Cellular senescence: beneficial, harmful, and highly complex

Abstract

The contribution of cellular senescence to a diverse range of biological processes, including normal physiology, ageing, and pathology were long overlooked but have now taken centre stage. In this Editorial, we will briefly outline the review and original work articles contained in The FEBS Journal's Special Issue on Senescence in Ageing and Disease. It is beginning to be appreciated that senescent cells can exert both beneficial and adverse effects following tissue injury. Additionally, while these cells play critical roles for maintaining a healthy physiology, they also promote ageing and certain pathological conditions (including developmental disorders). Progress has been made in re‐defining and identifying senescent cells, especially in slow‐proliferating or terminally differentiated tissues, such as the brain and cardiovascular system. Novel approaches and techniques for isolating senescent cells will greatly increase our appreciation for senescent properties in tissues. The inter‐organ communication between senescent cells and other residents of the tissue microenvironment, via the senescence‐associated secretory phenotype (SASP), is a focus of several reviews in this Special Issue. The importance of the SASP in promoting tumour development and the evolution of SARS CoV‐2 variants is also highlighted. In one of the two original articles included in the issue, the impact of dietary macronutrients and the presence of senescent cells in mice is investigated. Lastly, we continue to deepen our understanding on the use of senolytics and senomorphics to specifically target senescent cells or their secreted components, respectively, which is discussed in several of the reviews included here.

The interaction between ageing and Alzheimer's disease: insights from the hallmarks of ageing

“…Microglia in patients with AD also exhibit an ageing phenotype [ 175 ]. As SASP factors are composed of various pro-inflammatory factors including cytokines, growth factors, angiogenic factors and soluble proteins, as well as extracellular vesicles [ 176 ], it is difficult to distinguish between the inflammatory activation state and the ageing state of inflammatory cell types such as microglia. The phagocytic function of microglia is usually enhanced at an inflammatory activation state [ 177 ] while substantially reduced at the ageing state.…”

The FEBS Journal in 2024: maintaining standards and taking the road less travelled

“…During 2023, we published a Special Issue on 'Senescence in Ageing and Disease' (Fig. 2) edited by Editorial Board member Pura Muñoz-C anoves [14] and a Focus Issue on 'Enzymology' (Fig. 3), introduced by Editorial Board member Nigel Scrutton [15].…”

Back to the Basics: Usefulness of Naturally Aged Mouse Models and Immunohistochemical and Quantitative Morphologic Methods in Studying Mechanisms of Lung Aging and Associated Diseases

“…Cellular senescence is a state of irreversible proliferative arrest that presents after a discrete number of cell divisions, whose underlying cause is telomere uncapping triggered by the continuous loss of telomere sequences during cell division. A senescent phenotype can occur due to different stimuli, including injury, ROS, irradiation, and nutrient imbalances [34,35]. The impact of cellular senescence on the aging process in an organismic context is not entirely clear, mainly due to the paucity of data on the frequency of senescent cells in tissues during the aging process.…”