The transcriptomic responses of Atlantic salmon (Salmo salar) to high temperature stress alone, and in combination with moderate hypoxia

Abstract Background Increases in ocean temperatures and in the frequency and severity of hypoxic events are expected with climate change, and may become a challenge for cultured Atlantic salmon and negatively affect their growth, immunology and welfare. Thus, we examined how an incremental temperature increase alone (Warm & Normoxic-WN: 12 → 20 °C; 1 °C week− 1), and in combination with moderate hypoxia (Warm & Hypoxic-WH: ~ 70% air saturation), impacted the salmon’s hepatic transcriptome expr\ession compared to control fish (CT: 12 °C, normoxic) using 44 K microarrays and qPCR. Results Overall, we identified 2894 differentially expressed probes (DEPs, FDR < 5%), that included 1111 shared DEPs, while 789 and 994 DEPs were specific to WN and WH fish, respectively. Pathway analysis indicated that the cellular mechanisms affected by the two experimental conditions were quite similar, with up-regulated genes functionally associated with the heat shock response, ER-stress, apoptosis and immune defence, while genes connected with general metabolic processes, proteolysis and oxidation-reduction were largely suppressed. The qPCR assessment of 41 microarray-identified genes validated that the heat shock response (hsp90aa1, serpinh1), apoptosis (casp8, jund, jak2) and immune responses (apod, c1ql2, epx) were up-regulated in WN and WH fish, while oxidative stress and hypoxia sensitive genes were down-regulated (cirbp, cyp1a1, egln2, gstt1, hif1α, prdx6, rraga, ucp2). However, the additional challenge of hypoxia resulted in more pronounced effects on heat shock and immune-related processes, including a stronger influence on the expression of 14 immune-related genes. Finally, robust correlations between the transcription of 19 genes and several phenotypic traits in WH fish suggest that changes in gene expression were related to impaired physiological and growth performance. Conclusion Increasing temperature to 20 °C alone, and in combination with hypoxia, resulted in the differential expression of genes involved in similar pathways in Atlantic salmon. However, the expression responses of heat shock and immune-relevant genes in fish exposed to 20 °C and hypoxia were more affected, and strongly related to phenotypic characteristics (e.g., growth). This study provides valuable information on how these two environmental challenges affect the expression of stress-, metabolic- and immune-related genes and pathways, and identifies potential biomarker genes for improving our understanding of fish health and welfare.

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The Transcriptomic Responses of Atlantic Salmon (Salmo salar) to High Temperature Stress Alone, and in Combination with Moderate Hypoxia

10.21203/rs.3.rs-38228/v1 ◽

2020 ◽

Author(s):

Anne Beemelmanns ◽

Fábio Sabbadin Zanuzzo ◽

Xi Xue ◽

Rebeccah M. Sandrelli ◽

Matthew L. Rise ◽

...

Keyword(s):

Heat Shock ◽

Atlantic Salmon ◽

Immune Responses ◽

Heat Shock Response ◽

Control Fish ◽

Phenotypic Traits ◽

Moderate Hypoxia ◽

Potential Biomarker ◽

Shock Response ◽

Immune Related Genes

Abstract Background: Increases in seawater temperatures and in the frequency and severity of hypoxic events are expected with climate change, and may become a challenge for cultured Atlantic salmon and negatively affect their growth, immunology and welfare. Thus, we examined how an incremental temperature increase alone (Warm & Normoxic-WN: 12→20°C; 1°C week-1), and in combination with moderate hypoxia (Warm & Hypoxic-WH: ~70% air saturation), impacted salmon’s hepatic transcriptome expression compared to control fish (CT: 12°C, normoxic) using 44K microarrays and qPCR. Results: Overall, we identified 2,894 differentially expressed probes (DEPs, FDR < 5%), that included 1,111 shared DEPs, while 789 and 994 DEPs were specific to WN and WH fish, respectively. Pathway analysis suggested that the cellular mechanisms affected by the two experimental conditions were quite similar, with up-regulated genes functionally associated with heat shock response, ER-stress, apoptosis and immune defence, while genes connected with general metabolic processes, proteolysis and oxidation-reduction were largely suppressed. The qPCR assessment of 41 microarray-identified genes validated that the heat shock response (hsp90aa1, serpinh1), apoptosis (casp8, jund, jak2) and immune responses (apod, c1ql2, epx) were up-regulated in WN and WH fish, while oxidative stress and hypoxia sensitive genes were down-regulated (cirbp, cyp1a1, egln2, gstt1, hif1α, prdx6, rraga, ucp2). However, the additional challenge of hypoxia resulted in more pronounced effects on heat shock and immune-related processes, including a stronger influence on the expression of 14 immune-related genes. Finally, robust correlations between the transcription of 19 genes and several phenotypic traits in WH fish suggest that changes in gene expression were related to an impaired physiological and growth performance. Conclusion: Increasing temperature to 20°C alone, and in combination with hypoxia, resulted in the up- and down-regulation of genes involved in similar important pathways in Atlantic salmon. However, the heat shock and immune responses of fish exposed to 20°C and hypoxia were more affected, and their transcriptional dysregulation was related to reduced performance. This study provides valuable information on how these two environmental challenges affect the expression of stress-, metabolic- and immune-related genes and pathways and identifies potential biomarker genes for improving our understanding of fish health and welfare.

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Activation of the heat shock response in a primary cellular model of motoneuron neurodegeneration-evidence for neuroprotective and neurotoxic effects

Cellular & Molecular Biology Letters ◽

10.2478/s11658-009-0002-8 ◽

2009 ◽

Vol 14 (2) ◽

Cited By ~ 38

Author(s):

Bernadett Kalmar ◽

Linda Greensmith

Keyword(s):

Cell Death ◽

Heat Shock ◽

Heat Shock Response ◽

Apoptotic Cell ◽

Experimental Conditions ◽

Pharmacological Agents ◽

Shock Response ◽

Induced Apoptosis ◽

Shock Proteins ◽

The Relationship

AbstractPharmacological up-regulation of heat shock proteins (hsps) rescues motoneurons from cell death in a mouse model of amyotrophic lateral sclerosis. However, the relationship between increased hsp expression and neuronal survival is not straightforward. Here we examined the effects of two pharmacological agents that induce the heat shock response via activation of HSF-1, on stressed primary motoneurons in culture. Although both arimoclomol and celastrol induced the expression of Hsp70, their effects on primary motoneurons in culture were significantly different. Whereas arimoclomol had survival-promoting effects, rescuing motoneurons from staurosporin and H2O2 induced apoptosis, celastrol not only failed to protect stressed motoneurons from apoptosis under same experimental conditions, but was neurotoxic and induced neuronal death. Immunostaining of celastrol-treated cultures for hsp70 and activated caspase-3 revealed that celastrol treatment activates both the heat shock response and the apoptotic cell death cascade. These results indicate that not all agents that activate the heat shock response will necessarily be neuroprotective.

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Accurate and Sensitive Quantitation of the Dynamic Heat Shock Proteome using Tandem Mass Tags

10.1101/696641 ◽

2019 ◽

Author(s):

Aaron J. Storey ◽

Rebecca E. Hardman ◽

Stephanie D. Byrum ◽

Samuel G. Mackintosh ◽

Rick D. Edmondson ◽

...

Keyword(s):

Heat Shock ◽

Heat Shock Response ◽

High Performance ◽

Global Changes ◽

Tandem Mass ◽

Protein Abundance ◽

Protein Activity ◽

Experimental Conditions ◽

Mass Spectrometers ◽

Shock Response

AbstractCells respond to environmental perturbations and insults through modulating protein abundance and function. However, the majority of studies have focused on changes in RNA abundance because quantitative transcriptomics has historically been more facile than quantitative proteomics. Modern Orbitrap mass spectrometers now provide sensitive and deep proteome coverage, allowing direct, global quantification of not only protein abundance, but also post-translational modifications (PTMs) that regulate protein activity. We implemented, and validated using the well-characterized heat shock response of budding yeast, a tandem mass tagging (TMT), triple-stage mass spectrometry (MS3) strategy to measure global changes in the proteome during the yeast heat shock response over nine timepoints. We report that basic pH, ultra-high performance liquid chromatography (UPLC) fractionation of tryptic peptides yields superfractions of minimal redundancy, a crucial requirement for deep coverage and quantification by subsequent LC-MS3. We quantified 2,275 proteins across 3 biological replicates, and found that differential expression peaked near 90 minutes following heat shock (with 868 differentially expressed proteins at 5% FDR). The sensitivity of the approach also allowed us to detect changes in the relative abundance of ubiquitination and phosphorylation PTMs over time. Remarkably, relative quantification of post-translationally modified peptides revealed striking evidence of regulation of the heat shock response by protein PTMs. These data demonstrate that the high precision of TMT-MS3 enables peptide-level quantification of samples, which can reveal important regulation of protein abundance and regulatory PTMs under various experimental conditions.

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