Membrane prostaglandin E synthase-1: a novel therapeutic target.
Prostaglandin E(2) (PGE(2)) is the most abundant prostaglandin in the human body. It has a large number of biological actions that it exerts via four types of receptors, EP1-4. PGE(2) is formed from arachidonic acid by cyclooxygenase (COX-1 and COX-2)-catalyzed formation of prostaglandin H(2) (PGH(2)) and further transformation by PGE synthases. The isomerization of the endoperoxide PGH(2) to PGE(2) is catalyzed by three different PGE synthases, viz. cytosolic PGE synthase (cPGES) and two membrane-bound PGE synthases, mPGES-1 and mPGES-2. Of these isomerases, cPGES and mPGES-2 are constitutive enzymes, whereas mPGES-1 is mainly an induced isomerase. cPGES uses PGH(2) produced by COX-1 whereas mPGES-1 uses COX-2-derived endoperoxide. mPGES-2 can use both sources of PGH(2). mPGES-1 is a member of the membrane associated proteins involved in eicosanoid and glutathione metabolism (MAPEG) superfamily. It requires glutathione as an essential cofactor for its activity. mPGES-1 is up-regulated in response to various proinflammatory stimuli with a concomitant increased expression of COX-2. The coordinate increased expression of COX-2 and mPGES-1 is reversed by glucocorticoids. Differences in the kinetics of the expression of the two enzymes suggest distinct regulatory mechanisms for their expression. Studies, mainly from disruption of the mPGES-1 gene in mice, indicate key roles of mPGES-1-generated PGE(2) in female reproduction and in pathological conditions such as inflammation, pain, fever, anorexia, atherosclerosis, stroke, and tumorigenesis. These findings indicate that mPGES-1 is a potential target for the development of therapeutic agents for treatment of several diseases.
Samuelsson
Bengt
B
Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77, Stockholm, Sweden. bengt.samuelsson@ki.se
Morgenstern
Ralf
R
Jakobsson
Per-Johan
PJ
D000818:Animals; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000201:enzymology; D002462:Cell Membrane / Q000201:enzymology; D015232:Dinoprostone / Q000378:metabolism*; D016503:Drug Delivery Systems; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D007249:Inflammation / Q000188:drug therapy / Q000201:enzymology; D019746:Intramolecular Oxidoreductases / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy / Q000201:enzymology; D000071876:Prostaglandin-E Synthases; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D011487:Protein Conformation; D018078:Receptors, Prostaglandin E / Q000235:genetics; D012098:Reproduction
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D018078:Receptors, Prostaglandin E; D011451:Prostaglandin-Endoperoxide Synthases; D019746:Intramolecular Oxidoreductases; C000605862:PTGES protein, human; C000605863:PTGES2 protein, human; D000071876:Prostaglandin-E Synthases; C000605865:Ptges protein, mouse; C000605866:Ptges2 protein, mouse; D015232:Dinoprostone