title: Inhibition of Kupffer cell-mediated early proinflammatory response with carbon monoxide in transplant-induced hepatic ischemia/reperfusion injury in rats.
abstract: Proinflammatory responses play critical roles in hepatic ischemia/reperfusion (I/R) injury associating with liver transplantation (LTx), and carbon monoxide (CO) can effectively down-regulate them. Using wild-type (WT) to enhanced green fluorescent protein (EGFP)-transgenic rat LTx with 18-hour cold preservation in University of Wisconsin solution, this study analyzed the relative contribution of donor and host cells during early posttransplantation period and elucidated the mechanism of hepatic protection by CO. CO inhibited hepatic I/R injury and reduced peak alanine aminotransferase levels at 24 hours and hepatic necrosis at 48 hours. Abundant EGFP(+) host cells were found in untreated WT liver grafts at 1 hour and included nucleated CD45(+) leukocytes (myeloid, T, B, and natural killer cells) and EGFP(+) platelet-like depositions in the sinusoids. However, reverse transcription polymerase chain reaction (RT-PCR) analysis of isolated graft nonparenchymal cells (NPCs) revealed that I/R injury-induced proinflammatory mediators [for example, tumor necrosis factor alpha (TNF-alpha), interleukin-6 (IL-6), and inducible nitric oxide synthase (iNOS)] were not up-regulated in purified CD45(+) cells of donor or host origin. Instead, TNF-alpha and IL-6 messenger RNA (mRNA) elevation was exclusively seen in isolated CD68(+) cells, whereas iNOS mRNA up-regulation was seen in hepatocytes. Nearly all CD68(+) cells at 1 hour after LTx were EGFP(-) donor Kupffer cells, and CO efficiently inhibited TNF-alpha and IL-6 up-regulation in the CD68(+) Kupffer cell fraction. When graft Kupffer cells were inactivated with gadolinium chloride, activation of inflammatory mediators in liver grafts was significantly inhibited. Furthermore, in vitro rat primary Kupffer cell culture also showed significant down-regulation of lipopolysaccharide (LPS)-induced inflammatory responses by CO.
  
  
  CONCLUSIONS
  These results indicate that CO ameliorates hepatic I/R injury by down-regulating graft Kupffer cells in early postreperfusion period. The study also suggests that different cell populations play diverse roles by up-regulating distinctive sets of mediators in the acute phase of hepatic I/R injury.
authors.affiliation: Department of Surgery, Thomas E Starzl Transplantation Institute, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA.
authors.forename: Koji
authors.initials: K
authors.lastname: Tomiyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ikeda
authors.forename: Shinya
authors.initials: S
authors.lastname: Ueki
authors.forename: Atsunori
authors.initials: A
authors.lastname: Nakao
authors.forename: Donna B
authors.initials: DB
authors.lastname: Stolz
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Koike
authors.forename: Amin
authors.initials: A
authors.lastname: Afrazi
authors.forename: Chandrashekhar
authors.initials: C
authors.lastname: Gandhi
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tokita
authors.forename: David A
authors.initials: DA
authors.lastname: Geller
authors.forename: Noriko
authors.initials: N
authors.lastname: Murase
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002248:Carbon Monoxide / Q000627:therapeutic use*; D005434:Flow Cytometry; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000235:genetics; D007249:Inflammation / Q000473:pathology / Q000517:prevention & control*; D015847:Interleukin-4 / Q000378:metabolism; D007728:Kupffer Cells / Q000473:pathology*; D008099:Liver / Q000473:pathology / Q000648:ultrastructure; D016031:Liver Transplantation / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015427:Reperfusion Injury / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D014409:Tumor Necrosis Factor-alpha; D049452:Green Fluorescent Proteins; D015847:Interleukin-4; D002248:Carbon Monoxide