title: Low-molecular-weight polyethylene glycol improves survival in experimental sepsis.
abstract: OBJECTIVE
  For several chronic inflammatory disease states, therapy is enhanced by improving the pharmacokinetic properties of anti-inflammatory drugs through conjugation with polyethylene glycol. We hypothesized that part of the beneficial action of PEGylated drugs may be derived from the anti-inflammatory properties of polyethylene glycol (PEG) itself.
  
  
  METHODS
  Randomized, double-blinded, controlled ex vivo and in vivo laboratory studies.
  
  
  METHODS
  University research laboratories.
  
  
  METHODS
  Human neutrophils and mononuclear cells, macrophage cell line, and adult rats and mice.
  
  
  METHODS
  The effect of PEG (either low-molecular-weight [200-400] or high-molecular-weight [>4000]) was assessed on survival after systemic inflammation induced by lipopolysaccharide or zymosan. The effects of PEG on zymosan, lipopolysaccharide, or streptolysin-induced inflammatory and bioenergetic responses of immune cells were also assessed.
  
  
  RESULTS
  Low-molecular-weight PEG reduced inflammatory cytokine expression, pyrexia, and mortality by >50% in both lipopolysaccharide and zymosan models of sepsis. Low-molecular-weight PEG reduced cytokine expression both in vivo and in vitro, and attenuated activation of human neutrophils in response to lipopolysaccharide or zymosan. By contrast, high-molecular-weight PEG conferred less significant survival effects after lipopolysaccharide and zymosan, and it did not exhibit such profound anti-inflammatory effects. Low-molecular-weight PEG attenuated lipopolysaccharide-induced activation of pro-apoptotic pathways (lysophosphatidic acid receptor and caspase-domain signaling) in the livers of endotoxemic rats. Streptolysin-induced necrosis of human neutrophils was reduced by low-molecular-weight PEG, indicating a mechanism that involves coating and/or stabilizing the cellular membrane. Low-molecular-weight PEG preserved human neutrophil responses to septic serum and bioenergetic function in macrophages and neutrophils.
  
  
  CONCLUSIONS
  PEG is a commonly used, safe, nonimmunogenic molecule possessing hitherto unappreciated anti-inflammatory properties. Low-molecular-weight PEG may potentially play a role in the therapy of systemic inflammation and sepsis.
authors.affiliation: Centre for Anaesthesia, Critical Care and Pain Management, University College London, London, UK. g.ackland@ucl.ac.uk
authors.forename: Gareth L
authors.initials: GL
authors.lastname: Ackland
authors.forename: Ana
authors.initials: A
authors.lastname: Gutierrez Del Arroyo
authors.forename: Song T
authors.initials: ST
authors.lastname: Yao
authors.forename: Robert C
authors.initials: RC
authors.lastname: Stephens
authors.forename: Alexander
authors.initials: A
authors.lastname: Dyson
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Klein
authors.forename: Mervyn
authors.initials: M
authors.lastname: Singer
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Gourine
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D016207:Cytokines / Q000096:biosynthesis; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007249:Inflammation / Q000188:drug therapy; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009504:Neutrophils / Q000187:drug effects; D011092:Polyethylene Glycols / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017208:Rats, Wistar; D018805:Sepsis / Q000188:drug therapy*; D013318:Stroke Volume / Q000187:drug effects
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D011092:Polyethylene Glycols