ABSTRACT
Di(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer that is metabolized to mono(2-ethylhexyl) phthalate (MEHP). Inhalation is an important exposure route for both phthalates, and their effects on lungs include inflammation, alteration of postnatal maturation (alveolarization), enlarged airspaces and cell differentiation changes, suggesting that alveolar epithelial cells-2 (AEC) are targets of phthalates. This study evaluated the cell progression, epithelial and mesenchymal markers, including surfactant secretion in A549 cells (AEC) that were exposed to DEHP (1-100⯵M) or MEHP (1-50⯵M) for 24-72â¯h. The results showed an increased cell proliferation at all concentrations of each phthalate at 24 and 48â¯h. Cell migration showed a concentration-dependent increase at 24 and 48â¯h of exposure to either phthalate and enlarged structures were seen. Decreased levels of both surfactants (SP-B/SP-C) were observed after the exposure to either phthalate at 48â¯h, and of SP-C positive cells exposed to MEHP, suggesting a loss of the epithelial phenotype. While a decrease in the epithelial marker E-cadherin and an increase in the mesenchymal marker fibronectin were observed following exposure to either phthalate. Our results showed that DEHP and MEHP altered the structure and migration of A549 cells and promoted the loss of the epithelial phenotype.
Subject(s)
Alveolar Epithelial Cells/drug effects , Cell Dedifferentiation/drug effects , Diethylhexyl Phthalate/analogs & derivatives , Diethylhexyl Phthalate/toxicity , Plasticizers/toxicity , Pulmonary Surfactant-Associated Protein B/antagonists & inhibitors , Pulmonary Surfactant-Associated Protein C/antagonists & inhibitors , A549 Cells , Alveolar Epithelial Cells/cytology , Alveolar Epithelial Cells/metabolism , Antigens, CD , Biomarkers/metabolism , Cadherins/antagonists & inhibitors , Cadherins/metabolism , Cell Movement/drug effects , Cell Proliferation/drug effects , Cell Shape/drug effects , Cell Size/drug effects , Cell Survival/drug effects , Fibronectins/agonists , Fibronectins/metabolism , Humans , Kinetics , Pulmonary Surfactant-Associated Protein B/metabolism , Pulmonary Surfactant-Associated Protein C/metabolismABSTRACT
A rat model of ventilation-induced lung injury (VILI) during anesthesia was generated to investigate the potential role and possible mechanism of interleukin-10 (IL-10) and recombinant human keratinocyte growth factor-2 (rhKGF-2) in protecting anesthetized rats against VILI. A total of 50 male SD rats were randomly divided into 5 groups (N = 10 each): control, VILI, IL-10, rhKGF-2, and IL-10 + rhKGF-2. The VILI (model) group was generated via ventilation, with a tidal volume of 20 mL/kg. Rats in the IL-10 and rhKGF-2 groups received 8 mg/kg IL-10 and 5 mg/kg rhKGF-2, respectively, prior to ventilation. The rats in the IL-10 + rhKGF-2 group received both 8 mg/kg IL-10 and 5 mg/kg rhKGF-2 72 h before ventilation. The total number of nucleated cells and neutrophils in the bronchial alveolar lavage fluid was quantified, and the pathological changes in the pulmonary tissues examined by hematoxylin and eosin staining. The transcript and protein levels of surfactant protein C (SP-C) in lung tissues were detected by real-time polymerase chain reaction and western blot analyses. The SP-C mRNA expression in both IL-10 and rhKGF-2 groups was similar to that in the VILI group. However, this was significantly elevated in the combined treatment group (P < 0.05), indicating that IL-10 and rhKGF-2 could synergistically protect the lung tissue from VILI via the enhancement of SP-C mRNA expression in lung tissues. The protein assay showed a decreased level of infiltration and activation of inflammatory cells, in addition to increased expression of SP-C, thereby confirming the efficacy of this treatment in preventing VILI during anesthesia.