Lipid Differences and Related Metabolism Present on the Hand Skin Surface of Different-Aged Asiatic Females-An Untargeted Metabolomics Study

Abstract

This cross-sectional study aimed to investigate differences in skin surface lipids (SSL) and explore related metabolic pathways among females of different ages in Henan Province. Ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used to determine the lipid composition of the skin surface of 58 female volunteers who were divided into three age groups. Statistical analysis was performed using Progenesis QI, Ezinfo, and MetaboAnalyst. Multivariate and enrichment analysis were used to identify the different SSL among the groups. A total of 530 lipid entities were identified and classified into eight classes. Among these, 63 lipids were significantly different between the groups. Lower levels of glycerolipids (GLs) and sphingolipids (SPs) were observed in the middle-aged group, while higher levels of GLs were found in the elder group. GLs belonged to the largest and statistically significant enrichment of lipid metabolic pathways, and the lipid individuals enriched to the sphingoid bases metabolism were the most and statistically significant. These findings suggest that there are differences in hand SSL among females of different ages, which may be related to GLs and sphingoid bases metabolism.

Keywords: female hand; lipidomic analysis; skin surface lipids.

Figure 1

(a): Heatmap illustrating the distribution of SSL among females at different ages. (b): The relative amounts of the eight major lipids in different age groups. The sign of * indicates that the difference is statistically significant when compared with the younger group (p < 0.05). Abbreviations: STs, sterol lipids; SPs, sphingolipids; PRs, prenol lipids; GLs, glycerolipids; PKs, polyketides; FAs, fatty acids; GPs, glycerophospholipids; SLs, saccharolipids.

Figure 2

(a): PCA score of right-hand SSL among different-aged females. (b): PLS-DA score of right-hand SSL among different-aged females. RH means right hand. (c): Loading plot of selected components of right-hand SSL among different-aged females in ESI+. Data points marked by red boxes can be seen as the characteristic ions of female SSL in each age group, respectively. 1, younger group; 2, middle-aged group; 3, elder group.

Figure 3

(a): The distribution of the important individual lipid species responsible for the discrimination of samples. (b) Comparison of relative abundance of differentiated metabolites of SSL in different age groups. The sign of * indicates that the difference is statistically significant when compared with the younger group (p < 0.05).

Figure 4

(a): Heatmap illustrating the distribution of SSL among females at different ages. (b): Metabolic pathway of important individual lipids among different age groups.