Hypergravity effects on proliferation and differentiation of C2C12 muscle-like cells

This study aimed at the investigation of muscle-like cell behaviour in conditions of altered gravity. C2C12 cells underwent stimulations by different hypergravity intensities (5, 10, 20 g) in the Large Diameter Centrifuge of the European Space Agency (ESA), and their features in terms of proliferation and differentiation were compared to control cultures carried out at normal earth gravity force. Proliferation was investigated determining the DNA content in the cultures. A positive correlation between DNA concentration (and therefore cell proliferation) and g values was found. Moreover, actin staining allowed for a qualitative study of the cytoskeleton rearrangement following hypergravity exposure. Differentiation was evaluated on confluent cultures treated with analogous protocol. Also in this case, hypergravity seems to positively affect the differentiation process of C2C12 cells and their fusion in myotubes. The evaluation of myosin expression by immunocytochemistry suggested an accelerated differentiation process following exposure of cells to different g values.