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Updated: May 28, 2026

Development of Recombinant Proteins to Treat Chronic Pain
Published on: April 11, 2018
Soluble epoxide hydrolase limits mechanical hyperalgesia during inflammation.
Christian Brenneis1, Marco Sisignano, Ovidiu Coste
1Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe-University, Frankfurt, Germany. Christian.Brenneis@childrens.harvard.edu
Soluble epoxide hydrolase (sEH) inactivates 8,9-epoxyeicosatrienoic acid (EET), a molecule that sensitizes pain-sensing neurons. Inhibiting sEH may worsen pain during inflammation, suggesting caution when targeting this pathway for cardiovascular diseases.
Area of Science:
- Biochemistry
- Neuroscience
- Pharmacology
Background:
- Cytochrome-P450 (CYP450) epoxygenases metabolize arachidonic acid into epoxyeicosatrienoic acids (EETs).
- Soluble epoxide hydrolase (sEH) rapidly hydrolyzes three major EET regioisomers (8,9-, 11,12-, and 14,15-EET).
- The role of sEH in nociceptive processing during peripheral inflammation was investigated.
Purpose of the Study:
- To investigate the role of sEH in nociceptive processing during peripheral inflammation.
- To determine how sEH activity affects EET levels and nociceptor sensitization.
- To explore the potential link between sEH, EETs, and pain during inflammation.
Main Methods:
- Examined sEH expression in dorsal root ganglia (DRG) neurons.
- Measured EET and dihydroxyeicosatrienoic acid (DHET) levels in sEH-deficient (sEH(-/-)) mice.
- Utilized cellular imaging to assess calcium flux responses to 8,9-EET.
- Investigated the effects of 8,9-EET on TRPA1-expressing neurons and nociceptive responses in vivo.
Main Results:
- sEH is expressed in medium and large DRG neurons; sEH(-/-) mice exhibit higher EET levels.
- 8,9-EET directly elicits calcium flux in nociceptors and sensitizes TRPA1-expressing neurons.
- sEH(-/-) mice display heightened mechanical hyperalgesia during inflammation.
- 8,9-EET injection reduces mechanical pain thresholds in naive mice.
Conclusions:
- sEH inactivates 8,9-EET, thereby regulating mechanical hyperalgesia during inflammation.
- 8,9-EET sensitizes TRPA1-expressing nociceptors, contributing to pain signaling.
- Targeting CYP450 pathways, considered for cardiovascular diseases, may lead to pain-related side effects.
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