Liu Shao-Cheng, Lu Hsuan-Hsuan, Fan Hueng-Chuen, Wang Hsing-Won, Chen Hang-Kang, Lee Fei-Peng, Yu Chong-Jen, Chu Yueng-Hsiang
Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University Department of Internal Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University Department of Pediatrics, Tungs' Taichung Metro Harbor Hospital Department of Otolaryngology-Head and Neck Surgery, Shuang Ho Hospital, Taipei, Taiwan, Republic of China.
Medicine (Baltimore). 2017 Aug;96(31):e7640. doi: 10.1097/MD.0000000000007640.
It has been proposed that the transient receptor potential (TRP) channel Melastatin 8 (TRPM8) is a cold-sensing TRP channel. However, its presence and its role in the nasal cavity have not yet been fully studied.
Immunohistology was used to study TRPM8 receptors in both the nasal mucosa tissue and the primary cultures of human nasal cells. Cells from primary cultures were immunostained with antibodies to TRPM8, mucin, cytokeratin (CK)-14, CK-18, and vimentin. Western blotting and real-time polymerase chain reaction (PCR) were used to determine the physiological role of TRPM8 in mucus production in the nasal cavity, with and without its agonist and antagonist.
The TRPM8 is clearly present in the epithelium, mucous glands, and vessels. No obvious TRPM8-immunoreactive cells were detected in the connective tissue. Immunostaining of cytospin preparations showed that epithelial cells test positive for CK-14, CK-18, TRPM8, and mucin 5AC (MUC5AC). Fibroblastic cells are stained negative for TRPM8. Secreted mucins in the cultured supernatant are detected after exposure to menthol and moderate cooling to 24°C. Both induce a statistically significant increase in the level of MUC5AC mRNA and mucin production. BCTC, a TRPM8 antagonist, has a statistically significant inhibitory effect on MUC5AC mRNA expression and MUC5AC protein production that is induced by menthol and moderate cooling to 24°C.
The study demonstrates that TRPM8 is present in the nasal epithelium. When it is activated by moderate cooling to 24°C or menthol, TRPM8 induces the secretion of mucin. This study shows that TRPM8 channels are important regulators of mucin production. Therefore, TRPM8 antagonists could be used to treat refractory rhinitis.
有人提出瞬时受体电位（TRP）通道褪黑素8（TRPM8）是一种冷敏TRP通道。然而，其在鼻腔中的存在及其作用尚未得到充分研究。
采用免疫组织学方法研究鼻黏膜组织和人鼻细胞原代培养物中的TRPM8受体。用抗TRPM8、粘蛋白、细胞角蛋白（CK）-14、CK-18和波形蛋白的抗体对原代培养的细胞进行免疫染色。使用蛋白质免疫印迹法和实时聚合酶链反应（PCR）来确定TRPM8在有无激动剂和拮抗剂的情况下对鼻腔黏液分泌的生理作用。
TRPM8明显存在于上皮、黏液腺和血管中。在结缔组织中未检测到明显的TRPM8免疫反应性细胞。细胞涂片制剂的免疫染色显示，上皮细胞对CK-14、CK-18、TRPM8和粘蛋白5AC（MUC5AC）呈阳性。成纤维细胞对TRPM8染色呈阴性。暴露于薄荷醇并适度冷却至24°C后，可检测到培养上清液中分泌的粘蛋白。两者均能使MUC5AC mRNA水平和粘蛋白分泌量在统计学上显著增加。TRPM8拮抗剂BCTC对薄荷醇和适度冷却至24°C诱导的MUC5AC mRNA表达和MUC5AC蛋白分泌具有统计学上的显著抑制作用。
该研究表明TRPM8存在于鼻上皮中。当通过适度冷却至24°C或薄荷醇激活时，TRPM8会诱导粘蛋白分泌。这项研究表明TRPM8通道是粘蛋白分泌的重要调节因子。因此，TRPM8拮抗剂可用于治疗难治性鼻炎。
