title: Side-stream tobacco smoke-induced airway hyperresponsiveness in early postnatal period is involved nerve growth factor.
abstract: Epidemiological studies have shown that children are more susceptible to adverse respiratory effects of passive smoking than adults. The goal of this study is to elucidate the possible neural mechanism induced by exposure to passive smoking during early life. Postnatal day (PD) 2 and PD 21 mice were exposed to side-stream tobacco smoke (SS), a surrogate to secondhand smoke, or filtered air (FA) for 10 consecutive days. Pulmonary function, substance P (SP) airway innervation, neurotrophin gene expression in lung and nerve growth factor (NGF) release in bronchoalveolar lavage (BAL) fluid were measured at different times after the last SS or FA exposure. Exposure to SS significantly altered pulmonary function in PD2, accompanied with an enhanced SP innervation in airway. However, exposure to SS during the later developmental period (PD21) did not appear to affect pulmonary function and SP innervation of the airways. Interestingly, SS exposure in PD2 group significantly induced an increased gene expression on NGF, and decreased NGF receptor P75 in lung; parallel with high levels of NGF protein in BAL. Furthermore, pretreatment with NGF antibody significantly diminished SS-induced airway hyperresponsivenss and the increased SP airway innervation in the PD2 group. These findings suggest that enhanced NGF released in the lung contributes to SS-enhanced SP tracheal innervation and airway responsiveness in early life.
authors.affiliation: Department of Neurobiology and Anatomy, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, United States. Electronic address: zwu@hsc.wvu.edu.
authors.forename: Z-X
authors.initials: ZX
authors.lastname: Wu
authors.affiliation: Department of Neurobiology and Anatomy, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, United States.
authors.forename: D D
authors.initials: DD
authors.lastname: Hunter
authors.affiliation: Department of Neurobiology and Anatomy, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, United States.
authors.forename: T P
authors.initials: TP
authors.lastname: Batchelor
authors.affiliation: Department of Neurobiology and Anatomy, Robert C. Byrd Health Sciences Center, West Virginia University, Morgantown, WV 26506, United States.
authors.forename: R D
authors.initials: RD
authors.lastname: Dey
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D051379:Mice; D008813:Mice, Inbred ICR; D020932:Nerve Growth Factor / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D018040:Receptors, Neurokinin-1 / Q000378:metabolism*; D012130:Respiratory Hypersensitivity / Q000139:chemically induced* / Q000517:prevention & control; D012137:Respiratory System / Q000294:innervation*; D013373:Substance P / Q000378:metabolism*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*
chemical_list: D017475:Receptors, Nerve Growth Factor; D018040:Receptors, Neurokinin-1; C517634:Ngfr protein, mouse; D014028:Tobacco Smoke Pollution; D013373:Substance P; D020932:Nerve Growth Factor
keywords: Airway innervation; Asthma; Neurokinin receptor; Substance P