S-adenosylmethionine and Pneumocystis.
Pneumocystis is a parasitic fungus causing pneumonia in immunosuppressed mammals and S-adenosylmethionine a key intermediary metabolite for all cells. Other than a species of Rickettsia bacteria and an aberrant strain of the protozoan Amoeba proteus, Pneumocystis is the only cell known unable to synthesize AdoMet; it must extract this key compound from its host. This was discovered using a culture system and confirmed by observing depletion of AdoMet in the plasma of infected animals. Depletion also occurs in patients with Pneumocystis pneumonia (PcP), a phenomenon suggested as a basis for a method for diagnosis and evaluation of response to therapy. Preliminary data indicate that deliberate reduction of host lung AdoMet by nicotine treatment is therapeutic in the rat model of Pneumocystis pneumonia.
Merali
Salim
S
Department of Medical and Molecular Parasitology, New York University School of Medicine, 341 East 25th Street, New York, NY, USA. merals01@med.nyu.edu
Clarkson
Allen Boykin
AB
D000818:Animals; D006801:Humans; D008716:Methionine Adenosyltransferase / Q000235:genetics; D009538:Nicotine / Q000627:therapeutic use; D011010:Pneumocystis / Q000254:growth & development / Q000378:metabolism*; D011020:Pneumonia, Pneumocystis / Q000097:blood / Q000188:drug therapy* / Q000378:metabolism; D051381:Rats; D012436:S-Adenosylmethionine / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000502:physiology
D009538:Nicotine; D012436:S-Adenosylmethionine; D008716:Methionine Adenosyltransferase