We tested the hypothesis that p42/44MAPK and p38MAPK (mitogen-activated protein kinases; MAPK) signaling pathways regulate endothelial cell permeability to macromolecules. Passage 2-4 human umbilical vein endothelial cells (HUVEC) were grown to confluence on fibronectin-coated Snapwell membranes. The flux of fluorescein isothiocyanate-labeled dextran-70 across the HUVEC monolayers served to determine permeability. Application of 1 mM 8-bromo 3′ 5′ -cyclic guanosine monophosphate (8-Br - cGMP) increased permeability from 7.0 ± 1.6 × 10-6 to 12.5 ± 2.8 × 10-6 cm/s (P < 0.05). Pretreatment of HUVEC for 60 min with a selective p42/44MAPK inhibitor (AG126 at 2.7 and 27 μM) blocked 8-Br-cGMP-induced hyperpermeability. However, inhibition of p38MAPK (SB203580 at 0.6 μM) did not influence the cGMP-induced hyperpermeability response. AG126, administered at 27 μM, decreased baseline permeability from 7.9 ± 0.5 × 10-6 to 5.9 ± 0.5 × 10-6 cm/s (P < 0.05). Our results indicate that the p42/44MAPK signaling pathway is important in the regulation of baseline permeability and cGMP-induced hyperpermeability.
All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine
- Cell Biology
- Endothelial Cells
- MAP kinases
- Microvascular permeability
- Nitric oxide signaling pathways