THE OFFICIAL NEWS SOURCE OF ACR CONVERGENCE 2022 • NOVEMBER 10-14



Alia Obeidat, PhD: Mrgprd-expressing nonpeptidergic C-fibers in the mouse knee

Alia Obeidat, PhD
Alia Obeidat, PhD

Poster presenter: Alia Obeidat, PhD, Division of Rheumatology, Rush University Medical Center

Poster title: Anatomical Distribution of Mrgprd-expressing Nonpeptidergic C-fibers in the Mouse Knee

Scheduled poster session day and time: Saturday, Nov. 7, 9 – 11 a.m.

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What is your poster about?

The poster describes the anatomical distribution of The Mas-related G protein-coupled receptor D (Mrgprd)-expressing nonpeptidergic C-fibers (as subset of NaV1.8 + nociceptors) in healthy and osteoarthritis mouse knee. We previously observed neuroplasticity in NaV1.8 + nociceptors (NaV1.8 marks the majority of nociceptors, including more than 90% of C-fibers) in knee joints from our osteoarthritis model (destabilization of medial meniscus—DMM model), and in this study we focused on which subsets of nociceptors are responsible for the intraarticular neuroplasticity seen after OA. 

Why did you decide to investigate this topic?

Mrgprd, which mediate behavioral sensitivity to noxious mechanical stimuli, marks about 75% of all IB4+ nonpeptidergic nociceptive neurons. The Mrgprd-expressing neuron has a potential role in mechanosensation, making them an interesting subject in the context of OA pain, which is why we used Mrgprd-EGFP reporter mice and investigated if they are present in the murine OA joint. 

What excites you most about your work?

There is a paucity of literature about the role of intraarticular sensory neuronal remodeling in OA initiation or progression, but I think this is a very interesting topic to investigate. There is strong clinical evidence suggesting that OA pain is driven by peripheral input.

What are you working on next related to this poster? 

We are trying to explore specific subsets of neurons that undergo plasticity after OA and what is their role in OA pain or joint damage and how can we intervene to alleviate pain and protect joint.