Non‐invasive transcriptomic analysis using mRNAs in skin surface lipids obtained from children with mild‐to‐moderate atopic dermatitis

Abstract

Background Specimens for analysing the molecular pathology of skin disease are generally obtained through invasive methods, such as biopsy. However, less burdensome methods are desirable for paediatric patients. We recently established a method that comprehensively analyses RNA present in sebum (skin surface lipid–RNAs: SSL‐RNAs) using a next‐generation sequencer. Using this method, biological information can be obtained from the skin in a completely non‐invasive manner. Objectives To verify the applicability of the SSL‐RNA method for analysis of paediatric skin and analyse the molecular pathology of mild‐to‐moderate atopic dermatitis (AD) in children. Methods We collected sebum specimens from the whole faces of 23 healthy children and 16 children with mild‐to‐moderate AD (eczema area and severity index (EASI) score: 5.9 ± 2.6) ranging in age from 6 months to 5 years, using an oil‐blotting film. We then extracted SSL‐RNAs from the samples and performed an AmpliSeq transcriptomic analysis. Results The expressions of genes related to keratinization (LCE, PSORS1C2, IVL and KRT17), triglyceride synthesis and storage (PLIN2, DGAT2 and CIDEA), wax synthesis (FAR2), ceramide synthesis (GBA2, SMPD3 and SPTLC3), antimicrobial peptides (DEFB1) and intercellular adhesion (CDSN), all of which are related to the skin barrier, are lower in children with AD than in healthy children. The children with AD also have higher expression of CCL17, a Th2‐cytokine and an increased Th2‐immune response as demonstrated by a gene set variation analysis. Moreover, KRT17 and CCL17 expression levels are significantly correlated with the EASI score. Conclusions Molecular changes associated with abnormal immune responses and the epidermal barrier in children with mild‐to‐moderate AD can be determined using the SSL‐RNA method. This non‐invasive method could therefore be a useful means for understanding the molecular pathology of paediatric AD.

Abnormalities of Sphingolipids Metabolic Pathways in the Pathogenesis of Psoriasis

“…The absence of MafB was related to impairment of epidermal keratinocyte differentiation [ 119 ]. On the other hand, using a non-invasive transcriptomic analysis of surface lipids, Shima and colleagues (2022) observed a lower expression of SMPD3 in children with mild-to-moderate atopic dermatitis compared with healthy children [ 120 ]. Atopic dermatitis, similar to psoriasis, is a multifactorial skin disease triggered by activation of adaptative immunity involving Th1, Th17, and Th22 cytokines pathways [ 121 , 122 ].…”

mRNAs in skin surface lipids unveiled atopic dermatitis at 1 month

“…We collected SSLs from the face and performed purification of SSL-RNAs according to previous reports with a few modifications. 12,13,19,20 Detailed methodology is shown in Appendix S1 for Methodology.…”

Prevention of atopic dermatitis in high‐risk neonates via different types of moisturizer application: A randomized, blinded, parallel, three‐group, phase II trial (PAF study)

“…Atopic dermatitis (AD) is a chronic skin disease associated with poor quality of life 1,2 . Through RNA sequencing transcriptome, enhanced immune responses and a decreased epidermal barrier were observed in children with mild‐to‐moderate AD 3,4 . The possibility of percutaneous sensitization via the inflammatory skin in AD was established on the basis of Lack's dual‐allergen‐exposure hypothesis 5 .…”

“…1,2 Through RNA sequencing transcriptome, enhanced immune responses and a decreased epidermal barrier were observed in children with mild-tomoderate AD. 3,4 The possibility of percutaneous sensitization via the inflammatory skin in AD was established on the basis of Lack's dual-allergen-exposure hypothesis. 5 Meanwhile, early-onset infant AD was positively associated with lateronset food allergy in a prospective cohort study.…”