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A1309 - Mechanism of Periostin Production in Human Bronchial Smooth Muscle Cells
Author Block: K. Makita1, Y. Mikami1, H. Matsuzaki1, N. Miyashita1, H. Takeshima1, S. Noguchi1, M. Horie1, H. Urushiyama1, M. Iikura2, M. Hojo3, Y. Yamauchi1, T. Nagase1; 1Department of Respiratory Medicine, The University of Tokyo, Tokyo, Japan, 2National Center for Global Health and Medicine, Tokyo, Japan, 3Department of Respiratory Medicine, NTT Medical Center, Tokyo, Japan.
Background: Asthma is a chronic airway inflammatory disease characterized by airway remodeling, in which bronchial smooth muscle (BSM) cells play important roles. Periostin, a biomarker that reflects Th2-driven inflammatory diseases such as asthma, may play important roles in the asthmatic airway. Although periostin is mainly produced in airway epithelial cells and fibroblasts after interleukin (IL)-13 stimulation, whether BSM cells produce periostin remains unclear. Therefore, we investigated periostin production in BSM cells and its mechanisms.Methods: Human BSM cells were cultured, and the effect of IL-13 stimulation on periostin production was evaluated using quantitative polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA). Gene expression profile induced by IL-13 in BSM cells were assessed by RNA sequence to investigate the intracellular signaling pathway of periostin production. We evaluated the phosphorylation of signal transducer and activator of transcription factor 6 (STAT6), extracellular signal-regulated kinase (ERK) 1/2, and Akt after IL-13 stimulation. Furthermore, using ELISA, we evaluated the influence of several phosphorylation inhibitors on periostin production.Results: Periostin mRNA expression increased in a dose- and time-dependent manner after IL-13 stimulation. Periostin production was detected in the culture supernatant from BSM cells and periostin concentration increased to 288 ± 19 ng/ml at 24 h and to 808 ± 46 ng/ml at 48 h in a time dependent manner. The results of RNA sequence suggested that the ERK 1/2 pathway may be involved in periostin production. IL-13 stimulation induced phosphorylation of STAT6, ERK 1/2, and Akt. IL-13-induced periostin production was attenuated by inhibiting STAT6 phosphorylation and was strongly suppressed by inhibiting mitogen-activated protein kinase kinase (MEK) 1/2 phosphorylation or phosphatidylinositol 3-kinase (PI3K) phosphorylation. Conclusions: Our study demonstrates that BSM cells produce and secrete periostin after IL-13 stimulation through the JAK/STAT6, ERK1/2, and PI3K/Akt pathways. This suggests that BSM cells are important cell sources of periostin production in Th2-derived inflammatory diseases. Understanding the mechanism of periostin production in BSM cells might help clarify asthma pathogenesis and discover new therapeutic targets for managing asthma.