Lipidomics profiling of skin surface lipids in senile pruritus

Correlation study of facial lipid profile differences and skin physiological characteristics in Chinese women aged 19-33 years

BACKGROUND

Changes in the stratum corneum (SC) lipid profiles are associated with various skin diseases. Factors, including age, ethnicity, season and anatomical location, can influence the variations in SC lipid profiles. According to reports, the facial sebum of Chinese women peaks at age 20-30, accompanied by various signs of facial ageing. No studies have investigated how facial SC lipid profiles change with age in young Chinese women.

OBJECTIVES

This study aimed to observe the differences in the facial SC lipid profiles of Chinese female volunteers aged 19-33 and determined the relationship between key lipids and physiological parameters.

METHODS

Differential lipids were detected and screened in healthy Chinese women aged 19-33 through ultra-performance liquid chromatography-mass spectrometry. The relationship between these lipids and the skin's physiological parameters was determined.

RESULTS

The facial SC lipid profiles of young Chinese women exhibited significant differences with age. The results indicated that 40 lipids increased with age, while 51 types decreased. The average chain length of diglycerides (DG), triglycerides (TG) and short-chain ceramides decreased with age, while cholesterol esters (CE) and ceramides {Cer, Cer/EODS (d19:0/18:1/O/16:0) and Cer/EOS (d28:1/12:0/O/14:0)} increased with age. Cer/EODS (d19:0/18:1/O/16:0), Cer/EOS (d28:1/12:0/O/14:0) and HexCer/NDS (d14:0/33:1) were positively correlated with trans-epidermal water loss, skin elasticity and skin brightness, while Cer/AP (t18:0/20:0) was negatively correlated with skin elasticity. This study comprehensively explains the differences in lipid profile composition and skin ageing in young populations.

CONCLUSIONS

Young Chinese women's facial skin SC lipid profiles significantly change with age. Age-related changes result in variations in DG and CE levels and changes in the chain lengths of TG and Cer. Age-related changes in Cer content affect skin barrier function, elasticity and brightness.

A nomogram to predict skin barrier dysfunction induced by mechanical irritation during skincare in hospitalized Japanese older adults

Mechanical irritation during skincare poses a risk of causing skin barrier dysfunction in older patients. Adequate skin assessment is thus required before skincare; however, no validated assessment method exists. This study developed a nomogram to predict skin barrier dysfunction induced by mechanical irritation during skincare in Japanese older patients using a subset of a randomized controlled trial dataset. The volar forearms of 149 older patients (≥65 years) underwent a mechanical irritation test. Skin barrier dysfunction was defined based on transepidermal water loss before and after the test. Candidate variables were obtained from medical records and skin assessments. We found that 26.2 % of older patients experienced skin barrier dysfunction. The nomogram, comprising chronic kidney disease, purpura, dry skin, activities of daily living, and body mass index, demonstrated satisfactory discrimination, calibration, and clinical utility. This tool serves as an innovative and validated method for skin assessment, offering the potential to prevent skin disorders and deliver tailored, high-quality skincare.

Quantitative lipidomics profiling of skin surface lipids and skin barrier function evaluation in patients with acne vulgaris

Sebum composition may be more important than amount for acne lesions, and current research on skin surface lipids (SSLs) focuses on determining their relative content. The objective of this study was to analyze the changes in the absolute content of SSLs in acne patients and their relationship with skin barrier function. To evaluate skin barrier function, transepidermal water loss (TEWL), skin moisture, sebum content, skin elasticity, and whiteness were measured, while SSL changes were investigated using LC-MS/MS. The results indicated that adult acne patients have reduced skin barrier function, as demonstrated by changes in skin moisture, sebum content, skin flexibility, and whitening. Notably, AGlcSiE, Cer, CL, Co, LPC, PA, PC, PE, PI, SM, So, SQDG, and TG were considerably enhanced in acne patients' SSLs, whereas CerG1, DG, DGDG, MGDG, PG, and phSM were decreased. Furthermore, side chain analysis showed that the ratio of linoleic acid to linolenic acid in acne patients' skin surface lipids was higher than in healthy controls, and the caprylic acid/capric acid ratio was likewise greater. The correlation study of SSLs and skin barrier function demonstrated that increasing LPC and decreasing PG are associated with skin barrier function deterioration. In conclusion, acne patients have compromised skin barrier function and altered SSL absolute content, and certain SSL species identified in this study could serve as potential targets for research into acne pathogenesis.

Lipidomic and Instrumental Evaluation of a Melatonin-Based In & Out Strategy Versus Topical Treatment in Skin Aging: A Randomized Prospective Trial

This study aimed to evaluate the efficacy of a novel "In & Out" strategy, combining topical and oral melatonin supplementation, in managing skin aging compared to topical treatment alone. A randomized, prospective study was conducted on 39 healthy females aged 55-69 years. Participants were divided into two groups: one received both the topical formula and oral melatonin supplementation (Group A), while the other received a topical melatonin-based formula (Group B). Clinical evaluations included lipidomic analysis, skin moisturization, and wrinkle depth analysis at baseline and after 84 days. The addition of oral melatonin supplementation to the topical regimen led to improvements in the skin's lipid profile and moisturization levels. These findings suggest that combining topical and oral melatonin may provide a more comprehensive approach to managing skin aging by addressing both local and systemic factors. Background/Objectives: With age, the endogenous antioxidant capacity of the skin decreases, including melatonin (Mel) synthesis. Skin aging is also associated with alterations in epidermal lipids, particularly a reduction in triglycerides and ceramides, which are essential for maintaining skin structure and hydration. The administration of exogenous melatonin could, therefore, be an effective anti-aging strategy. While some data suggest that melatonin may positively influence the lipid profile, specific data on its effects on skin aging are lacking. This study aimed to evaluate the anti-aging effects of an "In & Out" regimen consisting of a Mel-based cream and dietary supplement in comparison with topical treatment alone, focusing on clinical and lipidomic changes involved in skin homeostasis. Results: A statistically significant variation was observed in both groups compared to baseline (T0) in terms of moisturization (+23.6% in Group A, +18.3% in Group B) and wrinkle depth (-18.5% in Group A, -9.4% in Group B, p < 0.05). Both groups showed improvements in the lipid content of the skin, which typically decreases with age. The "In & Out" strategy resulted in a statistically significant increase in triacylglycerols and ceramides, key lipids that exhibit water-holding properties. Conclusions: The "In & Out" melatonin-based regimen demonstrated greater efficacy in clinical improvement and positive lipid profile modifications compared to topical treatment alone, highlighting its potential as a comprehensive anti-aging strategy.

Risk factors of skin barrier dysfunction in older adults: A systematic review

AIM

Skin barrier dysfunction can trigger various skin disorders in older adults. Skin barrier assessment is essential for nurses and caregivers to prevent skin disorders; however, the evidence available for clinical assessment is limited. This systematic review aimed to clarify the risk factors of skin barrier dysfunction in older adults.

METHODS

This review adhered to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. The four databases were searched using multiple terms related to "aged" and "skin barrier." The search was initially run on April 19, 2023, and rerun on October 12, 2023. Peer-reviewed quantitative studies in English were included, with no publication time limit being set. Two reviewers assessed the risk of bias in a blinded and independent manner using JBI tools. Owing to the heterogeneity of the results, a narrative synthesis was performed.

RESULTS

Among the database-identified 4833 studies, 20 studies were included. The extracted factors were categorized as demographic characteristics, functional characteristics, chronic diseases, nutritional status, skin condition, and environmental factors. However, owing to high risk of bias and inconsistent results across studies, only chronic kidney disease and dry skin were considered risk factors for skin barrier dysfunction in older adults.

CONCLUSIONS

Assessment of chronic kidney disease and dry skin in daily skin care may guide the development of personalized skincare programs to maintain skin integrity in older adults. Furthermore, cohort studies that consider confounding factors and the reliability of measurements are needed for an in-depth investigation into skin barrier dysfunction and more risk factors.

Positive Correlation of Triacylglycerols with Increased Chain Length and Unsaturation with ω-O-Acylceramide and Ceramide-NP as Well as Acidic pH in the Skin Surface of Healthy Korean Adults

Triacylglycerols (TG) play an important role in skin homeostasis including the synthesis of ω-O-acylceramides (acylCER) required for skin barrier formation by providing linoleic acid (C18:2n6). However, the overall relationships of TG species with various ceramides (CER) including CER-NP, the most abundant CER, ω-O-acylCER, and another acylCER, 1-O-acylCER in human SC, remain unclear. Therefore, we investigated these relationships and their influence on skin health status in healthy Korean adults. Twelve CER subclasses including two ω-O-acylCER and two 1-O-acylCER were identified with CER-NP consisting of approximately half of the total CER. The ω-O-acylCER species exhibited positive relationships with TG 52:4 and TG 54:2 containing C18:2, while interestingly, 1-O-acylCER containing ester-linked C14:0 and C16:0 demonstrated positive relationships with TG 46-50 including C14:0 and C16:0, respectively. In addition, CER-NP and CER-NH showed positive correlations with TG 52-54 containing C18:2 or C18:3. A lipid pattern with higher levels of CER including CER-NP and ω-O-acylCER with TG 54 and TG with 5-6 double bonds was related to good skin health status, especially with acidic skin pH. Collectively, TG with increased chain length and unsaturation seemed to improve CER content, and profiles such as higher acylCER and CER-NP improved skin health status by fortifying skin barrier structure.

Drug triggered pruritus, rash, papules, and blisters - is AGEP a clash of an altered sphingolipid-metabolism and lysosomotropism of drugs accumulating in the skin?

Rash, photosensitivity, erythema multiforme, and the acute generalized exanthematous pustulosis (AGEP) are relatively uncommon adverse reactions of drugs. To date, the etiology is not well understood and individual susceptibility still remains unknown. Amiodarone, chlorpromazine, amitriptyline, and trimipramine are classified lysosomotropic as well as photosensitizing, however, they fail to trigger rash and pruritic papules in all individuals. Lysosomotropism is a common charcteristic of various drugs, but independent of individuals. There is evidence that the individual ability to respond to external oxidative stress is crosslinked with the elongation of long-chain fatty acids to very long-chain fatty acids by ELOVLs. ELOVL6 and ELOVL7 are sensitive to ROS induced depletion of cellular NADPH and insufficient regeneration via the pentose phosphate pathway and mitochondrial fatty acid oxidation. Deficiency of NADPH in presence of lysosomotropic drugs promotes the synthesis of C16-ceramide in lysosomes and may contribute to emerging pruritic papules of AGEP. However, independently from a lysosomomotropic drug, severe depletion of ATP and NAD(P)H, e.g., by UV radiation or a potent photosensitizer can trigger likewise the collapse of the lysosomal transmembrane proton gradient resulting in lysosomal C16-ceramide synthesis and pruritic papules. This kind of papules are equally present in polymorphous light eruption (PMLE/PLE) and acne aestivalis (Mallorca acne). The suggested model of a compartmentalized ceramide metabolism provides a more sophisticated explanation of cutaneous drug adverse effects and the individual sensitivity to UV radiation. Parameters such as pKa and ClogP of the triggering drug, cutaneous fatty acid profile, and ceramide profile enables new concepts in risk assessment and scoring of AGEP as well as prophylaxis outcome.