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Over‐expression of mitogen‐activated protein kinase phosphatase‐2 enhances adhesion molecule expression and protects against apoptosis in human endothelial cells
Author(s) -
AlMutairi Mashael,
AlHarthi Sameer,
Cadalbert Laurence,
Plevin Robin
Publication year - 2010
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.2010.00952.x
Subject(s) - microbiology and biotechnology , p38 mitogen activated protein kinases , biology , cell adhesion molecule , kinase , protein kinase a , phosphorylation , apoptosis , phosphatase , biochemistry
BACKGROUND AND PURPOSE We assessed the effects of over‐expressing the dual‐specific phosphatase, mitogen‐activated protein (MAP) kinase phosphatase‐2 (MKP‐2), in human umbilical vein endothelial cells (HUVECs) on inflammatory protein expression and apoptosis, two key features of endothelial dysfunction in disease. EXPERIMENTAL APPROACHES We infected HUVECs for 40 h with an adenoviral version of MKP‐2 (Adv.MKP‐2). Tumour necrosis factor (TNF)‐α‐stimulated phosphorylation of MAP kinase and protein expression was measured by Western blotting. Cellular apoptosis was assayed by FACS. KEY RESULTS Infection with Adv.MKP‐2 selectively abolished TNF‐α‐mediated c‐Jun‐N‐terminal kinase (JNK) activation and had little effect upon extracellular signal‐regulated kinase or p38 MAP kinase. Adv.MKP‐2 abolished COX‐2 expression, while induction of the endothelial cell adhesion molecules, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), two NFκB‐dependent proteins, was not affected. However, when ICAM and VCAM expression was partly reduced by blockade of the NFκB pathway, Adv.MKP‐2 was able to reverse this inhibition. This correlated with enhanced TNF‐α‐induced loss of the inhibitor of κB (IκB)α loss, a marker of NFκB activation. TNF‐α in combination with NFκB blockade also increased HUVEC apoptosis; this was significantly reversed by Adv.MKP‐2. Protein markers of cellular damage and apoptosis, H2AX phosphorylation and caspase‐3 cleavage, were also reversed by MKP‐2 over‐expression. CONCLUSIONS AND IMPLICATIONS Over‐expression of MKP‐2 had different effects upon the expression of inflammatory proteins due to a reciprocal effect upon JNK and NFκB signalling, and also prevented TNF‐α‐mediated endothelial cell death. These properties may make Adv.MKP‐2 a potentially useful future therapy in cardiovascular diseases where endothelial dysfunction is a feature.