MiR-330 inhibits IL-22-induced keratinocyte proliferation through targeting CTNNB1

miR-26a-5p inhibits the proliferation of psoriasis-like keratinocytes in vitro and in vivo by dual interference with the CDC6/CCNE1 axis

Psoriasis is a chronic inflammatory proliferative dermatological ailment that currently lacks a definitive cure. Employing data mining techniques, this study identified a collection of substantially downregulated miRNAs (top 10). Notably, 32 targets were implicated in both the activation of the IL-17 signaling pathway and cell cycle dysregulation. In silico analysis revealed that one of these miRNAs, miR-26a-5p, is a highly conserved cross-species miRNA. Strikingly, the miR-26a-5p sequences in humans and mice are identical, and mmu-miR-26a-5p was found to target the same 7 cell cycle targets as its human counterpart, hsa-miR-26a-5p. Among these targets, CDC6 and CCNE1 were the most effective targets of miR-26a-5p, which was further validated in vitro using a dual luciferase reporter system and qPCR assay. The therapeutic assessment of miR-26a-5p revealed its remarkable efficacy in inhibiting the proliferation and G1/S transition of keratinocytes (HaCaT and HEKs) in vitro. In vivo experiments corroborated these findings, demonstrating that miR-26a-5p effectively suppressed imiquimod (IMQ)-induced psoriasis-like skin lesions in mice over an 8-day treatment period. Histological analysis via H&E staining revealed that miR-26a-5p treatment resulted in reduced keratinocyte thickness and immune cell infiltration into the spleens of IMQ-treated mice. Mechanistic investigations revealed that miR-26a-5p induced a cascade of downregulated genes associated with the IL-23/IL-17A axis, which is known to be critical in psoriasis pathogenesis, while concomitantly suppressing CDC6 and CCNE1 expression. These findings were corroborated by qPCR and Western blot analyses. Collectively, our study provides compelling evidence supporting the therapeutic potential of miR-26a-5p as a safe and reliable endogenous small nucleic acid for the treatment of psoriasis.

Small nucleolar RNA Snora73 promotes psoriasis progression by sponging miR-3074-5p and regulating PBX1 expression

Chronic psoriasis is a kind of immune-mediated skin illness and the underlying molecular mechanisms of pathogenesis remain incompletely understood. Here, we used small RNA microarray assays to scan the differential expressed RNAs in psoriasis patient samples. The downstream miRNAs and its targets were predicted using bioinformatics analysis from online bases and confirmed using fluorescence in situ hybridization and dual‑luciferase report gene assay. Cell ability of proliferation and migration were detected using CCK-8 and transwell assays. The results showed that a new snoRNA Snora73 was upregulated in psoriasis patient samples. Overexpression of Snora73 significantly increased psoriasis cells viability and migration, while knockdown of Snora73 got the opposite results. Mechanistically, our results showed that Snora73 acted as a sponge for miR-3074-5p and PBX1 is a direct target of miR-3074-5p in psoriasis cells. Furthermore, miR-3074-5p suppressed psoriasis cell proliferation and migration, while PBX1 promoted cell proliferation and migration in psoriasis. Collectively, these findings reveal a crucial role of Snora73 in progression of psoriasis through miR-3074-5p/PBX1 signaling pathway and suggest a potential therapeutic strategy.

Cux1+ proliferative basal cells promote epidermal hyperplasia in chronic dry skin disease identified by single-cell RNA transcriptomics

Pathological dry skin is a disturbing and intractable healthcare burden, characterized by epithelial hyperplasia and severe itch. Atopic dermatitis (AD) and psoriasis models with complications of dry skin have been studied using single-cell RNA sequencing (scRNA-seq). However, scRNA-seq analysis of the dry skin mouse model (acetone/ether/water (AEW)-treated model) is still lacking. Here, we used scRNA-seq and in situ hybridization to identify a novel proliferative basal cell (PBC) state that exclusively expresses transcription factor CUT-like homeobox 1 (Cux1). Further in vitro study demonstrated that Cux1 is vital for keratinocyte proliferation by regulating a series of cyclin-dependent kinases (CDKs) and cyclins. Clinically, Cux1+ PBCs were increased in patients with psoriasis, suggesting that Cux1+ PBCs play an important part in epidermal hyperplasia. This study presents a systematic knowledge of the transcriptomic changes in a chronic dry skin mouse model, as well as a potential therapeutic target against dry skin-related dermatoses.

Pathogenesis, multi-omics research, and clinical treatment of psoriasis

Psoriasis is a common inflammatory skin disease involving interactions between keratinocytes and immune cells that significantly affects the quality of life. It is characterized by hyperproliferation and abnormal differentiation of keratinocytes and excessive infiltration of immune cells in the dermis and epidermis. The immune mechanism underlying this disease has been elucidated in the past few years. Research shows that psoriasis is regulated by the complex interactions among immune cells, such as keratinocytes, dendritic cells, T lymphocytes, neutrophils, macrophages, natural killer cells, mast cells, and other immune cells. An increasing number of signaling pathways have been found to be involved in the pathogenesis of psoriasis, which has prompted the search for new treatment targets. In the past decades, studies on the pathogenesis of psoriasis have focused on the development of targeted and highly effective therapies. In this review, we have discussed the relationship between various types of immune cells and psoriasis and summarized the major signaling pathways involved in the pathogenesis of psoriasis, including the PI3K/AKT/mTOR, JAK-STAT, JNK, and WNT pathways. In addition, we have discussed the results of the latest omics research on psoriasis and the epigenetics of the disease, which provide insights regarding its pathogenesis and therapeutic prospects; we have also summarized its treatment strategies and observations of clinical trials. In this paper, the various aspects of psoriasis are described in detail, and the limitations of the current treatment methods are emphasized. It is necessary to improve and innovate treatment methods from the molecular level of pathogenesis, and further provide new ideas for the treatment and research of psoriasis.

The Role of T Helper 22 Cells in Dermatological Disorders

T helper 22 (Th22) cells are a newly identified subset of CD4+ T cells that secrete the effector cytokine interleukin 22 (IL-22) upon specific antigen stimulation, barely with IFN-γ or IL-17. Increasing studies have demonstrated that Th22 cells and IL-22 play essential roles in skin barrier defense and skin disease pathogenesis since the IL-22 receptor is widely expressed in the skin, especially in keratinocytes. Herein, we reviewed the characterization, differentiation, and biological activities of Th22 cells and elucidated their roles in skin health and disease. We mainly focused on the intricate crosstalk between Th22 cells and keratinocytes and provided potential therapeutic strategies targeting the Th22/IL-22 signaling pathway.

Circ_0060531 knockdown ameliorates IL-22-induced keratinocyte damage by binding to miR-330-5p to decrease GAB1 expression

BACKGROUND

Psoriasis is a chronic immune-mediated skin disease. Recent studies showed its pathogenesis involved circular RNA (circRNA). However, the role of circ_0060531 in psoriasis development and the behind mechanism remain to be explored.

METHODS

Psoriasis cell model was constructed by treating keratinocytes (HaCaT cells) using interleukin 22 (IL-22). Expression of circ_0060531, microRNA-330-5p (miR-330-5p) and GRB2 associated binder 1 (GAB1) was determined by quantitative real-time polymerase chain reaction. The functional effects of circ_0060531 on IL-22-caused cell injury were investigated by 3-(4,5-Dimethylthazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-Ethynyl-29-deoxyuridine, wound-healing and enzyme-linked immunosorbent assays. Protein expression was analysed by Western blot. The interactions among circ_0060531, miR-330-5p and GAB1 were identified by dual-luciferase reporter or RNA immunoprecipitation assay.

RESULTS

Circ_0060531 and GAB1 expression were significantly increased, while miR-330-5p was decreased in psoriatic skin biopsies and IL-22-stimulated HaCaT cells in comparison with controls. In function, circ_0060531 knockdown assuaged IL-22-induced cell proliferation, cell migration and inflammation. Besides, circ_0060531 acted as a miR-330-5p sponge, and regulated the processes of IL-22-treated HaCaT cells by binding to the miRNA. Under the treatment of IL-22, miR-330-5p mediated HaCaT cell damage by targeting GAB1. Importantly, circ_0060531 modulated GAB1 production by interacting with miR-330-5p.

CONCLUSION

Circ_0060531 knockdown assuaged IL-22-induced keratinocyte dysfunction through miR-330-5p/GAB1 pathway, proving a novel target for the therapy of psoriasis.

LncRNA MALAT-1 regulates the growth of interleukin-22-stimulated keratinocytes via the miR-330-5p/S100A7 axis

Psoriasis is a chronic autoimmune disorder related to abnormal keratinocyte proliferation. Long noncoding RNAs (lncRNAs) are significant regulators in the progression of skin diseases. In this study, we explored how lncRNA MALAT-1 controls the pathogenesis of psoriasis by examining its impact on keratinocyte proliferation, inflammation, and apoptosis. A psoriasis cell model was established by treating HaCaT keratinocytes with the inflammatory factor, IL-22 (100 ng/ml), for 24 h. The MALAT-1 and S100A7 levels in psoriatic lesions, normal skin tissues, and IL-22-stimulated HaCaT cells were determined by RT-qPCR and western blotting. Cell proliferation, inflammation, and apoptosis were detected by the MTT assay, western blotting, and flow cytometry analysis, respectively. Bioinformatics analysis was used to identify the miRNAs that bind to MALAT-1 and S100A7. The relationships between MALAT-1 or miR-330-5p and S100A7 were assessed using a luciferase reporter assay. The MALAT-1 and S100A7 levels were upregulated in both psoriatic lesion samples and IL-22-stimulated HaCaT cells. Silencing MALAT-1 significantly reversed the IL-22-stimulated promotion of HaCaT proliferation and changes in Ki67 and KRT5/14/1/10 protein levels, and MALAT-1 deficiency also reversed the upregulation of TNF-α, IL-17, and IL-23 protein levels as well as suppression of cell apoptosis. As a ceRNA, MALAT-1 competed with S100A7 to prevent miR-330-5p-induced inhibition of S100A7 expression. There was a negative correlation between miR-330-5p and MALAT-1 (or S100A7) expression in psoriatic lesion tissues. In response to IL-22 treatment, miR-330-5p silencing eliminated the effects of MALAT-1 knockdown in HaCaT cells. Thus, these findings demonstrated that MALAT-1 modulates the IL-22-induced changes in HaCaT cells through the miR-330-5p/S100A7 axis.

Advances in the pathogenesis of psoriasis: from keratinocyte perspective

Psoriasis is a complex long-lasting inflammatory skin disease with high prevalence and associated comorbidity. It is characterized by epidermal hyperplasia and dermal infiltration of immune cells. Here, we review the role of keratinocytes in the pathogenesis of psoriasis, focusing on factors relevant to genetics, cytokines and receptors, metabolism, cell signaling, transcription factors, non-coding RNAs, antimicrobial peptides, and proteins with other different functions. The critical role of keratinocytes in initiating and maintaining the inflammatory state suggests the great significance of targeting keratinocytes for the treatment of psoriasis.

Decreased microRNA-126 expression in psoriatic CD4+ T cells promotes T-helper 17 cell differentiation and the formation of dermatitis in imiquimod-induced psoriasis-like mice

Psoriasis is a chronic inflammatory skin disease with multiple genetic backgrounds, whose etiology and pathogenesis are still unclear. Complex T-cell immune imbalance has been demonstrated to play an important role in pathogenesis of psoriasis. This study reported that microRNA-126 (miR-126) expression was decreased in CD4⁺ T cells of both psoriasis patients and psoriasis-like mouse models and its expression was negatively correlated with the Psoriasis Area and Severity Index (PASI) score of psoriasis patients. Conditional Mir126 knockout in mouse CD4⁺ T cells can obviously aggravate the psoriasis-like dermatitis and promote T-helper (Th)1 and Th17 cells' infiltration in spleen of imiquimod (IMQ)-induced psoriasis-like mouse model. In addition, the mRNA expression of Il17a and Il17f were significantly increased in mouse naïve CD4⁺ T cells with Mir126 knockout after stimulating with CD3 and CD28. Compared with naïve CD4⁺ T cells, the expression of Mir126 was decreased in Th17 cells, and Mir126 knockout notably promoted the differentiation of naïve CD4⁺ T cells to Th17 cells as well as the mRNA expression of Il17a, Il17f, Rorc, and Il23R. Our results revealed that decreased miR-126 in psoriatic CD4⁺ T cells might accelerate the formation of skin lesions through promoting the differentiation of Th17 cells, thus suggesting a potential intervention target for psoriasis.

Dysregulated epigenetic modifications in psoriasis

The observed incidence of psoriasis has been gradually increasing over time (J Am Acad Dermatol, 03, 2009, 394), but the underlying pathogenic factors have remained unclear. Recent studies suggest the importance of epigenetic modification in the pathogenesis of psoriasis. Aberrant epigenetic patterns including changes in DNA methylation, histone modifications and non-coding RNA expression are observed in psoriatic skin. Reversing these epigenetic mechanisms has showed improvement in psoriatic phenotypes, making epigenetic therapy a potential avenue for psoriasis treatment. Here, we summarize relevant evidence for epigenetic dysregulation contributing to psoriasis susceptibility and pathogenesis, and the factors responsible for epigenetic modifications, providing directions for potential future clinical avenues.

Kochia scoparia Saponin Momordin Ic Modulates HaCaT Cell Proliferation and Apoptosis via the Wnt/β-Catenin Pathway

Psoriasis is a chronic, recurrent, immunoinflammatory disease. For a long period, Traditional Chinese Medicine (TCM) is considered a reliable alternative therapy for patients with psoriasis. Fructus Kochiae (or Kochia scoparia) and its principle saponin, Momordin Ic, have been reported to protect against inflammation. Herein, we demonstrated that Momordin Ic could inhibit HaCaT cell proliferation and enhance cell apoptosis. In the meantime, Momordin Ic alters Wnt/β-catenin pathway activation by affecting β-catenin nuclear distribution. The Wnt/β-catenin signaling activator LiCl partially reversed the effects of Momordin Ic on HaCaT phenotypes and the Wnt/β-catenin pathway factors. Altogether, we demonstrate the inhibitory effects of Momordin Ic, one of the major saponin constituents of Fructus Kochiae, on HaCaT cell proliferation and Momordin Ic-induced alteration within the Wnt/β-catenin pathway. Momordin Ic might act on HaCaT cells by modulating the Wnt/β-catenin pathway.

MicroRNA-126-5p Regulates Proliferation and Apoptosis of IL-22-Stimulated Human Keratinocytes Through Regulating Caspase 1

Objective: The study was aimed to explore the roles of miR-126-5p in psoriasis and the underlying molecular mechanisms. Methods: In vitro cell model of psoriasis was established by IL-22 induction. CASP1, the target gene of miR-126-5p, was predicted by TargetScan and verified through the dual luciferase reporter gene system. qRT-PCR was used to measure the mRNA expression of miR-126-5p and CASP1 in IL-22 stimulated HaCaT cells. The protein expression of CASP1, cleaved-caspase3 and caspase3 were measured by Western blot analysis. MTT assay and flow cytometry analysis were performed to detect the cell proliferation and apoptosis. A Caspase3 Activity Assay kit was used to detect the activity of Caspase3. Results: miR-126-5p was high expressed in IL-22 stimulated HaCaT cells compared with normal HaCaT cells. We predicted and verified that CASP1 was a direct target of miR-126-5p, and the mRNA and protein expression of CASP1 were reduced in IL-22 stimulated HaCaT cells compared with the normal HaCaT cells. miR-126-5p inhibitor and CASP1-siRNA significantly decreased the expression of miR-126-5p and CASP1 in HaCaT cells respectively. miR-126-5p inhibitor up-regulated the expression of CASP1 in HaCaT cells, and the effect was reversed by the transfection with CASP1-siRNA. In comparison with the control group, miR-126-5p inhibitor decreased the cell proliferation, induced apoptosis, and improved the activity of Caspase3, enhanced cleaved-caspase3/caspase3 ratio in IL-22 stimulated HaCaT cells, and all the effects were reversed by down-regulating CASP1. Conclusion: We demonstrated that miR-126-5p inhibitor played a protective role in psoriasis by targeting CASP1, evidenced by inhibiting IL-22-induced HaCaT cell proliferation and inducing apoptosis.

Insights into interplay of immunopathophysiological events and molecular mechanistic cascades in psoriasis and its associated comorbidities

Psoriasis is an inflammatory skin disease with complex pathogenesis and multiple etiological factors. Besides the essential role of autoreactive T cells and constellation of cytokines, the discovery of IL-23/Th17 axis as a central signaling pathway has unraveled the mechanism of accelerated inflammation in psoriasis. This has provided insights into psoriasis pathogenesis and revolutionized the development of effective biological therapies. Moreover, genome-wide association studies have identified several candidate genes and susceptibility loci associated with this disease. Although involvement of cellular innate and adaptive immune responses and dysregulation of immune cells have been implicated in psoriasis initiation and maintenance, there is still a lack of unifying mechanism for understanding the pathogenesis of this disease. Emerging evidence suggests that psoriasis is a high-mortality disease with additional burden of comorbidities, which adversely affects the treatment response and overall quality of life of patients. Furthermore, changing trends of psoriasis-associated comorbidities and shared patterns of genetic susceptibility, risk factors and pathophysiological mechanisms manifest psoriasis as a multifactorial systemic disease. This review highlights the recent progress in understanding the crucial role of different immune cells, proinflammatory cytokines and microRNAs in psoriasis pathogenesis. In addition, we comprehensively discuss the involvement of various complex signaling pathways and their interplay with immune cell markers to comprehend the underlying pathophysiological mechanism, which may lead to exploration of new therapeutic targets and development of novel treatment strategies to reduce the disastrous nature of psoriasis and associated comorbidities.

Weighted gene coexpression network and experimental analyses identify lncRNA SPRR2C as a regulator of the IL-22-stimulated HaCaT cell phenotype through the miR-330/STAT1/S100A7 axis

Psoriasis is a chronic inflammatory disease of the skin with highly complex pathogenesis. In this study, we identified lncRNA SPRR2C (small proline-rich protein 2C) as a hub gene with a critical effect on the pathogenesis of psoriasis and response to treatment using both weighted gene coexpression network analysis (WGCNA) and differential expression analysis. SPRR2C expression was significantly upregulated in both psoriatic lesion samples and HaCaT cell lines in response to IL-22 treatment. After SPRR2C knockdown, IL-22-induced suppression of HaCaT proliferation, changes in the KRT5/14/1/10 protein levels, and suppression of the IL-1β, IL-6, and TNF-α mRNA levels were dramatically reversed. In the coexpression network with SPRR2C based on GSE114286, miR-330 was significantly negatively correlated with SPRR2C, while STAT1 and S100A7 were positively correlated with SPRR2C. By binding to miR-330, SPRR2C competed with STAT1 and S100A7 to counteract miR-330-mediated suppression of STAT1 and S100A7. MiR-330 overexpression also reversed the IL-22-induced changes in HaCaT cell lines; in response to IL-22 treatment, miR-330 inhibition significantly attenuated the effects of SPRR2C knockdown. STAT1 and S100A7 expression was significantly upregulated in psoriatic lesion samples. The expression of miR-330 had a negative correlation with the expression of SPRR2C, while the expression of SPRR2C had a positive correlation with the expression of STAT1 and S100A7. Thus, SPRR2C modulates the IL-22-stimulated HaCaT cell phenotype through the miR-330/STAT1/S100A7 axis. WGCNA might uncover additional biological pathways that are crucial in the pathogenesis and response to the treatment of psoriasis.

The Role of MicroRNAs in Epidermal Barrier

MicroRNAs (miRNAs), which mostly cause target gene silencing via transcriptional repression and degradation of target mRNAs, regulate a plethora of cellular activities, such as cell growth, differentiation, development, and apoptosis. In the case of skin keratinocytes, the role of miRNA in epidermal barrier integrity has been identified. Based on the impact of key genetic and environmental factors on the integrity and maintenance of skin barrier, the association of miRNAs within epidermal cell differentiation and proliferation, cell-cell adhesion, and skin lipids is reviewed. The critical role of miRNAs in the epidermal barrier extends the use of miRNAs for control of relevant skin diseases such as atopic dermatitis, ichthyoses, and psoriasis via miRNA-based technologies. Most of the relevant miRNAs have been associated with keratinocyte differentiation and proliferation. Few studies have investigated the association of miRNAs with structural proteins of corneocytes and cornified envelopes, cell-cell adhesion, and skin lipids. Further studies investigating the association between regulatory and structural components of epidermal barrier and miRNAs are needed to elucidate the role of miRNAs in epidermal barrier integrity and their clinical implications.

Triptolide Inhibits the Proliferation of HaCaT Cells Induced by IL22 via Upregulating miR-181b-5p

BACKGROUND

Evidence has been shown that triptolide was effective in the treatment of psoriasis; however, the mechanisms remain poorly understood. Thus, this study aimed to investigate the role of triptolide on the proliferation and differentiation of HaCaT cells which are treated with IL22 to mimic abnormal proliferation/differentiation in keratinocyte of psoriasis.

MATERIALS AND METHODS

HaCaT cells were transfected with miR-181b-5p antagomir for 24 h, and then exposed to 10 μM Triptolide for 24 h, following by 100 ng/mL of IL22 for 24 h. In addition, the proliferation and cell cycle distribution in HaCaT cells were assessed by immunofluorescence or flow cytometry assays, respectively.

RESULTS

Triptolide obviously upregulated the level of miR-181b-5p in HaCaT cells. In addition, triptolide significantly inhibited IL22-induced proliferation of HaCaT cells via inducing cell cycle arrest. Moreover, IL22 markedly inhibited the differentiation of HaCaT cells, and this phenomenon was reversed by triptolide treatment. In contrast, the effects of triptolide on the proliferation and differentiation in IL22-stimulated HaCaT cells were notably reversed by miR-181b-5p antagomir. Moreover, dual-luciferase assay showed that E2F5 was the direct target of miR-181b-5p in HaCaT cells. Meanwhile, upregulation of miR-181b-5p obviously decreased the level of E2F5 in HaCaT cells.

CONCLUSION

In this study, we found that triptolide could inhibit the proliferation and promote the differentiation in IL22-stimulated keratinocytes via upregulating miR-181b-5p. These data indicated that triptolide may be a potential agent for the treatment of psoriasis.

miR-183-3p suppresses proliferation and migration of keratinocyte in psoriasis by inhibiting GAB1

Background

MicroRNAs (miRNAs) target genes involved in the hyperproliferation of keratinocytes or immune dysfunction of psoriasis. This study prospectively determined the involvement of miR-183-3p in the pathogenesis of psoriasis.

Methods

Differentially expressed miR-183-3p between psoriatic lesional and non-lesional skin were determined by quantitative RT-PCR and in situ hybridization (ISH). CCK8 and wound healing assays were performed to assess cell viability and migration of human keratinocyte cell line (HaCaT). The target of miR-183-3p was validated by luciferase activity assay.

Results

Lower miR-183-3p expression was observed in psoriatic lesional skin compared to psoriatic non-lesional skin. MiR-183-3p over-expression inhibited the viability and migration of HaCaT cells, while inhibition of miR-183-3p promoted the viability and migration of HaCaT cells. Moreover, miR-183-3p could bind to the 3′ UTR of GAB1 (growth factor receptor binding 2-associated binding protein 1) and decrease the mRNA and protein expression of GAB1 in HaCaT cells. In addition, higher GAB1 expression was observed in psoriatic lesional skin than psoriatic non-lesional skin.

Conclusion

MiR-183-3p exhibited inhibition property in the proliferation and migration of HaCaT cells via down-regulation of GAB1, suggesting the potential therapeutic strategy for psoriasis.

MiR-223 regulates proliferation and apoptosis of IL-22-stimulated HaCat human keratinocyte cell lines via the PTEN/Akt pathway

Psoriasis, a chronic inflammatory skin disorder disease, is closely associated with hyperproliferation of keratinocytes. Upregulated miR-223 has been found in peripheral blood mononuclear cells from patients with psoriasis and from psoriatic skin. However, its role in keratinocytes remains unknown. We thus aimed to investigate the function of miR-223 in psoriasis. Interleukin-22 (IL-22) is a crucial keratinocyte trigger in the T-cell-mediated immune response to psoriasis. We found miR-223 to be overexpressed in psoriatic lesions and in IL-22-stimulated HaCaT cells. HaCaT cells then were transfected with a miR-223 mimic or inhibitor to overexpress or inhibit expression of miR-223, respectively. A Cell Counting Kit-8 assay revealed that miR-223 overexpression promoted and miR-223 downregulation inhibited proliferation in IL-22-stimulated HaCaT cells. Flow cytometry analysis certified that miR-223 overexpression decreased HaCaT cell apoptosis, whereas miR-223 downregulation increased it. A dual-luciferase reporter assay demonstrated that miR-223 directly targeted the phosphatase and tensin homolog (PTEN) gene. MiR-223 also negatively regulated mRNA and protein expression of PTEN and modulated the PTEN/Akt pathway in IL-22-stimulated HaCaT cells. PTEN silencing attenuated the activity of the miR-223 inhibitor in these cells via the PTEN/Akt pathway. Overall, the results showed that miR-223 increased proliferation and inhibited apoptosis of IL-22-stimulated keratinocytes via the PTEN/Akt pathway.

FGF19 sustains the high proliferative ability of keratinocytes in psoriasis through the regulation of Wnt/GSK-3β/β-catenin signalling via FGFR4

Accumulating evidence has shown that fibroblast growth factor 19 (FGF19) plays an important role in regulating cell proliferation. Psoriasis is characterized by the hyperproliferation of keratinocytes in skin lesions. However, whether FGF19 regulates the proliferation of keratinocytes in psoriasis remains unknown. In this study, we aimed to explore the potential relevance of FGF19 in psoriasis. We found that FGF19 was highly expressed in psoriatic skin from psoriasis patients, as well as keratinocytes that were stimulated with a cocktail of cytokines (M5), which is an in vitro model of psoriasis. Functional experiments demonstrated that FGF19 overexpression promoted the growth and proliferation of keratinocytes, while FGF19 knockdown showed opposite effect. Moreover, we found that FGF19 increased the phosphorylation of glycogen synthase kinase (GSK)-3β and promoted the expression of β-catenin and the activation of T cell factor 4 (TCF4) transcriptional activity. Notably, blocking Wnt/β-catenin signalling by silencing β-catenin partially reversed FGF19-mediated promotional effects on keratinocyte proliferation. In addition, FGFR4 inhibition significantly blocked the promotional effect of FGF19 on keratinocyte proliferation and GSK-3β/β-catenin/TCF4 signalling. Taken together, our results demonstrated that FGF19 contributes to sustaining the high proliferative ability of keratinocytes through promoting Wnt/GSK-3β/β-catenin signalling via FGFR4, highlighting the importance of FGF19 in the pathogenesis of psoriasis. Our study suggests that FGF19 may serve as a novel and potential therapeutic target for psoriasis.

MicroRNA let-7b inhibits keratinocyte differentiation by targeting IL-6 mediated ERK signaling in psoriasis

Background

The extensive involvement of microRNA (miRNA) in the pathophysiology of psoriasis is well documented. However, in order for this information to be useful in therapeutic manipulation of miRNA levels, it is essential that detailed functional mechanisms are elucidated. This study aimed to explore the effects of IL-6 targeting by let-7b and ERK1/2 mediated signaling on keratinocyte differentiation in psoriasis.

Methods

Following imiquimod cream (IMQ) application to let-7b^TG (keratinocyte-specific let-7b overexpression mouse) and control mice for 7 days, we analyzed erythema, scaling and thickening of skin. A dual luciferase reporter assay and bioinformatics was carried out to detect target gene of let-7b. Additionally, the differentiation markers were measured. Immunohistochemistry analyses demonstrate a relationship of let-7b with IL-6 and ERK signaling.

Results

we found let-7b^TG inhibits acanthosis and reduces the disease severity by treatment with IMQ compared to wild-type mice. Further study illustrated that let-7b promotes differentiation of keratinocytes in vivo and in vitro. Using bioinformatics and reporter gene assays, we found that IL-6 is a target gene of let-7b. In psoriasis, high expression levels of IL-6 lead to increased acivation of p-ERK1/2. High levels of let-7b^TG transgene expression suppresses IL-6 expression and leads to increased keratinocyte differentiation. Moreover, let-7b acts as an upstream negative regulator of the ERK signaling pathway in keratinocytes of psoriasis.

Conclusions

Our result reveals a previously unknown mechanism for regulation of IL-6 levels during psoriasis by let-7b and highlights a critical role for the ERK1/2 signaling pathway in epidermal differentiation during psoriasis.

Trial registration

The ethical approval for this study was from the Affiliated Hospital of Medical University of Anhui _ Fast_ PJ2017–11–14.

Electronic supplementary material

The online version of this article (10.1186/s12964-018-0271-9) contains supplementary material, which is available to authorized users.

MiR-20a-3p regulates TGF-β1/Survivin pathway to affect keratinocytes proliferation and apoptosis by targeting SFMBT1 in vitro

Psoriasis is a common immune-mediated chronic inflammatory skin disease characterized by abnormal keratinocyte proliferation, differentiation and apoptosis. However, the exact etiology and pathogenesis are still unclear. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. It has been demonstrated that Interleukin-22 (IL-22) plays vital role in T cell-mediated immune response by interacting with keratinocytes in the pathogenesis of psoriasis. The aim of our study was to explore the possible functional role of miR-20a-3p in psoriasis and in IL-22 induced keratinocyte proliferation. Here, we found that miR-20a-3p was down-regulated in psoriatic lesions and in HaCaT cells (human keratinocyte cell line) treated by IL-22 stimulation. Functional experiments showed that overexpression of miR-20a-3p in HaCaT cells suppressed proliferation and induced apoptosis while its knockdown promoted cell proliferation and reduces cell apoptosis. Mechanistically, SFMBT1 was identified as the direct target of miR-20a-3p by dual luciferase reporter assay. SFMBT1 knockdown was demonstrated to inhibit cell growth and induced apoptosis, which was consistent with the function of miR-20a-3p upregulation in HaCaT cells. In addition, results of western blot analysis showed that miR-20a-3p upregulation or SFMBT1 knockdown changed the protein expression levels of TGF-β1 and survivin. Our findings suggest that miR-20a-3p play roles through targeting SFMBT1 and TGF-β1/Survivin pathway in HaCaT cells, and loss of miR-20a-3p in psoriasis may contribute to hyperproliferation and aberrant apoptosis of keratinocytes.

MicroRNA-210 overexpression promotes psoriasis-like inflammation by inducing Th1 and Th17 cell differentiation

Immune imbalance of T lymphocyte subsets is a hallmark of psoriasis, but the molecular mechanisms underlying this aspect of psoriasis pathology are poorly understood. Here, we report that microRNA-210 (miR-210), a miR that is highly expressed in both psoriasis patients and mouse models, induces helper T (Th) 17 and Th1 cell differentiation but inhibits Th2 differentiation through repressing STAT6 and LYN expression, contributing to several aspects of the immune imbalance in psoriasis. Both miR-210 ablation in mice and inhibition of miR-210 by intradermal injection of antagomir-210 blocked the immune imbalance and the development of psoriasis-like inflammation in an imiquimod-induced or IL-23-induced psoriasis-like mouse model. We further showed that TGF-β and IL-23 enhance miR-210 expression by inducing HIF-1α, which recruits P300 and promotes histone H3 acetylation in the miR-210 promoter region. Our results reveal a crucial role for miR-210 in the immune imbalance of T lymphocyte subsets in psoriasis and suggest a potential therapeutic avenue.