Poster 27 - Assessing the Potential of a Novel Voltage-Gated Sodium Channel 1.8 Inhibitor as Non-Opioid Therapy for Nerve Growth Factor Induced Pain

Saturday, October 26, 2024

10:00 AM - 12:00 PM EST

Location: Exhibit Hall E, F & G

Presenting Author(s)

SC

Selina Chen

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine
San Diego, California, United States

Co-Author(s)

XW

Xinyan Wei

Student Mentor
University of California, San Diego, United States

Co-Author(s)

AL

Angela Li (she/her/hers)

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine
San Diego, California, United States

Co-Author(s)

IT

Iris Tong

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine, United States

Co-Author(s)

EA

Emanuel T. Aquino

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine, United States

Co-Author(s)

MY

Max Yang

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine, United States
AP

Aaron Perez (he/him/his)

Volunteer Research Intern
University of California, San Diego: Institute of Engineering in Medicine
Vista, California, United States
Sarah Kocian-Rudenberg

Student Mentor
University of California, San Diego: Institute of Engineering in Medicine, California, United States
CW

Chengbiao Wu

Professor
UCSD School of Medicine Dept of Neuroscience, Outreach Program for Advancing Learning in STEM (OPALS), United States

Primary Investigator(s)

Linda Shi, PhD (she/her/hers)

OPALS Program Director, Project Scientist, Co-director IEM
University of California, San Diego: Institute of Engineering in Medicine
La Jolla, California, United States

Last Author(s)

VG

Veronica Gomez-Godinez

Scientist
University of California, San Diego
La Jolla, California, United States

Introduction: New targets for analgesics are urgently needed; opioids, while effective in pain management, carry significant risks of addiction and overdose. NaV1.8, a voltage-gated sodium channel primarily expressed in nociceptor neurons within the peripheral nervous system, has emerged as a promising target for non-opioid pain modulation. This experiment aims to evaluate the efficacy of a novel NaV1.8 inhibitor in modulating channel functionality. The study utilized PC-12, a pheochromocytoma cell line exhibiting properties similar to neurons. Nerve Growth Factor (NGF), involved in pain sensitization, will induce a calcium influx in PC-12 cells, mimicking a nociceptive-like response. This study hypothesizes that an efficacious NaV1.8 inhibitor will suppress NGF-induced responses in PC-12 cells.

Materials and

Methods: The experimental design includes four separate samples of PC-12 cells. Dish 1 compared cell behavior before and after the addition of DMSO. Dish 2, 3, and 4 pre-stimuli included cells and DMSO, and post-stimuli included NGF in all dishes. Dish 2 is used as the control, with no drug dosage; Dish 3 included 100 nM of the inhibitor post-stimuli; and Dish 4 included 10 nM. Prior to imaging, cells were loaded with Fluo-4 AM, a fluorescent calcium indicator, to visualize calcium signaling. Images were then captured for 15 minutes, before and after the stimuli, using a Zeiss 40x objective microscope at 3-second intervals per sample. The average brightness of the cells, reflecting calcium intensity, was measured using ImageJ at pre-stimulation, immediately post-stimulation, and 5, 10, and 15 minutes post-stimulation. The values were then normalized and compiled into graphs.

Results, Conclusions, and Discussions: The results have supported the hypothesis. In the Dish 1 control experiment, calcium intensity increased after the addition of vehicle DMSO, ruling out the possibility of DMSO decreasing calcium intensity. In Dish 2, the addition of NGF in vehicle DMSO was shown to increase cell calcium intensity. In both Dish 3 (NGF + 100 nM NaV1.8 inhibitor) and dish 4 (NGF + 10 nM NaV1.8 inhibitor), calcium intensity declined. The decline in Dish 4 was not as significant as that in Dish 3. While analyzing images for each dish, we encountered unavoidable experimental difficulties that caused slight decreases in calcium intensity: 1) photobleaching; 2) the natural propensity of PC12 cells to eject Fluo-4 AM from their cell bodies. The results showed that the addition of this novel NaV1.8 inhibitor reduced the calcium intensity raised by NGF in PC-12 cells. This suggests that this new NaV1.8 inhibitor may be used to inhibit NGF-induced pain signaling, providing evidence for its potential therapeutic use in the management of neuropathic pain, which is usually related to elevated NGF levels. However, this claim is not conclusive since in the control sample (Dish 1), calcium signals were increased during the 15 min experimental period. In addition, PC12 cells can not exactly mimic the behavior of nociceptors i.e. dorsal root ganglion cells (DRG), peripheral neurons that play a major role in pain signaling, have not been obtained. Therefore, this result remains to be further validated using dorsal root ganglion (DRG) cells, peripheral neurons that play a major role in pain signaling. Future studies should also further investigate the use of this NaV1.8 inhibitor in animal pain models to demonstrate its efficacy in vivo and potentially assess its safety and toxicity.

Acknowledgements (Optional): This work was supported by a generous gift from Beckman Laser Institute Inc. to LS and VGG. The high school students (*) participated in the UCSD IEM OPALS internship. Special thanks to Dr. Shu Chien from UCSD Bioengineering and Dr. Lizhu Chen from CorDx Inc. for their donations.

References (Optional):