Mechanisms Of Ageing ☺️ Flashcards
When does ageing start
30s - decline in organ and tissue function
What is programmed ageing
Built in programme in the genome that triggers age related changed
- species specific lifespan = relatively constant
- limited cell division/ Hayflick limit (eg fibroblasts, telomeres) => cell senecence which can secrete pro oncotic factors and reduced tissue repair
- fast ageing syndromes (eg progeria) => premature white hair, cancer
No evidence for this but genetic mechanisms counteract build up of damage
What are gerontogenes
Genes that effect lifespan when mutated or expression changed
-often involved in cell repair and regeneration
What is random stochastic damage
Damaged caused by life
- high metabolic rate reduces life due to ROS from environment, lifestyle, inflammation => damage all molecules and organelles => DNA damage
- spontaneous chemical reaction between sugars and proteins increased by ROS => protein aggregates even in food, positive feedback => change in protein structure and function
What are the consequences of AGE accumulation
Stiffening of arteries and weakening of bones
AD
How to slow down the ageing process
Antioxidants
- enzymes - made by our genes
- food - must be replaced but too much can be harmful
What is oxidative stres
Imbalance between antioxidants and oxidants
- we need them to live but too many are harmful
How can calorie restriction slow down ageing
Reduction in calories with complete nutrition
- reduce ROS
- reduce proteotoxicity, AGE, DNA damage
- methylation changes => increased expression on survival response genes
- fall in BP, atherosclerosis
- decreased inflammation
How can exercise slow down ageing
Physical activity cannot stop the decrement alert effect of inherent ageing but can maintain health
Reduces inflammaging and immunosenecence due to increased thymus output
- CHD, MI
- T2DM
- HTN, obesity
