An innovative trio strategy for maintaining skin hydration homeostasis
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Presented by: Yicheng Xu
Introduction: Skin hydration is one of the basic requirements in the field of skin care. Maintenance of skin water balance is essential for cutaneous cells and barrier functions. Various environmental and physiological factors may contribute to the heterogeneity of skin dryness. The skin hydration strategies for different skin layers also need to be specific. Recent evidence has shown that crosstalk between cells from different skin layers is critical for maintaining overall skin homeostasis. Therefore, a multi-layered hydration strategy seems to be particularly important to deal with the skin of different dehydration states under the exposome. The purpose of this study is to investigate a three-in-one strategy of the stratum corneum, epidermis and dermis to maintain skin hydration homeostasis.
Methods: We first investigated the water balance improvement of the outer layers of the skin. Human primary keratinocytes (NHEKs) were obtained from a mature female donor. At the end of the 48 hours incubation, intracellular bleomycin hydrolase (BLMH) was quantified in cell lysates. In order to mimic the osmoregulatory processes under dehydration stress, NHEKs were placed in a hyperosmotic medium. At the end of the 72 hours incubation, intracellular taurine levels were measured in cell lysates. Next, hyaluronic acid production levels in human primary fibroblasts (NHDFs) were measured after 48 hours incubation.
Results: In NHEKs, the BLMH synthesis was significantly increased dose-dependently by a novel hydration agent, which was more efficient than CaCl2. Under hyperosmotic condition, this hydration agent up-regulated significantly, in a dose-dependent manner, intracellular accumulation of taurine in NHEKs, with efficacy similar to hypotaurine. The same increasing trend of hyaluronic acid (HA) production in NHDFs was observed under the action of the novel hydration agent.
Discussion & Conclusion: BLMH is considered to be essential for the complete degradation of filaggrin into free amino acids, the latter act as NMFs in the upper stratum corneum. Studies have shown that the decreased expression of BLMH causes the low hydration state of dry skin. In addition to its hydration function, recent evidence indicates that this protease can also regulate the levels of several key chemokines involved in epidermal inflammation and wound healing. BLMH is critical for skin barrier function and upper skin hydration. For many dry skin conditions, keratinocytes may be exposed to hyperosmotic stress. Intracellular accumulation of taurine protects keratinocytes from osmotically and UV-induced damages by maintaining cellular water balance and survival. Taurine has also been shown to have antioxidant, anti-inflammatory and membrane stabilizing activities. Dermal HA plays a multifaceted role in modulating various biological processes, its water holding ability results in softer, smoother and more radiant skin. These have been confirmed in clinical trials. The increase in epidermal BLMH biosynthesis, intracellular taurine accumulation and dermal HA production address multi-layered hydration, this trio strategy may represent a new approach for maintaining skin hydration homeostasis.
Methods: We first investigated the water balance improvement of the outer layers of the skin. Human primary keratinocytes (NHEKs) were obtained from a mature female donor. At the end of the 48 hours incubation, intracellular bleomycin hydrolase (BLMH) was quantified in cell lysates. In order to mimic the osmoregulatory processes under dehydration stress, NHEKs were placed in a hyperosmotic medium. At the end of the 72 hours incubation, intracellular taurine levels were measured in cell lysates. Next, hyaluronic acid production levels in human primary fibroblasts (NHDFs) were measured after 48 hours incubation.
Results: In NHEKs, the BLMH synthesis was significantly increased dose-dependently by a novel hydration agent, which was more efficient than CaCl2. Under hyperosmotic condition, this hydration agent up-regulated significantly, in a dose-dependent manner, intracellular accumulation of taurine in NHEKs, with efficacy similar to hypotaurine. The same increasing trend of hyaluronic acid (HA) production in NHDFs was observed under the action of the novel hydration agent.
Discussion & Conclusion: BLMH is considered to be essential for the complete degradation of filaggrin into free amino acids, the latter act as NMFs in the upper stratum corneum. Studies have shown that the decreased expression of BLMH causes the low hydration state of dry skin. In addition to its hydration function, recent evidence indicates that this protease can also regulate the levels of several key chemokines involved in epidermal inflammation and wound healing. BLMH is critical for skin barrier function and upper skin hydration. For many dry skin conditions, keratinocytes may be exposed to hyperosmotic stress. Intracellular accumulation of taurine protects keratinocytes from osmotically and UV-induced damages by maintaining cellular water balance and survival. Taurine has also been shown to have antioxidant, anti-inflammatory and membrane stabilizing activities. Dermal HA plays a multifaceted role in modulating various biological processes, its water holding ability results in softer, smoother and more radiant skin. These have been confirmed in clinical trials. The increase in epidermal BLMH biosynthesis, intracellular taurine accumulation and dermal HA production address multi-layered hydration, this trio strategy may represent a new approach for maintaining skin hydration homeostasis.