Background: The synthetic chemical 1,4-dioxane is used as industrial solvent, food and care product additive. 1,4-Dioxane has been noted to influence the nervous system in long-term animal experiments and in humans, but the molecular mechanisms underlying its effects on animals were not previously known.

Results: Here, we report that 1,4-dioxane potentiates the capsaicin-sensitive transient receptor potential (TRP) channel TRPV1, thereby causing hyperalgesia in mouse model. This effect was abolished by CRISPR/Cas9-mediated genetic deletion of TRPV1 in sensory neurons, but enhanced under inflammatory conditions. 1,4-Dioxane lowered the temperature threshold for TRPV1 thermal activation and potentiated the channel sensitivity to agonistic stimuli. 1,3-dioxane and tetrahydrofuran which are structurally related to 1,4-dioxane also potentiated TRPV1 activation. The residue M572 in the S4-S5 linker region of TRPV1 was found to be crucial for direct activation of the channel by 1,4-dioxane and its analogues. A single residue mutation M572V abrogated the 1,4-dioxane-evoked currents while largely preserving the capsaicin responses. Our results further demonstrate that this residue exerts a gating effect through hydrophobic interactions and support the existence of discrete domains for multimodal gating of TRPV1 channel.

Conclusions: Our results suggest TRPV1 is a co-receptor for 1,4-dioxane, and that this accounts for its ability to dysregulate body nociceptive sensation.

Electrophysiological data were mainly collected from traditional patch-clamp recordings and Ca²⁺ imaging. All behavioral experiments with mice were conducted in a double-blind manner. Paw-withdrawal latency of thermal or mechanical hyperalgesia was determined by a temperature-controlled Plantar Test Instrument and von Frey apparatus, respectively.

This dataset contains nine excel sheets including all data used to analyze the effect of the industrial solvent 1,4-Dioxane on thermal TRPV1 channel. Each excel sheet corresponds to a figure, and all statistical results along with the statistical methods are exhibited in the excel sheet.

1) Fig1-1,4-Dioxane ms figsupplement data

Data used for Figure 1 ‘1,4-Dioxane causes mice hyperalgesia via TRPV1 activation’. (1) Experimental data from mice obtained using the Radiant Heat and Von Frey assay and was illustrated in Fig 1a&b. (2) Data collected for paw volume examination and was shown in Fig 1c. (3) Ca²⁺ imaging data and electrophysiological data obtained in acutely dissociated DRG and TG neurons from Trpv1^+/+ and Trpv1^-/- mice and were demonstrated in Fig 1d-m.

2) Fig2-1,4-Dioxane ms figsupplement data

Electrophysiological data were collected from TRPV1-expressing HEK293 cells by single-channel recordings or whole-cell recordings and were used to illustrate the gating and modulation of TRPV1 channels by 1,4-dioxane as shown in Figure 2.

3) Fig3-1,4-Dioxane ms figsupplement data

This data set was obtained from TRPV1-expressing HEK293 cells stimulated by heat and was used to analyze the current amplitudes and normalized responses as illustrated in Figure 3.

4) Fig4-1,4-Dioxane ms figsupplement data

Data were collected to analyze the activation of TRPV1 under inflammation-related conditions in Figure 4. Electrophysiological data were obtained and analyzed for Figure 4a-f. Behavior data shown in Figure 4g were collected from mice under carrageenan-induced inflammation conditions using the Radiant Heat and Von Frey assay.

5) Fig5-1,4-Dioxane ms figsupplement data

Electrophysiological data obtained by whole-cell recordings in HEK293 cells were used for Figure 5 to demonstrate the residue M572 within the S4-S5 linker region of TRPV1 mediates the effect of 1,4-dioxane and its analogues.

6) Fig6-1,4-Dioxane ms figsupplement data

Electrophysiological data were collected for Figure 6. Whole-cell recordings were performed in HEK 293 cells transiently transfected with individual mutation.

7) FigS1-1,4-Dioxane ms figsupplement data

Electrophysiological data were collected for Figure S1 to show effects of 1,4-dioxane on variable TRP channels.

8) FigS3-1,4-Dioxane ms figsupplement data

Electrophysiological data were obtained for Figure S3 to illustrate the amplitude of TRPV1 single-channel currents elicited by different conditions.

9) FigS4-1,4-Dioxane ms figsupplement data

Electrophysiological data were collected for Figure S4 to exhibit the inhibitory effect of ruthenium red (RR) on TRPV1 currents.