Neuropathology Flashcards
What is a Lysosome
“Digestive system” of cell. Small membrane-bound organelles containing hydrolases that degrade macromolecules arriving by endocytosis, phagocytosis or autophagy
What’s the difference between phagocytosis and pinocytosis?
Phagocytosis is the cytosis of a solid particle whereas pinocytosis deals with (extracellular) fluids
What’s the difference between a phago/pinocytosed vesicle and receptor-mediated endocytosed vesicle
Receptor-mediated endocytosed vesicles have coat proteins on the outside becoming a coated vesicle
What is the name of a phagocytosed particle engulfed in a vesicle
Phagosome (cytosome)
What is an autophagosome
?
What gets packaged in vesicles
Damaged organelles, lipids, denatured proteins (happens around pH 6)
What happens to lysosomes in the rER before they’re finally packaged
They’re fly soulmates and tagged with mannose-6-phosphate ligand which allows the package to be easily picked up by cells with mannose-6-phosphate receptors
How many enzymes does a lysosome contain
Over 50
Brief description of what happens if lysosomes lose function
Accumulation of substrate that’s meant to be broken down. This can affect the brain, bones, muscles etc.
How many lysosomal storage disorders are there
Over 50
What does MPS disease stand for
MucoPolySaccharide Disease
What is the cause of Mucopolysaccharide disease
Caused by enzymatic defect in the breakdown glycosaminoglycans (long chain sugars) —> different GAG sugars being stored
What happens in MPS that causes the storage of Heparin Sulphide?
exhibit lysosomal swelling l, neuroinflammation, sever brain dysfunction and behavioural problems.
What’s the name for MPS type 1
Hurler’s syndrome
What is hurlers syndrome
An autosomal recessive disease resulting in progress neurodegeneration. Some treatments are available through HSCT and ERT
What are some symptoms of Hurlers syndrome (MPS Type 1)
Cloudy corneas, deafness, intellectual disability, halted growth, bone and joint problems
What’s the name MPS type 3
Sanfilippo disease
Characteristics for MPS Type 3
Sanfilippo disease affects the first decade of life, leads to death in adolescence and progressive cognitive function & latter mother decline.
Stores heparin sulphide and also secondary storage if GM gangliosides
What can the storage of GAG sugars lead to
Lysosomal swelling and dysfunction. Can be leaked into bloodstream to cause problems for immune system
There is a natural multi step process of heparin degradation. What happens if one of these steps/enzymes is disrupted
Accumulation of HS over time leading to storage of GAGs
How can the sulphation heparin sulphide be monitored
Disaccharide analysis
What do we see in the neuropathology if lysosomal disorder
Enlarged lysosomal compartment due to lysosomal swelling
What can MPS disease lead to the secondary storage of
GM2 ganglioside
What other organelle may we see under the microscope when looking at neuronflamation
Microglia - proliferate to deal with presence (Depredation) of GAGs - sort of like macrophages