Regulatory effects of the long non-coding RNA RP11-543N12.1 and microRNA-324-3p axis on the neuronal apoptosis induced by the inflammatory reactions of microglia

The present study aimed to examine how the long non-coding RNA (lncRNA) RP11-543N12.1 interacted with microRNA (miR)-324-3p to modify microglials (MIs)-induced neuroblastoma cell apoptosis, which may pose benefits to the treatment of Alzhemier's disease (AD). The cell model of AD was established by treating SH-SY5Y cells with amyloid beta (A beta)(25-35), and MI were acquired using primary cell culture technology. The lncRNAs that were differentially expressed between SH-SY5Y and control cells were screened through a microarray assay and confirmed via polymerase chain reaction. In addition, overexpression of RP11-543N12.1 and miR-324-3p was established by transfection of SH-SY5Y cells with pcDNA3.1(+)-RP11-543N12.1 and miR-324-3p mimics, respectively, while downregulation of RP11-543N12.1 and miR-324-3p was achieved by transfection with RP11-543N12.1-small interfering RNA (siRNA) and miR-324-3p inhibitor, respectively. The interaction between RP11-543N12.1 and miR-324-3p was confirmed with a dual-luciferase reporter gene assay. The results revealed that the expression levels of total and phosphorylated tau in SH-SY5Y cells were significantly elevated following A beta(25-35) treatment (P<0.05), and RP11-543N12.1 was found to be differentially expressed between the control and A beta 25-35-treated cells (P<0.05). Furthermore, the targeted association of RP11-543N12.1 and miR-324-3p was predicted based on miRDB4.0 and PITA databases, and then validated via the dual-luciferase reporter gene assay. SH-SY5Y cells transfected with siRNA or inhibitor, and treated with A beta(25-35) displayed cellular survival and apoptosis that were similar to the normal levels (P<0.05). Finally, co-culture of MI and SH-SY5Y cells transfected with RP11-543N12.1-siRNA/miR-324-3p inhibitor significantly enhanced cell apoptosis (P<0.05). In conclusion, RP11-543N12.1 targeted miR-324-3p to suppress proliferation and promote apoptosis in the AD cell model, suggesting that RP11-543N12.1 and miR-324-3p may be potential biomarkers and therapeutic targets for AD.