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Laminin alpha1 chain synthesis in the mouse developing lung: requirement for epithelial-mesenchymal contact and possible role in bronchial smooth muscle development.

Schuger L, Skubitz AP, Zhang J, Sorokin L, He L - J. Cell Biol. (1997)

Bottom Line: In a set of functional studies, embryonic lung explants were cultured in the presence of monoclonal antibodies to laminin alpha1, alpha2, and beta/gamma chains.Lung explants exposed to monoclonal antibodies to laminin alpha1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle alpha actin and desmin.Taken together, our studies suggest that laminin alpha1 chain synthesis is regulated by epithelial-mesenchymal interaction and may play a role in airway smooth muscle development.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology and Laboratory Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.

ABSTRACT
Laminins, the main components of basement membranes, are heterotrimers consisting of alpha, beta, and gamma polypeptide chains linked together by disulfide bonds. Laminins-1 and -2 are both composed of beta1 and gamma1 chains and differ from each other on their alpha chain, which is alpha1 and alpha2 for laminin-1 and -2, respectively. The present study shows that whereas laminins-1 and -2 are synthesized in the mouse developing lung and in epithelial-mesenchymal cocultures derived from it, epithelial and mesenchymal monocultures lose their ability to synthesize the laminin alpha1 chain. Synthesis of laminin alpha1 chain however returns upon re-establishment of epithelial-mesenchymal contact. Cell-cell contact is critical, since laminin alpha1 chain is not detected in monocultures exposed to coculture-conditioned medium or in epithelial-mesenchymal cocultures in which heterotypic cell-cell contact is prevented by an interposing filter. Immunohistochemical studies on cocultures treated with brefeldin A, an inhibitor of protein secretion, indicated both epithelial and mesenchymal cells synthesize laminin alpha1 chain upon heterotypic cell- cell contact. In a set of functional studies, embryonic lung explants were cultured in the presence of monoclonal antibodies to laminin alpha1, alpha2, and beta/gamma chains. Lung explants exposed to monoclonal antibodies to laminin alpha1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle alpha actin and desmin. Taken together, our studies suggest that laminin alpha1 chain synthesis is regulated by epithelial-mesenchymal interaction and may play a role in airway smooth muscle development.

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Related in: MedlinePlus

Immunoblots demonstrating the presence of LM α1,  α2, β1, and γ1 chains in the developing lung (day 15 of gestation).  A polyclonal antibody against EHS LM that recognizes α1, α2,  β1, and γ1 chains (x-LM), a monoclonal antibody to the LM α1  chain (AL-4, x-LM α1), and a monoclonal antibody to LM α2  chain (4H8-2, x-LM α2) were used in these studies. LM-1 from  the EHS tumor and embryonic heart (rich in LM-2) served as  controls. Immunoblots with normal rabbit IgG or rat IgG did not  detect any protein bands.
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Figure 1: Immunoblots demonstrating the presence of LM α1, α2, β1, and γ1 chains in the developing lung (day 15 of gestation). A polyclonal antibody against EHS LM that recognizes α1, α2, β1, and γ1 chains (x-LM), a monoclonal antibody to the LM α1 chain (AL-4, x-LM α1), and a monoclonal antibody to LM α2 chain (4H8-2, x-LM α2) were used in these studies. LM-1 from the EHS tumor and embryonic heart (rich in LM-2) served as controls. Immunoblots with normal rabbit IgG or rat IgG did not detect any protein bands.

Mentions: Immunoblots using a polyclonal antibody against EHS LM (Fig. 1, x-LM) that recognizes both α1 and α2 chains, a monoclonal antibody to LM α1 chain (Fig. 1, x-LM α1), and a monoclonal antibody to LM α2 chain (Fig. 1, x-LM α2) demonstrated the presence of LM α1, α2, β1, and γ1 chains in the mouse developing lung. We noticed that β1 and γ1 chains frequently migrated with similar Mr producing a single band in minigels. However, the two bands were resolved in larger gels.


Laminin alpha1 chain synthesis in the mouse developing lung: requirement for epithelial-mesenchymal contact and possible role in bronchial smooth muscle development.

Schuger L, Skubitz AP, Zhang J, Sorokin L, He L - J. Cell Biol. (1997)

Immunoblots demonstrating the presence of LM α1,  α2, β1, and γ1 chains in the developing lung (day 15 of gestation).  A polyclonal antibody against EHS LM that recognizes α1, α2,  β1, and γ1 chains (x-LM), a monoclonal antibody to the LM α1  chain (AL-4, x-LM α1), and a monoclonal antibody to LM α2  chain (4H8-2, x-LM α2) were used in these studies. LM-1 from  the EHS tumor and embryonic heart (rich in LM-2) served as  controls. Immunoblots with normal rabbit IgG or rat IgG did not  detect any protein bands.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2139794&req=5

Figure 1: Immunoblots demonstrating the presence of LM α1, α2, β1, and γ1 chains in the developing lung (day 15 of gestation). A polyclonal antibody against EHS LM that recognizes α1, α2, β1, and γ1 chains (x-LM), a monoclonal antibody to the LM α1 chain (AL-4, x-LM α1), and a monoclonal antibody to LM α2 chain (4H8-2, x-LM α2) were used in these studies. LM-1 from the EHS tumor and embryonic heart (rich in LM-2) served as controls. Immunoblots with normal rabbit IgG or rat IgG did not detect any protein bands.
Mentions: Immunoblots using a polyclonal antibody against EHS LM (Fig. 1, x-LM) that recognizes both α1 and α2 chains, a monoclonal antibody to LM α1 chain (Fig. 1, x-LM α1), and a monoclonal antibody to LM α2 chain (Fig. 1, x-LM α2) demonstrated the presence of LM α1, α2, β1, and γ1 chains in the mouse developing lung. We noticed that β1 and γ1 chains frequently migrated with similar Mr producing a single band in minigels. However, the two bands were resolved in larger gels.

Bottom Line: In a set of functional studies, embryonic lung explants were cultured in the presence of monoclonal antibodies to laminin alpha1, alpha2, and beta/gamma chains.Lung explants exposed to monoclonal antibodies to laminin alpha1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle alpha actin and desmin.Taken together, our studies suggest that laminin alpha1 chain synthesis is regulated by epithelial-mesenchymal interaction and may play a role in airway smooth muscle development.

View Article: PubMed Central - PubMed

Affiliation: Department of Pathology and Laboratory Medicine, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.

ABSTRACT
Laminins, the main components of basement membranes, are heterotrimers consisting of alpha, beta, and gamma polypeptide chains linked together by disulfide bonds. Laminins-1 and -2 are both composed of beta1 and gamma1 chains and differ from each other on their alpha chain, which is alpha1 and alpha2 for laminin-1 and -2, respectively. The present study shows that whereas laminins-1 and -2 are synthesized in the mouse developing lung and in epithelial-mesenchymal cocultures derived from it, epithelial and mesenchymal monocultures lose their ability to synthesize the laminin alpha1 chain. Synthesis of laminin alpha1 chain however returns upon re-establishment of epithelial-mesenchymal contact. Cell-cell contact is critical, since laminin alpha1 chain is not detected in monocultures exposed to coculture-conditioned medium or in epithelial-mesenchymal cocultures in which heterotypic cell-cell contact is prevented by an interposing filter. Immunohistochemical studies on cocultures treated with brefeldin A, an inhibitor of protein secretion, indicated both epithelial and mesenchymal cells synthesize laminin alpha1 chain upon heterotypic cell- cell contact. In a set of functional studies, embryonic lung explants were cultured in the presence of monoclonal antibodies to laminin alpha1, alpha2, and beta/gamma chains. Lung explants exposed to monoclonal antibodies to laminin alpha1 chain exhibited alterations in peribronchial cell shape and decreased smooth muscle development, as indicated by low levels of smooth muscle alpha actin and desmin. Taken together, our studies suggest that laminin alpha1 chain synthesis is regulated by epithelial-mesenchymal interaction and may play a role in airway smooth muscle development.

Show MeSH
Related in: MedlinePlus