The primers used were as follows: HIF-1α (predicted length 343 bp) sense: 5′-TGCTCATCAGTTGCCACTT-3′, antisense: 5′-TGGGCCATTTCTGTGTGTA-3′; HIF-2α used were sense: 5′-GACGGTGACATGATCTTTCTGTC-3′, antisense: 5′-CACTTCATCCTCATGAAGAAGTCAC-3′; VEGF (predicted length; VEGF165: 535 bp and VEGF121: 403 bp) sense: 5′-CCAAGTGGTCCCAGGCTGCACC-3′, antisense: 5′-GGTTAATCGGTCTTTCCGGTGAG-3′, and GAPDH (predicted length 609 bp) sense: 5′-GCCATCAACGACCCCTTCATTGAC-3′, antisense: 5′-ACGGAAGGCCATGCCAGTG AGCTT-3′. PCR reactions were performed in a thermocycler (GeneAmp® PCR System 2400, Applied Biosystems, Foster City, CA, USA).

Quantitative RT-PCR analysis was performed using the LightCycler® FastStart DNA Master SYBR Green I (Roche Daporinad mouse Diagnostics, Mannheim, Germany). The ΔCT-method was used for the calculation of relative changes of mRNA by

LightCycler 480® Multiple Plate Analysis Software (Roche Diagnostics) 55. The data were normalized to the expression of β-actin and was confirmed by quantitative real-time RT-PCR to be ubiquitously and consistently expressed gene among all groups analyzed. The sequences of primers used were as follows: HIF-1α sense: 5′-TGCTCATCAGTTGCCACTT-3′, antisense: 5′-TGGGCCATTTCTGTGTGTA-3′; HIF-2α used were sense: 5′-GACGGTGACATGATCTTTCTGTC-3′, KU-60019 antisense: 5′-CACTTCATCCTCATGAAGAAGTCAC-3′; selleck chemicals VEGF sense: 5′-CCAAGTGGTCCCAGGCTGCACC-3′,

antisense: 5′-GGTTAATCGGTCTTTCCGGTGAG-3′, and β-actin sense: 5′-CAGATCATGTTTGAGAC CTTC-3′ and antisense: 5′-ACTTCATGATGGAATTGAATG-3′. PI3K enzyme activity was measured as described previously 33. The amount of PIP3 produced was quantified by PIP3 competition enzyme immunoassays according to the manufacturer’s protocol (Echelon, Salt Lake City, UT, USA). An inhibitor of HIF-1α, 2ME2 (50 or 100 mg/kg body weight/day), was suspended in 0.5% carboxymethylcellulose (Sigma-Aldrich) and administered by oral gavage six times at 24-h interval on days 19–24, beginning 2 days before the first challenge 56. Cyclopeptidic vascular endothelial growth inhibitor, CBO-P11 (Flt-1; IC50=700 nmol/L, Flk-1/KDR; IC50=1.3 μmol/L, D-Phe-Pro (79–93); Calbiochem-Novobiochem) was used to inhibit VEGF activity. CBO-P11 (2 mg/kg body weight/day) was administered i.p. three times at 24-h interval, beginning at 1 h before the first inhalation. IC87114 (0.1 or 1.0 mg/kg body weight/day) or vehicle control (0.05% DMSO) diluted with 0.9% NaCl was administered in a volume of 50 μL by intratracheal instillation two times to each animal, once on day 21 (1 h before the first airway challenge with OVA) and the second time on day 23 (3 h after the last airway challenge with OVA) 33. Protein expression levels were analyzed by Western blot analysis as described previously 48.