Victor E. Laubach, PhD
Compensatory hyperplasia following pneumonectomy
Pneumonectomy (surgical removal of a lung) is a life-saving procedure in patients who cannot otherwise be cured such as emphysema, cystic fibrosis and lung cancer. In animal studies, and even in some patients, pneumonectomy induces rapid hyperplastic growth of the remaining lung. This adaptive growth referred to as compensatory lung growth, results in restoration of total lung volume, compliance, mass, DNA, protein, alveolar number, and normal lung cell populations. While it is well established that pneumonectomy results in rapid compensatory growth of the remaining lung, little is understood as to the early changes in the lung following such a procedure and to the stimuli and molecular mediators of this growth. Recent studies from the Laubach laboratory indicate that nitric oxide is an important regulator of compensatory lung growth, and they have shown that inhibition of angiogenesis impairs lung growth. In addition, the laboratory has shown that compensatory lung growth is receptive to exogenous growth factors, which can significantly augment this growth. Currently, research in the laboratory is focused on the role of angiogenesis in compensatory lung growth. For example, they have shown that right pneumonectomy induces arterial growth in the left lungs of adult rats, which is proportionate to the number of lobes removed. Pulmonary hypertension and vascular remodeling also occurs following right pneumonectomy. Identification of the molecular mediators in compensatory lung growth will not only advance the fields of lung biology and transplantation, but will permit the advancement of future therapies for lung injury, pulmonary hypertension, respiratory failure, transplantation, and even stimulation of growth in patients with minimal pulmonary tissues left after lung resection or disease, including cancer.