Mesenchymal stromal cells from neonatal tracheal aspirates demonstrate a pattern of gene expression consistent with a lung origin

Expression profiling of lung derived mesenchymal stromal cells to lung fibrblasts and cord blood derived mesenchymal stromal cells We have previously isolated mesenchymal stromal cells (MSCs) from the tracheal aspirates of premature neonates with respiratory distress. While isolation of MSCs correlates with the development of bronchopulmonary dysplasia, the physiologic role of these cells remains unclear. To address this, we further characterized the cells, focusing on the issues of gene expression, origin and cytokine expression. Microarray comparison of early passage neonatal lung MSC gene expression to cord blood MSCs and human fetal and neonatal lung fibroblast lines demonstrated that the neonatal lung MSCs differentially expressed 971 gene probes compared to cord blood MSCs, including the transcription factors Tbx2, Tbx3, Wnt5a, FoxF1 and Gli2, each of which have been associated with lung development. Compared to lung fibroblasts, 710 gene probe transcripts were differentially expressed by the lung MSCs, including IL-6 and IL-8/CXCL8. Further, neonatal lung MSCs exhibited a pattern of Hox gene expression distinct from cord-blood MSCs but similar to human fetal lung fibroblasts, consistent with a lung origin. Together, these data suggest that MSCs isolated from neonatal tracheal aspirates originate in the lung and are distinct from lung fibroblasts.