TRPV1, ASICs and P2X2/3 expressed in bone cells simultaneously regulate bone metabolic markers in ovariectomized mice

Area of Science:

• Bone Biology
• Neuroscience
• Pain Research

Background:

• Nociceptors, involved in pain sensation, are increasingly recognized for roles beyond pain.
• Transient Receptor Potential Vanilloid 1 (TRPV1) is a nociceptor found in bone, impacting skeletal metabolism.
• Ovariectomy (OVX) in mice leads to altered bone metabolism and pain-like behaviors.

Purpose of the Study:

• To investigate the expression of nociceptors (TRPV1, ASICs, P2X2/3) in bone cells.
• To determine the effect of nociceptor antagonists on bone metabolism markers in OVX mice.

Main Methods:

• Examined nociceptor expression in femoral bone and bone marrow cells from OVX and sham-operated mice.
• Assessed the impact of nociceptor antagonists on key bone metabolic markers (Runx2, Osterix, osteocalcin, RANKL).

Main Results:

• TRPV1, ASIC 2/3, and P2X2/3 were expressed in bone and bone marrow cells.
• Expression of ASIC1/2 and P2X2 was elevated in OVX mice compared to sham controls.
• Nociceptor antagonist treatment significantly suppressed the expression of bone metabolic markers in OVX mice.

Conclusions:

• Multiple nociceptors, including TRPV1, ASICs, and P2X2/3, are present in bone cells.
• These nociceptors appear to regulate both skeletal pain and bone turnover, particularly in the context of OVX.