tailieunhanh - Báo cáo y học: " Targeting viral infection by microRNA inhibition"

Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Targeting viral infection by microRNA inhibition. | Roberts and Jopling Genome Biology 2010 11 201 http 2010 11 1 201 w Genome Biology MINIREVIEW L__ Targeting viral infection by mieroRNA inhibition Ashley PE Roberts and Catherine L Jopling Abstract An inhibitor of microRNA-122 reduces viral load in chimpanzees that are chronically infected with hepatitis C virus suggesting that such an approach might have therapeutic potential in humans. Hepatitis C virus and microRNAs MicroRNAs miRNAs are gaining an increasingly prominent role as regulators of numerous cellular processes including virus-host interactions. They are short 21-23 nucleotide non-coding regulatory RNAs that influence gene expression at a post-transcriptional level 1 . miRNAs are encoded as part of long nuclear transcripts which are processed in the nucleus by Drosha then exported to the cytoplasm and further processed by Dicer. The resulting mature miRNA strand is loaded into the RNA-induced silencing complex RISC which acts as the effector of miRNA activity 1 . In animals target specificity is usually determined by a 6-8mer seed at the 5 end of the miRNA. Typically miRNAs bind sites in the 3 untranslated regions UTRs of mRNAs that have perfect complementarity to the seed but imperfect complementarity to the remainder of the miRNA. The precise mechanism of miRNA-mediated repression is not fully defined both translational repression and degradation of miRNA-RISC-bound mRNAs have been observed in different studies 1 . Several viruses interact with the miRNA pathway. Certain viruses produce their own miRNAs which regulate viral or cellular targets whereas some viruses are regulated directly or indirectly by cellular miRNAs 2 . One important virus that has a requirement for a specific miRNA is hepatitis C virus HCV . HCV infects the liver and is a major global health concern with an estimated 170 million people infected worldwide 3 . In the majority of cases acute infection with HCV progresses to chronic infection although .