Expression Patterns of Laminin α1 and α5 in Human Lung during Development

Pierce R.A, Griffin G.L., Miner J.H., Senior R.M.
Am. J. Respir. Cell Mol. Biol., 2000

To determine the temporal and spatial patterns of laminin α1 and laminin α5 in developing human lung, the authors prepared complementary DNA probes specific for laminin α1 and α5 messenger RNAs (mRNAs). Laminin α1 mRNA was prominent in first trimester fetal lung but was not detectable at 23 wk or at later times. In contrast, laminin α5 mRNA was readily detected in early fetal lung and remained present thereafter. Immunohistochemical staining demonstrated laminin a 1 only in early fetal lung, whereas laminin α5 was persistent from the early fetal period. In situ hybridization localized laminin α1 expression to the distal epithelium in the first-trimester lung, and laminin α5 to all epithelium and developing pulmonary arteries from the first trimester through the perinatal period. These studies indicate that laminin α1 expression is restricted to early human lung morphogenesis, whereas the expression of laminin α5 in the human lung is continuous from early lung development through adult life. It is evident that laminin α1 and laminin α5 have different roles in the development of the human lung.