Lecture 24 - Inflammation signalling in skeletal muscle Flashcards
What is acute and chronic imflammation related to
Chronic
Muscle atrophy
Aging
Mets
Myopathies
Acute
Muscle hypertrophy
-exercise
What are the class inflammatory response mediators?
Neutrophils, monocytes and macrophages
cytokines and chemokines
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
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
What are the initial responses to skeletal muscle injury wrt. inflammatory mediators
Neutrophil levels rise first
then macrophages
then T cells
The main time frame for immune cell involvement following a stress insult is..
0-14 days
True or false
for complete muscle repair, macrophages NEED to be present
true
There is an upregulation of ___ during exercise
what does it exceed?
plasma IL-6
maintained well after exercise and preceeds IL_10, MFP-1
What determines the post-exercise plasma IL-6 amplitude?
The number of muscle groups recruited and the intensity/duration
What are examples of myokines (mediators released FROM the muscle?)
IL-6, IL-4/15
as well as chemkines like MCP-1
These effect behaviour of other cells and tissues
Which myokines are reponsible for
-muscle hypertrophy
Anti-infalmmatory
-pro-inflammatory
-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 !
Through which pathway does IL-6 act?
JAK STAT pathway
(look over the JAK/STAT signalling pathway)
now
There is a massive upregulation of STAT3 folowing resistance exercise
It is also translocated where?
to the nucleus
True or False
STAT 5 is phosphorylated following aerobic and resistance exercise
false
not resistance exercise
STAT5 activation is thought to be because exercise-induced release of GH
Which 4 factors influence the inflammatory resposne?
Training status
Aging
Gender
Medications
What is the IL-6 response to high-intensity interval training (HIIT)
A single bout will immediately upregulate IL-6
This is NOT altered with successive training bouts
True or False
Plasma and muscle derived IL-6 are elevated following exercise, irrespective of training status
true
True or False
STAT3 is elevated following exercise, irrespective of training status
true
despite conditioning of the muscle there is still a need for inflammatory signalling to mediate muscle adaption
How is cytokine response to eccentric exercise altered with age?
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
True of False
There appears to be a lesser macrophage response to exercise in younger people compared to older
false
There appears to be a greater macrophage response to exercise in younger people compared to older
remember it is needed for muscle repair
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
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
Upregulation of STAT3 is greater in __ subjects
older
What does SOCS3 do?
Negative regulator of STAT3 signalling (and hence IL-6 inhibitor)
Exercise induced translation of SOCS3 is dysregulated with ___
age
Do females have an elevated initial immune response?
yes
Although females have an elevated initial immune response, this is not reflected by the infiltration of ______ 24 hr post exercise
macrophages
True of False
There is a difference in circulating IL-6 and STAT3 post exercise between young men and women
false
same with enderly males and females. No difference wrt. IL-6 and MCP-1 following acute exercise
true or False
the injection of anti-inflammatory can negatively affect protein synthesis
true
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
satellite cell
