Nicotine promotes activation of human pancreatic stellate cells through inducing autophagy via α7nAChR-mediated JAK2/STAT3 signaling pathway

Aim: Pancreatic stellate cells (PSCs) are the main functional cells leading to pancreatic fibrosis. Nicotine is widely considered as an independent risk factor of pancreatic fibrosis, but the mechanism is still unclear. Our study was aimed to explore the effects of nicotine on human pancreatic stellate cells (hPSCs) and involved pathways. Materials and methods: Primary human PSCs were cultured and treated with nicotine (0.1 mu M and 1 mu M). The proliferation, apoptosis, alpha-SMA expression, extracellular matrix metabolism and autophagy of hPSCs were detected by CCK-8 assay, flow cytometry, real-time PCR and Western blotting analysis. The alpha 7nAChR-mediated JAK2/STAT3 signaling pathway was also examined, and an alpha 7nAChR antagonist alpha-bungarotoxin (alpha-BTX) was used to perform inhibition experiments. Key findings: The proliferation, alpha-SMA expression and autophagy of hPSCs were significantly promoted by 1 mu M nicotine. Meanwhile, the apoptosis of hPSCs was significantly reduced. The extracellular matrix metabolism of hPSCs was also regulated by nicotine. Moreover, the alpha 7nAChR-mediated JAK2/STAT3 signaling pathway was activated by nicotine, this pathway and effects of nicotine can be blocked by alpha-BTX. Significance: Our finding suggests that nicotine can promote activation of human pancreatic stellate cells (hPSCs) through inducing autophagy via alpha 7nAChR-mediated JAK2/STAT3 signaling pathway, providing a new insight into the mechanisms by which nicotine affects pancreatic fibrosis.