Attenuation of alpha-naphthylisothiocyanate (ANIT)-induced biliary fibrosis by depletion of hepatic macrophages in rats.
Biliary fibrosis is a complex process in which macrophages and myofibroblasts may play central roles. We investigated biliary fibrosis lesions induced in the Glisson's sheath in rats by alpha-naphthylisothiocyanate (ANIT) administration under macrophage depletion. Hepatic macrophages were depleted in F344 rats with liposome-encapsulated clodronate (CLD) (10mL/kg body weight, i.v) followed by bile duct injury with ANIT (75mg/kg body weight, i.p) (ANIT+CLD group). Rats received empty-liposomes (Lipo) followed by ANIT, and served as control (ANIT+Lipo group). In both ANIT+Lipo and ANIT+CLD groups, ANIT-induced bile duct injury with inflammatory cell infiltration was seen on days 1-3, and subsequently reparative fibrosis occurred on days 5 and 7. In comparisons between the two groups, macrophages reacting to CD68, CD163, MHC class II and CD204 were less in numbers in ANIT+CLD group; the most sensitive immunophenotype was of CD163-positive. Furthermore, in ANIT+CLD group interstitial mesenchymal cells/myofibroblasts reacting to vimentin, desmin and α-smooth muscle actin were also less in grades and tended to be delayed in appearance. Interestingly, MCP-1, IFN-γ, IL-10, and TGF-β1 mRNAs were significantly increased mainly on day 2 in ANIT+Lipo group, while the levels of these factors were prominently lower in ANIT+CLD group. Collectively, depletion of hepatic macrophages plays roles in attenuating biliary fibrogenesis by production of inflammatory factors. The present results indicated clearly importance of macrophage functions in the pathogenesis of biliary fibrosis.
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano City, Osaka, 598-8531, Japan; Department of Veterinary and Animal Sciences, University of Rajshahi, Motihar, Rajshahi, 6205, Bangladesh.
Hossain M
HM
Golbar
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano City, Osaka, 598-8531, Japan.
Takeshi
T
Izawa
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano City, Osaka, 598-8531, Japan.
Alexandra
A
Bondoc
Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine and Animal Science, University of Peradeniya, 20200, Sri Lanka.
Kavindra K
KK
Wijesundera
Teaching Hospital, Peradeniya, 20200, Sri Lanka.
Anusha H
AH
Tennakoon
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano City, Osaka, 598-8531, Japan.
Mitsuru
M
Kuwamura
Laboratory of Veterinary Pathology, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-58 Rinku-Ourai-Kita, Izumisano City, Osaka, 598-8531, Japan. Electronic address: yamate@vet.osakafu-u.ac.jp.
Jyoji
J
Yamate
D015058:1-Naphthylisothiocyanate / Q000633:toxicity; D000818:Animals; D001649:Bile Duct Diseases / Q000276:immunology / Q000473:pathology*; D004195:Disease Models, Animal; D005355:Fibrosis / Q000276:immunology / Q000473:pathology; D007150:Immunohistochemistry; D061346:Laser Capture Microdissection; D008099:Liver / Q000276:immunology; D008264:Macrophages / Q000276:immunology / Q000473:pathology*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction
D015058:1-Naphthylisothiocyanate
ANIT; Clodronate; Liver; Macrophage depletion; Myofibroblast