STX12 lncRNA/miR-148a/SMAD5 participate in the regulation of pancreatic stellate cell activation through a mechanism involving competing endogenous RNA.

BACKGROUND: With the deepening of research, the roles of LncRNAs play in the fibrotic process have attracted great attention. At the early stage of pancreatic fibrogenesis, to effectively regulate pancreatic stellate cells (PSCs) activation is crucial for the treatment of chronic pancreatic fibrosis.

METHODS: Microarray data on chronic pancreatitis were retrieved from the Gene Expression Omnibus (GEO) repository and analyzed using bioinformatic methods. A diagram of the lncRNA-miRNA-mRNA ceRNA network was constructed. In addition, activated rat PSCs were transfected with a small interfering RNA (siRNA) targeting the syntaxin-12 (STX12) lncRNA. Then, the expression of STX12, miR-148a and miR-130b were examined by RT-PCR. The expression of the interleukin 6 signal transducer (IL6ST), SMAD family member 5 (SMAD5) and alpha smooth muscle actin (α-SMA) proteins were examined by western blot. The expression of α-SMA were examined by immunofluorescence staining.

RESULTS: Based on the results of bioinformatic analysis, a lncRNA-miRNA-mRNA network was established. A number of putative ceRNA pairs regulating the activation of PSCs were identified, including STX12 lncRNA/(miR-148a or miR-130b)/(SMAD5 or IL6ST). The expression of STX12 was downregulated (relative expression level: 0.23 ± 0.01, P < 0.01), while the expression of miR-148a was significantly elevated (relative expression level: 1.54 ± 0.02, p < 0.01), and the expression of miR-130b was markedly reduced (relative expression level: 0.69 ± 0.02, p < 0.01). The expression of SMAD5 was decreased (relative expression level: 0.70 ± 0.04, p < 0.05), whereas the expression of IL6ST displayed no significant change (p = 0.24). Additionally, the expression of α-SMA was dramatically reduced (relative expression level: 0.32 ± 0.04, p < 0.01), and immunofluorescence analysis confirmed that α-SMA expression was decreased in cells.

CONCLUSION: During the PSCs activation in chronic pancreatitis, the existence of ceRNA interactions in pancreatic fibrosis has been demonstrated. Regulation of the STX12/miR-148a/SMAD5 axis may serve as a new gene therapy strategy for the treatment of chronic pancreatitis and reversal of pancreatic fibrosis.