Hypoxia-Inducible Factor-1α in SM22α-Expressing Cells Modulates Alveolarization

Got Oxygen? Studies on Mesenchymal Cell Hypoxia Inducible Factor-1α in Lung Development

“…Thus, HIF-1α signaling in myofibroblasts and smooth muscle cells may affect the size and number of alveoli and number of arterioles that branch into capillary networks, respectively. This is exactly what Barnes and colleagues ( 19 ) found: Mesenchymal cell HIF-1α expression was necessary to generate the normal alveolar and vascular densities.…”

“…The work presented herein by Barnes and colleagues ( 19 ) reveals new information toward a better understanding of lung development and the pathophysiology of bronchopulmonary dysplasia. The major findings are as follows.…”

“…It may seem odd that a mesenchymal cell, which is not necessarily in direct contact with alveolar epithelial and capillary endothelial cells, can have a profound effect on alveolar and vascular densities. Here, the authors ( 19 ) demonstrate that HIF-1α promotes the production of proangiogenic factors that have a paracrine effect, stimulating alveolar-capillary development. They report that the HIF-1α–deficient smooth muscle cells produce less of the proangiogenic factor, angiopoietin-2.…”

“…In this issue of the Journal , Barnes and colleagues (pp. 470–483 ) questioned whether mesenchymal cell HIF-1α contributes to the development of the alveolar-capillary network ( 19 ). To do this, they utilized SM22α-Cre recombinase mice that were crossed with HIF-1α flox/flox mice.…”