July 7, 2011

Totally tubular! If Bill and Ted had an excellent adventure in the human body, you can be certain that they’d learn about the most excellent tube structures throughout the body. From the veins that carry our blood to the branching tubules in our lungs, tubes are very important structures. A recent paper looks at the role of adhesion proteins during tubule formation.

During development, dramatic rearrangements of epithelial sheets results in the formation of branched tubules, as seen in kidney, lung, and mammary gland tissue. As one might expect, these rearrangements require coordination of several cellular events such as cell division, migration, polarization, and adhesion. A recent paper describes the role of two adhesion proteins, E-cadherin and cadherin-6, in tubule formation. Jia and colleagues found that cadherin-6 is important in inhibiting tubule formation, while E-cadherin is important in the formation of a tubule’s lumen (its inside cavity). Images above show the use of cell cysts as a model for epithelial tubule and lumen formation, with fluorescent tags showing a lateral marker (blue) and lumen-facing apical markers (green and red). Samples of control cysts, cysts without cadherin-6, E-cadherin, or both are shown (moving left to right). Although the mutant cysts appear abnormal, polarization was not disrupted in cysts without either cadherin (although multiple lumens are visible in cysts lacking E-cadherin). The polarization of cysts lacking both cadherins, however, was completely disrupted.

Jia, L., Liu, F., Hansen, S., ter Beest, M., & Zegers, M. (2011). Distinct roles of cadherin-6 and E-cadherin in tubulogenesis and lumen formation Molecular Biology of the Cell, 22 (12), 2031-2041 DOI: 10.1091/mbc.E11-01-0038