Reciprocal effects of micro-RNA-122 on expression of heme oxygenase-1 and hepatitis C virus genes in human hepatocytes.
OBJECTIVE
Heme oxygenase-1 (HO-1) is an antioxidant defense and key cytoprotective enzyme, which is repressed by Bach1. Micro-RNA-122 (miR-122) is specifically expressed and highly abundant in human liver and required for replication of hepatitis C virus (HCV) RNA. This study was to assess whether a specific miR-122 antagomir down-regulates HCV protein replication and up-regulates HO-1.


METHODS
We transfected antagomir of miR-122, 2'-O-methyl-mimic miR-122, or nonspecific control antagomir, into wild-type (WT) Huh-7 cells or Huh-7 stably replicating HCV subgenomic protein core through nonstructural protein 3 of HCV (NS3) (CNS3 replicon cells) or NS3-5B (9-13 replicon cells).


RESULTS
Antagomir of miR-122 reduced the abundance of HCV RNA by 64% in CNS3 and by 84% in 9-13 cells. Transfection with 2'-O-methlyl-mimic miR-122 increased HCV levels up to 2.5-fold. Antagomir of miR-122 also decreased Bach1 and increased HO-1 mRNA levels in CNS3, 9-13, and WT Huh-7 cells. Increasing HO-1 by silencing Bach1 with 50 nmol/L Bach1-short interfering RNA or by treatment with 5 mumol/L cobalt protoporphyrin or heme (known inducers of HO-1) decreased HCV RNA and protein by 50% in HCV replicon cells.


CONCLUSIONS
Down-regulation of HCV replication using an antagomir targeted to miR-122 is effective, specific, and selective. Increasing HO-1, by silencing the Bach1 gene or by treatment with cobalt protoporphyrin or heme, decreases HCV replication. Thus, miR-122 plays an important role in the regulation of HCV replication and HO-1/Bach1 expression in hepatocytes. Down-regulation of miR-122 and up-regulation of HO-1 may be new strategies for anti-HCV intervention and cytoprotection.
Shan
Ying
Y
Department of Medicine, University of Connecticut Health Center, Farmington, Connecticut, USA. ying.shan@umassmed.edu
Zheng
Jianyu
J
Lambrecht
Richard W
RW
Bonkovsky
Herbert L
HL
D000070416:Antagomirs; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004790:Enzyme Induction; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism; D015967:Gene Expression Regulation, Viral / Q000187:drug effects; D006418:Heme / Q000494:pharmacology; D051547:Heme Oxygenase-1 / Q000096:biosynthesis / Q000378:metabolism*; D016174:Hepacivirus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000821:virology; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D009841:Oligonucleotides / Q000378:metabolism; D011524:Protoporphyrins / Q000494:pharmacology; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D012367:RNA, Viral / Q000378:metabolism; D014162:Transfection; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000070416:Antagomirs; D050976:Basic-Leucine Zipper Transcription Factors; D051856:Fanconi Anemia Complementation Group Proteins; D006418:Heme; D051547:Heme Oxygenase-1; D035683:MicroRNAs; D009841:Oligonucleotides; D011524:Protoporphyrins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012367:RNA, Viral; D017361:Viral Nonstructural Proteins; C102108:BACH1 protein, human; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C520440:antagomir-122; C007095:cobaltiprotoporphyrin; C496541:HMOX1 protein, human