MicroRNA let-7b-5p (let-7b-5p)

MicroRNA let-7b-5p is a highly conserved non-coding RNA molecule that belongs to the let-7 family, which is essential for regulating gene expression post-transcriptionally (NCBI Gene ID: 406884). It primarily functions by binding to the 3' untranslated regions (UTRs) of target mRNAs, leading to their degradation or the inhibition of their translation into proteins (Gilles and Slack, 2018). In inflammatory contexts, let-7b-5p acts as a critical modulator; it can suppress pro-inflammatory cytokines like IL-6 and TNF-alpha, but it also serves as an endogenous ligand for Toll-like receptor 7 (TLR7), particularly in the central nervous system (Lehmann et al., 2012). This interaction with TLR7 can trigger neuroinflammatory cascades and contribute to neuronal apoptosis, linking it to neurodegenerative diseases such as Alzheimer's disease (PubMed: 22643881). Furthermore, let-7b-5p is frequently downregulated in various cancers, where it acts as a tumor suppressor by targeting oncogenes like HMGA2 and RAS (PubMed: 29338757). Therapeutic development focuses on miRNA mimics to restore its function in cancer or antagomirs to inhibit its pathological pro-inflammatory signaling in chronic diseases.

Other names

hsa-let-7b-5pMIR7Blet-7bMicroRNA let-7b

Post-transcriptional gene silencing via mRNA degradation or translational inhibition; also acts as an agonist for Toll-like receptor 7 (TLR7) (Lehmann et al., 2012; Gilles and Slack, 2018).