Implants · single question
Each of the following molecules plays a significant role in OSTEOINDUCTION EXCEPT one. Which is the EXCEPTION?
Show answer and explanation
Correct answer: C. Interleukin-8 (IL-8)
Osteoinduction involves molecules that stimulate undifferentiated cells to become bone-forming cells. BMP is THE classic osteoinductive molecule — it directly stimulates mesenchymal cells to differentiate into osteoblasts. TGF-β promotes bone matrix formation. FGF stimulates osteoblast proliferation. IL-8 is a pro-inflammatory CHEMOKINE that recruits neutrophils and macrophages to sites of infection/injury — it is NOT osteoinductive. It is involved in inflammation, not bone formation.
- A. INCORRECT — TGF-β promotes osteoblast proliferation and matrix production, and is a significant mediator of osteoinduction and bone repair.
- B. INCORRECT — BMPs (bone morphogenetic proteins) are the MOST potent known osteoinductive factors, capable of inducing bone formation de novo. BMP-2 and BMP-7 are FDA-approved for clinical use.
- C. CORRECT (EXCEPTION) — Interleukin-8 (IL-8) is primarily a pro-inflammatory chemokine that attracts neutrophils; it plays a role in inflammation but is NOT a primary mediator of osteoinduction.
- D. INCORRECT — FGF promotes osteoblast proliferation and angiogenesis, playing a role in bone formation and osteoinduction.