Broad spectrum proteomics analysis of the inferior Colliculus following acute hydrogen sulfide exposure

Abstract

Acute exposure to high concentrations of H ₂ S causes severe brain injury and long-term neurological disorders. The mechanisms of H ₂ S-induced neurodegeneration are not known. To better understand the cellular and molecular mechanisms of H ₂ S-induced neurodegeneration we used a broad-spectrum proteomic analysis approach to search for key molecules in H ₂ S-induced neurotoxicity. Mice were subjected to acute whole body exposure of up to 750 ppm of H ₂ S. The H ₂ S-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 H ₂ S 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 H ₂ S-dependent proteomics changes. Taken together, acute exposure to H ₂ S 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 H ₂ S-induced neurotoxicity.