Control of basement membrane remodeling and epithelial branching morphogenesis in embryonic lung by Rho and cytoskeletal tension.
Local alterations in the mechanical compliance of the basement membrane that alter the level of isometric tension in the cell have been postulated to influence tissue morphogenesis. To explore whether cell tension contributes to tissue pattern formation in vivo, we modulated cytoskeletal force generation in embryonic mouse lung (embryonic days 12-14) rudiments using inhibitors of Rho-associated kinase (ROCK), myosin light chain kinase, myosin ATPase, and microfilament integrity, or a Rho stimulator (cytotoxic necrotizing factor-1). Tension inhibition resulted in loss of normal differentials in basement membrane thickness, inhibition of new terminal bud formation, and disorganization of epithelial growth patterns as well as disruption of capillary blood vessels. In contrast, increasing cell tension through Rho activation, as confirmed by quantitation of myosin light chain phosphorylation and immunohistocytochemical analysis of actin organization, accelerated lung branching and increase capillary elongation. These data suggest that changes in cytoskeletal tension mediated by Rho signaling through ROCK may play an important role in the establishment of the spatial differentials in cell growth and extracellular matrix remodeling that drive embryonic lung development.
Moore
Kimberly A
KA
Vascular Biology Program, Department of Surgery, Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Polte
Tom
T
Huang
Sui
S
Shi
Bin
B
Alsberg
Eben
E
Sunday
Mary E
ME
Ingber
Donald E
DE
D000199:Actins / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000737:chemistry; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001427:Bacterial Toxins / Q000494:pharmacology; D001485:Basement Membrane / Q000502:physiology*; D015153:Blotting, Western; D002196:Capillaries / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D003599:Cytoskeleton / Q000378:metabolism*; D003720:Densitometry; D004305:Dose-Response Relationship, Drug; D029968:Escherichia coli Proteins / Q000494:pharmacology; D005109:Extracellular Matrix / Q000378:metabolism; D007150:Immunohistochemistry; D008168:Lung / Q000196:embryology*; D051379:Mice; D018994:Myosin Light Chains / Q000737:chemistry; D009218:Myosins / Q000737:chemistry; D010766:Phosphorylation; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D013997:Time Factors; D020741:rho GTP-Binding Proteins / Q000378:metabolism
D000199:Actins; D000577:Amides; D001427:Bacterial Toxins; D029968:Escherichia coli Proteins; D018994:Myosin Light Chains; D011725:Pyridines; C060296:cytotoxic necrotizing factor type 1; C108830:Y 27632; D000251:Adenosine Triphosphatases; D009218:Myosins; D020741:rho GTP-Binding Proteins