Nucleotide-Oligomerizing Domain-1 Activation Exaggerates Cigarette Smoke-Induced Chronic Obstructive Pulmonary-Like Disease in Mice

Guangchao Han, Min Li, Junfeng Du, Yang Chen, Chen Xu Department of Respiratory and Critical Care Medicine, Cangzhou Central Hospital, Cangzhou, 061000, Hebei, People’s Republic of ChinaCorrespondence: Guangchao HanDepartment of Respiratory and Critical Care Medicine, Cangzhou Central Hospital, No. 16 Xinhua West Road, Cangzhou, 061000, Hebei, People’s Republic of ChinaTel +86-15833371555Email guangchao1020@126.comIntroduction: Chronic obstructive pulmonary disease (COPD) is a progressive condition related to abnormal inflammatory responses. As an inflammatory driver, nucleotide-binding oligomerizing domain-1 (NOD1) is highly expressed in pulmonary inflammatory cells; however, the roles of NOD1 in COPD are unknown.Methods: A COPD mouse model was established by lipopolysaccharides tracheal instillation plus cigarette smoke (CS) exposure. NOD1 activation was induced by C12-iE-DAP (iE) treatment in both control and COPD mice. Inflammatory infiltration, pulmonary histological damage and gene expression were measured to evaluate the lung function of treated mice.Results: The results showed that NOD1 was up-regulated in COPD mice, which significantly exaggerated CS-induced impairment of lung function, demonstrated by increased airway resistance, functional residual capacity and pulmonary damages. Mechanistically, NOD1 activation strongly activated the TLR4/NF-κB signaling pathway and then increased inflammatory responses and promoted the secretion of inflammatory cytokines.Discussion: This study demonstrates that NOD1 is an important risk factor in the progression of COPD; therefore, targeting NOD1 in lung tissues is a potential strategy for COPD treatment.Keywords: COPD, pulmonary damage, inflammation, NOD1, TLR4/NF-κB signaling