Use of Interferon beta and 4-hydroxy-tempo in the treatment of Amyotrophic Lateral Sclerosis in SOD1G93A mice

• Grant number: 20/15892-8
• Support type: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): March 01, 2021
• Effective date (End): January 31, 2024
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal researcher: Alexandre Leite Rodrigues de Oliveira
• Grantee: Ana Laura Midori Rossi Tomiyama
• Home Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 18/05006-0 - Sensorimotor recovery following spinal root axotomy: use of different experimental approaches, AP.TEM

Abstract

Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that progressively affects the upper and lower motor neurons of the spinal cord. Its symptoms are mainly muscle weakness and atrophy, which progress to death, usually due to respiratory arrest. ALS can be classified as: family member (10%), which has a hereditary and sporadic origin, which represents the majority of cases (90%), and remains with unknown etiology. In both types, clinical signs are consequences of mutations that cause excitotoxicity in the neuronal environment. Also, a drop in the expression of MHC class I (MHC-I) in the nervous system has been observed. This molecule has a classic function in the immune system, but it also plays important role in the nervous system, especially after injuries. Astrocytes are supposed to inhibit the expression of MHC-I by neurons, preventing them from exercising any neuroprotective role. With this in mind, the objective of the present study was to verify the influence of treatment with Interferon beta (IFN beta), a pro-inflammatory cytokine that induces increased expression of MHC-I, on neuronal survival of motor neurons and glial reactivity in transgenic mice SOD1G93A. For that, daily doses (250, 1000, and 10,000 IU) were administered, from 70 to 90 days of life (pre-symptomatic phase). Thus, spinal cords were collected for comparative analysis by immunofluorescence (reactive gliosis) and Nissl staining (neuronal survival). Besides, the experimental groups underwent motor evaluation on the Rotarod device, weight monitoring, and neurological score. The results obtained show that the treatment with IFN beta, in the lowest dose (250UI), resulted in a significant increase in neuronal survival. Astrogliosis decreased in the treated groups compared to the vehicle group, being inversely proportional to the tested dose. In contrast, microglial reactivity increased significantly in the group that received a dose of 1000 IU, when compared to the vehicle. The Rotarod motor tests, score, and body weight showed no significant differences. From these results, we decided to add the treatment with the antioxidant molecule Tempol (50mg/Kg), a mimetic of the enzyme superoxide dismutase 1 (SOD1), and also the combination of Tempol with IFN beta (250UI), both in the pre-symptomatic, as well as in the initial symptomatic period (100 days), in addition to adding the flow cytometry technique, to broaden the understanding of the effectiveness of treatments in glial reactivity. (AU)