Distribution of Mesenchymal Stem Cells and Effects on Neuronal Survival and Axon Regeneration after Optic Nerve Crush and Cell Therapy

Abstract

Bone marrow-derived cells have been used in different animal models of neurological diseases. We investigated the therapeutic potential of mesenchymal stem cells (MSC) injected into the vitreous body in a model of optic nerve injury. Adult (3–5 months old) Lister Hooded rats underwent unilateral optic nerve crush followed by injection of MSC or the vehicle into the vitreous body. Before they were injected, MSC were labeled with a fluorescent dye or with superparamagnetic iron oxide nanoparticles, which allowed us to track the cells in vivo by magnetic resonance imaging. Sixteen and 28 days after injury, the survival of retinal ganglion cells was evaluated by assessing the number of Tuj1- or Brn3a-positive cells in flat-mounted retinas, and optic nerve regeneration was investigated after anterograde labeling of the optic axons with cholera toxin B conjugated to Alexa 488. Transplanted MSC remained in the vitreous body and were found in the eye for several weeks. Cell therapy significantly increased the number of Tuj1- and Brn3a-positive cells in the retina and the number of axons distal to the crush site at 16 and 28 days after optic nerve crush, although the RGC number decreased over time. MSC therapy was associated with an increase in the FGF-2 expression in the retinal ganglion cells layer, suggesting a beneficial outcome mediated by trophic factors. Interleukin-1β expression was also increased by MSC transplantation. In summary, MSC protected RGC and stimulated axon regeneration after optic nerve crush. The long period when the transplanted cells remained in the eye may account for the effect observed. However, further studies are needed to overcome eventually undesirable consequences of MSC transplantation and to potentiate the beneficial ones in order to sustain the neuroprotective effect overtime.

Tracking stem cells with superparamagnetic iron oxide nanoparticles: perspectives and considerations

“…The cells were transplanted intramyocardially, and labeled cells could be effectively imaged and tracked by MRI for up to 40 days. 60 Besides those produced for clinical applications, several chemical companies also supply nonclinically approved SPIONs with different size ranges, coatings, and surface functionalities, as recently reviewed by Wang et al 56 Our group has also used a nonclinically approved nanoparticle, FeraTrack (Miltenyi Biotec), to label and track bone marrow-derived mononuclear cells 61,62 and mesenchymal stem cells 63 in different preclinical models of neurologic diseases. We were able to track labeled mononuclear cells after intravitreal injection in a rat model of optic-nerve crush, but 14 days post injection the signal derived from the transplanted cells was almost absent.…”

“…Immunostaining with the antibody anti-Iba1 revealed that the vast majority of the cells found in the vitreous body were negative for Iba1. 63 Recently, Ngen et al proposed and validated a method of dual-contrast with SPIONs and gadolinium chelate. …”

“…123 In our experiments, we also were able to detect SPION-labeled mesenchymal cells after injection of 3×10 6 cells into leg muscle of mice, 15,24 1×10 6 cells into rat striatum, 124 and 5×10 6 rat intravitreally. 63 In addition, using mononuclear cells from bone marrow, we detected SPION-labeled cells after the injection of 10 6 cells into spinal cord 62 and 5×10 6 cells intravitreally. 63 As mentioned above, we could detect cells labeled with fluorescent nanoparticles by in vivo imaging better than cells labeled with SPIONs by MRI in chagasic mouse hearts after systemic injection.…”

“…63 In addition, using mononuclear cells from bone marrow, we detected SPION-labeled cells after the injection of 10 6 cells into spinal cord 62 and 5×10 6 cells intravitreally. 63 As mentioned above, we could detect cells labeled with fluorescent nanoparticles by in vivo imaging better than cells labeled with SPIONs by MRI in chagasic mouse hearts after systemic injection. However, despite the higher sensitivity of the fluorescence-based imaging technique compared to MRI, it is not clinically translatable and has poor spatial resolution and limited penetration depth.…”

Altered expression of microRNAs in the neuronal differentiation of human Wharton’s Jelly mesenchymal stem cells

“…The formation of lipid vacuoles in differentiated adipocytes was evaluated by Oil Red O staining. Osteogenic differentiation and chondrogenic differentiation of WJ-MSCs were performed as previously described [20]. Osteogenic differentiation was demonstrated by calcium deposition in culture with Alizarin Red staining.…”