AQP5 regulates the proliferation and differentiation of epidermal stem cells in skin aging.

Jing Zhou,Jinyan Wu,Yabing Dong,Jianlan Liu,Ningwen Zhu,Jie Ren

doi:10.1590/1414-431x202010009

Abstract

The epidermis, the outermost layer of the skin, is the first barrier that comes into contact with the external environment. It plays an important role in resisting the invasion of harmful substances and microbial infections. The skin changes with age and external environmental factors. This study aimed to investigate epidermal stem cells during the process of aging. This study enrolled 9 volunteers with benign pigmented nevus for clinical dermatologic surgery. The phenotypes associated with skin aging changes such as skin wrinkles and elasticity of the unexposed/healthy parts near benign pigmented skin were measured, and epidermal stem cells from this region were isolated for transcriptome sequencing. The results showed that epidermal stem cells could be obtained by magnetic activated cell sorting (MACS) with high purity. Results of the transcriptome sequencing revealed that aquaporin (AQP)5 significantly decreased in the epidermal stem cells with age, and further functional experiments revealed that AQP5 could promote the proliferation and dedifferentiation of HaCaT, but did not influence cell apoptosis. In summary, AQP5 regulated the proliferation and differentiation of epidermal stem cells in skin aging, and it may play an important role in the balance of proliferation and differentiation. However, further studies are needed to determine the mechanism by which AQP5 regulates the proliferation and differentiation of epidermal skin cells in aging.

Highlights

The skin is the outmost barrier and is the organ with the largest surface area of the body
Skin aging phenotype in young and elderly groups To investigate the effect of age on skin phenotypes and epidermal stem cells, we divided the sample into two group: young group (YG, p40 years) and elderly group (EG, X41 years)
The number (Figure 1B) and depth (Figure 1D) of wrinkles increased with age, and there was a significant difference in the number of wrinkles (Figure 1C) and depth (Figure 1E) between the YG and EG, indicating that skin wrinkles increase, deepen, and become rough with age

Summary

Introduction

The skin is the outmost barrier and is the organ with the largest surface area of the body. With age, symptoms of aging gradually appear on the skin, such as wrinkles, thinning, and relaxation changes [1,2]; there are changes in tissue structure (epidermal atrophy and epidermal cell layer reduction), and physiological function degradation and loss [3] Together with these symptoms, the skin’s reactivity is weakened, reducing its defense against mechanical and chemical damage, microbial invasion, and regenerative healing ability, leading to a series of skin-related diseases [4,5,6]. Epidermal stem cells (ESCs), which are located in the basal layer of the epidermis, have the ability of lifelong self-renewal, can maintain a constant number through division, while continuing to differentiate into various layers of skin tissue. Wnt induces the hyperproliferation of hair follicle cells and the rapid exhaustion of stem cells [9], and p16INK4a governs the processes of stem cell self-renewal by inhibiting the G1/Sphase transition of the cell cycle [10]

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