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Published on: July 22, 2014
Mitochondrially Transcribed DsRNA Mediates Manganese-Induced Neuroinflammation.
Hadassah Mendez-Vazquez1, Avanti Gokhale1, Maureen M Sampson2
1Department of Cell Biology, Emory University, Atlanta, Georgia 30322.
Summary
Excess manganese causes neurotoxicity by disrupting mitochondrial RNA processing, leading to double-stranded RNA accumulation and inflammation. This discovery reveals a new pathway in manganese-induced neurodegeneration.
Area of Science:
- Neuroscience
- Toxicology
- Molecular Biology
Background:
- Manganese is essential but toxic in excess, causing neurodegeneration.
- Mechanisms of manganese neurotoxicity are not fully understood.
- Neuropathology shows astrogliosis, neuronal loss, and neuroinflammation.
Purpose of the Study:
- Investigate a novel manganese-dependent mechanism linking mitochondrial dysfunction to neuroinflammation.
- Identify the role of mitochondrial RNA processing in manganese toxicity.
Main Methods:
- Utilized human cerebral organoids and Slc30a10 mutant mice models.
- Analyzed mitochondrial transcriptome processing, dsRNA accumulation, and inflammatory responses.
- Assessed MDA5 activation and type I interferon signaling.
Main Results:
- Manganese disrupts mitochondrial RNA processing, causing double-stranded RNA (dsRNA) accumulation.
- Cytoplasmic dsRNA activates MDA5, triggering type I interferon and inflammatory cytokine production.
- This pathway was observed in human cerebral organoids and mouse models of hypermanganesemia.
Conclusions:
- Mitochondrial dsRNA accumulation is a key mediator of manganese-induced neuroinflammation.
- This pathway offers insights into manganism pathogenesis and potential therapeutic targets.
- The manganese-dsRNA axis may be implicated in other neurodegenerative diseases.
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