  The complexity of the cells can be described and understood by a number of
networks such as protein-protein interaction, cytoskeletal, organelle,
signalling, gene transcription and metabolic networks. All these networks are
highly dynamic producing continuous rearrangements in their links, hubs,
network-skeleton and modules. Here we describe the adaptation of cellular
networks after various forms of stress causing perturbations, congestions and
network damage. Chronic stress decreases link-density, decouples or even
quarantines modules, and induces an increased competition between network hubs
and bridges. Extremely long or strong stress may induce a topological phase
transition in the respective cellular networks, which switches the cell to a
completely different mode of cellular function. We summarize our initial
knowledge on network restoration after stress including the role of molecular
chaperones in this process. Finally, we discuss the implications of
stress-induced network rearrangements in diseases and ageing, and propose
therapeutic approaches both to increase the robustness and help the repair of
cellular networks.
