Ancel Julien, Belgacemi Randa, Perotin Jeanne-Marie, Diabasana Zania, Dury Sandra, Dewolf Maxime, Bonnomet Arnaud, Lalun Nathalie, Birembaut Philippe, Polette Myriam, Deslée Gaëtan, Dormoy Valérian
University of Reims Champagne-Ardenne, Inserm, P3Cell UMR-S 1250, SFR CAP-SANTE, 45 rue Cognacq-Jay, 51092, Reims, France.
Department of Pulmonary Medicine, University Hospital of Reims, Hôpital Maison Blanche, 51092, Reims, France.
Respir Res. 2020 Aug 7;21(1):207. doi: 10.1186/s12931-020-01478-x.
The hedgehog (HH) pathway has been associated with chronic obstructive pulmonary disease (COPD) in genome-wide association studies and recent studies suggest that HH signalling could be altered in COPD. We therefore used minimally invasive endobronchial procedures to assess activation of the HH pathway including the main transcription factor, Gli2, and the ligand, Sonic HH (Shh).
Thirty non-COPD patients and 28 COPD patients were included. Bronchial brushings, bronchoalveolar lavage fluid (BALF) and bronchial biopsies were obtained from fiberoptic bronchoscopy. Characterization of cell populations and subcellular localization were evaluated by immunostaining. ELISA and RNAseq analysis were performed to identify Shh proteins in BAL and transcripts on lung tissues from non-COPD and COPD patients with validation in an external and independent cohort.
Compared to non-COPD patients, COPD patients exhibited a larger proportion of basal cells in bronchial brushings (26 ± 11% vs 13 ± 6%; p < 0.0001). Airway basal cells of COPD subjects presented less intense nuclear staining for Gli2 in bronchial brushings and biopsies (p < 0.05). Bronchial BALF from COPD patients contained lower Shh concentrations than non-COPD BALF (12.5 vs 40.9 pg/mL; p = 0.002); SHH transcripts were also reduced in COPD lungs in the validation cohort (p = 0.0001).
This study demonstrates the feasibility of assessing HH pathway activation in respiratory samples collected by bronchoscopy and identifies impaired bronchial epithelial HH signalling in COPD.
在全基因组关联研究中，刺猬（HH）信号通路已被证实与慢性阻塞性肺疾病（COPD）相关，并且近期研究表明，COPD中HH信号可能发生改变。因此，我们采用微创支气管内检查方法，来评估HH信号通路的激活情况，包括主要转录因子Gli2和配体音猬因子（Shh）。
纳入30例非COPD患者和28例COPD患者。通过纤维支气管镜获取支气管刷检物、支气管肺泡灌洗液（BALF）和支气管活检组织。通过免疫染色评估细胞群体特征和亚细胞定位。采用酶联免疫吸附测定（ELISA）和RNA测序分析，以鉴定非COPD和COPD患者BAL中的Shh蛋白以及肺组织中的转录本，并在外部独立队列中进行验证。
与非COPD患者相比，COPD患者支气管刷检物中基底细胞比例更高（26±11% 对13±6%；p<0.0001）。COPD患者气道基底细胞在支气管刷检物和活检组织中Gli2的核染色强度较低（p<0.05）。COPD患者的支气管BALF中Shh浓度低于非COPD患者（12.5对40.9 pg/mL；p=0.002）；在验证队列中，COPD肺组织中的SHH转录本也减少（p=0.0001）。
本研究证明了通过支气管镜检查收集的呼吸道样本评估HH信号通路激活的可行性，并确定了COPD患者支气管上皮HH信号受损。
