title: Prenatal cigarette smoke exposure effects on apoptotic and nicotinic acetylcholine receptor expression in the infant mouse brainstem.
abstract: Infants exposed to cigarette smoked during pregnancy into infancy have increased respiratory and cardiac abnormalities. Nicotine, the major neurotoxic component of cigarette smoke, induces its actions by binding to nicotinic acetylcholine receptors (nAChR), with one downstream effect being increased apoptosis. Using a pre- into post- natal cigarette smoke exposure mouse model (SE), we studied the immunohistochemical expression of nAChR subunits α2, α3, α4, α5, α7, α9, β1 and β2 and two markers of apoptosis, active caspase-3 and TUNEL, in seven nuclei of the medulla and facial nucleus of the pons in male mice. Pups of dams exposed to two cigarettes (nicotine ≤1.2mg, CO ≤15mg) twice daily for six weeks prior to mating, during gestation and lactation (n=5; SE), were compared to pups exposed to air under the same condition (n=5; SHAM) at P20. Results showed that the hypoglossal nucleus had increased α3, α4, α7, α9, Casp-3 and TUNEL, dorsal motor nucleus of the vagus had increased α3, α5, α7, β1 and Casp-3, nucleus of the solitary tract had increased α3 but decreased α4, α5, β1 and apoptosis, cuneate nucleus had increased α3, β2 and Casp- 3, but decreased α5, nucleus of the spinal trigeminal tract had increased α3, α7, β1, lateral reticular nucleus had decreased β1, inferior olivary nucleus had increased β1 but decreased apoptosis, and the facial had increased α2, α3 and α7. This is the first study to demonstrate that nAChR subunits are affected following pre- into post-natal SE and that they simultaneously coincided with changes in apoptotic expression.
authors.affiliation: The BOSCH Institute, University of Sydney, Australia; Department of Medicine, Blackburn Building, DO6, University of Sydney, NSW 2006, Australia.
authors.forename: Arunnjah
authors.initials: A
authors.lastname: Vivekanandarajah
authors.affiliation: School of Life Sciences, Faculty of Science, University of Technology Sydney, Broadway, NSW 2007, Australia.
authors.forename: Yik Lung
authors.initials: YL
authors.lastname: Chan
authors.affiliation: School of Life Sciences, Faculty of Science, University of Technology Sydney, Broadway, NSW 2007, Australia.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: The BOSCH Institute, University of Sydney, Australia; Department of Medicine, Blackburn Building, DO6, University of Sydney, NSW 2006, Australia; The Children's Hospital, Westmead Sydney, NSW 2145, Australia. Electronic address: ritam@med.usyd.edu.au.
authors.forename: Rita
authors.initials: R
authors.lastname: Machaalani
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D001933:Brain Stem / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000473:pathology; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D009538:Nicotine / Q000633:toxicity*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects / Q000139:chemically induced* / Q000473:pathology; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism*; D012907:Smoking / Q000009:adverse effects
chemical_list: D021122:Protein Subunits; D011978:Receptors, Nicotinic; D009538:Nicotine; D053148:Caspase 3
keywords: Caspase 3; Medulla; Nicotine; Smoking chamber; Sudden infant death syndrome (SIDS); TUNEL; nAChR