Flashcards
Ageing - sarcopenia
Flashcards do conjunto (9)
- 1What is sarcopenialoss of skeletal muscle mass and strength with ageing
- 2What factors cause sarcopeniaReduced stem cell function - reduced number, failure to respond, poor potential
Neuro-degeneration - lack of innervation results in increased atrophy of muscle fibres, the proportion of fibres in contact with motor neurons decreases with age
Disuse - lack of physical activity
Sub-optimal nutrition/ malabsorption
Age-related apoptosis
Age-related mitochondrial dysfunction
Hormonal factors
Inflammatory cytokines - lead to a decrease in motor fibre number and size - 3How can one preserve muscle stem cell functionprotein synthesis
reduced degradation - 4How does activity affect sarcopeniaMinimises the extent of sarcopenia in later life
resistance training increases muscle fibre innervation (maintains neuromuscular junctions better), improves muscle fibre recruitment, increases protein synthesis and increases the number of satellite cells, leading to faster muscle regeneration - 5Give possible reasons for the reduced satellite cell capacity for regenerationIncreased p16 (tumour supressor) expression with age prevents satellite cell activation and self-renewal
- 6What study can be carried out to investigate the significance of the stem cell niche on sarcopenia? What were the conclusions?Rejuvenation of aged progenitor cells by exposure to a young systemic environment
• I M Conway, 2005
• Parabiotic mice – share blood supply
• OO, YY, OY
• OY – old could repair itself better
• Young mouse had poorer muscle regeneration
• Suggests that there are serum factors involved in sarcopenia - 7How is the progeria mouse model used to show accelerated ageingIn ageing there is increased fibrosis
decreased muscle fubre size
increased abnormalities in the neuromuscular junctions (where the nerve terminal connects to the end plate) - 8What constitutes the satellite cell nichesatellite cell located between the basal lamina and the plasma membrane
- 9How does the aged niche disrupt satellite cell quiescenceIncreases FGF signalling (therefore increased p38 MAPK signallng)
unnecessarily activates SCs
they reach their limited proliferation potential sooner
Levels of FGF inhibitor sprouty 1 decreases with age
Geriatric SCs undergo quiescence-to-senescence switch
Informações
- Descrição
- BSc Enemy within FlashCards sobre Ageing - sarcopenia, criado por Teresa Richards em 24-03-2016.
- Criado por
- Teresa Richards
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