Expression Of Involucrin Research Articles

Terminal differentiation of keratinocytes was damaged in type 2 diabetic mice.

Although skin manifestations are common in diabetic patients, its characteristics are poorly identified. This study explored the differentiation process of keratinocytes in type 2 diabetes mellitus (T2DM) in vivo. Back skin of T2DM model KKAy/TaJcl mice (KKAy) and C57BL/6JJcl mice (control) aged 8 and 12weeks was used. The mRNA expression of differentiation markers of keratinocytes was measured by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of each marker in situ was examined immunohistochemically. KKAy mice showed hyperglycemia versus control mice. The histological findings showed increased thickness and structural impairment of epidermal tissue in KKAy mice. The qRT-PCR revealed that the expression of integrin beta 1 and keratin 14 in KKAy and control mice was identical. However, the expression of involucrin at 8 weeks, keratin 10 at 12 weeks, and filaggrin and loricrin at 8 and 12 weeks was decreased in KKAy mice. Immunohistochemical findings showed that filaggrin was markedly decreased in KKAy mice, though Ki-67 remained unchanged. The terminal differentiation process was impaired in the diabetic skin, while keratinocyte proliferation was preserved. Damaged terminal differentiation of keratinocytes may contribute to impairment of the skin barrier function in diabetic dermatoses.

614 Laser-treatment of Hypertrophic Scar Induces Change to Epidermal Histoarchitecture Correlating to Improved Epidermal Barrier Function

IntroductionMechanisms and timing of hypertrophic scar (HTS) improvement with laser therapy are incompletely understood. Epidermal keratinocytes influence HTS through paracrine signaling, yet they are understudied compared to fibroblasts. It was hypothesized that fractional ablative CO2 laser scar revision (FLSR) would change the fibrotic histoarchitecture of the epidermis in HTS.MethodsDuroc pigs (n=4 FLSR and n=4 controls) were injured and allowed to form HTS. HTS and normal skin (NS) were assessed weekly by non-invasive skin probes measuring trans-epidermal water loss (TEWL) and biopsy collection. There were 4 weekly FLSR treatments. Early laser treatment began on day 49, and late began on day 77. Punch biopsies from NS and HTS were processed and stained with H&E. Image J was used to obtain epidermal thickness and rete ridge ratios (RRR). Gene and protein expression of involucrin (IVL) was examined through qRT-PCR and immunofluorescent (IF) staining.ResultsAfter treatment, peeling sheets of stratum corneum were apparent which were not present in the controls. TEWL was increased in HTS vs. NS at day 49 indicating decreased barrier function (42.2±8.0 vs. 22.0±4.62g/m2h, p=0.05). In the early group, TEWL was significantly decreased at week 4 to 16.4±3.5 g/m2h (p< 0.05). The late group was not significantly altered from NS at the pre-laser timepoint (day 77=12.1±1.99 g/m2h). Hence, there was no decrease in TEWL post-FLSR. After 4 sessions, epidermal thickness was significantly increased in treated scars in both FLSR groups (early:pre=85.6±6.8 vs. week 4=115.2±12.0 µm, p< 0.01) and (late:pre=75.2±6.6 vs. week 4=125.7±12.0 µm p< 0.001, n=8 scars,). There was no increase in controls. Late intervention significantly increased RRR (pre=1.3±0.1 vs. week 4=1.9±0.1, n=8 scars, p< 0.05), and early treatment trended towards increase (pre=1.17±0.05 vs. week 4=1.4 + 0.1). There was no increase in controls. There was increased IVL gene expression in HTS vs. NS that decreased after FLSR. Eight scars had up-regulated gene expression of IVL vs. NS levels pre-treatment (FC >1.5) compared to 4 scars at week 4. This was confirmed by IF where IVL staining decreased at week 4.ConclusionsChanges in epidermal HTS histoarchitecture and expression levels of epidermal differentiation markers were induced by FLSR. The timing of laser intervention contributed to differences in TEWL, epidermal thickness, and RRR.

Preclinical Testing of Dendritic Core-Multishell Nanoparticles in Inflammatory Skin Equivalents.

Human skin equivalents emerged as novel tools in preclinical dermatological research. It is being claimed that they may bridge the translational gap between preclinical and clinical research, yet only a few studies have investigated their suitability for preclinical drug testing so far. Therefore, we investigated if inflammatory skin equivalents, which emulate hallmarks of atopic dermatitis (AD), are suitable to assess the anti-inflammatory effects of dexamethasone (DXM) in a cream formulation or loaded onto dendritic core-multishell nanoparticles. Topical DXM application resulted in significantly decreased expression of the proinflammatory cytokine TSLP, increased expression of the skin barrier protein involucrin, and facilitated glucocorticoid receptor translocation in a dose-dependent manner. Further, DXM treatment inhibited gene expression of extracellular matrix components, potentially indicative of the known skin atrophy-inducing side effects of glucocorticoids. Overall, we were able to successfully assess the anti-inflammatory effects of DXM and the superiority of the nanoparticle formulation. Nevertheless the identification of robust readout parameters proved challenging and requires careful study design.

Differences of water barrier function between keloid and its surrounding normal skin in patients with keloids and its related mechanism

Objective: To compare the differences of water barrier function between keloids and its surrounding normal skin in patients with keloids, and to explore the primary mechanism. Methods: A cross-sectional observational study was conducted. From October 2020 to March 2021, 30 patients with keloids who met the inclusion criteria visited Shanghai Ninth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, including 18 females and 12 males, aged 20-48 years. The transepidermal water loss (TEWL) of their keloids and the surrounding normal skin of the 30 patients were measured by multi probe adapter on the reception day. The keloid tissues and normal skin of 5 patients after keloid repair surgery were processed for hematoxylin-eosin staining to measure the thickness of epidermis. Immunohistochemistry was performed on samples from 3 of those 5 patients to detect the expressions of cytokeratin-10, involucrin, and filaggrin in keloids and normal skin. Data were statistically analyzed with paired sample t test and independent sample t test. Results: On the reception day, the TEWL of keloids of 30 patients was 9.0 (6.9, 13.4) g·m-2·h-1 and the TEWL of the normal skin was 8.1 (6.4, 18.1) g·m-2·h-1, between which the difference was not statistically significant (t=0.44, P>0.05). After keloid repair surgery, the thickness of epidermis in the keloids of 5 patients was (194±44) μm, which was significantly thicker than that of the normal skin (44±11) μm, (t=6.88, P<0.01). Furthermore, increased keratinocytes, lack of normal epidermal ridge structures, and thickened stratum corneum were observed in the keloid area. After keloid repair surgery, the expression level of cytokeratin-10 in keloids was significantly lower than that in normal skin of 3 patients (t=8.50, P<0.01), but there were no statistically significant differences in the expression levels of involucrin or filaggrin between keloids and normal skin (with t values of 0.07 and 0.96, respectively, P>0.05). Conclusions: Keloid tissue from patients with keloids displays increased number of keratinocytes and thickened epidermis. But the water barrier function in keloid area is similar to the surrounding normal skin, suggesting that TEWL may not be the main mechanism lead to the persistent development of keloids.

Keratinocyte differentiation and proteolytic pathways in skin (patho) physiology.

The epidermis is a stratified epithelium that forms the barrier between the organism and its environment. It is mainly composed of keratinocytes at various stages of differentiation. The stratum corneum is the outermost layer of the epidermis and is formed of multiple layers of anucleated keratinocytes called corneocytes. We aim to highlight the roles of epidermal differentiation and proteolysis in skin diseases. Skin biopsies isolated from Spink5-/- mice, the established model of Netherton syndrome (NS), and from patients with NS, seborrheic dermatitis (SD) and psoriasis, as well as healthy controls, were analyzed by histology and immunohistochemistry. Our results showed that NS, SD, and psoriasis are all characterized by abnormal epidermal differentiation, manifested by hyperplasia, hyperkeratosis, and parakeratosis. At the molecular level, abnormal differentiation is accompanied by increased expression of involucrin and decreased expression of loricrin in NS and psoriasis. Increased epidermal proteolysis associated with increased kallikrein-related peptidases (KLKs) expression is also observed in both NS and psoriatic epidermis. Furthermore, reduced expression of desmosomal proteins is observed in NS, but increased in psoriasis. Since desmosomal proteins are proteolytic substrates and control keratinocyte differentiation, their altered expression directly links epidermal proteolysis to differentiation. In conclusion, abnormal cellular differentiation and proteolysis are interconnected and underlie the pathology of NS, SD and psoriasis.

Preclinical evidence for pioglitazone and bexarotene combination in oral cancer chemoprevention.

Head and neck squamous cell carcinoma (HNSCC) requires new treatments and targeted approaches to improve survival. The peroxisome proliferator-activated receptor γ (PPARγ) and retinoic X receptor alpha (RXRα) nuclear receptor pathways may be targetable with repurposed Food and Drug Administration (FDA)-approved agents for prevention and treatment. Oral cancer and leukoplakia cell lines were treated with the PPARγ agonist (pioglitazone) and RXRα activator (bexarotene). PPARγ activation, cellular proliferation, apoptosis activity and phenotype, including the pharmacodynamic marker, involucrin (IVL), were subsequently analyzed using a reporter gene assay, genomic data, MTT assay and western blot. Microarray analysis of HNSCC tumor versus normal tissue shows IVL expression is significantly increased in normal tissue compared to HNSCC tumors (p < 0.0001). In MSK Leuk1 and CA 9-22 cell lines, pioglitazone increases PPARγ DNA binding activity and IVL promoter activity in a dose dependent manner (p < 0.01 and p < 0.0001). Combination treatment with pioglitazone and bexarotene increases PPARγ DNA binding activity and IVL promoter activity (p < 0.01 and p < 0.0001). MTT analysis shows decreases in cell proliferation when cells are treated with pioglitazone and bexarotene. Decreases in cell proliferation are significant to at least p < 0.05 for all combination versus single agent treatments. Western blot on whole-cell lysate from cells treated with pioglitazone and bexarotene alone or in combination for IVL showed increased protein levels with combination treatment. Targeting the PPARγ/RXRα heterodimer with pioglitazone and bexarotene was effective in this preclinical project. This was functional in both preneoplastic and oral cancer cell lines. A better understanding of the molecular mechanism on downstream effects on cellular proliferation could potentially have implications clinically, both in oral preneoplasia and possibly head and neck cancer; however, more research needs to be done to explore the potential these medications have in chemoprevention.

MAB21L4 regulates the TGF-β-induced expression of target genes in epidermal keratinocytes.

Smad proteins transduce signals downstream of transforming growth factor-β (TGF-β) and are one of the factors that regulate the expression of genes related to diseases affecting the skin. In the present study, we identified MAB21L4, also known as male abnormal 21 like 4 or C2orf54, as the most up-regulated targets of TGF-β and Smad3 in differentiated human progenitor epidermal keratinocytes using chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq). We found that TGF-β induced expression of the barrier protein involucrin (encoded by the IVL gene). Transcriptional activity of the IVL promoter induced by TGF-β was inhibited by MAB21L4 siRNAs. Further analysis revealed that MAB21L4 siRNAs also down-regulated the expression of several target genes of TGF-β. MAB21L4 protein was located mainly in the cytosol, where it was physically bound to Smad3 and a transcriptional corepressor c-Ski. siRNAs for MAB21L4 did not inhibit the binding of Smad3 to their target genomic regions but down-regulated the acetylation of histone H3 lys 27 (H3K27ac), an active histone mark, near the Smad3 binding regions. These findings suggest that TGF-β-induced MAB21L4 up-regulates the gene expression induced by TGF-β, possibly through the inhibition of c-Ski via physical interaction in the cytosol.

Eisenia bicyclis Extract Repairs UVB-Induced Skin Photoaging In Vitro and In Vivo: Photoprotective Effects.

Chronic exposure to ultraviolet B (UVB) is a major cause of skin aging. The aim of the present study was to determine the photoprotective effect of a 30% ethanol extract of Eisenia bicyclis (Kjellman) Setchell (EEB) against UVB-induced skin aging. By treating human dermal fibroblasts (Hs68) with EEB after UVB irradiation, we found that EEB had a cytoprotective effect. EEB treatment significantly decreased UVB-induced matrix metalloproteinase-1 (MMP-1) production by suppressing the activation of mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) signaling and enhancing the protein expression of tissue inhibitors of metalloproteinases (TIMPs). EEB was also found to recover the UVB-induced degradation of pro-collagen by upregulating Smad signaling. Moreover, EEB increased the mRNA expression of filaggrin, involucrin, and loricrin in UVB-irradiated human epidermal keratinocytes (HaCaT). EEB decreased UVB-induced reactive oxygen species (ROS) generation by upregulating glutathione peroxidase 1 (GPx1) and heme oxygenase-1 (HO-1) expression via nuclear factor erythroid-2-related factor 2 (Nrf2) activation in Hs68 cells. In a UVB-induced HR-1 hairless mouse model, the oral administration of EEB mitigated photoaging lesions including wrinkle formation, skin thickness, and skin dryness by downregulating MMP-1 production and upregulating the expression of pro-collagen type I alpha 1 chain (pro-COL1A1). Collectively, our findings revealed that EEB prevents UVB-induced skin damage by regulating MMP-1 and pro-collagen type I production through MAPK/AP-1 and Smad pathways.

The remarkable effect of menstrual blood stem cells seeded on bilayer scaffold composed of amniotic membrane and silk fibroin aiming to promote wound healing in diabetic mice

IntroductionImpaired chronic wound healing frequently occurs in diabetic patients. We hypothesized that menstrual blood-derived mesenchymal stem cells (MenSCs) in combination with bilayer scaffold consisted of human amniotic membrane (AM) and electrospun silk fibroin nanofibers could potentially promote wound healing in diabetic mice. Methods & MethodsTwo bilateral full-thickness wounds were created on dorsal skin of type-1 diabetic mice model and animals were equally divided in four groups including: no-treatment group (NT), amniotic membrane treated group (AM), bilayer scaffold treated group (bSC), and MenSCs-seeded bilayer scaffold treated group (bSC + MenSCs). Wound healing evaluations were performed at 3, 7, and 14 days after their treatment. The wound healing was analyzed by macroscopic and microscopic evaluations, and immunofluorescence staining of involucrin (IVL), type III collagen, CD31/ von Willebrand factor (vWF), and PGP9.5 were performed. Furthermore, number of neutrophils and macrophages and subpopulation of macrophages were assessed. In addition, the expression of Egr2, Mmp9, CXCL12, IDO1, Ptgs2 and VEGFA transcripts involved in wound repair were also analyzed. ResultsAfter 14 days, the best epidermal and dermal regeneration belonged to the cases received bSC + MenSCs as wound dressing. Moreover, the wound healing was typically faster in this group compared to other groups. Immunofluorescence evaluation represented higher levels of CD31 and VWF, higher ratio of M2/M1 macrophages, greater expression of IVL, and higher levels of the PGP9.5 in the bSC + MenSCs group in comparison with other groups. Expression analysis of assessed genes also supported assumption of more regeneration and healing in the bSC + MenSCs group versus other groups. ConclusionThese results indicate that enhanced immunomodulatory and reparative properties of MenSCs in conjunction with bilayer scaffold specified this cellular skin substitute for modulating wound chronicity and contribution to resolution of wound healing process in diabetic ulcer.

Comparison of Epidermal Barrier Integrity in Adults with Classic Atopic Dermatitis, Atopic Prurigo and Non-Atopic Prurigo Nodularis.

Simple SummaryAtopic dermatitis, also called neurodermatitis, is one of the best-known chronic inflammatory skin diseases with eczema, strong itch and dry skin. It is based on an impaired skin barrier with changes in the fats and proteins of the horny layer, which leads to a disturbed water balance. Prurigo nodularis is a less common and intractable chronic skin disease with very itchy nodules. It can be associated with atopic dermatitis (so called atopic prurigo) or with many other diseases. The aim of this study was to compare these three skin diseases classic atopic dermatitis, atopic prurigo and non-atopic prurigo nodularis with healthy control subjects with regard to their skin barrier. In all three disease groups, we then found marked disease severity, reduced water content and increased water loss through the skin, thickening and inflammation of the skin, altered levels of certain proteins and reduced fat layers, all of which demonstrate a severe disturbance of the skin barrier. The main therapeutic consequence is that basic barrier repair, as established for patients with atopic dermatitis in the form of consistent skincare, could also be crucial for patients with non-atopic prurigo nodularis due to this verified skin barrier damage.A deficient epidermal barrier is a key feature of atopic dermatitis (AD) and comprises altered lipid and protein content and composition of the stratum corneum resulting in disturbed water balance. Clinically, eczematous lesions on dry skin and pruritus develop. Pruritic nodules occur in prurigo nodularis (PN), another chronic skin disease, which can be associated with atopy. We aimed at comparing the three clinical pictures, classic AD, atopic prurigo (AP), and non-atopic PN, to healthy controls regarding the epidermal barrier. We determined clinical parameters and performed biophysical measurements, histology/immunohistochemistry, electron microscopy, and molecular biological analysis. We found distinctively elevated clinical scores, reduced hydration and increased transepidermal water loss, epidermal hyperplasia and inflammation reduced filaggrin and increased loricrin and involucrin expression, as well as reduced intercellular lipid lamellae in all three disease groups. These findings show a severe disruption in epidermal barrier structure and function in all three disorders so that epidermal barrier impairment is now proven not only for AD but also for PN.

142 Epidermal equivalents on nonwoven collagen scaffolds

The use of natural polymers such as collagen for tissue engineering has many advantages providing cells with an environment of natural topography and rich of bioactive cues. Nevertheless, as compared to synthetic polymers, electrospinning of such materials is still a methodological challenge. Two nonwoven scaffolds were fabricated by collagen dispersion in hexafluoroisopropanol (HFIP) (microfibrous) and in acetic acid (nanofibrous) and stabilized by genipin. The helical structure of collagen was retained in acetic acid, but not in HFIP. Epidermal equivalents were prepared using human primary keratinocytes on both types of materials. There were up to seven layers of live cells with well-defined granular layer in the stratified epithelium obtained on nanofibrous scaffolds. The stratum corneum (SC) was well pronounced and desquamation was evident. The patterns of involucrin expression were similar, but not identical to the normal epidermis: it demarcated all suprabasal layers, not the uppermost ones as it was shown for filaggrin. The basement membrane (BM) component laminin 5 was deposited on the surface of the fibers, but a compact BM structure was not formed. CK5 expression was not limited to the basal layer, but observed in all living layers of the equivalent. The stratified epithelium formed on the microfiber materials also had a well-distinguishable granular layer and SC. But SC was thinner as compared to nanofiber samples. The expression pattern of involucrin was much closer to normal than on nanofiber scaffold while filaggrin and CK5 showed localization similar to nanofiber scaffolds. The laminin 5 positivity was insignificant. Thus, we have managed to obtain nonwoven collagen matrices of two different types (nanofibrous and microfibrous) which both support the formation of stratified epithelium. Of note, the use of nanofibrous material yields epidermal equivalents with more prominent basal layer and synthesis of BM components, while equivalents on microfibrous material gave more “normal” patterns of involucrin and filaggrin expression.

Mechanism of improving skin barrier function in a mouse model of atopic dermatitis using Mahuang Lianqiao Chixiaodou decoction and its disassembled formula

To reveal the mechanism of Mahuang Lianqiao Chixiaodou decoction and its disassembled formula for improving the skin barrier function in a mouse model of atopic dermatitis (AD). Sixty specific-pathogen free male BALB/c mice were randomly divided into the control group, model group, whole formula group (WF), exterior-releasing formula group (ERF), interior-clearing formula group (ICF), and positive control group (PC). A mouse model of AD was established using the semi-antigen 2,4-dinitrofluorobenzene induction method. The lesion scores, transepidermal water loss and pH, and skin histopathology of mice in each group were observed. The expressions of filaggrin, loricrin, and involucrin were detected by the streptavidin peroxidase immunohistochemical method and western blotting, and their mRNA expressions were detected by quantitative polymerase chain reaction. Mice in the WF, ERF, ICF, and PC groups showed reduced skin lesion performance, improved histopathology, decreased skin lesion score, transepidermal water loss and pH, and upregulated expressions of proteins including filaggrin, loricrin, and involucrin, and their mRNAs. The most obvious regulatory effect was observed in the WF group, followed by the ICF, ERF, and PC groups, accordingly. Mahuang Lianqiao Chixiaodou decoction and its disassembled formula can improve the skin barrier function in a mouse model of AD by upregulating filaggrin, loricrin, and involucrin, and their mRNA expressions, and the most optimal effect was noted in the WF group, followed by the ICF and ERF groups, which suggests that the effect of clearing heat and resolving dampness in improving the skin barrier function of AD is more obvious and is one of the key treatments for AD.

102 Loss of volume-regulated anion channel LRRC8 interferes with cell volume regulation and epidermal homeostasis

The volume-regulated anion channel LRRC8 contributes to cell volume regulation upon hypoosmotic stress in keratinocytes. In a hypotonic environment water enters the cell and leads to an increase in cell volume, which is counteracted by a chloride efflux mediated by LRRC8. We found that the essential LRRC8 subunit namely LRRC8A is mainly expressed in the basal epidermal layers with highest expression in transient amplifying cells. Thus, we hypothesize that it potentially plays an important role during the switch between proliferation and differentiation in these cells. To analyze the function of LRRC8A in human keratinocytes, we established a siRNA-mediated knockdown in primary keratinocytes. These cells displayed aberrant expression of involucrin and keratin 10 in differentiating cells, while filaggrin and keratin 14 were unchanged. To overcome experimental variations and get a better understanding of the underlying processes, we generated an LRRC8A- knockout cell line from immortalized keratinocytes using CRISPR/Cas9. The knockout was validated on DNA and protein levels and further verified by manual patch clamping, which showed complete disappearance of VRAC-mediated ionic currents. LRRC8A-/- cells showed a reduced proliferation rate and disturbed epidermal maturation in 2D differentiation assays. Interestingly, LRRC8A-/- cells were unable to reconstitute a 3D epidermis in vitro, indicating that LRRC8 is potentially involved in differentiation initiation. Taken together, our findings suggest that LRRC8 ion channels control cell volume changes in the epidermis, which could represent an essential mechanism, when keratinocytes leave the proliferative, basal compartment and initiate differentiation. Further work will indicate via which molecular processes LRRC8 regulates epidermal renewal and contributes to skin homeostasis.

Development of a 3D psoriatic skin model optimized for infiltration of IL-17A producing T cells: Focus on the crosstalk between T cells and psoriatic keratinocytes

Psoriasis is a chronic inflammatory skin disease involving several cell types, including T cells, via the IL-23/IL-17 axis. IL-17A acts on the surrounding epithelial cells thus resulting in an inflammatory feedback loop. The development of immunocompetent models that correctly recapitulate the complex phenotype of psoriasis remains challenging, which also includes both the T cell isolation and activation methods. The purpose of this work was to develop an advanced in vitro 3D psoriatic skin model that enables the study of the impact of T cells on psoriatic epithelial cells. To reach that aim, healthy and psoriatic fibroblasts and keratinocytes were used to reproduce this tissue-engineered skin model in which activated T cells, isolated beforehand from human whole blood, have been incorporated. Our study showed that isolation of T cells with the EasySep procedure, followed by activation with PMA/ionomycin, mimicked the psoriatic characteristics in an optimal manner with the production of inflammatory cytokines important in the pathogenesis of psoriasis, as well as increased expression of Ki67, S100A7, elafin and involucrin. This psoriatic model enriched in activated T cells displayed enhanced production of IL-17A, IFN-ƴ, CCL2, CXCL10, IL-1ra, IL-6 and CXCL8 compared with the healthy model and whose increased secretion was maintained over time. In addition, anti-IL17A treatment restored some psoriatic features, including epidermal thickness and basal keratinocytes proliferation, as well as a downregulation of S100A7, elafin and involucrin expression. Altogether, our study demonstrated that this model reflects a proper psoriatic inflammatory environment and is effective for the investigation of epidermal and T cell interaction over time. Statement of significanceThe aim of this study was to provide an innovative 3D immunocompetent human psoriatic skin model. To our knowledge, this is the first immunocompetent model that uses skin cells from psoriatic patients to study the impact of IL-17A on pathological cells. Through the use of this model, we demonstrated that the T-cell enriched psoriatic model differs from T-cell enriched healthy model, highlighting efficient crosstalk between pathologic epithelial cells and T cells. This advanced preclinical model further mimics the original psoriatic skin and will prove relevant in predicting clinical outcomes, thereby decreasing inaccurate predictions of compound effects.

Lithospermum erythrorhizon Alleviates Atopic Dermatitis-like Skin Lesions by Restoring Immune Balance and Skin Barrier Function in 2.4-Dinitrochlorobenzene-Induced NC/Nga Mice.

The incidence of atopic dermatitis (AD), a disease characterized by an abnormal immune balance and skin barrier function, has increased rapidly in developed countries. This study investigated the anti-atopic effect of Lithospermum erythrorhizon (LE) using NC/Nga mice induced by 2,4-dinitrochlorobenzene. LE reduced AD clinical symptoms, including inflammatory cell infiltration, epidermal thickness, ear thickness, and scratching behavior, in the mice. Additionally, LE reduced serum IgE and histamine levels, and restored the T helper (Th) 1/Th2 immune balance through regulation of the IgG1/IgG2a ratio. LE also reduced the levels of AD-related cytokines and chemokines, including interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor-α (TNF-α), thymic stromal lymphopoietin, thymus and activation-regulated chemokine, macrophage-derived chemokine, regulated on activation, normal T cell expressed and secreted, and monocyte chemoattractant protein-1 in the serum. Moreover, LE modulated AD-related cytokines and chemokines expressed and secreted by Th1, Th2, Th17, and Th22 cells in the dorsal skin and splenocytes. Furthermore, LE restored skin barrier function by increasing pro-filaggrin gene expression and levels of skin barrier-related proteins filaggrin, involucrin, loricrin, occludin, and zonula occludens-1. These results suggest that LE is a potential therapeutic agent that can alleviate AD by modulating Th1/Th2 immune balance and restoring skin barrier function.

FAK Shutdown: Consequences on Epithelial Morphogenesis and Biomarker Expression Involving an Innovative Biomaterial for Tissue Regeneration.

By employing an innovative biohybrid membrane, the present study aimed at elucidating the mechanistic role of the focal adhesion kinase (FAK) in epithelial morphogenesis in vitro over 4, 7, and 10 days. The consequences of siRNA-mediated FAK knockdown on epithelial morphogenesis were monitored by quantifying cell layers and detecting the expression of biomarkers of epithelial differentiation and homeostasis. Histologic examination of FAK-depleted samples showed a significant increase in cell layers resembling epithelial hyperplasia. Semiquantitative fluorescence imaging (SQFI) revealed tissue homeostatic disturbances by significantly increased involucrin expression over time, persistence of yes-associated protein (YAP) and an increase of keratin (K) 1 at day 4. The dysbalanced involucrin pattern was underscored by ROCK-IISer1366 activity at day 7 and 10. SQFI data were confirmed by quantitative PCR and Western blot analysis, thereby corroborating the FAK shutdown-related expression changes. The artificial FAK shutdown was also associated with a significantly higher expression of filaggrin at day 10, sustained keratinocyte proliferation, and the dysregulated expression of K19 and vimentin. These siRNA-induced consequences indicate the mechanistic role of FAK in epithelial morphogenesis by simultaneously considering prospective biomaterial-based epithelial regenerative approaches.

Improvement of Skin Barrier Dysfunction by Phenolic‐containing Extracts of Lycium barbarum via Nrf2/HO‐1 Regulation

Lycium barbarum have received an increasing popularity due to its powerful biological activity and medicinal use. However, the effect of Lycium barbarum on skin remains largely uncharacterized. The general purpose of this paper was to characterize the phenolic compounds in Lycium barbarum extract (LBE) using LC-HRMS/QTOF method and to investigate whether topical administration of LBE can repair skin barrier dysfunction in mice. Our data demonstrated that LBE could not only decrease ROS level and matrix metalloproteinase expression, but also strengthen intrinsic antioxidant defense system including SOD, GSH-Px and CAT, thereby resulting in increased skin collagen content and an improvement of UV-induced skin erythema, thickness and wrinkles. Improved skin barrier functions were highly correlated with increased expression of filaggrin, involucrin and loricrin as well as antioxidant proteins such as Nrf2 and HO-1 in UV-irradiated mice, suggesting that LBE may be promising natural products at a lower cost for the topical application in the treatment of skin diseases with defective barrier function.

Combined loss of expression of involucrin and cytokeratin 13 is associated with poor prognosis in squamous cell carcinoma of mobile tongue.

This study aimed to evaluate the prognostic significance of expression levels of involucrin (IVL), cytokeratin (CK)-10 and -13 at different intratumor sites (tumor center and invading area) of oral tongue squamous cell carcinoma (OTSCC). IVL, CK13 and CK10 expression levels were examined in a multicenter cohort of 146 OTSCCs using immunohistochemistry. External mRNA datasets were used for expression analysis and/or to validate survival associations. External transcriptomic datasets showed downregulation of IVL and KRT13 in oral malignancies including OTSCC as compared to normal controls. The combined loss of IVL and CK13 expression at the invading core but not at the center core was significantly associated with poor differentiation and reduced 5-year overall survival. Multivariate Cox analysis confirmed the loss of CK13 and IVL expression to be an independent prognostic factor. Transcriptomic dataset corroborated immunohistochemistry results. Combined expression levlels of IVL and CK13 might be useful as prognostic biomarkers in OTSCC.

Effects of chloroform fraction of Fritillariae Thunbergii Bulbus on atopic symptoms in a DNCB-induced atopic dermatitis-like skin lesion model and in vitro models.

Ethnopharmacological relevanceFritillariae thunbergii Bulbus (FT), knowns as “Jeolpaemo (浙貝母)” in Korean traditional medicine, is a perennial plant belonging to the Liliaceae family and has been used to treat symptoms such as cough, sputum formation, and purulent pneumonia. Owing to its effects of lowering heat, removing sputum, and reducing swelling, the plant has also been used as an external prescription medicine to treat inflammation. Aim of the studyTo analyze the anti-inflammatory effects of FT-ethanol extract (FT-Et) and FT-chloroform fraction extract (FT-Cl) on 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in vivo and in vitro. Materials and methodsThe effect of FT-Et and FT-Cl on AD was observed using an AD-like skin lesion model induced by DNCB in vivo. HaCaT and RBL2H3 cells were used to determine the effects of FT-Et and FT-Cl in vitro. After inducing AD-like skin lesions in vivo, FT was topically applied to the skin lesion for 35 days. Epidermal thickness, dermal thickness, scratching behavior, infiltration of inflammatory cells, and expression of skin barrier proteins were measured. TARC, MDC, and IL-4 levels were analyzed using ELISA in HaCaT cells. Beta-hexosaminidase and IL-4 levels were measured in RBL2H3 cells. The expression of filaggrin (FLG), loricrin (LOR), involucrin (INV), and aquaporin-3(AQP-3) was measured by PCR. Phosphorylation of MAPKs was analyzed using Western blot technique. ResultsFT-Cl significantly reduced ear swelling, scratching behavior, SCORAD index, epidermal thickness, infiltration of inflammatory cells, and loss of skin barrier proteins. FT-Et inhibited the infiltration of mast cells and CD8+ cells and decreased the loss of skin barrier proteins. In TNF-α/IFN-γ-stimulated HaCaT cells, FT-Cl inhibited TRAC, MDC, and IL-4 expression and upregulated the expression of FLG, INV, and AQP-3, whereas FT-Et inhibited the expression of TRAC and MDC and increased the expression of FLG, INV, and AQP-3 at high concentrations. In RBL2H3, FT-Cl downregulated β-hexosaminidase and IL-4 expression. In addition, FT-Cl inhibited the phosphorylation of ERK and p-38 in HaCaT and RBL2H3 cells. ConclusionsCollectively, FT-Cl showed better effect than FT-Et in vivo and in vitro. These results suggest that a specific component present in FT-Cl acted against AD. Future research should focus on the analysis of components contained in FT-Cl and the anti-inflammatory effects of the active ingredient.

Selective sweep for an enhancer involucrin allele identifies skin barrier adaptation out of Africa

The genetic modules that contribute to human evolution are poorly understood. Here we investigate positive selection in the Epidermal Differentiation Complex locus for skin barrier adaptation in diverse HapMap human populations (CEU, JPT/CHB, and YRI). Using Composite of Multiple Signals and iSAFE, we identify selective sweeps for LCE1A-SMCP and involucrin (IVL) haplotypes associated with human migration out-of-Africa, reaching near fixation in European populations. CEU-IVL is associated with increased IVL expression and a known epidermis-specific enhancer. CRISPR/Cas9 deletion of the orthologous mouse enhancer in vivo reveals a functional requirement for the enhancer to regulate Ivl expression in cis. Reporter assays confirm increased regulatory and additive enhancer effects of CEU-specific polymorphisms identified at predicted IRF1 and NFIC binding sites in the IVL enhancer (rs4845327) and its promoter (rs1854779). Together, our results identify a selective sweep for a cis regulatory module for CEU-IVL, highlighting human skin barrier evolution for increased IVL expression out-of-Africa.