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Arthritis suppression by NADPH activation operates through an interferon-beta pathway.

Olofsson P, Nerstedt A, Hultqvist M, Nilsson EC, Andersson S, Bergelin A, Holmdahl R - BMC Biol. (2007)

Bottom Line: This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA).Importantly, these two molecular pathways were also confirmed to differentiate between the arthritis-susceptible dark agouti (DA) rat, (with an Ncf-1DA allele that allows only low oxidative burst), and the arthritis-protected DA.Ncf-1E3 rat (with an Ncf1E3 allele that allows a stronger oxidative burst).Interestingly, the treatment led to a restoration of the oxidative-burst effect and induction of a strikingly similar IFN-beta-dependent pathway, as seen with the disease-protective Ncf1 polymorphism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biovitrum AB, Arvid Wallgrens Backe 20, Göteborg, Sweden. peter.olofsson@biovitrum.com

ABSTRACT

Background: A polymorphism in the activating component of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, neutrophil cytosolic factor 1 (NCF1), has previously been identified as a regulator of arthritis severity in mice and rats. This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA). We have recently shown that compounds inducing NCF1-dependent oxidative burst, e.g. phytol, have a strong ameliorating effect on arthritis in rats. However, the underlying molecular mechanism is still not clearly understood. The aim of this study was to use gene-expression profiling to understand the protective effect against arthritis of activation of NADPH oxidase in the immune system.

Results: Subcutaneous administration of phytol leads to an accumulation of the compound in the inguinal lymph nodes, with peak levels being reached approximately 10 days after administration. Hence, global gene-expression profiling on inguinal lymph nodes was performed 10 days after the induction of pristane-induced arthritis (PIA) and phytol administration. The differentially expressed genes could be divided into two pathways, consisting of genes regulated by different interferons. IFN-gamma regulated the pathway associated with arthritis development, whereas IFN-beta regulated the pathway associated with disease protection through phytol. Importantly, these two molecular pathways were also confirmed to differentiate between the arthritis-susceptible dark agouti (DA) rat, (with an Ncf-1DA allele that allows only low oxidative burst), and the arthritis-protected DA.Ncf-1E3 rat (with an Ncf1E3 allele that allows a stronger oxidative burst).

Conclusion: Naturally occurring genetic polymorphisms in the Ncf-1 gene modulate the activity of the NADPH oxidase complex, which strongly regulates the severity of arthritis. We now show that the Ncf-1 allele that enhances oxidative burst and protects against arthritis is operating through an IFN-beta-associated pathway, whereas the arthritis-driving allele operates through an IFN-gamma-associated pathway. Treatment of arthritis-susceptible rats with an NADPH oxidase-activating substance, phytol, protects against arthritis. Interestingly, the treatment led to a restoration of the oxidative-burst effect and induction of a strikingly similar IFN-beta-dependent pathway, as seen with the disease-protective Ncf1 polymorphism.

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Hierarchical clustering of differentially expressed genes in phytol-treated compared with pristane-treated rats. Euclidean distance was used as a similarity measure. Each column represents one individual rat, and each horizontal stripe represents a gene transcript. The Affymetrix probe set identification, the gene symbol, the average fold change (FC) for phytol versus pristane together with the p value, and the average fold change for phytol/pristane versus pristane and its p value are given to the right. The colors in the clustering represent the gene-expression level in each individual rat compared with the average expression in all arrays, where green indicates low expression and red represents high expression.
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Figure 2: Hierarchical clustering of differentially expressed genes in phytol-treated compared with pristane-treated rats. Euclidean distance was used as a similarity measure. Each column represents one individual rat, and each horizontal stripe represents a gene transcript. The Affymetrix probe set identification, the gene symbol, the average fold change (FC) for phytol versus pristane together with the p value, and the average fold change for phytol/pristane versus pristane and its p value are given to the right. The colors in the clustering represent the gene-expression level in each individual rat compared with the average expression in all arrays, where green indicates low expression and red represents high expression.

Mentions: Previous results have shown that the NADPH oxidase activator phytol has ameliorating properties on arthritis when administrated prior to arthritis induction and when given as therapeutic treatment [20]. To obtain a molecular understanding of the protective effects of phytol on PIA, four groups of animals were subjected to different conditions; (i) induced arthritis by injection with pristane, (ii) injection with phytol, (iii) injection with both pristane and phytol, and (iv) no treatment. All animals were killed close to disease onset, i.e.10 days after administration. Global gene-expression profiling using chip arrays (Genechip®;Affymetrix, Santa Clara, CA, USA) was performed on the collected inguinal lymph nodes from the described animals. The gene-expression pattern was quite different between treated rats and naïve controls. Comparing any of the group of treated animals and untreated animals, > 350 differentially expressed genes were detected (at significance level p < 0.05 and absolute fold change > 1.4; data not shown). However, as the most interesting differences were to be found between the different treatments, the analysis focused on these groups. When comparing phytol-treated versus pristane-treated animals, the expression of 29 genes was significantly changed (p < 0.05, with absolute fold change > 1.4). Of these 29 genes, 13 showed expression in phytol-treated rats, whereas 16 genes showed higher expression in pristane-treated rats (Figure 2). Because more complex gene induction was observed in animals given phytol plus pristane, further studies concentrated on analyses of single-compound administrations.


Arthritis suppression by NADPH activation operates through an interferon-beta pathway.

Olofsson P, Nerstedt A, Hultqvist M, Nilsson EC, Andersson S, Bergelin A, Holmdahl R - BMC Biol. (2007)

Hierarchical clustering of differentially expressed genes in phytol-treated compared with pristane-treated rats. Euclidean distance was used as a similarity measure. Each column represents one individual rat, and each horizontal stripe represents a gene transcript. The Affymetrix probe set identification, the gene symbol, the average fold change (FC) for phytol versus pristane together with the p value, and the average fold change for phytol/pristane versus pristane and its p value are given to the right. The colors in the clustering represent the gene-expression level in each individual rat compared with the average expression in all arrays, where green indicates low expression and red represents high expression.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1884140&req=5

Figure 2: Hierarchical clustering of differentially expressed genes in phytol-treated compared with pristane-treated rats. Euclidean distance was used as a similarity measure. Each column represents one individual rat, and each horizontal stripe represents a gene transcript. The Affymetrix probe set identification, the gene symbol, the average fold change (FC) for phytol versus pristane together with the p value, and the average fold change for phytol/pristane versus pristane and its p value are given to the right. The colors in the clustering represent the gene-expression level in each individual rat compared with the average expression in all arrays, where green indicates low expression and red represents high expression.
Mentions: Previous results have shown that the NADPH oxidase activator phytol has ameliorating properties on arthritis when administrated prior to arthritis induction and when given as therapeutic treatment [20]. To obtain a molecular understanding of the protective effects of phytol on PIA, four groups of animals were subjected to different conditions; (i) induced arthritis by injection with pristane, (ii) injection with phytol, (iii) injection with both pristane and phytol, and (iv) no treatment. All animals were killed close to disease onset, i.e.10 days after administration. Global gene-expression profiling using chip arrays (Genechip®;Affymetrix, Santa Clara, CA, USA) was performed on the collected inguinal lymph nodes from the described animals. The gene-expression pattern was quite different between treated rats and naïve controls. Comparing any of the group of treated animals and untreated animals, > 350 differentially expressed genes were detected (at significance level p < 0.05 and absolute fold change > 1.4; data not shown). However, as the most interesting differences were to be found between the different treatments, the analysis focused on these groups. When comparing phytol-treated versus pristane-treated animals, the expression of 29 genes was significantly changed (p < 0.05, with absolute fold change > 1.4). Of these 29 genes, 13 showed expression in phytol-treated rats, whereas 16 genes showed higher expression in pristane-treated rats (Figure 2). Because more complex gene induction was observed in animals given phytol plus pristane, further studies concentrated on analyses of single-compound administrations.

Bottom Line: This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA).Importantly, these two molecular pathways were also confirmed to differentiate between the arthritis-susceptible dark agouti (DA) rat, (with an Ncf-1DA allele that allows only low oxidative burst), and the arthritis-protected DA.Ncf-1E3 rat (with an Ncf1E3 allele that allows a stronger oxidative burst).Interestingly, the treatment led to a restoration of the oxidative-burst effect and induction of a strikingly similar IFN-beta-dependent pathway, as seen with the disease-protective Ncf1 polymorphism.

View Article: PubMed Central - HTML - PubMed

Affiliation: Biovitrum AB, Arvid Wallgrens Backe 20, Göteborg, Sweden. peter.olofsson@biovitrum.com

ABSTRACT

Background: A polymorphism in the activating component of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex, neutrophil cytosolic factor 1 (NCF1), has previously been identified as a regulator of arthritis severity in mice and rats. This discovery resulted in a search for NADPH oxidase-activating substances as a potential new approach to treat autoimmune disorders such as rheumatoid arthritis (RA). We have recently shown that compounds inducing NCF1-dependent oxidative burst, e.g. phytol, have a strong ameliorating effect on arthritis in rats. However, the underlying molecular mechanism is still not clearly understood. The aim of this study was to use gene-expression profiling to understand the protective effect against arthritis of activation of NADPH oxidase in the immune system.

Results: Subcutaneous administration of phytol leads to an accumulation of the compound in the inguinal lymph nodes, with peak levels being reached approximately 10 days after administration. Hence, global gene-expression profiling on inguinal lymph nodes was performed 10 days after the induction of pristane-induced arthritis (PIA) and phytol administration. The differentially expressed genes could be divided into two pathways, consisting of genes regulated by different interferons. IFN-gamma regulated the pathway associated with arthritis development, whereas IFN-beta regulated the pathway associated with disease protection through phytol. Importantly, these two molecular pathways were also confirmed to differentiate between the arthritis-susceptible dark agouti (DA) rat, (with an Ncf-1DA allele that allows only low oxidative burst), and the arthritis-protected DA.Ncf-1E3 rat (with an Ncf1E3 allele that allows a stronger oxidative burst).

Conclusion: Naturally occurring genetic polymorphisms in the Ncf-1 gene modulate the activity of the NADPH oxidase complex, which strongly regulates the severity of arthritis. We now show that the Ncf-1 allele that enhances oxidative burst and protects against arthritis is operating through an IFN-beta-associated pathway, whereas the arthritis-driving allele operates through an IFN-gamma-associated pathway. Treatment of arthritis-susceptible rats with an NADPH oxidase-activating substance, phytol, protects against arthritis. Interestingly, the treatment led to a restoration of the oxidative-burst effect and induction of a strikingly similar IFN-beta-dependent pathway, as seen with the disease-protective Ncf1 polymorphism.

Show MeSH
Related in: MedlinePlus