Mutant superoxide dismutase 1-catalyzed hydrogen therapy for amyotrophic lateral sclerosis achieved by intercepting oxidative stress-neuroinflammation crosstalk.

Abstract

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron degeneration in the brain and spinal cord, with mutant superoxide dismutase 1 (SOD1) induced oxidative stress and neuroinflammation as key pathogenic drivers. Here, we uncover that mutant SOD1 is both a Fenton-like agent able for catalytical generation of ·OH and a hydrogenation catalyst for H₂ scavenging reactive oxygen species. To enhance the bioavailability of H₂, we develop an orally administered Mg₂Si nanosheets based feed for sustained release of high-amount H₂. On an ALS model of hSOD1^G93A transgenic mice, Mg₂Si feed remarkably delays ALS progression, improves the motor performance of ALS mice, and extends their lifespan. Histopathologically, oral Mg₂Si treatment ameliorates motor neuron degeneration, misfolded SOD1 aggregation and reactive gliosis in spinal cord, while protecting neuromuscular junctions and ameliorating muscle atrophy during disease progression. Transcriptomic analysis demonstrates the H₂-mediated down-regulation of both oxidative stress and neuroinflammatory pathways in response to the suppression of NLRP3 inflammasome activation. The proposed strategy of catalyzed hydrogen therapy offers an inspiration for metalloproteases-related neurodegenerative diseases treatment. STATEMENT OF SIGNIFICANCE: Amyotrophic lateral sclerosis (ALS) is an incurable and devastating neurodegenerative disease lacking effective clinical interventions. Although hydrogen gas (H₂) exhibits promising neuroprotective potential, conventional H₂ therapy is severely limited by unstable and transient H₂ release, failing to sustain long-term treatment requirements for chronic ALS pathogenesis. To overcome this bottleneck, we engineer oral administrable Mg₂Si nanosheets that enable sustained H₂ release via gastrointestinal retention, achieving stable long-term hydrogen supplementation in vivo. Mechanistically, Mg₂Si-derived H₂ efficiently eliminates excess free radicals triggered by toxic mutant SOD1, and further disrupts the pathological crosstalk between oxidative stress and neuroinflammation in ALS. In transgenic ALS mice, dietary Mg₂Si intervention markedly ameliorates motor dysfunction and effectively delays disease progression. Collectively, this study firstly applies Mg₂Si nanomaterial-based sustained hydrogen therapy for ALS treatment, establishes a novel gastrointestinal hydrogen delivery strategy, and provides an innovative and clinically translatable paradigm for the design of hydrogen delivery systems against neurodegenerative disorders.