Why is olfactory neuroepithelium?

Abstract

Currently, most cellular therapeutic effects for nervous diseases cannot be proven in a multicenter, randomized, double-blind placebo-control clinical trials, except for a few kinds of cells such as olfactory ensheathing cells. These cells show significant improvements in functional recovery and quality of life for patients with chronic ischemic stroke. Also, olfactory neuron transplantation has promising neurorestorative effects on patients with vascular dementia. Human olfactory neuroepithelium can spontaneously and sustainably regenerate or produce new olfactory neurons and glial cell types for decades or a lifetime. The neurorestorative mechanisms of olfactory ensheathing cells are well known; however, little is known about the neurorestorative mechanisms of olfactory neurons. Therefore, I hypothesize that the neurorestorative mechanisms of olfactory neurons after transplantation: (1) can well migrate where they are needed and become local functional neurons, as they need to compensate or replace; (2) must be regulated by some special molecular factors to elongate their axons, modulate or direct synapses to correctly recognize and connect the target cells, and integrate functions. Based on olfactory neuroepithelium cells displaying the special characterization, neurorestorative mechanisms, clinical therapeutic achievements, and hypotheses of effective mechanisms, they (olfactory ensheathing cells and olfactory neurons) may be the most efficient instruments of neurorestoration.

Recovering Voiding and Sex Function in a Patient with Chronic Complete Spinal Cord Injury by Olfactory Ensheathing Cell Transplantation

“…OECs are special glial cells sharing the characteristic of Schwann cell and astrocyte properties. Their neurorestorative mechanisms include neuroprotection, axonal regeneration, remyelination, neural network or circuitry reconstruction, neuroplasticity, neuromodulation, anti-inflammatory response or immunomodulation, promoting neurogenesis, stimulating angiogenesis, and so on [ 23 ]. There is no barrier for OECs between the central nervous system and peripheral nervous system.…”

Clinical results of neurorestorative cell therapies and therapeutic indications according to cellular bio-proprieties

“…Human adult olfactory neurons are special cells which can automatically regenerate. After being transplanted, they seem to migrate where they are needed, and become local functional neurons as they need to be compensated or replaced [ 114 ]; so the indications of human olfactory neuron therapy should be neurological diseases in which many neurons are lost or die and neurological functions are impaired, such as dementia, PD, etc. Pilot clinical studies demonstrated that patients with PD and VD got benefits from the human olfactory neuron therapy [ 9 , 10 ].…”

“…Exogenous oligodendrocytes may not be strong enough to restore damaged neurological functions/structures. OECs display Schwann cell and astrocyte properties, which demonstrated neurorestorative effects in patients with chronic ischemic stroke through a multicenter, randomized, double blind, placebo-controlled clinical trial [ [4] , [114] ]. OECs can migrate well between CNS and peripheral nervous system.…”

SARS-CoV-2 and Brain Health: New Challenges in the Era of the Pandemic

“…Viruses have the ability to disseminate through the infection of sensory or motor nerve endings, employing retrograde or anterograde neural transport systems supported by motor proteins such as dynein and kinesins [53]. Olfactory neuron transport is an example of a neuronal pathway [2,60]. In the peripheral nervous system (PNS), the olfactory nerve is the primary pathway through which the SARS-CoV-2 virus infiltrates the CNS.…”