Fig. 4.

(A) MMPs regulate lung bud branching in lung organ cultures. Numbers above the panels represent the number of days in culture. E11.5 lung buds were isolated from timed-pregnancies and placed in serum-free media in the presence or absence of MMP inhibitor (GM6001). Following four days growth in vitro, lung buds show retardation of branching in the presence of MMP inhibitor as compared to control. (B) Analysis of branching inhibition. Quantification by counting the number of newly formed secondary and tertiary branches in E10.5 (n=4) and E11.5 (n=3) whole lungs following four days of culture. *P≤0.05 (Student’s t-test).