BASIC SCIENCE: OBSTETRICS Human amnion epithelial cells as a treatment for inflammation-induced fetal lung injury in sheep Patricia Vosdoganes, BMedSc; Ryan J. Hodges, MBBS; Rebecca Lim, PhD; Alana J. Westover, BA/BSc; Rutu Y. Acharya, MBmSc; Euan M. Wallace, MD; Timothy J. M. Moss, PhD OBJECTIVE: The purpose of this study was to determine whether hu- man amnion epithelial cells (hAECs) can modulate the pulmonary devel- opmental consequences of intrauterine inflammation in fetal sheep that are exposed to intraamniotic lipopolysaccharide (LPS) injection. STUDY DESIGN: At 117 days’ gestation, fetal sheep (n = 16) received intraamniotic LPS (20 mg). hAECs were delivered at 0, 6, and 12 hours into the fetal jugular vein (n = 4), trachea (n = 4), or both (n = 4). Con- trols (n = 6) received equivalent administration of saline solution. Lungs were collected at 124 days. RESULTS: Intraamniotic LPS caused pulmonary inflammation and al- tered lung structure and function. hAECs attenuated changes in lung function and structure that had been induced by LPS: lung volume, 40 cm H 2 O(P  .05, intravenous + intratracheal hAECs vs LPS), tissue- to-airspace ratio (P  .05, intravenous + intratracheal hAECs vs LPS), and septal crest density (P  .001, all hAEC groups vs LPS). Leukocyte infiltration of the lungs was not reduced by hAECs; however, inflamma- tory cytokines were reduced (tumor necrosis factor–, P  .01, vs LPS; interleukin-1b, P  .01, vs LPS; interleukin-6, P  .01 vs LPS). Surfac- tant protein A and C messenger RNA was increased by LPS, although this was not statistically significant (P  .05 vs control); there were sig- nificant increases in all hAEC-treated animals (surfactant protein–A, P  .05 vs LPS; surfactant protein–C, P  .01 vs LPS). CONCLUSION: Human amnion epithelial cells attenuate the fetal pul- monary inflammatory response to experimental intrauterine inflamma- tion and reduce, but (as administered in our study) do not prevent, con- sequent alterations in lung development. Key words: bronchopulmonary dysplasia, human amnion epithelial cell, intrauterine inflammation, lipopolysaccharide, preterm birth Cite this article as: Vosdoganes P, Hodges RJ, Lim R, et al. Human amnion epithelial cells as a treatment for inflammation-induced fetal lung injury in sheep. Am J Obstet Gynecol 2011;205:156.e26-33. H uman amnion epithelial cells (hAECs) possess both regenerative 1 and an- tiinflammatory 2 properties and display low immunogenicity, 3 which have enabled their application in human therapies for wound repair, 4 burns, 5 and corneal sur- gery 6 without the development of im- mune rejection or need for immune sup- pression. 7 One benefit of hAECs is that they are sourced from placentae, which are usually discarded after birth. This re- solves many of the ethical and logistic limitations of other stem cells, including embryonic stem cells and bone marrow mesenchymal stem cells. With this in mind, we recently demonstrated a method for hAEC collection, isolation, and storage that is suitable for clinical use. 8 There are a number of characteristics that make hAECs an attractive cell ther- apy. Morphologically, hAECs maintain a normal karyotype in culture, have con- served long telomere lengths, and, unlike embryonic stem cells, do not form tera- tomas in vivo. 1 hAECs can also transdif- ferentiate down mesodermal, ectoder- mal, and endodermal tissue lineages. 1,7 Additionally, hAECs suppress lympho- cyte proliferation 9 and express negligible HLA antigens. 1 With regard to the lung, we 1 and others 10 have noted that hAECs express thyroid transcription factor Nkx2.1, which is an early lung development mar- ker. Furthermore, hAECs that are cultured in small airway growth media induce lung epithelial-specific gene expression. 8 Animal experiments have demonstrated the ability of hAECs to mitigate lung in- jury, likely through immune modulation and possibly integration into the alveolar epithelium. Specifically, in mouse models of bleomycin-induced pulmonary fibrosis, hAECs reduce acute expression of proin- flammatory cytokines tumor necrosis fac- tor-alpha (TNF-), IL (interleukin)-6 and -1, and interferon-, and subsequent lung scarring. 11,12 Given such findings in adult models, it is plausible that hAECs could modulate fetal lung injury that results from in utero infection. Inflammation during pregnancy is linked causally to preterm birth 13 and an increased risk of several diseases of pre- maturity. 14-17 In a series of sheep studies, intrauterine inflammation initiated a fe- tal pulmonary inflammatory response that resulted in increased surfactant pro- duction and structural lung changes, which improved preterm lung function in the short term. 18 These findings are From The Ritchie Centre, Monash Institute of Medical Research (Drs Lim, Wallace, and Moss and Ms Vosdoganes, Ms Westover, and Ms Acharya and Mr Hodges) and Department of Obstetrics and Gynaecology (Drs Wallace and Moss and Ms Vosdoganes), Monash University, Clayton, VIC, Australia. Received Dec. 16, 2010; revised March 17, 2011; accepted March 29, 2011. Reprints not available from the authors. Supported in part by NHMRC Project Grant 606483, NHMRC Career Development Award 303261 (T.J.M.M.). 0002-9378/$36.00 © 2011 Mosby, Inc. All rights reserved. doi: 10.1016/j.ajog.2011.03.054 Research www. AJOG.org 156.e26 American Journal of Obstetrics & Gynecology AUGUST 2011