Immunohistochemical analysis of endothelial-monocyte-activating polypeptide-II expression in vivo.
Endothelial-monocyte activating polypeptide (EMAP)-II is a novel molecule with cytokine-like pro-inflammatory properties, inducing procoagulant activity on the surface of endothelial cells and monocyte/macrophages in vitro, as well as up-regulating E- and P-selectin expression. EMAP-II is chemotactic for monocytes/macrophages and neutrophils, and stimulates myeloperoxidase release from neutrophils. Injection of EMAP-II into the mouse footpad induces an acute inflammatory response, although some regression occurs in response to direct injection of EMAP-II into murine tumors. Very little is known about the expression of EMAP-II in normal tissues of mice or humans, or about its function in vivo. We developed polyclonal antibodies against EMAP-II using recombinant protein produced in Escherichia coli, and used these antibodies to carry out an immunohistochemical study of the occurrence and distribution of EMAP-II in human tissues. The distribution of EMAP-II protein is relatively restricted, occurring primarily in endocrine organs, in cells of neuroendocrine origin, but also in tissues with high turnover. EMAP-II is strongly expressed in secretory epithelial cells of the thyroid, pancreas, adrenal and salivary glands, among others, as well as in neurons and subsets of monocytes/macrophages. It is also found in the epithelium of the small and large intestines. We conclude that EMAP-II expression is usually, but not always, associated with tissues that display high turnover and high levels of protein synthesis.
Murray
J C
JC
CRC Department of Clinical Oncology, University of Nottingham Laboratory of Molecular Oncology, Nottingham, United Kingdom. cliff.murray@nott.ac.uk
Barnett
G
G
Tas
M
M
Jakobsen
A
A
Brown
J
J
Powe
D
D
Clelland
C
C
D002319:Cardiovascular System / Q000378:metabolism; D016207:Cytokines; D004064:Digestive System / Q000378:metabolism; D004702:Endocrine Glands / Q000378:metabolism; D005835:Genitalia / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014018:Tissue Distribution
D016207:Cytokines; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C077219:small inducible cytokine subfamily E, member 1