In vivo response of GsdmA3Dfl/+ mice to topically applied anti-psoriatic agents: Effects on epidermal thickness, as determined by optical coherence tomography and H&E staining

Abstract

This study evaluated in vivo the potential of optical coherence tomography (OCT) to determine changes in thickness of the epidermis in response to the topically applied anti-psoriatics betamethasone dipropionate (BD), salicylic acid (SA) and also fish oil (FO). GsdmA3Dfl/+ mice have an inflammatory hair loss phenotype that includes hyperproliferation and epidermal thickening, hence a potential psoriasis model. Changes in epidermal thickness were evaluated over a period of 10days, with the mice treated with combined BD+SA, FO+SA and BD+FO+SA. The data were validated with conventional measurement using H&E staining coupled with microscopy. Initial baseline measurement revealed an average epidermal thickness of 26.92±1.17μm. After 10days of treatment with BD, the average epidermal thickness was reduced by 38.8% (P=0.0001), and inversely, treatment with FO resulted in an unexpected 105% increase (P=0.0001) in epidermal thickness. Combined BD+FO treatment did not cause any significant change (P=0.3755) and may further indicate opposing effects on keratinocyte proliferation. The data obtained using OCT were statistically the same as those obtained by H&E/microscopy (P=0.4325), supporting a greater role for OCT in dermatological studies, while also allowing a reduction in the number of animals used in such studies as sacrifice at individual timepoints is not necessary. © 2011 John Wiley & Sons A/S.