Mucosal organs exhibit distinct response signatures to hydrogen sulphide in Atlantic salmon ( Salmo salar )
Hydrogen sulphide (H 2 S) is considered an immunotoxicant, and its presence in the water can influence the mucosal barrier functions of fish. However, there is a significant knowledge gap on how fish mucosa responds to low environmental H 2 S levels. The present study investigated the consequences o...
| Published in: | Ecotoxicology and Environmental Safety |
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| Main Authors: | , , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
2024
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| Subjects: | |
| Online Access: | https://orbit.dtu.dk/en/publications/1b1cc927-03db-4ad1-9e76-505120c7860b https://doi.org/10.1016/j.ecoenv.2024.116617 https://backend.orbit.dtu.dk/ws/files/364985579/1-s2.0-S0147651324006936-main.pdf |
| Summary: | Hydrogen sulphide (H 2 S) is considered an immunotoxicant, and its presence in the water can influence the mucosal barrier functions of fish. However, there is a significant knowledge gap on how fish mucosa responds to low environmental H 2 S levels. The present study investigated the consequences of prolonged exposure to sub-lethal levels of H2S on the mucosal defences of Atlantic salmon (Salmo salar). Fish were continuously exposed to two levels of H2S (low: 0.05 µM; and high: 0.12 µM) for 12 days. Unexposed fish served as control. Molecular and histological profiling focused on the changes in the skin, gills and olfactory rosette. In addition, metabolomics and proteomics were performed on the skin and gill mucus. The gene expression profile indicated that the gills and olfactory rosette were more sensitive to H2S than the skin. The olfactory rosette showed a dose-dependent response, but not the gills. Genes related to stress responses were triggered at mucosal sites by H2S. Moreover, H2S elicited strong inflammatory responses, particularly in the gills. All mucosal organs demonstrated the key molecular repertoire for sulphide detoxification, but their temporal and spatial expression was not substantially affected by sub-lethal H 2 S levels. Mucosal barrier integrity was not considerably affected by H 2 S. Mucus metabolomes of the skin and gills were unaffected, but a matrix-dependent response was identified. Comparing the high-concentration group's skin and gills mucus metabolomes identified altered amino acid biosynthesis and metabolism pathways. The skin and gill mucus exhibited distinct proteomic profiles. Enrichment analysis revealed that proteins related to immunity and metabolism were affected in both mucus matrices. The present study expands our knowledge of the defence mechanisms against H2S at mucosal sites in Atlantic salmon. The findings offer insights into the health and welfare consequences of sub-lethal H 2 S, which can be incorporated into the risk assessment protocols in salmon land-based ... |
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