Restoration of spinal cord injury: From endogenous repairing process to cellular therapy

Spinal cord injury (SCI) disrupts the communication pathways between the brain and the body, impacting sensory, motor, and autonomic nerve functions. Currently, there is no definitive treatment for SCI. However, research is focusing on how cells naturally respond to SCI, such as astrocytes, macrophages/microglia, and oligodendrocytes. By understanding and influencing these cells, some progress has been made in SCI treatment. This review provides a detailed look at these endogenous cells and their mechanisms involved in SCI repair, such as limiting inflammation, protecting the spared spinal cord, enhancing myelination, facilitating neovascularization, producing neurotrophic factors, and differentiating into neural/colloidal cell lines, which provides a solid basis for research strategies for SCI repair.

• 1
  Astrocytes play a controversial role in SCI, with some studies suggesting they create glial scars that inhibit axon regeneration, while others show they can be reprogrammed into neurons to treat SCI.
• 2
  Macrophages/microglia have two phenotypes: M1 type, which is pro-inflammatory and can cause further damage, and M2 type, which is anti-inflammatory and promotes tissue repair. Determining the conditions that will cause the phenotypic flip of M1/M2 macrophages is thus another issue that has to be addressed.
• 3
  Oligodendrocytes, which produce myelin, are crucial for nerve signaling. After SCI, oligodendrocyte death leads to demyelination and loss of sensorimotor function. Preventing oligodendrocyte death or encouraging their differentiation can aid in functional recovery.