title: Infant formula alters surfactant protein A (SP-A) and SP-B expression in pulmonary epithelial cells.
abstract: Surfactant proteins A (SP-A) and SP-B are critical in the ability of pulmonary surfactant to reduce alveolar surface tension and provide innate immunity. Aspiration of infant milk formula can lead to lung dysfunction, but direct effects of aspirated formula on surfactant protein expression in pulmonary cells have not been described. The hypothesis that infant formula alters surfactant protein homeostasis was tested in vitro by assessing surfactant protein gene expression in cultured pulmonary epithelial cell lines expressing SP-A and SP-B that were transiently exposed (6 hr) to infant formula. Steady-state levels of SP-A protein and mRNA and SP-B mRNA in human bronchiolar (NCI-H441) and mouse alveolar (MLE15) epithelial cells were reduced in a dose-dependent manner 18 hr after exposure to infant formula. SP-A mRNA levels remained reduced 42 hr after exposure, but SP-B mRNA levels increased 10-fold. Neither soy formula nor non-fat dry milk affected steady-state SP-A and SP-B mRNA levels; suggesting a role of a component of infant formula derived from cow milk. These results indicate that infant formula has a direct, dose-dependent effect to reduce surfactant protein gene expression. Ultimately, milk aspiration may potentially result in a reduced capacity of the lung to defend against environmental insults.
authors.affiliation: Division of Neonatal-Perinatal Medicine, Department of Pediatrics, The University of Texas Health Science Center at Houston, Houston, Texas 77030, USA.
authors.forename: Maurice G
authors.initials: MG
authors.lastname: Chen
authors.forename: Constance L
authors.initials: CL
authors.lastname: Atkins
authors.forename: Shirley R
authors.initials: SR
authors.lastname: Bruce
authors.forename: Amir M
authors.initials: AM
authors.lastname: Khan
authors.forename: Yuying
authors.initials: Y
authors.lastname: Liu
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Alcorn
mesh_terms: D000818:Animals; D055745:Bronchioles / Q000187:drug effects* / Q000378:metabolism; D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000494:pharmacology*; D051379:Mice; D011650:Pulmonary Alveoli / Q000187:drug effects* / Q000378:metabolism; D037662:Pulmonary Surfactant-Associated Protein A / Q000096:biosynthesis* / Q000235:genetics; D037701:Pulmonary Surfactant-Associated Protein B / Q000096:biosynthesis* / Q000235:genetics; D045730:Soy Foods
chemical_list: D037662:Pulmonary Surfactant-Associated Protein A; D037701:Pulmonary Surfactant-Associated Protein B