Activation of JAK-STAT pathway is required for platelet-derived growth factor-induced proliferation of pancreatic stellate cells

摘要

AIM: To clarify the role of Janus kinase-signal transducersand activators of transcription (JAK-STAT) pathway in platelet-derived growth factor (PDGF) induced proliferation in activated pancreatic stellate cells (PSCs).METHODS: PSCs were isolated from rat pancreas tissue, and used in their culture-activated, myofibroblast-like phenotype. STAT-specific binding activity was assessed by electrophoretic mobility shift assay. Activation of Src, JAK2,STAT1, STAT3, and ERK was determined by Western blotting using anti-phosphospecific antibodies. Cell proliferation was assessed by measuring the incorporation of 5-bromo-2′deoxyuridine.RESULTS: PDGF-BB induced STAT-specific binding activity, and activation of Src, JAK2, STAT1, STAT3, and ERK. Ethanol and acetaldehyde at clinically relevant concentrations decreased basal activation of JAK2 and STAT3. PDGFinduced activation of STAT1 and STAT3 was inhibited bya Src inhibitor PP1 and a JAK2 inhibitor AG490, whereasPDGF-induced activation of ERK was inhibited by PP1, and not by AG490. PDGF-induced proliferation was inhibited by PP1 and AG490 as well as by STAT3 antisense oligonucleotide.CONCLUSION: PDGF-BB activated JAK2-STAT pathwayvia Src-dependent mechanism. Activation of JAK2-STAT3pathway, in addition to ERK, may play a role in PDGF-induced proliferation of PSCs.