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An intranasal selective antisense oligonucleotide impairs lung cyclooxygenase-2 production and improves inflammation, but worsens airway function, in house dust mite sensitive mice.

Torres R, Herrerias A, Serra-Pagès M, Roca-Ferrer J, Pujols L, Marco A, Picado C, de Mora F - Respir. Res. (2008)

Bottom Line: Finally, mRNA levels of hPGD synthase remained unchanged.Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients.This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pneumology and Respiratory Allergy, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, Spain. rosa.torres@uab.cat

ABSTRACT

Background: Despite its reported pro-inflammatory activity, cyclooxygenase (COX)-2 has been proposed to play a protective role in asthma. Accordingly, COX-2 might be down-regulated in the airway cells of asthmatics. This, together with results of experiments to assess the impact of COX-2 blockade in ovalbumin (OVA)-sensitized mice in vivo, led us to propose a novel experimental approach using house dust mite (HDM)-sensitized mice in which we mimicked altered regulation of COX-2.

Methods: Allergic inflammation was induced in BALBc mice by intranasal exposure to HDM for 10 consecutive days. This model reproduces spontaneous exposure to aeroallergens by asthmatic patients. In order to impair, but not fully block, COX-2 production in the airways, some of the animals received an intranasal antisense oligonucleotide. Lung COX-2 expression and activity were measured along with bronchovascular inflammation, airway reactivity, and prostaglandin production.

Results: We observed impaired COX-2 mRNA and protein expression in the lung tissue of selective oligonucleotide-treated sensitized mice. This was accompanied by diminished production of mPGE synthase and PGE2 in the airways. In sensitized mice, the oligonucleotide induced increased airway hyperreactivity (AHR) to methacholine, but a substantially reduced bronchovascular inflammation. Finally, mRNA levels of hPGD synthase remained unchanged.

Conclusion: Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients. This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened. This approach will provide insights into the differential regulation of inflammation and lung function in asthma, and will help identify pharmacological targets within the COX-2/PG system.

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Related in: MedlinePlus

Airway reactivity to increasing concentrations of aerosolized methacholine. Airway reactivity is shown in non-sensitized mice (white circles), untreated sensitized mice (white squares), control mismatched oligonucleotide-treated sensitized mice (grey squares), and selective COX-2 antisense sensitized mice (black squares). Two-way analysis of variance was used to compare the curves. The COX-2 antisense oligonucleotide (ASO)-treated mice showed a significant increase in AHR to methacholine compared with both untreated and control oligonucleotide-treated sensitized mice. Data are shown as the mean ± SEM (**p < 0.01, ***p < 0.005). ASO: antisense oligonucleotide, MM: mismatched oligonucleotide (n = 12).
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Figure 4: Airway reactivity to increasing concentrations of aerosolized methacholine. Airway reactivity is shown in non-sensitized mice (white circles), untreated sensitized mice (white squares), control mismatched oligonucleotide-treated sensitized mice (grey squares), and selective COX-2 antisense sensitized mice (black squares). Two-way analysis of variance was used to compare the curves. The COX-2 antisense oligonucleotide (ASO)-treated mice showed a significant increase in AHR to methacholine compared with both untreated and control oligonucleotide-treated sensitized mice. Data are shown as the mean ± SEM (**p < 0.01, ***p < 0.005). ASO: antisense oligonucleotide, MM: mismatched oligonucleotide (n = 12).

Mentions: Increasing doses of methacholine induced a dose-dependent rise in Penh in all experimental groups (Figure 4). The Penh increase was higher in the HDM-sensitized mice than in the non-sensitized mice, revealing the induction of AHR in the HDM-sensitized animals. As shown in Figure 4, untreated and control oligonucleotide-treated sensitized mice had almost identical responses to the bronchoconstrictor. However, AHR was significantly higher in the selective COX-2 oligonucleotide-treated mice, where the Penh value at the maximum methacholine concentration (100 mg/ml) was almost twice that found in the untreated or mismatched control-treated sensitized animals (7.40 ± 1.62 vs 14.12 ± 2.75).


An intranasal selective antisense oligonucleotide impairs lung cyclooxygenase-2 production and improves inflammation, but worsens airway function, in house dust mite sensitive mice.

Torres R, Herrerias A, Serra-Pagès M, Roca-Ferrer J, Pujols L, Marco A, Picado C, de Mora F - Respir. Res. (2008)

Airway reactivity to increasing concentrations of aerosolized methacholine. Airway reactivity is shown in non-sensitized mice (white circles), untreated sensitized mice (white squares), control mismatched oligonucleotide-treated sensitized mice (grey squares), and selective COX-2 antisense sensitized mice (black squares). Two-way analysis of variance was used to compare the curves. The COX-2 antisense oligonucleotide (ASO)-treated mice showed a significant increase in AHR to methacholine compared with both untreated and control oligonucleotide-treated sensitized mice. Data are shown as the mean ± SEM (**p < 0.01, ***p < 0.005). ASO: antisense oligonucleotide, MM: mismatched oligonucleotide (n = 12).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2600823&req=5

Figure 4: Airway reactivity to increasing concentrations of aerosolized methacholine. Airway reactivity is shown in non-sensitized mice (white circles), untreated sensitized mice (white squares), control mismatched oligonucleotide-treated sensitized mice (grey squares), and selective COX-2 antisense sensitized mice (black squares). Two-way analysis of variance was used to compare the curves. The COX-2 antisense oligonucleotide (ASO)-treated mice showed a significant increase in AHR to methacholine compared with both untreated and control oligonucleotide-treated sensitized mice. Data are shown as the mean ± SEM (**p < 0.01, ***p < 0.005). ASO: antisense oligonucleotide, MM: mismatched oligonucleotide (n = 12).
Mentions: Increasing doses of methacholine induced a dose-dependent rise in Penh in all experimental groups (Figure 4). The Penh increase was higher in the HDM-sensitized mice than in the non-sensitized mice, revealing the induction of AHR in the HDM-sensitized animals. As shown in Figure 4, untreated and control oligonucleotide-treated sensitized mice had almost identical responses to the bronchoconstrictor. However, AHR was significantly higher in the selective COX-2 oligonucleotide-treated mice, where the Penh value at the maximum methacholine concentration (100 mg/ml) was almost twice that found in the untreated or mismatched control-treated sensitized animals (7.40 ± 1.62 vs 14.12 ± 2.75).

Bottom Line: Finally, mRNA levels of hPGD synthase remained unchanged.Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients.This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Pneumology and Respiratory Allergy, Hospital Clínic, IDIBAPS, Universitat de Barcelona, Barcelona, Spain. rosa.torres@uab.cat

ABSTRACT

Background: Despite its reported pro-inflammatory activity, cyclooxygenase (COX)-2 has been proposed to play a protective role in asthma. Accordingly, COX-2 might be down-regulated in the airway cells of asthmatics. This, together with results of experiments to assess the impact of COX-2 blockade in ovalbumin (OVA)-sensitized mice in vivo, led us to propose a novel experimental approach using house dust mite (HDM)-sensitized mice in which we mimicked altered regulation of COX-2.

Methods: Allergic inflammation was induced in BALBc mice by intranasal exposure to HDM for 10 consecutive days. This model reproduces spontaneous exposure to aeroallergens by asthmatic patients. In order to impair, but not fully block, COX-2 production in the airways, some of the animals received an intranasal antisense oligonucleotide. Lung COX-2 expression and activity were measured along with bronchovascular inflammation, airway reactivity, and prostaglandin production.

Results: We observed impaired COX-2 mRNA and protein expression in the lung tissue of selective oligonucleotide-treated sensitized mice. This was accompanied by diminished production of mPGE synthase and PGE2 in the airways. In sensitized mice, the oligonucleotide induced increased airway hyperreactivity (AHR) to methacholine, but a substantially reduced bronchovascular inflammation. Finally, mRNA levels of hPGD synthase remained unchanged.

Conclusion: Intranasal antisense therapy against COX-2 in vivo mimicked the reported impairment of COX-2 regulation in the airway cells of asthmatic patients. This strategy revealed an unexpected novel dual effect: inflammation was improved but AHR worsened. This approach will provide insights into the differential regulation of inflammation and lung function in asthma, and will help identify pharmacological targets within the COX-2/PG system.

Show MeSH
Related in: MedlinePlus