title: Role of toll-like receptor 4 in mediating multiorgan dysfunction in mice with acetaminophen induced acute liver failure.
abstract: Strategies for the prevention of multiorgan dysfunction (MOD) in acetaminophen (APAP)-induced acute liver failure (ALF) are an unmet need. Our study tested the hypothesis that sterile inflammation induced by APAP in a mouse model would activate toll-like receptor 4 (TLR4) in the liver and extrahepatic organs and lead to the progression of ALF and MOD and that the administration of the novel TLR4 antagonist STM28 (a peptide formed of 17 amino-acids) would prevent liver injury and associated MOD. ALF and, subsequently, MOD were induced in TLR4-knockout (KO) mice (B6.B10ScN-Tlr4 (lpsdel) /JthJ) and wild-type (WT) mice (C57BL/6) with APAP (500 mg/kg). A second set of experiments was conducted to evaluate the effects of a pretreatment with a novel TLR4 antagonist, STM28, on APAP-induced MOD in CD1 mice. Animals were sacrificed at the coma stage, and plasma, peripheral blood cells, liver, kidneys, and brain were collected. Biochemistry values and cytokines were measured. Liver and kidneys were studied histologically and were stained for TLR4 and activated Kupffer cells, and the expression of nuclear factor kappa B-p65 was quantified with western blotting. Brain water was measured in the frontal cortex. After APAP administration, TLR4-KO (NFkBp65) mice were relatively protected from liver necrosis and end-organ dysfunction and had significantly better survival than WT controls (P < 0.01). STM28 attenuated liver injury and necrosis, reduced creatinine levels, and delayed the time to a coma significantly. The increases in cytokines in the plasma and liver, including TLR4 expression and the activation of Kupffer cells, after APAP administration were reduced significantly in the STM28-treated animals. The increased number of circulating myeloid cells was reduced significantly after STM28 treatment. In conclusion, these data provide evidence for an important role of the TLR4 antagonist in the prevention of the progression of APAP-induced ALF and MOD.
authors.affiliation: Liver Failure Group, UCL Institute for Liver and Digestive Health, Royal Free Hospital, London, United Kingdom.
authors.forename: Naina
authors.initials: N
authors.lastname: Shah
authors.forename: Montserrat
authors.initials: M
authors.lastname: Montes de Oca
authors.forename: Maria
authors.initials: M
authors.lastname: Jover-Cobos
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Tanamoto
authors.forename: Masashi
authors.initials: M
authors.lastname: Muroi
authors.forename: Kei-Ichi
authors.initials: K
authors.lastname: Sugiyama
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Davies
authors.forename: Rajeshwar P
authors.initials: RP
authors.lastname: Mookerjee
authors.forename: Dipok Kumar
authors.initials: DK
authors.lastname: Dhar
authors.forename: Rajiv
authors.initials: R
authors.lastname: Jalan
mesh_terms: D000082:Acetaminophen / Q000009:adverse effects*; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D001921:Brain / Q000378:metabolism / Q000473:pathology; D016207:Cytokines / Q000378:metabolism; D018450:Disease Progression; D007249:Inflammation; D008070:Lipopolysaccharides / Q000737:chemistry; D017114:Liver Failure, Acute / Q000139:chemically induced*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009102:Multiple Organ Failure / Q000503:physiopathology*; D010455:Peptides / Q000737:chemistry; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000502:physiology*; D000097382:CD68 Molecule
chemical_list: D000082:Acetaminophen; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D016207:Cytokines; D008070:Lipopolysaccharides; D010455:Peptides; D051197:Toll-Like Receptor 4; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C533008:STM28; C493487:Tlr4 protein, mouse