Aging HyoungJinChoi 2024 Geromics Course

Definition 

Ageing (or aging in American English) is the process of becoming older. The term refers mainly to humans, many other animals, and fungi, whereas for example, bacteria, perennial plants and some simple animals are potentially biologically immortal.^[1] In a broader sense, ageing can refer to single cells within an organism which have ceased dividing, or to the population of a species.^[2]

In humans, ageing represents the accumulation of changes in a human being over time and can encompass physical, psychological, and social changes.^[3][4] Reaction time, for example, may slow with age, while memories and general knowledge typically increase. Ageing is associated with increased risk of cancer, Alzheimer's disease, diabetes, cardiovascular disease and many more.^[5][6] Of the roughly 150,000 people who die each day across the globe, about two-thirds die from age-related causes.

Current ageing theories are assigned to the damage concept, whereby the accumulation of damage (such as DNA oxidation) may cause biological systems to fail, or to the programmed ageing concept, whereby the internal processes (epigenetic maintenance such as DNA methylation)^[7][8] inherently may cause ageing. Programmed ageing should not be confused with programmed cell death (apoptosis).

Obesity has been proposed to accelerate ageing,^[9][10] whereas dietary calorie restriction in non-primate animals slows ageing while maintaining good health and body functions. In primates (including humans), such life-extending effects remain uncertain.

full text link 
 

 

Paper review

1) Hallmarkers of aging : An expanding universe

Summary

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.

in detail ​twelve hallmarks:
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
dysbiosis


link : https://www.cell.com/cell/fulltext/S0092-8674(22)01377-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867422013770%3Fshowall%3Dtrue