Non-invasive human skin transcriptome analysis using mRNA in skin surface lipids

Abstract

Non-invasive acquisition of mRNA data from the skin would be extremely useful for understanding skin physiology and diseases. Inspired by the holocrine process, in which the sebaceous glands secrete cell contents into the sebum, we focused on the possible presence of mRNAs in skin surface lipids (SSLs). We found that measurable human mRNAs exist in SSLs, where sebum protects them from degradation by RNases. The AmpliSeq transcriptome analysis was modified to measure SSL-RNAs, and our results revealed that SSL-RNAs predominantly contained mRNAs derived from sebaceous glands, epidermis, and hair follicles. Analysis of SSL-RNAs non-invasively collected from patients with atopic dermatitis revealed significantly increased expression of inflammation-related genes and decreased expression of terminal differentiation-related genes, consistent with the results of previous reports. Further, we found that lipid synthesis-related genes were downregulated in the sebaceous glands of patients with atopic dermatitis. These results indicate that the analysis of SSL-RNAs is promising to understand the pathophysiology of skin diseases.

Non-invasive diagnostic tool for Parkinson’s disease by sebum RNA profile with machine learning

“…The SSL collection and SSL-RNA purification were performed as described previously 18 . In addition to the RNA purification method described previously, we also used the following modified method for RNA preparation during the study.…”

“…The transcriptome analysis using SSL-RNAs was performed as described previously 18 . Briefly, 1.5 µL RNA solution and an Ion AmpliSeq Transcriptome Human Gene Expression Kit (Thermo Fisher Scientific, Waltham, MA, USA) were used for the sequencing library preparation, with modified protocols.…”

“…Sebum, a major component of skin surface lipids (SSLs), is released by a holocrine mode of secretion from sebaceous gland cells releasing their cellular components 17 . Measurable quantities of human coding and non-coding RNAs are found in SSLs (SSL-RNAs) because of RNase inhibition by the surrounding lipids 18 . SSL-RNAs can be non-invasively obtained using a single oil-blotting film, and AmpliSeq, a transcriptome method that uses target sequencing of over 20,000 human transcripts, can then be applied to detect SSL-RNAs.…”

“…SSL-RNAs can be non-invasively obtained using a single oil-blotting film, and AmpliSeq, a transcriptome method that uses target sequencing of over 20,000 human transcripts, can then be applied to detect SSL-RNAs. These techniques can be used to understand the physiological state of skin 18 . For example, SSL-RNA analysis of atopic dermatitis identified genes consistent with known pathophysiology and also indicated mechanisms related to altered lipid metabolism 18 .…”

“…These techniques can be used to understand the physiological state of skin 18 . For example, SSL-RNA analysis of atopic dermatitis identified genes consistent with known pathophysiology and also indicated mechanisms related to altered lipid metabolism 18 . We therefore investigated whether the SSL-RNA transcriptome can non-invasively differentiate patients with PD from healthy controls using machine learning.…”