Natural Moisturizing Factor Research Articles

고농도의 미네랄을 실리콘 네트워크 필름에 포집한 젤 에센스 제형의 피부 밝기 개선 효과

Since minerals are in ionic forms in aqueous phase (like deep sea water), it is very hard to incorporate concentrated minerals in gel like cosmetic formulations which are generally composed of carbomer or acrylates polymer. In this study, we invented a salt-resistant network formulation made of silicon copolyol. It was found that the network formulation traps minerals (especially from marine) in a mesh-like silicone copolyol structure. Since the mineral-containing formulation makes a very thin film on the skin, minerals could be easily absorbed into stratum corneum. In 6 weeks in vivo test, it was found that the novel mineral formulation increased the amounts of amino acids, major components of natural moisturizing factors (NMFs), as well as levels of minerals. It was also found that the moisture contents and the brightness of the skin increased.

Impact of filaggrin mutations on Raman spectra and biophysical properties of the stratum corneum in mild to moderate atopic dermatitis

Atopic dermatitis (AD) is associated with null mutations in the filaggrin (FLG) gene. To assess the impact of FLG null mutations on biophysical properties and the molecular composition of the stratum corneum (SC) in healthy individuals and AD patients. A total of 196 French adults, including 97 with a history of mild to moderate AD, were genotyped for the three major European FLG mutations. Components of the natural moisturizing factor (NMF), lipids and water content in the SC were determined using Raman spectroscopy. In addition, trans-epidermal water loss, capacitance and pH of the SC were measured. Stratum corneum concentrations of total NMF, water, ornithine and urocanic acid (UCA) were significantly lower in AD patients than in healthy controls. Null mutations of FLG were detected in 4% of controls and 10% of AD patients. FLG mutations were associated with increased SC levels of lactate, reduced concentrations of most other NMF components and higher disease severity in AD patients. In AD patients without FLG mutations, the content of NMF constituents decreased with increasing disease severity. The concomittant presence of low concentrations of histidine, alanine and either glycine or pyrrolidone-5-carboxylic acid (PCA) in the SC was associated with FLG mutations with 92% specificity. Our findings suggest a low prevalence of FLG mutations in mild AD and support an important role for filaggrin in determining the physicochemical parameters of the SC. The combined measurement of several filaggrin breakdown products in the SC may be useful to specifically predict the presence of FLG mutations.

Hydrating effect of potassium lactate is caused by increasing the interaction between water molecules and the serine residue of the stratum corneum protein

Natural moisturizing factors (NMFs) play an important role in maintaining the physical properties of the stratum corneum (SC). The relationship between SC water content and NMFs has long been investigated. Recently, we demonstrated that potassium lactate as an NMF increased SC water content more than sodium lactate did. The details of the moisturizing mechanism of NMFs, however, were not revealed. We, therefore, investigated the cause of the SC moisturizing effect of potassium lactate in comparison with sodium lactate. Using differential scanning calorimetry, we found that potassium lactate increased the bound water content of plantar SC more than what sodium lactate did. We also found, however, that the bound water content of the potassium lactate solution was less than that of the sodium lactate solution, suggesting that potassium lactate increased the water molecules interacting with SC components. Moreover, potassium lactate increased the ratio of hydrogen/deuterium exchange at 1340/cm, which represents the OH bending mode, of plantar SC spectra obtained by the attenuated total reflectance infrared spectroscopy. We assign this band to the OH group of the serine residue. These results suggest that potassium lactate increases the water-holding capacity of the SC by increasing interaction between water molecules and the OH group of serine in SC keratin.

Interleukin-22 downregulates filaggrin expression and affects expression of profilaggrin processing enzymes

The identification of filaggrin mutations has contributed towards our understanding of hereditary factors associated with epidermal dysfunction observed in individuals with atopic eczema (AE). However, factors that predispose to acquired filaggrin modulation are not well understood. Interleukin (IL)-22 is upregulated in lesional AE tissue, but its effects on filaggrin expression and genes associated with epidermal function have not yet been comprehensively addressed. To investigate the effects of IL-22 on expression of filaggrin and genes encoding proteins relevant to epidermal function. Microarray analysis was performed on IL-22-stimulated HaCaT keratinocytes. Filaggrin protein level was assessed by an intracellular enzyme-linked immunosorbent assay (ELISA) and Western blot in HaCaT cells and the findings were validated in primary keratinocytes. Exposure to IL-22 cytokine resulted in a downregulation of profilaggrin mRNA expression in HaCaT keratinocytes. The expression of genes involved in enzymatic processing of profilaggrin as well as the generation of natural moisturizing factor was also altered. Furthermore, there was an upregulation of many transcripts encoding proteins of the S100 family. Profilaggrin/filaggrin downregulation was detected by intracellular ELISA and Western blot in HaCaT cells. The relevance to the primary setting was confirmed in primary keratinocytes by Western blot. IL-22 downregulates profilaggrin/filaggrin expression in keratinocytes at both mRNA and protein levels and affects genes relevant to epidermal function. This novel pathway may have relevance to the pathogenesis and treatment of atopic and other skin disease.

Regulation of caspase 14 expression in keratinocytes by inflammatory cytokines - a possible link between reduced skin barrier function and inflammation?

Caspase 14 is a unique member of the cysteinyl aspartate-specific proteinase family. Its expression is confined primarily to cornified epithelium such as the skin. Caspase 14 has been associated with the processing of filaggrin monomers and the development of natural moisturising factors of the skin, and thus, it could be speculated that caspase 14 dysregulation is implicated in the development of an impaired skin barrier function. We have investigated the regulation of caspase 14 transcription in cultured primary keratinocytes following stimulation with a number of factors present in inflamed skin, including T(H)1- and T(H)2-associated cytokines in addition to LPS and peptidoglycan. In particular, we found that T(H)2-associated cytokines reduced the caspase 14 mRNA level significantly. Furthermore, we found that the expression of caspase 14 was reduced in skin biopsies from patients with atopic dermatitis (AD), psoriasis and contact dermatitis, further supporting a role for this kinase in inflammatory skin conditions. Hence, the regulation of caspase 14 levels provides a possible link between impaired skin barrier function and inflammatory reactions in skin diseases such as AD and may offer an explanation to the skin barrier dysfunction in inflamed skin lesions.

Dietary Pocheon royal jelly recovers epidermal hydration with the increased generation of ceramide 1 and 2 from glucosylceramides in UV irradiated hairless mouse

Ultraviolet (UV) irradiation induces skin dryness, largely by disruption of epidermal barrier. In search for dietary sources that would protect against skin dryness, we investigated the dietary effect of royal jelly (RJ) on epidermal levels of hydration and ceramides, the major lipid maintaining epidermal barrier. Hairless mice were fed diets of either control (group UV), or diets containing 1% RJ harvested from Cheolwon (group CW), Pocheon (group PC) in Korea or imported from China (group CH) for 6 wks in parallel with UV irradiation. Epidermal hydration of group PC was significantly higher than of group UV. In parallel, epidermal levels of ceramides (cer), specifically cer 1 and 2 as well as glucosylceramides (GC) were higher than in group UV. Furthermore, protein expression of ¥â‐glucocerebrosidase (¥â‐GlcCer¡̄ase), an enzyme of generating Cer from GC, in group PC was higher than in group UV. In spite of increased levels of Cer 1, 2, GC and ¥â‐GlcCer¡̄ase protein, epidermal hydration of group CW was at the similar level to group UV. There was no difference of these parameters between groups CH and UV. Dietary supplementation of Pocheon RJ protects skin from UV‐induced dryness with an accumulation of ceramides, specifically ceramide 1 and 2 due to elevated ¥â‐GlcCer¡̄ase expression. Cheolwon RJ might alter other factors influencing skin dryness such as natural moisturizing factors.

Bleomycin Hydrolase Is Regulated Biphasically in a Differentiation- and Cytokine-dependent Manner: RELEVANCE TO ATOPIC DERMATITIS

Loss-of-function mutation in the profilaggrin gene is a major risk factor for atopic dermatitis (AD). Previously, we showed that a neutral cysteine protease, bleomycin hydrolase (BH), has a role in generating natural moisturizing factors, and calpain I is an upstream protease in the filaggrin degradation pathway. Here, we investigated the transcriptional regulatory mechanisms of BH and the relevance of BH to AD. First, we cloned the 5'-flanking region of BH. Deletion analyses identified a critical region for BH promoter activity within -216 bp upstream. Electrophoretic mobility shift assay revealed that MZF-1, Sp-1, and interferon regulatory factor-1/2 could bind to this region in vitro. Moreover, site-directed mutagenesis of the MZF-1 and Sp-1 motifs markedly reduced BH promoter activity. These data indicate that BH expression is up-regulated via MZF-1 and Sp-1. Interestingly, a Th1 cytokine, IFN-γ, significantly reduced the expression of BH. Analyses with site-directed mutagenesis and small interference RNA supported the suppressing effect of IFN-γ on BH expression. On the other hand, a Th2 cytokine, IL-4, did not show any direct effect on BH expression. However, it down-regulated MZF-1 and Sp-1 in cultured keratinocytes, indicating that IL-4 could work as a suppressor in BH regulation. Lastly, we examined expression of BH in skins of patients with AD. BH activity and expression were markedly decreased in AD lesional skin, suggesting a defect of the filaggrin degradation pathway in AD. Our results suggest that BH transcription would be modulated during both differentiation and inflammation.

Characterizing the composition of underarm and forearm skin using confocal raman spectrscopy

Many studies have reported differences in skin composition as a function of body site and age. However, rarely has axilla (underarm) skin been included in these studies. This report highlights the results of a clinical study where confocal Raman spectroscopy was used to assess the differences between underarm and volar forearm skin. In the reported study, the concentration of natural moisturizing factor (NMF), urea, lactic acid, cholesterol, trans urocanic acid (t-UCA) and ceramide 3 (N-octadecanoyl-phytosphingosine) was evaluated as a function of depth, body site (underarm vs. forearm) and age. Two age groups of women were included: (i) between 20 and 30 years and (ii) older than 55 years (post-menopause). The levels of cholesterol, ceramide 3 and lactic acid were highest in the underarm regardless of the age group whereas the forearm contained higher amounts of NMF. Ceramide 3, urea and lactic acid were significantly lower for women 55 years or older in the underarm. No age-related differences were detected within the forearm site..

Levels of filaggrin degradation products are influenced by both filaggrin genotype and atopic dermatitis severity

Background:Filaggrin, coded by FLG, is the main source of several major components of natural moisturizing factor (NMF) in the stratum corneum (SC), including pyrrolidone carboxylic acid (PCA) and urocanic acid (UCA). Loss-offunction mutations in FLG lead to reduced levels of filaggrin degradation products in the SC. It has recently been suggested that expression of filaggrin may additionally be influenced by the atopic inflammatory response. In this study, we investigated the levels of several breakdown products of filaggrin in the SC in healthy controls (CTRL) and patients with atopic dermatitis (AD) in relation to FLG null allele status. We examined the relationship between NMF (defined here as the sum of PCA and UCA) and AD severity.Methods:The SC levels of filaggrin degradation products including PCA, UCA, histidine (HIS) and tyrosine were determined in 24 CTRL and 96 patients with moderate-to-severe AD. All subjects were screened for 11 FLG mutations relevant for the study population.Results:The levels of PCA, UCA and HIS correlated with FLG genotype. Furthermore, these levels were higher in the CTRL when compared to AD patients with no FLG mutations. Multiple regression analysis showed that NMF levels were independently associated with FLG genotype and severity of disease.Conclusion:Decreased NMF is a global feature of moderate-to-severe AD; within AD, FLG genotype is the major determinant of NMF, with disease severity as a secondary modifier. NMF components are reliably determined by a noninvasive and relatively inexpensive tape stripping technique.

Comparative proteomic profiling of patients with atopic dermatitis based on history of eczema herpeticum infection and Staphylococcus aureus colonization

Atopic dermatitis (AD) is the most common inflammatory skin disorder in the general population worldwide, and the majority of patients are colonized with Staphylococcus aureus. Eczema herpeticum is a disseminated herpes simplex virus infection that occurs in a small subset of patients. The goal was to conduct proteomic profiling of patients with AD based on S. aureus colonization status and history of eczema herpeticum. We hoped to identify new biomarkers for improved diagnosis and prediction of eczema herpeticum and S. aureus susceptibility and to generate new hypotheses regarding disease pathogenesis. Skin taping was performed on nonlesional skin of nonatopic control subjects and on lesional and nonlesional skin of patients with AD. Subjects were classified according to the history of eczema herpeticum and S. aureus colonization. Proteins were analyzed by using mass spectrometry; diagnostic groups were compared for statistically significant differences in protein expression. Proteins related to the skin barrier (filaggrin-2, corneodesmosin, desmoglein-1, desmocollin-1, and transglutaminase-3) and generation of natural moisturizing factor (arginase-1, caspase-14, and gamma-glutamyl cyclotransferase) were expressed at significantly lower levels in lesional versus nonlesional sites of patients with AD with and without history of eczema herpeticum; epidermal fatty acid-binding protein was expressed at significantly higher levels in patients with methicillin-resistant S. aureus. This noninvasive, semiquantitative profiling method has revealed novel proteins likely involved in the pathogenesis of AD. The lower expression of skin barrier proteins and enzymes involved in the generation of the natural moisturizing factor could further exacerbate barrier defects and perpetuate water loss from the skin. The greater expression of epidermal fatty acid-binding protein, especially in patients colonized with methicillin-resistant S. aureus, might perpetuate the inflammatory response through eicosanoid signaling.

Natural moisturizing factor components in the stratum corneum as biomarkers of filaggrin genotype: evaluation of minimally invasive methods

Natural moisturizing factor components in the stratum corneum as biomarkers of filaggrin genotype: evaluation of minimally invasive methods

Abstracts: Ultra low viscosity emulsion with high tolerance for electrolytes

pp.34–40 Among many useful functions of modern skin‐care products, moisturizing effect is the most fundamental and important. The ‘moisture‐balance concept’ which emphasizes the balance of lipid, Natural Moisturizing Factors (NMFs) and water is a key to improving skin condition. Many skin‐care products incorporating lipid and NMF have appeared on the market. However, since NMFs are electrolytes, their presence tends to cause lipid droplets to aggregate and seriously compromise the emulsion stability. Consequently, it has been practically impossible to incorporate both NMFs and lipids into ultra low viscosity products such as toning lotions, which limits their applications. We investigated certain biogenic materials capable of emulsifying lipid in vivo in the presence of electrolytes, including lecithins which have a high affinity for human skin. Our results showed that lysolecithin has high tolerance for electrolytes and high affinity for skin. We developed a novel emulsification technology using lysolecithin. Moreover, we successfully prepared a toning lotion, ‘Biomimetic Moisturizer,’ incorporating both lipids and NMFs, using this technology, and demonstrated its high moisturizing effect and efficacy in improving skin condition.

Abstracts: Natural moisturizing factors in the stratum corneum II. Regeneration of NMF over time after soaking

pp. 23–29 The detrimental effects of prolonged water exposure on skin are well known. Information on the effects of short‐term exposure, e.g. during bathing, showering, and hand washing, on Natural moisturizing factors (NMF) levels is limited. In an attempt to isolate the effects of soaking on the NMF, a time course for skin sample collection was devised in which adhesive tapes were applied 0.5 and 4 h after soaking of the treated arm. Significant decreases in NMF levels, quantified by high‐performance liquid chromatography analysis of serial tape strips, were observed 0.5 h after soaking, with a replacement of NMF occurring by the four‐hour mark. This replacement corresponds to a parallel rebound in skin pH also observed at these times. Stratum corneum (SC) hydration values, measured instrumentally as the rate of moisture accumulation (MAT), however, were depressed 0.5 h post‐soaking and remained low 4 h later. In addition, significant increases in skin pH were observed during the immediate post‐soak period. These findings suggest that short‐term exposure to water alone produces significant changes in the SC.

Abstracts: Natural moisturizing factors in the stratum corneum I. Effects of lipid extraction and soaking

pp. 13–22 Natural moisturizing factor (NMF) is essential for appropriate stratum corneum hydration, barrier homeostasis, desquamation, and plasticity. It is formed from filaggrin proteolysis to small, hygroscopic molecules including amino acids. We hypothesized that common lipid extraction and soaking in water would alter the level of NMF in the upper stratum corneum (SC) and its biophysical properties. A novel method of measuring and quantifying the amino acid components of NMF is presented. Adhesive tapes were used to collect samples of the SC and were extracted with 6 mM perchloric acid for analysis by reverse‐phase high‐performance liquid chromatography (HPLC).The HPLC results were standardized to the amount of protein removed by the tapes. An increase in NMF was found with increased SC depth. Also, the combination of extraction and soaking was found to increase NMF loss relative to control or to extraction or soaking alone. Our results indicate that common skin care practices significantly influence the water binding materials in the upper SC. The findings have implications for the evaluation and formulation of skin care products.

Infant skin physiology and development during the first years of life: a review of recent findings based on in vivo studies

Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin it seems to be more prone to develop certain pathological conditions, such as atopic dermatitis and irritant contact dermatitis. Therefore, understanding the physiology of healthy infant skin as a point of reference is of interest both from the cosmetic as well as from the clinical point of view. Clinical research on healthy infants is, however, limited because of ethical considerations of using invasive methods and therefore until recently data has been scarce. Technical innovations and the availability of non-invasive in vivo techniques, such as evaporimetry, electrical impedance measurement, in vivo video and confocal microscopy, and in vivo fibre-optic based spectroscopy, opened up the field of in vivo infant skin physiology research. Studies incorporating such methods have demonstrated that compared to adult, infant skin continues to develop during the first years of life. Specifically, infant skin appears to have thinner epidermis and stratum corneum (SC) as well as smaller corneocytes at least until the second year of life. The water-handling properties are not fully developed before the end of the first year and infant SC contains more water and less amounts of natural moisturizing factors. Such findings re-evaluate the old notions that skin is fully matured at birth. Armed with this knowledge, we are in a position not only to better understand infant dermatological conditions but also to design better skin care products respecting the distinct qualities of infant skin.

Raman profiles of the stratum corneum define 3 filaggrin genotype–determined atopic dermatitis endophenotypes

BackgroundFilaggrin (FLG) has a central role in the pathogenesis of atopic dermatitis (AD). FLG is a complex repetitive gene; highly population-specific mutations and multiple rare mutations make routine genotyping complex. Furthermore, the mechanistic pathways through which mutations in FLG predispose to AD are unclear.ObjectivesWe sought to determine whether specific Raman microspectroscopic natural moisturizing factor (NMF) signatures of the stratum corneum could be used as markers of FLG genotype in patients with moderate-to-severe AD.MethodsThe composition and function of the stratum corneum in 132 well-characterized patients with moderate-to-severe AD were assessed by means of confocal Raman microspectroscopy and measurement of transepidermal water loss (TEWL). These parameters were compared with FLG genotype and clinical assessment.ResultsThree subpopulations closely corresponding with FLG genotype were identified by using Raman spectroscopy. The Raman signature of NMF discriminated between FLG-associated AD and non–FLG-associated AD (area under the curve, 0.94; 95% CI, 0.91-0.99). In addition, within the subset of FLG-associated AD, NMF distinguished between patients with 1 versus 2 mutations. Five novel FLG mutations were found on rescreening outlying patients with Raman signatures suggestive of undetected mutations (R3418X, G1138X, S1040X, 10085delC, and L2933X). TEWL did not associate with FLG genotype subgroups.ConclusionsRaman spectroscopy permits rapid and highly accurate stratification of FLG-associated AD. FLG mutations do not influence TEWL within established moderate-to-severe AD.

Recent advances in skin ‘barrier’ research

Our knowledge on the complexity of stratum corneum biology, chemistry and biophysics has grown over the last decade. This and the intricate control mechanisms in the stratum corneum that bring about its full and proper structural maturity will be reviewed. The importance of the total architecture of the stratum corneum in relation to desquamation and barrier function, the role of the corneodesmosomes and their degrading enzymes, new insights into the importance of natural moisturising factor and the emerging knowledge on the chemical antimicrobial barrier of the stratum corneum are discussed. Despite our increasing knowledge of the complexity of stratum corneum, we are still far from understanding its intricate control mechanisms that bring about its maturity and desquamation.

Generation of Human Skin Equivalents Under Submerged Conditions—Mimicking theIn UteroEnvironment

In this study we generated human skin equivalents (HSEs) under submerged conditions mimicking the aqueous in utero environment and investigated the morphology and differentiation process of the formed epidermis. Further, the skin barrier, which resides in the stratum corneum (SC), was characterized by its lipid content, hydration level, and natural moisturizing factor level. The submerged HSEs showed comparable tissue morphology and similar expression of several differentiation markers and SC lipid composition compared with HSEs grown at the air-liquid interface and native human skin. The SC of the submerged HSEs, however, contained more free water and less natural moisturizing factors compared with the air-exposed counterparts. These results show that the presented cell culture method can be utilized to generate HSEs under submerged conditions to study epidermal formation under aqueous conditions.

Effects of glycerol on human skin damaged by acute sodium lauryl sulphate treatment

Glycerol, widely used as humectant, is known to protect against irritants and to accelerate recovery of irritated skin. However, most studies were done with topical formulations (i.e. emulsions) containing glycerol in relatively high amounts, preventing drawing conclusions from direct effects. In this study, acute chemical irritations were performed on the forearm with application of a 10% sodium lauryl sulphate (SLS) aqueous solution under occlusion for 3 h. Then, glycerol aqueous solutions from 1 to 10% were applied under occlusion for 3 h. After elimination of moist excess consecutive to occlusive condition, in ambient air for 15 and 30 min, skin barrier function was investigated by dual measurement of skin hydration and transepidermal water loss (TEWL). Treatments with SLS solution under occlusion significantly increased TEWL and decreased skin hydration as assessed by capacitance measurements. The SLS irritant property was raised by the occlusion and the water barrier function as well as water content appeared impaired. Recovery with glycerol at low doses was remarkable through a mechanism that implies its hygroscopic properties and which is saturable. This precocious effect acts through skin rehydration by enhancing water-holding capacity of stratum corneum that would facilitate the late physiological repair of impaired skin barrier. Thus, glycerol appears to substitute for natural moisturizing factors that have been washed out by the detergent action of SLS, enhancing skin hydration but without restoring skin barrier function as depicted by TEWL values that remained high. Thus, irritant contact dermatitis treated with glycerol application compensate for skin dehydration, favouring physiological process to restore water barrier function of the impaired skin. Empirical use of glycerol added topical formulations onto detergent altered skin was substantiated in the present physicochemical approach.

Pruritus and dryness of the skin in chronic kidney insufficiency and dialysis patients – a review

The uremic pruritus is a very painful symptom suffered by chronic haemodialysis patients and is observed in 22 to 74% of the subjects. The causes of uremic pruritus have not yet been clarified. During the last 20 to 30 years it has been focused on altogether 5 different pathophysiological hypotheses: stimulating influences (e.g. calcium phosphate deposits in the epidermis), stimuli (e.g. secondary hyperparathyroidism), neuropathic injuries (e.g. disturbance of the cutaneous innervation in patients with uremic peripheral neuropathy), and central nervous changes (e.g. accumulation of endorphins in uremic patients which is associated with increasing pruritus), and immunologic conditions. The last mentioned immunological hypothesis has increasing importance, not at least based on the fact that the application of a topical calcineurin inhibitor (tacrolimus) improves the uremic pruritus. However, this fact could not be confirmed in a recent prospective placebo-controlled study from the USA. Only after kidney transplantation with a functioning transplant the uremic pruritus is stopped. That is why no causal therapy exists so far. Actually, the uremic pruritus has to be treated by topical and systemic means in a symptomatic and polypragmatic way only. Urea represents one of the most important "natural moisturizing factors" which are responsible for the hydration of the skin. It has been demonstrated that older patients have decreased urea levels within the stratum corneum of the epidermis, whereas in patients with terminal kidney insufficiency - despite dryness of the skin - as a paradox finding elevated levels of urea have been assessed in the stratum corneum. Because of this reason, the meaning of urea as part of the "natural moisturizing factors" system is not understood, until now. However, there are very promising results of clinical phase II studies showing a significant effect of topical application of 2.5% L-arginine hydrochlorid ointment - a semi-essential amino acid - on improvement of dryness and, in particular, on improvement of pruritus in haemodialysis patients.