HBIO320 MYOKINES EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS GRADED A++
Myokines involved in mTOR Pathway (Resistance Training; Protein Synthesis)
- decreased myostatin
- increased folistatin
- increased decorin
- FGF21
- (some) meteorin-like
Myokines involved in AMPK Pathway (Endurance Training; Mitochondrial
Biogenesis)
- increased PGC-1ɑ (not a myokine)
- increases irisin
- increased meteorin-like
- increased IL-6
- increased BDNF
Interleukin 6 (IL-6)
- decreases insulin sensitivity when released by adipose monocytes (ubiquitination of
Insulin Receptor Substrate-1)
- increases sensitivity when released by muscle
- stimulates GLUT-4 accumulation (muscle)
IL-6 Pathway to Decrease Insulin Sensitivity
, 1. IL-6 on GP130 Receptor
2. Activate JAK (kinase) activates STAT3
3. SOCS3 is active
- negative feedback for JAK
- Ubiquitination of IRS1 (protetolysis)
4. AKT cannot be activated to induce more GLUT4 production
What are the transcription factors for IL-6 production from adipose and muscle
cells?
Adipose = NFkB
Muscle = AP-1
Stimulants of IL-6
- increased intracellular calcium
- lactate
- ROS
- glycogen depletion
Function of IL-6
- increase lipolysis and gluconeogenesis
- increase glucose uptake and fat oxidation in muscle (works with previous point)
- stimulate satellite cell proliferation
- induces hypertrophy of new muscle cells (not like resistance training)
Myostatin stimulant and inhibitor
- reduced with resistance exercise
- increases with glucocorticoids/cortisol
WITH COMPLETE SOLUTIONS GRADED A++
Myokines involved in mTOR Pathway (Resistance Training; Protein Synthesis)
- decreased myostatin
- increased folistatin
- increased decorin
- FGF21
- (some) meteorin-like
Myokines involved in AMPK Pathway (Endurance Training; Mitochondrial
Biogenesis)
- increased PGC-1ɑ (not a myokine)
- increases irisin
- increased meteorin-like
- increased IL-6
- increased BDNF
Interleukin 6 (IL-6)
- decreases insulin sensitivity when released by adipose monocytes (ubiquitination of
Insulin Receptor Substrate-1)
- increases sensitivity when released by muscle
- stimulates GLUT-4 accumulation (muscle)
IL-6 Pathway to Decrease Insulin Sensitivity
, 1. IL-6 on GP130 Receptor
2. Activate JAK (kinase) activates STAT3
3. SOCS3 is active
- negative feedback for JAK
- Ubiquitination of IRS1 (protetolysis)
4. AKT cannot be activated to induce more GLUT4 production
What are the transcription factors for IL-6 production from adipose and muscle
cells?
Adipose = NFkB
Muscle = AP-1
Stimulants of IL-6
- increased intracellular calcium
- lactate
- ROS
- glycogen depletion
Function of IL-6
- increase lipolysis and gluconeogenesis
- increase glucose uptake and fat oxidation in muscle (works with previous point)
- stimulate satellite cell proliferation
- induces hypertrophy of new muscle cells (not like resistance training)
Myostatin stimulant and inhibitor
- reduced with resistance exercise
- increases with glucocorticoids/cortisol
