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Printable Handouts
Navigable Slide Index
- Introduction
- Overview
- Intracellular signaling in mitochondrial biogenesis
- Calcium signaling
- CaMKIV increases mitochondrial biogenesis
- PGC-1alpha regulates muscle phenotype
- How does PGC-1alpha work?
- PGC-1alpha expression
- PGC-1alpha and exercise
- PGC-1alpha during exercise
- Signaling in mitochondrial biogenesis: AMPK
- Signaling to PGC-1: evidence for AMP kinase
- AMPK Regulates biogenesis via transcription?
- What Regulates the expression of PGC-1alpha?
- Effect of AICAR on PGC-1alpha transcription
- Summary: regulation of PGC-1alpha expression
- Overview of mitochondrial assembly
- Import of nuclear-encoded proteins
- Import into IMF and SS mitochondria
- Activity-induced changes in protein import
- Reduced protein import to disused muscles
- Answers from an unusual line of inquiry
- Altered morphology in Bax-Bak DKO mice
- Effect of exercise on Bax/Bak protein import
- Exercise rescues a protein import defect
- What happens with age in human muscle?
- Indices of mitochondrial content with age
- COX activity increased in young and old animals
- Lysosomal dysfunction & lipofuscin
- Mitochondrial life cycle in muscle disuse
- Exercise to the rescue!
- Lysosomal vs. mitochondrial adaptations
- “Exercise is mitochondrial medicine”
- References
Topics Covered
- Calcium signaling in mitochondrial biogenesis
- The role of PGC-1alpha
- PGC-1alpha expression and exercise
- Regulators of the expression of PGC-1alpha
- Overview of mitochondrial assembly
- Overview of mitochondrial assembly
- Activity-induced changes in protein import
- Aging muscle and exercise adaptations
- The mitochondrial life cycle
- Lysosomal adaptations
- Exercise is mitochondrial medicine
Talk Citation
Hood, D. (2018, May 31). Exercise-induced mitochondrial biogenesis in muscle 2 [Video file]. In The Biomedical & Life Sciences Collection, Henry Stewart Talks. Retrieved December 7, 2024, from https://doi.org/10.69645/LXIH8755.Export Citation (RIS)
Publication History
Financial Disclosures
- Professor David Hood has no commercial/financial relationships to disclose
Exercise-induced mitochondrial biogenesis in muscle 2
Published on May 31, 2018
37 min
A selection of talks on Cell Biology
Transcript
Please wait while the transcript is being prepared...
0:00
My name is David Hood and I'm a professor at York University in Toronto.
I'm the Director of the Muscle Health Research Center,
a center with 22 scientists that study muscle.
Today, I'm going to talk about mitochondrial biogenesis in muscle, part two.
0:20
The topics that we'll discuss include
the signalling and mechanisms involved in mitochondrial biogenesis in muscle,
the protein import pathway as
an important component of how mitochondrial reticulum is assembled,
and end the discussion with how aging muscle,
mitochondria respond to exercise.
0:46
We know for some time now,
that there are basically
three intracellular signals that lead to the production of more mitochondria,
which we call mitochondria biogenesis.
So, this image is of a cartoon of a muscle fiber.
You can see the neuromuscular junction leads to
activation of the muscle calcium release from the sarcoplamic reticulum.
That acts as one of the signals.
Calcium activating kinases, like CaM kinase that will affect
transcription of the genes and it's gene transcription that leads to more mRNA.
The mRNA is translated in the cytosol and the proteins are made.
Some of those proteins will return back to the nucleus,
to act as transcription factor,
but others will enter the mitochondrion through a sophisticated protein import machinery.
That contributes to the biogenesis of
mitochondria as we'll say more about in a few minutes.
When muscle contracts in response to an electrical impulse at the neuromuscular junction,
we get depolarization who break down ATP, ATP to ADP,
some of that ADP is converted to AMP,
and that activates AMP kinase,
which is the second signalling kinase which can also impact transcription.
So, calcium is one signal,
AMP kinase activation is a second signal.
The third signal is the production of reactive oxygen species,
or ROS in this image,
which can come from mitochondria,
come from other reactive oxygen species, enzymes as well.
Those reactive oxygen species also act as
a third signal that leads to transcription in the nucleus
to affect a number of mitochondrial proteins that in
turn influences mitochondrial content in the muscle.
Those are the three signals we believe respond to exercise.
I'll show you some evidence for each of the two signals calcium
first and then AMP kinase activation in subsequent slides.