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Proteomic profiling of cellular steatosis with concomitant oxidative stress in vitro.

Lockman KA, Htun V, Sinha R, Treskes P, Nelson LJ, Martin SF, Rogers SM, Le Bihan T, Hayes PC, Plevris JN - Lipids Health Dis (2016)

Bottom Line: Lipid binding annotations were also enriched as well as proteins involved in cholesterol synthesis, uptake and efflux.Increased expression of aldo-keto reductase family 1, member C1 and C3 suggests enhanced sterol metabolism and increased ROS-mediated lipid peroxidation.The surge of energy substrates diverts free fatty acid metabolism towards pathways that can mitigate lipotoxicity.

View Article: PubMed Central - PubMed

Affiliation: Hepatology Laboratory, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, Scotland, UK.

ABSTRACT

Background: Nutrient excess underpins the development of nonalcoholic fatty liver disease (NAFLD). The ensuing metabolic derangement is characterised by increased cellular respiration, oxidative stress and mitochondrial impairment. We have previously recapitulated these events in an in vitro cellular steatosis model. Here, we examined the distinct patterns of protein expression involved using a proteomics approach.

Methods: Human hepatoblastoma C3A cells were treated with a combination of energy substrates; lactate (L), pyruvate (P), octanoate (O) and ammonia (N). Proteins extracts were trypsinized and analyzed on a capillary HPLC OrbitrapXL mass spectrometer. Proteins were quantified using a label-free intensity based approach. Functional enrichment analysis was performed using ToppCluster via Gene Ontology (GO) database.

Results: Of the 1327 proteins identified, 104 were differentially expressed between LPON and untreated cells (defined as: ≥2 peptides; fold change ≥1.5; p-value <0.05). Seventy of these were upregulated with LPON. Functional enrichment analysis revealed enhanced protein biosynthesis accompanied by downregulation of histones H2A type 1-A, H1.2, H1.5 and H1.0I in LPON cells. Lipid binding annotations were also enriched as well as proteins involved in cholesterol synthesis, uptake and efflux. Increased expression of aldo-keto reductase family 1, member C1 and C3 suggests enhanced sterol metabolism and increased ROS-mediated lipid peroxidation.

Conclusions: The surge of energy substrates diverts free fatty acid metabolism towards pathways that can mitigate lipotoxicity. The histones depletion may represent an adaptation to increased protein synthesis. However, this can also expose DNA to oxidative stress thus should be explored further in the context of NAFLD progression.

No MeSH data available.


Related in: MedlinePlus

Enrichment analysis for LPON treated cells using Blast2GO. a Overrepresented GO: Molecular Function terms in LPON treated cells. b Enrichment bar chart of significant GO: Molecular Function term demonstrating the percentage of sequences annotated with LPON compared with the reference set based on the Fishers Exact Test results
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Fig1: Enrichment analysis for LPON treated cells using Blast2GO. a Overrepresented GO: Molecular Function terms in LPON treated cells. b Enrichment bar chart of significant GO: Molecular Function term demonstrating the percentage of sequences annotated with LPON compared with the reference set based on the Fishers Exact Test results

Mentions: Enrichment analysis by Blast2GO (Fig. 1) found only “lipid binding”, a broader GO term, to be enriched. Proteins found to be enriched in this set, that were not found by ToppCluster, included apolipoprotein A-I preproprotein (APOA1; fold change: 4.08), vigilin (HDLBP; fold change: 2.72), and apolipoprotein E precursor (APOE; fold change: 2.21).Fig. 1


Proteomic profiling of cellular steatosis with concomitant oxidative stress in vitro.

Lockman KA, Htun V, Sinha R, Treskes P, Nelson LJ, Martin SF, Rogers SM, Le Bihan T, Hayes PC, Plevris JN - Lipids Health Dis (2016)

Enrichment analysis for LPON treated cells using Blast2GO. a Overrepresented GO: Molecular Function terms in LPON treated cells. b Enrichment bar chart of significant GO: Molecular Function term demonstrating the percentage of sequences annotated with LPON compared with the reference set based on the Fishers Exact Test results
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4930558&req=5

Fig1: Enrichment analysis for LPON treated cells using Blast2GO. a Overrepresented GO: Molecular Function terms in LPON treated cells. b Enrichment bar chart of significant GO: Molecular Function term demonstrating the percentage of sequences annotated with LPON compared with the reference set based on the Fishers Exact Test results
Mentions: Enrichment analysis by Blast2GO (Fig. 1) found only “lipid binding”, a broader GO term, to be enriched. Proteins found to be enriched in this set, that were not found by ToppCluster, included apolipoprotein A-I preproprotein (APOA1; fold change: 4.08), vigilin (HDLBP; fold change: 2.72), and apolipoprotein E precursor (APOE; fold change: 2.21).Fig. 1

Bottom Line: Lipid binding annotations were also enriched as well as proteins involved in cholesterol synthesis, uptake and efflux.Increased expression of aldo-keto reductase family 1, member C1 and C3 suggests enhanced sterol metabolism and increased ROS-mediated lipid peroxidation.The surge of energy substrates diverts free fatty acid metabolism towards pathways that can mitigate lipotoxicity.

View Article: PubMed Central - PubMed

Affiliation: Hepatology Laboratory, University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, Scotland, UK.

ABSTRACT

Background: Nutrient excess underpins the development of nonalcoholic fatty liver disease (NAFLD). The ensuing metabolic derangement is characterised by increased cellular respiration, oxidative stress and mitochondrial impairment. We have previously recapitulated these events in an in vitro cellular steatosis model. Here, we examined the distinct patterns of protein expression involved using a proteomics approach.

Methods: Human hepatoblastoma C3A cells were treated with a combination of energy substrates; lactate (L), pyruvate (P), octanoate (O) and ammonia (N). Proteins extracts were trypsinized and analyzed on a capillary HPLC OrbitrapXL mass spectrometer. Proteins were quantified using a label-free intensity based approach. Functional enrichment analysis was performed using ToppCluster via Gene Ontology (GO) database.

Results: Of the 1327 proteins identified, 104 were differentially expressed between LPON and untreated cells (defined as: ≥2 peptides; fold change ≥1.5; p-value <0.05). Seventy of these were upregulated with LPON. Functional enrichment analysis revealed enhanced protein biosynthesis accompanied by downregulation of histones H2A type 1-A, H1.2, H1.5 and H1.0I in LPON cells. Lipid binding annotations were also enriched as well as proteins involved in cholesterol synthesis, uptake and efflux. Increased expression of aldo-keto reductase family 1, member C1 and C3 suggests enhanced sterol metabolism and increased ROS-mediated lipid peroxidation.

Conclusions: The surge of energy substrates diverts free fatty acid metabolism towards pathways that can mitigate lipotoxicity. The histones depletion may represent an adaptation to increased protein synthesis. However, this can also expose DNA to oxidative stress thus should be explored further in the context of NAFLD progression.

No MeSH data available.


Related in: MedlinePlus