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Thrombosis Research 110 (2003) 255 – 258 The William Harvey Research Institute, St. Bartholomew’s and the Royal London School of Medicine, Charterhouse Square, London EC1M 6BQ, UK The therapy of rheumatism began thousands of years ago with the use of decoctions or extracts of herbs or plants such as willow bark or leaves, most of which turned out to contain salicylates. Following the advent of synthetic salicylate, Felix Hoffman, working at the Bayercompany in Germany, made the acetylated form of salicylic acid in 1897. This drug was named ‘‘Aspirin’’ and became the most widely usedmedicine of all time. In 1971, Vane discovered the mechanism by which aspirin exerts its anti-inflammatory, analgesic and antipyreticactions. He proved that aspirin and other non-steroid anti-inflammatory drugs (NSAIDs) inhibit the activity of the enzyme now calledcyclooxygenase (COX) which leads to the formation of prostaglandins (PGs) that cause inflammation, swelling, pain and fever. However, byinhibiting this key enzyme in PG synthesis, the aspirin-like drugs also prevented the production of physiologically important PGs whichprotect the stomach mucosa from damage by hydrochloric acid, maintain kidney function and aggregate platelets when required. Thisconclusion provided a unifying explanation for the therapeutic actions and shared side effects of the aspirin-like drugs. Twenty years later,with the discovery of a second COX gene, it became clear that there are two isoforms of the COX enzyme. The constitutive isoform, COX-1,supports the beneficial homeostatic functions, whereas the inducible isoform, COX-2, becomes upregulated by inflammatory mediators andits products cause many of the symptoms of inflammatory diseases such as rheumatoid and osteoarthritis.
D 2003 Published by Elsevier Ltd.
Keywords: Aspirin; Cyclooxygenases; Bayer; Inflammation; Thromboxane; Anaphylaxis; Platelets Aspirin is the most widely used drug in the world. An many years to treat his arthritis and had recently discovered aspirin a day doubles the chances of a long life. Studies have that he could no longer take the drug without vomiting.
shown that a regular dose of aspirin for the over 50s can Impelled then by filial affection as well as by dedication to prolong life since aspirin reduces the risk of many diseases his job, Hoffman searched through the scientific literature associated with aging. The history of aspirin goes back and found a way of acetylating the hydroxyl group on the many thousands of years to the early uses of decoctions or benzene ring of salicylic acid to form acetylsalicylic acid.
preparations of plants that contain salicylate. Maclagan After initial laboratory tests, Hoffman’s father was given the used Salicin, the bitter principle of the common white drug; it was pronounced effective and later confirmed as willow, successfully in 1874 to reduce the fever, pain and such by a more impartial clinical trial.
inflammation of rheumatic fever. Also in 1874, the com- The name ‘‘Aspirin’’ was given to the new drug by mercial organic synthesis of salicylic acid was formulated Bayer’s chief pharmacologist, Heinrich Dreser who was by Kolbe and his colleagues and led to the founding of the anxious to find a name that could not possibly be confused with salicylic acid. At least two accounts are given for The success of salicylic acid prompted the pharmaceuti- Dreser’s choice of name; some authorities maintain that the cal manufacturing house of Frederick Bayer to actively drug was named after St Aspirinius, an early Neapolitan search for a derivative of comparable or better efficacy to bishop who was the patron saint against headaches. A more salicylic acid. Arthur Eichengru¨n, head of the chemical prosaic explanation is that the name was derived from research laboratories at Bayer in 1895, assigned this task Spiraea, which is the Linnaean name for the genus of plants to a young chemist named Felix Hoffman. Hoffman also to which meadowsweet belongs. Meadowsweet contains had personal reasons for wanting a more acceptable salicylic salicylaldehyde, which can be oxidised to salicylic acid.
acid derivative; his father had been taking salicylic acid for According to this explanation, the acid derived from Spi-raea became ‘‘Spirsau¨re’’ in German. Acetylation of Spir-sau¨re produced ‘‘Acetylspisau¨re’’, which was soon * Corresponding author. Tel.: +44-207-882-6179; fax: +44-207-882- 0049-3848/$ - see front matter D 2003 Published by Elsevier Ltd.
doi:10.1016/S0049-3848(03)00379-7 J.R. Vane, R.M. Botting / Thrombosis Research 110 (2003) 255–258 Of course, it is quite possible that Dreser was aware of glandin (PGs) researchers. Piper and Vane used isolated both possible derivations and that the ambiguous name was lungs perfused with Krebs’ solution from sensitised guinea a deliberate and felicitous contrivance. Of interest, pigs. The purpose was to detect substances released during ‘‘Euˆsparin’’ was suggested in the original document as an the anaphylactic reaction, including histamine and SRS-A, both of which had been known for many years as possiblemediators of anaphylaxis.
They used the technique of continuous bioassay with the 1. Early explanations for the action of aspirin cascade bioassay system developed by Vane in themiddle 1960s for use with blood or artificial salt solution.
Before 1971, little was known about the real mechanism As expected, Piper and Vane found the release during of action of aspirin-like drugs. They produced an anti- anaphylaxis of histamine and SRS-A, but they also found inflammatory effect that was qualitatively and quantitatively some previously unreported substances: PGs, (mainly PGE2 different from that of the anti-inflammatory steroids, and but some PGF2a) and another, very ephemeral substance their analgesic action was of a different nature than that that they called ‘‘rabbit aorta contracting substance’’ (RCS) produced by opiates. Aspirin-like drugs are weak analgesics based on the assay tissue that identified it. In the lung compared with ‘‘strong’’ narcotic analgesics like morphine.
perfusate RCS had a half-life of about 2 min; even when They are effective in clinical pain of low or moderate but cooled to a few degrees above freezing, it remained stable not high intensity such as postoperative pain, osteoarthritis, for no more than 20 min. It was identified in 1975 as rheumatoid arthritis, ankylosing spondilytis and some forms of headache Aspirin-like drugs are effective in experi- It was RCS that provided the first clue to the relation mental models involving the induction of a previous in- between aspirin and the PGs. In the course of further flammatory state and block the delayed stretching response experiments involving RCS, Piper and Vane discovered that induced with an intraperitoneal injection of phenylbenzo- in some preparations RCS was released by bradykinin. This quinone or dilute acetic acid in mice. They are not effective suggested that aspirin’s ability to minimise some effects of against nociception of short duration induced by pinching or bradykinin might be due to its blocking of RCS release. This stimulating the tail or toes of mouse, rat or guinea pig.
idea was confirmed when Piper and Vane presented Guzman et al. and Lim et al. provided definitive experimental evidence that the release of RCS from isolated evidence of the peripheral analgesic activity of aspirin-like guinea pig lungs during anaphylaxis was blocked by aspirin.
drugs. What then does aspirin do in the periphery to decrease These guinea pig lung experiments also indicated that nociception or pain? Many biochemical effects of aspirin- whenever aspirin blocked RCS release, there was a smaller like drugs have been documented and theories based on these contraction of the tissues that assayed PGs and a self- effects have been abandoned. It was observed, for example, evident reduction in PG output after aspirin.
that most of these drugs uncoupled oxidative phosphoryla- The natural result of these experiments was to move the tion and that several salicylates inhibited dehydrogenase focus of Vane’s attention from RCS toward PGs. ‘‘While I enzymes, particularly those dependent on pyridine nucleo- was writing a review paper over the weekend’’, he recalled, tides. Some aminotransferases and decarboxylases were also ‘‘including the results of some of these experiments, a inhibited, as were several key enzymes involved in protein thought occurred to me that perhaps should have been and RNA biosynthesis. All of these inhibitory actions obvious earlier on. In all these experiments (and in those were at some time invoked to explain the therapeutic actions of many other workers), the ‘release’ of PGs must in fact of aspirin. A problem with most of these theories was that the amount to fresh synthesis of PGs. That is, PG output in concentration of the drug required for enzyme inhibition was these experiments, though very low, was still far higher than in excess (sometimes greatly in excess) of the concentration the tissues’ initial content of the hormones. Evidently, then, typically found in the plasma after therapy, and there was the various stimuli, mechanical and chemical, which re- invariably a lack of correlation between the ability of these leased PGs, were in fact ‘turning on’ the synthesis of these drugs to inhibit particular enzymes and their activities as compounds. A logical corollary was that aspirin might well anti-inflammatory agents. Perhaps the most serious imped- iment of all to acceptance of any of the above ideas was that Vane immediately tested this exciting idea on the their proponents could not provide a convincing reason why following Monday morning. In the absence of ram seminal inhibition of any of these enzymes should produce the anti- vesicles, from which the synthetase enzyme was usually inflammatory, analgesic and antipyretic effects of aspirin.
obtained, he used the supernatant of a broken cell ho-mogenate from guinea pig lung, the same kind of prepa-ration in which A detected the generation of PGE2 and PGF2a in 1965.
Aliquots of the supernatant were incubated with arachi- It was against this background of knowledge that the donic acid and different concentrations of aspirin, indo- investigation of aspirin’s action was taken over by prosta- methacin or sodium salicylate. PGF2a generation was J.R. Vane, R.M. Botting / Thrombosis Research 110 (2003) 255–258 estimated by bioassay after 30 min of incubation at 37 jC.
There was a dose-dependent inhibition of PG formation byall three drugs, indomethacin being the most potent and A homogeneous, enzymatically active cyclooxygenase sodium salicylate the least. Three other drugs, morphine (an (COX) or prostaglandin endoperoxide synthase (PGHS) was opiate analgesic), hydrocortisone (a steroidal anti-inflamma- isolated in 1976 This membrane-bound hemoprotein tory) and mepyramine (an antihistamine), had little or no and glycoprotein with a molecular weight of 72 kDa is found in greatest amounts in the endoplasmic reticulum of Vane published the results of these experiments in prostanoid-forming cells It exhibits COX activity that Nature in 1971. Two other reports in the same issue lent both cyclizes arachidonic acid and adds the 15-hydroperoxy support to his findings and extended them considerably.
group to form PGG2. The hydroperoxy group of PGG2 is Both studies originated from the same department, and by reduced to the hydroxy group of PGH2 by a peroxidase that coincidence, one of these stemmed from an entirely inde- uses a wide variety of compounds to provide the requisite pair of electrons. Both COX and hydroperoxidase activities Smith and Willis were investigating the effects of are contained in the same dimeric protein molecule.
aspirin on platelet behaviour. Venous blood samples were Aspirin selectively acetylates the hydroxyl group of one obtained from three colleagues before and 1 h after taking serine residue (Ser 530) located 70 amino acids from the C 600 mg of aspirin orally. Platelets were isolated, washed and terminus of the enzyme Acetylation leads to irrevers- incubated with thrombin and the supernatant was tested for ible COX inhibition; thus, a new enzyme must be synthe- the presence of various substances including PGs. No sized before more prostanoids are produced. When the consistent changes were seen in the release of any of the purified enzyme is acetylated, only the COX, not the hydro- substances except the PGs, which were substantially peroxidase, activity is inhibited. The stoichiometry of this inhibited after aspirin. Indomethacin also blocked PG re- reaction is 1:1, with one acetyl group transferred per enzyme lease when taken orally or when added directly to the monomer of this dimeric protein. At low concentrations, aspirin acetylates PGHS rapidly (within minutes) and selec- The importance of this study lay in its demonstration that tively. At high concentrations, over longer time periods, these drugs were active not only in guinea pig lungs in vitro aspirin will also non-specifically acetylate a variety of but also in humans, in platelets and after oral administration.
proteins and nucleic acids Acetylation of the enzyme In other words, the aspirin effect was not restricted by by aspirin places a bulky substituent on the Ser 530 oxygen species, tissue or route of administration. These conclusions that inhibits binding of arachidonic acid derived support from the final type of experiment reportedin that issue of Nature. Ferreira et al. demonstrated thatthe aspirin-like drugs blocked PG release from the perfused, isolated dog spleen. In the same year, Collier and Flowerreported in Lancet that administration of aspirin By the late 1980s, several reports appeared that the inhibited human seminal PG production.
synthesis of PGHS could be stimulated by growth factors,tumour promoters, interleukin-1 lipopolysaccharideand tumour necrosis factor. Interleukin-1 exerted its effect 3. Correlation of anti-enzyme activity of aspirin with its during the transcriptional rather than during the translational phase of induced synthesis of PGHS Induction ofPGHS gene expression by serum factors occurred after The major importance of these findings was that they approximately 2 h in mouse 3T3 cells, in which PGs are provided a simple explanation of the manner in which essential for cell division. These reports culminated with the aspirin-like drugs exerted their therapeutic actions. When discovery by Dan Simmons of a second, distinct COX the reports were published in 1971, there was already gene which could be induced with mitogens, growth factors, evidence suggesting that PGE1 was an extremely potent tumour promoters and lipopolysaccharide, and the induction pyretic agent in several species and that PGE1 or PGE2 of which could be inhibited with glucocorticoids. This gene mimicked the inflammatory response when injected intra- expresses COX-2 which elaborates PGs, mostly PGE2, dermally. PGs had also been detected in inflammatory during inflammatory reactions in contrast to COX-1, which exudates so there were grounds for speculating that produces PGs involved in physiological processes such as PGs might be responsible, at least in part, for the genesis of protection of the stomach mucosa, platelet aggregation and fever or inflammation and that the aspirin-like drugs might owe their therapeutic activity to their ability to prevent PG There is 60% homology between the amino acid struc- biosynthesis. Certainly, as Flower et al. pointed out, the tures of COX-1 and COX-2 and aspirin binds to Ser 516 in concentrations of these drugs required to inhibit synthesis the active site of COX-2 in the same way as it binds to Ser were within the plasma levels found during therapy, even 530 in the active site of COX-1. However, the active site of when protein binding was taken into account.
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Publikationen aus dem Pathologischen Institut der Universität Würzburg in 1999 Avots, A., Buttmann, M., Chupvilo, S., Escher, C., Smola, U., Bannister, A.J., Rapp, U.R., Kouzarides, T., Serfling, E. CBP/p300 integrates Raf/Rac-signalling pathways in the transcriptional induction of NF-Atc during T cell activation Immunity 10: 515-524 (1999) Chirmule, N., Avots, A., LakshmiTamma, S.M.,


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