Targeting intrinsically disordered regions facilitates discovery of calcium channels 3.2 inhibitory peptides for adeno-associated virus–mediated peripheral analgesia. Issue 12 (14th December 2022)

• Record Type: Journal Article
• Authors: Shin, Seung Min; Lauzadis, Justas; Itson-Zoske, Brandon; Cai, Yongsong; Fan, Fan; Natarajan, Gayathri K.; Kwok, Wai-Meng; Puopolo, Michelino; Hogan, Quinn H.; Yu, Hongwei
• Is Part Of: Pain. Volume 163:Issue 12(2022)
• Page Start: 2466
• Page End: 2484
• Publication Date: 2022-12-14
• Subjects: T-type/Cav3.2 channels -- Peripheral nervous system -- Dorsal root ganglia -- Adeno-associated virus -- Peptide aptamer -- Neuropathic pain; Pain -- Periodicals; Douleur -- Périodiques; Anesthésie -- Périodiques; Pain; Electronic journals; Periodicals; Electronic journals; 616.0472
• DOI: 10.1097/j.pain.0000000000002650
• Languages: English
• ISSNs: 0304-3959

Abstract

Abstract : Supplemental Digital Content is Available in the Text. Targeting intrinsically disordered regions facilitates discovery of T-type/calcium channels 3.2 (CaV 3.2) inhibitory peptides. Adeno-associated virus–mediated expression of prototypic CaV 3.2iPA1 and 2 in dorsal root ganglia primary sensory neurons in vivo produces sustained inhibition of calcium channel current conducted by CaV 3.2/T-type channels and attenuates stimulated and spontaneous pain in rats with neuropathic pain. Abstract: Ample data support a prominent role of peripheral T-type calcium channels 3.2 (CaV 3.2) in generating pain states. Development of primary sensory neuron-specific inhibitors of CaV 3.2 channels is an opportunity for achieving effective analgesic therapeutics, but success has been elusive. Small peptides, especially those derived from natural proteins as inhibitory peptide aptamers (iPAs), can produce highly effective and selective blockade of specific nociceptive molecular pathways to reduce pain with minimal off-target effects. In this study, we report the engineering of the potent and selective iPAs of CaV 3.2 from the intrinsically disordered regions (IDRs) of CaV 3.2 intracellular segments. Using established prediction algorithms, we localized the IDRs in CaV 3.2 protein and identified several CaV 3.2iPA candidates that significantly reduced CaV 3.2 current in HEK293 cells stably expressing human wide-type CaV 3.2. Two prototype CaV 3.2iPAs (iPA1 and iPA2) derived from the IDRs of CaV 3.2 intracellular loops 2 and 3, respectively, were expressed selectively in the primary sensory neurons of dorsal root ganglia in vivo using recombinant adeno-associated virus (AAV), which produced sustained inhibition of calcium current conducted by CaV 3.2/T-type channels and significantly attenuated both evoked and spontaneous pain behavior in rats with neuropathic pain after tibial nerve injury. Recordings from dissociated sensory neurons showed that AAV-mediated CaV 3.2iPA expression suppressed neuronal excitability, suggesting that CaV 3.2iPA treatment attenuated pain by reversal of injury-induced neuronal hypersensitivity. Collectively, our results indicate that CaV 3.2iPAs are promising analgesic leads that, combined with AAV-mediated delivery in anatomically targeted sensory ganglia, have the potential to be a selective peripheral CaV 3.2-targeting strategy for clinical treatment of pain.