scholarly journals Skin permeability barrier formation by the ichthyosis-causative gene FATP4 through formation of the barrier lipid ω-O-acylceramide

2020 ◽  
Vol 117 (6) ◽  
pp. 2914-2922 ◽  
Author(s):  
Haruka Yamamoto ◽  
Miku Hattori ◽  
Walee Chamulitrat ◽  
Yusuke Ohno ◽  
Akio Kihara

The epidermis-specific lipid acylceramide plays a pivotal role in the formation of the permeability barrier in the skin; abrogation of its synthesis causes the skin disorder ichthyosis. However, the acylceramide synthetic pathway has not yet been fully elucidated: Namely, the acyl-CoA synthetase (ACS) involved in this pathway remains to be identified. Here, we hypothesized it to be encoded by FATP4/ACSVL4, the causative gene of ichthyosis prematurity syndrome (IPS). In vitro experiments revealed that FATP4 exhibits ACS activity toward an ω-hydroxy fatty acid (FA), an intermediate of the acylceramide synthetic pathway. Fatp4 knockout (KO) mice exhibited severe skin barrier dysfunction and morphological abnormalities in the epidermis. The total amount of acylceramide in Fatp4 KO mice was reduced to ∼10% of wild-type mice. Decreased levels and shortening of chain lengths were observed in the saturated, nonacylated ceramides. FA levels were not decreased in the epidermis of Fatp4 KO mice. The expression levels of the FA elongase Elovl1 were reduced in Fatp4 KO epidermis, partly accounting for the reduction and shortening of saturated, nonacylated ceramides. A decrease in acylceramide levels was also observed in human keratinocytes with FATP4 knockdown. From these results, we conclude that skin barrier dysfunction observed in IPS patients and Fatp4 KO mice is caused mainly by reduced acylceramide production. Our findings further elucidate the molecular mechanism governing acylceramide synthesis and IPS pathology.

2019 ◽  
Vol 4 ◽  
pp. 134 ◽  
Author(s):  
Martina S. Elias ◽  
Sheila C. Wright ◽  
William V. Nicholson ◽  
Kimberley D. Morrison ◽  
Alan R. Prescott ◽  
...  

Background: Atopic eczema is an itchy inflammatory disorder characterised by skin barrier dysfunction. Loss-of-function mutations in the gene encoding filaggrin (FLG) are a major risk factor, but the mechanisms by which filaggrin haploinsufficiency leads to atopic inflammation remain incompletely understood. Skin as an organ that can be modelled using primary cells in vitro provides the opportunity for selected genetic effects to be investigated in detail. Methods: Primary human keratinocytes and donor-matched primary fibroblasts from healthy individuals were used to create skin organoid models with and without siRNA-mediated knockdown of FLG. Biological replicate sets of organoids were assessed using histological, functional and biochemical measurements. Results: FLG knockdown leads to subtle changes in histology and ultrastructure including a reduction in thickness of the stratum corneum and smaller, less numerous keratohyalin granules. Immature organoids showed some limited evidence of barrier impairment with FLG knockdown, but the mature organoids showed no difference in transepidermal water loss, water content or dye penetration. There was no difference in epidermal ceramide content. Mass spectrometry proteomic analysis detected >8000 proteins per sample. Gene ontology and pathway analyses identified an increase in transcriptional and translational activity but a reduction in proteins contributing to terminal differentiation, including caspase 14, dermokine, AKT1 and TGF-beta-1. Aspects of innate and adaptive immunity were represented in both the up-regulated and down-regulated protein groups, as was the term ‘axon guidance’.      Conclusions: This work provides further evidence for keratinocyte-specific mechanisms contributing to immune and neurological, as well as structural, aspects of skin barrier dysfunction. Individuals with filaggrin deficiency may derive benefit from future therapies targeting keratinocyte-immune crosstalk and neurogenic pruritus.


Nutrients ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3638
Author(s):  
Yoon-Young Sung ◽  
Heung-Joo Yuk ◽  
Won-Kyung Yang ◽  
Seung-Hyung Kim ◽  
Dong-Seon Kim

Atopic dermatitis is a persistent inflammatory skin disorder. Siraitia grosvenorii fruits (monk fruit or nahangwa in Korean, NHG) are used as a natural sweetener and as a traditional medicine for the treatment of asthma and bronchitis. We evaluated the activity of S. grosvenorii residual extract (NHGR) on allergic inflammation of atopic dermatitis in a Dermatophagoides farinae mite antigen extract (DfE)-treated NC/Nga murine model and in vitro. Oral administration of NHGR significantly reduced epidermal hyperplasia and inflammatory cell infiltration in the skin lesions of DfE-induced atopic dermatitis, as well as the dermatitis severity score. NHGR reduced serum immunoglobulin E levels. Splenic concentrations of IFN-γ, interleukin (IL)-4, IL-5, and IL-13 were reduced by NHGR administration. Immunohistofluorescence staining showed that NHGR administration increased the protein levels of claudin-1, SIRT1, and filaggrin in atopic dermatitis skin lesions. In addition, NHGR inhibited the phosphorylation of mitogen-activated protein kinases and decreased filaggrin and chemokine protein expression in TNF-α/IFN-γ-induced human keratinocytes. Moreover, NHGR also inhibited histamine in mast cells. The quantitative analysis of NHGR revealed the presence of grosvenorine, kaempferitrin, and mogrosides. These results demonstrate that NHGR may be an efficient therapeutic agent for the treatment of atopic dermatitis.


Author(s):  
Abdul Baquee Ahmed ◽  
Gouranga Das

Objective: The aim of this investigation was to enhance the transdermal permeation of aceclofenac (ACF) from microemulsion formulation using menthol as a natural permeation enhancer. Methods: Microemulsion containing 2% w/v of ACF was prepared by a titration method with different concentration of oil, surfactant and co-surfactant. The prepared microemulsion was evaluated for droplet size, viscosity, pH and in vitro skin permeation studies. Menthol at 3-8% w/w was added to the selected microemulsion formulation and their effect on skin permeation was evaluated across rat epidermis using modified Keshary-Chien diffusion cell. The Fourier transform infrared spectroscopy (FT-IR) was performed to understand the regulation action of menthol in the skin permeability barrier. Results: The average droplet size of the microemulsion was found to be 89.4±2.12 to 175.2±3.10 nm. The transdermal flux of the microemulsion containing 8% w/w menthol showed 2.9 fold increases in transdermal flux of ACF compared with the formulation without menthol. Result of FT-IR studies showed decrease in peak height of the symmetric and asymmetric C-H stretching vibrations may be because of the extraction of the stratum corneum (SC) lipids and the alteration of the skin permeability barrier. Conclusion: This result suggests that menthol significantly enhanced the transdermal permeation of ACF and may be an effective natural penetration enhancer for transdermal delivery of the drug.


2021 ◽  
Vol 22 (23) ◽  
pp. 13091
Author(s):  
Andréa Tremblay ◽  
Mélissa Simard ◽  
Sophie Morin ◽  
Roxane Pouliot

Healthy skin moLEdels produced by tissue-engineering often present a suboptimal skin barrier function as compared with normal human skin. Moreover, skin substitutes reconstructed according to the self-assembly method were found to be deficient in polyunsaturated fatty acids (PUFAs). Therefore, in this study, we investigated the effects of a supplementation of the culture media with docosahexaenoic acid (DHA) on the barrier function of skin substitutes. To this end, 10 μM DHA-supplemented skin substitutes were produced (n = 3), analyzed, and compared with controls (substitutes without supplementation). A Franz cell diffusion system, followed by ultra-performance liquid chromatography, was used to perform a skin permeability to testosterone assay. We then used gas chromatography to quantify the PUFAs found in the epidermal phospholipid fraction of the skin substitutes, which showed successful DHA incorporation. The permeability to testosterone was decreased following DHA supplementation and the lipid profile was improved. Differences in the expression of the tight junction (TJ) proteins claudin-1, claudin-4, occludin, and TJ protein-1 were observed, principally a significant increase in claudin-1 expression, which was furthermore confirmed by Western blot analyses. In conclusion, these results confirm that the DHA supplementation of cell culture media modulates different aspects of skin barrier function in vitro and reflects the importance of n-3 PUFAs regarding the lipid metabolism in keratinocytes.


2021 ◽  
Vol 12 (4) ◽  
pp. 74-77
Author(s):  
Rabia Sannam Khan ◽  
Qudoos Yousuf

Skin has an essential role in preserving homeostasis and in maintaining the safety of the human body from outside environment by playing its role as the largest body part of human. The stratified, categorized and complex arrangement of skin gives a physical protection to the body by maintaining and regulate the transportation of metabolites and water off the body. The injuries that can originate after any chemical or physical trauma can cause impairment of skin barrier and its physiological functions.1 In skin injuries, considerable amount of skin can be lost, and it develops extremely critical to replace injury caused impaired skin. Transplants in order to protect the lots of water from body and to save the body from opportunistic pathogens can replace the impaired skin. Skin grafts can also expedite the wound recovery procedure and support and restore the barrier and can maintain the regulatory functions on the site of wound.2,3 Apart from grafts tissue engineered skin plays an exceptionally beneficial role and in vitro stage for the evaluation of skin permeability and adverse inflammation response. The tissue-engineered skin has several advantages in comparison to animal skin by having the major significance by mimicking the skin physiology and easing the ethical concerns of animal use. Additionally, tissue engineered skin models also give the significant insights into the causes of skin diseases, hence, explicate the pathophysiological mechanisms in order to see the progression, and can help in the treatment of skin disease.4,5 It has been seen that numerous tools have become accessible for the tissue engineering and are adopting different novel approaches and technologies, and amongst these 3D bioprinting offers many significant advantages Since it is possible of dispensing live cells, phase changing hydrogels, insoluble factors and maintaining high cell viability in a desired pattern.6


Development ◽  
2002 ◽  
Vol 129 (7) ◽  
pp. 1775-1784 ◽  
Author(s):  
Kursad Turksen ◽  
Tammy-Claire Troy

A defective epidermal permeability barrier (EPB) in premature birth remains a leading cause of neonatal death as a result of its associated complications, which include poor temperature stability, infection by micro-organisms through the skin, and the outflow of water. Despite its importance in survival, the mechanisms involved in the formation and maintenance of the EPB are not well understood. To address the possibility that claudins, a new superfamily of tight junctional molecules, are involved, we engineered transgenic mice with claudin 6 (Cldn6) overexpressed via the involucrin (Inv) promoter. Interestingly, the Inv-Cldn6 transgenic animals die within 2 days of birth, apparently due to the lack of an intact EPB as evidenced by increased water loss and the penetration of X-gal through the skin. Barrier dysfunction was manifested biochemically by the aberrant expression of late epidermal differentiation markers, including K1, filaggrin, loricrin, transglutaminase 3, involucrin, repetin, members of the SPRR family and the transcriptional regulator Klf4. The overall claudin profile of the epidermis was also modified. Our data suggest that repetin and SPRR1A and 2A are downregulated in response to the downregulation of Klf4 in the transgenic animals, which would contribute to decreased protein crossbridging leading to fragile, defective cornified envelopes. These results provide new insights into the role of claudin 6 in epithelial differentiation and EPB formation. In addition, the epidermal phenotype of these transgenic mice, which is very reminiscent of that in pre-term infant skin, suggest that they will be an important and novel model for studies on human premature EPB-related morbidity.


2021 ◽  
Vol 21 (5) ◽  
pp. 2901-2906
Author(s):  
Chiara Sinico ◽  
Anna Maria Fadda ◽  
Donatella Valenti ◽  
Rosa Pireddu ◽  
Francesco Corrias ◽  
...  

8-methoxypsoralen is the most common drug in psoralen plus ultraviolet light irradiation therapy for the treatment of severe psoriasis. Despite of the efficacy, its classic oral administration leads to several serious adverse effects. However, the topical psoralen application produces a drug skin accumulation lower than that obtained by oral administration, due to the drug low skin permeability. In this paper, 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles were prepared using soy phosphatidylcholine and the penetration enhancer Transcutol® (5% or 10%) and characterized in terms of size, polydispersity index, zeta potential and encapsulation efficiency. No statistically significant differences in both size (~135 nm) and encapsulation efficiency (~65%) were found for different Transcutol® concentration. Transdermal delivery study assessed by Franz diffusion cells, showed that the 8-methoxypsoralen mainly accumulated into the stratum corneum. Moreover, after Penetration Enhancer-containing Vesicles application, the drug recovered in this layer is almost double of that delivered by conventional liposomes, while no significant difference was found from the different Transcutol® concentrations. Finally, biocompatibility checked by an MTT assay, demonstrated that the incubation of human keratinocytes for 24 h with 8-methoxypsoralen loaded Penetration Enhancer-containing Vesicles did not significantly reduce cell viability.


2015 ◽  
Vol 112 (25) ◽  
pp. 7707-7712 ◽  
Author(s):  
Yusuke Ohno ◽  
Shota Nakamichi ◽  
Aya Ohkuni ◽  
Nozomi Kamiyama ◽  
Ayano Naoe ◽  
...  

A skin permeability barrier is essential for terrestrial animals, and its impairment causes several cutaneous disorders such as ichthyosis and atopic dermatitis. Although acylceramide is an important lipid for the skin permeability barrier, details of its production have yet to be determined, leaving the molecular mechanism of skin permeability barrier formation unclear. Here we identified the cytochrome P450 gene CYP4F22 (cytochrome P450, family 4, subfamily F, polypeptide 22) as the long-sought fatty acid ω-hydroxylase gene required for acylceramide production. CYP4F22 has been identified as one of the autosomal recessive congenital ichthyosis-causative genes. Ichthyosis-mutant proteins exhibited reduced enzyme activity, indicating correlation between activity and pathology. Furthermore, lipid analysis of a patient with ichthyosis showed a drastic decrease in acylceramide production. We determined that CYP4F22 was a type I membrane protein that locates in the endoplasmic reticulum (ER), suggesting that the ω-hydroxylation occurs on the cytoplasmic side of the ER. The preferred substrate of the CYP4F22 was fatty acids with a carbon chain length of 28 or more (≥C28). In conclusion, our findings demonstrate that CYP4F22 is an ultra-long-chain fatty acid ω-hydroxylase responsible for acylceramide production and provide important insights into the molecular mechanisms of skin permeability barrier formation. Furthermore, based on the results obtained here, we proposed a detailed reaction series for acylceramide production.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 6074
Author(s):  
Kyung Man Hahm ◽  
See-Hyoung Park ◽  
Sae Woong Oh ◽  
Ji Hye Kim ◽  
Hyun Sook Yeom ◽  
...  

Identifying materials contributing to skin hydration, essential for normal skin homeostasis, has recently gained increased research interest. In this study, we investigated the potential benefits and mechanisms of action of Aspergillus oryzae-fermented wheat peptone (AFWP) on the proliferation and hydration of human skin keratinocytes, through in vitro experiments using HaCaT cell lines. The findings revealed that compared to unfermented wheat peptone, AFWP exhibited an improved amino acid composition, significantly (p < 0.05) higher DPPH scavenging capability and cell proliferation activity, and reduced lipopolysaccharide-induced NO production in RAW 264.7 cells. Furthermore, we separated AFWP into eleven fractions, each ≤2 kDa; of these, fraction 4 (AFW4) demonstrated the highest efficacy in the cell proliferation assay and was found to be the key component responsible for the cell proliferation potential and antioxidant properties of AFWP. Additionally, AFW4 increased the expression of genes encoding natural moisturizing factors, including filaggrin, transglutaminase-1, and hyaluronic acid synthase 1–3. Furthermore, AFW4 activated p44/42 MAPK, but not JNK and p38 MAPK, whereas PD98059, a p44/42 MAPK inhibitor, attenuated the beneficial effects of AFW4 on the skin, suggesting that the effects of AFW4 are mediated via p44/42 MAPK activation. Finally, in clinical studies, AFW4 treatment resulted in increased skin hydration and reduced trans-epidermal water loss compared with a placebo group. Collectively, these data provide evidence that AFW4 could be used as a potential therapeutic agent to improve skin barrier damage induced by external stresses.


Author(s):  
Hyosun Jang ◽  
Hyunwook Myung ◽  
Janet Lee ◽  
Jae Kyung Myung ◽  
Won-Suk Jang ◽  
...  

Abstract: Radiation-induced skin injury can be a serious cutaneous damage and have specific characteristics. Asymptomatic periods are classified as the latent stage. The skin barrier plays a critical role in the modulation of skin permeability and hydration and protects the body against a harsh external environment. However, an analysis on the skin barrier dysfunction against radiation exposure in the latent stage has not been conducted. Thus, we investigated whether skin barrier is impaired by irradiation in the latent stage and aimed to identify the molecules involved in skin barrier dysfunction. We analyzed skin barrier function and its components in SKH-1 mice that received 20 and 40 Gy local irradiation. Increased transepidermal water loss and skin pH were observed in the latent stage of the irradiated skin. Skin barrier components, such as structural proteins and lipid synthesis enzymes in keratinocyte, increased in the irradiated group. Interestingly, we noted sebaceous gland atrophy and increased serine protease and inflammatory cytokines in the irradiated skin during the latent period. This finding indicates that the main factor of skin barrier dysfunction in the latent stage of radiation-induced skin injury is sebaceous gland deficiency, which could be an intervention target for skin barrier impairment.


Sign in / Sign up

Export Citation Format

Share Document