ABSTRACT
The initial event of hypoxic pulmonary hypertension is acute hypoxic pulmonary vasoconstriction followed by remodeling of pulmonary arteries. Although 15(S)-hydroxyeicosatetraenoic acid [15(S)-HETE] is found to be able to induce hypoxic pulmonary vasoconstriction, role of 15(S)-HETE in pulmonary artery smooth muscle cells (PASMCs) proliferation has been studied less. We sought evidence for a role of 15(S)-HETE in the development of hypoxia-induced pulmonary hypertension. We found that hypoxia enhances 15-lipoxygenase-2 (15-LOX-2) expression and stimulates cultured rabbit PASMCs proliferation. 15(S)-HETE at concentration 0.1 µM stimulated proliferation of PASMCs and induced ERK 1/ERK 2 phosphorylation but had no effect on p38 kinase expression as assessed by Western blotting. 15(S)-HETE-stimulated PASMC proliferation was blocked by the MEK inhibitors PD-98059. Hypoxia (3% O(2))-stimulated PASMC proliferation was blocked by U0126, a MEK inhibitor, as well as by NDGA and CDC, inhibitors of 15-LOX, but not by the p38 MAPK inhibitor SB-202190. We conclude that 15-LOX-2 and its product, 15(S)-HETE, are important intermediates in hypoxia-induced rabbit PASMC proliferation and may participate in hypoxia-induced pulmonary hypertension.
Subject(s)
Arachidonate 15-Lipoxygenase/metabolism , Cell Proliferation , Hydroxyeicosatetraenoic Acids/metabolism , Myocytes, Smooth Muscle/metabolism , Animals , Animals, Newborn , Blotting, Western , Butadienes/pharmacology , Caffeic Acids/pharmacology , Cell Survival/drug effects , Cells, Cultured , Flavonoids/pharmacology , Hydroxyeicosatetraenoic Acids/pharmacology , Hydroxyeicosatetraenoic Acids/physiology , Hypoxia , Lipoxygenase Inhibitors/pharmacology , Masoprocol/pharmacology , Mitogen-Activated Protein Kinase 1/antagonists & inhibitors , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/antagonists & inhibitors , Mitogen-Activated Protein Kinase 3/metabolism , Muscle, Smooth, Vascular/cytology , Myocytes, Smooth Muscle/drug effects , Nitriles/pharmacology , Pulmonary Artery/cytology , Rabbits , Time FactorsABSTRACT
AIM: To construct and express an anti-VEGFR2/anti-CD3 bispecific single-chain antibody (bscVEGFR2×CD3)and to identify its binding specificities to CD3 and VEGFR2. METHODS: The gene encoding anti-VEGFR2/anti-CD3 bispecific single-chain antibody was designed and synthesized. Bispecific single-chain antibody (bsc-Ab) DNA was subcloned into a eukaryotic expression vector pcDNA3.1(+), then transfected into Chinese hamster ovary (CHO) cells and stable expression cell lines were selected. Expressed Bsc-Ab was purified by His-tag affinity chromatography and confirmed by 120 g/L SDS-PAGE and Western blotting. Antigen binding activity of the bsc-Ab was analyzed by FACS. RESULTS: The plasmid DNA containing bispecific single-chain fragments were confirmed. BscVEGFR2×CD3 was secreted by CHO into the supernatant. Six stable expression cell lines were established. The molecular weight of bsc-Ab was correct indicated by SDS-PAGE and Western blotting. The bsc-Ab could specifically bind to CD3(+); jurkat cells and VEGFR2(+); A375 cells. CONCLUSION: An anti-VEGFR2/anti-CD3 bispecific single-chain antibody is successfully constructed and expressed, and the antibody has specific binding capacity to CD3 and VEGFR2.
