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. Author manuscript; available in PMC: 2022 Sep 1.
Published in final edited form as: Neuron. 2021 Jul 19;109(17):2691–2706.e5. doi: 10.1016/j.neuron.2021.06.015

Figure 7. TRPV1 promotes IL-23/IL-17A axis-mediated pain in females.

Figure 7.

(A) Trpv1−/− abolishes IL-23-induced pain (I.PL. or I.T., 100 ng) in females.

(B) Mechanical pain by PTX (4 × 2 mg/kg) is not affected by IL-23R antagonist P2305 (I.PL., 10 μg) in Trpv1−/− mice of both sexes.

(C) IL-23 (I.PL. or I.T., 100 ng) induces comparable mechanical pain in female WT and Trpa1−/− mice.

(D) P2305 (I.PL.,10 μg) reduces PTX (4 × 2 mg/kg)-induced mechanical allodynia in female but not male Trpa1−/− mice.

(E) I. PL. capsaicin induces mechanical pain in females at 50–5000 ng but males at 500 and 5000 ng.

(F) Estrogen deficiency by OVX reduces capsaicin-induced mechanical pain (I.PL., 500 ng) in females.

(G) Androgen deficiency by ORX promotes capsaicin-induced mechanical pain (I.PL., 500 ng) in males.

(H) In situ hybridization (RNAScope) images show co-localization of Il17ra and Trpv1 mRNA in female DRG neurons. Positive neurons are indicated with yellow circles. Blue DAPI staining labels nuclei. Scale bar, 10 μm.

(I-K) Quantification of Il17ra+ (I), Trpv1+ (J) and Il17ra+/Trpv1+ (K) subsets of DRG neurons. n = 4 mice per sex (3 sections per mouse).

(L-M) C-fiber elimination by RTX or Trpv1−/− reduces IL-17A-induced pain (I.PL., 100 ng) in females.

(N-O) Effects of IL-17A (10 and 100 ng/ml, 2 min) and capsaicin (300 nM, 2 min) on Ca2+ responses in dissociated DRG sensory neurons from female AdvillinCre/GCamp6f mice. (N) Combined responses of all neurons. 4.67% neurons (13/278) respond to IL-17A (10 ng/ml) and capsaicin, and 11.24% neurons (70/623) respond to IL-17A (100 ng/ml), and 10.91% neurons (68/623) respond to both IL-17A (100 ng/ml) and capsaicin. (O) % quantification of responding neurons. n = 4 or 6 cultures from 3 mice per group.

(P) Trpv1−/− abolishes IL-17A (1 ng/ml, 2 min) potentiation of action potential firing in small-sized DRG neurons from female mice.

Data are mean ± SEM. **p < 0.01, ***p < 0.001; Two-way RM ANOVA with Bonferroni’s post hoc test (A-H, L-M, P); F (12, 92) = 0.2910 (A); F (15, 80) = 0.5561 (B); F (12, 64) = 6.774 (C); F (15, 75) = 5.028 (D); F (28, 168) = 7.304 (E); F (5, 40) = 13.23 (F); F (5, 40) = 4.660 (G); F (4, 32) = 8.850 (L); and F (4, 40) = 13.90 (M); F (13, 91) = 31.63 (P). Unpaired and two-tailed student t test (I-K, O): t = 0.678 (I); t = 1.160 (J); t = 0.1768 (K); t = 6.119 (O).

I.PL., Intraplantar; I.T., Intrathecal; PTX, Paclitaxel; RTX, Resiniferatoxin; OVX, Ovariectomy; ORX, Orchiectomy; BL, Baseline.