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Principal Investigator: Sidharth Tyagi
Organization: YALE UNIVERSITY
Fiscal Year: 2024
Award: $31,570
Funding agency: National Institute of Neurological Disorders and Stroke
Project Summary: Targeted degradation of NaV1.8 as a therapeutic strategy for pain.
Chronic pain is a massive global health burden, and therapeutic options for pain are limited and have a spectrum
of adverse effects. Alternative treatments for pain that are specific, effective, and non-addictive are an urgent
need. NaV1.8 channels are critical determinants of nociceptor excitability—they contribute to most of the current
underlying the rising phase of action potentials and have been implicated in human pain conditions and in animal
models of pain. Gain-of-function mutations in NaV1.8 result in painful neuropathies in humans, and a loss-of-
function in NaV1.8 dulls pain sensitivity in animal models. This genetic dichotomy suggests that reducing sodium
influx through NaV1.8 channels can provide analgesia without CNS side-effects or addictive potential. To date,
the principal strategy for targeting these channels has been to directly inhibit sodium conductance through the
channel. While promising, agents with this mechanism of action have not yet been deployed in the clinic. An
innovative approach may be to reduce the number of channels present at the neuronal surface by selective
degradation.
I have generated a bifunctional protein (named UbiquiNaV) composed of a NaV1.8 selective binding sequence
and the catalytic domain of the NEDD4 ubiquitin ligase. This engineered protein should bind specifically to NaV1.8
and subsequently ubiquitinate the channel, targeting it for degradation. My preliminary data shows that
expression of UbiquiNaV in rat DRG neurons reduces NaV1.8 current. This proposal will test the hypothesis that
this bifunctional molecule will reduce nociceptor excitability via selective degradation of NaV1.8 channels. In Aim
1, I will investigate the specificity of UbiquiNaV for NaV1.8 and demonstrate how UbiquiNaV expression impacts
rat nociceptor excitability. Aim 2 will use a live-cell imaging assay developed in our lab coupled with an inducible
activation mechanism to examine the temporal and spatial regulation of NaV1.8 channels in DRG neurons by
UbiquiNaV. Together, my work will a) delineate the mechanism of action of this newly engineered bifunctional
molecule, and b) reveal the selectivity of UbiquiNaV for NaV1.8. In doing so, this work will demonstrate the viability
of targeted degradation of NaV1.8 as an analgesic strategy.
Terms: <Absence of pain sensation><Absence of sensibility to pain><Actin-Activated ATPase><Action Potentials><Adverse effects><Afferent Neurons><Analgesic Agents><Analgesic Drugs><Analgesic Preparation><Analgesics><Animal Model><Animal Models and Related Studies><Anodynes><Antinociceptive Agents><Antinociceptive Drugs><Assay><Axon><Binding><Bioassay><Biological Assay><Catalytic Core><Catalytic Domain><Catalytic Region><Catalytic Site><Catalytic Subunit><Cell surface><Clampings><Clathrin><Clinic><Closure by clamp><Common Rat Strains><Coupled><Data><Development><Dimerization><Disease><Disorder><Dorsal Root Ganglia><Electrophysiology><Electrophysiology (science)><Endocytosis><Engineering><Feels no pain><Genetic><Goals><Health Care Costs><Health Costs><Healthcare Costs><Human><Immunoblotting><Ion Channel><Ionic Channels><Isoforms><KO mice><Knock-out Mice><Knockout Mice><Label><Laboratories><Link><Mediating><Membrane Channels><Membrane Protein Gene><Membrane Proteins><Membrane-Associated Proteins><Mentors><Modern Man><Molecular Interaction><Myosin ATPase><Myosin Adenosine Triphosphatase><Myosin Adenosinetriphosphatase><Myosins><Na element><Names><Nerve Cells><Nerve Unit><Neural Cell><Neurocyte><Neurology><Neurons><Neurophysiology / Electrophysiology><Neurosciences><No sensitivity to pain><Nociceptors><Null Mouse><Pain><Pain Control><Pain Therapy><Pain management><Painful><Peripheral><Phase><Physicians><Physiologic><Physiological><Protein Dimerization><Protein Engineering><Protein Isoforms><Proteins><Rapamune><Rapamycin><Rat><Rats Mammals><Rattus><Reagent><Regulation><Research><Scientist><Sensory><Sensory Neurons><Sirolimus><Sodium><Sodium Channel><Sodium Ion Channels><Specificity><Spike Potential><Spinal Ganglia><Stimulus><Surface><Surface Proteins><System><Tail><Testing><Therapeutic><Therapeutic Agents><Time><Ubiquitilation><Ubiquitin Ligase Component Gene><Ubiquitin Ligase Gene><Ubiquitination><Ubiquitinoylation><United States><Validation><Video Microscopy><Videomicrography><Videomicroscopy><Western Blotting><Western Immunoblotting><Work><alternative treatment><analgesia><chronic pain><density><developmental><disability><dorsal root ganglion><electrophysiological><gain of function mutation><genetic protein engineering><global health><ineffective therapies><ineffective treatment><innovate><innovation><innovative><live cell image><live cell imaging><live cellular image><live cellular imaging><loss of function><model of animal><name><named><naming><neural cell body><neuronal><neuronal cell body><neuronal excitability><neuropathic pain><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><nociceptive neurons><novel><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel therapeutics><novel therapy><overexpress><overexpression><pain killer><pain medication><pain model><pain reliever><pain sensation><pain sensitivity><pain treatment><pain-sensing neurons><pain-sensing sensory neurons><pain-sensing somatosensory neurons><painful neuropathy><painful sensation><painkiller><protein blotting><protein design><side effect><small molecule><soma><trafficking><treatment strategy><ubiquination><ubiquitin conjugation><ubiquitin ligase><validations><voltage><voltage clamp>