Cell elasticity determines macrophage function.. Mus musculus

We report that macrophage elasticity plays a dominant role in bacterial phagocytosis, release of TNF-alpha, and production of reactive oxygen species. We show that macrophage elasticity is modulated by mechanical factors including substrate rigidity and substrate stretch. Changes in macrophage elasticity are dependent upon the degree of actin polymerization, and mediated in part through small rhoGTPase activity. Moreover, the functional effects of macrophage elasticity are not predicted by gene expression profiles. Overall design: Murine RAW 267.4 macrophages were separately grown on 2 matrix stiffness levels (1200, 150000 Pascals) for 0, 2, 6, 18 hours with 3 replicate sample experiments per condition. Total RNA extracted from the cells and profiled by microarrays. Keywords: Murine RAW 267.4 macrophage, matrix stiffness, phagocytosis, cell elasticity.