Skin Surface Lipid Composition Research Articles

Lipidomic analysis of facial skin surface lipids in acne in young women.

Alterations in the secretion and composition of skin surface lipids (SSL) are closely associated with the development of acne. Lipidomics is a useful tool to analyse the SSL of different types of acne. Our previous study found that phosphatidylserine and triacylglycerols dominate SSL changes in male acne and infantile acne, respectively. However, skin surface lipids as well as specific lipids in female acne patients remain to be investigated. To analyse and compare the SSL profile of acne women and healthy women and to discuss the involvement of differential lipids in acne development. Systematic lipidomics approach (high-throughput UPLC-QTOF-MS technology in combination with multivariate data analysis methods) was used to analyse the variations of SSL between acne and healthy groups. Analysis revealed significant differences in lipid content and composition between the two groups. Further analysis showed that levels of 13 individual lipids were significantly different and followed the same trend as the main class and subclasses. The largest individual contributor to the subgroup was triglycerides (TG) and phosphatidylinositol (PI). In addition, female acne patients exhibited reduced ceramide chain length (CCL) and increased levels of unsaturated fatty acids (UFAs), The changes of CCL in female acne are identical to male acne. There was a significantly higher level of TG and PI in the SSL of female acne patients. A reduction in CCL and an increase in UFAs content might contribute to the reduced skin barrier function in acne patients. The results suggest that female acne may have different pathogenesis than male acne.

Lipidomics profiling of skin surface lipids in senile pruritus

BackgroundSenile pruritus is common, yet its etiology remains unknown. Aging-associated skin barrier defects and skin surface lipid (SSL) alterations have been postulated to play important roles in its occurrence. In the present study, the lipidomic profiles of SSLs in elderly patients were examined to better understand the potential causes of senile pruritus.MethodsTransepidermal water loss (TEWL) was evaluated to assess the skin barrier function. The Ameliorated Kawashima Itch Scale score was used to measure the pruritus severity. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and multivariate data analysis were employed to investigate SSL alterations.ResultsThe results showed that senile pruritus patients had higher TEWL values than control subjects (13.13 ± 4.28 versus 6.71 ± 2.45, p < 0.01). LC-MS/MS revealed significant differences in the lipidomic profiles and identified 81 species of SSLs that differed between the two groups. Compared with control subjects, senile pruritus patients had increased levels of ceramides (Cers), diacylglycerols, fatty acids, phosphatidylcholines, phosphatidylethanolamines, phytosphingosines, sphingosines, diacylceryl-3-O-carboxyhydroxymethylcholine, diacylglyceryl trimethylhomoserine, and unsaturated free fatty acids, but decreased levels of triacylglycerol. Cer-EOS, Cer-NDS, and Cer-NS were positively correlated with TEWL value (p < 0.05). Pruritus severity score was positively correlated with sphingomyelin, Cer-NP, Cer-AS, Cer-NDS, and Cer-NS, but negatively correlated with Cer-BS, Cer-EODS, Cer-EOS, and Cer-AP.ConclusionsThe present study indicated that patients with senile pruritus have impaired skin barrier function and altered SSL composition. Certain SSL species identified in this study may be potential targets for future studies on the pathogenesis of senile pruritus.Trial registrationPeking University International Hospital (Number: YN2018QN04; date: January 2019).

Skin surface lipidomics revealed the correlation between lipidomic profile and grade in adolescent acne.

Acne is a multifactorial skin disorder frequently observed during adolescence with different grades of severity. The crucial factors of acne are the increase of lipids secretion and the change of composition on the skin surface lipid (SSL). However, there are no studies on the changes of lipid composition and content between different grades of adolescent acne in lesional skin and nonlesionsal skin. This study was to investigate correlation in the composition of SSL and different grades in order to understand the tendency of SSL alterations in this disease for successful acne management and prevention. A powerful analytical technique, UPLC-QTOF-MS, and multivariate data analysis were used to investigate SSL variations of lipid main classes, subclasses, and species. The results indicated that sphinganine, triradylglycerols (TG), and phytosphingosine were important in adolescent acne development. The average fatty acids (FAs) chain length in patients with acne showed significantly shortened trend from mild to moderate adolescent acne. Additionally, the relative average content of TG, diglyceride (DG), FA, ceramides (Cers), and the level of unsaturated FAs significantly increased from mild to moderate adolescent acne. Interestingly, our results demonstrated that the phytosphingosine and sphinganine showed an increasing trend in mild acne groups, but decreasing trend in lesional skin of moderate group. Lipidomics analysis suggested that the variation of TG, phytosphingosine, and sphinganine was closely related to the occurrence severity of acne in adolescent.

Skin surface lipid composition in women: increased 2,3-oxidosqualene correlates with older age.

The importance of the hydrolipidic film of skin has been well documented, however, few data are available in cases of very old age. Our aim was to characterize the difference in skin surface lipid (SSL) composition between individuals of different age groups. Data were collected from the forehead of 22 young volunteers (18-24 years old) and 18 senior volunteers (70-75 years old). The amount of sebum was obtained by sebumetry. To acquire relevant information about the molecular composition of high complex mixtures, SSLs were analysed in a single run to ensure that the lipid structures remain intact, using high-temperature gas chromatography coupled with mass spectrometry. The major features associated with aged skin were documented. In aged skin, a lower sebum content was observed, together with modification of the relative SSL composition involving a significant reduction in the intensity of many components of the hydrolipidic film. In contrast, the intensity of 2,3-oxidosqualene was shown to increase with an inverse relationship between triglycerides and their hydrolytic products. These adaptations could be related to modifications of enzymatic activity.

Lipidomics analysis of facial skin surface lipids between forehead and cheek: Association between lipidome, TEWL, and pH.

Regional differences in skin characteristics are well known. Significant differences in skin physiology between the forehead and cheek have also been reported. However, there are few studies based on lipidomics at the molecular level. Additionally, there is no study focusing on the lipid profile variations of skin surface lipid (SSL) in forehead and cheek. This study analyzed the differences in facial SSL between forehead and cheek of men aged 18-25years to explain the distinct physiological parameters between forehead and cheek resulting in different skin status. Facial SSL was identified by ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-QTOF-MS). Multivariate data analysis was used to investigate the SSL difference in forehead and cheek. Significant differences in facial SSL composition were detected between the forehead and cheek. Multivariate data analysis suggested that 21 entities contributed most significantly toward the discrimination and phosphatidylserines (PS) constituted the majority of differentiating lipid species. Subsequent analysis showed a marked increase in the amounts of unsaturated and saturated free fatty acids (FFAs), and a significant increase in average FFAs chain length in the forehead as compared to that in the cheek. Phosphatidylserines exposure might be one of the most important reasons for the increased amount of forehead SSL secretion. The different FFAs chain length and FFAs content lead to altered skin barrier functions in forehead and cheek, consequently resulting in altered trans-epidermal water loss (TEWL) and pH at the two anatomical sites.

Skin surface lipid composition analysis in heathy 22-year-old females utilizing gas chromatography-mass spectrometry

Skin surface lipid composition analysis in heathy 22-year-old females utilizing gas chromatography-mass spectrometry

Influence of Hot Spring Water on Fatty Acid Composition of Skin Surface Lipids in Hairless Mouse Model of Atopic Dermatitis.

When hairless NCN24 mice with atopic dermatitis (AD) were sprayed with a petroleum-containing alkaline salt spring water rich in metaboric acid and sodium bicarbonate, AD symptoms diminished. Reversed-phase HPLC with fluorescence detection (HPLC/FD) and online MS revealed that fatty acid (FA) composition of the skin surface lipids was similar to that in non-AD mice compared with that in AD mice. Strong negative correlations were noted between the levels of total serum immunoglobulin E (IgE) and palmitoleic acid and between the levels of total serum IgE and branched-hexadecanoic acid. Conversely, a strong positive correlation was noted between the levels of total serum IgE and linoleic acid. The present study demonstrates that the petroleum-containing spring water alters the FA composition of skin surface lipids in AD mice, which can be used as an index to evaluate inflammation.

Skin lipid profiling in normal and seborrhoeic shih tzu dogs

Seborrhoea is a clinical condition resulting in excessive lipid and/or scale on the skin and is a common and important skin disease of dogs. However, there is little information on the skin surface lipid composition of dogs with seborrhoea. To compare skin surface lipid profiles in normal and seborrhoeic shih tzu dogs. Fourteen client-owned dogs (seven seborrhoeic and seven normal) were investigated. Lipids in sebaceous glands (SGs) were extracted from homogenized tissues of SG hyperplasia. Surface lipid was collected by tape stripping [stratum corneum (SC)-enriched fraction] and acetone-wetted cotton swab (acetone-extracted fraction). Lipids in SGs, SC-enriched fractions and acetone-extracted fractions were evaluated by high-performance thin-layer chromatography. Lipids in SGs mainly consisted of cholesterol esters, wax esters and triglycerides, whereas lipids in the SC-enriched fraction mainly consisted of ceramides. The acetone-extracted fraction contained a mixture of lipid classes recognized in SG- and SC-enriched fractions. In seborrhoeic dogs, concentrations of wax esters and triglycerides in the acetone-extracted fraction were significantly higher than in control dogs (P = 0.0285). Amounts of total ceramides (in micrograms) per milligram of SC were not significantly different between the two groups (P = 0.5204). Interestingly, two unknown ceramide fractions, which accounted for 20% of the total ceramides, were recognized exclusively in seborrhoeic dogs. These results provide evidence that the skin surface lipid profiles are altered in shih tzu dogs with seborrhoea.

La nebulosa el Ojo de Dios

Isotretinoin is chemically named as: (2Z, 4E, 6E, 8E)-3,7-Dimethyl-9-(2,6,6-trimethylcyclohex-1-enyl)nona-2,4,6,8-tetraenoic acid. It is an orally active retinoic acid derivative for the treatment of severe refractory nodulocystic acne. It acts primarily by reducing sebaceous gland size and sebum production, and as a result alters skin surface lipid composition. Using isotretinoin for 1–2 mg/kg/day for 3–4 months produces 60%–95% clearance of inflammatory lesions in patients with acne. Doses as low as 0.1 mg/kg/day have also proven successful in the clearance of lesions. Encouraging results have also been seen in small numbers of patients with rosacea, Side effects affecting the mucocutaneous system and raised serum triglyceride levels occur in most patients receiving isotretinoin. Isotretinoin is strictly contraindicated in women of childbearing potential. This profile discusses and explains names of isotretinoin, its physical and chemical characteristics. It also includes methods of preparation, thermal and spectral behavior, methods of analysis, and pharmacology.

Surface Lipids as Multifunctional Mediators of Skin Responses to Environmental Stimuli

Skin surface lipid (SSL) film is a mixture of sebum and keratinocyte membrane lipids, protecting skin from environment. Its composition is unique for the high percentage of long chain fatty acids, and of the polyterpenoid squalene, absent in other human tissues, and in non-human Primates sebum. Here, the still incomplete body of information on SSL as mediators of external chemical, physical, and microbial signals and stressors is revised, focusing on the central event of the continuous oxidative modification induced by the metabolic activity of residential and pathological microbial flora, natural or iatrogenic UV irradiation, exposure to chemicals and cosmetics. Once alpha-tocopherol and ubiquinol-10 antioxidant defences of SSL are overcome, oxidation of squalene and cholesterol gives rise to reactive by-products penetrating deeper into skin layers, to mediate local defensive inflammatory, photo-protective, immune reactions or, at higher concentrations, inducing local but also systemic immune depression, ultimately implicating skin cancerogenesis. Qualitative modifications of SSL represent a pathogenetic sign of diagnostic value in dermatological disorders involving altered sebum production, like pytiriasis versicolor, acne, atopic or seborrheic dermatitis, as well as photo-aging. Achievements of nutriceutical interventions aimed at restoring normal SSL composition and homeostasis are discussed, as feasible therapeutic goals and major means of photo-protection.

Quantitative evaluation of sebum lipid components with nuclear magnetic resonance

A NMR spectroscopic method is described that enables the quantitation of specific lipid classes and components, independent of fatty acid composition. We demonstrate this method for measuring cholesterol, squalene, and pools of sterol esters, wax esters (WEs), and triglyceride (TG) components in sebum and meibum. When 600 MHz NMR equipment is used in conjunction with highly sensitive cryogenically cooled probes, this method has adequate sensitivity, and for some applications, advantages over commonly used HPLC-evaporative light-scattering detection and mass spectrometry-based approaches. This method is shown to be useful for preclinical and clinical monitoring of the efficacy of sebum-reducing agents in animals and humans. In Syrian hamsters, 3% topical flutamide and 20 mg/kg oral isotretinoin reduced sterol esters by 18.7% and 30.0%, respectively, and reduced WEs by 32.9% and 31.8%, respectively, as measured in a punch biopsy of the ear. In a 72 patient clinical methodology study, the assay delivered reproducible and noninvasive measurements of WEs, cholesteryl esters, TGs, and squalene from Sebutape skin blots. The quantitative results of sebum analysis obtained by the NMR method correlate well with those obtained with HPLC-based approaches. This approach may be broadly applicable to cases in which fatty acid-independent quantification of lipid classes is desired.

Thematic review series: Skin Lipids. Sebaceous gland lipids: friend or foe?

Sebaceous glands are intriguing glands that are found throughout the human body except on the palms of the hands and soles of the feet. The true function of these glands has yet to be determined, but there are several theories, including antioxidant effects, antibacterial effects, and transport of pheromones. Sebaceous glands produce lipids that are involved in the pathogenesis of one of the most prevalent diseases of adolescence, acne. Although the majority of lipids produced by the sebaceous gland are also produced in other areas of the body, there are two that are characteristic of the sebaceous gland, wax esters and squalene. This review seeks to present an update on the physiology of the sebaceous glands, with particular emphasis on the production of sebaceous lipids.

Ion-trap tandem mass spectrometric analysis of squalene monohydroperoxide isomers in sunlight-exposed human skin

We previously discovered that squalene monohydroperoxide (SQ-OOH) was produced on human forehead skin and suggested that skin squalene (SQ) may be the principal target lipid for oxidative stress (e.g., sunlight exposure). Because of its six double bonds, SQ peroxidation can yield various positional hydroperoxide isomers. However, the structural characterization of skin SQ-OOH isomers has never been reported. Here, we prepared pure SQ-OOH isomers and developed an analytical method for SQ-OOH isomers using a quadrupole/linear ion-trap mass spectrometer (QTRAP) MS/MS system. Collision-induced dissociation produced specific fragment ions for each SQ-OOH isomer, which permitted discrimination between SQ-OOH isomers by multiple reaction monitoring (MRM). When lipid extract from human forehead skin was subjected to LC-MS/MS with MRM, individual SQ-OOH isomers could be separated and detected with a sensitivity of 0.05 ng/injection. The total concentration of SQ-OOH isomers in forehead skin was approximately 956 microg/g skin lipids, but it increased up to 2,760 microg/g skin lipids after 3 h of sunlight exposure. The LC-MS/MS method was useful for investigating the peroxidation mechanisms of SQ as well as SQ-OOH-mediated skin disorders.

Excretion rate and composition of skin surface lipids on the foreheads of adult males with type iv hyperlipoproteinemia

Most of the lipids of the skin surface come from sebaceous glands secretions, called sebum. Some of the sebum lipids are synthesized by sebaceous cells while some are reportedly derived from the plasma. Role of blood lipoproteins in sebum secretion rate and composition is unclear. To this end, excretion rate and composition of skin surface lipids of normo- and type IV hyperlipoproteinemic subjects were compared. Quantitative analysis of skin surface lipids was performed by three successive sampling on left, middle, and right zones of the forehead with a sebumeter. Skin surface lipid samples for the compositional analysis were collected from the forehead, extracted into n-hexane, and analyzed by high performance thin layer chromatography (HPTLC). HPTLC plates were scanned with a densitometer for the quantification of the lipids. Skin surface lipids from type IV hyperlipoproteinemic subjects contained higher proportion of wax ester + cholesterol ester compared with that from normolipoproteinemic subjects. However, skin surface lipid excretion rates of normo- and hyperlipoproteinemic subjects were found to be similar. Plasma lipid/lipoprotein concentration may be a determinant factor in sebum lipid composition.

Skin surface lipids in HIV-positive patients with and without seborrheic dermatitis.

Seborrheic dermatitis (SD) is a frequent complication of infection with the human immunodeficiency virus (HIV). Most studies examining the cause of SD have concentrated on the roles of Pityrosporum ovale and sebaceous lipids. Previous studies of skin surface lipid from patients with SD have produced conflicting results, with some authors reporting an abnormal lipid composition and others finding little or no abnormality. The composition of skin surface lipid was studied in 15 HIV-positive and 10 HIV-negative men with SD, in 14 HIV-positive men without SD, and in 16 unaffected controls. Total lipids were extracted from unaffected forehead skin into petroleum ether and separated into lipid classes by thin layer chromatography. The lipid classes were quantitated by densitometry after charring with sulfuric acid. Patients, HIV-positive with SD, had significantly lower proportions of free fatty acid (FFA) and higher levels of triglyceride than normal controls. Patients, HIV-positive without SD, had a significantly increased proportion of FFA compared to HIV-positive patients with SD. Patients with SD, both HIV-positive and HIV-negative, had a similar pattern of skin surface lipid. Levels of FFA were lower and those of triglyceride higher than in the patients unaffected by SD, whether HIV-positive or not. There was no significant difference found between groups in free cholesterol, wax esters, and squalene. Abnormalities of skin surface lipid composition may play a part in the development of SD in both HIV-positive and HIV-negative men.

Object oriented artificial neural networks in decision support systems for dermatological research

Dermatological disorders, although not terminal, cannot be easily treated and are generally a greater problem socially. Usually the disease is contained rather than cured and therefore relapse is a major problem. Treatment of microbial skin diseases is multi-factorial. The onset of diseases such as acne is dependent on many factors, including age, sex, sebum production and hormonal changes. Anti androgens can be as effective a treatment as anti-microbial agents: one targets the sebum, the other the organism. It is a well established fact that with a reduction in the sebum excretion rate, there is a reduction in the number of Propionibacterium acnes, (P. acnes) which correlates with an improvement in acne. It has been shown that an increase in the amount, and changes in the composition of skin surface lipids appear to be directly related to the increasing population of P. acnes around puberty. Initial research involved both collection over time and analysis of data using traditional statistical methods. Due to the large volume of sparse data it was time consuming and difficult to integrate and implement the methods to support the decision making process. This paper illustrates the value of Object- Oriented technology and Artificial Neural Networks in building clinical decision support systems to analyse skin surface lipid data from patients with lipid dependent microbial skin diseases. The paper proposes an extension to Blum's framework for analysing data and postulates an architecture for clinical decision support systems.

Analyses of skin surface lipid in patients with microbially associated skin disease.

The composition of the total skin surface lipid, free fatty acids and fatty acid of triglyceride was used in discriminant analyses to classify patients with severe acne vulgaris (AV), pityriasis versicolor (PV), seborrhoeic dermatitis (SD) and atopic dermatitis (AD). It was not possible to discriminate between the PV and SD patients but all the lipid groups gave a satisfactory separation between AV, PV + SD and AD patients. A similar separation was obtained when the sex of the patient was studied but not when both sex and disease were taken into account. The results suggest that there are fundamental differences in the composition of skin lipid between patients with microbially associated diseases, but the precise role of the organisms has not been ascertained.

Changes in Skin Surface Lipid Composition During Therapy for Severe Acne Vulgaris and Relation to Colonisation with Propionibacteria

The percentagecomposition of total skin surface lipids and the free fatty acid and triglyceride fatty acid components of skin surface lipid has been explored in two groups of patients in whom aggressive therapy of acne resulted in a decrease in both sebum excretion rate and population densities of Propionibacterium acnes . The results showed that there were significant differences between the lipid components of males and females post-therapy and, for the most efficient therapies cyproterone acetate and retinoic acid, there were significant differences pre- and post-therapy. Differences in free fatty acid composition were evident between the group of patients in whom a decrease of at least 10 2 /cm 2 P. acnes density occurred following therapy and those in whom this decrease was not achieved. It is not evident whether these changes are directly related to the activity of the skin’s microbial flora or reflect inherent changes in the composition of skin surface lipid as a result of therapy. Keywords: Skin surface lipid; Acne vulgaris; Propionibacteria.

Changes in Skin Surface Lipid Composition During Therapy for Severe Acne Vulgaris and Relation to Colonisation with Propionibacteria

Changes in Skin Surface Lipid Composition During Therapy for Severe Acne Vulgaris and Relation to Colonisation with Propionibacteria

Skin Surface Lipid Composition of Scalp in Adults Males

Skin Surface Lipid Composition of Scalp in Adults Males