Biology subjects

Boinon, L.

Publications and source records attributed to Boinon, L..

4 recordsLinked to original sources

bioRxiv2025

Phenylhydrazone-based Endoplasmic Reticulum Proteostasis Regulator Compounds with Enhanced Biological Activity

Pharmacological enhancement of endoplasmic reticulum (ER) proteostasis is an attractive strategy to mitigate pathology linked to etiologically-diverse protein misfolding diseases. However, despite this promise, few compounds have been identified that enhance ER proteostasis through defined mechanisms of action. We previously identified the phenylhydrazone-based compound AA263 as a compound that promotes adaptive ER proteostasis remodeling through mechanisms including preferential activation of the ATF6 signaling arm of the unfolded protein response (UPR). However, the protein target(s) of AA263 and the potential for further development of this class of ER proteostasis regulators had not been previously explored. Here, we employ chemical proteomics to demonstrate that AA263 covalently targets a subset of ER protein disulfide isomerases, revealing a potential molecular mechanism for the activation of ATF6 afforded by this compound. We then use medicinal chemistry to establish next-generation AA263 analogs showing improved potency and efficacy for ATF6 activation, as compared to the parent compound. Finally, we show that treatment with these AA263 analogs enhances secretory pathway proteostasis to correct the pathologic protein misfolding and trafficking of both a destabilized, disease-associated 1-antitrypsin (A1AT) variant and an epilepsy-associated GABAA receptor variant. These results establish AA263 analogs with enhanced potential for correcting imbalanced ER proteostasis associated with etiologically-diverse protein misfolding disorders.

cell biology↗

bioRxiv2022

Identification and targeting of a unique NaV1.7 domain driving chronic pain

Despite identification of several small molecules directly targeting the voltage-gated sodium channel NaV1.7, none has been clinically successful. We reported that preventing addition of a small ubiquitin-like modifier (SUMO) on the NaV1.7-interacting cytosolic collapsin response mediator protein 2 (CRMP2) blocked NaV1.7 functions and was antinociceptive in rodents. Here, we discovered a 15 amino acid CRMP2 regulatory sequence (CRS) unique to NaV1.7 that is essential for this regulatory coupling. CRMP2 preferentially bound to the NaV1.7 CRS over other isoforms. Substitution of the NaV1.7 CRS with the homologous domains from the other eight voltage-gated sodium channel isoforms decreased tetrodotoxin-sensitive NaV1.7 currents in rodent sensory neurons. A cell-penetrant version of NaV1.7-CRS reduced NaV1.7 currents and trafficking, decreased presynaptic NaV1.7 localization, reduced spinal neurotransmitter release, and reversed mechanical allodynia in a rat spared nerve injury model of neuropathic pain. Interfering with NaV1.7-CRMP2 coupling did not produce motor impairment and spared thermal, inflammatory, and post-surgical nociception. As proof-of-concept for NaV1.7-targeted gene therapy, we found that NaV1.7-CRS packaged into an adeno-associated virus recapitulated the effects on NaV1.7 function in both rodent and rhesus macaque sensory neurons and both reversed and prevented the development of mechanical allodynia in a neuropathic pain model in male and female rodents. One Sentence SummaryA novel regulatory domain on the voltage gated sodium channel NaV1.7 that can be targeted to produce analgesia.

neuroscience↗

bioRxiv2020

SARS-CoV-2 Spike protein hijacks VEGF-A/Neuropilin-1 receptor signaling to induce analgesia

Global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues unabated. Binding of SARS-CoV-2s Spike protein to host angiotensin converting enzyme 2 triggers viral entry, but other proteins may participate, including neuropilin-1 receptor (NRP-1). As both Spike protein and vascular endothelial growth factor-A (VEGF-A) - a pro-nociceptive and angiogenic factor, bind NRP-1, we tested if Spike could block VEGF-A/NRP-1 signaling. VEGF-A-triggered sensory neuronal firing was blocked by Spike protein and NRP-1 inhibitor EG00229. Pro-nociceptive behaviors of VEGF-A were similarly blocked via suppression of spontaneous spinal synaptic activity and reduction of electrogenic currents in sensory neurons. Remarkably, preventing VEGF-A/NRP-1 signaling was antiallodynic in a neuropathic pain model. A silencing of pain via subversion of VEGF-A/NRP-1 signaling may underlie increased disease transmission in asymptomatic individuals.

neuroscience↗

bioRxiv2020

Studies on CRMP2 SUMOylation-deficient transgenic mice identify sex-specific NaV1.7 regulation in the pathogenesis of chronic neuropathic pain

The sodium channel NaV1.7 is a master regulator of nociceptive neuronal firing. Mutations in this channel can result in painful conditions as well as produce insensitivity to pain. Despite being recognized as a "poster child" for nociceptive signaling and human pain, targeting NaV1.7 has not yet produced a clinical drug. Recent work has illuminated the NaV1.7 interactome, offering insights into the regulation of these channels and identifying potentially new druggable targets. Amongst the regulators of NaV1.7 is the cytosolic collapsin response mediator protein 2 (CRMP2). CRMP2, modified at Lysine 374 (K374) by addition of a small ubiquitin-like modifier (SUMO), bound NaV1.7 to regulate its membrane localization and function. Corollary to this, preventing CRMP2 SUMOylation was sufficient to reverse mechanical allodynia in rats with neuropathic pain. Notably, loss of CRMP2 SUMOylation did not compromise other innate functions of CRMP2. To further elucidate the in vivo role of CRMP2 SUMOylation in pain, we generated CRMP2 K374A knock-in (CRMP2K374A/K374A) mice in which Lys374 was replaced with Ala. CRMP2K374A/K374A mice had reduced NaV1.7 membrane localization and function in female, but not male, sensory neurons. Behavioral appraisal of CRMP2K374A/K374A mice demonstrated no changes in depressive or repetitive, compulsive-like behaviors, and a decrease in noxious thermal sensitivity. No changes were observed in CRMP2K374A/K374A mice to inflammatory, acute, or visceral pain. In contrast, in a neuropathic model, CRMP2K374A/K374A mice failed to develop persistent mechanical allodynia. Our study suggests that CRMP2 SUMOylation-dependent control of peripheral NaV1.7 is a hallmark of chronic, but not physiological, neuropathic pain.

neuroscience↗