A transgenic mouse model for studying the lineage relationships and differentiation program of type II pneumocytes at various stages of lung development

• Published in: The Journal of biological chemistry Vol. 268; no. 13; pp. 9762 - 9770
• Main Authors: HANSBROUGH, J. R, FINE, S. M, GORDON, J. I
• Format: Journal Article
• Language: English
• Published: Bethesda, MD American Society for Biochemistry and Molecular Biology 05-05-1993
• Subjects: Aging - physiology; Animals; Base Sequence; beta-Galactosidase - analysis; beta-Galactosidase - biosynthesis; beta-Galactosidase - genetics; Biological and medical sciences; Cell Differentiation; Cell differentiation, maturation, development, hematopoiesis; Cell physiology; Cloning, Molecular; Embryonic and Fetal Development; Epithelial Cells; Epithelium - physiology; Female; Flow Cytometry; Fundamental and applied biological sciences. Psychology; H-2 Antigens - analysis; H-2 Antigens - biosynthesis; H-2 Antigens - genetics; Lung - cytology; Lung - embryology; Lung - growth & development; Male; Mice; Mice, Transgenic; Molecular and cellular biology; Molecular Sequence Data; Pedigree; Recombinant Fusion Proteins - analysis; Recombinant Fusion Proteins - biosynthesis; Restriction Mapping; Pneumocyte; Vertebrata; Mammalia; Mouse; Immunocytochemistry; Lung; Rodentia; Transgenic animal; Development; Epithelial cell; Cell differentiation
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1016/S0021-9258(18)98413-9

A pedigree of transgenic mice has been characterized that contains a H2-Kb/LacZ fusion gene that exhibits integration site-dependent
expression from the earliest stages of lung development through adulthood. Histochemical and immunocytochemical studies indicate
that the LacZ reporter appears throughout the pulmonary endoderm by embryonic day 11 (E11). A proximal-to-distal wave of extinction
of transgene expression occurs during E13-14 that parallels the wave of cytodifferentiation of the pulmonary endoderm. By
E16, the LacZ reporter is restricted to the distal portion of epithelial tubules and by birth to scattered cells located in
alveoli. Crude epithelial cell suspensions were prepared from lungs harvested from E16 and 14 day postnatal transgenic mice,
labeled with the fluorescent LacZ substrate fluorescein di-(beta-galactopyranoside), and the LacZ expressing population isolated
by fluorescence-activated cell sorting. Electron microscopic, immunocytochemical and histochemical studies of this purified
cell population establish that type II pneumocytes are the only cell lineage that support H2-Kb/LacZ expression in the mature
postnatal lung. Fluorescence-activated cell sorting of E16 lung suspensions yielded a homogeneous population of cells that
produced surfactant protein A, that could be maintained in cell culture, and that are likely precursors of adult type II pneumocytes.
Together these studies indicate that (i) expression of the transgene in this pedigree of mice provides a marker for describing
early differentiation of the pulmonary epithelium; (ii) the transgene may be useful as an enhancer trap to isolate cis-acting
sequences that regulate gene transcription within this lineage; (iii) the LacZ reporter expression can be used to purify specific
embryonic pulmonary epithelial cell populations; and (iv) primary cultures of these embryonic populations represent a potentially
useful model system for analyzing the cellular components and signaling pathways necessary to support and complete passage
through the type II pneumocyte differentiation program.