Effect of intranasal administration of NeuroEPO in the histological structure of the olfactory mucosa of Wistar rats / Efecto de la administración intranasal de NeuroEPO en la estructura histológica de la mucosa olfatoria de ratas Wistar

Introduction: Strokes and neurodegenerative diseases are major global health problems, not only because they cause high mortality and disability, but due to the lack of effective therapies. NeuroEPO, a variant of recombinant human erythropoietin (rHu-EPO) with a low sialic acid content, has shown encouraging results as a potential neuroprotective agent when administered intranasally. Objective: To determine the effect of intranasal administration of NeuroEPO on the histological structure of the olfactory mucosa of Wistar rats. Materials and Methods: An experimental, prospective, and longitudinal study was conducted on Wistar rats. Ten healthy animals were randomly distributed into two groups of five each. The control group received a vehicle (0.3 μl/g/day) and the treated group received NeuroEPO (300 μg/kg/day). Both treatments were administered intranasally for 28 days. The histological characteristics of the olfactory mucosa were evaluated. The medians between the study groups were compared using the Mann-Whitney U test. Results: There were no alterations in the histological characteristics of the olfactory epithelium. However, slight hypertrophy and hyperplasia of the Bowman's glands were observed at the level of the lamina propria in the group treated with NeuroEPO. Conclusions: The administration of the nasal formulation of NeuroEPO did not induce histological alterations of the olfactory mucosa of Wistar rats under the experimental conditions of this research.

Introducción: Los accidentes cerebrovasculares y las enfermedades neurodegenerativas constituyen un importante problema de salud mundial. No solo porque causan una alta mortalidad y discapacidad, sino por la falta de terapias eficaces para tratarlos. La NeuroEPO, una variante de la eritropoyetina humana recombinante (rHu-EPO) con bajo contenido en ácido siálico, ha mostrado resultados alentadores como potencial agente neuroprotector al ser administrada por vía intranasal. Objetivo: Determinar el efecto de la administración intranasal de NeuroEPO en la estructura histológica de la mucosa olfatoria de ratas Wistar. Materiales y Métodos: Se realizó un estudio experimental, prospectivo y de corte longitudinal en ratas Wistar. Se utilizaron diez animales sanos distribuidos aleatoriamente en dos grupos de cinco cada uno. El grupo control recibió vehículo (0,3 μl/g/día) y el grupo tratado recibió NeuroEPO (300 μg/kg/día). Ambos tratamientos fueron administrados por vía intranasal durante 28 días. Fueron evaluadas las características histológicas de la mucosa olfatoria. Las medianas de los grupos del estudio fueron comparadas mediante la prueba U de Mann-Whitney. Resultados: No se evidenciaron alteraciones en las características histológicas del epitelio olfatorio. Sin embargo, a nivel de la lámina propia en el grupo tratado con NeuroEPO, se observó una ligera hipertrofia e hiperplasia de las glándulas de Bowman. Conclusiones: La administración de la formulación nasal de NeuroEPO no indujo alteraciones histopatológicas de la mucosa olfatoria de ratas Wistar en las condiciones experimentales de esta investigación.

Intranasal administration of NeuroEPO does not affect the structure of respiratory mucosa in Wistar rats / La administración de NeuroEPO intranasal no afecta la estructura de la mucosa respiratoria en ratas Wistar

Introduction: Diseases associated with the Central Nervous System represent a group of conditions with important social and economic repercussions. New treatment strategies with NeuroEPO offer new opportunities to prevent the onset and progression of these disorders. NeuroEPO administered intranasally can reach the Central Nervous System through various mechanisms involving the olfactory and trigeminal nerves, respiratory and olfactory mucosa, nasal vasculature, cerebrospinal fluid, and the lymphatic system. Objective: To determine the effect of intranasal administration of NeuroEPO on the histologic structure of the respiratory mucosa and its associated lymphatic tissue in Wistar rats. Material and Methods: An experimental, descriptive, longitudinal, prospective study was conducted, using the Wistar rat as a biological model. Ten healthy animals were randomly distributed in two groups of five animals each. One of the groups received intranasal NeuroEPO for 28 days at doses of 300 μg/kg. The other group was given a vehicle at a rate of 0,3μl/g. The histological characteristics of the respiratory mucosa were studied. The Mann-Whitney test was used to compare the means. Results: No alterations in the histological characteristics of the respiratory mucosa and the lymphatic tissue associated with the nasal mucosa were observed in Wistar rats after the administration of NeuroEPO. Conclusion: Intranasal administration of NeuroEPO does not cause pathological changes in the histological structure of the respiratory mucosa or the lymphatic tissue associated with the nasal mucosa of Wistar rats in our experimental conditions.

Introducción: Las enfermedades asociadas al Sistema Nervioso Central representan un grupo de padecimientos con importante repercusión social y económica. Las nuevas estrategias de tratamiento con NeuroEPO ofrecen nuevas oportunidades para prevenir la aparición y la progresión de estos desórdenes. La NeuroEPO administrada por vía intranasal puede alcanzar al Sistema Nervioso Central a través de varios mecanismos que involucran los nervios olfatorios y trigéminos, mucosa respiratoria y olfatoria, vasculatura nasal, fluido cerebroespinal y el sistema linfático. Objetivo: Determinar el efecto de la administración intranasal de NeuroEPO sobre la estructura histológica de la mucosa respiratoria y de su tejido linfático asociado en ratas Wistar. Material y métodos: Se realizó un estudio experimental, descriptivo, longitudinal, prospectivo, utilizando la rata Wistar como modelo biológico. Se utilizaron diez animales sanos distribuidos aleatoriamente en dos grupos de cinco cada uno. Uno de los grupos recibió NeuroEPO intranasal durante 28 días a dosis de 300 µg/ kg. Al otro grupo se le administró vehículo a una razón de 0,3µl /g. Se estudiaron las características histológicas de la mucosa respiratoria. Las medianas de los grupos fueron comparadas mediante la prueba U de Mann-Whitney. Resultados: No se observaron alteraciones en las características histológicas de la mucosa respiratoria, ni del tejido linfático asociado a la mucosa nasal en ratas Wistar, tras la administración de la NeuroEPO. Conclusión: La administración intranasal de NeuroEPO no provoca cambios patológicos sobre la estructura histológica de la mucosa respiratoria ni del tejido linfático asociado a la mucosa nasal de ratas Wistar en nuestras condiciones experimentales.

An Intranasal Formulation of Erythropoietin (Neuro-EPO) Prevents Memory Deficits and Amyloid Toxicity in the APPSwe Transgenic Mouse Model of Alzheimer's Disease.

Erythropoietin (EPO) is a cytokine known to have effective cytoprotective action in the brain, particularly in ischemic, traumatic, inflammatory, and neurodegenerative conditions. We previously reported the neuroprotective effect of a low sialic form of EPO, Neuro-EPO, applied intranasally in rodent models of stroke or cerebellar ataxia and in a non-transgenic mouse model of Alzheimer's disease (AD). Here we analyzed the protective effect of Neuro-EPO in APPSwe mice, a reference transgenic mouse model of AD. Mice were administered 3 times a day, 3 days in the week with Neuro-EPO (125, 250 µg/kg) intranasally, between 12 and 14 months of age. Motor responses, general activity, and memory responses were analyzed during and after treatment. The deficits in spontaneous alternation, place learning in the water-maze, and novel object recognition observed in APPSwe mice were alleviated by the low dose of Neuro-EPO. Oxidative stress, neuroinflammation, trophic factor levels, and a synaptic marker were analyzed in the hippocampus or cortex of the animals. The increases in lipid peroxidation or in GFAP and Iba-1 contents in APPSwe mice were significantly reduced after Neuro-EPO. Activation of intrinsic and extrinsic apoptotic pathways was analyzed. The increases in Bax/Bcl-2 ratio, TNFα, or Fas ligand levels observed in APPSwe mice were reduced by Neuro-EPO. Finally, immunohistochemical and ELISA analyses of Aß1-42 levels in the APPSwe mouse cortex and hippocampus showed a marked reduction in Aß deposits and in soluble and insoluble Aß1-42 forms. This study therefore confirmed the neuroprotective activity of EPO, particularly for an intranasally deliverable formulation, devoid of erythropoietic side effects, in a transgenic mouse model of AD. Neuro-EPO alleviated memory alterations, oxidative stress, neuroinflammation, apoptosis induction, and amyloid load in 14-month-old APPSwe mice.

Intranasal formulation of erythropoietin (EPO) showed potent protective activity against amyloid toxicity in the Aß25₋35 non-transgenic mouse model of Alzheimer's disease.

Erythropoietin (EPO) promotes neurogenesis and neuroprotection. We here compared the protection induced by two EPO formulations in a rodent model of Alzheimer's disease (AD): rHu-EPO and a low sialic form, Neuro-EPO. We used the intracerebroventricular administration of aggregated Aß25₋35 peptide, a non-transgenic AD model. rHu-EPO was tested at 125-500 µg/kg intraperitoneally and Neuro-EPO at 62-250 µg/kg intranasally (IN). Behavioural procedures included spontaneous alternation, passive avoidance, water-maze and object recognition, to address spatial and non-spatial, short- and long-term memories. Biochemical markers of Aß25₋35 toxicity in the mouse hippocampus were examined and cell loss in the CA1 layer was determined. rHu-EPO and Neuro-EPO led to a significant prevention of Aß25₋35-induced learning deficits. Both EPO formulations prevented the induction of lipid peroxidation in the hippocampus, showing an antioxidant activity. rHu-EPO (250 µg/kg) or Neuro-EPO (125 µg/kg) prevented the Aß25₋35-induced increase in Bax level, TNFα and IL-1ß production and decrease in Akt activation. A significant prevention of the Aß25₋35-induced cell loss in CA1 was also observed. EPO is neuroprotective in the Aß25₋35 AD model, confirming its potential as an endogenous neuroprotection system that could be boosted for therapeutic efficacy. We here identified a new IN formulation of EPO showing high neuroprotective activity. Considering its efficacy, ease and safety, IN Neuro-EPO is a new promising therapeutic agent in AD.

Treatment with nasal neuro-EPO improves the neurological, cognitive, and histological state in a gerbil model of focal ischemia.

Vascular illness of the brain constitutes the third cause of death and the first cause of disability in Cuba and many other countries. Presently, no medication has been registered as a neuroprotector. Neuroprotection with intranasal Neuro-EPO (EPO, erythropoietin) has emerged as a multifunctional therapy that plays a significant role in neural survival and functional recovery in an animal model of stroke. On the other hand, there is limited access to the brain through the blood brain barrier (BBB) for intravenously applied EPO, and the high EPO dosages needed to obtain a protective effect increase the danger of elevated hematocrit levels and practically exclude chronic or subchronic treatment with EPO. A promising approach has been recently developed with a nonerythropoietic variant of EPO, Neuro-EPO, with low sialic acid content, a very short plasma half-life, and without erythropoietic activity, probably similar to endogenous brain EPO. The objective of this work was to determine the neuroprotective effect of intranasal Neuro-EPO in comparison with the human recombinant EPO injected intraperitoneally in the acute phase of cerebral ischemia, employing the common carotid artery occlusion model in gerbils. Neuro-EPO has demonstrated a better neuroprotective effect, evidenced through increased viability, improvements of the neurological state and cognitive functions, as well as protection of the CA3 region of the hippocampus, temporal cortex, and the thalamus. In conclusion, the intranasal application of Neuro-EPO has a better neuroprotective effect than intraperitoneal EPO, evidenced by the significant improvement of neurological, cognitive, and histological status in the animal model of stroke employed.