Beneficial effects of synthetic torpor in a fast-progressing mouse model of amyotrophic lateral sclerosis.

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by motor neuron loss, muscle atrophy, and progressive paralysis. Currently approved treatments provide only limited benefits. Due to the complex and multifactorial nature of ALS pathology, therapies targeting multiple pathways may prove more effective. Synthetic torpor, a state that mimics natural hibernation, has shown promise in promoting neuroprotection by modulating metabolism, reducing inflammation, and preserving both neurons and muscles. In this study, synthetic torpor was induced using 5'AMP combined with environmental cooling in the fast-progressing SOD1ALS mouse model on the 129SvHsd genetic background, known for its aggressive disease course, early metabolic dysfunction and unresponsiveness to treatments. Synthetic torpor was highly effective in preserving motor neurons. The treatment significantly delayed disease onset and extended survival, although mildly, without altering overall disease duration. In the spinal cord, synthetic torpor increased glucose transporters, reduced markers of oxidative stress, decreased glial activation and sustained upregulation of neuroprotective proteins, such as RBM3 and PPIA. This occurred despite an increased SOD1 aggregation in a later phase of the disease. Muscles display clear protective effects across disease progression with preservation of mass, reduced atrogin-1, lower PDK4 and oxidative stress markers, associated with improvements in markers of axonal integrity and muscle denervation. This study provides proof-of-concept that activating multiple protective molecular pathways, particularly those involved in glucose metabolism and protein folding, can mitigate the pathological processes in ALS, especially in rapidly progressing forms of the disease.