title: Identification of activators of ERK5 transcriptional activity by high-throughput screening and the role of endothelial ERK5 in vasoprotective effects induced by statins and antimalarial agents.
abstract: Because ERK5 inhibits endothelial inflammation and dysfunction, activating ERK5 might be a novel approach to protecting vascular endothelial cells (ECs) against various pathological conditions of the blood vessel. We have identified small molecules that protect ECs via ERK5 activation and determined their contribution to preventing cardiac allograft rejection. Using high-throughput screening, we identified certain statins and antimalarial agents including chloroquine, hydroxychloroquine, and quinacrine as strong ERK5 activators. Pitavastatin enhanced ERK5 transcriptional activity and Kruppel-like factor-2 expression in cultured human and bovine ECs, but these effects were abolished by the depletion of ERK5. Chloroquine and hydroxychloroquine upregulated ERK5 kinase activity and inhibited VCAM-1 expression in an ERK5-dependent but MAPK/ERK kinase 5- and Kruppel-like factor 2/4-independent manner. Leukocyte rolling and vascular reactivity were used to evaluate endothelial function in vivo, and we found that EC-specific ERK5 knockout (ERK5-EKO) mice exhibited increased leukocyte rolling and impaired vascular reactivity, which could not be corrected by pitavastatin. The role of endothelial ERK5 in acute cardiac allograft rejection was also examined by heterotopic grafting of the heart obtained from either wild-type or ERK5-EKO mice into allomismatched recipient mice. A robust increase in both inflammatory gene expression and CD45-positive cell infiltration into the graft was observed. These tissue rejection responses were inhibited by pitavastatin in wild-type but not ERK5-EKO hearts. Our study has identified statins and antimalarial drugs as strong ERK5 activators and shown that ERK5 activation is preventive of endothelial inflammation and dysfunction and acute allograft rejection.
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Nhat-Tu
authors.initials: NT
authors.lastname: Le
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Takei
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Yuki
authors.initials: Y
authors.lastname: Izawa-Ishizawa
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Kyung-Sun
authors.initials: KS
authors.lastname: Heo
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Hakjoo
authors.initials: H
authors.lastname: Lee
authors.affiliation: Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Alan V
authors.initials: AV
authors.lastname: Smrcka
authors.affiliation: Department of Dermatology, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642; and.
authors.forename: Benjamin L
authors.initials: BL
authors.lastname: Miller
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Kyung Ae
authors.initials: KA
authors.lastname: Ko
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Sara
authors.initials: S
authors.lastname: Ture
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Craig
authors.initials: C
authors.lastname: Morrell
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642;
authors.forename: Keigi
authors.initials: K
authors.lastname: Fujiwara
authors.affiliation: Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, 770-8503, Japan jabe@mdanderson.org akaike.masashi@tokushima-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Akaike
authors.affiliation: Aab Cardiovascular Research Institute, School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642; jabe@mdanderson.org akaike.masashi@tokushima-u.ac.jp.
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Abe
mesh_terms: D064591:Allografts; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002417:Cattle; D004730:Endothelium, Vascular / Q000276:immunology* / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D006084:Graft Rejection / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016027:Heart Transplantation; D061307:Human Umbilical Vein Endothelial Cells; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology*; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors / Q000235:genetics / Q000276:immunology; D036904:Leukocyte Rolling / Q000187:drug effects / Q000235:genetics / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D048054:Mitogen-Activated Protein Kinase 7 / Q000235:genetics / Q000276:immunology*; D011804:Quinolines / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects* / Q000276:immunology; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000276:immunology
chemical_list: D000962:Antimalarials; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; C096161:KLF2 protein, human; C498314:Klf2 protein, mouse; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D011804:Quinolines; D019010:Vascular Cell Adhesion Molecule-1; D048054:Mitogen-Activated Protein Kinase 7; C108475:pitavastatin