MicroRNA-98 reduces nerve growth factor expression in nicotine-induced airway remodeling [Gene Regulation]
Evolving evidence suggests that nicotine may contribute to impaired asthma control by stimulating expression of nerve growth factor (NGF), a neurotrophin associated with airway remodeling and airway hyperresponsiveness. We explored the hypothesis that nicotine increases NGF by reducing lung fibroblast (LF) microRNA-98 (miR-98) and PPARγ levels, thus promoting airway remodeling. Levels of NGF, miR-98, PPARγ, fibronectin 1 (FN1), endothelin-1 (EDN1, herein referred to as ET-1), and collagen (COL1A1 and COL3A1) were measured in human LFs isolated from smoking donors, in mouse primary LFs exposed to nicotine (50 μg/ml), and in whole lung homogenates from mice chronically exposed to nicotine (100 μg/ml) in the drinking water. In selected studies, these pathways were manipulated in LFs with miR-98 inhibitor (anti-miR-98), miR-98 overexpression (miR-98 mimic), or the PPARγ agonist rosiglitazone. Compared with unexposed controls, nicotine increased NGF, FN1, ET-1, COL1A1, and COL3A1 expression in human and mouse LFs and mouse lung homogenates. In contrast, nicotine reduced miR-98 levels in LFs in vitro and in lung homogenates in vivo. Treatment with anti-miR-98 alone was sufficient to recapitulate increases in NGF, FN1, and ET-1, whereas treatment with a miR-98 mimic significantly suppressed luciferase expression in cells transfected with a luciferase reporter linked to the putative seed sequence in the NGF 3′UTR and also abrogated nicotine-induced increases in NGF, FN1, and E...
Source: Journal of Biological Chemistry - Category: Chemistry Authors: Cherry Wongtrakool, Junsuk Ko, Andrew J. Jang, Kora Grooms, Sarah Chang, Cory Sylber, Beata Kosmider, Karim Bahmed, Michael R. Blackburn, Roy L. Sutliff, C. Michael Hart, Changwon Park, Toru Nyunoya, Michael J. Passineau, Qing Lu, Bum-Yong Kang Tags: Molecular Bases of Disease Source Type: research