Olfactory Ensheathing Cells for Spinal Cord Injury: The Cellular Superpowers for Nerve Repair

Abstract

Neurotrauma injuries are notoriously difficult to deal with both clinically as well as experimentally, as the cellular and molecular events ensuing after injury complicate the neuroinflammatory processes. Spinal cord injuries are further complicated by the formation of scars at the injury sites, which can provide a physical barrier to repair. The lack of effective clinical therapy for spinal cord injury underscores the need for experimental approaches to generate effective therapies. To repair the injury, cell transplantation offers the potential to replace lost cells and create a permissive bridge to promote neural regeneration across the injury site. Olfactory ensheathing cells (OECs), which are the glia of the olfactory nerve, stand apart from other candidate cell types due to their innate natural abilities to manage nerve injury and promote repair and regeneration. This is evidenced by their physiological role in the daily repair and maintenance of the olfactory nerve. Here, we explain their properties in relation to their physiological role and their most relevant cellular attributes, including cellular interactions, phagocytosis, migration, axonal guidance and support, and modulation of neuroinflammation. We highlight some critical drawbacks in the current approaches and identify some ways to address them.

The Promising Role of a Zebrafish Model Employed in Neural Regeneration Following a Spinal Cord Injury

“…Other studies have shown the presence of unidentified cell populations involved in SCI repair in addition to NSCs or stem-like cells with a differentiation capacity [ 59 , 60 ]. Therefore, recent studies have reported mixed cell populations that may participate in nerve regeneration, including Schwann cells [ 61 ], olfactory ensheathing cells [ 62 ], and neurotrophin-expressing fibroblasts, such as BDNF and NT-3 [ 63 ]. At present, however, a definitive analysis of cell populations engaged in nerve regeneration is difficult for two reasons.…”

Designing a Clinical Trial with Olfactory Ensheathing Cell Transplantation-Based Therapy for Spinal Cord Injury: A Position Paper

“…The biological approaches offer the opportunity to replace the lost neural tissue mass and mitigate the damage by shrinking the defect size. Out of all the stem and non-stem cell types explored for cell transplantation, olfactory ensheathing cells (OECs) stand out as promising candidates for neural repair due to their unique properties [ 12 , 13 ]. The OECs are the primary glial cells of the olfactory nerve, where they play a crucial role in replacing up to 1–3% of olfactory neurons daily and guide them to their intended targets in the olfactory bulb throughout life [ 14 ].…”