Ch. 24 Aging & Senescence Flashcards Preview

cell phys final > Ch. 24 Aging & Senescence > Flashcards

Flashcards in Ch. 24 Aging & Senescence Deck (10):
1

•Accumulation of DNA damage throughout life
•Loss of DNA repair mechanisms accelerate aging

Genomic instability

2

Lack of telomerase

Shorter telomeres are associated with increased mortality at young age

Telomere Attrition

3

Chromatin remodeling
•Heterochromatin formation

mRNA miRNA

Epigenetic alterations

4

Decreased synthesis of chaperone proteins

Protein degradation (lysosome & proteasome) decrease with age

Loss of protein homeostasis

5

Anabolic pathways

dietary restriction

Sirtuins signal nutrient scarcity & promote cell survival & catabolism
Lopez

Deregulated nutrient sensing

6

•May stimulate proliferative & survival signals
•Less efficient at generating ATP as we age
TOXINS

Mitochondrial dysfunction

7

•Decreased in hematopoiesis with age
•Cell cycles decrease in stem cells in aged
•Due to more DNA damage & overexpression of INK4A (cyclin inhibitor)

Stem cell exhaustion

8

Increase in inflammation (AKA ‘inflammaging’)
•Enhanced activation of NF-kB, senescent cells produce more inflammatory cytokines,

Altered intracellular communication

9

Senescent cells do not re-enter growth cycle

Still metabolically active, just do not replicate any more

Cellular Senescence

10

inflammatory cytokines

Elevated cytokines

liver disease, degenerative disc disease, cancer

Senescence & Disease