BSP & osteoponton Flashcards
What are two types of bones?
Hard cortical bone
spongy cancellous bone
Cancellous bone composition
25% organic
- 90% collagen I and V
- 10% other stuff
70% hydroxyapatite
5% water
what is ceramic?
an inorganic compound that is heated and cooled quickly
what is bioceramic? example?
a biocompatible ceramic
calcium hydroxyapatite
Do osteoblasts and osteoclasts come from the same progenitor stem cells?
no.
osteoblasts < mesenchymal SC
osteoclasts < hematopoietic SC
What do Osteoblasts become after mineralization?
osteocytes
(commitment) Mesenchymal progenitor > osteo-progenitor. Which signals?
BMP, runx, wnt
(proliferation) Osteo-progenitor > Immature osteoblast. Which signals?
runx, osterix
(mature matrix) immature osteoblats > osteoblats. Which signals?
BSP, alkaline phosphatase, collagen I
What is the matrix produced around osteoblasts called and what happens to it
osteoid and it gets mineralized
What fits in the gaps of the spongy bones?
bone marrow
What is the formula for hydroxyapatite
Ca10 (PO4)6 (OH)2
What are two of the important non-collagenous proteins that bind to hydroxyapatite?
BSP (bone sialoprotein)
OPN (Osteopontin)
What are some characterists similar and different between BSP and OPN?
similarities
- binds to hydroxyapatite
- binds to RGD integrins
- highly phosphorylated
Differences
- BSP: 2-3 glutamic motif
- BSP is more tissue specific
- BSP is highly sulfated too
- BSP has high sialic acid content
- OPN: polyaspartic motif
- OPN is broad tissue specific
What are some characterists similar and different between BSP and OPN?
similarities
- binds to hydroxyapatite
- binds to RGD integrins
- highly phosphorylated
Differences
- BSP: 2-3 glutamic motif
- BSP is more tissue specific
- BSP is highly sulfated too
- BSP has high sialic acid content
- OPN: polyaspartic motif
- OPN is broad tissue specific
What are some characterists similar and different between BSP and OPN?
similarities
- binds to hydroxyapatite
- binds to RGD integrins
- highly phosphorylated
Differences
- BSP: 2-3 glutamic motif
- BSP is more tissue specific
- BSP is highly sulfated too
- BSP has high sialic acid content
- OPN: polyaspartic motif
- OPN is broad tissue specific
Which proteins are expressed during the differentiation phase?
Alkaline Phosphatase
BSP (also early mineralization)
Which proteins are expressed during the Mineralization phase?
OPN
SPARC (always)
Draw a western blot for termporal expression of all protein
haha
Where are early crystals formed?
What are these crystals made of?
What promotes this growth?
in the collagen hole zones
hydroxyapatite crystals
BSP
vesicles (w/ alkaline phosphatase and nucleotide
pyrophosphatase/phosphodiesterase, Annexin)
What are the main places the vesicles start minerlizing?
osteoid
cartiliage
dentin
What brings in calcium in the vesicles?
annexin
What brings in phosphate in the vesicles?
Type III Na dependent transporters
What do MMPs do inside vesicles?
growth factor activation
