MicroRNAs and potential target interactions in psoriasis

Genome-wide RNA-seq, DNA methylation and small RNA-seq analysis unraveled complex gene regulatory networks in psoriasis pathogenesis

Psoriasis is a complex inflammatory skin disease characterized by reversible albeit relapsing red scaly plaques in the skin of a patient. In addition to the genetic predisposition, involvement of epigenetic and non-coding RNAs have also been liked with the disease. Nevertheless, any comprehensive study involving transcriptomic, small-RNA and DNA methylation at the genomic level from same patients is lacking. To investigate the complex regulation of molecular pathways in psoriasis, we carried out multi-omics integrative analysis of RNA-sequencing, small RNA-sequencing and DNA methylation profiling from the psoriatic and adjacent normal skin tissues. Our multi-omics analysis identified the genes and biological processes regulated either independently or in combination by DNA methylation and microRNAs. We identified miRNAs that specifically regulated keratinocyte hyper-proliferation, and cell cycle progression and checkpoint signaling in psoriasis. On contrary, DNA methylation was found to be more predominant in regulating immune and inflammatory responses, another causative factor in psoriasis pathogenesis. Many characteristic pathways in psoriasis e.g., Th17 cell differentiation and JAK-STAT signaling, were found to be regulated by both miRNAs and DNA methylation. We carried out functional characterization of a downregulated miRNA hsa-let-7c-5p, predicted to target upregulated genes in psoriasis involved in cell cycle processes, Th17 cell differentiation and JAK-STAT signaling pathways. Overexpression of hsa-let-7c-5p in keratinocytes caused the downregulation of its target genes, resulting in reduced cell proliferation and migration rates, demonstrating potential of miRNAs in regulating psoriasis pathogenesis. In conclusion, our findings identified distinct and shared gene-networks regulated by DNA methylation and miRNAs of a complex disease with reversible phenotype.

NETosis of psoriasis: a critical step in amplifying the inflammatory response

NETosis, a regulated form of neutrophil death, is crucial for host defense against pathogens. However, the release of neutrophil extracellular traps (NETs) during NETosis can have detrimental effects on surrounding tissues and contribute to the pro-inflammatory response, in addition to their role in controlling microbes. Although it is well-established that the IL-23-Th17 axis plays a key role in the pathogenesis of psoriasis, emerging evidence suggests that psoriasis, as an autoinflammatory disease, is also associated with NETosis. The purpose of this review is to provide a comprehensive understanding of the mechanisms underlying NETosis in psoriasis. It will cover topics such as the formation of NETs, immune cells involved in NETosis, and potential biomarkers as prognostic/predicting factors in psoriasis. By analyzing the intricate relationship between NETosis and psoriasis, this review also aims to identify novel possibilities targeting NETosis for the treatment of psoriasis.

Neutrophil-Derived MicroRNA-1290 Promotes Keratinocyte Proliferation in Psoriasis

The pathological hallmark of psoriasis is the infiltration of neutrophils into the skin. Some neutrophil-derived microRNAs (miRNAs) serve as biomarkers for various diseases, but none have been reported for psoriasis. In this study, we investigated the involvement of miRNAs released from neutrophils in psoriasis pathogenesis. We compared the expression of miRNAs in the sera of patients with psoriasis with that in healthy individuals and found that the expression of 2 miRNAs-miR-223 and miR-1290-was significantly upregulated in the sera of patients with psoriasis. The serum levels of these miRNAs positively correlated with the PASI and CRP levels. We used all-trans retinoic acid to induce the differentiation of human promyelocytic leukemia HL-60 cells into neutrophil-like cells and found that the release of both miRNAs increased during differentiation. Furthermore, the release of miR-1290 was increased by TNF-α in neutrophil-like cells and human neutrophils. Treatment with the miR-1290 precursor promoted the proliferation of human keratinocytes, increased the proportion of S-phase cells, and upregulated the phosphorylation of extracellular signal-regulated kinase 1/2. These results suggest that miR-1290 plays a vital role in regulating neutrophil differentiation and keratinocyte proliferation and could be a serum marker of psoriasis severity.

Upregulated miR-374a-5p drives psoriasis pathogenesis through WIF1 downregulation and Wnt5a/NF-κB activation

BACKGROUND

Psoriasis is a chronic, inflammatory skin disease. MicroRNAs (miRNAs) are an abundant class of non-coding RNA molecules. Recent studies have shown that multiple miRNAs are abnormally expressed in patients with psoriasis. The upregulation of miR-374a-5p has been associated with psoriasis severity. However, the specific role of miR-374a-5p in the pathogenesis of psoriasis remain unclear.

METHODS

qRT-PCR was employed to validate the expression of miR-374a-5p in psoriatic lesions and in a psoriasis-like cell model constructed using a mixture of M5 (IL-17A, IL-22, OSM, IL-1α, and TNF-α). HaCaT cells were transfected with miR-374a-5p mimic/inhibitor, and assays including EdU, CCK-8, and flow cytometry were conducted to evaluate the effect of miR-374a-5p on cell proliferation. The expression of inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α was verified by qRT-PCR. Bioinformatics analysis and dual-luciferase reporter gene assay were performed to detect the downstream target genes and upstream transcription factors of miR-374a-5p, followed by validation of their expression through qRT-PCR and Western blotting. A psoriasis-like mouse model was established using imiquimod cream topical application. The psoriasis area and severity index scoring, hematoxylin-eosin histology staining, and Ki67 immunohistochemistry were employed to validate the effect of miR-374a-5p on the psoriatic inflammation phenotype after intradermal injection of miR-374a-5p agomir/NC. Additionally, the expression of pathway-related molecules and inflammatory factors such as IL-1β, IL-17a, and TNF-α was verified by immunohistochemistry.

RESULTS

Upregulation of miR-374a-5p was observed in psoriatic lesions and the psoriasis-like cell model. In vitro experiments demonstrated that miR-374a-5p not only promoted the proliferation of HaCaT cells but also upregulated the expression of inflammatory cytokines, including IL-1β, IL-6, IL-8, and TNF-α. Furthermore, miR-374a-5p promoted skin inflammation and epidermal thickening in the Imiquimod-induced psoriasis-like mouse model. Mechanistic studies revealed that miR-374a-5p led to downregulation of WIF1, thereby activating the Wnt5a/NF-κB signaling pathway. The transcription factor p65 encoded by RELA, as a subunit of NF-κB, further upregulated the expression of miR-374a-5p upon activation. This positive feedback loop promoted keratinocyte proliferation and abnormal inflammation, thereby facilitating the development of psoriasis.

CONCLUSION

Our findings elucidate the role of miR-374a-5p upregulation in the pathogenesis of psoriasis through inhibition of WIF1 and activation of the Wnt5a/NF-κB pathway, providing new potential therapeutic targets for psoriasis.

A Review of MicroRNAs and lncRNAs in Atherosclerosis as Well as Some Major Inflammatory Conditions Affecting Atherosclerosis

It is generally accepted that atherosclerosis is a chronic inflammatory disease. The link between atherosclerosis and other inflammatory diseases such as psoriasis, type 2 diabetes mellitus (T2DM), and rheumatoid arthritis (RA) via metabolic, inflammatory, and immunoregulatory pathways is well established. The aim of our review was to summarize the associations between selected microRNAs (miRs) and long non-coding RNAs (lncRNAs) and atherosclerosis, psoriasis, T2DM, and RA. We reviewed the role of miR-146a, miR-210, miR-143, miR-223, miR-126, miR-21, miR-155, miR-145, miR-200, miR-133, miR-135, miR-221, miR-424, let-7, lncRNA-H19, lncRNA-MEG3, lncRNA-UCA1, and lncRNA-XIST in atherosclerosis and psoriasis, T2DM, and RA. Extracellular vesicles (EVs) are a method of intracellular signal transduction. Their function depends on surface expression, cargo, and the cell from which they originate. The majority of the studies that investigated lncRNAs and some miRs had relatively small sample sizes, which limits the generalizability of their findings and indicates the need for more research. Based on the studies reviewed, miR-146a, miR-155, miR-145, miR-200, miR-133, and lncRNA-H19 are the most promising potential biomarkers and, possibly, therapeutic targets for atherosclerosis as well as T2DM, RA, and psoriasis.

miR-181a/b-5p negatively regulates keratinocytes proliferation by targeting MELK

Accumulating evidence indicates that microRNAs (miRNAs) have a vital effect on the pathogenesis of psoriasis. This study is conducted to investigate the potential involvement of miR-181a-5p and miR-181b-5p in the proliferation of HaCaT keratinocytes. Cell viability and proliferation were evaluated respectively in this study using the CCK-8 and the 5-ethynyl-2'-deoxyuridine (EdU) assays. The expression of Maternal Embryonic Leucine Zipper Kinase (MELK) and Keratin 16 (KRT16) mRNA and protein in tissues and cells was assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The Luciferase reporter system analyzes the connection between miR-181a-5p/miR-181b-5p and MELK. The results showed that miR-181a/b-5p expression was downregulated in the psoriasis lesions and negatively regulated the proliferation of keratinocytes. MELK was directly targeted by miR-181a-5p/miR-181b-5p. In addition, HaCaT keratinocytes proliferation was inhibited by knockdown of MELK while promoted dramatically by MELK overexpression. Notably, miR-181a/b-5p mimics could attenuate the effects of MELK in keratinocytes. In conclusion, our research findings suggested miR-181a-5p and miR-181b-5p negatively regulate keratinocyte proliferation by targeting MELK, providing potential diagnostic biomarkers and therapeutic targets for psoriasis.

The Functional Roles of the Src Homology 2 Domain-Containing Inositol 5-Phosphatases SHIP1 and SHIP2 in the Pathogenesis of Human Diseases

The src homology 2 domain-containing inositol 5-phosphatases SHIP1 and SHIP2 are two proteins involved in intracellular signaling pathways and have been linked to the pathogenesis of several diseases. Both protein paralogs are well known for their involvement in the formation of various kinds of cancer. SHIP1, which is expressed predominantly in hematopoietic cells, has been implicated as a tumor suppressor in leukemogenesis especially in myeloid leukemia, whereas SHIP2, which is expressed ubiquitously, has been implicated as an oncogene in a wider variety of cancer types and is suggested to be involved in the process of metastasis of carcinoma cells. However, there are numerous other diseases, such as inflammatory diseases as well as allergic responses, Alzheimer's disease, and stroke, in which SHIP1 can play a role. Moreover, SHIP2 overexpression was shown to correlate with opsismodysplasia and Alzheimer's disease, as well as metabolic diseases. The SHIP1-inhibitor 3-α-aminocholestane (3AC), and SHIP1-activators, such as AQX-435 and AQX-1125, and SHIP2-inhibitors, such as K161 and AS1949490, have been developed and partly tested in clinical trials, which indicates the importance of the SHIP-paralogs as possible targets in the therapy of those diseases. The aim of this article is to provide an overview of the current knowledge about the involvement of SHIP proteins in the pathogenesis of cancer and other human diseases and to create awareness that SHIP1 and SHIP2 are more than just tumor suppressors and oncogenes.

Protective effect and regulatory mechanism of salidroside on skin inflammation induced by imiquimod in psoriasis mice

Salidroside (SAL) is a glucoside of tyrosol commonly existing in the roots of Rhodiola rosea. This study unveils the protective effect of SAL on skin inflammation in imiquimod (IMQ)-induced psoriasis. The mouse model of psoriasis was established by local application of IMQ, and SAL efficacy was evaluated through PASI scoring, H&E staining, and skin tissue pathology observation. The HaCaT cell model was established by interferon (IFN)-γ induction, followed by MTT assay detection of cell viability, detection of ROS, SOD, MDA, and CAT levels in skin tissues and cells using reagent kits, ELISA detection of inflammatory factors (TNF-α, IL-6, IL-1β), and qRT-PCR detection of psoriasis-related genes (S100a9, Cxcl1, Cxcl2) as well as miR-369-3p and SMAD2 expressions. The binding relationship between miR-369-3p and SMAD2 was validated using dual-luciferase reporter assay. SAL treatment reduced PASI scores and alleviated psoriasis symptoms of IMQ-induced mice, and also augmented the viability and subsided the oxidative stress and inflammation of IFN-γ-treated HaCaT cells. SAL treatment restrained miR-369-3p expression but elevated SMAD2 expression. Mechanistically, miR-369-3p targeted SMAD2 expression. miR-369-3p overexpression or SMAD2 inhibition partially offset the alleviating effect of SAL on psoriasis skin inflammation. In conclusion, SAL alleviates skin inflammation in IMQ-induced psoriasis mice via the miR-369-3p/SMAD2 axis.

Is Mir-205 a possible biomarker for evaluating treatment response in psoriasis?

Psoriasis is a chronic skin disease that affects a significant number of patients and can severely impair quality of life. Although the diagnosis is normally clinical, paraclinical determination can occasionally be useful either in differential diagnosis or in evaluating the inflammatory response to treatment. MicroRNAs (miRNAs) are small non-coding parts of the RNA family that regulate gene expression and may have an important role as biomarkers in evaluating treatment response. The dysregulation of miRNAs has been well studied in other diseases, especially in oncology, but their role in chronic skin conditions such as psoriasis is still not fully understood. This study aims to evaluate the levels of three miRNAs (miR-155, miR-210, and miR-205) in patients with psoriasis, treated either systemically or topically, compared to a control group, and to assess the possible relationship between miRNA levels and systemic therapy. Our findings show a constant dysregulation of miR-205 in patients with psoriasis, with significantly higher levels compared to the control group, which can be explained as conferring a protective effect to treated patients. Further studies are needed in order to fully understand the role of miRNAs in the physiopathology of psoriasis and even, potentially, to provide more targeted genetic therapies in the future.

Serum miRNA profiling identified miRNAs associated with disease severity in psoriasis

Psoriasis vulgaris is a chronic, autoimmune skin disease involving a complex interplay of epidermal keratinocytes, dermal fibroblast and infiltrating immune cells. Differential expressions of miRNAs are observed in psoriasis and the deregulated miRNAs are sometimes associated with disease severity. This study aims to identify miRNAs altered in the serum of psoriasis patients that are associated with the Psoriasis Area and Severity Index (PASI). In order to assess miRNA levels in the serum of psoriasis patients, we selected 24 differentially expressed miRNAs in the psoriatic skin are possibly derived from the skin and immune cells, as well as five miRNAs that are enriched in other tissues. We identified 16 miRNAs that exhibited significantly (p < 0.05) altered levels in the serum of psoriasis patients compared to healthy individuals. Among these, 13 miRNAs showed similar expression pattern in the serum of psoriasis patients as also observed in the psoriatic skin tissues. Ten miRNAs showed an accuracy of greater than 75% in classifying the psoriasis patients from healthy individuals. Further analysis of differential miRNA levels between the low PASI group and the high PASI group identified three miRNAs (miR-147b, miR-3614-5p, and miR-125a-5p) with significantly altered levels between the low severity and the high severity psoriasis patients. Our systematic investigation of skin and immune cell-derived miRNAs in the serum of psoriasis patients revealed alteration in miRNA levels to be associated with disease severity, which may help in monitoring the disease progression and therapeutic response.

Transcriptomic profiling of TLR-7-mediated immune-challenge in zebrafish embryos in the presence and absence of glucocorticoid-induced immunosuppression

Although numerous studies imply a correlation between chemical contamination and an impaired immunocompetence of wildlife populations, the assessment of immunomodulatory modes of action is currently not covered in the regulatory requirements for the approval of new substances. This is not least due to the complexity of the immune system and a lack of standardised methods and validated biomarkers. To tackle this issue, in this study, the transcriptomic profiles of zebrafish embryos were analysed in response to the immunosuppressive compound clobetasol propionate, a synthetic glucocorticoid, and/or the immunostimulatory compound imiquimod (IMQ), a TLR-7 agonist. Using IMQ, known for its potential to induce psoriasis-like effects in mice and human, this study additionally aimed at evaluating the usability of the zebrafish embryo model as an alternative and 3R conform system for the IMQ-induced psoriasis mouse model. Our study substantiates the suitability of previously proposed genes as possible biomarkers for immunotoxicity, such as socs3, nfkbia, anxa1c, fkbp5 and irg1l. Likewise, however, our findings indicate that these genes may be less suitable to distinguish a suppressive from stimulating fashion of action. In contrast, based on a differential regulation in opposite direction in response to both compounds, krt17, rtn4a, and1, smhyc1 and gmpr were identified as potential novel biomarkers with said power to differentiate. Observed IMQ-induced alterations in the expression of genes previously associated with the pathogenesis of psoriasis such as krt17, nfkbia, parp1, pparg, nfil3-6, per2, stat4, klf2, rtn4a, anxa1c and nr1d2 indicate the inducibility of psoriatic effects in the zebrafish embryo. Our work contributes to the establishment of an approach for a 3R-compliant investigation of immunotoxic mechanisms of action in aquatic vertebrates. The validated and newly identified biomarker candidates of specific immunotoxic effects can be used in future studies in the context of environmental hazard assessment of substances or also for human-relevant immunotoxicological questions.

The role of microRNA in psoriasis: A review

Psoriasis is a chronic immune-mediated inflammatory skin disease that involves a complex interplay between infiltrated immune cells and keratinocytes. Great progress has been made in the research on the molecular mechanism of coding and non-coding genes, which has helped in clinical treatment. However, our understanding of this complex disease is far from clear. MicroRNAs (miRNAs) are small non-coding RNA molecules that are involved in post-transcriptional regulation, characterised by their role in mediating gene silencing. Recent studies on miRNAs have revealed their important role in the pathogenesis of psoriasis. We reviewed the current advances in the study of miRNAs in psoriasis; the existing research has found that dysregulated miRNAs in psoriasis notably affect keratinocyte proliferation and/or differentiation processes, as well as inflammation progress. In addition, miRNAs also influence the function of immune cells in psoriasis, including CD4+ T cells, dendritic cells, Langerhans cells and so on. In addition, we discuss possible miRNA-based therapy for psoriasis, such as the topical delivery of exogenous miRNAs, miRNA antagonists and miRNA mimics. Our review highlights the potential role of miRNAs in the pathogenesis of psoriasis, and we expect more research progress with miRNAs in the future, which will help us understand this complex skin disease more accurately.

miRNA-559 and MTDH as possible diagnostic markers of psoriasis: Role of PTEN/AKT/FOXO pathway in disease pathogenesis

Psoriasis is a persistent, inflammatory, autoimmune skin disorder which can be elicited by genetic and environmental factors. Several microRNAs (miRNAs) that are abnormally expressed in psoriasis have emerged as an interesting candidate in psoriasis pathogenesis. However, the expression profile and function of miRNA-559, and its direct target metadherin (MTDH), in psoriasis need to be further illuminated. This study intended to assess miRNA-559 and MTDH levels in skin and sera of psoriatic patients and to investigate their clinical significance in an attempt for developing novel distinct tools for early diagnosis of psoriasis. Moreover, this study aimed at exploring participation of miRNA-559 in regulating MTDH/PTEN/AKT pathway in psoriasis. Expression levels of miRNA-559, AKT, FOXO1 and PTEN were measured by real-time qRT-PCR, whereas MTDH and p27 levels were assessed by ELISA in lesional, non-lesional tissues and serum of 20 psoriatic patients and 20 matching controls. Correlation study was conducted between different parameters. The diagnostic performance of miRNA-559 and MTDH in psoriasis was estimated by receiver operating characteristic (ROC) curve analysis. Expression of miRNA-559 in psoriatic patients was significantly downregulated in both lesional tissues and serum as compared to controls. Conversely, MTDH protein level showed significant increase in both tissues and serum of psoriatic patients and was inversely correlated with miRNA-559 level. Meanwhile, levels of PTEN, AKT and FOXO1 were dramatically changed in psoriatic patients compared to controls. Furthermore, serum miRNA-559 and MTDH displayed comparable diagnostic accuracy in discriminating psoriatic patients from controls. Yet, miRNA-559 demonstrated superior diagnostic performance than MTDH in psoriasis diagnosis. Together, the current findings provide the first suggestion of a new mechanism by which downregulation of miRNA-559 might induce proliferation in psoriasis through modulating PTEN/AKT/FOXO1 pathway by positive regulation of MTDH. Thus, miRNA-559 and MTDH might be proposed as promising diagnostic biomarkers of psoriasis.

Expression Signature of Immune-Related MicroRNAs in Autoimmune Skin Disease: Psoriasis and Vitiligo Insights

BACKGROUND

Psoriasis and vitiligo are both chronic, skin-specific diseases classified as autoimmune diseases due to the involvement of several biochemical pathways in their pathogenesis, similar to those altered in other autoimmune diseases. The role of miRNAs in regulating skin autoimmune function has yet to be fully characterized.

AIM

The aim of this study was to assess the expression profile of a panel of 11 circulating immune-related miRNAs in patients with autoimmune skin diseases, specifically psoriasis and vitiligo, and correlate their expression signature with the clinicopathological features of the diseases.

SUBJECTS AND METHODS

Relative gene expression quantification for 11 immune-related circulating miRNAs in plasma was done for 300 subjects-100 patients with psoriasis, 100 patients with vitiligo and 100 normal healthy volunteers-followed by different modalities of bioinformatics analysis for the results.

RESULTS

The expression levels of all the studied immune-related miRNAs were elevated in both autoimmune skin disorders, with much higher levels of expression in psoriasis than in vitiligo patients. There was a significant correlation between most of the studied miRNAs, suggesting shared target genes and/or pathways. Moreover, all the studied miRNAs showed significant results as biomarkers for autoimmune skin disease, with miRNA-145 being the best candidate. Regarding the clinicopathological data, miRNA-7, miRNA-9, miRNA-145, miRNA-148a, and miRNA-148b were positively correlated with age. All the miRNAs were inversely correlated with obesity and disease duration.

CONCLUSION

This study highlights the critical role of miRNAs in skin-specific autoimmune diseases that proved to be potential biomarkers for autoimmune skin disorders, warranting their exploration as therapeutic targets.

The miR-20a/miR-92b Profile Is Associated with Circulating γδ T-Cell Perturbations in Mild Psoriasis

Psoriasis vulgaris (PV) is an autoinflammatory dermatosis of unknown etiology. Current evidence suggests a pathogenic role of γδT cells, but the growing complexity of this population has made the offending subset difficult to pinpoint. The work on γδTCRint and γδTCRhi subsets, which express intermediate and high levels of γδTCR at their surface, respectively, is particularly scarce, leaving their inner workings in PV essentially unresolved. We have shown here that the γδTCRint/γδTCRhi cell composition and their transcriptom are related to the differential miRNA expression by performing a targeted miRNA and mRNA quantification (RT-qPCR) in multiplexed, flow-sorted γδ blood T cells from healthy controls (n = 14) and patients with PV (n = 13). A significant loss of miR-20a in bulk γδT cells (~fourfold decrease, PV vs. controls) largely mirrored increasing Vδ1-Vδ2- and γδintVδ1-Vδ2- cell densities in the bloodstream, culminating in a relative excess of γδintVδ1-Vδ2- cells for PV. Transcripts encoding DNA-binding factors (ZBTB16), cytokine receptors (IL18R1), and cell adhesion molecules (SELPLG) were depleted in the process, closely tracking miR-20a availability in bulk γδ T-cell RNA. Compared to controls, PV was also associated with enhanced miR-92b expression (~13-fold) in bulk γδT cells that lacked association with the γδT cell composition. The miR-29a and let-7c expressions remained unaltered in case-control comparisons. Overall, our data expand the current landscape of the peripheral γδT cell composition, underlining changes in its mRNA/miRNA transcriptional circuits that may inform PV pathogenesis.

Plasma extracellular vesicles microRNA-208b-3p and microRNA-143-3p as novel biomarkers for sudden cardiac death prediction in acute coronary syndrome

Acute coronary syndrome (ACS) occurs as a result of myocardial ischemia that can give rise to a variety of acute cardiovascular events, including arrhythmia, heart failure and sudden cardiac death (SCD). Currently, there are challenges and insufficient innovations regarding early diagnosis and therapeutic approaches within ACS patients experiencing SCD. Plasma extracellular vesicles (EVs) might serve as biomarkers of many diseases depending on the biological molecules of their cargo, such as miRNAs. This study aims to identify the plasma EVs containing miRNAs as novel biomarkers for the prediction of SCD in ACS patients. A total of 39 ACS patients experiencing SCD and 39 healthy control individuals (HC) were enrolled, among which 9 samples in each group were randomly selected as testing groups for miRNA sequencing in plasma EVs, and the remaining samples were assigned to the validation group. The top 10 significant expression miRNAs were verified by the real-time quantitative polymerase chain reaction. Upregulation of miR-208b-3p, miR-143-3p, miR-145-3p and miR-152-3p, and down-regulation of miR-183-5p were further validated in the validation group. Spearman's correlation analysis and the receiver operating characteristic (ROC) curve showed that both miR-208b-3p and miR-143-3p levels were positively correlated with myoglobin (MYO), and their predictive power for SCD was confirmed. In conclusion, our findings indicate that plasma EVs miR-208b-3p and miR-143-3p may serve as promising biomarkers in predicting SCD in patients with ACS, as well as postmortem forensic diagnosis of the cause of death due to ACS.

ITGA9 Inhibits Proliferation and Migration of Dermal Microvascular Endothelial Cells in Psoriasis

Background

Cell proliferation, migration, and angiogenesis are aberrant in psoriatic human dermal microvascular endothelial cells (HDMECs), resulting in abnormal endothelial function and microvascular dilation in psoriasis.

Objective

To explore the role of Integrin subunit alpha 9 (ITGA9) in proliferation and migration of dermal microvascular endothelial cells.

Methods

HDMECs were isolated from the skin of 6 psoriatic patients and 6 healthy controls. Expression levels of ITGA9 mRNA and protein were assessed with qRT-PCR and Western blot, respectively, while miqRT-PCR was used to determine expression levels of miR-146a-3p. Cell proliferation and migration were assessed in human microvascular endothelial cell line (HMEC-1), following overexpression of either ITGA9 or miR-146a-3p, or co-transfection with miR-146a-3p-mimic and pLVX - ITGA9. Cell viability was detected by Cell Counting Kit-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) cell proliferation assay. Cell apoptosis was assessed, using annexin V-FITC/PI apoptosis detection kit, while cell migration was detected by wound healing and transwell assay.

Results

Expression levels of ITGA9 were significantly decreased in psoriatic HDMECs compared to normal controls. Moreover, expression levels of miR-146a-3p were higher in psoriatic HDMECs than in normal controls. Overexpression of miR-146a-3p lowered expression levels of ITGA9, accompanied by increased proliferation and migration of HMEC-1 in vitro. In contrast, overexpression of ITGA9 inhibited proliferation and migration of HMEC-1, while increasing expression levels of cdc42, ki67, focal adhesion kinase (FAK), c-Src tyrosine kinase (Src), RAC1 and RhoA.

Conclusion

ITGA9 can repress the proliferation and migration of HMEC-1, suggesting utility of ITGA9 as a potential therapeutic intervention for psoriasis.

Circulating microRNA203 and its target genes' role in psoriasis pathogenesis

Numerous microRNAs (miRNAs) have been found to have an aberrant expression in the peripheral blood or psoriasis patients' lesions. Psoriasis was shown to have the abnormal expression of microRNA-203 (miR-203). It is a skin-specific signal that governs cellular proliferation in a protein kinase C-dependent manner and is mostly generated by keratinocytes. This work evaluated the expression levels of the circulating miR-203 target genes SOCS3, SOCS6, TP63, TNF-, IL8, and IL24 in psoriasis patients. Using a relative quantitation PCR technique, we determined the expression levels of miR-203 and its target genes (SOCS3, SOCS6, TP63, TNF-, IL8, and IL24) in the plasma of 120 psoriatic patients and matched healthy controls. The disease characteristics of the patients were then correlated with the expression results. We also conducted numerous enrichment analyses for the diseases, functions, and pathways connected to the under-researched biomarkers. Compared to healthy controls, psoriatic patients had significantly increased levels of miR-203 expression; 7.1 (4.4–9.9). In contrast, psoriatic patients had significantly lower expression of all the examined genes compared to healthy controls. Regarding all the study biomarkers, the receiver operating characteristic (ROC) curve analysis demonstrated significant sensitivity and specificity for differentiating between psoriatic patients and healthy controls. According to the results of the disease matching score generated by miR-203 and its target genes, psoriasis was ranked first with a score of 4.45. The third-place finisher with a value of 3.98, it also demonstrated that miR-203 and its target genes are connected to various skin disorders. Our results show that miR-203 contributes to psoriasis pathogenesis not only locally in skin lesions but also in circulation, indicating that it may contribute to the systemic symptoms of the illness. MiR-203 overexpression in psoriasis suggests that miR-203 may be involved in an anti-inflammatory response because it targets both SOCS gene family members and pro-inflammatory cytokines.

Contribution of the Environment, Epigenetic Mechanisms and Non-Coding RNAs in Psoriasis

Despite the increasing research and clinical interest in the predisposition of psoriasis, a chronic inflammatory skin disease, the multitude of genetic and environmental factors involved in its pathogenesis remain unclear. This complexity is further exacerbated by the several cell types that are implicated in Psoriasis’s progression, including keratinocytes, melanocytes and various immune cell types. The observed interactions between the genetic substrate and the environment lead to epigenetic alterations that directly or indirectly affect gene expression. Changes in DNA methylation and histone modifications that alter DNA-binding site accessibility, as well as non-coding RNAs implicated in the post-transcriptional regulation, are mechanisms of gene transcriptional activity modification and therefore affect the pathways involved in the pathogenesis of Psoriasis. In this review, we summarize the research conducted on the environmental factors contributing to the disease onset, epigenetic modifications and non-coding RNAs exhibiting deregulation in Psoriasis, and we further categorize them based on the under-study cell types. We also assess the recent literature considering therapeutic applications targeting molecules that compromise the epigenome, as a way to suppress the inflammatory cutaneous cascade.

Epigenetic Mechanisms of Epidermal Differentiation

Keratinocyte differentiation is an essential process for epidermal stratification and stratum corneum formation. Keratinocytes proliferate in the basal layer of the epidermis and start their differentiation by changing their functional or phenotypical type; this process is regulated via induction or repression of epidermal differentiation complex (EDC) genes that play a pivotal role in epidermal development. Epidermal development and the keratinocyte differentiation program are orchestrated by several transcription factors, signaling pathways, and epigenetic regulators. The latter exhibits both activating and repressive effects on chromatin in keratinocytes via the ATP-dependent chromatin remodelers, histone demethylases, and genome organizers that promote terminal keratinocyte differentiation, and the DNA methyltransferases, histone deacetylases, and Polycomb components that stimulate proliferation of progenitor cells and inhibit premature activation of terminal differentiation-associated genes. In addition, microRNAs are involved in different processes between proliferation and differentiation during the program of epidermal development. Here, we bring together current knowledge of the mechanisms controlling gene expression during keratinocyte differentiation. An awareness of epigenetic mechanisms and their alterations in health and disease will help to bridge the gap between our current knowledge and potential applications for epigenetic regulators in clinical practice to pave the way for promising target therapies.

LncRNA XIST engages in psoriasis via sponging miR-338-5p to regulate keratinocyte proliferation and inflammation

INTRODUCTION

Psoriasis is an immune-mediated polygenic inflammatory skin disease, keratinocyte proliferation is an important mechanism. The study investigated the role and regulatory relationship between lncRNA XIST and miR-338-5p in psoriatic patients and cell models.

METHODS

Serum samples were collected from 55 psoriasis patients. HaCaT was recruited for the cell experiments, and induced by M5 cytokines to mimic psoriasis in vitro. XIST and miR-338-5p levels were detected via qRT-PCR. Cell viability under different treatments was evaluated using CCK-8. ELISA was applied to measure the concentration of inflammatory cytokines. The regulatory relationship was confirmed using luciferase reporter gene assay.

RESULTS

Serum XIST was elevated in patients with psoriasis, and can distinguish the psoriasis patients from healthy controls according to the ROC curve. High level of XIST was positively correlated with with PASI score and serum TNF-α, IL-17A and IL-22 concentrations in psoriasis patients. XIST silencing suppressed M5-induced keratinocyte proliferation and restrained the discharge of inflammatory cytokines (TNF-α, IL-17A, IL-22) and chemokines (CXCL1, CXCL8, CCL20). XIST can sponge miR-338-5p, and miR-338-5p downregulation abolished the inhibitory effect of XIST silencing on cell proliferation and inflammation. miR-338-5p was at high expression in the clinical serum samples from psoriasis patients. The target relationship between miR-338-5p and IL-6 was proved.

CONCLUSION

LncRNA XIST is highly expressed in the serum of patients with psoriasis, and was positively correlated with disease severity and inflammation. XIST may regulate keratinocyte proliferation and inflammation via regulating miR-338-5p/IL-6 axis.

MicroRNA profiling of psoriatic skin identifies 11 miRNAs associated with disease severity

MicroRNAs (miRNAs) are small non-coding RNAs that have emerged as central regulators of gene expression and powerful biomarkers of disease. Much is yet unknown about their role in psoriasis pathology. To globally characterize the miRNAome of psoriatic skin, skin biopsies were collected from psoriatic cases (n = 75) and non-psoriatic controls (n = 46) and RNA sequenced. Count data were meta-analysed with a previously published dataset (cases, n = 24, controls, n = 20), increasing the number of psoriatic cases fourfold from previously published studies. Differential gene expression analyses were performed comparing lesional psoriatic (PP), non-lesional psoriatic (PN) and control (NN) skin. Further, functional enrichment and cell-specific analyses were performed. Across all contrasts, we identified 439 significantly differentially expressed miRNAs (DEMs), of which 85 were novel for psoriasis and 11 were related to disease severity. Meta-analyses identified 20 DEMs between PN and NN, suggesting an inherent change in the constitution of all skin in psoriasis. By integrating the miRNA transcriptome with mRNA target interactions, we identified several functionally enriched terms, including "thyroid hormone signalling," "insulin resistance" and various infectious diseases. Cell-specific expression analyses revealed that the upregulated DEMs were enriched in epithelial and immune cells. This study provides the most comprehensive overview of the miRNAome in psoriatic skin to date and identifies a miRNA signature related to psoriasis severity. Our results may represent molecular links between psoriasis and related comorbidities and have outlined potential directions for future functional studies to identify biomarkers and treatment targets.

RETRACTED: MiR-15a-5p targets FOSL1 to inhibit proliferation and promote apoptosis of keratinocytes via MAPK/ERK pathway

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. According to the authors, concerns with the experimental conduct presented in the paper have been identified, in addition to the grounds that that ethical approval was not sought or confirmed for the research undertaken. After a review, the Editor has confirmed approval that this paper should be retracted as it presents a violation of the Journal’s publishing policies and publishing ethics standards.

miR-21-3p/IL-22 Axes Are Major Drivers of Psoriasis Pathogenesis by Modulating Keratinocytes Proliferation-Survival Balance and Inflammatory Response

Psoriasis is a chronic inflammatory skin disease that is mediated by complex crosstalk between immune cells and keratinocytes (KCs). Emerging studies have showed a specific psoriatic microRNAs signature, in which miR-21 is one of the most upregulated and dynamic miRNAs. In this study, we focused our investigations on the passenger miR-21-3p strand, which is poorly studied in skin and in psoriasis pathogenesis. Here, we showed the upregulation of miR-21-3p in an IMQ-induced psoriasiform mouse model. This upregulation was correlated with IL-22 expression and functionality, both in vitro and in vivo, and it occurred via STAT3 and NF-κB signaling. We identified a network of differentially expressed genes involved in abnormal proliferation control and immune regulatory genes implicated in the molecular pathogenesis of psoriasis in response to miR-21-3p overexpression in KCs. These results were confirmed by functional assays that validated the proliferative potential of miR-21-3p. All these findings highlight the importance of miR-21-3p, an underestimated miRNA, in psoriasis and provide novel molecular targets for therapeutic purposes.

CircRAB3B suppresses proliferation, motility, cell cycle progression and promotes the apoptosis of IL-22-induced keratinocytes depending on the regulation of miR-1228-3p/PTEN axis in psoriasis

INTRODUCTION

Psoriasis is an immune-related chronic skin disease, and interleukin-22 (IL-22) is involved in psoriasis pathogenesis through promoting proliferation and migration abilities of keratinocytes. Here, we analysed the role of circular RNA (circRNA) RAB3B, member RAS oncogene family (circRAB3B) in regulating the phenotypes of IL-22-induced HaCaT cells.

METHODS

RT-qPCR was implemented to assess RNA abundance. Western blot assay was adopted to assess protein abundance. Cell proliferation capacity was examined by cell counting kit-8 (CCK8) assay and 5-ethynyl-2'-deoxyuridine (Edu) assay. Cell motility was assessed by transwell assays and wound healing assay. Flow cytometric analysis was utilized to evaluate cell cycle progression and apoptosis. The intermolecular binding relations were tested via dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. CircRAB3B expression was reduced in psoriatic cutaneous specimens and IL-22-treated HaCaT cells.

RESULTS

CircRAB3B overexpression hampered the proliferation, motility, and cell cycle progression and elevated the apoptotic rate of IL-22-treated HaCaT cells, and circRAB3B silencing exhibited opposite effects in IL-22-induced HaCaT cells. CircRAB3B acted as microRNA-1228-3p (miR-1228-3p) sponge in HaCaT cells, and miR-1228-3p overexpression largely overturned circRAB3B overexpression-induced effects in HaCaT cells. MiR-1228-3p interacted with phosphatase and tensin homolog (PTEN), and circRAB3B sponged miR-1228-3p to induce PTEN level. MiR-1228-3p accumulation-mediated effects were partly alleviated by PTEN overexpression in HaCaT cells upon IL-22 treatment.

CONCLUSIONS

CircRAB3B suppressed psoriasis progression partly through down-regulating miR-1228-3p and up-regulating PTEN.

Expression of microRNA-21 and TIMP-3 in paradoxical psoriasiform reactions during treatment with antitumor necrosis factor agents

BACKGROUND

Expression of microRNA-21 (miR-21) is increased in psoriasis, leading to reduced levels of epidermal tissue inhibitor of matrix metalloproteinase 3 (TIMP-3), a highly potent inhibitor of the tumor necrosis factor alpha (TNFα) sheddase TACE (TNFα-converting enzyme)/ADAM17. We described the profile of miR-21 and TIMP-3 in paradoxical psoriasiform reactions induced by anti-TNFα drugs and in a control group to elucidate the pathogenesis of this reactions.

METHODS

We performed an analytic, cross-sectional, prospective, experimental case-control study. We compared our findings with those of non-induced psoriasis.

RESULTS

We included 15 patients with a change of morphology (plaque to guttate psoriasis) and 10 patients with induced psoriasis (six palmoplantar pustulosis and four plaque psoriasis). Consecutive patients with different subtypes of non-induced, non-systemically treated psoriasis were included as a control group. We found that most cases with guttate psoriasis and with induced plaque psoriasis cases showed high expression of TIMP-3 expression and decreased or poorly increased levels of miR-21. The expression pattern was not homogeneous in the cases of induced palmoplantar pustulosis. These profiles differ from those of non-induced psoriasis.

CONCLUSION

We conclude that various pro-inflammatory cytokine profiles are involved in the pathogenesis of paradoxical psoriasiform reactions and non-induced psoriasis.

H3K27Ac modification and gene expression in psoriasis

BACKGROUND

Numerous alterations in gene expression have been described in psoriatic lesions compared to uninvolved or healthy skin. However, the mechanisms which induce this altered expression remain unclear. Epigenetic modifications play a key role in regulating genes' expression. Only three studies compared the whole-genome DNA methylation of psoriasis versus healthy skin. The present is the first study of genome-wide comparison of histone modifications between psoriatic to healthy skins.

OBJECTIVE

Our objective was to explore the pattern of H3K27Ac modifications in psoriatic lesions compared to uninvolved psoriatic and healthy skin, in order to identify new genes involved in the pathogenesis of psoriasis.

METHOD

Using ChIP-seq with anti H3K27Ac we compared the acetylation of lysine 27 on histone 3 (H3K27Ac) modification between psoriatic to healthy skins, combined with mRNA array.

RESULTS

We found a differential H3K27Ac pattern between psoriatic compared to uninvolved or healthy skins. We found that many of the overexpressed and H3K27Ac enriched genes in psoriasis, harbor a putative GRHL transcription factor-binding site.

CONCLUSIONS

In the most overexpressed genes in psoriasis, there is an enrichment of H3K27Ac. However, the loss of H3K27 acetylation modification does not correlate with decreased gene expression. GRHL appears to play an important role in the pathogenesis of psoriasis and therefore, might be a new target for psoriasis therapeutics.

The Psoriatic Nonlesional Skin: A Battlefield between Susceptibility and Protective Factors

In the last two decades, large-scale gene-expression studies on psoriatic skin samples revealed that even though nonlesional skin is macroscopically identical to healthy skin, it harbors several molecular differences. Originally, these molecular differences were thought to represent susceptibility factors for plaque formation. However, we review in this paper the several factors of immune regulation and structural alteration that are specific for the nonlesional skin and serve as protective factors by counteracting plaque formation and contributing to the maintenance of the nonlesional phenotype.

MiR-141-3p and miR-200a-3p are involved in Th17 cell differentiation by negatively regulating RARB expression

Among T helper (Th) lineages differentiated from naïve CD4⁺ T cells, interleukin (IL)-17-producing Th17 cells are highly correlated with the pathogenesis of autoimmune disorders. This study aimed to clarify the involvement of miR-141-3p and miR-200a-3p in Th17 cell differentiation as well as explore their potential target genes involved. For this purpose, human naïve CD4⁺ T cells were cultured under Th17 cell polarizing condition. The differentiation process was confirmed through measurement of IL-17 secretion using the ELISA method and assessment of Th17 cell-defining genes expression during the differentiation period. MiR-141-3p and miR-200a-3p downstream genes were identified via consensus and integration in silico approach and their expression pattern and alterations were evaluated by quantitative real-time PCR. Finally, direct interaction between both microRNAs (miRNAs) and their common predicted target sequences was approved by dual-luciferase reporter assay. Highly increased IL-17 secretion and Th17 lineage-specific genes expression confirmed Th17 cell differentiation. Our results have demonstrated that miR-141-3p and miR-200a-3p are Th17 cell-associated miRNAs and their expression level is upregulated significantly during Th17 cell induction. We have also found that retinoic acid receptor beta (RARB) gene, whose product has been reported as a negative regulator of Th17 cell generation, is a direct target of both miRNAs and its downregulation can affect the transcriptional level of JAK/STAT pathway genes. Overall, our results have identified two novel Th17 lineage-associated miRNAs and have provided evidence for the RARB-dependent mechanism of miR-141-3p and miR-200a-3p-induced Th17 cell differentiation and hence Th17-mediated autoimmunity.

Parkinson mice show functional and molecular changes in the gut long before motoric disease onset

BACKGROUND

There is increasing evidence that Parkinson's disease (PD) might start in the gut, thus involving and compromising also the enteric nervous system (ENS). At the clinical onset of the disease the majority of dopaminergic neurons in the midbrain is already destroyed, so that the lack of early biomarkers for the disease represents a major challenge for developing timely treatment interventions. Here, we use a transgenic A30P-α-synuclein-overexpressing PD mouse model to identify appropriate candidate markers in the gut before hallmark symptoms begin to manifest.

METHODS

Based on a gait analysis and striatal dopamine levels, we defined 2-month-old A30P mice as pre-symptomatic (psA30P), since they are not showing any motoric impairments of the skeletal neuromuscular system and no reduced dopamine levels, but an intestinal α-synuclein pathology. Mice at this particular age were further used to analyze functional and molecular alterations in both, the gastrointestinal tract and the ENS, to identify early pathological changes. We examined the gastrointestinal motility, the molecular composition of the ENS, as well as the expression of regulating miRNAs. Moreover, we applied A30P-α-synuclein challenges in vitro to simulate PD in the ENS.

RESULTS

A retarded gut motility and early molecular dysregulations were found in the myenteric plexus of psA30P mice. We found that i.e. neurofilament light chain, vesicle-associated membrane protein 2 and calbindin 2, together with the miRNAs that regulate them, are significantly altered in the psA30P, thus representing potential biomarkers for early PD. Many of the dysregulated miRNAs found in the psA30P mice are reported to be changed in PD patients as well, either in blood, cerebrospinal fluid or brain tissue. Interestingly, the in vitro approaches delivered similar changes in the ENS cultures as seen in the transgenic animals, thus confirming the data from the mouse model.

CONCLUSIONS

These findings provide an interesting and novel approach for the identification of appropriate biomarkers in men.

Upregulation of the miRNA-155, miRNA-210, and miRNA-20b in psoriasis patients and their relation to IL-17

Psoriasis is an immune-mediated disease, with genetic background and triggering environmental factors; however, several gaps are still present in understanding the intertwined relationship between these elements. Epigenetic mechanisms, including microRNAs (miRNAs), play an important role in the pathogenesis of psoriasis. The relationship between interleukin (IL)-17, a key cytokine in psoriasis, and these epigenetic mechanisms still needs to be elucidated. This study aimed at assessing the expression of miRNA-155, miRNA-210, and miRNA-20b in skin and sera of psoriasis patients in relation to IL-17 levels. For 20 psoriasis patients and 20 matching controls, the expression of miRNA-155, miRNA-210, and miRNA-20b was assessed using real-time polymerase chain reaction (RT-PCR), whereas IL-17/IL-17A levels were measured using quantitative enzyme-linked immunosorbent assay (ELISA) technique. MiRNA-155 expression was significantly higher in lesional skin compared to controls (P = 0.001). MiRNA-210 expression was significantly higher in both, lesional skin (P = 0.010) and sera of patients (P = 0.001) in comparison with controls. A statistically significant positive correlation was found between serum miRNA-210 expression and serum levels of IL-17/IL-17A (P = 0.010, rs = 0.562). MiRNA-20b lesional and non-lesional expression was significantly higher than controls (P < 0.001; P = 0.018). In conclusion, the expression of miRNA-155, miRNA-210, and miRNA-20b is exaggerated in psoriasis and they may be involved in disease pathogenesis. A possible relationship between miRNA-210 and IL-17 may be suggested; however, further studies are still needed to verify this relation.

Epigenetics in Non-tumor Immune-Mediated Skin Diseases

Epigenetics is the study of the mechanisms that regulate gene expression without modifying DNA sequences. Knowledge of and evidence about how epigenetics plays a causative role in the pathogenesis of many skin diseases is increasing. Since the epigenetic changes present in tumor diseases have been thoroughly reviewed, we believe that knowledge of the new epigenetic findings in non-tumor immune-mediated dermatological diseases should be of interest to the general dermatologist. Hence, the purpose of this review is to summarize the recent literature on epigenetics in most non-tumor dermatological pathologies, focusing on psoriasis. Hyper- and hypomethylation of DNA methyltransferases and methyl-DNA binding domain proteins are the most common and studied methylation mechanisms. The acetylation and methylation of histones H3 and H4 are the most frequent and well-characterized histone modifications and may be associated with disease severity parameters and serve as therapeutic response markers. Many specific microRNAs dysregulated in non-tumor dermatological disease have been reviewed. Deepening the study of how epigenetic mechanisms influence non-tumor immune-mediated dermatological diseases might help us better understand the role of interactions between the environment and the genome in the physiopathogenesis of these diseases.

miRNAs Flowing Up and Down: The Concerto of Psoriasis

Psoriasis is a chronic immune-mediated skin disease, whose hallmarks include keratinocyte hyperproliferation and CD4⁺ T cell subsets imbalance. Dysregulated microRNAs (miRNAs) identified in psoriasis have been shown to affect keratinocyte and T cell functions, with studies on the molecular mechanisms and intrinsic relationships of the miRNAs on the way. Here, we focus on the dysregulated miRNAs that contribute to the two hallmarks of psoriasis with the miRNA target genes confirmed. We review a network, in which, upregulated miR-31/miR-203/miR-155/miR-21 and downregulated miR-99a/miR-125b facilitate the excessive proliferation and abnormal differentiation of psoriatic keratinocytes; upregulated miR-210 and downregulated miR-138 work in concert to distort CD4⁺ T cell subsets balance in psoriasis. The miRNAs exert their functions through regulating key psoriasis-associated transcription factors including NF-κB and STAT3. Whether flowing up or down, these miRNAs collaborate to promote the development and maintenance of psoriasis.

Epigenetic Regulation of Epidermal Differentiation

The epidermis is the outer part of the skin that protects the organism from dehydration and shields from external insults. Epidermal cells, called keratinocytes, undergo a series of morphological and metabolic changes that allow them to establish the biochemical and structural elements of an effective epidermal barrier. This process, known as epidermal differentiation, is critical for the maintenance of the epidermis under physiological conditions and also under stress or in various skin pathologies. Epidermal differentiation relies on a highly coordinated program of gene expression. Epigenetic mechanisms, which commonly include DNA methylation, covalent histone modifications, and microRNA (miRNA) activity, modulate various stages of gene expression by altering chromatin accessibility and mRNA stability. Their involvement in epidermal differentiation is a matter of intensive studies, and the results obtained thus far show a complex network of epigenetic factors, acting together with transcriptional regulators, to maintain epidermal homeostasis and counteract adverse effects of environmental stressors.

The Roles of Matrix Metalloproteinases and Their Inhibitors in Human Diseases

Matrix metalloproteinases (MMPs) are a family of zinc-dependent extracellular matrix (ECM) remodeling endopeptidases that have the capacity to degrade almost every component of the ECM. The degradation of the ECM is of great importance, since it is related to embryonic development and angiogenesis. It is also involved in cell repair and the remodeling of tissues. When the expression of MMPs is altered, it can generate the abnormal degradation of the ECM. This is the initial cause of the development of chronic degenerative diseases and vascular complications generated by diabetes. In addition, this process has an association with neurodegeneration and cancer progression. Within the ECM, the tissue inhibitors of MMPs (TIMPs) inhibit the proteolytic activity of MMPs. TIMPs are important regulators of ECM turnover, tissue remodeling, and cellular behavior. Therefore, TIMPs (similar to MMPs) modulate angiogenesis, cell proliferation, and apoptosis. An interruption in the balance between MMPs and TIMPs has been implicated in the pathophysiology and progression of several diseases. This review focuses on the participation of both MMPs (e.g., MMP-2 and MMP-9) and TIMPs (e.g., TIMP-1 and TIMP-3) in physiological processes and on how their abnormal regulation is associated with human diseases. The inclusion of current strategies and mechanisms of MMP inhibition in the development of new therapies targeting MMPs was also considered.

MicroRNAs in Several Cutaneous Autoimmune Diseases: Psoriasis, Cutaneous Lupus Erythematosus and Atopic Dermatitis

MicroRNAs (miRNAs) are endogenous small non-coding RNA molecules that regulate the gene expression at a post-transcriptional level and participate in maintaining the correct cell homeostasis and functioning. Different specific profiles have been identified in lesional skin from autoimmune cutaneous diseases, and their deregulation cause aberrant control of biological pathways, contributing to pathogenic conditions. Detailed knowledge of microRNA-affected pathways is of crucial importance for understating their role in skin autoimmune diseases. They may be promising therapeutic targets with novel clinical implications. They are not only present in skin tissue, but they have also been found in other biological fluids, such as serum, plasma and urine from patients, and therefore, they are potential biomarkers for the diagnosis, prognosis and response to treatment. In this review, we discuss the current understanding of the role of described miRNAs in several cutaneous autoimmune diseases: psoriasis (Ps, 33 miRNAs), cutaneous lupus erythematosus (CLE, 2 miRNAs) and atopic dermatitis (AD, 8 miRNAs). We highlight their role as crucial elements implicated in disease pathogenesis and their applicability as biomarkers and as a novel therapeutic approach in the management of skin inflammatory diseases.

Insightful exploring of microRNAs in psoriasis and its targeted topical delivery

Psoriasis is a common immune-mediated inflammatory skin disease. It includes multifaceted interaction between the immune system and the keratinocytes. Recent studies depicted the role of microRNAs (miRNAs) in hyperproliferation of keratinocytes and inflammatory cytokine production, which serve as biomarkers for diagnosis, monitoring treatment response, and prognosis. miRNAs are small nucleotide sequenced noncoding RNAs. Deregulation of miRNAs was found to be the most common factor in the studies pertaining to psoriasis. Hence, miRNA-based targeting for psoriasis treatment became the primary field of current research. miRNA due to its spatial and chemical properties offer different challenges in the process of its delivery. The topical delivery of different siRNAs and genes has paved a way to similar delivery of miRNA. The topical delivery of miRNAs to the skin can bring a revolutionary change in the field of psoriasis treatment.

A comprehensive review on miR-146a molecular mechanisms in a wide spectrum of immune and non-immune inflammatory diseases

MicroRNAs (miRNAs) are single-strand endogenous and non-coding RNA molecules with a length of about 22 nucleotides, which regulate genes expression, through modulating the translation and stability of their target mRNAs. miR-146a is one of the most studied miRNAs, due to its central role in immune system homeostasis and control of the innate and acquired immune responses. Accordingly, abnormal expression or function of miR-146a results in the incidence and progression of immune and non-immune inflammatory diseases. Its deregulated expression pattern and inefficient function have been reported in a wide spectrum of these illnesses. Based on the existing evidence, this miRNA qualifies as an ideal biomarker for diagnosis, prognosis, and activity evaluation of immune and non-immune inflammatory disorders. Moreover, much attention has recently been paid to therapeutic potential of miR-146a and several researchers have assessed the effects of different drugs on expression and function of this miRNA at diverse experimental, animal, besides human levels, reporting motivating results in the treatment of the diseases. Here, in this comprehensive review, we provide an overview of miR-146a role in the pathogenesis and progression of several immune and non-immune inflammatory diseases such as Rheumatoid arthritis, Systemic lupus erythematosus, Inflammatory bowel disease, Multiple sclerosis, Psoriasis, Graves' disease, Atherosclerosis, Hepatitis, Chronic obstructive pulmonary disease, etc., discuss about its eligibility for being a desirable biomarker for these disorders, and also highlight its therapeutic potential. Understanding these mechanisms underlies the selecting and designing the proper therapeutic targets and medications, which eventually facilitate the treatment process.

Pathogenesis of psoriasis in the "omic" era. Part II. Genetic, genomic and epigenetic changes in psoriasis

Psoriasis is a multifactorial disease in which genetic, environmental and epigenetic factors regulating gene expression play a key role. In the “genomic era”, genome-wide association studies together with target genotyping platforms performed in different ethnic populations have found more than 50 genetic susceptible markers associated with the risk of psoriasis which have been identified so far. Up till now, the strongest association with the risk of the disease has been proved for HLA-C*06 gene. The majority of other psoriasis risk SNPs are situated near the genes encoding molecules involved in adaptive and innate immunity, and skin barrier function. Many contemporary studies indicate that the epigenetic changes: histone modification, promoter methylations, long non-coding and micro-RNA hyperexpression are considered as factors contributing to psoriasis pathogenesis as they regulate abnormal keratinocyte differentiation and proliferation, aberrant keratinocytes – inflammatory cells communication, neoangiogenesis and chronic inflammation. The circulating miRNAs detected in the blood may become specific markers in the diagnosis, prognosis and response to the treatment of the disease. The inhibition of expression in selected miRNAs may be a new promising therapy option for patients with 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.

Autophagy plays a positive role in induction of epidermal proliferation

Autophagy is a multistage catabolic process that mediates stress responses. However, the role of autophagy in epidermal proliferation, particularly under conditions when the epidermis becomes "activated" (hyperproliferative), remains unclear. We have shown that inhibition of Beclin 1, a key activator in the initiation phase of autophagy, attenuates imiquimod (IMQ)-induced epidermal hyperplasia in adult mice as well as naturally occurring hyperproliferation in neonatal mouse epidermis. Inhibition of Beclin 1 did not change the levels of several key inflammatory molecules or the numbers of immune cells in lesional skins. This indicates that autophagy does not affect inflammatory regulators in IMQ-treated mouse skin. Bioinformatic analysis combined with gene expression quantitative assays, revealed that a deficiency in autophagy decreases the expression of PDZ Binding Kinase (PBK), a regulator of the cell cycle, in mouse epidermis and human epidermal keratinocytes (HEKs). Interestingly, the decrease in PBK results in inhibition of proliferation in HEKs and such reduced proliferation can be rescued by activation of p38, the downstream signaling of PBK. Collectively, autophagy plays a positive role in epidermal proliferation, which is in part via regulating PBK expression.

miR-203 promotes HaCaT cell overproliferation through targeting LXR-α and PPAR-γ

Psoriasis is an immune-mediated chronic inflammatory skin disease. Keratinocyte hyperproliferation has been regarded as a significant event in psoriasis pathogenesis. Considering the vital role of miRNA-mediated mRNA repression in psoriasis pathogenesis, in the present study, we attempted to investigate the mechanism of keratinocyte overproliferation from the point of miRNA-mRNA regulation. Both online microarray expression profiles and experimental results indicated that the expression of LXR-α and PPAR-γ was downregulated in psoriasis lesion skin. LXR-α or PPAR-γ overexpression alone was sufficient to inhibit keratinocyte proliferation, decrease KRT5 and KRT14 protein levels and increase KRT1 and KRT10 protein levels. miR-203 negatively regulated LXR-α and PPAR-γ expression through direct targeting. miR-203 inhibition exerted the opposite effects to LXR-α or PPAR-γ overexpression on HaCaT cells. More importantly, LXR-α or PPAR-γ overexpression could markedly remarkably attenuate the effects of miR-203 overexpression in keratinocytes, indicating that miR-203 promotes keratinocyte proliferation by targeting LXR-α and PPAR-γ. In conclusion, the miR-203-LXR-α/PPAR-γ axis modulates the proliferation of keratinocytes and might be a novel target for psoriasis treatment, which needs further in vivo investigation.

miR-205-5p inhibits psoriasis-associated proliferation and angiogenesis: Wnt/β-catenin and mitogen-activated protein kinase signaling pathway are involved

Psoriasis is a chronic inflammatory skin disease, and the mechanism remains unknown. The present study found that the level of miR-205-5p was downregulated in psoriatic skin tissues. miR-205-5p inhibited proliferation in HaCaT cells. miR-205-5p impaired proliferation, migration and tube formation in human umbilical vein endothelial cells. Angiopoietin (Ang)-2, vascular endothelial growth factor (VEGFA) and bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI) were confirmed as the targets of miR-205-5p. Moreover, miR-205-5p suppressed the phosphorylation of p38 and extracellular regulated protein kinase, and inhibited expression level of β-catenin. In vivo, miR-205-5p significantly alleviated imiquimod (IMQ)-induced psoriasis in mice, and deactivated mitogen-activated protein kinase (MAPK) and Wnt/β-catenin pathways. In summary, we demonstrated that miR-205-5p alleviated IMQ-induced psoriasis in mice by restraining epidermal hyperproliferation and excessive neovascularization. miR-205-5p may play its roles by targeting Ang-2, VEGFA and BAMBI, and deactivating the Wnt/β-catenin and MAPK signaling pathways. These findings may provide a potential therapeutic target for clinical treatment of psoriasis.

The miR-155/GATA3/IL37 axis modulates the production of proinflammatory cytokines upon TNF-α stimulation to affect psoriasis development

Psoriasis is a recrudescent chronic immune-mediated inflammatory dermatosis; the production and release of proinflammatory cytokines/chemokines such as TNF-α has been regarded as critical issues during psoriasis pathogenesis. Based on online microarray profiles, the expression of the transcription factor GATA3 was downregulated in psoriasis lesion tissues. In the present study, we searched for miRNAs that might be related to TNF-α and GATA3 to investigate an in-depth understanding of psoriasis pathogenesis. Herein, higher TNF-α and GATA3 protein levels were observed in psoriasis lesion tissues and that GATA3 overexpression significantly reverses TNF-α-induced increases within the production of IL-6 and CXCL8 in keratinocytes. TNF-α stimulation increases miR-155 expression dose-independently, and the miR-155 inhibitor significantly reverses TNF-α-induced suppression of GATA3 protein levels and increases IL-6 and CXCL8 production. miR-155 could suppress the expression of GATA3 by targeting its 3'UTR, while GATA3 could activate the transcription of IL37 by targeting its promoter region. miR-155 overexpression reduces IL37 protein and increases CXCL8 production; GATA3 overexpression might significantly attenuate the effects of miR-155 overexpression. In contrast to GATA3, miR-155 expression is significantly upregulated in psoriasis lesion tissue and is negatively correlated with GATA3 and IL37. In summary, the miR-155/GATA3/IL37 axis modulates the production of IL-6 and CXCL8 upon TNF-α stimulation to affect psoriasis development. Thus, miR-155/GATA3/IL37 may be potent targets for psoriasis treatment, which needs further in vivo and clinical investigation.

Repression of miR-142-3p alleviates psoriasis-like inflammation by repressing proliferation and promoting apoptosis of keratinocytes via targeting Sema3A

Psoriasis is a multifactorial, recurring, and chronic inflammatory skin disease characterized by hyperproliferation of keratinocytes. Evidence is rapidly accumulating for the role of microRNAs in psoriasis. The object of the study was to explore the functions and precise mechanism of miR-142-3p in human keratinocyte HaCaT cells in the presence of M5. Here, the results showed that miR-142-3p expression was heightened in HaCaT cells induced by M5. In addition, inhibition of miR-142-3p dramatically restricted cell proliferation and enhanced apoptosis in HaCaT cells exposed to M5, as exemplified by a decrease in the antiapoptotic Bcl-2 protein, concomitant with an increase in the proapoptotic proteins Bax. Moreover, depleting miR-142-3p effectively ameliorated M5-induced inflammation response, as reflected by the attenuation of multiple inflammatory factors. Importantly, Sema3A was identified as an authentic target of miR-142-3p, and indeed regulated by miR-142-3p. Mechanistically, silencing of Sema3A effectively abolished the anti-proliferative, apoptosis-promoting, and anti-inflammatory effects of miR-142-3p inhibition in keratinocytes. Taken together, these data elucidated that repression of miR-142-3p protect HaCaT cells against M5-induced hyper-proliferation and inflammatory injury by suppressing its target Sema3A, implying that the miR-142-3p/Sema3A axis may be a new target for preventing keratinocyte injury process. These findings provide a new and better understanding of the mediating role of miR-142-3p in psoriasis.

Comparison of MicroRNA Expression in Tears of Normal Subjects and Sjögren Syndrome Patients

Purpose

Deregulated expression of several microRNAs (miRNAs) in sera or salivary glands of patients with Sjögren syndrome (SS) has been reported. However, none have investigated miRNAs in samples that can represent lacrimal glands. We compared the miRNAs expression in the tears of SS patients and healthy controls. Moreover, we investigated the correlation between miRNAs expression and ocular staining score (OSS).

Methods

Individual tear samples were collected from 18 SS patients and 8 age-matched controls. Clinical ophthalmologic assessments included Schirmer I test, tear film breakup time (tBUT), and OSS. The expression of 43 different miRNAs in tears was measured using real-time polymerase chain reaction, and compared between the SS patients and controls. And we also compared between the three groups of control, primary SS, and secondary SS patients. The correlation between the miRNA expression and OSS was evaluated.

Results

The expression levels of miR-16-5p, miR-34a-5p, miR-142-3p, and miR-223-3p were significantly upregulated in patients with SS when compared with those in the control group (P < 0.05). The expression of 10 miRNAs (miR-30b-5p, miR-30c-5p, miR-30d-5p, miR-92a-3p, miR-134-5p, miR-137, miR-302d-5p, miR-365b-3p, miR-374c-5p, miR-487b-3p) was significantly downregulated in the SS patients (P < 0.05). Eight miRNAs showed statistically significant differences between the three groups of control, primary SS and secondary SS. All 14 miRNAs with significant differences in SS patients and control group were not significantly correlated with OSSs.

Conclusions

The 14 differentially expressed miRNAs may be involved in the pathogenesis of SS, in particular, related to autoimmunity and neuropathy.

miRNA125b Downregulation: A Review of the Novel Paradigm of Psoriasis Epigenetic Regulation

MicroRNAs (miRNAs) are small, non-protein coding ribonucleic acids (RNAs) that play a critical role in the regulation of gene expression. Change in miRNA expression has been identified in various diseases, including psoriasis. Our narrative review provides an updated overview of current research on miRNA125b and its role in psoriasis pathogenesis. We used the keywords "psoriasis, "microRNA," "miRNA," "miR," and "stRNA" to identify and select studies in PubMed, CINAHL, and Scopus databases from inception to March 2018. The references cited by the retrieved literature were reviewed to broaden our search results. miRNA125b downregulation leads to aberrant proliferation and differentiation of keratinocytes, which is a primary pathology found in psoriasis. Understanding the epigenetic alteration of miRNA125b expression and its underlying molecular mechanisms will help in identifying pathogenesis, diagnosis, and possibly curative treatment of psoriasis in the future.

Clinical Application of Circulating MicroRNAs in Parkinson's Disease: The Challenges and Opportunities as Diagnostic Biomarker

Discovery of evolutionarily conserved, nonprotein-coding, endogenous microRNAs has induced a paradigm shift in the overall understanding of gene regulation. Now, microRNAs are considered and classified as master regulators of gene expression as they regulate a wide range of processes – gene regulation, splicing, translation and posttranscriptional modifications. Besides, dysregulated microRNAs have been related to many diseases, including Parkinson's and related disorders. Several studies proposed that differentially expressed microRNAs as a potential biomarker. So far, there is no accepted clinical diagnostic test for Parkinson's disease based on biochemical analysis of biological fluids. However, circulating microRNAs possess many vital features typical of reliable biomarkers and discriminates Parkinson's patients from healthy control with much higher sensitivity and specificity. Though they show tremendous promise as a putative biomarker, translating these research findings to clinical application is often met with many obstacles. Most of the candidate microRNAs reported as a diagnostic biomarker is not organ-specific, and their overlap is low between studies. Therefore this review aimed to highlight the challenges in the application of microRNA in guiding disease discrimination decisions and its future prospects as a diagnostic biomarker in Parkinson's Disease.