Spinal cord injury (SCI) is an overwhelming neurological disorder that can lead to permanent sensory, motor and autonomic dysfunctions. Approximately 180,000 new individuals suffer SCI every year, with a total of 1.3 million chronic SCI patients worldwide. To date, chronic SCI, especially complete chronic SCI, is still a worldwide challenge without any effective treatment strategy. As for chronic SCI, scar tissue formed in the lesion center was considered the main impediment for axonal regeneration. However, whether the endogenous NSCs could be activated by scar tissue removal is unclear.
Recently, a group led by Prof. DAI Jianwu from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (CAS) and JIANG Xingjun from Xiangya Hospital of Central South University was aimed to explore the problems mentioned above. They performed the first scar tissue removal surgery in the 3rd month and the second in the 6th month after completely removing 1 cm of spinal tissue in canines.
They found that Taxol-modified linear ordered collagen scaffold (LOCS+Taxol) implantation could promote axonal regeneration, neurogenesis, electrophysiological and functional recovery only in canines at the first scar tissue removal surgery, but not in canines at the second scar tissue removal surgery.
Interestingly, they also found that more endogenous NSCs around the injured site could be activated in canines with the first rather than the second scar tissue removal.
Figure 1. Only the first time of scar tissue removal is a key time point for chronic complete SCI repair.
Endogenous NSCs could be intensively activated after the first time of scar tissue removal and contribute to the chronic SCI repair after bio-scaffold implantation, but could not effectively activated after the second time of scar tissue removal nor contribute to chronic SCI repair. (Image by IGDB)
Figure 2. Scar tissue removal activated different amounts of endogenous NSCs in two chronic phases. (A) Schematic illustration of endogenous NSC staining. (B) Nestin antibody staining in adjacent uninjured segments 2 days after the first or second scar tissue removal. (C) Quantitative analysis showed a significant difference in nestin-positive signals in the two chronic phases. (Image by IGDB)
These findings showed that the endogenous NSCs activated by scar tissue removal may bring new hope to patients with severe spinal cord injury. It also provided good technical support for the clinical promotion of functional biomaterial for the treatment of spinal cord injury in the future.
This work entitled “Scar Tissue Removal-Activated Endogenous Neural Stem Cells Aid Taxol-Modified Collagen Scaffolds in Repairing Chronic Long-Distance Transected Spinal Cord Injury” was published in Biomaterials Science on May 28, 2021 (DOI:10.1039/D1BM00449B).
This work was supported by National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Key R&D Program of China and the Jiangsu Key R&D Program.
Contact:
Prof. DAI Jianwu
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
