Lecture #5 Flashcards
can exosomes engulf a whole mitochondria?
no - only in fragments
what are some components of the mitochondria that are highly immunogenic?
- the inner membrane lipid cardiolipin
- the cytochrome C
- mitochondrial DNA
what are all three immunogenic components of mitochondria recognized as?
DAMPS - damage associated molecular patterns
what is transmitophagy?
the process in which neurons deliver damaged mitochondria to astrocytes
when does transmitophagy occur?
when the load is excessive in the neurons and they can’t manage to degrade all the damaged mitochondria
what happens when the CNS releases DAMPs?
these molecules are taken up by microglial cells → macrophages of the CNS
what is the effect of microglial cells releasing DAMPs?
further neuron damage - associated with chronic inflammation
when might microglial cells release entire mitochondria?
if they are damaged
describe neurons:
polarized cells with extreme morphology
what characteristic of mitochondria is crucial for their function?
their need for rejuvenation (proper turnover)
what is mitostasis?
a specialized form of homeostasis by which the mitochondria number and quantity are maintained over time
what are the two levels of mitochondrial control that encompass mitostasis?
molecular (control of the proteome) and organellar (control of mitochondrial dynamics)
what are the player of fusion and fission that are dynamin-like GTPases?
- DRP1
- MFN1 & 2
- OPA1
what are the two types of transport in neurons?
long range and short range
what type of transport occurs in the axons?
long range transport
what is long range transport based on?
based on microtubules and molecular motors that can mediate the anterograde transport and retrograde transport of mit
how does long range transport compare to short range transport?
LRT is much faster
what is short range transport based on?
based on microfilaments of actin or neurofilaments → mit are bound on the cytoskeleton by different motor proteins
why do we need fast transport in axons?
we have to deliver the mit far to synapses
how is speed affected when mitochondria shift from the microtubules to the actin or neurofilament?
the movement becomes slow because the mit need to stay there for a long time in order to provide the ATP to buffer the calcium locally
what is the best form for mitochondria to be transported?
it needs to be in the intermediate state → not completely fragmented but with short tubules
what is the effect on transportation if there are issues with mit fission?
if we lose fission the mitochondria are more elongated, and they can generate giant balloons difficult to transport
what happens when mitochondria are highly fragmented?
there is not transport
what are two crucial events important to neurons played by mitochondria?
ATP production and Ca2+ buffering