Transplantation Of Olfactory Ensheathing Cells Research Articles

Features of Remyelination after Transplantation of Olfactory Ensheathing Cells with Neurotrophic Factors into Spinal Cord Cysts.

This paper shows for the first time that co-transplantation of human olfactory ensheathing cells with neurotrophin-3 into spinal cord cysts is more effective for activation of remyelination than transplantation of cells with brain-derived neurotrophic factor and a combination of these two factors. The studied neurotrophic factors do not affect proliferation and migration of ensheathing cells in vitro. It can be concluded that the maximum improvement of motor function in rats receiving ensheathing cells with neurotrophin-3 is largely determined by activation of remyelination.

Transplantation of olfactory ensheathing cells can alleviate neuroinflammatory responses in rats with trigeminal neuralgia

Trigeminal neuralgia (TN) is a common form of facial pain, which primarily manifests as severe pain similar to facial acupuncture and electric shock. Olfactory ensheathing cells (OECs) are glial cells with high bioactivity; these cells are essential for the periodic regeneration of the olfactory nerve and have been utilized for the repair of nerve injuries. A member of the P2X receptor family, P2X7R, is an ion channel type receptor that has been confirmed to participate in various pain response processes. In this study, we transplanted OECs into trigeminal nerve–model rats with distal infraorbital nerve ligation to observe the therapeutic effect of transplanted OECs in rats. Additionally, we utilized the P2X7R-specific inhibitor brilliant blue G (BBG) to study the therapeutic mechanisms of cell transplantation. The facial mechanical pain threshold of these rats significantly increased following cell transplantation. The immunohistochemistry, immunoblotting, and RT-qPCR results demonstrated that the levels of P2X7R, (NOD)-like receptor protein-3 (NLRP3), nuclear factor-κB (NF-κB), interleukin (IL)-1β, and IL-18 in the trigeminal ganglion of rats treated with OEC transplantation or BBG treatment were significantly lower than those in the injured group without treatment. Overall, our results demonstrate that OEC transplantation can alleviate TN in rats, and it can reduce the expression of P2X7R related inflammatory factors in TN rats, reducing neuroinflammatory response in TG.

Spinal cord injury: Olfactory ensheathing cell-based therapeutic strategies.

Spinal cord injury (SCI) is a highly disabling neurological disorder that is difficult to treat due to its complex pathophysiology and nerve regeneration difficulties. Hence, effective SCI treatments are necessary. Olfactory ensheathing cells (OECs), glial cells derived from the olfactory bulb or mucosa, are ideal candidates for SCI treatment because of their neuroprotective and regenerative properties, ample supply, and convenience. Invitro, animal model, and human trial studies have reported discoveries on OEC transplantation; however, shortcomings have also been demonstrated. Recent studies have optimized various OEC transplantation strategies, including drug integration, biomaterials, and gene editing. This review aims to introduce OECs mechanisms in repairing SCI, summarize the research progress of OEC transplantation-optimized strategies, and provide novel research ideas for SCI treatment.

Effect of valproic acid combined with transplantation of olfactory ensheathing cells modified by neurotrophic 3 gene on nerve protection and repair after traumatic brain injury

BackgroundTraumatic brain injury (TBI) often leads to cognitive and neurological dysfunction. Valproic acid (VPA) has a neuroprotective effect in acute central nervous system diseases; the neurotrophin 3 gene (NT-3) can maintain the survival of neurons, and olfactory ensheathing cells (OECs) can promote the growth of nerve axons. This study aimed to evaluate the restorative effect of VPA combined with NT-3 modified OECs (NT-3-OECs) on neurological function after TBI. MethodsThe neurological severity score (NSS) of rats was evaluated on the 1st, 7th, 14th, and 28th day after TBI modeling and corresponding intervention. Hematoxylin-eosin (HE) staining, p75 nerve growth factor receptor (P75), glial fibrillary acidic protein (GFAP), and neurofilament protein (NF)staining, and argyrophilic staining were used to observe the morphology of brain tissue 28 days after modeling. Moreover, TdT-mediated dUTP Nick-End Labeling (TUNEL) was used to detect the apoptosis rate of neurons. The changes in synapses and mitochondria in the injured area were observed by electron microscope. ResultsNT-3-OECs transplantation can increase the content of NT-3 in brain tissue, and NT-3-OECs can survive for >28 days. The NSS score of the TBI-VPA-NT-3-OECs group 28 days after cell transplantation was significantly lower than that of the other model treatment groups (P < 0.05). The morphological structure of the brain tissue was more complete, and the neurofilament fibers were neatly arranged, achieving better results than those of the other groups. The apoptosis rate of nerve cells in the TBI-VPA-NT-3-OECs group was significantly lower than in the other treatment groups (P < 0.05). Furthermore, the number of synapses in the combined intervention group was significantly higher than in the other treatment groups, and the mitochondrial structure was more complete. ConclusionNT-3-OECs have good biological function, and VPA combined with NT-3-OECs transplantation can effectively improve the prognosis of TBI rats.

Curcumin-activated Olfactory Ensheathing Cells Improve Functional Recovery After Spinal Cord Injury by Modulating Microglia Polarization Through APOE/TREM2/NF-κB Signaling Pathway

Transplantation of curcumin-activated olfactory ensheathing cells (aOECs) improved functional recovery in spinal cord injury (SCI) rats. Nevertheless, little is known considering the underlying mechanisms. At the present study, we investigated the promotion of regeneration and functional recovery after transplantation of aOECs into rats with SCI and the possible underlying molecular mechanisms. Primary OECs were prepared from the olfactory bulb of rats, followed by treatment with 1µM CCM at 7–10 days of culture, resulting in cell activation. Concomitantly, rat SCI model was developed to evaluate the effects of transplantation of aOECs in vivo. Subsequently, microglia were isolated, stimulated with 100 ng/mL lipopolysaccharide (LPS) for 24 h to polarize to M1 phenotype and treated by aOECs conditional medium (aOECs-CM) and OECs conditional medium (OECs-CM), respectively. Changes in the expression of pro-inflammatory and anti-inflammatory phenotypic markers expression were detected using western blotting and immunofluorescence staining, respectively. Finally, a series of molecular biological experiments including knock-down of triggering receptor expressed on myeloid cells 2 (TREM2) and analysis of the level of apolipoprotein E (APOE) expression were performed to investigate the underlying mechanism of involvement of CCM-activated OECs in modulating microglia polarization, leading to neural regeneration and function recovery. CCM-activated OECs effectively attenuated deleterious inflammation by regulating microglia polarization from the pro-inflammatory (M1) to anti-inflammatory (M2) phenotype in SCI rats and facilitated functional recovery after SCI. In addition, microglial polarization to M2 elicited by aOECs-CM in LPS-induced microglia was effectively reversed when TREM2 expression was downregulated. More importantly, the in vitro findings indicated that aOECs-CM potentiating LPS-induced microglial polarization to M2 was partially mediated by the TREM2/nuclear factor kappa beta (NF-κB) signaling pathway. Besides, the expression of APOE significantly increased in CCM-treated OECs. CCM-activated OECs could alleviate inflammation after SCI by switching microglial polarization from M1 to M2, which was likely mediated by the APOE/TREM2/NF-κB pathway, and thus ameliorated neurological function. Therefore, the present finding is of paramount significance to enrich the understanding of underlying molecular mechanism of aOECs-based therapy and provide a novel therapeutic approach for treatment of SCI.

Chitosan biomaterial enhances the effect of OECs on the inhibition of sciatic nerve injury-induced neuropathic pain

Neuropathic pain is a common symptom experienced by most clinical diseases at different levels, and its treatment has always been a clinical difficulty. Therefore, it is particularly important to explore new and effective treatment methods. The role of olfactory ensheathing cells (OECs) in nerve injury and pain is recognized by different studies. Our previous study found that transplantation of OECs alleviated hyperalgesia in rats. However, single-cell transplantation lacks medium adhesion and support, and exerts limited analgesic effect. Therefore, on the basis of the previous study, this study investigated the effect of pain relief by co-transplanting OECs with chitosan (CS) (a biological tissue engineering material, as OECs were transplanted into the host medium) to the injured sciatic nerve. The results showed that the pain threshold of sciatic nerve injury of rats was significantly reduced, and the expression level of P2×4 receptor in the spinal cord was significantly increased. While olfactory ensheathing cells combined with chitosan (OECs+CS) transplantation could significantly relieve pain, and the analgesic effect was stronger than that of OECs transplantation alone. OECs+CS transplantation promoted the formation of sciatic nerve remyelination, improved the changes of demyelination, and promoted the repair of sciatic nerve injury more significantly. In addition, the effect of OECs+CS to down-regulate the expression of P2×4 receptor was significantly stronger than that of OECs transplantation, and exerted a better analgesic effect. These data reveal that OECs+CS have a better analgesic effect in relieving neuropathic pain induced by sciatic nerve injury, and provide a new therapeutic strategy for pain treatment.

Constructing and Validating a Network of Potential Olfactory Sheathing Cell Transplants Regulating Spinal Cord Injury Progression.

The pathology of spinal cord injury (SCI), including primary and secondary injuries, primarily involves hemorrhage, ischemia, edema, and inflammatory responses. Cell transplantation has been the most promising treatment for SCI in recent years; however, its specific molecular mechanism remains unclear. In this study, bioinformatics analysis verified by experiment was used to elucidate the hub genes associated with SCI and to discover the underlying molecular mechanisms of cell intervention. GSE46988 data were downloaded from the Gene Expression Omnibus dataset. In our study, differentially expressed genes (DEGs) were reanalyzed using the "R" software (R v4.2.1). Functional enrichment and protein-protein interaction network analyses were performed, and key modules and hub genes were identified. Network construction was performed for the hub genes and their associated miRNAs. Finally, a semi-quantitative analysis of hub genes and pathways was performed using quantitative real-time polymerase chain reaction. In total, 718 DEGs were identified, mainly enriched in immune and inflammation-related functions. We found that Cd4, Tp53, Rac2, and Akt3 differed between vehicle and transplanted groups, suggesting that these genes may play an essential role in the transplantation of olfactory ensheathing cells, while a toll-like receptor signaling pathway was significantly enriched in Gene set enrichment analysis, and then, the differences were statistically significant by experimentally verifying the expression of their associated molecules (Tlr4, Nf-κb, Ikkβ, Cxcl2, and Tnf-α). In addition, we searched for upstream regulatory molecules of these four central genes and constructed a regulatory network. This study is the first to construct a regulatory network for olfactory ensheathing cell transplantation in treating SCI, providing a new idea for SCI cell therapy.

Olfactory ensheathing cells and neuropathic pain.

Damage to the nervous system can lead to functional impairment, including sensory and motor functions. Importantly, neuropathic pain (NPP) can be induced after nerve injury, which seriously affects the quality of life of patients. Therefore, the repair of nerve damage and the treatment of pain are particularly important. However, the current treatment of NPP is very weak, which promotes researchers to find new methods and directions for treatment. Recently, cell transplantation technology has received great attention and has become a hot spot for the treatment of nerve injury and pain. Olfactory ensheathing cells (OECs) are a kind of glial cells with the characteristics of lifelong survival in the nervous system and continuous division and renewal. They also secrete a variety of neurotrophic factors, bridge the fibers at both ends of the injured nerve, change the local injury microenvironment, and promote axon regeneration and other biological functions. Different studies have revealed that the transplantation of OECs can repair damaged nerves and exert analgesic effect. Some progress has been made in the effect of OECs transplantation in inhibiting NPP. Therefore, in this paper, we provided a comprehensive overview of the biology of OECs, described the possible pathogenesis of NPP. Moreover, we discussed on the therapeutic effect of OECs transplantation on central nervous system injury and NPP, and prospected some possible problems of OECs transplantation as pain treatment. To provide some valuable information for the treatment of pain by OECs transplantation in the future.

Transplantation of Cryopreserved Olfactory Ensheathing Cells Restores Loss of Functions in an Experimental Model.

In the past decades, the properties of olfactory ensheathing cells (OECs) have been widely investigated. Studies have shown that transplantation of OECs cultured from the olfactory bulb mediates axonal regeneration, remyelination and restores lost functions in experimental central nervous system (CNS) injury models. Autologously sourcing the cells from the nasal mucosa or the olfactory bulb to treat patients with spinal cord injuries would be ideal, but the cell yield achieved may be inadequate to cover the surface area of the lesions typically encountered in human spinal cord contusion injuries. Therefore, banking allogenic cryopreserved olfactory bulb cells from donors or generating cell lines could provide a marked increase in cell stock available for transplantation. This study is undertaken in two control and two intervention groups. The control groups have lesions alone and lesions with collagen gel but without cells. The intervention groups have either transplantation of primary cultured olfactory bulb OECs (bOECs) encapsulated in collagen gel or cryopreserved bulb OECs (CbOECs) encapsulated in collagen gel. Here, we report that transplantation of cryopreserved rat bOECs encapsulated in collagen restored the loss of function in a vertical climbing test in a unilateral C6-T1 dorsal root injury model. The loss of function returns in 80% of rats with injuries in about 3 weeks comparable to that we observed after transplantation of primary cultured bOECs. The regeneration axons induced by the transplant are identified by neurofilament antibodies and ensheathed by OECs. Our results indicate that cryopreserved OECs retain their properties of inducing axon regeneration and restoring loss of function in the experimental model. This is a step forward to translate the research into future clinical applications.

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

Spinal cord injury (SCI) represents an urgent unmet need for clinical reparative therapy due to its largely irreversible and devastating effects on patients, and the tremendous socioeconomic burden to the community. While different approaches are being explored, therapy to restore the lost function remains unavailable. Olfactory ensheathing cell (OEC) transplantation is a promising approach in terms of feasibility, safety, and limited efficacy; however, high variability in reported clinical outcomes prevent its translation despite several clinical trials. The aims of this position paper are to present an in-depth analysis of previous OEC transplantation-based clinical trials, identify existing challenges and gaps, and finally propose strategies to improve standardization of OEC therapies. We have reviewed the study design and protocols of clinical trials using OEC transplantation for SCI repair to investigate how and why the outcomes show variability. With this knowledge and our experience as a team of biologists and clinicians with active experience in the field of OEC research, we provide recommendations regarding cell source, cell purity and characterisation, transplantation dosage and format, and rehabilitation. Ultimately, this position paper is intended to serve as a roadmap to design an effective clinical trial with OEC transplantation-based therapy for SCI repair.

Transplantation of olfactory ensheathing cells decreases local and serological monocyte chemoattractant protein 1 level during the acute phase of rat spinal cord injury.

Monocyte chemoattractant protein 1 (MCP1) is one of the most upregulated cytokines in the spinal cord and serum throughout acute spinal cord injury (SCI). Olfactory ensheathing cells (OECs) transplantation improves SCI through multiple mechanisms, including immunomodulation. Our study aimed to investigate whether OECs ameliorate acute inflammation after SCI by modulating MCP1 expression. We established a standardized clinically relevant contusion model using the NYU impactor. OECs were administered to the injured spinal cord via microinjection 30 minutes after injury. Rat locomotor functions were assessed by the Basso-Beattie-Bresnahan scale score. Time-course histopathological (H&E and IHC) analyses were performed to record rapid changes in acute inflammation at lesion epicenters. Serum MCP1 level was detected by ELISA assay. BBB scores showed improved locomotor functional recoveries in the OECs transplantation group after SCI ( P < 0.05). Staining of H&E and CD68 illustrated that OECs transplantation attenuated inflammatory response by reducing lesion areas and infiltrating myeloid cell numbers. We further revealed significantly decreased MCP1 levels in the spinal cord and serum after OECs transplantation ( P < 0.05). Noteworthily, distinct expression levels of MCP1 were found in rats undergoing a mild injury (cord impacted from a 10-mm height) compared to the moderate injury (25-mm) group. Our study reports that transplantation of OECs promotes locomotor functional recovery after SCI and alleviates acute inflammation by decreasing local and serological MCP1 levels. We provide preliminary evidence that MCP1 might serve as a potential biomarker to reflect the severity of SCI, which is of great interest in future studies.

The Anti-inflammation Property of Olfactory Ensheathing Cells in Neural Regeneration After Spinal Cord Injury.

Neural regeneration has troubled investigators worldwide in the past decades. Currently, cell transplantation emerged as a breakthrough targeted therapy for spinal cord injury (SCI) in the neurotrauma field, which provides a promising strategy in neural regeneration. Olfactory ensheathing cells (OECs), a specialized type of glial cells, is considered as the excellent candidate due to its unique variable and intrinsic regeneration-supportive properties. In fact, OECs could support olfactory receptor neuron turnover and axonal extension, which is essential to maintain the function of olfactory nervous system. Hitherto, an increasing number of literatures demonstrate that transplantation of OECs exerts vital roles in neural regeneration and functional recovery after neural injury, including central and peripheral nervous system. It is common knowledge that the deteriorating microenvironment (ischemia, hypoxia, scar, acute and chronic inflammation, etc.) resulting from injured nervous system is adverse for neural regeneration. Interestingly, recent studies indicated that OECs could promote neural repair through improvement of the disastrous microenvironments, especially to the overwhelmed inflammatory responses. Although OECs possess unusual advantages over other cells for neural repair, particularly in SCI, the mechanisms of OEC-mediated neural repair are still controversial with regard to anti-inflammation. Therefore, it is significant to summarize the anti-inflammation property of OECs, which is helpful to understand the biological characteristics of OECs and drive future studies. Here, we mainly focus on the anti-inflammatory role of OECs to make systematic review and discuss OEC-based therapy for CNS injury.

Macrophages Treated with VEGF and PDGF Exert Paracrine Effects on Olfactory Ensheathing Cell Function.

Glial cell transplantation using olfactory ensheathing cells (OECs) holds a promising approach for treating spinal cord injury (SCI). However, integration of OECs into the hostile acute secondary injury site requires interaction and response to macrophages. Immunomodulation of macrophages to reduce their impact on OECs may improve the functionality of OECs. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), known for their immunomodulatory and neuroprotective functions, have provided improved outcomes in SCI animal models. Thus, VEGF and PDGF modulation of the SCI microenvironment may be beneficial for OEC transplantation. In this in vitro study, the effect of VEGF and PDGF on macrophages in an inflammatory condition was tested. Combined VEGF + PDGF reduced translocation nuclear factor kappa B p65 in macrophages without altering pro-inflammatory cytokines. Further, the ability of OECs to phagocytose myelin debris was assessed using macrophage-conditioned medium. Conditioned medium from macrophages incubated with PDGF and combined VEGF + PDGF in inflammatory conditions promoted phagocytosis by OECs. The growth factor treated conditioned media also modulated the expression of genes associated with nerve repair and myelin expression in OECs. Overall, these results suggest that the use of growth factors together with OEC transplantation may be beneficial in SCI therapy.

Delayed Xenograft Transplantation of Mouse Olfactory Ensheathing Cells in Adult Rats

Regeneration of the central nervous system after injury using appropriate cells for transplantation is a controversial issue. Accessibility of allograft olfactory ensheathing cells to transplant in the spinal cord of patients is not applicable. Therefore, in this study, an attempt has been made to xenotransplant cells from mouse into a corticospinal tract lesion in a rat in order to achieve a plausible preclinical approach for future application to a clinical study. Adult rats were trained to use their forepaws for retrieving. The dorsal corticospinal tract was lesioned by a stereotactic radio-frequency lesion maker at the level of the first/second cervical segments. Rats that had shown no forepaw retrieval by 8 weeks were xenotransplanted with a suspension of cultured olfactory ensheathing cells derived from the mouse olfactory bulb. Starting between 1 and 3 weeks, 10 rats with transplants bridging the lesion site resumed ipsilateral forepaw reaching. After transplanting cells into the lesion side, the cross and horizontal sections of GFAP and NF staining of 10 animals that have the Directed Forepaw Reaching (DFR) function returned showed the regenerated CST fibers in the lesion area after 8 weeks postoperative. Xenotrasplant of olfactory ensheathing cells from the mouse olfactory bulb into a rat corticospinal tract lesion was promising and positive. Animals that had difficulty in Directed Forepaw Reaching had returned the function 8 weeks postoperatively. Doi: 10.28991/SciMedJ-2022-04-02-01 Full Text: PDF

Olfactory Ensheathing Cells Alleviate Facial Pain in Rats with Trigeminal Neuralgia by Inhibiting the Expression of P2X7 Receptor

Trigeminal neuralgia (TN) is a common facial neuropathic pain that is mainly characterized by spontaneous or induced needling or electric shock pain in the innervation area of the trigeminal nerve. It is also referred to as “the cancer that never dies”. The olfactory ensheathing cell (OEC) is a special glial cell in the nervous system that has a strong supportive function in nerve regeneration. Cell transplantation therapy is a useful treatment modality that we believe can be applied in TN management. In this study, OECs were transplanted into the ligation site of the infraorbital nerve of rats. We found that after the OEC transplantation, mechanical pain threshold in the face of the rats was significantly increased. Western blotting, immunofluorescence assay, and reverse transcription-quantitative polymerase chain reaction were performed on the trigeminal ganglia (TG) of model rats. The results revealed a decrease in the expression of P2X7 receptor (P2X7R) in the trigeminal ganglia. Our findings show that OEC transplantation has a good therapeutic effect on TN in rats, and that can reduce the expression of P2X7R in trigeminal ganglia. Therefore, we think that OEC transplantation may be a suitable treatment for TN.

Neurotrophin-3 Enhances the Effectiveness of Cell Therapy in Chronic Spinal Cord Injuries.

Neurotrophin-3 enhances the effectiveness of human olfactory ensheathing cells in improving hind limb mobility in rats with post-traumatic cysts of the spinal cord. Transplantation of olfactory ensheathing cells into spinal cord cysts reduced their size; neurotrophin-3 did not modulate this effect. Combined preparation of human olfactory ensheathing cells and neurotrophin- 3 can be used in neurosurgery for the treatment of patients with spinal cord injuries.

The promoting effects of activated olfactory ensheathing cells on angiogenesis after spinal cord injury through the PI3K/Akt pathway

ObjectiveThe aim of this study was to investigate the pro-angiogenic potential of olfactory ensheathing cells (OECs) activated by curcumin (CCM) and lipopolysaccharide (LPS) and the possible underlying mechanisms.MethodsVascular endothelial cells or tissues were cultured and treated with conditioned medium (CM) extracted from activated OECs activated through the addition of LPS and CCM or unactivated controls. Concomitantly, the pro-angiogenic potential of OECs was assessed in vitro by aortic ring sprouting assay, endothelial wound healing assay, CCK-8 assay, and tube formation assay. Subsequently, the OECs were co-cultured with endothelial cells to evaluate their promoting effect on endothelial cell proliferation and migration following a mechanical scratch. Moreover, the spinal cord injury (SCI) model in rats was established, and the number of endothelial cells and vascular structure in the injured area after SCI was observed with OEC transplantation. Finally, the underlying mechanism was investigated by western blot analysis of phosphorylated kinase expression with or without the MK-2206 (Akt-inhibitor).ResultThe present results showed that the activated OECs can effectively promote vascular endothelial cells' proliferation, migration, and vessel-like structure formation. Strikingly, several pro-angiogenic growth factors such as VEGF-A and PDGF-AA, which facilitate vessel formation, were found to be significantly elevated in CM. In addition, the PI3K/Akt signaling pathway was found to be involved in pro-angiogenic events caused by activated OEC CM, displaying higher phosphorylation levels in cells. In contrast, the delivery of MK2206 can effectively abrogate all the positive effects.ConclusionsOECs activated by LPS and CCM have a pro-angiogenic effect and can effectively promote angiogenesis and improve the microenvironment at the injury site when transplanted in the injured spinal cord. This potentiated ability of OECs to provide pro-angiogenic effects is likely mediated through the PI3K/Akt pathway.

Transplantation of Olfactory Ensheathing Cells: Properties and Therapeutic Effects after Transplantation into the Lesioned Nervous System

The primary olfactory system (POS) is in permanent renewal, especially the primary olfactory neurons (PON) are renewed with a turnover of around four weeks, even in adulthood. The re-growth of these axons is helped by a specific population of glial cells: the olfactory ensheathing cells (OECs). In the POS, OECs constitute an “open-channel” in which the axons of PON cause regrowth from peripheral nervous system (PNS) to central nervous system (CNS). The remarkable role played by OECs into the POS has led scientists to investigate their properties and potential beneficial effects after transplantation in different lesion models of the CNS and PNS. In this review, we will resume and discuss more than thirty years of research regarding OEC studies. Indeed, after discussing the embryonic origins of OECs, we will describe the in vitro and in vivo properties exert at physiological state by these cells. Thereafter, we will present and talk over the effects of the transplantation of OECs after spinal cord injury, peripheral injury and other CNS injury models such as demyelinating diseases or traumatic brain injury. Finally, the mechanisms exerted by OECs in these different CNS and PNS lesion paradigms will be stated and we will conclude by presenting the innovations and future directions which can be considered to improve OECs properties and allow us to envisage their use in the near future in clinical applications.

Three-dimensional Collagen Scaffolds in Cultures of Olfactory Ensheathing Cells Used for Severed Spinal Cord Regeneration.

The regeneration of a completely damaged spinal cord is still a challenge in modern medicine. A promising treatment method is autologous transplantation of olfactory ensheathing cells (OECs). This study aimed primarily to test methods of culturing OECs with the use of materials and reagents that are certified for pharmaceutical use in the production of an advanced cell therapy product intended for humans. The culture of OECs was performed using various modifications of the surface of the culture vessels (with fibronectin and poly-D-lysine). The number of cells was assessed after immunofluorescence staining using anti-fibronectin and anti-p75 NGF receptor antibodies. The study compared, in terms of surgical manipulations, scaffolds with OECs prepared based on 3 types of collagen: Acid Solubilized Telo Collagen and Pepsin Solubilized Atelocollagen, and the popular Corning collagen. We have shown that when suspending OECs in collagen gel, it is much better to use acid-solubilized collagen (ASC) than pepsin-solubilized collagen (PSC) because the 3D collagen scaffold from ASC provides much easier handling of the product during a surgical procedure. We also found that the OEC cultures should be grown on the surface modified with fibronectin. Furthermore, we have also shown that the optimal concentration of fetal bovine serum (FBS) for culturing these cells should be around 10%. The culture of OECs based on reagents intended for human use can be successfully carried out, obtaining sufficient OECs content in the heterogeneous cell culture to produce a functional advanced therapy medicinal product.

PARTICIPATION OF HUMAN OLFACTORY ENSHEATHING CELLS IN NEUROREGENERATION PROCESSES IN EXPERIMENTAL SPINAL CORD INJURIES

The experimental post-traumatic spinal cord cysts were modeled. The efficiency of transplantation of the human olfactory ensheathing cells into cysts to restore the motor activity of the hind limbs of rats was shown. Survival and migration of ensheathing cells in vivo, their participation in the remyelination were shown.