Similarity of Expression Patterns Between Facial and
Scalp Skin Surface Lipids RNA Is Confirmed

Kao discovered the presence of human RNA in sebum in 2019, and developed SSL-RNA monitoring technology, a non-invasive method for comprehensive analysis of RNA extracted from facial sebum collected using an oil blotting film. Furthermore, the SSL-RNA expression profiles revealed that the facial skin can be classified into at least two skin types^*2 , one type characterized by high expression of genes involved in skin barrier functions such as “keratinization”, and the other type characterized by high expression of genes involved in skin immune functions such as “immune response”.
Until now, Kao has primarily accumulated knowledge based on facial SSL-RNA; however, SSL-RNA can also be obtained from the scalp. In terms of basic structure and function, the scalp has much in common with the face, but no detailed analysis has yet been undertaken.
Kao has now utilized this technology to analyze SSL-RNA expression profiles from the face and scalp of the same individuals.

SSL-RNA was sampled simultaneously from the face and scalp of 33 Japanese women^*3 , and the average expression levels of each of the approximately 20,000 RNA species obtained were calculated for each site. The similarity between the RNA expression profiles of the two sites was evaluated using Spearman’s rank correlation, and the results showed a very strong correlation (Figure 1). This result indicates that the expression patterns —which RNA have relatively high (or low) expression—of the face and scalp are similar.

Kao has discovered that the expression patterns of facial and scalp SSL-RNA are similar. Kao has already developed “skin gene mode determination” technology that uses SSL-RNA expression information to estimate skin type from facial images^*4 . Kao will further explore the application of the skin gene mode to the scalp.

Kao, a Japan-based manufacturer of personal care and household products, cosmetics, and specialty chemicals creates high-value-added products and services that provide care and enrichment for the life of all people and the planet. Through its brands such as Attack laundry detergent, Bioré and Jergens skin care products, Laurier sanitary products, Curél, SENSAI, and MOLTON BROWN cosmetics, and Oribe hair care products, Kao is part of the everyday lives of people across Asia, the Americas, Europe, the Middle East, and Africa. Combined with its chemical business, which contributes to a wide range of industries, Kao generates about 1,630 billion yen in annual sales. Kao employs about 32,600 people worldwide and has more than 130 years of history in innovation. As an enterprise that provides products people use on a daily basis, the Kao Group takes responsibility to actively reduce the environmental footprint of its products throughout the product lifecycle. This is laid out in Kao’s ESG strategy, the Kirei Lifestyle Plan, which launched in 2019.
Please visit the Kao Group website for additional information.