Research: Getting attached

17 December 2005

A protein receptor called beta-1 integrin is vital for the development of glandular tissue.

Integrins are cell surface proteins involved in adhesion to the extracellular matrices that surround cells. This process is vital for the creation and maturation of many tissues. Little is known, however, about the role of integrins in glandular epithelium, so Professor Charles Streuli and colleagues from the Wellcome Trust Centre For Cell-Matrix Research at the University of Manchester deleted the gene for beta-1 integrin and examined the effects on the development of mouse mammary glands and on mammary epithelial cells grown in culture.

The team found that the lack of beta-1 integrin affected the development of both acini (multicellular epithelial structures within the breast involved in milk production) and milk production (lactation). Lactation was defective even if the cells were allowed to differentiate before the gene was deleted. The epithelial cells exhibited abnormal adhesion in vivo and in tissue culture, and morphogenesis of the acini was defective.

It is well known that endocrine signals such as prolactin control the development and differentiation of the mammary gland in a temporal fashion, but this new study demonstrates the importance of adhesion mediated by beta-1 integrin in both the development of glandular epithelium and its biological function, lactation. Moreover, the study suggests ways in which integrins integrate with other cell-signalling molecules, thereby controlling the expression of tissue-specific genes.

External links

• Naylor MJ et al. Ablation of beta1 integrin in mammary epithelium reveals a key role for integrin in glandular morphogenesis and differentiation. J Cell Biol 2005;171(4):717–28.