The ability of a novel intranasally delivered amnion cell derived biologic to suppress inflammation, prevent neuronal damage and preserve neurologic function in the experimental autoimmune encephalomyelitis animal model of multiple sclerosis was assessed. Currently, there are no existing optic nerve treatment methods for disease or trauma that result in permanent vision loss. Demyelinating optic nerve inflammation, termed optic neuritis, induces permanent visual dysfunction due to retinal ganglion cell damage in multiple sclerosis and experimental autoimmune encephalomyelitis. ST266, the biological secretome of Amnion-derived Multipotent Progenitor cells, contains multiple anti-inflammatory cytokines and growth factors. Intranasally administered ST266 accumulated in rodent eyes and optic nerves, attenuated visual dysfunction, and prevented retinal ganglion cell loss in experimental optic neuritis, with reduced inflammation and demyelination. Additionally, ST266 reduced retinal ganglion cell death in vitro. Neuroprotective effects involved oxidative stress reduction, SIRT1-mediated mitochondrial function promotion, and pAKT signaling. Intranasal delivery of neuroprotective ST266 is a potential novel, noninvasive therapeutic modality for the eyes, optic nerves and brain. The unique combination of biologic molecules in ST266 provides an innovative approach with broad implications for suppressing inflammation in autoimmune diseases, and for preventing neuronal damage in acute neuronal injury and chronic neurodegenerative diseases such as multiple sclerosis.

PurposeIntranasally delivered ST266, the biological, proteinaceous secretome of amnion-derived multipotent progenitor cells, reduces retinal ganglion cell (RGC) loss, optic nerve inflammation, and demyelination in experimental optic neuritis. This unique therapy and novel administration route delivers numerous cytokines and growth factors to the eye and optic nerve, suggesting a potential to also treat other optic neuropathies. Thus, ST266-mediated neuroprotection was examined following traumatic optic nerve injury.MethodsOptic nerve crush injury was surgically induced in C57BL/6J mice. Mice were treated daily with intranasal PBS or ST266. RGC function was assessed by optokinetic responses (OKRs), RGCs were counted, and optic nerve sections were stained with luxol fast blue and anti-neurofilament antibodies to assess myelin and RGC axon damage.ResultsIntranasal ST266 administered daily for 5 days, beginning at the time that a 1-second optic nerve crush was performed, significantly attenuated OKR decreases. Furthermore, ST266 treatment reduced damage to RGC axons and myelin within optic nerves, and blocked RGC loss. Following a 4-second optic nerve crush, intranasal ST266 increased RGC survival and showed a trend toward reduced RGC axon and myelin damage. Ten days following optic nerve crush, ST266 prevented myelin damage, while also inducing a trend toward increased RGC survival and visual function.ConclusionsST266 significantly attenuates traumatic optic neuropathy. Neuroprotective effects of this unique combination of biologic molecules observed here and previously in optic neuritis suggest potential broad application for preventing neuronal damage in multiple optic nerve disorders. Furthermore, results support intranasal delivery as a novel, noninvasive therapeutic modality for eyes and optic nerves.

Introduction: Prior studies showed that intranasally administered ST266, a novel biological secretome of Amnion-derived Multipotent Progenitor cells containing multiple growth factors and anti-inflammatory cytokines, attenuated visual dysfunction and prevented retinal ganglion cell (RGC) loss in experimental optic neuritis. Long-term effects and dose escalation studies examined here have not been reported previously. Methods: Optic neuritis was induced in the multiple sclerosis model experimental autoimmune encephalomyelitis (EAE). EAE and control mice were treated once or twice daily with intranasal placebo/vehicle or ST266 beginning after onset of optic neuritis for either 15 days or continuously until sacrifice. Visual function was assessed by optokinetic responses (OKR). RGC survival and optic nerve inflammation and demyelination were measured. Results: Both once and twice daily continuous intranasal ST266 treatment from disease onset to 56 days post-EAE induction significantly increased OKR scores, decreased RGC loss, and reduced optic nerve inflammation and demyelination compared with placebo (saline, non-specific protein

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ST266 is the biological secretome of cultured Amnion-derived Multipotent Progenitor cells containing multiple growth factors and cytokines. While intranasally-administered ST266 improves the phenotype in experimental optic neuritis, specific ST266 components mediating these effects are not known. We compared the effects of ST266 with and without removal of large molecular weight proteins both in vitro and in the multiple sclerosis model experimental autoimmune encephalomyelitis (EAE) in C57BL/6J mice. Mice were treated daily with intranasal vehicle, ST266 or lower molecular weight fraction of ST266. Retinal ganglion cells were counted in isolated retinas, and optic nerves were assessed for inflammation and demyelination. ST266 treatment significantly improved retinal ganglion cell survival and reduced optic nerve demyelination in EAE mice. The lower molecular weight ST266 fraction significantly improved optic nerve demyelination, but only showed a trend towards improved retinal ganglion cell survival. ST266 fractions below 50kDa increased Schwann cell proliferation in vitro, but were less effective than non-fractionated ST266. Demyelination attenuation was partially associated with the lower molecular weight ST266 fraction, but removal of higher molecular weight biomolecules from ST266 diminishes its neuroprotective effects, suggesting at least some high molecular weight proteins play a role in ST266-mediated neuroprotection.