Effect of estrogen/progesterone ratio on the differentiation and the barrier function of epidermal keratinocyte and three-dimensional cultured human epidermis

A Consideration on Infinite and Finite Dosing in Skin Permeation Using Reconstructed Models

INTRODUCTION

When vitamin derivatives penetrate the epidermis, they release active compound such as ascorbic acids (AsA) and tocopherols via enzymatic digestion of chemical modifiers. To determine the transdermal penetration of the derivatives, the total permeation of both the derivatives and their active compounds that released from the derivatives should be considered. In this study, we established a skin penetration test method using a cultured, reconstructed skin model with active epidermal enzymes. And we analyzed two vitamin derivatives with different chemical properties: magnesium ascorbyl phosphate (APM) and sodium tocopheryl phosphate (TPNa), both of which has been confirmed their skin permeation in the reconstructed models and the digestion to AsA and α-tocopherol by the epidermal enzymes, respectively.

METHODS

We prepared the 1% of water solution containing either APM or TPNa. Then, we tested the cumulative permeation of the derivatives at 2 application volumes, 25 μL/cm2 (finite dosing) and 85 μL/cm2 (infinite dosing), on cultured reconstructed skin and observed the permeation of the permeants every 2 h up to 24 h.

RESULTS

When the applied formula was used to assess the evaporation rate to determine an end point of the test system, all the water evaporated in 6 h in finite model and in 8 h in infinite model. Both models showed that the cumulative permeation of the active compounds increased and a constant flux until 8 h after application; however, the flux decreased thereafter, indicating that the decreased flux depended on an end point of the test system. This indicated that our test system can analyze the permeation of the vitamin derivatives within 8 h before reaching the end point.

CONCLUSION

Using an infinite model of this system, we assessed the cumulative permeation of vitamin derivatives within 8 h using a reconstructed skin model.

INTRODUCTION

When vitamin derivatives penetrate the epidermis, they release active compound such as ascorbic acids (AsA) and tocopherols via enzymatic digestion of chemical modifiers. To determine the transdermal penetration of the derivatives, the total permeation of both the derivatives and their active compounds that released from the derivatives should be considered. In this study, we established a skin penetration test method using a cultured, reconstructed skin model with active epidermal enzymes. And we analyzed two vitamin derivatives with different chemical properties: magnesium ascorbyl phosphate (APM) and sodium tocopheryl phosphate (TPNa), both of which has been confirmed their skin permeation in the reconstructed models and the digestion to AsA and α-tocopherol by the epidermal enzymes, respectively.

METHODS

We prepared the 1% of water solution containing either APM or TPNa. Then, we tested the cumulative permeation of the derivatives at 2 application volumes, 25 μL/cm2 (finite dosing) and 85 μL/cm2 (infinite dosing), on cultured reconstructed skin and observed the permeation of the permeants every 2 h up to 24 h.

RESULTS

When the applied formula was used to assess the evaporation rate to determine an end point of the test system, all the water evaporated in 6 h in finite model and in 8 h in infinite model. Both models showed that the cumulative permeation of the active compounds increased and a constant flux until 8 h after application; however, the flux decreased thereafter, indicating that the decreased flux depended on an end point of the test system. This indicated that our test system can analyze the permeation of the vitamin derivatives within 8 h before reaching the end point.

CONCLUSION

Using an infinite model of this system, we assessed the cumulative permeation of vitamin derivatives within 8 h using a reconstructed skin model.

Psoriatic skin transcript phenotype: androgen/estrogen and cortisone/cortisol imbalance with increasing DNA damage response

BACKGROUND

Patients prone to psoriasis suffer after a breakdown of the epidermal barrier and develop poorly healing lesions with abnormal proliferation of keratinocytes. Strong inflammatory reactions with genotoxicity (short telomeres) suggest impaired immune defenses with DNA damage repair response (DDR) in patients with psoriasis. Recent evidence indicates the existence of crosstalk mechanisms linking the DDR machinery and hormonal signaling pathways that cooperate to influence both progressions of many diseases and responses to treatment. The aim of this study was to clarify whether steroid biosynthesis and genomic stability markers are altered in parallel during the formation of psoriatic skin. Understanding the interaction of the steroid pathway and DNA damage response is crucial to addressing underlying fundamental issues and managing resulting epidermal barrier disruption in psoriasis.

METHODS

Skin (Lesional, non-lesional) and blood samples from twenty psoriasis patients and fifteen healthy volunteers were collected. Real-Time-PCR study was performed to assess levels of known transcripts such as: estrogen (ESR1, ESR2), androgen (AR), glucocorticoid/mineralocorticoid receptors (NR3C1, NR3C2), HSD11B1/HSD11B2, and DNA damage sensors (SMC1A, TREX1, TREX2, SSBP3, RAD1, RAD18, EXO1, POLH, HUS1).

RESULTS

We found that ESR1, ESR2, HSD11B1, NR3C1, NR3C2, POLH, and SMC1A transcripts were significantly decreased and AR, TREX1, RAD1, and SSBP3 transcripts were increased dramatically in the lesional skin compared to skin samples of controls.

CONCLUSION

We found that the regulation of the steroidogenic pathway was disrupted in the lesional tissue of psoriasis patients and that a sufficient glucocorticoid and mineralocorticoid response did not form and the estrogen/androgen balance was altered in favour of androgens. We suggest that an increased androgen response in the presence of DDR increases the risk of developing psoriasis. Although this situation may be the cause or the consequence of a disruption of the epidermal barrier, our data suggest developing new therapeutic strategies.

Transcriptomics analysis reveals molecular alterations underpinning spaceflight dermatology

BACKGROUND

Spaceflight poses a unique set of challenges to humans and the hostile spaceflight environment can induce a wide range of increased health risks, including dermatological issues. The biology driving the frequency of skin issues in astronauts is currently not well understood.

METHODS

To address this issue, we used a systems biology approach utilizing NASA's Open Science Data Repository (OSDR) on space flown murine transcriptomic datasets focused on the skin, biochemical profiles of 50 NASA astronauts and human transcriptomic datasets generated from blood and hair samples of JAXA astronauts, as well as blood samples obtained from the NASA Twins Study, and skin and blood samples from the first civilian commercial mission, Inspiration4.

RESULTS

Key biological changes related to skin health, DNA damage & repair, and mitochondrial dysregulation are identified as potential drivers for skin health risks during spaceflight. Additionally, a machine learning model is utilized to determine gene pairings associated with spaceflight response in the skin. While we identified spaceflight-induced dysregulation, such as alterations in genes associated with skin barrier function and collagen formation, our results also highlight the remarkable ability for organisms to re-adapt back to Earth via post-flight re-tuning of gene expression.

CONCLUSION

Our findings can guide future research on developing countermeasures for mitigating spaceflight-associated skin damage.

Ionic composition of Shotokuseki extract alters cell differentiation and lipid metabolism in three-dimensional cultured human epidermis

Corneocytes and intercellular lipids form the stratum corneum. The content and composition of intercellular lipids in the stratum corneum significantly affect skin barrier function. The purpose of this study was to demonstrate the effect of Shotokuseki extract (SE) on intercellular lipid production and metabolism in human three-dimensional cultured human epidermis. SE or ion mixtures containing five common ions were applied to three-dimensional cultured human epidermis for 2-8 days for each assay. The mRNA expression levels of epidermal differentiation markers and lipid metabolism genes were quantified by real-time PCR. After extraction of lipids from the epidermis, ceramide, sphingosine, free fatty acids, and cholesterol were quantified by LC-MS/MS, GC-MS, or HPLC. The results showed that the application of SE increased the gene expression levels of epidermal differentiation markers keratin10 and transglutaminase. Elongation of very long-chain fatty acids protein 3, serine palmitoyl transferase, ceramide synthase 3, and acid ceramidase mRNA expression levels increased and fatty acid synthase mRNA expression decreased. The content of each lipid, [EOS] ceramide decreased and total sphingosine content increased on day 4. On day 8 of application, ceramide [NDS], [NP], and [EODS] increased and total free fatty acid content decreased. These results show that SE alters the lipid composition of the epidermis, increasing ceramides and decreasing free fatty acids in the epidermis. The composition of the ions in the SE may be responsible for the changes in lipid composition. These behaviors were different from those observed when the ion mixture was applied.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-024-00616-3.

Current insights into skin lipids and their roles in cutaneous health and disease

PURPOSE OF REVIEW

The unique and complex array of cutaneous lipids include essential components of the skin structure and signalling molecules mediating homeostasis and inflammation. Understanding skin lipid biology and metabolism can support our comprehension of health and disease, including systemic conditions with cutaneous involvement.

RECENT FINDINGS

Lipids found on the skin surface, produced by both the host and resident microbes, maintain and regulate the skin microbiome and the epidermal barrier, whilst altered contributions from either source can be detrimental to skin health. The unique lipid composition of the epidermal barrier is essential for its function, and recent studies have expanded our understanding of epidermal ceramide production. This has been supported by improved models available for skin research, including organotypic skin models enabling in-vitro production of complex acylceramides for the first time, and model systems facilitating in-silico exploration of the lipid profile changes observed in clinical samples. Studies have revealed further involvement of lipid mediators such as eicosanoids in cutaneous inflammation, as well as immune regulation in both healthy and diseased skin.

SUMMARY

Skin lipids offer exciting opportunities as therapeutic targets for many conditions, whether through topical interventions or nutritional supplementation.

Menopause induces changes to the stratum corneum ceramide profile, which are prevented by hormone replacement therapy

The menopause can lead to epidermal changes that are alleviated by hormone replacement therapy (HRT). We hypothesise that these changes could relate to altered ceramide production, and that oestrogen may have a role in keratinocyte ceramide metabolism. White Caucasian women were recruited into three groups: pre-menopausal (n = 7), post-menopausal (n = 11) and post-menopausal taking HRT (n = 10). Blood samples were assessed for hormone levels, transepidermal water loss was measured to assess skin barrier function, and stratum corneum lipids were sampled from photoprotected buttock skin. Ceramides and sphingomyelins were analysed by ultraperformance liquid chromatography with electrospray ionisation and tandem mass spectrometry. Post-menopausal stratum corneum contained lower levels of ceramides, with shorter average length; changes that were not evident in the HRT group. Serum oestradiol correlated with ceramide abundance and length. Ceramides had shorter sphingoid bases, indicating altered de novo ceramide biosynthesis. Additionally, post-menopausal women had higher sphingomyelin levels, suggesting a possible effect on the hydrolysis pathway. Treatment of primary human keratinocytes with oestradiol (10 nM) increased production of CER[NS] and CER[NDS] ceramides, confirming an effect of oestrogen on cutaneous ceramide metabolism. Taken together, these data show perturbed stratum corneum lipids post-menopause, and a role for oestrogen in ceramide production.