Fig 1: Potent and selective antagonists of Nav1.7 and Nav1.8 inhibit thermally evoked responses in sensitized adult DRG cultures. (A) Raster plots of three representative electrodes at 37 °C (left), 45 °C (middle), and after the addition of 30 nM HWTX-IV. (B) Raster plots of three representative electrodes at 37 °C, 45 °C, and after the addition of 300 nM A-803467. Summarized percentage of temperature responsive electrodes at baseline and after the addition of (C) Nav1.7 blocker (30 nM HWTX-IV) and (D) Nav1.8 blocker (300 nM A-803467).
Fig 2: Potent and selective antagonists of Nav1.7 and Nav1.8 inhibit spontaneous activity in sensitized DRG cultures (A) Representative raster plots of three active electrodes in baseline (left) and after addition (right) of either 23 nM ICA-121431 (top), 30 nM huwentoxin-IV (HWTX-IV) (middle), or 300 nM A-803467 (bottom). Inhibitors of sodium channel subtypes were administered on cultures sensitized with IL6 + NGF for a period of 72 hours. (B) Representative raster plots of three active electrodes in baseline and equivalent treatments in DIV21 embryonic cortical cultures. (C) Mean normalized change in firing rate from baseline of DRG cultures after addition of ICA-121431 (Nav1.1/1.3), HWTX-IV (Nav1.7), or A-803467 (Nav1.8). Error bars are represented as mean ± standard error of the mean (SEM). * p < 0.05, ** p < 0.01, and *** p < 0.001.
Fig 3: Voltage-gated sodium currents in NGN2iSN. Sodium currents (INa) from NGN2iSN are predominantly mediated by TTX-S Nav channels. (A,B) Representative INa current traces in control (A) and the presence of 300 nM TTX (B) elicited by the voltage protocol shown in the inset. (C) NGN2iSN sodium current (INa) density upon depolarization to −10 mV (highlighted in red in A and B) calculated from peak total and TTX-R INa current in nA/pF. (D) Voltage- dependence of activation (filled symbols) and steady-state inactivation (SSI; empty symbols) of the total (●, ○) and TTX-R (300 nM TTX, ▪, □) components of INa. (E) Relative mRNA expression of SCN9A and SCN10A transcripts in NGN2iSN (normalized to the house-keeping genes B2M, PPIA, and GAPDH), error bars presented as SEM, n = 3–4 biological replicates. (F) Immunoreactivity against human Nav1.7 and Nav1.8 antibodies.
Fig 4: Expression of ion channels and membrane proteins in H9NGN2‐induced sensory neurons (iSNs) that modulate neuronal excitability. (A–E) Immunocytochemistry staining in H9NGN2 iSNs: (A) GABAB receptor subunits GABBR2 (green) and GABBR1 (red). (B) G protein–coupled inwardly rectifying potassium channel subunit 1 (GIRK1/KCNJ3, green) and GABBR1 (red). (C) Voltage‐gated calcium channel (CaV2.2/CACNA1B, green) and GABBR1 (red). (D) Voltage‐gated sodium channel (NaV1.7/SCN9A, green) and neuronal marker TUJ1 (red). (E) Voltage‐gated sodium channel (NaV1.8/SCN10A, green) and neuronal marker TUJ1 (red). (F–I) Scaled transcriptomic expression (TPM) of curated genes in discrete classes of ion channels and membrane receptors. Expression levels in iSNs (dark blue, TPM values denoted) are compared to primary human sensory neurons (light blue), with genes pertinent to this study highlighted in red. (F) G protein–coupled inwardly rectifying K+ channel (GIRK) subunit expression. (G) GABAB receptor subunit expression. (H) Calcium channel subunit expression. (I) Hyperpolarisation‐activated, cyclic nucleotide‐gated (HCN) channel subunit expression.
Fig 5: Expressions of Nav1.7 in the TG. (A–C) Immunostaining showing Nav1.7 expression in the TG. The protein expression of Nav1.7 increased in the TG in AITC-treated group. (D–F) Figures present enlarged yellow squares in a, b, and c, respectively. (G,H) The expression ratios were presented and the size-dependent Nav1.7 expression neurons were counted. The highest level of nav1.7 expression was observed in AITC-treated groups. (I) Expressions of Nav1.7 were analyzed using western blot (Scale bar = 20 µm, Error bars represent SEM; **p < 0.01, n = 4 each).
Supplier Page from Abcam for Anti-Nav1.7 antibody