Major Points and Findings:
- Background: Traumatic spinal cord injury (SCI) leads to direct and indirect damage to neural tissues. This results in motor and sensory dysfunction, dystonia, and pathological reflexes, culminating in paraplegia or tetraplegia. Despite medical advancements, there are no effective regenerative treatments for SCI.
- Stem Cell Therapy: Stem cell therapy has emerged as a promising treatment for SCI due to its ability to target multiple aspects of the injury and its inherent reactivity benefits. The report reviews various types of stem cells used in SCI therapy:
- Bone marrow mesenchymal stem cells (BM-MSCs)
- Umbilical mesenchymal stem cells (U-MSCs)
- Adipose-derived mesenchymal stem cells (AD-MSCs)
- Neural stem cells (NSCs)
- Neural progenitor cells (NPCs)
- Embryonic stem cells (ESCs)
- Induced pluripotent stem cells (iPSCs)
- Extracellular vesicles (EVs)
- Therapeutic Mechanisms: These stem cells exhibit therapeutic effects through various mechanisms such as cell replacement, nutritional support, scaffolding, and immunomodulation. However, single-cell treatments have shown limited benefits, suggesting that a combined treatment approach might be more effective.
- Spinal Cord Injury Overview: SCI is a significant source of psychological and economic burden. In the U.S., over 1 million people are affected, with around 17,000 new cases each year. Current treatments include spinal decompression surgery, spasticity treatment, and rehabilitation therapy. However, recovery remains limited, emphasizing the need for alternative treatments.
- Cell Therapies: Different cell therapies have shown potential in treating SCI by targeting various aspects of the injury. For instance, BM-MSCs have been found to secrete neurotrophic factors, promote axonal regeneration, reduce inflammation, and improve bladder compliance. U-MSCs can protect neurons, inhibit glial scars, and improve muscle tension and bladder function. AD-MSCs promote cell survival, suppress immune activity, and improve sensory and motor functions.
- Stem Cell Transplantation Strategy: BM-MSCs, which are progenitor cells in adult bone marrow, have shown potential in treating SCI. They can reduce inflammatory reactions, alleviate neuropathic pain, and improve functional recovery. They also play a role in the expansion of neurotrophic factors like nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF).
- Clinical Trials: Some clinical trials have shown improvements in patients with SCI after stem cell therapy. For instance, a study involving cervical SCI patients who received BM-MSCs showed improved upper limb motor function in 6 out of 10 candidates six months post-transplantation.