Exosomal transfer of activated neutrophil-derived lncRNA CRNDE promotes proliferation and migration of airway smooth muscle cells in asthma
Xiaoyu Zhang, Zhuochang Chen, Nan Li, Zhihua Wang, Yali Guo, Cuijie Tian, Dongjun Cheng, Xueyi Tang, Luo-xian Zhang
Abstract
Activated neutrophil-derived exosomes reportedly contribute to the proliferation of airway smooth muscle cells (ASMCs), thereby aggravating the airway wall remodeling during asthma; however, the specific mechanism remains unclear. Lipopolysaccharide (LPS)-EXO and si-CRNDE-EXO were extracted from the media of human neutrophils treated with LPS and LPS + si-CRNDE (a siRNA targets long non-coding RNA CRNDE), respectively. Human ASMCs were co-cultured with LPS-EXO or si-CRNDE-EXO, and cell viability, proliferation and migration were measured. The interplay of colorectal neoplasia differentially expressed (CRNDE), inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ) and nuclear receptor subfamily 2 group C member 2 (TAK1) was explored using RNA immunoprecipitation (RIP) and Co-IP assays. A mouse model of asthma was induced using ovalbumin. CRNDE was upregulated in LPS-EXO and successfully transferred from LPS-treated neutrophils to ASMCs through exosome. Mechanically, CRNDE loaded in LPS-EXO reinforced TAK1-mediated IKKβ phosphorylation, thereby activating the nuclear factor kappa B (NF-κB) pathway. Functionally, silencing CRNDE in LPS-EXO, an IKKβ inhibitor, and an NF-κB inhibitor all removed the upregulation of cell viability, proliferation and migration induced by LPS-EXO in ASMCs. In the end, the in vivo experiment demonstrated that CRNDE knockdown in neutrophils effectively reduced the thickness of bronchial smooth muscle in a mouse model for asthma. Activated neutrophils-derived CRNDE was transferred to ASMCs through exosomes and activated the NF-κB pathway by enhancing IKKβ phosphorylation. The latter promoted the proliferation and migration of ASMCs and then contributed to airway remodeling in asthma.