Fig. 5

The modulation of miR-141 on SIRT1/NF-κB signaling pathway. a KEGG analysis demonstrating NF-κB pathway enriched in IDD. b Cultured primary human NP cells were transfected with miR-141 mimics, miR-141 inhibitor, their negative control, control siRNA, or SIRT1 siRNA for 72 h and then the levels of SIRT1, P65, p-P65, TNF-α, IL-1β, IL-6, Col II, aggrecan, MMP13, and ADAMTS-5 were measured by western blotting. c The rescue experiments was established in cultured primary human NP cells to validate the relationship between miR-141 and SIRT1. Inhibition of Col II and Aggrecan expression levels by miR-141 mimics was rescued by restoration of SIRT1 expression. In comparison, inhibition of MMP13 and ADAMT5 expression levels by SIRT1 overexpression was rescued by miR-141 mimics. d Upregulation of Col II and Aggrecan expression levels by miR-141 inhibitor was abolished by silencing of SIRT1 expression. In comparison, upregulation of MMP13 and ADAMT5 expression levels by silencing of SIRT1 was abolished by miR-141 inhibitor. e Schematic representation of mechanisms by which miR-141mediates IDD development. On the basis of findings described in the manuscript, miR-141 downregulates SIRT1 level in NP cells, leading to increased P65 and p-P65. This transcription factor, in turn, leads to increased levels of multiple pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), decreased Col II and aggrecan levels, and increased levels of MMP13 and ADAMTS-5, which induces an imbalance between anabolic and catabolic activities of NP cells. These adverse factors initiate or accelerate IDD