Limits...
Dietary phytochemicals modulate skin gene expression profiles and result in reduced lice counts after experimental infection in Atlantic salmon.

Jodaa Holm H, Wadsworth S, Bjelland AK, Krasnov A, Evensen Ø, Skugor S - Parasit Vectors (2016)

Bottom Line: Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth.In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Veterinary Medicine and Biosciences, Sea Lice Research Centre, Norwegian University of Life Sciences, PO Box 8146 Dep, 0033, Oslo, Norway.

ABSTRACT

Background: The use of phytochemicals is a promising solution in biological control against salmon louse (Lepeophtheirus salmonis). Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth. The aim of this study was to investigate if Atlantic salmon fed two different doses of glucosinolate-enriched feeds would be protected against lice infection. The effects of feeding high dose of glucosinolates before the infection, and of high and low doses five weeks into the infection were studied.

Methods: Skin was screened by 15 k oligonucleotide microarray and qPCR.

Results: A 25 % reduction (P < 0.05) in lice counts was obtained in the low dose group and a 17 % reduction in the high dose group compared to fish fed control feed. Microarray analysis revealed induction of over 50 interferon (IFN)-related genes prior to lice infection. Genes upregulated five weeks into the infection in glucosinolate-enriched dietary groups included Type 1 pro-inflammatory factors, antimicrobial and acute phase proteins, extracellular matrix remodeling proteases and iron homeostasis regulators. In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.

Conclusions: Atlantic salmon fed glucosinolates had a significantly lower number of sea lice at the end of the experimental challenge. Feeding glucosinolates coincided with increased expression of IFN-related genes, and higher expression profiles of Type 1 immune genes late into the infection. In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.

No MeSH data available.


Related in: MedlinePlus

Relative gene expression analysed by qPCR and microarray (MA) in skin behind dorsal fin from four groups of L. salmonis-infected Atlantic salmon fed different diets; not-infected high dose (NI-HD), infected control (I-C), infected low dose (I-LD) and infected high dose (I-HD). Relative gene expression is presented as ± fold difference. Bars represent mean fold ± SEM compared to not-infected control fish, NI-C. Number of fish in each qPCR group is 9 and 5 in MA analysis. One-way ANOVA followed by post-hoc Tukey’s multiple comparisons tests was performed between groups and control. Asterisks above bars denote significant differences between groups and control: ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05. Joined brackets show significant differences between experimental groups. The average correlation coefficient between MA and qPCR data was 0.8. a Relative gene expression of barrier-to-autointegration factor 1 (BANF), CXCL10, leukocyte cell derived chemotaxin 2 (LECT2), Zymogen granule membrane protein 16 (ZG16) and Cathelicidin-derived antimicrobial peptide 2 (Cathelicidin) . b Relative gene expression analysed by qPCR of interleukin 4/13 (IL4/13), interleukin 17A (IL17A), interleukin 8 (IL8), and interferon gamma (IFNγ). c Relative gene expression analysed by qPCR of complement C3 (C3) and myeloperoxidase (MPO)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4862074&req=5

Fig4: Relative gene expression analysed by qPCR and microarray (MA) in skin behind dorsal fin from four groups of L. salmonis-infected Atlantic salmon fed different diets; not-infected high dose (NI-HD), infected control (I-C), infected low dose (I-LD) and infected high dose (I-HD). Relative gene expression is presented as ± fold difference. Bars represent mean fold ± SEM compared to not-infected control fish, NI-C. Number of fish in each qPCR group is 9 and 5 in MA analysis. One-way ANOVA followed by post-hoc Tukey’s multiple comparisons tests was performed between groups and control. Asterisks above bars denote significant differences between groups and control: ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05. Joined brackets show significant differences between experimental groups. The average correlation coefficient between MA and qPCR data was 0.8. a Relative gene expression of barrier-to-autointegration factor 1 (BANF), CXCL10, leukocyte cell derived chemotaxin 2 (LECT2), Zymogen granule membrane protein 16 (ZG16) and Cathelicidin-derived antimicrobial peptide 2 (Cathelicidin) . b Relative gene expression analysed by qPCR of interleukin 4/13 (IL4/13), interleukin 17A (IL17A), interleukin 8 (IL8), and interferon gamma (IFNγ). c Relative gene expression analysed by qPCR of complement C3 (C3) and myeloperoxidase (MPO)

Mentions: Real time qPCR results are shown in Fig. 4. Expression of genes of interest are shown in Fig. 4b, c and the differential expression of BANF (ANOVA: F(4,40) = 7.350, P = 0.0002), CXCL10 (ANOVA: F(4,40) = 3.147, P = 0.0243), LECT2 (ANOVA: F(4,40) = 7.171, P = 0.0002), ZG16 (ANOVA: F(4,40) = 2,214, P = 0.0848) and cathelicidin (ANOVA: F(4,40) = 5.421, P = 0.0014) measured by the array, were validated by qPCR (Fig. 4a). Both diet and lice infection modulated skin transcriptional responses related to immunity. For most pro-inflammatory genes expression was lowest in I-C (Fig. 4b). qPCR analysis confirmed that fish groups exposed to GLs-diets had a significantly higher increase in interferons namely IFNy, compared to the NI-C group (ANOVA: F(4,40) = 4.377, P = 0.0050; NI-HD vs NI-C: P = 0.04; I-LD vs NI-C: P = 0.01; I-HD vs NI-C: P = 0.0070). The almost double increase in the I-HD group of complement component C3 [55] (Fig. 4c) (ANOVA: F(4,40) = 9.761, P < 0.0001; I-C vs I-HD: P = 0.76) and neutrophil attractant IL8 [56] (Fig. 4b) (ANOVA: F(4,40) = 19.24, P < 0.0001; I-C vs I-HD: P = 0.145), compared to I-C group was also observed. Expression of the neutrophil marker myeloperoxidase (MPO) [57] (Fig. 4c) (ANOVA: F(4,40) = 5.3, P = 0.0016) and neutrophil chemoattractant IL17A [58, 59] (Fig. 4b) (ANOVA: F(4,40) = 3.088, P = 0.026) was remarkable; they were both suppressed in NI-HD but most highly induced upon infection in fish exposed to GLs-enriched feeds. Interestingly, IL4/13, a putative Th2 cytokine in fish [60] (Fig. 4b) was found to be most highly induced in I-HD (ANOVA: F(4,40) = 19.66, P < 0.0001; I-HD vs NI-C: P < 0.0001), likely suggesting the need to counteract Type 1 immunity and fine tune highly pro-inflammatory immune responses.Fig. 4


Dietary phytochemicals modulate skin gene expression profiles and result in reduced lice counts after experimental infection in Atlantic salmon.

Jodaa Holm H, Wadsworth S, Bjelland AK, Krasnov A, Evensen Ø, Skugor S - Parasit Vectors (2016)

Relative gene expression analysed by qPCR and microarray (MA) in skin behind dorsal fin from four groups of L. salmonis-infected Atlantic salmon fed different diets; not-infected high dose (NI-HD), infected control (I-C), infected low dose (I-LD) and infected high dose (I-HD). Relative gene expression is presented as ± fold difference. Bars represent mean fold ± SEM compared to not-infected control fish, NI-C. Number of fish in each qPCR group is 9 and 5 in MA analysis. One-way ANOVA followed by post-hoc Tukey’s multiple comparisons tests was performed between groups and control. Asterisks above bars denote significant differences between groups and control: ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05. Joined brackets show significant differences between experimental groups. The average correlation coefficient between MA and qPCR data was 0.8. a Relative gene expression of barrier-to-autointegration factor 1 (BANF), CXCL10, leukocyte cell derived chemotaxin 2 (LECT2), Zymogen granule membrane protein 16 (ZG16) and Cathelicidin-derived antimicrobial peptide 2 (Cathelicidin) . b Relative gene expression analysed by qPCR of interleukin 4/13 (IL4/13), interleukin 17A (IL17A), interleukin 8 (IL8), and interferon gamma (IFNγ). c Relative gene expression analysed by qPCR of complement C3 (C3) and myeloperoxidase (MPO)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4862074&req=5

Fig4: Relative gene expression analysed by qPCR and microarray (MA) in skin behind dorsal fin from four groups of L. salmonis-infected Atlantic salmon fed different diets; not-infected high dose (NI-HD), infected control (I-C), infected low dose (I-LD) and infected high dose (I-HD). Relative gene expression is presented as ± fold difference. Bars represent mean fold ± SEM compared to not-infected control fish, NI-C. Number of fish in each qPCR group is 9 and 5 in MA analysis. One-way ANOVA followed by post-hoc Tukey’s multiple comparisons tests was performed between groups and control. Asterisks above bars denote significant differences between groups and control: ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05. Joined brackets show significant differences between experimental groups. The average correlation coefficient between MA and qPCR data was 0.8. a Relative gene expression of barrier-to-autointegration factor 1 (BANF), CXCL10, leukocyte cell derived chemotaxin 2 (LECT2), Zymogen granule membrane protein 16 (ZG16) and Cathelicidin-derived antimicrobial peptide 2 (Cathelicidin) . b Relative gene expression analysed by qPCR of interleukin 4/13 (IL4/13), interleukin 17A (IL17A), interleukin 8 (IL8), and interferon gamma (IFNγ). c Relative gene expression analysed by qPCR of complement C3 (C3) and myeloperoxidase (MPO)
Mentions: Real time qPCR results are shown in Fig. 4. Expression of genes of interest are shown in Fig. 4b, c and the differential expression of BANF (ANOVA: F(4,40) = 7.350, P = 0.0002), CXCL10 (ANOVA: F(4,40) = 3.147, P = 0.0243), LECT2 (ANOVA: F(4,40) = 7.171, P = 0.0002), ZG16 (ANOVA: F(4,40) = 2,214, P = 0.0848) and cathelicidin (ANOVA: F(4,40) = 5.421, P = 0.0014) measured by the array, were validated by qPCR (Fig. 4a). Both diet and lice infection modulated skin transcriptional responses related to immunity. For most pro-inflammatory genes expression was lowest in I-C (Fig. 4b). qPCR analysis confirmed that fish groups exposed to GLs-diets had a significantly higher increase in interferons namely IFNy, compared to the NI-C group (ANOVA: F(4,40) = 4.377, P = 0.0050; NI-HD vs NI-C: P = 0.04; I-LD vs NI-C: P = 0.01; I-HD vs NI-C: P = 0.0070). The almost double increase in the I-HD group of complement component C3 [55] (Fig. 4c) (ANOVA: F(4,40) = 9.761, P < 0.0001; I-C vs I-HD: P = 0.76) and neutrophil attractant IL8 [56] (Fig. 4b) (ANOVA: F(4,40) = 19.24, P < 0.0001; I-C vs I-HD: P = 0.145), compared to I-C group was also observed. Expression of the neutrophil marker myeloperoxidase (MPO) [57] (Fig. 4c) (ANOVA: F(4,40) = 5.3, P = 0.0016) and neutrophil chemoattractant IL17A [58, 59] (Fig. 4b) (ANOVA: F(4,40) = 3.088, P = 0.026) was remarkable; they were both suppressed in NI-HD but most highly induced upon infection in fish exposed to GLs-enriched feeds. Interestingly, IL4/13, a putative Th2 cytokine in fish [60] (Fig. 4b) was found to be most highly induced in I-HD (ANOVA: F(4,40) = 19.66, P < 0.0001; I-HD vs NI-C: P < 0.0001), likely suggesting the need to counteract Type 1 immunity and fine tune highly pro-inflammatory immune responses.Fig. 4

Bottom Line: Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth.In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Veterinary Medicine and Biosciences, Sea Lice Research Centre, Norwegian University of Life Sciences, PO Box 8146 Dep, 0033, Oslo, Norway.

ABSTRACT

Background: The use of phytochemicals is a promising solution in biological control against salmon louse (Lepeophtheirus salmonis). Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth. The aim of this study was to investigate if Atlantic salmon fed two different doses of glucosinolate-enriched feeds would be protected against lice infection. The effects of feeding high dose of glucosinolates before the infection, and of high and low doses five weeks into the infection were studied.

Methods: Skin was screened by 15 k oligonucleotide microarray and qPCR.

Results: A 25 % reduction (P < 0.05) in lice counts was obtained in the low dose group and a 17 % reduction in the high dose group compared to fish fed control feed. Microarray analysis revealed induction of over 50 interferon (IFN)-related genes prior to lice infection. Genes upregulated five weeks into the infection in glucosinolate-enriched dietary groups included Type 1 pro-inflammatory factors, antimicrobial and acute phase proteins, extracellular matrix remodeling proteases and iron homeostasis regulators. In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.

Conclusions: Atlantic salmon fed glucosinolates had a significantly lower number of sea lice at the end of the experimental challenge. Feeding glucosinolates coincided with increased expression of IFN-related genes, and higher expression profiles of Type 1 immune genes late into the infection. In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.

No MeSH data available.


Related in: MedlinePlus