Abstract
It has recently been proposed that the cell nucleus acts as a mechanosensor, and the changes in nuclear mechanical environment affect cell functions. However, the physiological roles of the nuclear deformation are unclear at this stage. Here we investigated the effects of nuclear deformation on cellular events, such as cell proliferation, using microfabricated substrates with an array of micropillars. We found that the proliferation of vascular smooth muscle cells (SMCs) but not cervical cancer HeLa cells was dramatically inhibited on the micropillar substrates, even though remarkable nuclear deformation was observed in both types of cells. Mechanical testing with AFM revealed that SMC nuclei were over three times stiffer than those of HeLa, which consequently increased the nuclear mechanical resistance against extracellular microstructures. These results indicate that the proliferation inhibition resulted from deformation of the nucleus, which might be exposed to higher internal stress during nuclear deformation. This nuclear stress-induced inhibition of cell proliferation scarcely occurred in HeLa with deformable nuclei.
