Targeting M2 Macrophages Alleviates Airway Inflammation and Remodeling in Asthmatic Mice via miR-378a-3p/GRB2 Pathway

Qiujie Wang; Luna Hong; Ming Chen; Jiangting Shi; Xiaoling Lin; Linjie Huang; Tiantian Tang; Yimin Guo; Xiaoqing Yuan; Shanping Jiang

doi:10.3389/fmolb.2021.717969

Targeting M2 Macrophages Alleviates Airway Inflammation and Remodeling in Asthmatic Mice via miR-378a-3p/GRB2 Pathway

Front Mol Biosci. 2021 Sep 13:8:717969. doi: 10.3389/fmolb.2021.717969. eCollection 2021.

Authors

Qiujie Wang^{1

2

3}, Luna Hong^{1

2

3}, Ming Chen^{1

2

3}, Jiangting Shi^{1

2

3}, Xiaoling Lin^{1

2

3}, Linjie Huang^{1

2

3}, Tiantian Tang^{1

2

3}, Yimin Guo^{1

2

3}, Xiaoqing Yuan^{2

4}, Shanping Jiang^{1

2

3}

Affiliations

¹ Division of Pulmonary and Critical Care Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
² Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China.
³ Institute of Pulmonary Diseases, Sun Yat-sen University, Guangzhou, China.
⁴ Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.

Abstract

Background: Asthma is a complex respiratory disease characterized by airway inflammation and remodeling. MicroRNAs (miRNAs) mediate various cellular processes including macrophage polarization and play an important role in the pathogenesis of asthma. In present study, we aimed to screen miRNA profiling involved in macrophage polarization and investigate its possible functions and mechanisms. Methods: An OVA-sensitized mouse model was established and 2-chloroadenosine (2-CA) was used to interfere with macrophages. The airway inflammation and remodeling were assessed. The identification and function of M2 alveolar macrophages were assessed by flow cytometry, RT-qPCR, arginase activity and co-culture experiment. Microarray screening was used to select miRNAs which were related to macrophage polarization and RNA interference (RNAi) technique was performed to confirm the function of the selected miRNA and its target gene. Results: Alveolar macrophages of asthmatic mice showed significant M2 polarization. 2-CA alleviated airway inflammation and remodeling as well as M2 polarization. In vitro, IL-4-induced M2 macrophages promoted the proliferation of α-SMA-positive cells. And miRNA profiling showed a remarkable increased expression of miR-378a-3p in IL-4 induced M2 macrophages. Dual luciferase reporter assay confirmed growth factor receptor binding protein 2 (GRB2) was a target gene of miR-378a-3p. A miR-378a-3p inhibitor and knockdown of GRB2 repolarized alveolar macrophages from M1 to M2 phenotype. Conclusion: Our findings suggest that miR-378a-3p/GRB2 pathway regulates the polarization of alveolar macrophages which acts as a potential therapeutic target for airway inflammation and remodeling in asthma.

Keywords: GRB2; M2 macrophages; airway inflammation; airway remodeling; asthma; miR-378a-3p.