Peripherally targeted analgesia via AAV-mediated sensory neuron–specific inhibition of multiple pronociceptive sodium channels
Seung Min Shin, … , Quinn H. Hogan, Hongwei Yu
Seung Min Shin, … , Quinn H. Hogan, Hongwei Yu
Published May 9, 2024
Citation Information: J Clin Invest. 2024;134(13):e170813. https://doi.org/10.1172/JCI170813.
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Research Article Neuroscience

Peripherally targeted analgesia via AAV-mediated sensory neuron–specific inhibition of multiple pronociceptive sodium channels

Abstract

This study reports that targeting intrinsically disordered regions of the voltage-gated sodium channel 1.7 (NaV1.7) protein facilitates discovery of sodium channel inhibitory peptide aptamers (NaViPA) for adeno-associated virus–mediated (AAV-mediated), sensory neuron–specific analgesia. A multipronged inhibition of INa1.7, INa1.6, INa1.3, and INa1.1 — but not INa1.5 and INa1.8 — was found for a prototype and named NaViPA1, which was derived from the NaV1.7 intracellular loop 1, and is conserved among the TTXs NaV subtypes. NaViPA1 expression in primary sensory neurons (PSNs) of dorsal root ganglia (DRG) produced significant inhibition of TTXs INa but not TTXr INa. DRG injection of AAV6-encoded NaViPA1 significantly attenuated evoked and spontaneous pain behaviors in both male and female rats with neuropathic pain induced by tibial nerve injury (TNI). Whole-cell current clamp of the PSNs showed that NaViPA1 expression normalized PSN excitability in TNI rats, suggesting that NaViPA1 attenuated pain by reversal of injury-induced neuronal hypersensitivity. IHC revealed efficient NaViPA1 expression restricted in PSNs and their central and peripheral terminals, indicating PSN-restricted AAV biodistribution. Inhibition of sodium channels by NaViPA1 was replicated in the human iPSC-derived sensory neurons. These results summate that NaViPA1 is a promising analgesic lead that, combined with AAV-mediated PSN-specific block of multiple TTXs NaVs, has potential as a peripheral nerve–restricted analgesic therapeutic.

Authors

Seung Min Shin, Brandon Itson-Zoske, Fan Fan, Yucheng Xiao, Chensheng Qiu, Theodore R. Cummins, Quinn H. Hogan, Hongwei Yu

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Figure 7

Treatment of established neuropathic pain by DRG AAV6-NaViPA1 in male rats.

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Treatment of established neuropathic pain by DRG AAV6-NaViPA1 in male ra...
(A) Silver stain of purified AAVs (a vertical white line denotes that the lanes were run on the same gel but were noncontiguous) were prepared for the experiment in an animal protocol schematically outlined in panel B. (C–F) The time courses (graphs on the left) of vF (C), Pin (D), Heat (E), and (F)Cold before and after DRG injection of either AAV6-NaViPA1 (n = 7) or AAV6-NP (control, n = 8). The measures on the 14th day after TNI and before AAV treatment (tBL) were converted as the peak pain intensity (100%), and the measures of each sensory modality after treatment were normalized to the measures at the tBL and the percentage of pain relief for each modality at multiple time points was calculated (graphs on the right). *P < 0.05, **P < 0.01 and ***P < 0.001 for comparisons to the tBL within group and #P < 0.05, ##P < 0.01, and ###P < 0.001 between groups. Repeated measures 2-way ANOVA for vF and Heat, and Tukey’s (within group) and Bonferroni’s (between groups) post hoc; and nonparametric Friedman ANOVA for Pin and Cold tests and Dunn’s post hoc. Summed average pain relief in the 6-week treatment course showed 52%, 49%, 69%, and 67% reduction of vF-, Pin-, Cold-, and Heat-stimulated mechanical and thermal pain behaviors, respectively (G). ** P < 0.01 *** P < 0.001, unpaired, 2-tailed student’s t test. (H) Results of CPP scores (seconds, s) of preconditioning chamber and of the GBP-paired chamber between AAV-NaViPA1 (n = 7) and AAV-NP (control, n = 8), ***P < 0.001 (unpaired, 2-tailed Student’s t test).