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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

Sensitization protocol and antisense oligonucleotide (ASO) administration. Oligonucleotide was administered intranasally one hour before house dust mite (HDM). Twenty-four hours after the last challenge, pulmonary function was assessed by unrestrained whole body plethysmography. Animals were sacrificed the following day and samples were taken.
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Figure 1: Sensitization protocol and antisense oligonucleotide (ASO) administration. Oligonucleotide was administered intranasally one hour before house dust mite (HDM). Twenty-four hours after the last challenge, pulmonary function was assessed by unrestrained whole body plethysmography. Animals were sacrificed the following day and samples were taken.

Mentions: An antisense oligonucleotide strategy was used to selectively down-regulate the production of lung COX-2 mRNA but not COX-1 mRNA. One day before initiating exposure to HDM, and up to two days after withdrawing the allergen, the mice received intranasal saline (untreated), control mismatched antisense oligonucleotide, or selective COX-2 antisense oligonucleotide at 20 μg/mouse (Figure 1). On the days both products were administered, the treatment was always provided one hour before administering the HDM extract. The COX-2-selective oligonucleotide sequence (IK6 antisense oligonucleotide, 5'GGAGTGGGAGGCACTTGC3') was taken from Khan et al. [30]. The control oligonucleotide contained a 7-base mismatched sequence (5'GGACTAGGTTCAAGTTGC3'). Both oligonucleotides were synthesized with a phosphorothioate backbone to improve resistance to endonucleases. Four experimental groups of mice were therefore established (n = 12 per group): (1) untreated non-sensitized, (2) untreated HDM-sensitized, (3) HDM-sensitized treated with a non-specific control oligonucleotide, and (4) HDM-sensitized treated with an antisense oligonucleotide targeting COX-2. For COX-2 mRNA expression, an additional group was included: non-sensitized treated with the COX-2-targeted antisense oligonucleotide (n = 12).


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)

Sensitization protocol and antisense oligonucleotide (ASO) administration. Oligonucleotide was administered intranasally one hour before house dust mite (HDM). Twenty-four hours after the last challenge, pulmonary function was assessed by unrestrained whole body plethysmography. Animals were sacrificed the following day and samples were taken.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: Sensitization protocol and antisense oligonucleotide (ASO) administration. Oligonucleotide was administered intranasally one hour before house dust mite (HDM). Twenty-four hours after the last challenge, pulmonary function was assessed by unrestrained whole body plethysmography. Animals were sacrificed the following day and samples were taken.
Mentions: An antisense oligonucleotide strategy was used to selectively down-regulate the production of lung COX-2 mRNA but not COX-1 mRNA. One day before initiating exposure to HDM, and up to two days after withdrawing the allergen, the mice received intranasal saline (untreated), control mismatched antisense oligonucleotide, or selective COX-2 antisense oligonucleotide at 20 μg/mouse (Figure 1). On the days both products were administered, the treatment was always provided one hour before administering the HDM extract. The COX-2-selective oligonucleotide sequence (IK6 antisense oligonucleotide, 5'GGAGTGGGAGGCACTTGC3') was taken from Khan et al. [30]. The control oligonucleotide contained a 7-base mismatched sequence (5'GGACTAGGTTCAAGTTGC3'). Both oligonucleotides were synthesized with a phosphorothioate backbone to improve resistance to endonucleases. Four experimental groups of mice were therefore established (n = 12 per group): (1) untreated non-sensitized, (2) untreated HDM-sensitized, (3) HDM-sensitized treated with a non-specific control oligonucleotide, and (4) HDM-sensitized treated with an antisense oligonucleotide targeting COX-2. For COX-2 mRNA expression, an additional group was included: non-sensitized treated with the COX-2-targeted antisense oligonucleotide (n = 12).

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