Differential effects of calcineurin inhibitors, tacrolimus and cyclosporin a, on interferon-induced antiviral protein in human hepatocyte cells.
The premise of our study is that selective inhibition of interferon (IFN) by calcineurin inhibitors contribute to the increased severity of hepatitis C virus (HCV) posttransplantation. Therefore, we examined the influence of calcineurin inhibitors in the human hepatocyte cell line on IFN-alpha-induced phosphorylation of Janus kinase (Jak) and signal transducers and activators of transcription (STAT), nuclear translocation of IFN-stimulated gene factor 3 (ISGF-3), IFN-stimulated regulatory element (ISRE)-contained promoter activity, and the expressions of antiviral proteins. Tacrolimus (Tac), but not cyclosporin A (CyA), had an inhibitory effect on IFN-alpha-induced double-stranded ribonucleic acid (RNA)-dependent protein kinase (PKR) in a dose-dependent manner. STAT-1 also acted in a similar fashion to PKR. IFN-alpha combined with Tac attenuated the ISRE-containing promoter gene activity as compared with IFN-alpha alone. In contrast, its expression in pretreated CyA was slightly attenuated. In pretreated Tac, but not CyA, the levels of IFN-alpha-induced tyrosine phosphorylated STAT-1 and -2 were clearly lower than those induced by IFN-alpha alone. Tac and CyA did not decrease the IFN-alpha-induced JAK-1 phosphorylation. The nuclear translocation rate of tyrosine phosphorylated STAT-1 was inhibited by pretreatment of both Tac and CyA by western blotting and immunohistochemistry. In an HCV replicon system, pretreated Tac diminished the replication inhibitory effect of IFN-alpha. In this study, we show that calcineurin inhibitors, especially Tac, are the negative regulators of IFN signaling in the hepatocyte; the greatest cause of such inhibition is the phosphorylation disturbance of STAT-1, next to inhibition of the nuclear translocation of STAT-1. In conclusion, disturbance of tyrosine phosphorylation of STAT-1 resulted in diminished ISRE-containing promoter activity and a decline in antiviral protein expression. Moreover, the replication of HCV was activated. This phenomenon is detrimental to IFN therapy after liver transplantation, and the selection of calcineurin inhibitors may warrant further discussion depending on the transplant situation.
Hirano
Kumi
K
Department of Clinical Pharmaceutics, Nagasaki University, Nagasaki, Japan.
Ichikawa
Tatsuki
T
Nakao
Kazuhiko
K
Matsumoto
Azusa
A
Miyaaki
Hisamitsu
H
Shibata
Hidetaka
H
Eguchi
Susumu
S
Takatsuki
Mitsuhisa
M
Ikeda
Masanori
M
Yamasaki
Hironori
H
Kato
Nobuyuki
N
Kanematsu
Takashi
T
Ishii
Nobuko
N
Eguchi
Katsumi
K
D000998:Antiviral Agents / Q000494:pharmacology*; D065095:Calcineurin Inhibitors; D002460:Cell Line; D045744:Cell Line, Tumor; D016572:Cyclosporine / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D016174:Hepacivirus / Q000187:drug effects* / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit / Q000235:genetics / Q000378:metabolism; D016898:Interferon-alpha / Q000494:pharmacology*; D053612:Janus Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011994:Recombinant Proteins; D050794:STAT1 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016559:Tacrolimus / Q000494:pharmacology*; D014779:Virus Replication / Q000187:drug effects
D000998:Antiviral Agents; D065095:Calcineurin Inhibitors; C494227:IRF9 protein, human; D000077190:Interferon alpha-2; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit; D016898:Interferon-alpha; D011994:Recombinant Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D016572:Cyclosporine; D053612:Janus Kinases; D016559:Tacrolimus