miR-21调控PTEN参与破坏慢性鼻-鼻窦炎伴鼻息肉黏膜上皮屏障的研究

The disruption of nasal epithelial barrier function is an important feature and plays a pivotal role in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). In our previous study, we found that the expression level of miR-21 was significantly higher in nasal mucosa from CRSwNP patients than healthy control. The adverse cytokines of epithelial barrier such as IL-13 and TGF- beta can significantly increase the expression level of miR-21 in cultured primary nasal epithelial cells. Futhermore, overexpression of miR-21 by lentivirus significantly disrupted the barrier function of nasal epithelial. Our result of dual luciferase reporter assay indicated that phosphatase and tensin homolog (PTEN), which involved in the regulation of mucosal barrier function, was regulated by miR-21 as a target gene. Therefore, we hypothesize that the increased expression of miR-21 contributes to the disruption of nasal epithelial barrier function in CRSwNP by targeting PTEN. This project will conduct deep research involving in histologic, cellular and molecular level combining with CRSwNP mouse model, thus to confirm the correlation between miR-21_PTEN and the aetiology of CRSwNP and the mechanism how miR-21_PTEN regulates the barrier function of nasal mucosa. This study will provide a research basis for further exploring the pathogenesis mechanism and new potential target for treatment of CRSwNP.

鼻黏膜上皮屏障功能的破坏是慢性鼻-鼻窦炎伴鼻息肉（chronic rhinosinusitis with nasal polyps，CRSwNP）发病过程中的重要因素。我们在前期研究中发现，miR-21在CRSwNP黏膜上皮中的表达较正常组显著升高，并发现在原代培养的鼻黏膜上皮细胞中IL-13、TGF-β可显著上调miR-21的表达；单独过表达miR-21可显著破坏上皮细胞的屏障功能；miR-21可以调控其靶基因PTEN的表达。因此，我们推测在CRSwNP中高表达的miR-21通过调控PTEN参与介导了鼻黏膜上皮屏障功能的破坏。本研究拟从组织-细胞-分子三个层面，结合小鼠动物模型，进一步明确miR-21、PTEN与CRSwNP发病的相关性，阐明miR-21通过靶基因PTEN参与调控鼻黏膜上皮细胞屏障功能的机制，从而为进一步探索CRSwNP的发病机制及潜在的治疗靶点提供研究基础。

慢性鼻窦炎伴鼻息肉（CRSwNP）发病率高、容易复发、严重影响患者的生活质量。鼻黏膜上皮屏障破坏和持续的炎症状态是CRSwNP的重要特点。本项目研究CRSwNP鼻黏膜中异常高表达的miR-21对上皮屏障和炎症的调控作用与机制，期望为治疗CRSwNP提供新靶标。本研究利用CRSwNP临床样本、原代鼻黏膜上皮细胞气液界面培养体系及CRSwNP小鼠模型，结合miR-21转染过表达及miR-21敲除小鼠，探索了鼻黏膜中miR-21的表达与CRSwNP发病及炎症内在型的关系，以及miR-21调控上皮屏障和炎症发生的作用与机制。我们的研究结果发现：①miR-21在CRSwNP患者鼻黏膜中的表达显著增加，并且与2型炎症内在型显著相关；②过表达miR-21能够破坏鼻黏膜的上皮屏障功能，并抑制靶基因PTEN的表达；③糖皮质激素治疗可以显著降低鼻黏膜中miR-21的表达水平；④在小鼠中敲除miR-21可减轻CRSwNP鼻黏膜的嗜酸性粒细胞浸润及2型炎症程度；⑤miR-21在鼻黏膜中的靶基因参与炎症反应的负调控过程。本项目明确了miR-21对CRSwNP鼻黏膜上皮屏障和炎症内在型的调控，证明了敲低miR-21的表达可以显著缓解CRSwNP鼻黏膜的炎症程度，从而为临床上治疗CRSwNP提供了新的重要靶点。