Partial SP-B deficiency perturbs lung function and causes air space abnormalities.

Abstract

Surfactant protein B (SP-B) is required for function of newborn and adult lung, and partial deficiency has been associated with susceptibility to lung injury. In the present study, transgenic mice were produced in which expression of SP-B in type II epithelial cells was conditionally regulated. Concentrations of SP-B were maintained at 60-70% of that normally present in control. Immunostaining for SP-B demonstrated cellular heterogeneity in expression of the protein. In subsets of type II cells in which SP-B staining was decreased, immunostaining for pro-SP-C was increased and lamellar body ultrastructure was disrupted, consistent with focal SP-B deficiency. Fluorescence-activated cell sorting analyses of freshly isolated type II cells identified a population of cells with low SP-B content and a smaller population with increased SP-B content, confirming nonuniform expression of the SP-B transgene. Focal air space enlargement, without cellular infiltration or inflammation, was observed. Pressure-volume curves indicated that maximal tidal volume was unchanged; however, hysteresis was modestly altered and residual volumes were significantly decreased in the SP-B-deficient mice. Chronic, nonuniform SP-B deficiency perturbed pulmonary function and caused air space enlargement.

• Authors: Lori L Nesslein, Kristin R Melton, Machiko Ikegami, Cheng-Lun Na, Susan E Wert, Ward R Rice, Jeffrey A Whitsett, Timothy E Weaver
• Journal: American journal of physiology. Lung cellular and molecular physiology (Am J Physiol Lung Cell Mol Physiol) Vol. 288 Issue 6 Pg. L1154-61 (Jun 2005) ISSN: 1040-0605 [Print] United States
• PMID: 15722377 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Pulmonary Surfactant-Associated Protein B

Topics

• Animals
• Epithelial Cells (metabolism)
• Female
• Lung (anatomy & histology, physiology)
• Lung Compliance
• Lung Volume Measurements
• Male
• Mice
• Mice, Transgenic
• Pulmonary Surfactant-Associated Protein B (deficiency, genetics)
• Respiratory Mechanics