Abstract
Acute exposure to high concentrations of H2S causes severe brain injury and long-term neurological disorders. The mechanisms of H2S-induced neurodegeneration are not known. To better understand the cellular and molecular mechanisms of H2S-induced neurodegeneration we used a broad-spectrum proteomic analysis approach to search for key molecules in H2S-induced neurotoxicity. Mice were subjected to acute whole body exposure of up to750 ppm of H2S. The H2S-treated group showed behavioral motor deficits and developed severe lesions in the inferior colliculus (IC), part of the brainstem. The IC was microdissected for proteomic analysis. Tandem mass tags (TMT) liquid chromatography mass spectrometry (LC-MS/MS)-based quantitative proteomics was applied for protein identification and quantitation. LC-MS/MS was able to identify 598, 562, and 546 altered proteomic changes for day 1 (2 h post H2S exposure), day 2, and day 4 of H2S exposure, respectively. Mass spectrometry data were analyzed by Perseus 1.5.5.3 statistical analysis, and gene ontology heat map clustering. Quantitative real-time PCR was used to confirm some of the H2S-dependent proteomics changes. Taken together, acute exposure to H2S induced behavioral motor deficits along with progressive neurodegeneration including disruption of several biological processes in the IC such as cellular morphology, energy metabolism, and calcium signaling. The obtained broad-spectrum proteomics data may provide important clues to elucidate mechanisms of H2S-induced neurotoxicity.
Highlights
Mice exposed to H2S recapitulated H2S-induced neurotoxicity manifested in humans.
The IC in the mouse brain is the most sensitive to H2S-induced neurodegeneration.
Proteomic expressions of key proteins were validated at transcription level.
Several biological pathways were dysregulated by H2S exposure.