Rhino Mouse Acne Model Imavita

Rhino Mouse Acne model



Rhino mouse acne model has been useful in assessing the comedolytic activity of drugs/compounds (i.e. retinoids)

Phenotype Hrrh/Hrrh is due to an autosomal recessive mutation in the hairless (hr) gene

In Rhino mice, utriculi are derived from the infundibular zone of the initial follicular units, and are histologically similar to comedones


Protocol summary

Rhino mouse strain animals with application of compounds / new drugs on back skin

Histology evaluation on skin of utriculi (principal efficacy endpoint)

Evaluation of in vivo / ex vivo / analysis as secondary efficacy  endpoints


Typical results

Typical results obtained with this model are presented below:

EvaluationParameterGroup control
(excipient / topical)
Test group
(retinoid / topical)
In vivoBodyweightNE (No Effect)NE or decrease
Back skin scaling
(visual scoring)
NESlight increase (dry skin appearance)
Back skin erythema
(visual scoring)
NEIncrease (irritation)
Back skin thickness
NENE or increase
Epidermis thickness
(OCT / Optical Coherence Tomography)
Ex vivo
HES (Overview)
UtriculiNEVery important decrease
(-80 to -90%)
Sebaceous glandsNENE on short periods of treatment
Epidermis thicknessNEIncrease
(epidermal hyperplasia)
Dermis inflammationNEIncrease
(local inflammation slight to moderate)


Rhino Mouse Acne model / Detailed protocol

Rhino Mouse Acne Model ImavitaMutant strain RHJ/LeJ Homozygous for Hrrh-J / JAX stock #001591

Age: Supplier dependent (generally from 8 to 12 weeks)

Gender: M and/or F / Supplier dependent

Randomization on age + gender at reception


Intradermal Acne ImavitaApplication of dermatological pharmaceutical products

Ready to use formulations / Formulation screening on request

Intra-dermal route (i.e. Medical Devices or injectable drugs)

Topical route / Reference drugs: Isotretinoin or Adapalene or Bexarotene

Oral route / Reference drug: Isotretinoin

Treatment duration: 2-3 weeks


Rhino Skin Score2 Acne ImavitaEvaluation of clinical macroscopic signs

Body weight / General behavior

Skin thickness / Caliper (back skin)

Skin macroscopic description (back skin):

Scaling (skin dryness)

Erythema (skin redness)

Other macroscopic skin observations

Sebum production using sebumeter


In vivo imaging

  Macroscopical observation: Digital pictures of back skin

  Sub-macroscopical exploration: Optical Coherence Tomography (OCT) for epidermis thickness measurement


Ex vivo imaging

  Histology on back skin slices obtained from paraffin blocks or frozen blocks

  HES (Hemalun-Eosin-Safran) / Overall evaluation of efficacy (utriculi / sebaceous glands)


Ki67 staining for keratinocyte / fibroblast / sebocyte proliferation index calculation

Other stainings on request


Other ex vivo imaging techniques of interest:

  3D reconstruction of sebaceous glands for volume evaluation

  Light Sheet microscopy (in collaboration)

  MALDI imaging (in collaboration)


Samples collection and analysis

Plasma and skin sampling, sebum sampling (surface skin lipids (SSLs) analysis)

Cytokines analysis in skin extract / plasma (terminal sampling))

– Single ELISA assay (1-2 cytokines)

– Multiplexed analysis of cytokines (>2 cytokines)

Sebum lipidomics collected in vivo (repeated sampling) or at termination for evaluation sebum composition:

– Fatty acids

– Sterols

– Cholesterol

– Wax esters

– Triglycerides

– Cholesteryl esters


Rhino Mouse Acne model / Conclusion

Rhino mouse model is a first intention model, fast and reproducible.

6 animals per group are generally sufficient to underline anti-acne effect of new therapeutics (based on difference of at least 20 to 30% of utriculi surface).

This model is well adapted for anti-seborrheic new drugs testing.

Cautions to be taken on this model :

Use of previously untested excipients should be avoid as they could cause false positive, false negative or local irritation

Formulation physico-chemistry must be well known (pH, osmolarity, etc…)

Drug pharmacokinetics / ADME / transcutaneous passage should be known to optimize dosing


CIR _ Research Tax Credit Imavita

Do not hesitate to contact us if you need more information or a quotation on this model.


Bibliography of interest

  1. Seiberg, M., et al. The effects of trypsin on apoptosis, utriculi size, and skin elasticity in the Rhino mouse. J. Invest. Dermatol. 109, 370–376 (1997).
  2. Hsia, E., et al. Effects of topically applied acitretin in reconstructed human epidermis and the rhino mouse. J. Invest. Dermatol. 128, 125–30 (2008).
  3. Benavides, F., et al. The hairless mouse in skin research. J. Dermatol. Sci. 53, 10–18 (2009).
  4. Nieves, N. J., et al. Identification of a unique subset of 2-methylene-19-nor analogs of vitamin D with comedolytic activity in the rhino mouse. J. Invest. Dermatol. 130, 2359–67 (2010).