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Cell Jan 2023Aging is driven by hallmarks fulfilling the following three premises: (1) their age-associated manifestation, (2) the acceleration of aging by experimentally... (Review)
Review
Aging is driven by hallmarks fulfilling the following three premises: (1) their age-associated manifestation, (2) the acceleration of aging by experimentally accentuating them, and (3) the opportunity to decelerate, stop, or reverse aging by therapeutic interventions on them. We propose the following twelve hallmarks of aging: genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, disabled macroautophagy, deregulated nutrient-sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, altered intercellular communication, chronic inflammation, and dysbiosis. These hallmarks are interconnected among each other, as well as to the recently proposed hallmarks of health, which include organizational features of spatial compartmentalization, maintenance of homeostasis, and adequate responses to stress.
Topics: Cellular Senescence; Epigenesis, Genetic; Proteostasis; Stem Cells; Aging
PubMed: 36599349
DOI: 10.1016/j.cell.2022.11.001 -
Physiological Reviews Apr 2019Cellular senescence is a permanent state of cell cycle arrest that occurs in proliferating cells subjected to different stresses. Senescence is, therefore, a cellular... (Review)
Review
Cellular senescence is a permanent state of cell cycle arrest that occurs in proliferating cells subjected to different stresses. Senescence is, therefore, a cellular defense mechanism that prevents the cells to acquire an unnecessary damage. The senescent state is accompanied by a failure to re-enter the cell cycle in response to mitogenic stimuli, an enhanced secretory phenotype and resistance to cell death. Senescence takes place in several tissues during different physiological and pathological processes such as tissue remodeling, injury, cancer, and aging. Although senescence is one of the causative processes of aging and it is responsible of aging-related disorders, senescent cells can also play a positive role. In embryogenesis and tissue remodeling, senescent cells are required for the proper development of the embryo and tissue repair. In cancer, senescence works as a potent barrier to prevent tumorigenesis. Therefore, the identification and characterization of key features of senescence, the induction of senescence in cancer cells, or the elimination of senescent cells by pharmacological interventions in aging tissues is gaining consideration in several fields of research. Here, we describe the known key features of senescence, the cell-autonomous, and noncell-autonomous regulators of senescence, and we attempt to discuss the functional role of this fundamental process in different contexts in light of the development of novel therapeutic targets.
Topics: Aging; Animals; Cell Proliferation; Cell Transformation, Neoplastic; Cellular Senescence; Humans; Neoplasms; Wound Healing
PubMed: 30648461
DOI: 10.1152/physrev.00020.2018 -
Ageing Research Reviews Aug 2016Answering the question as to why we age is tantamount to answering the question of what is life itself. There are countless theories as to why and how we age, but, until... (Review)
Review
Answering the question as to why we age is tantamount to answering the question of what is life itself. There are countless theories as to why and how we age, but, until recently, the very definition of aging - senescence - was still uncertain. Here, we summarize the main views of the different models of senescence, with a special emphasis on the biochemical processes that accompany aging. Though inherently complex, aging is characterized by numerous changes that take place at different levels of the biological hierarchy. We therefore explore some of the most relevant changes that take place during aging and, finally, we overview the current status of emergent aging therapies and what the future holds for this field of research. From this multi-dimensional approach, it becomes clear that an integrative approach that couples aging research with systems biology, capable of providing novel insights into how and why we age, is necessary.
Topics: Aging; Animals; Forecasting; Free Radical Scavengers; Humans; Reactive Oxygen Species; Stem Cell Transplantation
PubMed: 27353257
DOI: 10.1016/j.arr.2016.06.005 -
Nature Nov 2016Although systemic diseases take the biggest toll on human health and well-being, increasingly, a failing brain is the arbiter of a death preceded by a gradual loss of... (Review)
Review
Although systemic diseases take the biggest toll on human health and well-being, increasingly, a failing brain is the arbiter of a death preceded by a gradual loss of the essence of being. Ageing, which is fundamental to neurodegeneration and dementia, affects every organ in the body and seems to be encoded partly in a blood-based signature. Indeed, factors in the circulation have been shown to modulate ageing and to rejuvenate numerous organs, including the brain. The discovery of such factors, the identification of their origins and a deeper understanding of their functions is ushering in a new era in ageing and dementia research.
Topics: Aging; Animals; Brain; Cell Communication; Humans; Inflammation; Neurodegenerative Diseases; Proteome; Rejuvenation
PubMed: 27830812
DOI: 10.1038/nature20411 -
Cardiovascular Research Mar 2022Cellular senescence is a state of irreversible cell cycle arrest associated with ageing. Senescence of different cardiac cell types can direct the pathophysiology of... (Review)
Review
Cellular senescence is a state of irreversible cell cycle arrest associated with ageing. Senescence of different cardiac cell types can direct the pathophysiology of cardiovascular diseases (CVDs) such as atherosclerosis, myocardial infarction, and cardiac fibrosis. While age-related telomere shortening represents a major cause of replicative senescence, the senescent state can also be induced by oxidative stress, metabolic dysfunction, and epigenetic regulation, among other stressors. It is critical that we understand the molecular pathways that lead to cellular senescence and the consequences of cellular senescence in order to develop new therapeutic approaches to treat CVD. In this review, we discuss molecular mechanisms of cellular senescence, explore how cellular senescence of different cardiac cell types (including cardiomyocytes, cardiac endothelial cells, cardiac fibroblasts, vascular smooth muscle cells, and valve interstitial cells) can lead to CVD, and highlight potential therapeutic approaches that target molecular mechanisms of cellular senescence to prevent or treat CVD.
Topics: Aging; Cardiovascular Diseases; Cellular Senescence; Endothelial Cells; Epigenesis, Genetic; Humans; Myocytes, Cardiac
PubMed: 33963378
DOI: 10.1093/cvr/cvab161 -
Nature Jul 2019For several decades, understanding ageing and the processes that limit lifespan have challenged biologists. Thirty years ago, the biology of ageing gained unprecedented... (Review)
Review
For several decades, understanding ageing and the processes that limit lifespan have challenged biologists. Thirty years ago, the biology of ageing gained unprecedented scientific credibility through the identification of gene variants that extend the lifespan of multicellular model organisms. Here we summarize the milestones that mark this scientific triumph, discuss different ageing pathways and processes, and suggest that ageing research is entering a new era that has unique medical, commercial and societal implications. We argue that this era marks an inflection point, not only in ageing research but also for all biological research that affects the human healthspan.
Topics: Aging; Biomedical Research; Circadian Clocks; Clinical Trials as Topic; Healthy Aging; Humans; Inflammation; Longevity; Mitochondria; Nutritional Status; Oxidative Stress; Rejuvenation; Signal Transduction
PubMed: 31292558
DOI: 10.1038/s41586-019-1365-2 -
Nature Reviews. Immunology Feb 2023Genomic instability is an important driver of ageing. The accumulation of DNA damage is believed to contribute to ageing by inducing cell death, senescence and tissue... (Review)
Review
Genomic instability is an important driver of ageing. The accumulation of DNA damage is believed to contribute to ageing by inducing cell death, senescence and tissue dysfunction. However, emerging evidence shows that inflammation is another major consequence of DNA damage. Inflammation is a hallmark of ageing and the driver of multiple age-related diseases. Here, we review the evidence linking DNA damage, inflammation and ageing, highlighting how premature ageing syndromes are associated with inflammation. We discuss the mechanisms by which DNA damage induces inflammation, such as through activation of the cGAS-STING axis and NF-κB activation by ATM. The triggers for activation of these signalling cascades are the age-related accumulation of DNA damage, activation of transposons, cellular senescence and the accumulation of persistent R-loops. We also discuss how epigenetic changes triggered by DNA damage can lead to inflammation and ageing via redistribution of heterochromatin factors. Finally, we discuss potential interventions against age-related inflammation.
Topics: Humans; DNA Damage; Aging; Cellular Senescence; Inflammation; Cell Death
PubMed: 35831609
DOI: 10.1038/s41577-022-00751-y -
Nature Jun 2021Ageing of the immune system, or immunosenescence, contributes to the morbidity and mortality of the elderly. To define the contribution of immune system ageing to...
Ageing of the immune system, or immunosenescence, contributes to the morbidity and mortality of the elderly. To define the contribution of immune system ageing to organism ageing, here we selectively deleted Ercc1, which encodes a crucial DNA repair protein, in mouse haematopoietic cells to increase the burden of endogenous DNA damage and thereby senescence in the immune system only. We show that Vav-iCre;Ercc1 mice were healthy into adulthood, then displayed premature onset of immunosenescence characterized by attrition and senescence of specific immune cell populations and impaired immune function, similar to changes that occur during ageing in wild-type mice. Notably, non-lymphoid organs also showed increased senescence and damage, which suggests that senescent, aged immune cells can promote systemic ageing. The transplantation of splenocytes from Vav-iCre;Ercc1 or aged wild-type mice into young mice induced senescence in trans, whereas the transplantation of young immune cells attenuated senescence. The treatment of Vav-iCre;Ercc1 mice with rapamycin reduced markers of senescence in immune cells and improved immune function. These data demonstrate that an aged, senescent immune system has a causal role in driving systemic ageing and therefore represents a key therapeutic target to extend healthy ageing.
Topics: Aging; Animals; DNA Damage; DNA Repair; DNA-Binding Proteins; Endonucleases; Female; Healthy Aging; Homeostasis; Immune System; Immunosenescence; Male; Mice; Organ Specificity; Rejuvenation; Sirolimus; Spleen
PubMed: 33981041
DOI: 10.1038/s41586-021-03547-7 -
Mechanisms of Ageing and Development Sep 2021The skin is comprised of different cell types with different proliferative capacities. Skin aging occurs with chronological age and upon exposure to extrinsic factors... (Review)
Review
The skin is comprised of different cell types with different proliferative capacities. Skin aging occurs with chronological age and upon exposure to extrinsic factors such as photodamage. During aging, senescent cells accumulate in different compartments of the human skin, leading to impaired skin physiology. Diverse skin cell types may respond differently to senescence-inducing stimuli and it is not clear how this results in aging-associated skin phenotypes and pathologies. This review aims to examine and provide an overview of current evidence of cellular senescence in the skin. We will focus on cellular characteristics and behaviour of different skin cell types undergoing senescence in the epidermis and dermis, with a particular focus on the complex interplay between mitochondrial dysfunction, autophagy and DNA damage pathways. We will also examine how the dermis and epidermis cope with the accumulation of DNA damage during aging.
Topics: Aging; Autophagy; Cellular Senescence; DNA Damage; Humans; Mitochondria; Skin; Skin Aging
PubMed: 34166688
DOI: 10.1016/j.mad.2021.111525 -
Physiological Research Sep 2020Ageing is accompanied by deterioration in physical condition and a number of physiological processes and thus a higher risk of a range of diseases and disorders. In... (Review)
Review
Ageing is accompanied by deterioration in physical condition and a number of physiological processes and thus a higher risk of a range of diseases and disorders. In particular, we focused on the changes associated with aging, especially the role of small molecules, their role in physiological and pathophysiological processes and potential treatment options. Our previously published results and data from other authors lead to the conclusion that these unwanted changes are mainly linked to the hypothalamic-pituitary-adrenal axis can be slowed down, stopped, or in some cases even reversed by an appropriate treatment, but especially by a life-management adjustment.
Topics: Aging; Animals; Hormones; Humans; Hypothalamo-Hypophyseal System; Pituitary-Adrenal System; Receptors, Cell Surface; Small Molecule Libraries
PubMed: 33094624
DOI: 10.33549/physiolres.934523