 4.5 ± 2.9, 0.1%: 5.15 ± 2.6) and reduction of oral function burden scores (0.025%: 2.5 ± 1.55, 0.05%: 2.8 ± 1.7, 0.1%: 2.9 ± 1.60). No serious adverse events were noted, but eight patients reported burning sensation of the oral cavity with the first dose, and this caused one patient to discontinue therapy. CONCLUSIONS MB oral rinse showed significant pain reduction and improved oral functioning with minimal adverse effects. TRIAL REGISTRATION ClinicalTrials.gov ID: NCT03469284.
Collapse
Affiliation(s)
- Carlos J Roldan
- Department of Pain Medicine, Unit 409, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA. .,McGovern Medical School at the University of Texas Health Science Center at Houston (UT Health), Houston, TX, USA.
| | - Billy Huh
- Department of Pain Medicine, Unit 409, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA
| | - Juhee Song
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yago Nieto
- Department of Stem Cell Transplant, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Joyce Osei
- The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Thomas Chai
- Department of Pain Medicine, Unit 409, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA
| | - Kent Nouri
- Department of Pain Medicine, Unit 409, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA
| | - Lakshmi Koyyalagunta
- Department of Pain Medicine, Unit 409, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX, 77030, USA
| | - Eduardo Bruera
- Department of Palliative, Rehabilitation, and Integrative Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| |
Collapse
|
22
|
Deck M, Van Hameren G, Campbell G, Bernard-Marissal N, Devaux J, Berthelot J, Lattard A, Médard JJ, Gautier B, Guelfi S, Abbou S, Quintana P, Chao de la Barca JM, Reynier P, Lenaers G, Chrast R, Tricaud N. Physiology of PNS axons relies on glycolytic metabolism in myelinating Schwann cells. PLoS One 2022; 17:e0272097. [PMID: 36194565 PMCID: PMC9531822 DOI: 10.1371/journal.pone.0272097] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 07/12/2022] [Indexed: 11/18/2022] Open
Abstract
While lactate shuttle theory states that glial cells metabolize glucose into lactate to shuttle it to neurons, how glial cells support axonal metabolism and function remains unclear. Lactate production is a common occurrence following anaerobic glycolysis in muscles. However, several other cell types, including some stem cells, activated macrophages and tumor cells, can produce lactate in presence of oxygen and cellular respiration, using Pyruvate Kinase 2 (PKM2) to divert pyruvate to lactate dehydrogenase. We show here that PKM2 is also upregulated in myelinating Schwann cells (mSC) of mature mouse sciatic nerve versus postnatal immature nerve. Deletion of this isoform in PLP-expressing cells in mice leads to a deficit of lactate in mSC and in peripheral nerves. While the structure of myelin sheath was preserved, mutant mice developed a peripheral neuropathy. Peripheral nerve axons of mutant mice failed to maintain lactate homeostasis upon activity, resulting in an impaired production of mitochondrial ATP. Action potential propagation was not altered but axonal mitochondria transport was slowed down, muscle axon terminals retracted and motor neurons displayed cellular stress. Additional reduction of lactate availability through dichloroacetate treatment, which diverts pyruvate to mitochondrial oxidative phosphorylation, further aggravated motor dysfunction in mutant mice. Thus, lactate production through PKM2 enzyme and aerobic glycolysis is essential in mSC for the long-term maintenance of peripheral nerve axon physiology and function.
Collapse
Affiliation(s)
- Marie Deck
- INM, INSERM, Université de Montpellier, Montpellier, France
- * E-mail: (NT); (MD)
| | | | | | | | - Jérôme Devaux
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jade Berthelot
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Alise Lattard
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jean-Jacques Médard
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Benoît Gautier
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Sophie Guelfi
- INM, INSERM, Université de Montpellier, Montpellier, France
| | | | | | - Juan Manuel Chao de la Barca
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Pascal Reynier
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Guy Lenaers
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Roman Chrast
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Nicolas Tricaud
- I-Stem, UEVE/UPS U861, INSERM, AFM, Corbeil-Essonnes, France
- * E-mail: (NT); (MD)
| |
Collapse
|
23
|
Liu T, Zhu W, Zhang X, He C, Liu X, Xin Q, Chen K, Wang H. Recent Advances in Cell and Functional Biomaterial Treatment for Spinal Cord Injury. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5079153. [PMID: 35978649 PMCID: PMC9377911 DOI: 10.1155/2022/5079153] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/17/2022] [Accepted: 07/25/2022] [Indexed: 12/17/2022]
Abstract
Spinal cord injury (SCI) is a devastating central nervous system disease caused by accidental events, resulting in loss of sensory and motor function. Considering the multiple effects of primary and secondary injuries after spinal cord injury, including oxidative stress, tissue apoptosis, inflammatory response, and neuronal autophagy, it is crucial to understand the underlying pathophysiological mechanisms, local microenvironment changes, and neural tissue functional recovery for preparing novel treatment strategies. Treatment based on cell transplantation has become the forefront of spinal cord injury therapy. The transplanted cells provide physical and nutritional support for the damaged tissue. At the same time, the implantation of biomaterials with specific biological functions at the site of the SCI has also been proved to improve the local inhibitory microenvironment and promote axonal regeneration, etc. The combined transplantation of cells and functional biomaterials for SCI treatment can result in greater neuroprotective and regenerative effects by regulating cell differentiation, enhancing cell survival, and providing physical and directional support for axon regeneration and neural circuit remodeling. This article reviews the pathophysiology of the spinal cord, changes in the microenvironment after injury, and the mechanisms and strategies for spinal cord regeneration and repair. The article will focus on summarizing and discussing the latest intervention models based on cell and functional biomaterial transplantation and the latest progress in combinational therapies in SCI repair. Finally, we propose the future prospects and challenges of current treatment regimens for SCI repair, to provide references for scientists and clinicians to seek better SCI repair strategies in the future.
Collapse
Affiliation(s)
- Tianyi Liu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Wenhao Zhu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Xiaoyu Zhang
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Chuan He
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Xiaolong Liu
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Qiang Xin
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| | - Kexin Chen
- Institute of Translational Medicine, First Hospital of Jilin University, Changchun 130021, China
| | - Haifeng Wang
- Department of Neurosurgery, First Hospital of Jilin University, Changchun 130021, China
| |
Collapse
|
24
|
Corrigendum: Purinergic signaling systems across comparative models of spinal cord injury. Neural Regen Res 2022; 18:689-696. [PMID: 36018196 PMCID: PMC9727416 DOI: 10.4103/1673-5374.350234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
[This corrects the article DOI: 10.4103/1673-5374.338993].
Collapse
|
25
|
Noristani HN. Intrinsic regulation of axon regeneration after spinal cord injury: Recent advances and remaining challenges. Exp Neurol 2022; 357:114198. [DOI: 10.1016/j.expneurol.2022.114198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/20/2022] [Accepted: 08/02/2022] [Indexed: 11/16/2022]
|
26
|
Herwerth M, Kenet S, Schifferer M, Winkler A, Weber M, Snaidero N, Wang M, Lohrberg M, Bennett JL, Stadelmann C, Hemmer B, Misgeld T. A new form of axonal pathology in a spinal model of neuromyelitis optica. Brain 2022; 145:1726-1742. [PMID: 35202467 PMCID: PMC9166560 DOI: 10.1093/brain/awac079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/31/2022] [Accepted: 02/12/2022] [Indexed: 11/14/2022] Open
Abstract
Neuromyelitis optica is a chronic neuroinflammatory disease, which primarily targets astrocytes and often results in severe axon injury of unknown mechanism. Neuromyelitis optica patients harbour autoantibodies against the astrocytic water channel protein, aquaporin-4 (AQP4-IgG), which induce complement-mediated astrocyte lysis and subsequent axon damage. Using spinal in vivo imaging in a mouse model of such astrocytopathic lesions, we explored the mechanism underlying neuromyelitis optica-related axon injury. Many axons showed a swift and morphologically distinct 'pearls-on-string' transformation also readily detectable in human neuromyelitis optica lesions, which especially affected small calibre axons independently of myelination. Functional imaging revealed that calcium homeostasis was initially preserved in this 'acute axonal beading' state, ruling out disruption of the axonal membrane, which sets this form of axon injury apart from previously described forms of traumatic and inflammatory axon damage. Morphological, pharmacological and genetic analyses showed that AQP4-IgG-induced axon injury involved osmotic stress and ionic overload, but does not appear to use canonical pathways of Wallerian-like degeneration. Subcellular analysis demonstrated remodelling of the axonal cytoskeleton in beaded axons, especially local loss of microtubules. Treatment with the microtubule stabilizer epothilone, a putative therapy approach for traumatic and degenerative axonopathies, prevented axonal beading, while destabilizing microtubules sensitized axons for beading. Our results reveal a distinct form of immune-mediated axon pathology in neuromyelitis optica that mechanistically differs from known cascades of post-traumatic and inflammatory axon loss, and suggest a new strategy for neuroprotection in neuromyelitis optica and related diseases.
Collapse
Affiliation(s)
- Marina Herwerth
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Anne Winkler
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Melanie Weber
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Mengzhe Wang
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Melanie Lohrberg
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Jeffrey L. Bennett
- Departments of Neurology and Ophthalmology, Programs in Neuroscience and Immunology, University of Colorado School of Medicine, Aurora, USA
| | - Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
27
|
Self-delivering RNAi compounds as therapeutic agents in the central nervous system to enhance axonal regeneration after injury. iScience 2022; 25:104379. [PMID: 35620420 PMCID: PMC9127586 DOI: 10.1016/j.isci.2022.104379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 12/10/2021] [Accepted: 05/04/2022] [Indexed: 12/01/2022] Open
Abstract
The therapeutic use of RNAi has grown but often faces several hurdles related to delivery systems, compound stability, immune activation, and on-target/off-tissue effects. Self-delivering RNAi (sdRNA) molecules do not require delivery agents or excipients. Here we demonstrate the ability of sdRNA to reduce the expression of PTEN (phosphatase and tensin homolog) to stimulate regenerative axon regrowth in the injured adult CNS. PTEN-targeting sdRNA compounds were tested for efficacy in vivo by intravitreal injection after adult rat optic nerve injury. We describe critical steps in lead compound generation through the optimization of nucleotide modifications, enhancements for stability in biological matrices, and screening for off-target immunostimulatory activity. The data show that PTEN expression in vivo can be reduced using sdRNA and this enhances regeneration in adult CNS neurons after injury, raising the possibility that this method could be utilized for other clinically relevant nervous system indications. self-delivering siRNA (sdRNA) can decrease neuronal gene expression in vivo sdRNA can be successfully delivered in vivo without using vectors or excipients Phosphatase and tensin homolog (PTEN)-targeting sdRNA can enhance CNS neuronal regeneration after injury
Collapse
|
28
|
Kulkarni R, Thakur A, Kumar H. Microtubule Dynamics Following Central and Peripheral Nervous System Axotomy. ACS Chem Neurosci 2022; 13:1358-1369. [PMID: 35451811 DOI: 10.1021/acschemneuro.2c00189] [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] [Indexed: 11/28/2022] Open
Abstract
Disturbance in the neuronal network leads to instability in the microtubule (MT) railroad of axons, causing hindrance in the intra-axonal transport and making it difficult to re-establish the broken network. Peripheral nervous system (PNS) neurons can stabilize their MTs, leading to the formation of regeneration-promoting structures called "growth cones". However, central nervous system (CNS) neurons lack this intrinsic reparative capability and, instead, form growth-incompetent structures called "retraction bulbs", which have a disarrayed MT network. It is evident from various studies that although axonal regeneration depends on both cell-extrinsic and cell-intrinsic factors, any therapy that aims at axonal regeneration ultimately converges onto MTs. Understanding the neuronal MT dynamics will help develop effective therapeutic strategies in diseases where the MT network gets disrupted, such as spinal cord injury, traumatic brain injury, multiple sclerosis, and amyotrophic lateral sclerosis. It is also essential to know the factors that aid or inhibit MT stabilization. In this review, we have discussed the MT dynamics postaxotomy in the CNS and PNS, and factors that can directly influence MT stability in various diseases.
Collapse
Affiliation(s)
- Riya Kulkarni
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat 382355, India
| | - Akshata Thakur
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat 382355, India
| | - Hemant Kumar
- National Institute of Pharmaceutical Education and Research, Ahmedabad, Opposite Air Force Station, Palaj, Gandhinagar, Gujarat 382355, India
| |
Collapse
|
29
|
Slater PG, Domínguez-Romero ME, Villarreal M, Eisner V, Larraín J. Mitochondrial function in spinal cord injury and regeneration. Cell Mol Life Sci 2022; 79:239. [PMID: 35416520 PMCID: PMC11072423 DOI: 10.1007/s00018-022-04261-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 12/21/2022]
Abstract
Many people around the world suffer from some form of paralysis caused by spinal cord injury (SCI), which has an impact on quality and life expectancy. The spinal cord is part of the central nervous system (CNS), which in mammals is unable to regenerate, and to date, there is a lack of full functional recovery therapies for SCI. These injuries start with a rapid and mechanical insult, followed by a secondary phase leading progressively to greater damage. This secondary phase can be potentially modifiable through targeted therapies. The growing literature, derived from mammalian and regenerative model studies, supports a leading role for mitochondria in every cellular response after SCI: mitochondrial dysfunction is the common event of different triggers leading to cell death, cellular metabolism regulates the immune response, mitochondrial number and localization correlate with axon regenerative capacity, while mitochondrial abundance and substrate utilization regulate neural stem progenitor cells self-renewal and differentiation. Herein, we present a comprehensive review of the cellular responses during the secondary phase of SCI, the mitochondrial contribution to each of them, as well as evidence of mitochondrial involvement in spinal cord regeneration, suggesting that a more in-depth study of mitochondrial function and regulation is needed to identify potential targets for SCI therapeutic intervention.
Collapse
Affiliation(s)
- Paula G Slater
- Center for Aging and Regeneration, Departamento de Biología Celular Y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile.
| | - Miguel E Domínguez-Romero
- Center for Aging and Regeneration, Departamento de Biología Celular Y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile
| | - Maximiliano Villarreal
- Center for Aging and Regeneration, Departamento de Biología Celular Y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile
| | - Verónica Eisner
- Center for Aging and Regeneration, Departamento de Biología Celular Y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile
| | - Juan Larraín
- Center for Aging and Regeneration, Departamento de Biología Celular Y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331150, Santiago, Chile
| |
Collapse
|
30
|
Long-term in vivo imaging of mouse spinal cord through an optically cleared intervertebral window. Nat Commun 2022; 13:1959. [PMID: 35414131 PMCID: PMC9005710 DOI: 10.1038/s41467-022-29496-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
The spinal cord accounts for the main communication pathway between the brain and the peripheral nervous system. Spinal cord injury is a devastating and largely irreversible neurological trauma, and can result in lifelong disability and paralysis with no available cure. In vivo spinal cord imaging in mouse models without introducing immunological artifacts is critical to understand spinal cord pathology and discover effective treatments. We developed a minimally invasive intervertebral window by retaining the ligamentum flavum to protect the underlying spinal cord. By introducing an optical clearing method, we achieve repeated two-photon fluorescence and stimulated Raman scattering imaging at subcellular resolution with up to 15 imaging sessions over 6-167 days and observe no inflammatory response. Using this optically cleared intervertebral window, we study neuron-glia dynamics following laser axotomy and observe strengthened contact of microglia with the nodes of Ranvier during axonal degeneration. By enabling long-term, repetitive, stable, high-resolution and inflammation-free imaging of mouse spinal cord, our method provides a reliable platform in the research aiming at interpretation of spinal cord physiology and pathology.
Collapse
|
31
|
Kievit B, Johnstone AD, Gibon J, Barker PA. Mitochondrial Reactive Oxygen Species Mediate Activation of TRPV1 and Calcium Entry Following Peripheral Sensory Axotomy. Front Mol Neurosci 2022; 15:852181. [PMID: 35370552 PMCID: PMC8973397 DOI: 10.3389/fnmol.2022.852181] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Accepted: 02/17/2022] [Indexed: 12/03/2022] Open
Abstract
Axons that are physically separated from their soma activate a series of signaling events that results in axonal self-destruction. A critical element of this signaling pathway is an intra-axonal calcium rise that occurs just prior to axonal fragmentation. Previous studies have shown that preventing this calcium rise delays the onset of axon fragmentation, yet the ion channels responsible for the influx, and the mechanisms by which they are activated, are largely unknown. Axonal injury can be modeled in vitro by transecting murine dorsal root ganglia (DRG) sensory axons. We coupled transections with intra-axonal calcium imaging and found that Ca2+ influx is sharply reduced in axons lacking trpv1 (for transient receptor potential cation channel vanilloid 1) and in axons treated with capsazepine (CPZ), a TRPV1 antagonist. Sensory neurons from trpv1–/– mice were partially rescued from degeneration after transection, indicating that TRPV1 normally plays a pro-degenerative role after axonal injury. TRPV1 activity can be regulated by direct post-translational modification induced by reactive oxygen species (ROS). Here, we tested the hypothesis that mitochondrial ROS production induced by axotomy is required for TRPV1 activity and subsequent axonal degeneration. We found that reducing mitochondrial depolarization with NAD+ supplementation or scavenging ROS using NAC or MitoQ sharply attenuates TRPV1-dependent calcium influx induced by axotomy. This study shows that ROS-dependent TRPV1 activation is required for Ca2+ entry after axotomy.
Collapse
Affiliation(s)
- Bradley Kievit
- Department of Biology, University of British Columbia Okanagan, Kelowna, BC, Canada
| | - Aaron D. Johnstone
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Julien Gibon
- Department of Biology, University of British Columbia Okanagan, Kelowna, BC, Canada
- *Correspondence: Julien Gibon,
| | - Philip A. Barker
- Department of Biology, University of British Columbia Okanagan, Kelowna, BC, Canada
- Philip A. Barker,
| |
Collapse
|
32
|
Kancheva I, Buma F, Kwakkel G, Kancheva A, Ramsey N, Raemaekers M. Investigating secondary white matter degeneration following ischemic stroke by modelling affected fiber tracts. Neuroimage Clin 2022; 33:102945. [PMID: 35124524 PMCID: PMC8829801 DOI: 10.1016/j.nicl.2022.102945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 12/27/2021] [Accepted: 01/17/2022] [Indexed: 11/27/2022]
Abstract
Secondary white matter degeneration was studied in 11 ischemic stroke patients. We used a custom-developed approach to model damaged fibers associated with a lesion. This approach tackles the inter-subject variability in lesion size and location. Findings suggest that secondary degeneration spreads along an entire fiber’s length.
Secondary white matter degeneration is a common occurrence after ischemic stroke, as identified by Diffusion Tensor Imaging (DTI). However, despite recent advances, the time course of the process is not completely understood. The primary aim of this study was to assess secondary degeneration using an approach whereby we create a patient-specific model of damaged fibers based on the volumetric characteristics of lesions. We also examined the effects of secondary degeneration along the modelled streamlines at different distances from the primary infarction using DTI. Eleven patients who presented with upper limb motor deficits at the time of a first-ever ischemic stroke were included. They underwent scanning at weeks 6 and 29 post-stroke. The fractional anisotropy (FA), mean diffusivity (MD), primary eigenvalue (λ1), and transverse eigenvalue (λ23) were measured. Using regions of interest based on the simulation output, the differences between the modelled fibers and matched contralateral areas were analyzed. The longitudinal change between the two time points and across five distances from the primary lesion was also assessed using the ratios of diffusion quantities (rFA, rMD, rλ1, and rλ23) between the ipsilesional and contralesional hemisphere. At week 6 post-stroke, significantly decreased λ1 was found along the ipsilesional corticospinal tract (CST) with a trend towards lower FA, reduced MD and λ23. At week 29 post-stroke, significantly decreased FA was shown relative to the non-lesioned side, with a trend towards lower λ1, unchanged MD, and higher λ23. Along the ipsilesional tract, the rFA diminished, whereas the rMD, rλ1, and rλ23 significantly increased over time. No significant variations in the time progressive effect with distance were demonstrated. The findings support previously described mechanisms of secondary degeneration and suggest that it spreads along the entire length of a damaged tract. Future investigations using higher-order tractography techniques can further explain the intravoxel alterations caused by ischemic injury.
Collapse
Affiliation(s)
- Ivana Kancheva
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, PO Box 85060, 3508AB Utrecht, The Netherlands.
| | - Floor Buma
- Department of Anatomy and Neurosciences, MOVE Research Institute Amsterdam, VU University Medical Center, PO Box 7057, 1007MB Amsterdam, The Netherlands
| | - Gert Kwakkel
- Department of Rehabilitation Medicine, VU University Medical Center, PO Box 7057, 1007MB Amsterdam, The Netherlands
| | - Angelina Kancheva
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, PO Box 85060, 3508AB Utrecht, The Netherlands
| | - Nick Ramsey
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, PO Box 85060, 3508AB Utrecht, The Netherlands
| | - Mathijs Raemaekers
- UMC Utrecht Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, PO Box 85060, 3508AB Utrecht, The Netherlands
| |
Collapse
|
33
|
Brar HK, Dey S, Bhardwaj S, Pande D, Singh P, Dey S, Ghosh-Roy A. Dendrite regeneration in C. elegans is controlled by the RAC GTPase CED-10 and the RhoGEF TIAM-1. PLoS Genet 2022; 18:e1010127. [PMID: 35344539 PMCID: PMC8989329 DOI: 10.1371/journal.pgen.1010127] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 04/07/2022] [Accepted: 02/28/2022] [Indexed: 01/30/2023] Open
Abstract
Neurons are vulnerable to physical insults, which compromise the integrity of both dendrites and axons. Although several molecular pathways of axon regeneration are identified, our knowledge of dendrite regeneration is limited. To understand the mechanisms of dendrite regeneration, we used the PVD neurons in C. elegans with stereotyped branched dendrites. Using femtosecond laser, we severed the primary dendrites and axon of this neuron. After severing the primary dendrites near the cell body, we observed sprouting of new branches from the proximal site within 6 hours, which regrew further with time in an unstereotyped manner. This was accompanied by reconnection between the proximal and distal dendrites, and fusion among the higher-order branches as reported before. We quantified the regeneration pattern into three aspects–territory length, number of branches, and fusion phenomena. Axonal injury causes a retraction of the severed end followed by a Dual leucine zipper kinase-1 (DLK-1) dependent regrowth from the severed end. We tested the roles of the major axon regeneration signalling hubs such as DLK-1-RPM-1, cAMP elevation, let-7 miRNA, AKT-1, Phosphatidylserine (PS) exposure/PS in dendrite regeneration. We found that neither dendrite regrowth nor fusion was affected by the axon injury pathway molecules. Surprisingly, we found that the RAC GTPase, CED-10 and its upstream GEF, TIAM-1 play a cell-autonomous role in dendrite regeneration. Additionally, the function of CED-10 in epidermal cell is critical for post-dendrotomy fusion phenomena. This work describes a novel regulatory mechanism of dendrite regeneration and provides a framework for understanding the cellular mechanism of dendrite regeneration using PVD neuron as a model system. The knowledge of the repair of injured neural circuits comes from the study of the regeneration of injured axons. The information receiving neurites, namely dendrites, are also vulnerable to physical insult during stroke and trauma. However, little knowledge is available on the mechanism of dendrite regeneration since the study of Cajal. In order to get insight into this process, we severed both axon and dendrites of PVD neuron in C. elegans using laser. By comparing the roles of axon regeneration pathways in both dendrite and axon regeneration in this neuron, we found that dendrite regeneration is independent of molecular mechanisms involving axon regrowth. We discovered that dendrite regeneration is dependent on the RAC GTPase CED-10 and GEF TIAM-1. Moreover, we found that CED-10 plays roles within both neuron and in the surrounding epithelia for mounting regeneration response to dendrite injury. This work provides mechanistic insight into the process of dendrite repair after physical injury.
Collapse
Affiliation(s)
- Harjot Kaur Brar
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Swagata Dey
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Smriti Bhardwaj
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Devashish Pande
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Pallavi Singh
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
| | - Shirshendu Dey
- Fluorescence Microscopy Division, Bruker India Scientific Pvt. Ltd., International Trade Tower, Nehru Place, New Delhi, India
| | - Anindya Ghosh-Roy
- Department of Cellular & Molecular Neuroscience, National Brain Research Centre, Manesar, Haryana, India
- * E-mail:
| |
Collapse
|
34
|
Kaplan B, Levenberg S. The Role of Biomaterials in Peripheral Nerve and Spinal Cord Injury: A Review. Int J Mol Sci 2022; 23:ijms23031244. [PMID: 35163168 PMCID: PMC8835501 DOI: 10.3390/ijms23031244] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 12/18/2022] Open
Abstract
Peripheral nerve and spinal cord injuries are potentially devastating traumatic conditions with major consequences for patients’ lives. Severe cases of these conditions are currently incurable. In both the peripheral nerves and the spinal cord, disruption and degeneration of axons is the main cause of neurological deficits. Biomaterials offer experimental solutions to improve these conditions. They can be engineered as scaffolds that mimic the nerve tissue extracellular matrix and, upon implantation, encourage axonal regeneration. Furthermore, biomaterial scaffolds can be designed to deliver therapeutic agents to the lesion site. This article presents the principles and recent advances in the use of biomaterials for axonal regeneration and nervous system repair.
Collapse
Affiliation(s)
- Ben Kaplan
- Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel;
- Bruce Rapaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3525433, Israel
| | - Shulamit Levenberg
- Faculty of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa 3200003, Israel;
- Correspondence:
| |
Collapse
|
35
|
Varadarajan SG, Hunyara JL, Hamilton NR, Kolodkin AL, Huberman AD. Central nervous system regeneration. Cell 2022; 185:77-94. [PMID: 34995518 PMCID: PMC10896592 DOI: 10.1016/j.cell.2021.10.029] [Citation(s) in RCA: 75] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 02/06/2023]
Abstract
Neurons of the mammalian central nervous system fail to regenerate. Substantial progress has been made toward identifying the cellular and molecular mechanisms that underlie regenerative failure and how altering those pathways can promote cell survival and/or axon regeneration. Here, we summarize those findings while comparing the regenerative process in the central versus the peripheral nervous system. We also highlight studies that advance our understanding of the mechanisms underlying neural degeneration in response to injury, as many of these mechanisms represent primary targets for restoring functional neural circuits.
Collapse
Affiliation(s)
| | - John L Hunyara
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Natalie R Hamilton
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Andrew D Huberman
- Department of Neurobiology, Stanford University, Stanford, CA 94305, USA; Department of Ophthalmology, Stanford University, Stanford, CA 94305, USA.
| |
Collapse
|
36
|
Hastings N, Kuan WL, Osborne A, Kotter MRN. Therapeutic Potential of Astrocyte Transplantation. Cell Transplant 2022; 31:9636897221105499. [PMID: 35770772 PMCID: PMC9251977 DOI: 10.1177/09636897221105499] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cell transplantation is an attractive treatment strategy for a variety of brain disorders, as it promises to replenish lost functions and rejuvenate the brain. In particular, transplantation of astrocytes has come into light recently as a therapy for amyotrophic lateral sclerosis (ALS); moreover, grafting of astrocytes also showed positive results in models of other conditions ranging from neurodegenerative diseases of older age to traumatic injury and stroke. Despite clear differences in etiology, disorders such as ALS, Parkinson's, Alzheimer's, and Huntington's diseases, as well as traumatic injury and stroke, converge on a number of underlying astrocytic abnormalities, which include inflammatory changes, mitochondrial damage, calcium signaling disturbance, hemichannel opening, and loss of glutamate transporters. In this review, we examine these convergent pathways leading to astrocyte dysfunction, and explore the existing evidence for a therapeutic potential of transplantation of healthy astrocytes in various models. Existing literature presents a wide variety of methods to generate astrocytes, or relevant precursor cells, for subsequent transplantation, while described outcomes of this type of treatment also differ between studies. We take technical differences between methodologies into account to understand the variability of therapeutic benefits, or lack thereof, at a deeper level. We conclude by discussing some key requirements of an astrocyte graft that would be most suitable for clinical applications.
Collapse
Affiliation(s)
- Nataly Hastings
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Wei-Li Kuan
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Andrew Osborne
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Mark R N Kotter
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.,Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| |
Collapse
|
37
|
In vivo imaging in experimental spinal cord injury – Techniques and trends. BRAIN AND SPINE 2022; 2:100859. [PMID: 36248104 PMCID: PMC9560701 DOI: 10.1016/j.bas.2021.100859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 12/15/2021] [Accepted: 12/22/2021] [Indexed: 11/23/2022]
Abstract
Introduction Traumatic Spinal Cord Injury (SCI) is one of the leading causes of disability in the world. Treatment is limited to supportive care and no curative therapy exists. Experimental research to understand the complex pathophysiology and potential mediators of spinal cord regeneration is essential to develop innovative translational therapies. A multitude of experimental imaging methods to monitor spinal cord regeneration in vivo have developed over the last years. However, little literature exists to deal with advanced imaging methods specifically available in SCI research. Research Question This systematic literature review examines the current standards in experimental imaging in SCI allowing for in vivo imaging of spinal cord regeneration on a neuronal, vascular, and cellular basis. Material and Methods Articles were included meeting the following criteria: experimental research, original studies, rodent subjects, and intravital imaging. Reviewed in detail are microstructural and functional Magnetic Resonance Imaging, Micro-Computed Tomography, Laser Speckle Imaging, Very High Resolution Ultrasound, and in vivo microscopy techniques. Results Following the PRISMA guidelines for systematic reviews, 689 articles were identified for review, of which 492 were sorted out after screening and an additional 104 after detailed review. For qualitative synthesis 93 articles were included in this publication. Discussion and Conclusion With this study we give an up-to-date overview about modern experimental imaging techniques with the potential to advance the knowledge on spinal cord regeneration following SCI. A thorough knowledge of the strengths and limitations of the reviewed techniques will help to optimally exploit our current experimental armamentarium in the field. In vivo imaging is essential to enhance the understanding of SCI pathophysiology. Multiple experimental imaging methods have evolved over the past years. Detailed review of in vivo (f)MRI, μCT, VHRUS, and Microcopy in experimental SCI. Experimental imaging allows for longitudinal examination to the cellular level. Knowledge of the strengths and limitations is essential for future research.
Collapse
|
38
|
Eliseeva NM, Serova NK, Pitskhelauri DI, Kuchina OB, Kudieva ES. [Retrograde degeneration of visual pathway]. ZHURNAL VOPROSY NEIROKHIRURGII IMENI N. N. BURDENKO 2021; 85:92-96. [PMID: 34951765 DOI: 10.17116/neiro20218506192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Optical coherence tomography (OCT) gives the opportunity to examine retrograde degeneration of visual pathway damaged at various levels. OBJECTIVE To estimate OCT data on retrograde degeneration of visual pathway damaged at various levels. MATERIAL AND METHODS Ganglion cell layer (GCL) thickness was measured by OCT in 79 patients with visual pathway damaged at various levels and known duration of visual disturbances. Twenty-One patients were diagnosed with traumatic lesions of the optic nerves and/or chiasma. Fifty-eight patients had retro-genicular visual pathway damage. Thirty-three patients were examined for postoperative homonymous hemianopia after surgery for drug-resistant temporal lobe epilepsy. Twenty-five patients were diagnosed with occipital lobe damage following stroke (12 patients), surgery for arteriovenous malformation (11 patients) and traumatic brain injury (2 patients). All patients underwent assessment of visual acuity, automatic static perimetry, MRI/CT of the brain. Retinal ganglion cell complex was analyzed during OCT. RESULTS GCL thinning following anterior visual pathway damage was detected in 20 out of 21 patients after ≥22 days. In case of post-genicular visual pathway damage, GCL thinning was found in 25 out of 58 patients (9 out of 33 ones after surgery for temporal lobe epilepsy and 16 out of 25 patients with occipital lobe lesion). After surgery for temporal lobe epilepsy, minimum period until GCL thinning detection after previous visual pathway damage was 3 months, in case of occipital lobe lesion - 5 months. CONCLUSION Retrograde visual pathway degeneration is followed by GCL thinning and depends on the level of visual pathway lesion.
Collapse
Affiliation(s)
| | - N K Serova
- Burdenko Neurosurgical Center, Moscow, Russia
| | | | - O B Kuchina
- Burdenko Neurosurgical Center, Moscow, Russia
| | - E S Kudieva
- Burdenko Neurosurgical Center, Moscow, Russia
| |
Collapse
|
39
|
Zottoli SJ, Faber DS, Hering J, Dannhauer AC, Northen S. Survival and Axonal Outgrowth of the Mauthner Cell Following Spinal Cord Crush Does Not Drive Post-injury Startle Responses. Front Cell Dev Biol 2021; 9:744191. [PMID: 34869332 PMCID: PMC8640457 DOI: 10.3389/fcell.2021.744191] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022] Open
Abstract
A pair of Mauthner cells (M-cells) can be found in the hindbrain of most teleost fish, as well as amphibians and lamprey. The axons of these reticulospinal neurons cross the midline and synapse on interneurons and motoneurons as they descend the length of the spinal cord. The M-cell initiates fast C-type startle responses (fast C-starts) in goldfish and zebrafish triggered by abrupt acoustic/vibratory stimuli. Starting about 70 days after whole spinal cord crush, less robust startle responses with longer latencies manifest in adult goldfish, Carassius auratus. The morphological and electrophysiological identifiability of the M-cell provides a unique opportunity to study cellular responses to spinal cord injury and the relation of axonal regrowth to a defined behavior. After spinal cord crush at the spinomedullary junction about one-third of the damaged M-axons of adult goldfish send at least one sprout past the wound site between 56 and 85 days postoperatively. These caudally projecting sprouts follow a more lateral trajectory relative to their position in the fasciculus longitudinalis medialis of control fish. Other sprouts, some from the same axon, follow aberrant pathways that include rostral projections, reversal of direction, midline crossings, neuromas, and projection out the first ventral root. Stimulating M-axons in goldfish that had post-injury startle behavior between 198 and 468 days postoperatively resulted in no or minimal EMG activity in trunk and tail musculature as compared to control fish. Although M-cells can survive for at least 468 day (∼1.3 years) after spinal cord crush, maintain regrowth, and elicit putative trunk EMG responses, the cell does not appear to play a substantive role in the emergence of acoustic/vibratory-triggered responses. We speculate that aberrant pathway choice of this neuron may limit its role in the recovery of behavior and discuss structural and functional properties of alternative candidate neurons that may render them more supportive of post-injury startle behavior.
Collapse
Affiliation(s)
- Steven J Zottoli
- Department of Biology, Williams College, Williamstown, MA, United States.,Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA, United States
| | - Donald S Faber
- Albert Einstein College of Medicine, Rose F. Kennedy Center, Bronx, NY, United States
| | - John Hering
- Department of Biology, Williams College, Williamstown, MA, United States
| | - Ann C Dannhauer
- Department of Biology, Williams College, Williamstown, MA, United States
| | - Susan Northen
- Department of Biology, Williams College, Williamstown, MA, United States
| |
Collapse
|
40
|
Wang YX, Bai JZ, Lyu Z, Zhang GH, Huo XL. Oscillating field stimulation promotes axon regeneration and locomotor recovery after spinal cord injury. Neural Regen Res 2021; 17:1318-1323. [PMID: 34782577 PMCID: PMC8643069 DOI: 10.4103/1673-5374.327349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Oscillating field stimulation (OFS) is a potential method for treating spinal cord injury. Although it has been used in spinal cord injury (SCI) therapy in basic and clinical studies, its underlying mechanism and the correlation between its duration and nerve injury repair remain poorly understood. In this study, we established rat models of spinal cord contusion at T10 and then administered 12 weeks of OFS. The results revealed that effectively promotes the recovery of motor function required continuous OFS for more than 6 weeks. The underlying mechanism may be related to the effects of OFS on promoting axon regeneration, inhibiting astrocyte proliferation, and improving the linear arrangement of astrocytes. This study was approved by the Animal Experiments and Experimental Animal Welfare Committee of Capital Medical University (supplemental approval No. AEEI-2021-204) on July 26, 2021.
Collapse
Affiliation(s)
- Yi-Xin Wang
- Department of Spine and Spinal Cord Surgery, Beijing Bo'ai Hospital, Rehabilitation Research Center; School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Jin-Zhu Bai
- Department of Spine and Spinal Cord Surgery, Beijing Bo'ai Hospital, Rehabilitation Research Center; School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Zhen Lyu
- Department of Spine and Spinal Cord Surgery, Beijing Bo'ai Hospital, Rehabilitation Research Center; School of Rehabilitation Medicine, Capital Medical University, Beijing, China
| | - Guang-Hao Zhang
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences; School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| | - Xiao-Lin Huo
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences; School of Electronics, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
41
|
Zeman RJ, Wen X, Ouyang N, Brown AM, Etlinger JD. Role of the Polyol Pathway in Locomotor Recovery and Wallerian Degeneration after Spinal Cord Contusion Injury. Neurotrauma Rep 2021; 2:411-423. [PMID: 34738094 PMCID: PMC8563458 DOI: 10.1089/neur.2021.0018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Spinal cord contusion injury leads to Wallerian degeneration of axonal tracts, resulting in irreversible paralysis. Contusion injury causes perfusion loss by thrombosis and vasospasm, resulting in spinal cord ischemia. In several tissues, including heart and brain, ischemia activates polyol pathway enzymes—aldose reductase (AR) and sorbitol dehydrogenase (SDH)—that convert glucose to sorbitol and fructose in reactions, causing oxidative stress and tissue loss. We sought to determine whether activation of this pathway, which has been termed glucotoxicity, contributes to tissue loss after spinal cord contusion injury. We tested individual treatments with AR inhibitors (sorbinil or ARI-809), SDH inhibitor (CP-470711), superoxide dismutase mimetic (tempol), or combined sorbinil and tempol. Each treatment significantly increased locomotor recovery and reduced loss of spinal cord tissue in a standard model of spinal cord contusion in rats. Tissue levels of sorbitol and axonal AR (AKR1B10) expression were increased after contusion injury, consistent with activation of the polyol pathway. Sorbinil treatment inhibited the above changes and also decreased axonal swelling and loss, characteristic of Wallerian degeneration. Treatment with tempol induced recovery of locomotor function that was similar in magnitude, but non-additive to sorbinil, suggesting a shared mechanism of action by reactive oxygen species (ROS). Exogenous induction of hyperglycemia further increased injury-induced axonal swelling, consistent with glucotoxicity. Unexpectedly, contusion increased spinal cord levels of glucose, the primary polyol pathway substrate. These results support roles for spinal glucose elevation and tissue glucotoxicity by the polyol pathway after spinal cord contusion injury that results in ROS-mediated axonal degeneration.
Collapse
Affiliation(s)
- Richard J Zeman
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA.,MotoGen Inc., Mount Kisco, New York, USA
| | - Xialing Wen
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Nengtai Ouyang
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Abraham M Brown
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA
| | - Joseph D Etlinger
- Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York, USA.,MotoGen Inc., Mount Kisco, New York, USA
| |
Collapse
|
42
|
Palumbo A, Grüning P, Landt SK, Heckmann LE, Bartram L, Pabst A, Flory C, Ikhsan M, Pietsch S, Schulz R, Kren C, Koop N, Boltze J, Madany Mamlouk A, Zille M. Deep Learning to Decipher the Progression and Morphology of Axonal Degeneration. Cells 2021; 10:cells10102539. [PMID: 34685519 PMCID: PMC8534012 DOI: 10.3390/cells10102539] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/19/2021] [Accepted: 09/22/2021] [Indexed: 11/16/2022] Open
Abstract
Axonal degeneration (AxD) is a pathological hallmark of many neurodegenerative diseases. Deciphering the morphological patterns of AxD will help to understand the underlying mechanisms and develop effective therapies. Here, we evaluated the progression of AxD in cortical neurons using a novel microfluidic device together with a deep learning tool that we developed for the enhanced-throughput analysis of AxD on microscopic images. The trained convolutional neural network (CNN) sensitively and specifically segmented the features of AxD including axons, axonal swellings, and axonal fragments. Its performance exceeded that of the human evaluators. In an in vitro model of AxD in hemorrhagic stroke induced by the hemolysis product hemin, we detected a time-dependent degeneration of axons leading to a decrease in axon area, while axonal swelling and fragment areas increased. Axonal swellings preceded axon fragmentation, suggesting that swellings may be reliable predictors of AxD. Using a recurrent neural network (RNN), we identified four morphological patterns of AxD (granular, retraction, swelling, and transport degeneration). These findings indicate a morphological heterogeneity of AxD in hemorrhagic stroke. Our EntireAxon platform enables the systematic analysis of axons and AxD in time-lapse microscopy and unravels a so-far unknown intricacy in which AxD can occur in a disease context.
Collapse
Affiliation(s)
- Alex Palumbo
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, 23562 Lübeck, Germany
| | - Philipp Grüning
- Institute for Neuro- and Bioinformatics, University of Lübeck, 23562 Lübeck, Germany; (P.G.); (A.M.M.)
| | - Svenja Kim Landt
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
| | - Lara Eleen Heckmann
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
| | - Luisa Bartram
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
| | - Alessa Pabst
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
| | - Charlotte Flory
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
| | - Maulana Ikhsan
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, 23562 Lübeck, Germany
- Faculty of Medicine, Malikussaleh University, Lhokseumawe 24355, Indonesia
| | - Sören Pietsch
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
- Department of Neonatology, Universitätsklinikum Leipzig, 04103 Leipzig, Germany
| | - Reinhard Schulz
- Wissenschaftliche Werkstätten, University of Lübeck, 23562 Lübeck, Germany;
| | - Christopher Kren
- Medical Laser Center Lübeck GmbH, 23562 Lübeck, Germany; (C.K.); (N.K.)
| | - Norbert Koop
- Medical Laser Center Lübeck GmbH, 23562 Lübeck, Germany; (C.K.); (N.K.)
| | - Johannes Boltze
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
- School of Life Sciences, The University of Warwick, Gibbet Hill Campus, Coventry CV4 7AL, UK
| | - Amir Madany Mamlouk
- Institute for Neuro- and Bioinformatics, University of Lübeck, 23562 Lübeck, Germany; (P.G.); (A.M.M.)
| | - Marietta Zille
- Fraunhofer Research and Development Center for Marine and Cellular Biotechnology EMB, 23562 Lübeck, Germany; (A.P.); (S.K.L.); (L.E.H.); (L.B.); (A.P.); (C.F.); (M.I.); (S.P.); (J.B.)
- Institute for Medical and Marine Biotechnology, University of Lübeck, 23562 Lübeck, Germany
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, 23562 Lübeck, Germany
- Department of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, University of Vienna, 1090 Vienna, Austria
- Correspondence:
| |
Collapse
|
43
|
Mahadewa TGB, Mardhika PE, Awyono S, Putra MB, Saapang GS, Wiyanjana KDF, Putra KK, Natakusuma TISD, Ryalino C. Mesenteric Neural Stem Cell for Chronic Spinal Cord Injury: A Literature Review. Open Access Maced J Med Sci 2021. [DOI: 10.3889/oamjms.2021.6653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Spinal cord injury (SCI) is a common and potentially life-threatening condition with no established treatment to treat the primary injury. Mesenteric neural stem cell (NSC) therapy is a promising stem cell therapy to treat primary SCI in the chronic phase. We aimed to review the literature narratively to describe current evidence regarding mesenteric NSC in SCI. Primary SCI refers to tissue damage that occurs at the time of trauma that leads to the death of neuronal cells. In chronic SCI, the ability of neuronal regeneration is compromised by the development of gliotic scar. NSC is a stem cell therapy that targeted SCI in the chronic phase. Enteric NSC is one of the sources of NSC, and autologous gut harvesting in the appendix using endoscopic surgery provides a more straightforward and low-risk procedure. Intramedullary transplantation of stem cell with ultrasound guiding is administration technique which offers long-term regeneration. Mesenteric NSC is a promising stem cell therapy to treat chronic SCI with low risk and easier procedure to isolate cells compared to other NSC sources.
Collapse
|
44
|
Fedorova J, Kellerova E, Bimbova K, Pavel J. The Histopathology of Severe Graded Compression in Lower Thoracic Spinal Cord Segment of Rat, Evaluated at Late Post-injury Phase. Cell Mol Neurobiol 2021; 42:173-193. [PMID: 34410553 PMCID: PMC8732890 DOI: 10.1007/s10571-021-01139-7] [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: 05/20/2021] [Accepted: 08/04/2021] [Indexed: 11/28/2022]
Abstract
Spontaneous recovery of lost motor functions is relative fast in rodent models after inducing a very mild/moderate spinal cord injury (SCI), and this may complicate a reliable evaluation of the effectiveness of potential therapy. Therefore, a severe graded (30 g, 40 g and 50 g) weight-compression SCI at the Th9 spinal segment, involving an acute mechanical impact followed by 15 min of persistent compression, was studied in adult female Wistar rats. Functional parameters, such as spontaneous recovery of motor hind limb and bladder emptying function, and the presence of hematuria were evaluated within 28 days of the post-traumatic period. The disruption of the blood-spinal cord barrier, measured by extravasated Evans Blue dye, was examined 24 h after the SCI, when maximum permeability occurs. At the end of the survival period, the degradation of gray and white matter associated with the formation of cystic cavities, and quantitative changes of glial structural proteins, such as GFAP, and integral components of axonal architecture, such as neurofilaments and myelin basic protein, were evaluated in the lesioned area of the spinal cord. Based on these functional and histological parameters, and taking the animal’s welfare into account, the 40 g weight can be considered as an upper limit for severe traumatic injury in this compression model.
Collapse
Affiliation(s)
- Jana Fedorova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Erika Kellerova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Katarina Bimbova
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia
| | - Jaroslav Pavel
- Department of Neurodegeneration, Plasticity and Repair, Institute of Neurobiology, Biomedical Research Center of the Slovak Academy of Sciences, Soltesovej 4-6, 040 01, Kosice, Slovakia.
| |
Collapse
|
45
|
Unraveling Axon Guidance during Axotomy and Regeneration. Int J Mol Sci 2021; 22:ijms22158344. [PMID: 34361110 PMCID: PMC8347220 DOI: 10.3390/ijms22158344] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 02/06/2023] Open
Abstract
During neuronal development and regeneration axons extend a cytoskeletal-rich structure known as the growth cone, which detects and integrates signals to reach its final destination. The guidance cues “signals” bind their receptors, activating signaling cascades that result in the regulation of the growth cone cytoskeleton, defining growth cone advance, pausing, turning, or collapse. Even though much is known about guidance cues and their isolated mechanisms during nervous system development, there is still a gap in the understanding of the crosstalk between them, and about what happens after nervous system injuries. After neuronal injuries in mammals, only axons in the peripheral nervous system are able to regenerate, while the ones from the central nervous system fail to do so. Therefore, untangling the guidance cues mechanisms, as well as their behavior and characterization after axotomy and regeneration, are of special interest for understanding and treating neuronal injuries. In this review, we present findings on growth cone guidance and canonical guidance cues mechanisms, followed by a description and comparison of growth cone pathfinding mechanisms after axotomy, in regenerative and non-regenerative animal models.
Collapse
|
46
|
Fague L, Liu YA, Marsh-Armstrong N. The basic science of optic nerve regeneration. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:1276. [PMID: 34532413 PMCID: PMC8421956 DOI: 10.21037/atm-20-5351] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 01/15/2021] [Indexed: 12/25/2022]
Abstract
Diverse insults to the optic nerve result in partial to total vision loss as the axons of retinal ganglion cells are destroyed. In glaucoma, axons are injured at the optic nerve head; in other optic neuropathies, axons can be damaged along the entire visual pathway. In all cases, as mammals cannot regenerate injured central nervous system cells, once the axons are lost, vision loss is irreversible. However, much has been learned about how retinal ganglion cells respond to axon injuries, and many of these crucial discoveries offer hope for future regenerative therapies. Here we review the current understanding regarding the temporal progression of axonal degeneration. We summarize known survival and regenerative mechanisms in mammals, including specific signaling pathways, key transcription factors, and reprogramming genes. We cover mechanisms intrinsic to retinal ganglion cells as well as their interactions with myeloid and glial cell populations in the retina and optic nerve that affect survival and regeneration. Finally, we highlight some non-mammalian species that are able to regenerate their retinal ganglion cell axons after injury, as understanding these successful regenerative responses may be essential to the rational design of future clinical interventions to regrow the optic nerve. In the end, a combination of many different molecular and cellular interventions will likely be the only way to achieve functional recovery of vision and restore quality of life to millions of patients around the world.
Collapse
Affiliation(s)
- Lindsay Fague
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Yin Allison Liu
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| | - Nicholas Marsh-Armstrong
- UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis, Sacramento, CA, USA
| |
Collapse
|
47
|
Van Broeckhoven J, Sommer D, Dooley D, Hendrix S, Franssen AJPM. Macrophage phagocytosis after spinal cord injury: when friends become foes. Brain 2021; 144:2933-2945. [PMID: 34244729 DOI: 10.1093/brain/awab250] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/12/2021] [Accepted: 06/20/2021] [Indexed: 11/14/2022] Open
Abstract
After spinal cord injury (SCI), macrophages can exert either beneficial or detrimental effects depending on their phenotype. Aside from their critical role in inflammatory responses, macrophages are also specialized in the recognition, engulfment, and degradation of pathogens, apoptotic cells, and tissue debris. They promote remyelination and axonal regeneration by removing inhibitory myelin components and cellular debris. However, excessive intracellular presence of lipids and dysregulated intracellular lipid homeostasis result in the formation of foamy macrophages. These develop a pro-inflammatory phenotype that may contribute to further neurological decline. Additionally, myelin-activated macrophages play a crucial role in axonal dieback and retraction. Here, we review the opposing functional consequences of phagocytosis by macrophages in SCI, including remyelination and regeneration versus demyelination, degeneration, and axonal dieback. Furthermore, we discuss how targeting the phagocytic ability of macrophages may have therapeutic potential for the treatment of SCI.
Collapse
Affiliation(s)
- Jana Van Broeckhoven
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Daniela Sommer
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| | - Dearbhaile Dooley
- School of Medicine, Health Sciences Centre, University College Dublin, Belfield Dublin 4, Ireland.,UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland
| | - Sven Hendrix
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium.,Medical School Hamburg, Hamburg, Germany
| | - Aimée J P M Franssen
- Department of Immunology and Infection, Biomedical Research Institute, Hasselt University, Diepenbeek, Belgium
| |
Collapse
|
48
|
Ren S, Zhang W, Liu H, Wang X, Guan X, Zhang M, Zhang J, Wu Q, Xue Y, Wang D, Liu Y, Liu J, Ren X. Transplantation of a vascularized pedicle of hemisected spinal cord to establish spinal cord continuity after removal of a segment of the thoracic spinal cord: A proof-of-principle study in dogs. CNS Neurosci Ther 2021; 27:1182-1197. [PMID: 34184402 PMCID: PMC8446222 DOI: 10.1111/cns.13696] [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: 03/02/2021] [Revised: 06/02/2021] [Accepted: 06/06/2021] [Indexed: 12/14/2022] Open
Abstract
Introduction Glial scar formation impedes nerve regeneration/reinnervation after spinal cord injury (SCI); therefore, removal of scar tissue is essential for SCI treatment. Aims To investigate whether removing a spinal cord and transplanting a vascularized pedicle of hemisected spinal cord from the spinal cord caudal to the transection can restore motor function, to aid in the treatment of future clinical spinal cord injuries. We developed a canine model. After removal of a 1‐cm segment of the thoracic (T10–T11) spinal cord in eight beagles, a vascularized pedicle of hemisected spinal cord from the first 1.5 cm of the spinal cord caudal to the transection (cut along the posterior median sulcus of the spinal cord) was transplanted to bridge the transected spinal cord in the presence of a fusogen (polyethylene glycol, PEG) in four of the eight dogs. We used various forms of imaging, electron microscopy, and histologic data to determine that after our transplantation of a vascular pedicled hemisection to bridge the transected spinal cord, electrical continuity across the spinal bridge was restored. Results Motor function was restored following our transplantation, as confirmed by the re‐establishment of anatomic continuity along with interfacial axonal sprouting. Conclusion Taken together, our findings suggest that SCI patients—who have previously been thought to have irreversible damage and/or paralysis—may be treated effectively with similar operative techniques to re‐establish electrical and functional continuity following SCI.
Collapse
Affiliation(s)
- Shuai Ren
- Hand and Microsurgery Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,State-Province Key Laboratories of Biomedicine-Pharmaceutics, Harbin Medical University, Harbin, China.,Global Initiative to Cure Paralysis (GICUP), Columbus, OH, USA
| | - Weihua Zhang
- Global Initiative to Cure Paralysis (GICUP), Columbus, OH, USA.,Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China.,Institute of Orthopedic, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| | - HongMiao Liu
- Department of Pathology, The General Hospital of Heilongjiang Farms & Land Reclamation Administration Harbin, Harbin, China
| | - Xin Wang
- Department of Pathology, The General Hospital of Heilongjiang Farms & Land Reclamation Administration Harbin, Harbin, China
| | - Xiangchen Guan
- Hand and Microsurgery Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,State-Province Key Laboratories of Biomedicine-Pharmaceutics, Harbin Medical University, Harbin, China
| | - Mingzhe Zhang
- Hand and Microsurgery Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,State-Province Key Laboratories of Biomedicine-Pharmaceutics, Harbin Medical University, Harbin, China
| | - Jian Zhang
- Hand and Microsurgery Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,State-Province Key Laboratories of Biomedicine-Pharmaceutics, Harbin Medical University, Harbin, China
| | - Qiong Wu
- Department of MR Diagnosis, The Second Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yan Xue
- Department of Orthopaedics, The Fifth Hospital of Harbin, Harbin, China
| | - Dan Wang
- Department of Pathology, The General Hospital of Heilongjiang Farms & Land Reclamation Administration Harbin, Harbin, China
| | - Yong Liu
- Department of Orthopaedics, The Fifth Hospital of Harbin, Harbin, China
| | - Jianyu Liu
- Hand and Microsurgery Center, The Second Affiliated Hospital of Harbin Medical University, Harbin, China.,State-Province Key Laboratories of Biomedicine-Pharmaceutics, Harbin Medical University, Harbin, China
| | - Xiaoping Ren
- Global Initiative to Cure Paralysis (GICUP), Columbus, OH, USA.,Department of Orthopedics, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China.,Institute of Orthopedic, Ruikang Hospital Affiliated to Guangxi University of Chinese Medicine, Nanning, China
| |
Collapse
|
49
|
Zhan J, Fegg FN, Kaddatz H, Rühling S, Frenz J, Denecke B, Amor S, Ponsaerts P, Hochstrasser T, Kipp M. Focal white matter lesions induce long-lasting axonal degeneration, neuroinflammation and behavioral deficits. Neurobiol Dis 2021; 155:105371. [PMID: 33932559 DOI: 10.1016/j.nbd.2021.105371] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 03/25/2021] [Accepted: 04/26/2021] [Indexed: 12/16/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS) with episodes of inflammatory demyelination and remyelination. While remyelination has been linked with functional recovery in MS patients, there is evidence of ongoing tissue damage despite complete myelin repair. In this study, we investigated the long-term consequences of an acute demyelinating white matter CNS lesion. For this purpose, acute demyelination was induced by 5-week-cuprizone intoxication in male C57BL/6 J mice, and the tissues were examined after a 7-month recovery period. While myelination and oligodendrocyte densities appeared normal, ongoing axonal degeneration and glia cell activation were found in the remyelinated corpus callosum. Neuropathologies were paralleled by subtle gait abnormalities evaluated using DigiGait™ high speed ventral plane videography. Gene array analyses revealed increased expression levels of various inflammation related genes, among protein kinase c delta (PRKCD). Immunofluorescence stains revealed predominant microglia/macrophages PRKCD expression in both, cuprizone tissues and post-mortem MS lesions. These results support the hypothesis that chronic microglia/macrophages driven tissue injury represents a key aspect of progressive neurodegeneration and functional decline in MS.
Collapse
Affiliation(s)
- Jiangshan Zhan
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Florian Nepomuk Fegg
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Hannes Kaddatz
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Sebastian Rühling
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Julia Frenz
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Bernd Denecke
- Interdisciplinary Center for Clinical Research Aachen (IZKF Aachen), RWTH Aachen University, Aachen, Germany
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, VUMC site, Amsterdam, the Netherlands; Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Peter Ponsaerts
- Faculty of Medicine and Health Sciences, University of Antwerp, Antwerp 2610, Belgium
| | - Tanja Hochstrasser
- Department of Anatomy II, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Markus Kipp
- Institute of Anatomy, Rostock University Medical Center, Rostock, Germany; Center for Transdisciplinary Neurosciences Rostock (CTNR), Rostock University Medical Center, Gelsheimer Strasse 20, 18147 Rostock, Germany.
| |
Collapse
|
50
|
Nazareth L, St John J, Murtaza M, Ekberg J. Phagocytosis by Peripheral Glia: Importance for Nervous System Functions and Implications in Injury and Disease. Front Cell Dev Biol 2021; 9:660259. [PMID: 33898462 PMCID: PMC8060502 DOI: 10.3389/fcell.2021.660259] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 03/17/2021] [Indexed: 12/30/2022] Open
Abstract
The central nervous system (CNS) has very limited capacity to regenerate after traumatic injury or disease. In contrast, the peripheral nervous system (PNS) has far greater capacity for regeneration. This difference can be partly attributed to variances in glial-mediated functions, such as axon guidance, structural support, secretion of growth factors and phagocytic activity. Due to their growth-promoting characteristic, transplantation of PNS glia has been trialed for neural repair. After peripheral nerve injuries, Schwann cells (SCs, the main PNS glia) phagocytose myelin debris and attract macrophages to the injury site to aid in debris clearance. One peripheral nerve, the olfactory nerve, is unique in that it continuously regenerates throughout life. The olfactory nerve glia, olfactory ensheathing cells (OECs), are the primary phagocytes within this nerve, continuously clearing axonal debris arising from the normal regeneration of the nerve and after injury. In contrast to SCs, OECs do not appear to attract macrophages. SCs and OECs also respond to and phagocytose bacteria, a function likely critical for tackling microbial invasion of the CNS via peripheral nerves. However, phagocytosis is not always effective; inflammation, aging and/or genetic factors may contribute to compromised phagocytic activity. Here, we highlight the diverse roles of SCs and OECs with the focus on their phagocytic activity under physiological and pathological conditions. We also explore why understanding the contribution of peripheral glia phagocytosis may provide us with translational strategies for achieving axonal regeneration of the injured nervous system and potentially for the treatment of certain neurological diseases.
Collapse
Affiliation(s)
- Lynn Nazareth
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia
| | - James St John
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Mariyam Murtaza
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| | - Jenny Ekberg
- Menzies Health Institute Queensland, Griffith University, Southport, QLD, Australia.,Clem Jones Centre for Neurobiology and Stem Cell Research, Griffith University, Nathan, QLD, Australia.,Griffith Institute for Drug Discovery, Griffith University, Nathan, QLD, Australia
| |
Collapse
|