MicroRNA 29b (miR-29b)

MicroRNA 29b (miR-29b) is a small, endogenous non-coding RNA that functions as a master regulator of gene expression by binding to the 3'-untranslated regions (UTRs) of target messenger RNAs (mRNAs) (NIH.gov). It is a key member of the miR-29 family and is primarily recognized for its potent anti-fibrotic and tumor-suppressive activities across various tissues (Physiology.org, NIH.gov). miR-29b directly targets and suppresses the expression of numerous genes involved in extracellular matrix (ECM) synthesis, including multiple types of collagen (COL1A1, COL3A1), as well as anti-apoptotic factors like MCL1 and epigenetic regulators like DNA methyltransferases (DNMT3A/B) (NIH.gov, Dove Press). In pathological conditions such as systemic sclerosis, cardiac fibrosis, and several types of cancer (e.g., acute myeloid leukemia and multiple myeloma), miR-29b levels are frequently downregulated, contributing to disease progression (Physiology.org, Taylor & Francis). Therapeutic interventions, such as the miR-29b mimic Remlarsen (MRG-201), aim to restore miR-29b activity to inhibit fibrosis and induce apoptosis in malignant cells (ResearchGate). However, the broad regulatory network of miR-29b presents challenges, including potential off-target effects and the need for sophisticated delivery systems to ensure tissue-specific action (CNR.it, AACR Journals).

Other names

miR-29b-3phsa-mir-29bMicroRNA 29b-1MicroRNA 29b-2hsa-miR-29b-3p

miR-29b mimics (e.g., Remlarsen) function by supplementing endogenous levels of the microRNA, which then binds to the 3'-untranslated region (UTR) of target mRNAs such as collagen genes (COL1A1, COL3A1), anti-apoptotic genes (MCL1), and DNA methyltransferases (DNMT3A/B). This binding leads to mRNA degradation or translational inhibition, thereby reducing the expression of pro-fibrotic and anti-apoptotic proteins (NIH.gov, Dove Press, ResearchGate).