ABSTRACT
Posttraumatic spinal cord cysts are difficult to treat with medication and surgery. Gene-cell therapy is a promising area of treatment for such patients. However, optimal gene-cell construct for this therapy has not been developed. We investigated the therapeutic efficiency of human olfactory ensheathing cells (OECs) transduced by adenoviral vector encoding the mature form of brain-derived neurotrophic factor (mBDNF) in spinal cord cysts. The adenoviral vectors Ad5/35-CAG-mBDNF and Ad5/35-CAG-Fluc were constructed. Spinal cysts were modeled in female Wistar rats. We selected animals at the early and intermediate stages of recovery with scores to 13 according to the Basso, Beattie and Bresnahan (BBB) scale. The efficiency of therapy was evaluated by BBB tests. No cytotoxicity was detected using the Resazurin/AlamarBlue assay for both vectors at multiplicity of infection (MOIs) of 1, 5, and 25. There was an increase in the proliferation of cells treated with Ad5/35-CAG-mBDNF at MOIs of 5 and 25. The hind limb mobility after the transplantation of Ad5/35-CAG-mBDNF- and Ad5/35-CAG-Fluc-transduced human OECs and nontransduced OECs had approximately the same tendency to improve. Cyst reduction was observed with the transplantation of all the samples. Although Ad5/35-CAG-mBDNF-transduced OECs had high BDNF expression levels in vitro, these cells lacked positive effect in vivo because they did not exhibit significant effect concerning functional test when comparing the groups that received the same numbers of OECs. The therapeutic efficiency of transduced OECs appears to be due to the cell component. The autological and tissue-specific human OECs are promising for the personalized cell therapy. It is extremely important to test new gene-cell constructs based on these cells for further clinical use.
Subject(s)
Cysts , Spinal Cord Injuries , Animals , Cell Transplantation , Cell- and Tissue-Based Therapy , Cysts/metabolism , Cysts/therapy , Female , Humans , Nerve Regeneration , Olfactory Bulb , Rats , Rats, Wistar , Spinal Cord , Spinal Cord Injuries/metabolismABSTRACT
The regeneration of nerve tissue after spinal cord injury is a complex and poorly understood process. Medication and surgery are not very effective treatments for patients with spinal cord injuries. Gene therapy is a popular approach for the treatment of such patients. The delivery of therapeutic genes is carried out in a variety of ways, such as direct injection of therapeutic vectors at the site of injury, retrograde delivery of vectors, and ex vivo therapy using various cells. Recombinant adenoviruses are often used as vectors for gene transfer. This review discusses the advantages, limitations and prospects of adenovectors in spinal cord injury therapy.
ABSTRACT
The pathological processes developing after spinal cord injuries often lead to formation of cysts. Existing surgical and medical methods are insufficient for treatment of post-traumatic spinal cord cysts. One of the emerging tools is cell therapy. Olfactory ensheathing cells (OECs) are perspective cells for cell therapy. In this study, we demonstrated that human OEC transplantation is effective in experimental spinal cysts. For our experiments, we selected animals only at the intermediate stage of recovery with scores from 8 to 13 according to the Basso, Beattie, and Bresnahan (BBB) scale. Cells were transplanted in different quantities (0.75 and 1.5 million) into the fully formed cysts and in the areas of injury without cysts. Improvement of limb mobility after human OEC transplantation into post-traumatic cysts was shown. In the group of rats with cysts, time-dependent increase in the BBB score was observed in subgroups treated with 0.75 and 1.5 million OECs with no statistically significant time-dependent dynamics of BBB values in the control group. When all three subgroups (control and two OEC doses) were compared, the Kruskal-Wallis test showed the presence of differences between subgroups after 1, 3, and 4 weeks of treatment with evidence of divergence increase. There was no statistically significant difference between the two doses of OEC treatment. The human OECs in the experiments without cysts were not effective. It was also shown that PKH26-labeled human OECs survive throughout the experiment and migrate to nearby areas of the cyst. Therefore, it was found that it is effective to transplant human OECs into fully formed cysts. In the future, autologous OECs can be used to personalize the treatment of patients with spinal cysts.
