Blood brain barrier Flashcards
(45 cards)
BBB consist of
1. _____________ cells lining the capillary wall with _______ _____ between them
2. _______________ of astrocytes abutting on the capillaries as perivascular end-feet.
3.a _________ basement membrane
4.__________
- ENDOTHELIAL cells lining the capillary wall with TIGHT JUNCTIONS between them
- PROCESSES of astrocytes abutting on the capillaries as perivascular end-feet.
3.a CAPILLARY basement membrane
4.PERICYTES
The function of ________________ (BBB) is specialized system of brain _____________ endothelial cell (BMVEC) that shields the brain from __________ substances in the blood, _______ brain tissues with _________, and ________ harmful compounds from the brain back to the bloodstream.
The blood-brain barrier (BBB) is the specialized system of brain microvascular endothelial cells (BMVEC) that shields the brain from toxic substances in the blood, supplies brain tissues with nutrients, and filters harmful compounds from the brain back to the bloodstream.
Proportions of the blood-brain barrier
1.____________and ___________
2.
Note that _______ with a diameter of ________nm
Other components of the _______________ unit are indicated.
Proportions of the blood-brain barrier
1.capillary lumen and walls
2. basement membrane
Note that albumin with a diameter of 7 nm
Other components of the neurovascular unit are indicated.
BBB- Nuerovascular Unit consist of :
1.
2.
.3
.4.
5.
6.
7.
8.
BBB- Nuerovascular Unit consist of :
1. Endothelial cell
2.Pericyte
3. Astrocyte End feet
4. Interneuron
5. Neuron
6. Astrocyte
7.Basement membrane
8. Microglia
Confocal image shows elements of the neurovascular unit in the ____________. An _______ consisting of ___________-,_______________ and modified _______________ cell layers is surrounded by _____________ processes. Some of the ____________ processes in the surrounding __________ are in close proximity to the ____________ astrocytes and the vessel wall.
Confocal image shows elements of the neurovascular unit in the cerebral cortex. An arteriole consisting of endothelial, smooth muscle, and modified leptomeningeal cell layers is surrounded by astrocytic processes (red). Some of the
neuronal processes (green) in the surrounding neuropil are in close proximity to the perivascular astrocytes and the vessel wall.
Anatomy of the BBB
1.
2.
3.
4.
5.
6.
7.
- Neuron
- Basal lamina
- Endothelial cell
- Lumen
- Tight junction
6.Pericyte
7.Astrocyte feet
The ________________ (BM) is a sheet-like (ECM) extracellular matrix complex ___________ epithelium and endothelium.
The basement membrane (BM) is a sheet-like (ECM) extracellular matrix complex beneath epithelium and endothelium.
At the BBB the BM encircles the ______________ side of the ____________ and is located at the interface of the circulation system and central nervous system.
At the BBB, the BM encircles the abluminal side of blood vessels and is located at the interface of the circulation system and central nervous system.
Brain BM consists of 5 major proteins:
1.
2.
3.
4.
5.
1.collagen IV*
2. laminin
3. nidogen
4. perlecan*
5. agrin*****
_________________________ have many properties which are similar to those present in _______________________ including the expression of ___________________, ___________ molecules and __________ receptors.
Brain endothelial cells have many properties which are similar to those present in nonneural endothelium including the expression of glycoproteins, adhesion molecules, and integrin receptors.
The principal morphological features which distinguish the endothelial cells of _______________ vessels from those of ____________ vessels and form the structural basis of the BBB to proteins include reduced density of _______________ and the presence of circumferential _______________ between endothelial cells.
The principal morphological features which distinguish the endothelial cells of intracerebral vessels from those of nonneural vessels and form the structural basis of the BBB to proteins include reduced density of caveolae and the presence of circumferential tight junctions between endothelial cells.
Brain endothelial cells also have increased density of ____________________.
Brain endothelial cells also have increased density of mitochondria.
A wide range of ____________________ molecules can diffuse through the endothelium and enter brain ______________.
A wide range of lipid-soluble molecules can diffuse through the endothelium and enter brain passively.
_________, which carry a positive charge, have an advantage over __________ in penetration of endothelial cells and it is probably the cationic nature of these molecules and an interaction with the negatively charged_________________ and phospholipid head groups of the outer leaflet of the cell membrane that facilitates their entry.
Bases, which carry a positive charge, have an advantage over acids in penetration of endothelial cells and it is probably the cationic nature of these molecules and an interaction with the negatively charged glycocalyx and phospholipid head groups of the outer leaflet of the cell membrane that facilitates their entry.
____________________ ___________________ transport across cerebral endothelium occurs by:
1.
2.
3.
4.
5.
Transcellular bidirectional transport across cerebral endothelium occurs by:
1. receptor-mediated transport
2.carrier-mediated transport
3. ion transport
4.peptide transport
5. active efflux transport.
____________ transport systems facilitate transport of nutrients into brain including:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Carrier-mediated transport systems facilitate transport of nutrients into brain including:
hexoses (glucose, galactose)
neutral, basic and acidic amino acids
monocarboxylic acids (lactate, pyruvate, ketone bodies) nucleosides
(adenosine, guanosine, uridine)
purines (adenine, guanine)
nucleotides
nucleobases
organic anion, and organic cations
amine
vitamins.
Endothelial cells tight junctions:
1 CELL:
1. Claudins (pegada al terminal ___ y _____ intracelular)+ _________
2.Occludin (pegada al terminal ____ y _____ intracelular)+ ________
3. JAMs (pegada al terminal _____ y el _____ se encuentra + extraceullar) + ___________
2 CELL:
1.En el terminal ____ esta pegado ZO-___ (L-cingulin y R-actin)
2. En el terminal _____ esta pegado ZO-___ (actin) y en el ________ esta MUPP1, parece estar pegado también con ZO-_____.
3.En el terminal ______ esta ZO-____ (actin) pegado con MAGIs.
1 CELL:
1. Claudins (pegada al terminal N y C intracelular)+ apicales
2.Occludin (pegada al terminal C y N intracelular)+ medial
3. JAMs (pegada al terminal C y el N se encuentra + extraceullar) + basal
2 CELL:
1.En el terminal C esta pegado ZO-1 (L-cingulin y R-actin)
2. En el terminal C esta pegado ZO-2 (actin) y en el N esta MUPP1, parece estar pegado también con ZO-2.
3.En el terminal C esta ZO-3 (actin) pegado con MAGIs
CLAUDIN MONOMER
Is compose of TM1, TM2, TM3, TM4 bonded by EL1 AND EL2.
In the Paracellular space:
EL1is the bond (paracellular ion selectivity)
TM1 + TM2 are bonded maybe by S-S (Still unknown)
Is HCV entry (Claudin-1,-6,-9)
Citosol:
Terminal of TM1 finish w. NH2.
Terminal of TM2 continues to TM3 and connects to it. (Palmitoylation)
In the Paracellular space:
TM3 + TM4 are bonded by EL2 which is doing Oligomerization (CPE binding (Claudin -3,-4).
Citosol:
TM3 docent have a terminal
In TM4 terminal is occurring phosphorylation and finishes with COOH (PDZ- interacting domain)
Endothelial junctions
___________ are present at the apical end of the _______-endothelial space being intimately connected to.
Are dependent on the ___________ based adherens junctions which are located near the _______side of the _______endothelial space.
Endothelial junctions
Tight junctions are present at the apical end of the interendothelial space being intimately connected to
Are dependent on the cadherin based adherens junctions which are located near the basolateral side of the interendothelial space.
Ultrastructural studies of the tight junctions of brain endothelial cells demonstrate close approximation of the _____________ leaflets of adjacent plasma membranes forming a __________________ structure, which prevents the passage of tracers such as ________________ peroxidase (HRP) into the brain.
Ultrastructural studies of the tight junctions of brain endothelial cells demonstrate close approximation of the outer leaflets of adjacent plasma membranes forming a pentalaminar structure, which prevents the passage of tracers such as horseradish peroxidase (HRP) into the brain.
These tight junctions extend circumferentially around the endothelial cells forming a barrier to __________________passage of small _________________ molecules such as
1.
2.
3.
4.
A property referred to as its “______ OR _________” function.
These tight junctions extend circumferentially around the endothelial cells forming a barrier to paracellular passage of small hydrophilic molecules such:
1. as sodium,
2.hydrogen,
3.bicarbonate, .
3. and other ions
A property referred to as its “gate or barrier” function.
Tight junctions also _______________ the movement of membrane molecules between the functionally distinct apical and basolateral membrane surfaces, a property referred to as its “__________” function.
Tight junctions also restrict the movement of membrane molecules between the functionally distinct apical and basolateral membrane surfaces, a property referred to as its “fence” function.
Freeze-fracture studies demonstrate that the tight junctions of cerebral endothelium consist of __-____parallel strands having no discontinuities, which run along the longitudinal axis of the vessel, with numerous lateral anastomotic strands.
Freeze-fracture studies demonstrate that the tight junctions of cerebral endothelium consist of 8–12 parallel strands having no discontinuities, which run along the longitudinal axis of the vessel, with numerous lateral anastomotic strands
Claudin family
The claudin family consists of _______members in mice and humans and exhibit distinct expression patterns in tissue and cells.
Claudins are 18–27-kDa __________ proteins with a short cytoplasmic N-terminus, two extracellular loops, and a COOH terminal cytoplasmic domain which ends in valine.
Claudins are considered to be the main structural components of ____________________ strands and recruit occludin to tight junctions.
Claudin-______ regulates size-selective diffusion of small molecules since claudin-_________ knockout mice show _______________ paracellular permeability to molecules <800D.
The claudin family consists of 24 members in mice and humans and exhibit distinct expression patterns in tissue and cells.
Claudins are 18–27-kDa tetraspan proteins with a short cytoplasmic N-terminus, two extracellular loops, and a COOH terminal cytoplasmic domain which ends in valine.
Claudins are considered to be the main structural components of intramembrane strands and recruit occludin to tight junctions.
Claudin-5 regulates size-selective diffusion of small molecules since claudin-5 knockout mice show increased paracellular permeability to molecules <800D.