Path Mechanisms I 3: Immune Response and Bone Resorption

Question 1

What are the two precursors to an osteoclast?

Answer 1

Osteoblast/Stromal Cell

Osteroclast precursor

Question 2

What is the name of the Membrane Ligand on the Osteoblast/Stromal Cell that allows for the process of bone resorption to start?

Answer 2

RANKL (Ligand)

Question 3

What is the receptor that RANKL binds with and what is the secondary receptor that the Osteoblast interacts with?

Answer 3

RANK receptor on Osteoclast precursor cell

OPG Receptor

Question 4

What ratio determines whether bone resorption or bone formation occurs?

Answer 4

RANKL/OPG Ratio

Question 5

What is the ratio that signals for Resorption?

Answer 5

There needs to be more RANKL so either:

RANKL increases while OPG stays the same OR

OPG decreases while RANKL stays the same

Question 6

What regulates differentiation of osteoclasts?

Answer 6

Inflammatory cytokines

Lipid mediators

Question 7

Which two Interleukins are involved in osteoclast differentiation?

Answer 7

IL-1

IL-6

Question 8

What other Cytokines and Lipid Mediators are involved in osteoclast differentiation?

Answer 8

TNF-alpha
Prostaglandin E2 (PGE2)
RANKL

Question 9

In the model of differentiation of osteoclasts due to inflammatory cytokines what do the presence of inflammatory cytokines induce?

Answer 9

Stromal Cells/Osteoblasts to upregulate RANK-L

Question 10

What does the upregulation of RANK-L cause?

Answer 10

Osteoclast differentiation and bone resorption

Question 11

Where do the cytokines and mediators come from in the Periodontium?

Answer 11

Macrophages