The Neuroprotective Role of TERT Influences the Expression of SOD1 in Motor Neurons and Mouse Brain: Implications for fALS

Abstract

Amyotrophic lateral sclerosis (ALS) disease is characterized by degeneration of motor neurons and elevation of brain oxidative stress. Previous studies demonstrated the neuroprotective effects of Telomerase reverse transcriptase (TERT) from oxidative stress. We showed that increasing TERT expression in the brain of the Tg hSOD1G93A mouse ALS model attenuated the disease pathology and increased the survival of motor neurons exposed to oxidative stress. How TERT increased the survival of motor neurons exposed to oxidative stress is not yet clear. Here we investigated the consequence of TERT depletion in motor neuron cells under normal and oxidative stress conditions and in mouse brains of TERT knockout mice, on the expression and activity of SOD1 and catalase enzymes. Depletion of mouse TERT caused mitochondrial dysfunction and impaired catalase and SOD1 activity. Compensation with hTERT restored the activity of SOD1. SOD1 expression increased in the brain of TERT KO and in ALS mice and decreased in the brain of WT mice treated with telomerase-increasing compounds. We suggest that the ability of TERT to protect neurons from oxidative stress affects the expression and activity of SOD1, in a TERT-dependent manner, and supports the notion of TERT as a therapeutic target for neurodegenerative diseases like ALS.