Effects of FTY720 on Neural Cell Behavior in Two and Three-Dimensional Culture and in Compression Spinal Cord Injury.

Introduction: The present study aimed to evaluate the effects of FTY720 as a neuromodulatory drug on the behaviors of neural stem/progenitor cells (NS/PCs) in two-dimensional (2-D) and three-dimensional (3-D) cultures and in spinal cord injury (SCI). Methods: The NS/PCs isolated from the ganglionic eminence of the 13.5-day old embryos were cultured as free-floating spheres. The single cells obtained from the second passage were cultured in 96-well plates without any scaffold (2-D) or containing PuraMatrix (PM, 3-D) or were used for transplantation in a mouse model of compression SCI. After exposure to 0, 10, 50, and 100 nanomolar of FTY720, the survival, proliferation, and migration of the NS/PCs were evaluated in vitro using MTT assay, neurosphere assay, and migration assay, respectively. Moreover, the functional recovery, survival and migration capacity of transplanted cells exposure to 100 nanomolar FTY720 were investigated in SCI. Results: Cell survival and migration capacity increased after exposure to 50 and 100 nanomolar FTY720. In addition, higher doses of FTY720 led to the formation of more extensive and more neurospheres. Although this phenomenon was similar in both 2-D and 3-D cultures, PM induced better distribution of the cells in a 3-D environment. Furthermore, co-administration of FTY720 and NS/PCs 7 days after SCI enhanced functional recovery and both survival and migration of transplanted cells in the lesion site. Conclusions: Due to the positive effects of FTY720 on the behavior of NS/PCs, using them in combination therapies can be an appealing approach for stem cell therapy in CNS injury.

Local delivery of fingolimod through PLGA nanoparticles and PuraMatrix-embedded neural precursor cells promote motor function recovery and tissue repair in spinal cord injury.

Spinal cord injury (SCI) is a devastating clinical problem that can lead to permanent motor dysfunction. Fingolimod (FTY720) is a sphingosine structural analogue, and recently, its therapeutic benefits in SCI have been reported. The present study aimed to evaluate the therapeutic efficacy of fingolimod-incorporated poly lactic-co-glycolic acid (PLGA) nanoparticles (nanofingolimod) delivered locally together with neural stem/progenitor cells (NS/PCs) transplantation in a mouse model of contusive acute SCI. Fingolimod was encapsulated in PLGA nanoparticles by the emulsion-evaporation method. Mouse NS/PCs were harvested and cultured from embryonic Day 14 (E14) ganglionic eminences. Induction of SCI was followed by the intrathecal delivery of nanofingolimod with and without intralesional transplantation of PuraMatrix-encapsulated NS/PCs. Functional recovery, injury size and the fate of the transplanted cells were evaluated after 28 days. The nanofingolimod particles represented spherical morphology. The entrapment efficiency determined by UV-visible spectroscopy was approximately 90%, and the drug content of fingolimod loaded nanoparticles was 13%. About 68% of encapsulated fingolimod was slowly released within 10 days. Local delivery of nanofingolimod in combination with NS/PCs transplantation led to a stronger improvement in neurological functions and minimized tissue damage. Furthermore, co-administration of nanofingolimod and NS/PCs not only increased the survival of transplanted cells but also promoted their fate towards more oligodendrocytic phenotype. Our data suggest that local release of nanofingolimod in combination with three-dimensional (3D) transplantation of NS/PCs in the acute phase of SCI could be a promising approach to restore the damaged tissues and improve neurological functions.

Ibrutinib reduces neutrophil infiltration, preserves neural tissue and enhances locomotor recovery in mouse contusion model of spinal cord injury.

Following acute spinal cord injury (SCI), excessive recruitment of neutrophils can result in inflammation, neural tissue loss and exacerbation of neurological outcomes. Ibrutinib is a bruton's tyrosine kinase inhibitor in innate immune cells such as the neutrophils that diminishes their activation and influx to the site of injury. The present study evaluated the efficacy of ibrutinib administration in the acute phase of SCI on neural tissue preservation and locomotor recovery. Ibrutinib was delivered intravenously at 3.125 mg/kg either immediately, 12 hours after, or both immediately and 12 hours after SCI induction in adult male C57BL/6 mice. Neutrophil influx into the lesion area was evaluated 24 hours following SCI using light microscopy and immunohistochemistry methods. Animals' body weight changes were recorded, and their functional motor recovery was assessed based on the Basso mouse scale during 28 days after treatment. Finally, spinal cord lesion volume was estimated by an unbiased stereological method. While animals' weight in the control group started to increase one week after injury, it stayed unchanged in treatment groups. However, the double injection of ibrutinib led to a significantly lower body weight compared to the control group at 4 weeks post-injury. Mean neutrophil counts per visual field and the lesion volume were significantly decreased in all ibrutinib-treated groups. In addition, ibrutinib significantly improved locomotor functional recovery in all treated groups, especially in immediate and double-injection groups. Neural tissue protection and locomotor functional recovery suggest ibrutinib treatment as a potent immunotherapeutic intervention for traumatic SCI that warrants clinical testing.