Mechanical Regulation and Maintenance of Organismal Homeostasis - Scientific Basis for Health Promotion by Physical Motility and Exercise

Abstract

Mechanical stresses play various different roles in regulating organismal functions, depending on the situation when and where they are borne. Cell signaling related to ‘straining’ mechanical stresses, such as cell stretching, pressurizing, cytoskeletal tensioning, adhesion to stiff substrate, and high traction force generation, is imperative in the ‘constructive’ phase of tissues and organs, including development, regeneration and repair. However, once steady state is reached upon completion of tissue/organ formation, straining mechanical stress often causes failure of organismal homeostasis, such as inflammation and cancer. In contrast to such ‘detrimental’ aspect of straining stress, relaxing mechanical stress contributes to maintenance of homeostasis. Collectively, balance and integration between straining and relaxing mechanical stresses is vital, whose disruption gives rise to diseases, particularly those related to ageing or physical inactivity (Figure-1).