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Xu ZX, Xu D, Fang F, Fan YJ, Wu B, Chen YF, Huang HE, Huang XH, Zhuang YH, Xu WH. Enhanced axon outgrowth of spinal motor neurons in co-culturing with dorsal root ganglions antagonizes the growth inhibitory environment. Regen Ther 2024; 25:68-76. [PMID: 38148872 PMCID: PMC10750115 DOI: 10.1016/j.reth.2023.11.013] [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] [Received: 09/23/2023] [Revised: 11/09/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023] Open
Abstract
Introduction Forming a bridge made of functional axons to span the lesion is essential to reconstruct the motor circuitry following spinal cord injury (SCI). Dorsal root ganglion (DRG) axons are robust in axon growth and have been proved to facilitate the growth of cortical neurons in a process of axon-facilitated axon regeneration. However, whether DRG transplantation affects the axon outgrowth of spinal motor neurons (SMNs) that play crucial roles in motor circuitry remains unclear. Methods We investigated the axonal growth patterns of co-cultured DRGs and SMN aggregates (SMNAs) taking advantage of a well-designed 3D-printed in vitro system. Chondroitin sulphate proteoglycans (CSPG) induced inhibitory matrix was introduced to imitate the inhibitory environment following SCI. Axonal lengths of DRG, SMNA or DRG & SMNA cultured on the permissive or CSPG induced inhibitory matrix were measured and compared. Results Our results indicated that under the guidance of full axonal connection generated from two opposing populations of DRGs, SMNA axons were growth-enhanced and elongated along the DRG axon bridge to distances that they could not otherwise reach. Quantitatively, the co-culture increased the SMNA axonal length by 32.1 %. Moreover, the CSPG matrix reduced the axonal length of DRGs and SMNAs by 46.2 % and 17.7 %, respectively. This inhibitory effect was antagonized by the co-culture of DRGs and SMNAs. Especially for SMNAs, they extended the axons across the CSPG-coating matrix, reached the lengths close to those of SMNAs cultured on the permissive matrix alone. Conclusions This study deepens our understanding of axon-facilitated reconstruction of the motor circuitry. Moreover, the results support SCI treatment utilizing the enhanced outgrowth of axons to restore functional connectivity in SCI patients.
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Affiliation(s)
- Zi-Xing Xu
- Department of Spinal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
- Department of Orthopedics, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian Province, China
- Fujian Provincial Institute of Orthopedics, Fuzhou, Fujian Province, China
| | - Dan Xu
- Fujian Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Fang Fang
- Department of Pharmacology, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Ying-Juan Fan
- Department of Pharmacology, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Bing Wu
- The Central Laboratory, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Yu-Fan Chen
- Department of Spinal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Hao-En Huang
- Department of Spinal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Xin-Hao Huang
- Department of Spinal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
| | - Yue-Hong Zhuang
- Fujian Key Laboratory of Brain Aging and Neurodegenerative Diseases, Fujian Medical University, Fuzhou, Fujian Province, China
| | - Wei-Hong Xu
- Department of Spinal Surgery, The First Affiliated Hospital of Fujian Medical University, Fuzhou, Fujian Province, China
- Department of Orthopedics, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian Province, China
- Fujian Provincial Institute of Orthopedics, Fuzhou, Fujian Province, China
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Chudakova DA, Samoilova EM, Chekhonin VP, Baklaushev VP. Improving Efficiency of Direct Pro-Neural Reprogramming: Much-Needed Aid for Neuroregeneration in Spinal Cord Injury. Cells 2023; 12:2499. [PMID: 37887343 PMCID: PMC10605572 DOI: 10.3390/cells12202499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 10/13/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023] Open
Abstract
Spinal cord injury (SCI) is a medical condition affecting ~2.5-4 million people worldwide. The conventional therapy for SCI fails to restore the lost spinal cord functions; thus, novel therapies are needed. Recent breakthroughs in stem cell biology and cell reprogramming revolutionized the field. Of them, the use of neural progenitor cells (NPCs) directly reprogrammed from non-neuronal somatic cells without transitioning through a pluripotent state is a particularly attractive strategy. This allows to "scale up" NPCs in vitro and, via their transplantation to the lesion area, partially compensate for the limited regenerative plasticity of the adult spinal cord in humans. As recently demonstrated in non-human primates, implanted NPCs contribute to the functional improvement of the spinal cord after injury, and works in other animal models of SCI also confirm their therapeutic value. However, direct reprogramming still remains a challenge in many aspects; one of them is low efficiency, which prevents it from finding its place in clinics yet. In this review, we describe new insights that recent works brought to the field, such as novel targets (mitochondria, nucleoli, G-quadruplexes, and others), tools, and approaches (mechanotransduction and electrical stimulation) for direct pro-neural reprogramming, including potential ones yet to be tested.
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Affiliation(s)
- Daria A. Chudakova
- Federal Center for Brain and Neurotechnologies, Federal Medical and Biological Agency of Russia, 117513 Moscow, Russia
| | - Ekaterina M. Samoilova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
- Federal Research and Clinical Center of Specialised Medical Care and Medical Technologies FMBA of Russia, 115682 Moscow, Russia
| | - Vladimir P. Chekhonin
- Department of Medical Nanobiotechnology of Medical and Biological Faculty, Pirogov Russian National Research Medical University, Ministry of Health of the Russian Federation, 117997 Moscow, Russia
| | - Vladimir P. Baklaushev
- Federal Center for Brain and Neurotechnologies, Federal Medical and Biological Agency of Russia, 117513 Moscow, Russia
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia
- Federal Research and Clinical Center of Specialised Medical Care and Medical Technologies FMBA of Russia, 115682 Moscow, Russia
- Department of Medical Nanobiotechnology of Medical and Biological Faculty, Pirogov Russian National Research Medical University, Ministry of Health of the Russian Federation, 117997 Moscow, Russia
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