Lecture 24 - Inflammation signalling in skeletal muscle

Question 1

What is acute and chronic imflammation related to

Answer 1

Chronic

Muscle atrophy
Aging
Mets
Myopathies

Acute
Muscle hypertrophy
-exercise

Question 2

What are the class inflammatory response mediators?

Answer 2

Neutrophils, monocytes and macrophages

cytokines and chemokines

Question 3

The satellite cells become activated in response to the presence of _______cells, _______ and _____ factors

they then migrate towards the damaged site. You then get ______, _______and ______of myoblasts to get myofibre regeneration

Answer 3

The satellite cells become activated in response to the presence of immune cells, cytokines and growth factors

they then migrate towards the damaged site. You then get proliferation, differentiation and fusion of myoblasts to get myofibre regeneration

Question 4

What are the initial responses to skeletal muscle injury wrt. inflammatory mediators

Answer 4

Neutrophil levels rise first

then macrophages
then T cells

Question 5

The main time frame for immune cell involvement following a stress insult is..

Answer 5

0-14 days

Question 6

True or false

for complete muscle repair, macrophages NEED to be present

Answer 6

true

Question 7

There is an upregulation of ___ during exercise

what does it exceed?

Answer 7

plasma IL-6

maintained well after exercise and preceeds IL_10, MFP-1

Question 8

What determines the post-exercise plasma IL-6 amplitude?

Answer 8

The number of muscle groups recruited and the intensity/duration

Question 9

What are examples of myokines (mediators released FROM the muscle?)

Answer 9

IL-6, IL-4/15

as well as chemkines like MCP-1

These effect behaviour of other cells and tissues

Question 10

Which myokines are reponsible for

-muscle hypertrophy
Anti-infalmmatory
-pro-inflammatory

Answer 10

-muscle hypertrophy
LIF, !L-4, IL-6, IL-7, IL-15, myostatin

Anti-infalmmatory
IL-6, IL-10

-pro-inflammatory
IL-6, IL-1ra, IL-8

IL- can do all !

Question 11

Through which pathway does IL-6 act?

Answer 11

JAK STAT pathway

Question 12

(look over the JAK/STAT signalling pathway)

Answer 12

now

Question 13

There is a massive upregulation of STAT3 folowing resistance exercise

It is also translocated where?

Answer 13

to the nucleus

Question 14

True or False

STAT 5 is phosphorylated following aerobic and resistance exercise

Answer 14

false

not resistance exercise

STAT5 activation is thought to be because exercise-induced release of GH

Question 15

Which 4 factors influence the inflammatory resposne?

Answer 15

Training status

Aging

Gender

Medications

Question 16

What is the IL-6 response to high-intensity interval training (HIIT)

Answer 16

A single bout will immediately upregulate IL-6

This is NOT altered with successive training bouts

Question 17

True or False

Plasma and muscle derived IL-6 are elevated following exercise, irrespective of training status

Answer 17

true

Question 18

True or False

STAT3 is elevated following exercise, irrespective of training status

Answer 18

true

despite conditioning of the muscle there is still a need for inflammatory signalling to mediate muscle adaption

Question 19

How is cytokine response to eccentric exercise altered with age?

Answer 19

There is less lymphoctye presence in the older person at a basal level

otherwise see the same response to exercise

there does not appears to be an age related difference in the release of white blood cells following exercise

Question 20

True of False

There appears to be a lesser macrophage response to exercise in younger people compared to older

Answer 20

false

There appears to be a greater macrophage response to exercise in younger people compared to older

remember it is needed for muscle repair

Question 21

Plasma IL-6 levels at rest were ____ in elderly vs. young subjects

IL-6 increased in response to exercise in both groups but was higher in _____ compared with _____subjects

Answer 21

Plasma IL-6 levels at rest were elevated in elderly vs. young subjects

IL-6 increased in response to exercise in both groups but was higher in young compared with elderly subjects

Question 22

Upregulation of STAT3 is greater in __ subjects

Answer 22

older

Question 23

What does SOCS3 do?

Answer 23

Negative regulator of STAT3 signalling (and hence IL-6 inhibitor)

Question 24

Exercise induced translation of SOCS3 is dysregulated with ___

Answer 24

age

Question 25

Do females have an elevated initial immune response?

Answer 25

yes

Question 26

Although females have an elevated initial immune response, this is not reflected by the infiltration of ______ 24 hr post exercise

Answer 26

macrophages

Question 27

True of False

There is a difference in circulating IL-6 and STAT3 post exercise between young men and women

Answer 27

false

same with enderly males and females. No difference wrt. IL-6 and MCP-1 following acute exercise

Question 28

true or False

the injection of anti-inflammatory can negatively affect protein synthesis

Answer 28

true

Question 29

Ingestion of anit-inflammatory drugs prior to, during or post exercise can reduce the inflammatory response, has negative effects on _____ __ activation and therefore muscle regeneration

Answer 29

satellite cell