Transplantation Of Olfactory Ensheathing Cells Research Articles

Transplanted olfactory ensheathing cells reduce the gliotic injury response of Müller cells in a rat model of retinitis pigmentosa

Retinitis pigmentosa leads to progressive visual loss and blindness. Until now there has been no effective therapy. Experimental studies have shown that transplantation of olfactory ensheathing cells into CNS lesions reorganizes the glial scar and stimulates axon regeneration. We now report that cultured syngeneic adult rat olfactory ensheathing cells transplanted into the subretinal space of pigmented Royal College of Surgeon rats survived for a minimum of 8weeks, migrated into surrounding space, and suppressed the gliotic injury response of the Müller cells. Further investigation of intraretinal transplantation of olfactory ensheathing cells may suggest a possible future route for protection of the retina in retinitis pigmentosa.

CNPase Expression in Olfactory Ensheathing Cells

A large body of work supports the proposal that transplantation of olfactory ensheathing cells (OECs) into nerve or spinal cord injuries can promote axonal regeneration and remyelination. Yet, some investigators have questioned whether the transplanted OECs associate with axons and form peripheral myelin, or if they recruit endogenous Schwann cells that form myelin. Olfactory bulbs from transgenic mice expressing the enhanced green fluorescent protein (eGFP) under the control of the 2-3-cyclic nucleotide 3-phosphodiesterase (CNPase) promoter were studied. CNPase is expressed in myelin-forming cells throughout their lineage. We examined CNPase expression in both in situ in the olfactory bulb and in vitro to determine if OECs express CNPase commensurate with their myelination potential. eGFP was observed in the outer nerve layer of the olfactory bulb. Dissociated OECs maintained in culture had both intense eGFP expression and CNPase immunostaining. Transplantation of OECs into transected peripheral nerve longitudinally associated with the regenerated axons. These data indicate that OECs in the outer nerve layer of the olfactory bulb of CNPase transgenic mice express CNPase. Thus, while OECs do not normally form myelin on olfactory nerve axons, their expression of CNPase is commensurate with their potential to form myelin when transplanted into injured peripheral nerve.

Motor recovery following olfactory ensheathing cell transplantation in rats with spinal cord injury

Olfactory ensheathing cells (OEC) are considered to be the most suitable cells for transplantation therapy in the central nervous system (CNS) because of their unique ability to help axonal regrowth and remyelination in the CNS. However, there are conflicting reports about the success rates with OEC. This study was undertaken to evaluate the therapeutic effect of OEC in rat models using different cell dosages. OECs harvested from the olfactory mucosa of adult white Albino rats were cultured. Spinal cord injury (SCI) was inflicted at the lower thoracic segment in a control and test group of rats. Two weeks later, OECs were delivered in and around the injured spinal cord segment of the test group of the rats. The outcome in terms of locomotor recovery of limb muscles was assessed on a standard rating scale and by recording the motor-evoked potentials from the muscles during transcranial electrical stimulation. Finally, the animals were sacrificed to assess the structural repair by light microscopy. Wilcoxon signed rank test and Mann-Whitney U-test were used to compare the data in the control and the test group of animals. A P value of <0.05 was considered significant. The study showed a moderate but significant recovery of the injured rats after OEC transplantation (P=0.005). Transplantation of OECs along with olfactory nerve fibroblasts improved the motor recovery in rat models with SCI.

The effect of olfactory ensheathing cell transplantation combined with walking training on neurofunction recovery in rats after spinal cord contusion

Objective To explore the effect of olfactory ensheathing cell （OEC） transplantation combined with walking training on neurofunction recovery in rats after spinal cord contusion. Methods Forty adult female rats aged （75 ± 1 ） days were subjected to experimental spinal cord contusion at the T10 level using a New York University impactor at a height of 25 mm. They were then divided into 4 groups： （ 1 ） an OEC transplantation combined with walking training （OEC-walking training） group, （2） an OEC transplantation （OEC） group, （3） a walking training combined with Dulbecco＇s modified Eagle medium injection （DMEM） （walking training-DMEM） group, and （4） aDMEM injection （SCI-DMEM） group. The OEC transplants and DMEM injections were performed 2 weeks post-injury. Walking training began at the 7th day post-injury and consisted of daily sessions （once daily, 5 days a week for 10 weeks） of quadrupedal treadmill training, starting from 15 min and gradually increasing to 30 min daily, at speeds starting from 3 m/min and gradually increasing in accordance to the condition of the rats. Locomotor function recovery of the rats＇ hindlimbs was evaluated weekly using the Basso, Beattie and Bresnahan （BBB） locomotor rating scale.The expression of tyrosine hydroxylase （ TH ） was detected in the injured region of the lumbar spinal cord. Results The BBB scores of rats in the OEC-walking training group and the walking training-DMEM group improved significantly from the 4th week post-injury compared to the SCI-DMEM injection group. Rats in the OEC transplantation group had a significant improvement in BBB scores at the 5th to 8th weeks post-injury. At the end of the 11th week post-injury, the average BBB scores were 13.14 ± 0.24 in the OEC-walking training group, 11. 64 ± 0.56 in the OEC transplantation group, 12.29 ±0.64 in the walking training-DMEM group and 11.07 ± 0.84 in the SCI-DMEM group.The OEC-walking training group scored significantly higher than the other 3 groups. Although the number of TH-positive neurons in the lumbar spinal cord was not significantly different among the groups, the morphology of TH-positiveneurons in the OEC-walking training group and the walking training-DMEM group was different from those in the OEC transplantation group and the SCI-DMEM group. Conclusions OEC transplantation combined with walking training can effectively promote the functional recovery of the hindlimb. The plasticity of the descending TH system and of motoneurons of the ventral horn of the lumbar spinal cord might mediate the changes. Key words: Spinal cord contusion; Olfactory ensheathing cells transplantation; Walking training; Neurofunction; Tyrosine hydroxylase

Neutralization of BDNF attenuates the in vitro protective effects of olfactory ensheathing cell-conditioned medium on scratch-insulted retinal ganglion cells.

Transplantation of olfactory ensheathing cells (OECs) becomes one of the promising strategies in restoring lost functions of injured central nervous system. Elevated level of expressed brain-derived neurotrophic factor (BDNF) was revealed in the previous studies to be related to the protective effects of OECs on injured cortical and brain stem neurons as well as retinal ganglion cells (RGCs), but no evidence has been obtained to demonstrate whether transplanted OECs protect injured central neurons directly by their secreted BDNF. In the present study, the effects of BDNF neutralization on the neuroprotection of adult OEC-conditioned medium (OEC-CM) on scratch-insulted RGCs were examined. The results showed that OEC-CM protected cultured RGCs from scratch insult, and neutralization of BDNF by BDNF neutralizing antibody attenuated such neuroprotection of the medium. It is thus concluded that neurotrophic factors including BDNF secreted by OECs can protect injured OECs in vitro and BDNF plays a major role in such a protection of OECs.

Olfactory ensheathing cells enhance Schwann cell-mediated anatomical and functional repair after sciatic nerve injury in adult rats

Sciatic nerve injury results in axon damage, muscle degeneration, and loss of function. We compared the potential of Schwann cell (SC), olfactory ensheathing cell (OEC), or mixed SC/OEC transplants for anatomical and functional restoration after adult rat sciatic nerve transection. The cells were seeded into a 20mm long macroporous poly(dl-lactide-co-glycolide) acid conduit and grafted between the sciatic nerve stumps. Some rats received a conduit without cells (controls) or an autologous nerve graft, the clinical standard of care. Compared with SC transplants, axon regeneration was 25% less with OEC transplants but 28% more with SC/OEC transplants. Gastrocnemius muscle restoration was similar with a SC or OEC transplant and 35% better with a SC/OEC transplant. With SC transplants, motor and sensory function recovery and electrophysiological outcomes were similar as with OEC transplants and 33% better with SC/OEC transplants. Compared with the mixed SC/OEC transplants, axon regeneration was 21% better and gastrocnemius muscle restoration was 18% better with autologous peripheral nerve transplants, but these improvements did not translate into increased function and electrophysiological outcomes. Our results revealed that OEC synergistically improve SC mediated sciatic nerve repair. The data emphasized the promise of SC/OEC transplants as artificial nerves for peripheral nerve repair. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair.

Cellular transplants in amyotrophic lateral sclerosis patients: an observational study

Cytotherapy is a promising option for neurodegenerative disease treatment. Because of the fatal prognosis and imperative need for effective treatment, amyotrophic lateral sclerosis (ALS) patients request this therapy before its effectiveness has been verified. The increase in clinics offering cytotherapies but providing little scientific information has prompted considerable medical tourism. We present an observational study of Spanish ALS patients receiving cytotherapy, analyzing the experiences arising from the treatment (TX) and considering two progression markers, FVC and ALSFRS-R. Twelve ALS patients with a mean age of 48.6 years (SD 12.8) received cytotherapy 26.9 months (SD 15.8) after clinical onset. ALSFRS-R and FVC at TX were 32.3 (SD 6.8) and 63.4% (SD 15.3), respectively. TX involved transplants of olfactory ensheathing cells in three patients, and autologous mesenchymal stromal cells in the remainder. One patient died 33 months post-TX after surviving for 49 months. Five required mechanical non-invasive home ventilation 7.4 months post-TX. Two required invasive ventilation 13 months post-TX. Five patients needed gastrostomy feeding 23.3 months post-TX. Survival between clinical onset and the study end date was 50 months (SD 17.2). No significant adverse events or changes in the decline of FVC and ALSFRS-R compared with the disease's natural history were observed. Our observations suggest that these therapies do not halt the course of the disease. Cytotherapy cannot yet be considered a curative treatment for ALS.

Diffusible, membrane-bound, and extracellular matrix factors from olfactory ensheathing cells have different effects on the self-renewing and differentiating properties of neural stem cells

Transplantation of olfactory ensheathing cells (OECs) has been a promising strategy in enhancing central nervous system (CNS) regeneration. However, little is known about the effects of transplanted OECs on the self-renewal, neurogenesis, and oligodendrogenesis of neural stem cells (NSCs), which are known to play a very important role in the repair of damaged CNS tissue. In this study, we investigated the influence of diffusible, membrane-bound, and extracellular matrix factors from OECs on the self-renewal and differentiation properties of NSCs. We found that diffusible factors from cultured OECs promoted self-renewal, whereas the extracellular matrix molecules from OECs increased neurogenesis and oligodendrogenesis of NSCs. Furthermore, we demonstrated that directly coculturing OECs and NSCs inhibited not only self-renewal but also neurogenesis and oligodendrogenesis of NSCs. We propose three models for the interaction between transplanted OECs and endogenous NSCs. Our findings provide new insight into the ability of OECs to promote CNS repair and also indicate potential targets for manipulation of these cells to enhance their restorative ability.

Combination of olfactory ensheathing cells with local versus systemic cAMP treatment after a cervical rubrospinal tract injury

The failure of CNS axons to regenerate following traumatic injury is due in part to a growth-inhibitory environment in CNS as well as a weak intrinsic neuronal growth response. Olfactory ensheathing cell (OECs) transplants have been reported to create a favorable environment promoting axonal regeneration, remyelination, and functional recovery after spinal cord injury. However, in our previous experiments, OEC transplants failed to promote regeneration of rubrospinal axons through and beyond the site of a dorsolateral funiculus crush in rats. Rubrospinal neurons undergo massive cell atrophy and limited expression of regeneration-associated genes after axotomy. Using the same injury model, we tested the hypothesis that treatment of the red nucleus with cAMP, known to stimulate the intrinsic growth response in other neurons, will promote rubrospinal regeneration in combination with OEC transplants. In addition, we assessed a systemic increase of cAMP using the phosphodiesterase inhibitor rolipram. OECs prevented cavity formation, attenuated astrocytic hypertrophy and the retraction of the axotomized rubrospinal axons, and tended to reduce the overall lesion size. OEC transplantation lowered the thresholds for thermal sensitivity of both forepaws. None of our treatments, alone or in combination, promoted rubrospinal regeneration through the lesion site. However, the systemic elevation of cAMP with rolipram resulted in greater numbers of OECs and axonal density within the graft and improved motor performance in a cylinder test in conjunction with enhanced rubrospinal branching and attenuated astrocytic hypertrophy.

Survival of retinal ganglion cells in slice culture provides a rapid screen for olfactory ensheathing cell preparations

Transplants of olfactory ensheathing cells (OECs) cultured from the olfactory bulb are able to induce structural regeneration of severed central axons and return of function in rat models. For clinical purposes it would be preferable to obtain the cells from the more accessible olfactory mucosa in the nasal lining. However, in our laboratory preparations cultures from mucosal samples yielded around 5% of OECs compared with the 50% obtained from samples cultured from the bulb, and when transplanted these mucosal cell preparations were less effective at repair. There are a number of manipulations which may increase the OEC content and the effectiveness of mucosal preparations, but in vivo transplantation would be a highly labour intensive method for evaluating them. As a candidate for a high throughput assay to screen for beneficial effects of modifications to mucosal cells we here report the effects of co-culture of the cells with retinal explants. Both bulbar and mucosal cell preparations prolong the survival of the explants. Counts of the surviving retinal ganglion cells, identified by β-III-tubulin immunohistochemistry and by their axon trajectory, show that the bulbar cell preparations have around twice the potency of those from the mucosa. This in vitro system, therefore, provides a bioassay that discriminates bulbar and mucosal cell preparations, and a useful tool for evaluating the functional effects of manipulations of cultured mucosal preparations.

The olfactory ensheathing cells transplantation for traumatic brain injury recovery of nerve function and its mechanism

Objective To observe olfactory ensheathing cells transplantation on brain injury recovery nerve function and to explore its mechanism. Methods After purification of the olfactory ensheathing cells cultured for NGFRp75 immunocytochemical identification and preparation of cell suspension for transplantation, some cells were pre-labeled for bservation of survival after transplantation. 48 adult SD rats were randomly divided into three groups:sham operation without injury group (A group),cerebral cortex motor area injury group (B group) , the same brain injury and the olfactory ensheathing cell transplantation group (C group). At postoperative day,3 d, 7 d,14 d the neurological severity score (NSS) of rats were assessed; 14 d after injury of brain tissues were taken for NeuN immunohistochemistry host the number of neurons change. The data were statistically analyzed using SPSS17.0 software. Results (1) Cultured olfactory ensheathing cells showed NCFRp75 positive,the positive rate was 90%. (2) 14 d after transplantation of nuclear fluorescence labeling of olfactory ensheathing cells survived well in the host body. (3) 14 d after NSS score of B group( 2.00 ± 0.53) and C group ( 1.25 ± 0.46) were significantly better than the B group (P<0.05). (4) NeuN positive cells in B group (39.2 ±7. 1) and C group(45, 8 ± 6.0) were significantly better than B group (P<0.05). Conclusions Olfactory ensheathing cell transplantation can promote the recovery of neurological function in rats brain injury,which may be related with olfactory ensheathing cells to promote neuron survival in the host. Key words: Olfactory ensheathing cells; Traumatic brain injury; Cell transplantation; Neurological function recovery; Neuronal survival

Delayed olfactory ensheathing cell transplants reduce nociception after dorsal root injury

Injury to cervical dorsal roots mimics the deafferentation component of brachial plexus injury in humans, with intractable neuropathic pain in the deafferented limb being a common consequence. Such lesions are generally not amenable to surgical repair. The use of olfactory ensheathing cells (OECs) for dorsal root repair, via acute transplantation, has been successful in several studies. From a clinical point of view, delayed transplantation of OECs would provide a more realistic timeframe for repair. In this study we investigated the effect of delayed OEC transplantation on functional recovery of skilled forepaw movements and amelioration of neuropathic pain, using a C7 and C8 dorsal root injury rat model previously established in our lab. We found that OEC transplantation to the dorsal horn 1week after root injury effectively attenuated neuropathic disturbances associated with dorsal root injury, including spontaneous pain behavior, tactile allodynia and thermal hyperalgesia. The sensory controls of complex, goal-oriented skilled reaching and ladder walking, however, were not improved by delayed OEC transplantation. We did not detect any significant influence of transplanted OECs on injury-induced central reorganisation and afferent sprouting. The anti-nociceptive effect mediated by OEC transplants may therefore be explained by alternative mechanisms such as modification of inflammation and astrogliosis. The significant effect of OEC transplants in mitigating neuropathic pain may be clinically useful in intractable pain syndromes arising from deafferentation. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair.

Nasal OEC transplantation promotes respiratory recovery in a subchronic rat model of cervical spinal cord contusion

Engraftment of nasal olfactory ensheathing cells (OEC) is considered as a promising therapeutic strategy for spinal cord repair and one clinical trial has already been initiated. However, while the vast majority of fundamental studies were focused on the recovery of locomotor function, the efficiency of this cellular tool for repairing respiratory motor dysfunction, which affects more than half of paraplegic/tetraplegic patients, remains unknown. Using a rat model that mimics the mechanisms encountered after a cervical contusion that induces a persistent hemi-diaphragmatic paralysis, we assessed the therapeutic efficiency of a delayed transplantation (2weeks post-contusion) of nasal OECs within the injured spinal cord. Functional recovery was quantified with respiratory behavior tests, diaphragmatic electromyography and neuro-electrophysiological recording of the phrenic motoneurons while axogenesis was evaluated using immunohistochemistry. We show that 3months post-transplantation, nasal OECs improve i) breathing movements, ii) activities of the ipsilateral diaphragm and corresponding phrenic nerve, and iii) axonal sprouting in the injury site. We also demonstrate that this functional partial recovery is mediated by the restoration of ipsilateral supraspinal command. Our study brings further evidence that olfactory ensheathing cells could have clinical application especially in tetraplegic patients with impaired breathing movements. This article is part of a Special Issue entitled: Understanding olfactory ensheathing glia and their prospect for nervous system repair.

Selected changes in spinal cord morphology after T4 transection and olfactory ensheathing cell transplantation

Spinal cord transection at T4 results in severe damage of the nervous tissue, with impairment of motor, sensory and autonomic functions. Transplantation of olfactory ensheathing cells (OECs) has the potential to improve these functions through a number of mechanisms, which include facilitation of regeneration and neuroprotection. For cardiovascular functions, we have previously shown that OECs reduce the duration of autonomic dysreflexia, without evidence of regeneration. To further understand the mechanisms underpinning this improvement, we have studied changes in selected morphological features (cavitation, non-cavity tissue loss, morphology of sympathetic preganglionic neurons and primary afferent fibre density) in the T4-transected rat spinal cord over 9 weeks, both in control and OEC-transplanted animals. T4 transection led to a number of structural changes: gradual formation of cavities, non-cavity tissue loss, a long-term increase in soma size of sympathetic preganglionic neurons and a temporary increase in the extent of their dendritic arbours, and an increase in the density of primary afferent fibres caudal to the lesion. OECs decreased the cavitation and normalised soma size of the sympathetic preganglionic neurons below the lesion, while increasing the extent of dendritic arbours in the preganglionic neurons above the lesion. Thus the OECs may contribute to the normalisation of the dysreflexic hypertension through tissue preservation and normalisation of the morphology of the preganglionic neurons caudal to the lesion, while enhancing the input on the rostral preganglionic neurons, whose vasomotor control remains intact. We hypothesise that these changes are mediated through secretion of soluble trophic factors by the transplanted OECs.

Olfactory Mucosal Transplantation After Spinal Cord Injury Improves Voiding Efficiency by Suppressing Detrusor-Sphincter Dyssynergia in Rats

Several recent studies showed that olfactory mucosal transplantation after spinal cord injury promotes extensive regeneration of the injured spinal cord. We examined the efficacy of olfactory mucosal transplantation for bladder dysfunction after spinal cord injury in rats. In adult female rats the Th9-10 spinal cord was completely transected, followed by olfactory mucosal transplantation or gelatin sponge filling as the control. Each group was examined by cystometrogram and external urethral sphincter electromyogram. Calcitonin gene-related peptide and growth associated protein 43 double positive expression in the L6/S1 dorsal horn was evaluated by immunohistochemistry. Transplant sites were examined by immunohistochemistry with antibodies against neurofilament M and neuronal class III beta-tubulin. On cystometrogram voiding efficiency was significantly higher in the transplantation group than in controls. On external urethral sphincter electromyogram with simultaneous cystometrogram the transplantation group showed a larger ratio of interburst silent periods to burst activity duration and a greater number of high frequency oscillations. In the transplantation group calcitonin gene-related peptide and growth associated protein 43 double positive expression in the L6/S1 dorsal horn was less dense than in controls. The transplantation group showed strong neurofilament M and neuronal class III beta-tubulin expression at the transplant site. Olfactory mucosal transplantation after spinal cord injury weakened external urethral sphincter excessive bursting and increased the urethral opening to improve voiding efficiency. Olfactory mucosal transplantation may modify emergence of the spinal micturition reflex after spinal cord injury. Transplantation resulted in new axons growing at the transplant site, implying the possible existence of interneuron bridging across the injured spinal cord.

Reaction of Oligoglia to Spinal Cord Injury in Rats and Transplantation of Human Olfactory Ensheathing Cells

In experiments on rats with lateral TVIII hemisection of the spinal cord and transplantation of ensheating olfactory cells, we studied structural changes at the lesion site and adjacent rostral and dorsal regions of the spinal cord. The state of oligodendrocytes and myelin fibers and motor function in experimental animal were analyzed. Open field testing (BBB test) showed that motor functions steadily increased (by 13% on average) within the interval from day 21 to day 53 after transplantation. Histological examination showed that groups of transplanted cells carrying human nuclear marker (HNu(+)cells) were still present at the lesion site 30 days after surgery. Some of these cells migrated in the rostral and caudal directions from the injection site to a distance up to 6 mm. At the initial period after hemisection, the number of oligodendrocytes (O4(+)-cells) in the immediate vicinity to the lesion site decreased 2-fold, but no significant changes in the number of neurons were found in the rostral and dorsal fragments of the spinal cord compared to the corresponding parameter in controls. Sixty days after transplantation, the cross-section area in the rostral part of the spinal cord at a distance of 3 mm from damage site increased by 15.3% compared to the control. The number of O4(+)-cells at the lesion site and in adjacent rostral and caudal parts of the spinal cord by 22.8% surpassed that in the control group. The number of remyelinated axons also increased. These findings suggest that the absence of pronounced structural changes in the rostral and caudal parts of the spinal cord compared to lesion site at early stages after damage and cell transplantation. At the same time, pronounced activation of oligodendrocytes in this region suggests their involvement together with Schwann cells into remyelination of regenerating axons, which can serve as a factor of partial restoration of motor functions after spinal cord injury.

Survival-enhancing of spiral ganglion cells under influence of olfactory ensheathing cells by direct cellular contact

The efficacy of cochlear implantation is primarily associated with the quantity and health of the remaining spiral ganglion cells (SGCs). Olfactory ensheathing cells (OECs) are capable of expressing a variety of growth factors and adhesion molecules, playing an important role in enhancing cellular survival. To investigate the effect of OECs on the survival of SGCs, co-cultures of OECs and SGCs were developed in this study. In addition, OECs conditioned medium (OEC-CM) was employed to culture SGCs in contrast with the co-cultures. OECs were identified immunocytochemically by low-affinity nerve growth factor receptor p75 (P75NTR) and glial fibrillary acidic protein (GFAP), while SGCs were stained with neuron-specific markerβIII-tubulin. SGCs survival was assessed in different conditions. To explore the underlying mechanism, growth factors, adhesion molecules and their receptors were investigate using RT-PCR. Our results indicate that the co-cultures of OECs and SGCs can be successfully established and that both OECs and OEC-CM promote SGCs survival in vitro. SGCs survival was most enhanced when co-cultured with OECs. Both Olfactory bulb (OB) and OECs were proved to express BMP-4 and NCAM while BMPR-1A and a7 integrin were also detected in cochlea and SGCs. In conclusion, our results suggest that enhancement in co-cultures is in part due to direct cellular contact. Transplantation of OECs may be a cell-based therapy for the application of neurotrophic factors to the inner ear.

Effects of human OEC-derived cell transplants in rodent spinal cord contusion injury

Numerous reports indicate that rodent olfactory ensheathing cells (OECs) assist in spinal cord repair and clinical trials have been undertaken using autologous transplantation of human olfactory ensheathing cells (hOECs) as a treatment for spinal cord injury. However, there are few studies investigating the efficacy of hOECs in animal models of spinal cord injury. In this study hOECs were derived from biopsies of human olfactory mucosa, purifed by culture in a serum-free medium containing neurotrophin-3, genetically labelled with EGFP, and stored frozen. These hOEC-derived cells were thawed and transplanted into the spinal cord injury site 7 days after a moderate contusion injury of the spinal cord at thoracic level T10 in the athymic rat. Six weeks later the animals receiving the hOEC-derived transplants had greater functional improvement in their hindlimbs than controls, assessed using open field (BBB scale) and horizontal rung walking tests. Histological analysis demonstrated beneficial effects of hOEC-derived cell transplantation: reductions in the volume of the lesion and the cavities within the lesion. The transplanted cells were located at the periphery of the lesion where they integrated with GFAP-positive astrocytes resulting in a significant reduction of GFAP staining intensity adjacent to the lesion. Although their mechanism of action is unclear we conclude that hOEC-derived cell transplants improved functional recovery after transplantation into the contused spinal cord, probably by modulating inflammatory responses and reducing secondary damage to the cord.

Ginsenoside Rg1 promotes proliferation and neurotrophin expression of olfactory ensheathing cells

Transplantation of olfactory ensheathing cells (OECs) is currently considered to be one of the most promising repair strategies for human spinal cord injury. However, the factors that regulate OECs are still poorly understood. Ginsenoside Rg1 (Rg1), the phytosterol from Panax ginseng, is a potent neuroprotective agent that promotes axonal regeneration. The aim of this study is to determine whether Rg1 would influence the biological activity of OECs. Primary cultured OECs from the olfactory bulb of neonatal rats were treated with Rg1 of various concentrations and durations. Using MTT and bromodeoxyuridine assays, we found that Rg1 significantly promoted cell proliferation, with an optimal concentration of 40 μg/ml of Rg1 at 72 h. In addition, RT-PCR and ELISA assays showed that Rg1 could upregulate the mRNA expression and secretion of glial cell-derived neurotrophic factor, brain-derived neurotrophic factor, and nerve growth factor. These results suggest that Rg1 may have a great potential in OEC therapy.

Olfactory ensheathing cells (OECs) transplantation in spinal cord prolongs the survival of mutant SOD1 (G93A) ALS rats through neuroprotection and remyelination

Amyotrophic lateral sclerosis (ALS) is a fatal progressive neurodegenerative disease. SOD1G93A rat(n=20), medium+SOD1G93A rat(n=20), OECs+SOD1G93A rat(n=20), and another 20 wild type rats as control. 5μL(1×105) OECs was injected into the dorsal funiculus of the thoracic spinal cord (T7) through a glass micropipette at depths of 0.7 mm and 0.4 mm (0.5 lL). Kaplan Meier survival analysis revealed a significant increase (7 days) in the survival time of the OEC+SOD1G93A rats. Body weight record and Inclined board test showed a significant difference from onset 7days to 11days (P&lt;0.05). Motor neuron count per ventral horn of thoracic spinal cord showed a significant motor neuron loss in SOD1G93A rats(P&lt;0.001). Immunohistochemistry and Western blot ChAT analysis supported the motor neuron count. Confocal microscope images of tissue sections indicated that the transplanted OEC could have survived more than four weeks and migrated as long as 8.4mm through the spinal cord. Evidence of remyelination was captured. In conclusion, the transplanted OECs could serve as a source of neuroprotection and a remyelination to positively modify the ALS‐specific microenvironment.