Abstract
Thrombin-induced endothelial cell barrier dysfunction is tightly linked to Ca2+-dependent cytoskeletal protein reorganization. In this study, we found that thrombin increased Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) activities in a Ca2+- and time-dependent manner in bovine pulmonary endothelium with maximal activity at 5 min. Pretreatment with KN-93, a specific CaM kinase II inhibitor, attenuated both thrombin-induced increases in monolayer permeability to albumin and decreases in transendothelial electrical resistance (TER). We next explored potential thrombin-induced CaM kinase II cytoskeletal targets and found that thrombin causes translocation and significant phosphorylation of nonmuscle filamin (ABP-280), which was attenuated by KN-93, whereas thrombin-induced myosin light chain phosphorylation was unaffected. Furthermore, a cell-permeable N-myristoylated synthetic filamin peptide (containing the COOH-terminal CaM kinase II phosphorylation site) attenuated both thrombin-induced filamin phosphorylation and decreases in TER. Together, these studies indicate that CaM kinase II activation and filamin phosphorylation may participate in thrombin-induced cytoskeletal reorganization and endothelial barrier dysfunction.
Original language | English (US) |
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Pages (from-to) | L983-L990 |
Journal | American Journal of Physiology - Lung Cellular and Molecular Physiology |
Volume | 280 |
Issue number | 5 25-5 |
DOIs | |
State | Published - May 2001 |
Externally published | Yes |
Keywords
- Filamin
- Myosin light chain phosphorylation
- Thrombin
- Transendothelial electrical resistance
ASJC Scopus subject areas
- Physiology
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology