Cell Senescence In Vitro

Abstract

Cell senescence in vitro refers to the multitude of physiological, structural, biochemical and molecular changes that occur progressively during serial subcultivation of normal diploid cells, culminating in the permanent cessation of cell division. The whole duration of serial passaging is considered as the process of cellular ageing, and the end-stage irreversible growth arrest is termed as replicative senescence. The limited proliferative capacity of normal, diploid and differentiated cells is also known as the Hayflick limit, and the overall phenomenon is called the Hayflick phenomenon. A progressive loss of global deoxyribonucleic acid (DNA) methylation and of telomeres is considered to be the critical determinants of the Hayflick limit. However, in vivo, it is not the absolute number of senescent cells which is responsible for agerelated impairments, but it is the drift in cell functions occurring during repeated cell division that is relevant to ageing and age-related diseases. Cell senescence in the body is also considered to be a regulatory mechanism against cancer.

Extracellular Matrix Modulates Morphology, Growth, Oxidative Stress Response and Functionality of Human Skin Fibroblasts during Aging In Vitro

“…However, there were clear-cut serially passage-related differences between the morphology of early passage young cells and late passage near senescent old cells, similar to the one reported in numerous publications on cellular senescence [1]. As compared with Y-FSF, O-FSF grown on plastic surface was highly enlarged, irregular, vacuolated and heterogeneous ( Figure 1A and B).…”

“…auto fluorescence indicating the level of oxidative damaged macromolecules and protein-lipid conjugates. These parameters are well known to increase during cellular aging and a decrease in these characteristics can be an indicator of rejuvenation [1,22]. Figure 4 show that there was a significant decrease in the cell size, granularity and autofluorescence, with a general shift to the left in the cell population for these 3 characteristics.…”

“…The Hayflick phenomenon of cellular aging and replicative senescence observed in serially passaged normal diploid differentiated cells is a well-studied phenomenon for more than 50 years, and it has had a profound impact on the elucidation of the molecular basis of aging [1]. The Hayflick system of serially passaged-related cellular aging and the ultimate replicative senescence has also been widely used to test the effects of various natural and synthetic compounds as modulators of aging and longevity, and as rejuvenators of senescent cells [2][3][4][5].…”

Differential translocation of heat shock factor-1 after mild and severe stress to human skin fibroblasts undergoing aging in vitro

“…However, after about P-40, the growth of FSF-1 cells started to slow down progressively during the subsequent 150 days undergoing 20 more passages, and eventually reaching a permanently growth-arrested state of replicative senescence. Cells in near-senescent state used in this study, had all the well described morphological features, including increased cell size, change of shape from thin, long and spindle-like to flattened and irregular, increased number of vacuoles, highly polymerized actin filaments and disorganized microtubules in the cytoskeleton (Rattan 2012). A frequently used marker for cellular senescence is the senescenceassociated β-galactosidase (Dimri et al 1995), which was also observed to increase from less than 5 % positive cells in early passage cultures to more than 85 % positive cells in late passage cultures (data not shown).…”

“…For experiments and data presentation, cells were considered as young at early passages (up to P-14), which is equivalent to 20 % of lifespan completed, and considered as old or near senescent at late passages (P-50 and above) with >80 % of maximum lifespan completed. Figure 1 shows the longevity curve and the phase-contrast microscopic pictures of early passage (P-8) and late passage (P-58) FSF-1 cells, as a typical Hayflick phenomenon of serial passage-associated cellular aging in vitro (Hayflick and Moorhead 1961;Rattan 2012). For the first 100 days of serial passaging and until P-40, FSF-1 cells proliferated rapidly at a constant rate of about 1 population doubling per 2.5 days.…”