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Updated: Aug 6, 2026

Temporomandibular Joint Pain Measurement by Bite Force and Von Frey Filament Assays in Mice
Published on: September 13, 2024
LPA/LPAR signaling drives temporomandibular disorders-like pain through regulating the expression and sensitization
Qiaojuan Zhang1, Shanchun Su1, Pengfei Liang2
1Department of Neurology, Duke University, Durham, NC 27710, USA.
Abstract:
Temporomandibular disorders (TMD) pain is the most common orofacial pain with limited effective treatments. Here, we observed elevated lysophosphatidic acid (LPA), a bioactive lipid, in blood, trigeminal ganglion (TG), and peri-temporomandibular joint (TMJ) tissues in mouse models of TMD-like pain induced by TMJ inflammation or masseter muscle injury. Notably, LPA levels were also elevated in TMD patients' blood and positively correlated with their pain intensity. LPA receptors (LPAR) 1 and 3 were expressed in mouse and human TG neurons and upregulated in TMD-like pain models. Inhibition or knockout of LPAR1 or LPAR3 attenuated TMD-like pain, while LPA injection into the TMJ or masseter muscle evoked pain. Furthermore, we demonstrated that LPA/LPAR signaling upregulates and sensitizes PIEZO2, a mechanosensitive ion channel, in TG neurons via extracellular signal-regulated kinase (ERK). Specific deletion or inhibition of PIEZO2 and suppression of ERK activation in TG neurons mitigated TMD-like pain. These findings suggest that LPA/LPAR signaling drives TMD-like pain via PIEZO2, offering potential therapeutic targets.
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