The cellular mechanobiology of aging: from biology to mechanics

Abstract

Aging is a chronic, complicated process that leads to degenerative physical and biological changes in living organisms. Aging is associated with permanent, gradual physiological cellular decay that affects all aspects of cellular mechanobiological features, including cellular cytoskeleton structures, mechanosensitive signaling pathways, and forces in the cell, as well as the cell's ability to sense and adapt to extracellular biomechanical signals in the tissue environment through mechanotransduction. These mechanobiological changes in cells are directly or indirectly responsible for dysfunctions and diseases in various organ systems, including the cardiovascular, musculoskeletal, skin, and immune systems. This review critically examines the role of aging in the progressive decline of the mechanobiology occurring in cells, and establishes mechanistic frameworks to understand the mechanobiological effects of aging on disease progression and to develop new strategies for halting and reversing the aging process. Our review also highlights the recent development of novel bioengineering approaches for studying the key mechanobiological mechanisms in aging.

Passive repetitive stretching is associated with greater muscle mass and cross-sectional area in the sarcopenic muscle

“…Although prior studies have demonstrated that senescent muscles preserved the capacity to undergo hypertrophy, the ability to perceive and respond to mechanical inputs and translate them into biochemical signals, which is called “mechano-transduction,” was reportedly blunted during aging 11 . The impact of aging on the cellular mechano-transduction process is rooted in multiple factors such as modifications in cell cytoskeleton structures, alterations in mechanosensitive signaling, and the extracellular matrix environment 11 . Zotz et al found that 1 week of intermittent stretching in aged rats resulted in an unchanged muscle mass, accompanied by reduced fiber size 12 .…”

“…It is performed with minimal risk of injury at relatively light intensity as compared with resistant exercise and is used to prevent muscle disuse or enhance recovery from exposure to prolonged inactivity 8 , 10 . However, aging processes alter mechano-transduction, which is the ability for skeletal muscle cells to perceive and respond to mechanical inputs, indicating a perturbed load-induced plasticity for aged muscle hypertrophy 11 . As such, divergences in the stretching protocols applied also affect muscular hypertrophic adaptations.…”

Passive repetitive stretching increases skeletal muscle mass and myofiber cross-sectional area in senescence-accelerated model mouse

“…Although prior studies have demonstrated that senescent muscles preserved the capacity to undergo hypertrophy, the ability to perceive and respond to mechanical inputs and translate them into biochemical signals, which is called "mechano-transduction," was reportedly blunted during aging 11 . The impact of aging on the cellular mechano-transduction process is rooted in multiple factors such as modi cations in cell cytoskeleton structures, alterations in mechanosensitive signaling, and the extracellular matrix environment 11 . Zotz et al found that 1 week of intermittent stretching in aged rats resulted in an unchanged muscle mass, accompanied by reduced ber size 12 .…”

“…It is performed with minimal risk of injury at relatively light intensity as compared with resistant exercise and is used to prevent muscle disuse or enhance recovery from exposure to prolonged inactivity 8.10 . However, aging processes alter mechano-transduction, which is the ability for skeletal muscle cells perceive and respond to mechanical inputs, indicating a perturbed load-induced plasticity for aged muscle hypertrophy 11 . As such, divergences in the stretching protocols applied also affect muscular hypertrophic adaptations.…”

Cell Architecture-Dependent Constraints: Critical Safeguards to Carcinogenesis

“…Cells display drastic alterations of their shape during ageing, as observed in the epidermis [ 108 ]. Cellular ageing is also associated with significant cytoskeleton alterations [ 109 , 110 ]. Actin levels per se go significantly down in old rats and Drosophila when compared with younger individuals [ 111 , 112 ].…”