Neuropathic pain (NP) occurs when the nerves located either inside or outside of the brain and spinal cord are damaged by a lesion or a condition. To date, pharmacological and surgical treatments to address NP have focused on providing symptomatic relief without treating the underlying cause of the condition. These treatment approaches have not been overwhelmingly successful with over 50% of NP patients attaining adequate pain relief.
Recently, an increasing amount of pre-clinical and clinical research has demonstrated cell transplantation-based therapy for NP to be a promising treatment alternative.
In this review, Yin et al. summarize the use of cell grafts for the treatment of NP, synthesize the latest advances and adverse effects, and discuss possible mechanisms to further the development of cell transplant-based therapies for NP.
Neural stem cells (NSCs) demonstrate the ability to divide, self-renew, and differentiate into neurons, astrocytes, and oligodendrocytes; they are also present in a wide array of tissues throughout the body. Considering they are capable of differentiating into neurons and glial, NSCs are considered an ideal candidate cell for replacing damaged nerve cells and delivering trophic factors to the site of lesions contributing to NP. Additional studies have demonstrated NSCs ability to regenerate nerves, offer neuroprotective effects, and secrete a number of factors that enhance the survival of motor and sensory neurons. NSCs transplantation coils also ease NP caused by peripheral nerve injury, a potential benefit that has been observed in animal models.
Olfactory ensheathing cells (OECs) are glial cells that surround and enclose the olfactory nerve bundle and possess the unique ability to transgress the peripheral nervous system (PNS) and central nervous system (CNS). Considering OECs have been shown to have neuro-regenerative functions, they are also considered to be a good choice for treating nerve injury and NP. Studies using animal models have confirmed that OECs transplantation could promote motor recovery and mitigate pain. Although OECs have good prospects of being used for treating NP, the authors call for additional research with longer observation time to verify their long-term effects and safety.
Mesenchymal stem cells (MSCs) can be obtained from a wide variety of sources and can be induced to differentiate into endoderm, mesoderm, and ectoderm cell lines. MSCs are often used for the treatment of diseases involving neuroinflammatory components and have been shown in animal studies to potentially alleviate NP symptoms.
Other cell therapies currently being evaluated for use as a treatment for NP include bone marrow mononuclear cells, GABAergic cells, and genetically modified cells.
The authors conclude that, despite the small number of clinical studies and the lack of systematic evidence, cell therapy as a treatment alternative for NP should be further explored. Specifically, further research should examine the optimal transplantation route, transplantation timing, number of transplanted cells, and transplantation survival rate.
Source: “Cell therapy for neuropathic pain – Frontiers.” 27 Feb. 2023, https://www.frontiersin.org/articles/10.3389/fnmol.2023.1119223.
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