MicroRNA let-7 and viral infections: focus on mechanisms of action

• Published in: Cellular & molecular biology letters Vol. 27; no. 1; pp. 14 - 47
• Main Authors: Letafati, Arash, Najafi, Sajad, Mottahedi, Mehran, Karimzadeh, Mohammad, Shahini, Ali, Garousi, Setareh, Abbasi-Kolli, Mohammad, Sadri Nahand, Javid, Tamehri Zadeh, Seyed Saeed, Hamblin, Michael R, Rahimian, Neda, Taghizadieh, Mohammad, Mirzaei, Hamed
• Format: Journal Article
• Language: English
• Published: England BioMed Central 14-02-2022; BMC
• Subjects: Antiviral activity; Cytoplasm; Extracellular vesicles; Extracellular Vesicles - metabolism; Humans; Kinases; Let-7; Lipids; Membrane vesicles; MicroRNAs; MicroRNAs - genetics; MicroRNAs - metabolism; miRNA; Post-transcription; Protein transport; Regulatory role; Review; RNA, Messenger - metabolism; Viral infections; Virus Diseases - genetics; Virus Diseases - metabolism; Virus Replication; Viruses; Regulatory role; Let-7; MicroRNAs; Viral infections
• ISSN: 1425-8153; 1689-1392; 1689-1392
• DOI: 10.1186/s11658-022-00317-9

MicroRNAs (miRNAs) are fundamental post-transcriptional modulators of several critical cellular processes, a number of which are involved in host defense mechanisms. In particular, miRNA let-7 functions as an essential regulator of the function and differentiation of both innate and adaptive immune cells. Let-7 is involved in several human diseases, including cancer and viral infections. Several viral infections have found ways to dysregulate the expression of miRNAs. Extracellular vesicles (EV) are membrane-bound lipid structures released from many types of human cells that can transport proteins, lipids, mRNAs, and miRNAs, including let-7. After their release, EVs are taken up by the recipient cells and their contents released into the cytoplasm. Let-7-loaded EVs have been suggested to affect cellular pathways and biological targets in the recipient cells, and can modulate viral replication, the host antiviral response, and the action of cancer-related viruses. In the present review, we summarize the available knowledge concerning the expression of let-7 family members, functions, target genes, and mechanistic involvement in viral pathogenesis and host defense. This may provide insight into the development of new therapeutic strategies to manage viral infections.