Pro‐inflammatory role of transient receptor potential canonical channel 6 in the pathogenesis of chronic rhinosinusitis with nasal polyps

Background The pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP) has not been fully elucidated. This study sought to explore the role and mechanism of transient receptor potential canonical channel 6 (TRPC6) in the pathogenesis of CRSwNP. Methods Immunohistochemistry (IHC) was employed to evaluate TRPC6 immunolabeling. Real‐time polymerase chain reaction (PCR) was conducted to assay TRPC6, stromal interaction molecule 1 (STIM1), and calcium release‐activated calcium channel protein 1 (Orai1) messenger RNA (mRNA) levels in 70 patients with CRSwNP, including eosinophilic CRSwNP (ECRSwNP) or non‐eosinophilic CRSwNP (nECRSwNP), and 28 control subjects. The concentrations of inflammatory mediators, including interleukin (IL)‐1β, IL‐5, and IL‐25, were assayed by enzyme‐linked immunosorbent assay (ELISA). In experiments on human nasal epithelial cell (HNEC) culture and stimulation, the mean fluorescence intensity (MFI) of intracellular Ca2+ was assayed by flow cytometry. Western blotting, real‐time PCR, and ELISA were also conducted to assess the effects and mechanisms of TRPC6 activator 1‐oleoyl‐2‐acetyl‐glycerol (OAG) and TRPC6 inhibitor 1‐[2‐(4‐methoxyphenyl)‐2‐[3‐(4‐methoxyphenyl) propoxy]ethyl‐1H‐imidazole (SKF‐96365) on HNECs. Results Upregulation of TRPC6, STIM1, and Orai1 levels was found in CRSwNP patients, particularly in those with ECRSwNP. TRPC6‐positive cells correlated positively with the numbers of eosinophils and neutrophils, respectively. Moreover, TRPC6 mRNA was positively correlated with STIM1 and Orai1 mRNA levels. The concentrations of inflammatory mediators, including IL‐1β, IL‐5, and IL‐25, were elevated in CRSwNP, especially in ECRSwNP. In cultured HNECs, TRPC6, STIM1, Orai1, Ca2+ MFI levels, and inflammatory mediators were upregulated by lipopolysaccharide (LPS) and OAG but were inhibited by SKF‐96365. Conclusion TRPC6 plays a pro‐inflammatory role in the pathogenesis of CRSwNP via regulating Ca2+ flow. 背景 慢性鼻窦炎伴鼻息肉 (CRSwNP) 的发病机制尚未完全阐明。本研究将对瞬时感受器电位C通道6 (TRPC6) 在CRSwNP发病中的可能作用及机制进行探讨。 方法 免疫组织化学法 (IHC) 检测TRPC6的表达。实时聚合酶链反应 (PCR) 法检测70例CRSwNP患者 (包含嗜酸型CRSwNP (ECRSwNP) 或非嗜酸型CRSwNP (nonECRSwNP) ) 及28例正常对照组的TRPC6、基质相互作用分子1 (STIM1) 、钙释放活化钙通道蛋白1 (Orai1) 的mRNA水平。酶联反应吸附试验 (ELISA) 检测炎性介质白细胞介素‐1β (IL‐1β) 、IL‐5、和IL‐25的浓度。人鼻黏膜上皮细胞 (HNEC) 体外培养试验中, 采用流式细胞技术检测细胞内Ca2+的平均荧光强度 (MFI) 。Western blotting、实时PCR及ELISA技术检测TRPC6活化剂1‐oleoyl‐2‐acetyl‐glycerol (OAG)、TRPC6抑制剂1‐[2‐(4‐methoxyphenyl)‐2‐[3‐(4‐methoxyphenyl) propoxy]ethyl‐1H‐imidazole (SKF‐963