Pruritus Model Introduction

Pruritus, commonly known as itching, is a prevalent symptom that can significantly impact the quality of life in both humans and animals, including mice. It serves as a crucial behavioral response to various skin conditions, allergens, or systemic diseases. Understanding pruritus in mice is essential for developing effective treatments and studying the underlying mechanisms of itch.

In mice, pruritus can be induced experimentally through several methods, such as the application of pruritogens (substances that trigger itching) or by using genetically modified strains that have altered sensitivity to itchy stimuli. The study of pruritus in mice is particularly valuable due to the similarities in the basic biological mechanisms underlying itch in humans and mice.

The translational aspect of pruritus research in mice is significant for human medicine, as findings from these studies can lead to the identification of novel therapeutic targets and strategies for treating chronic pruritus, which affects millions of people worldwide due to conditions like eczema, psoriasis, and allergies.

Results

MC903-induced Pruritus Model

Establishment of Pruritus Mouse Model

• Experimental Animals: C57BL/6, B-hIL31/hIL31RA/hOSMR mice, female, 8-10 weeks old
• Modeling reagent: MC903 (Calcipotriol)
• Modeling method: Mice received MC903 (2 nmol/20 μL) on right ear every two days for 9 times. Camera was used to record behavior for 2 times, 1 hours every time. The video is recorded to assess their itching behavior.

Readouts
Included tests	Body Weight
	Scraching bouts for 60 min post hIL31 injection
Optional tests	Clinical scores	Ear thickness
	Skin histopathology (H&E)	Immune cell infiltration
		Epidermal thickness
		Histology score
	Molecular levels	Serum total IgE
	Behavior	Pruritus

Efficacy of Pruritus Evaluation of Nemolizumab (Anti-IL31Rα) in MC903-induced AD Model of B-hIL31/hIL31R/hOSMR Mice

Figure1. Scratching bouts in 60 min on Day 14 (A), Day 17 (B)

hIL-31-induced Pruritus Model

• Animals: B-hIL31/hIL31RA/hOSMR mice, female, 8-10 weeks old
• Reagents: human IL31 protein
• Methods: Mice is injected with hIL-31 protein in the cheek, and then a video is recorded to assess their itching behavior.

Readouts
Included tests	Body weight
	Scraching bouts for 60 min post hIL31 injection

Criteria for scratch bouts:
Mice raise a hind leg towards the cheek, back and ear, and scratch several times over one or a few seconds, then put that leg down.
This series of actions is counted as one scratch bout.

Efficacy study of anti-hIL31R (Nemolizumab) assessment in pruritus model

Figure2. Scratching bouts in 60min on Day 1 (A), Day 4 (B), Day 10 (C),The increase in itching bouts of mice on days 1, 4, and 10 (D)