Abstract

Congenital alveolar proteinosis (CAP) is a familial disorder fatal in full term newborns. We have identified a cause: deficiency of surfactant protein B (SP-B) one of four surfactant proteins secreted by the Type II pneumocyte (NEJM 328:406-410, 1993). In the first ten infants studied we identified two mutations in the SP-B gene - the more common, a frameshift mutation - 121ins2, or a 3' splice junction deletion (delta Ex 4) (J Pediatr: 125:43-50, 1994). Of great significance, our immunostaining of SP-B deficient lungs revealed an abnormal increase in Type II cell SP-C and alveolar luminal SP-A and SP-C; ultrastructure with immunogold localization showed accumulation of SP-A, SP-C and membranous (lipid) vesicles between Type II cells and their basement membrane indicating loss of Type II cell apical (polar) secretion of surfactant lipids and proteins. (Am J Respir Cell Mol Biol 11:230-239, 1994). These features provide unique insight into the importance of SP-B in Type II cell biology and suggest the hypotheses that SP-B: 1) is a regulatory factor in the synthesis, assembly and secretion of surfactant lipids and proteins SP-A and SP-C; 2) maintains the polarity of the cell essential for anatomical and structural integrity of the alveolar lining. To test these hypotheses we will use our immortalized, fully characterized, polarized, differentiated type II cell line T7, that secretes surfactant lipids and SP-A, SP-B, and SP-C, to: 1) produce an SP-B deficient cell line by infection with our SP-B anti-sense retroviral vector derived from Moloney murine leukemia virus; 2) compare in normal and SP-B deficient Type II cells (SP-B+, & SP-B-) the synthesis, assembly, polar secretion, reutilization of surfactant lipids and proteins SP-A, SP-B, and SP-C and the cell polarity, using radiolabelled choline and methionine incorporation with pulse-chase, phospholipid assay, immunoprecipitation, Western blotting and immunolocalization of surfactant with fluorescence, confocal and electron microscopy. These studies will greatly expand understanding of the role of SP-B in regulating surfactant metabolism and in maintaining the integrity of the alveolar epithelial and surfactant lining that are disrupted in many important diseases of the newborn and many forms of lung injury.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL055600-03
Application #
2750528
Study Section
Human Embryology and Development Subcommittee 1 (HED)
Project Start
1996-08-01
Project End
2001-07-31
Budget Start
1998-08-01
Budget End
1999-07-31
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost

  Institution

Name
Saint Louis University
Department
Pathology
Type
Schools of Medicine
DUNS #
City
Saint Louis
State
MO
Country
United States
Zip Code
63103

  Publications

Farberman, M M; Demello, D E; Hoffmann, J W et al. (2005) Morphologic changes in alveolar macrophages in response to UVEC-activated pulmonary Type II epithelial cells. Tissue Cell 37:213-22
Farberman, M M; Hoffmann, J W; Ryerse, J S et al. (2004) Diffusible signal to murine alveolar macrophages from lipopolysaccharide- and Escherichia coli-stimulated lung Type II epithelial cells. Inflamm Res 53:475-83
Zhao, Y; Al-Kaade, S; Keller, C A et al. (2002) Atelectasis--an unusual and late complication of lung transplant. Clin Transplant 16:233-9
Galambos, Csaba; Ng, Yin-Shan; Ali, Ayoob et al. (2002) Defective pulmonary development in the absence of heparin-binding vascular endothelial growth factor isoforms. Am J Respir Cell Mol Biol 27:194-203
Demello, Daphne E; Mahmoud, Sohir; Ryerse, Jan et al. (2002) Generation and characterization of a conditionally immortalized lung clara cell line from the H-2Kb-tsA58 transgenic mouse. In Vitro Cell Dev Biol Anim 38:154-64
Ryerse, J S; Hoffmann, J W; Mahmoud, S et al. (2001) Immunolocalization of CC10 in Clara cells in mouse and human lung. Histochem Cell Biol 115:325-32
deMello, D E; Lin, Z (2001) Pulmonary alveolar proteinosis: a review. Pediatr Pathol Mol Med 20:413-32
Ng, Y S; Rohan, R; Sunday, M E et al. (2001) Differential expression of VEGF isoforms in mouse during development and in the adult. Dev Dyn 220:112-21
deMello, D E; Reid, L M (2000) Embryonic and early fetal development of human lung vasculature and its functional implications. Pediatr Dev Pathol 3:439-49
deMello, D E; Mahmoud, S; Padfield, P J et al. (2000) Generation of an immortal differentiated lung type-II epithelial cell line from the adult H-2K(b)tsA58 transgenic mouse. In Vitro Cell Dev Biol Anim 36:374-82

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