BC: Lecture 2 Flashcards
What lineage are osteoclasts derived from?
Hematopoietic lineage
Are mature osteoclasts multinucleated?
Yes
What does expression of proton pumps to reduce pH around bone cause the formation of?
Ruffled border
Are osteoclasts responsible for anything that has to do with bone resorption, including
tooth roots and alveolar bone?
Yes
Where does bone growth occur?
Epiphyseal plate
Why must modeling occur?
Because it is needed to maintain bone shape
What is the master transcription factor for osteoclasts?
NFATc1
What proteins regulate osteoclast activity
RANKL
M-CSF
What does RANKL do?
promotes fusion of osteoclasts and their differentiation
What does M-CSF do?
Promote osteoclast proliferation and survival
Once the sealing zone has formed, how is the bone actively degraded?
Through the generation of protons in the space
What proteins do this?
a. Carbonic anhydrase II
b. ATPase pumps
What is the pH of the resorption bay generated by the osteoclasts?
~4.5
What channel maintains the charge in the space created by the sealing zone?
Chloride channel
What protein released by osteoclasts degrades matrix vesicles?
Cathepsin K
What does impaired osteoclast function lead to?
Osteoporosis
What are the two major clinical forms of impaired osteoclasts?
Autosomal dominant Autosomal recessive