Laser capture microdissection followed by next-generation sequencing identifies disease-related microRNAs in psoriatic skin that reflect systemic microRNA changes in psoriasis

The Role of Epigenetic Factors in the Pathogenesis of Psoriasis

Psoriasis is a chronic inflammatory skin disease, the prevalence of which is increasing. Genetic, genomic, and epigenetic changes play a significant role in the pathogenesis of psoriasis. This review summarizes the impact of epigenetics on the development of psoriasis and highlights challenges for the future. The development of epigenetics provides a basis for the search for genetic markers associated with the major histocompatibility complex. Genome-wide association studies have made it possible to link psoriasis to genes and therefore to epigenetics. The acquired knowledge may in the future serve as a solid foundation for developing newer, increasingly effective methods of treating psoriasis. In this narrative review, we discuss the role of epigenetic factors in the pathogenesis of psoriasis.

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.

Selected miRNA and Psoriasis-Cardiovascular Disease (CVD)-Overweight/Obesity Network-A Pilot Study

Psoriasis is nowadays recognized as a multifactorial systemic disease with complex and not fully understood pathogenesis. In psoriatic patients, the increased cardiovascular disease (CVD) risk and frequent comorbidities like obesity are observed. The aim of this study was to investigate differences in miRNA (miR-22-3p, miR-133a-3p, miR-146a-5p, miR-369-3p, and Let-7b-5p) involved in CVD risk among psoriatic patients with overweight/obesity and with normal weight. The study comprised 28 male psoriatic patients and 16 male healthy controls. miRNA isolated from peripheral blood mononuclear cells was reverse-transcribed and RT-qPCR was performed. We have found decreased levels of miR-22, miR-133a, miR-146a, and miR-369 among the psoriatic patients. There was a statistically significant difference in miR-22 and miR-146a levels between psoriatic patients with overweight/obesity and with normal weight. There were positive correlations between miR-22 and miR-146a levels and psoriatic arthritis (PsA) in psoriatic patients with normal weight and between the miR-133a level and PsA in the overweight/obese patients. The decreased levels of selected miRNA are consistent with the levels observed in CVD indicating their impact on the CVD risk in psoriatic patients. miR-22 and miR-146 may be recognized as one of the contributing factors in the obesity-CVD-psoriasis network.

Laser capture microdissection for biomedical research: towards high-throughput, multi-omics, and single-cell resolution

Spatial omics technologies have become powerful methods to provide valuable insights into cells and tissues within a complex context, significantly enhancing our understanding of the intricate and multifaceted biological system. With an increasing focus on spatial heterogeneity, there is a growing need for unbiased, spatially resolved omics technologies. Laser capture microdissection (LCM) is a cutting-edge method for acquiring spatial information that can quickly collect regions of interest (ROIs) from heterogeneous tissues, with resolutions ranging from single cells to cell populations. Thus, LCM has been widely used for studying the cellular and molecular mechanisms of diseases. This review focuses on the differences among four types of commonly used LCM technologies and their applications in omics and disease research. Key attributes of application cases are also highlighted, such as throughput and spatial resolution. In addition, we comprehensively discuss the existing challenges and the great potential of LCM in biomedical research, disease diagnosis, and targeted therapy from the perspective of high-throughput, multi-omics, and single-cell resolution.

A panel of blood-based circulatory miRNAs with diagnostic potential in patients with psoriasis

Psoriasis is a chronic inflammatory skin disease with keratinocyte hyperproliferation and T cells as key mediators of lesional and systemic inflammatory changes. To date, no suitable differential biomarkers are available for the disease diagnosis. More recently, microRNAs have been identified as critical regulators of lesional and systemic immune changes in psoriasis with diagnostic potential. We have performed expression profiling of T cell-specific miRNAs in 38 plasma samples from psoriasis vulgaris patients and an equal number of age- and gender-matched healthy subjects. Our findings have identified a panel of five blood-based circulatory miRNAs with a significant change in their expression levels, comprising miR-215, miR-148a, miR-125b-5p, miR-223, and miR-142-3p, which can differentiate psoriasis vulgaris patients from healthy individuals. The receiver operating characteristic (ROC) curves for all five miRNAs individually and in combination exhibited a significant disease discriminatory area under the curve with an AUC of 0.762 and a p < 0.0001 for all the miRNAs together. Statistically, all five miRNAs in combination depicted the best-fit model in relation to disease severity (PASI) compared with individual miRNAs, with the highest R2 value of 0.94 and the lowest AIC score of 131.8. Each of the miRNAs also exhibited a significant association with at least one of the other miRNAs in the panel. Importantly, the five miRNAs in the panel regulate one or more immune-inflammation pathways based on target prediction, pathway network analysis, and validated roles in the literature. The miRNA panel provides a rationalized combination of biomarkers that can be tested further on an expanded cohort of patients for their diagnostic value.

InflammamiR-146a and -155 Plasma Levels are Associated with Clinical Efficacy of Risankizumab Treatment in Psoriatic Patients: Pilot Study

INTRODUCTION

The key role of microRNAs (miRNAs) in the pathogenesis of psoriasis has been extensively discussed in the literature. Increasing evidence suggests that the analysis of miRNA levels may constitute an innovative approach for exploring the clinical efficacy of anti-inflammatory therapies in patients with psoriasis. However, so far there have been no published studies evaluating the effects of modulating circulating miRNAs and the efficacy of anti-interleukin-23 (anti-IL-23) therapy. The main objective of the present was to evaluate the diagnostic/prognostic relevance of the levels of five circulating candidate miRNAs (miR-21, miR-146a, miR-155, miR-210, miR-378) in psoriatic patients treated with the anti-IL-23 drug risankizumab.

METHODS

A total of eight psoriatic participants were recruited consecutively from January 2021 to July 2021 at the Dermatology Clinic of Università Politecnica delle Marche (UNIVPM) "Ospedali Riuniti" of Marche. Data on anamnestic, clinical and miRNA evaluations before the initiation of risankizumab therapy and after 1 year (January 2021-July 2022) of risankizumab therapy were available for all patients.

RESULTS

A significant reduction in the signs and symptoms in patients treated with risankizumab was observed after 1 year of treatment, suggesting that the drug is effective for treating psoriasis in a context of real-life clinical evaluation. Plasma levels of the two prototypical inflammamiRs, miR-146a and miR-155, were significantly reduced after 1 year of risankizumab therapy. Also, in patients before treatment, a significant positive correlation was found between circulating levels of miR-210 and miR-378 and disease severity scores.

CONCLUSIONS

Our results reinforce the notion that specific circulating miRNAs could have clinical relevance as diagnostic/prognostic biomarkers of psoriatic disease and suggest the potential relevance of these miRNAs as biomarkers of treatment response.

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.

Development of a Laser Microdissection-Coupled Quantitative Shotgun Lipidomic Method to Uncover Spatial Heterogeneity

Lipid metabolic disturbances are associated with several diseases, such as type 2 diabetes or malignancy. In the last two decades, high-performance mass spectrometry-based lipidomics has emerged as a valuable tool in various fields of biology. However, the evaluation of macroscopic tissue homogenates leaves often undiscovered the differences arising from micron-scale heterogeneity. Therefore, in this work, we developed a novel laser microdissection-coupled shotgun lipidomic platform, which combines quantitative and broad-range lipidome analysis with reasonable spatial resolution. The multistep approach involves the preparation of successive cryosections from tissue samples, cross-referencing of native and stained images, laser microdissection of regions of interest, in situ lipid extraction, and quantitative shotgun lipidomics. We used mouse liver and kidney as well as a 2D cell culture model to validate the novel workflow in terms of extraction efficiency, reproducibility, and linearity of quantification. We established that the limit of dissectible sample area corresponds to about ten cells while maintaining good lipidome coverage. We demonstrate the performance of the method in recognizing tissue heterogeneity on the example of a mouse hippocampus. By providing topological mapping of lipid metabolism, the novel platform might help to uncover region-specific lipidomic alterations in complex samples, including tumors.

miRNA expression profiles of the perilesional skin of atopic dermatitis and psoriasis patients are highly similar

Atopic dermatitis (AD) and psoriasis vulgaris (PV) are chronic inflammatory skin diseases with heterogeneous molecular backgrounds. MicroRNAs (miRNAs) contribute to either development or regulation of many immune system related diseases. Only few miRNA profiling studies are available for AD and no comparisons between AD and PV skin miRNA profiles have been performed recently. We conducted a miRNA profiling analysis of skin, as well as serum, from adult AD and PV patients and control individuals. 130 miRNAs were differentially expressed in AD skin, of which 77 were common differentially expressed in AD and PV. No differentially expressed miRNAs were detected in serum. Pathway analyses revealed differentially expressed miRNAs to potentially target immune-system related pathways, including TNF-α, IL-2/STAT4 and IL-6/JAK/STAT3. Additional genetic analysis of published AD GWAS dataset detected association of several target genes of differentially expressed miRNAs in skin. Moreover, miR-28-5p, miR-31-5p, miR-378a-3p and miR-203a were validated as upregulated in the skin of AD and PV patients. All validated miRNAs were reliable predictive markers for AD or PV. In conclusion, miRNA expression pattern in the skin of adult AD patients is highly similar to that of PV with multiple differentially expressed miRNAs potentially involved in the regulation of immune responses in AD and PV.

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.

The lncRNA PRINS-miRNA-mRNA Axis Gene Expression Profile as a Circulating Biomarker Panel in Psoriasis

BACKGROUND

The interaction between genes and the environment in psoriasis is firmly coupled by epigenetic modification. Epigenetic modifications are inherited variations in gene expression devoid of DNA sequence alterations. Non-coding RNAs are regarded as one of the epigenetic modifications that lead eventually to enduring heritable variations in gene expression. In the present study, we chose the lncRNA, Psoriasis-susceptibility-Related RNA Gene Induced by Stress (PRINS) known to have a regulatory role in psoriasis and deduced its axis of lncRNA-miRNA-mRNA through an in silico data analysis. We aimed to assess the expression levels of this lncRNA-miRNA-mRNA in patients with psoriasis to elucidate their possible roles in psoriasis management.

METHODS

We investigated the lncRNA-PRINS and its target microRNAs (miRNA124-3p, miRNA203a-5p, miRNA129-5p, miRNA146a-5p, miRNA9-5p) and partner genes (NPM, G1P3) expression levels in the plasma of 120 patients with psoriasis compared to 120 healthy volunteers using quantitative real-time polymerase chain reaction and correlated the results with the patients' clinicopathological data. Finally, we performed a function, disease, and pathway enrichment analysis for the LncRNA-miRNA-mRNA axis under study.

RESULTS

The lncRNA PRINS, G1P3, and NPM genes showed significantly under-expressed levels while all miRNAs included in the study showed significant over-expression in patients with psoriasis relative to controls. The lncRNA PRINS, G1P3, and NPM genes showed a significant direct correlation with each other and inverse significant correlations with all miRNAs under study. All the study biomarkers showed significant results for discriminating between patients with psoriasis and controls using a receiver operating curve analysis with sensitivity over 90% except for PRINS, which was 74.2%. The G1P3 gene showed a direct significant correlation with body mass index in patients with psoriasis (p = 0.009) and an inverse significant correlation with age (p = 0.034). The NPM gene showed a significant correlation with body mass index in patients with psoriasis (p = 0.002).

CONCLUSIONS

Based on our results, we suggest that restoring the altered PRINS-miRNA-mRNA axis gene expression levels might represent a tool to prevent psoriasis worsening, along with standard therapy. Thus, on the clinical practice level, the PRINS-miRNA-mRNA axis expression profile can be utilized in designing specific targeted therapy aimed at applying a personalized medicine approach among patients with psoriasis.

MicroRNA Cross-Involvement in Acne Vulgaris and Hidradenitis Suppurativa: A Literature Review

Acne Vulgaris (AV) and Hidradenitis suppurativa (HS) are common chronic inflammatory skin conditions that affect the follicular units that often coexist or are involved in differential diagnoses. Inflammation in both these diseases may result from shared pathways, which may partially explain their frequent coexistence. MicroRNAs (miRNAs) are a class of endogenous, short, non-protein coding, gene-silencing or promoting RNAs that may promote various inflammatory diseases. This narrative review investigates the current knowledge regarding miRNAs and their link to AV and HS. The aim is to examine the role of these molecules in the pathogenesis of AV and HS and to identify possible common miRNAs that could explain the similar characteristics of these two diseases. Five miRNA (miR-155 miR-223-, miR-21, and miRNA-146a) levels were found to be altered in both HS and AV. These miRNAs are related to pathogenetic aspects common to both pathologies, such as the regulation of the innate immune response, regulation of the Th1/Th17 axis, and fibrosis processes that induce scar formation. This review provides a starting point for further studies aimed at investigating the role of miRNAs in AV and HS for their possible use as diagnostic-therapeutic targets.

miR-378a regulates keratinocyte responsiveness to IL-17A in psoriasis

Background

Psoriasis is an immune‐mediated inflammatory skin disease, in which an interplay between infiltrating immune cells and keratinocytes sustains chronic skin inflammation. Interleukin (IL)‐17A is a key inflammatory cytokine in psoriasis and its main cellular targets are keratinocytes.

Objectives

To explore the role of miR‐378a in psoriasis.

Methods

Keratinocytes obtained from psoriatic skin and healthy epidermis were separated by magnetic sorting, and the expression of miR‐378a was analysed by quantitative polymerase chain reaction. The regulation and function of miR‐378a was studied using primary human keratinocytes. The expression of miR‐378a was modulated by synthetic mimics, and nuclear factor kappa B (NF‐κB) activity and transcriptomic changes were studied. Synthetic miR‐378a was delivered to mouse skin in conjunction with induction of psoriasiform skin inflammation by imiquimod.

Results

We show that miR‐378a is induced by IL‐17A in keratinocytes through NF‐κB, C/EBP‐β and IκBζ and that it is overexpressed in psoriatic epidermis. In cultured keratinocytes, ectopic expression of miR‐378a resulted in the nuclear translocation of p65 and enhanced NF‐κB‐driven promoter activity even in the absence of inflammatory stimuli. Moreover, miR‐378a potentiated the effect of IL‐17A on NF‐κB nuclear translocation and downstream activation of the NF‐κB pathway. Finally, injection of miR‐378a into mouse skin augmented psoriasis‐like skin inflammation with increased epidermal proliferation and induction of inflammatory mediators. Mechanistically, miR‐378a acts as a suppressor of NFKBIA/IκBζ, an important negative regulator of the NF‐κB pathway in keratinocytes.

Conclusions

Collectively, our findings identify miR‐378a as an amplifier of IL‐17A‐induced NF‐κB signalling in keratinocytes and suggest that increased miR‐378a levels contribute to the amplification of IL‐17A‐driven skin inflammation in psoriasis.

Laser Capture Microdissection in the Spatial Analysis of Epigenetic Modifications in Skin: A Comprehensive Review

Each cell in the body contains an intricate regulation for the expression of its relevant DNA. While every cell in a multicellular organism contains identical DNA, each tissue-specific cell expresses a different set of active genes. This organizational property exists in a paradigm that is largely controlled by forces external to the DNA sequence via epigenetic regulation. DNA methylation and chromatin modifications represent some of the classical epigenetic modifications that control gene expression. Complex tissues like skin consist of heterogeneous cell types that are spatially distributed and mixed. Furthermore, each individual skin cell has a unique response to physiological and pathological cues. As such, it is difficult to classify skin tissue as homogenous across all cell types and across different environmental exposures. Therefore, it would be prudent to isolate targeted tissue elements prior to any molecular analysis to avoid a possibility of confounding the sample with unwanted cell types. Laser capture microdissection (LCM) is a powerful technique used to isolate a targeted cell group with extreme microscopic precision. LCM presents itself as a solution to tackling the problem of tissue heterogeneity in molecular analysis. This review will cover an overview of LCM technology, the principals surrounding its application, and benefits of its application to the newly defined field of epigenomics, in particular of cutaneous pathology. This presents a comprehensive review about LCM and its use in the spatial analysis of skin epigenetics. Within the realm of skin pathology, this ability to isolate tissues under specific environmental stresses, such as oxidative stress, allows a far more focused investigation.

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.

MiR-193b-3p-ERBB4 axis regulates psoriasis pathogenesis via modulating cellular proliferation and inflammatory-mediator production of keratinocytes

Psoriasis is an auto-inflammatory skin disease characterized by abnormal activation of epidermal keratinocytes, aberrant neovascularization, and dysregulation of immune cells. MicroRNAs are small non-coding RNAs that mainly function in the post-transcriptional regulation of gene expression. Recently, accumulating evidence has demonstrated that expression of microRNAs is dysregulated in psoriasis patients and microRNAs play key roles in psoriasis pathogenesis. Downregulation of miR-193b-3p has been identified to be associated with psoriasis development. However, the precise functions and action mechanisms of miR-193b-3p in psoriasis pathogenesis remain unclear. In this study, we confirmed the downregulation of miR-193b-3p in psoriasis patients, psoriasis-like inflammatory cellular models, and an imiquimod (IMQ) -induced mouse model. A negative correlation was found between miR-193b-3p level and patient Psoriasis Area and Severity Index (PASI) score. Furthermore, miR-193b-3p suppressed proliferation, inflammatory-factor secretion, and the STAT3 and NF-κB signaling pathways in keratinocytes. Importantly, intradermal injection of agomiR-193b-3p blocked, whereas antagomiR-193b-3p augmented, the psoriasis-like inflammation in the IMQ-induced mouse model. Bioinformatics analysis and the dual-luciferase reporter assay showed that miR-193b-3p targets ERBB4 3' untranslated region (UTR). In addition, ERBB4 induced proliferation, inflammatory-factor production, and the STAT3 and NF-κB pathways in keratinocytes. Most importantly, forced expression of ERBB4 could attenuate the effects of miR-193b-3p in keratinocytes, indicating that miR-193b-3p inhibits keratinocyte activation by directly targeting ERBB4. In conclusion, our findings demonstrated that the miR-193b-3p-ERBB4 axis underlies the hyperproliferation and aberrant inflammatory-factor secretion of psoriatic keratinocytes, providing a novel, microRNA-related causal mechanism and a potential therapeutic target in psoriasis.

Diagnostic implications of MicroRNAs; 155, 146 a, and 203 lesional expression in alopecia areata: A preliminary case-controlled study

BACKGROUND

Alopecia areata (AA) is an immune mediated disorder that attacks hair follicles with unknown pathophysiology. MicroRNAs (miRNAs) are small noncoding RNA molecules, and their aberrant expression or function has been involved in different autoimmune conditions.

OBJECTIVES

We aimed at exploring the association between some miRNAs lesional expression and AA pathogenesis by measurement of miRNAs-155, 146a, and 203 expression levels in the lesional skin from patchy AA patients and to evaluate their relation with the studied parameters.

SUBJECTS AND METHODS

Skin expression levels of miRNAs-155, 146a, and 203 were evaluated in 50 patients with patchy AA and 25 healthy controls using reverse transcriptase-quantitative PCR (RT-qPCR). The activity and severity of alopecia were assessed according to AA Investigational Assessment Guidelines criteria.

RESULTS

Studied patients showed significant up-regulation of miRNAs-203, 146a, and 155 lesional tissue expression levels when compared to control group (p < 0.05 each). Only miRNA-146a skin expression level was significantly higher in patients with multiple lesions (p < 0.001). However, patients with active AA had significantly higher tissue expression levels of the investigated miRNAs than those with inactive disease (P 0.001, 0.009, and 0.001, respectively).

CONCLUSIONS

Investigated miRNAs seem to be role players in AA pathogenesis and may be considered potential indicators of disease activity. However, more research is needed to clarify their accurate role and clinical importance.

Kynureninase contributes to the pathogenesis of psoriasis through pro-inflammatory effect

Kynureninase (KYNU) is a key enzyme in the tryptophan metabolism pathway with elevated expression in psoriatic lesions relative to normal skin. However, whether KYNU contributes to the pathogenesis of psoriasis remains unknown. We sought to investigate the role of KYNU in psoriasis and its possible regulation mechanism. In the results, KYNU is upregulated in psoriatic skin samples from patients or animal models compared with normal skin control which was assayed in psoriatic patient samples, IMQ-induced psoriasis-like skin inflammation in BABL/c mice and M5-stimulated keratinocyte cell lines by immunohistochemistry (IHC). KYNU knockdown had a trivial impact on keratinocyte proliferation, but significantly inhibited the production of inflammatory cytokines in HaCaT, HEKα, and HEKn cells by quantitative reverse-transcription polymerase chain reaction, enzyme-linked immunosorbent assay, and western blot analysis. The 3'-untranslated region of KYNU contains a conserved target site of a skin-specific microRNA (miRNA), miR-203a, as predicted by TargetScan software. Furthermore, miR-203a exhibited an inversed expression kinetics to KYNU during the development of IMQ-induced psoriasis-like skin inflammation in BABL/c mice. Overexpression of miR-203 subsequently leading to the inhibition of KYNU, could significantly reduce the production of M5-induced, psoriasis-related inflammatory factors in keratinocytes. Finally, KYNU inhibitors could alleviate the pathological phenotypes in IMQ-mice. Our study supported the contributive role of KYNU in the development of psoriasis and provided preliminary evidence for KYNU as a potential therapeutic target in psoriasis.

Application of NGS Technology in Understanding the Pathology of Autoimmune Diseases

NGS technologies have transformed clinical diagnostics and broadly used from neonatal emergencies to adult conditions where the diagnosis cannot be made based on clinical symptoms. Autoimmune diseases reveal complicate molecular background and traditional methods could not fully capture them. Certainly, NGS technologies meet the needs of modern exploratory research, diagnostic and pharmacotherapy. Therefore, the main purpose of this review was to briefly present the application of NGS technology used in recent years in the understanding of autoimmune diseases paying particular attention to autoimmune connective tissue diseases. The main issues are presented in four parts: (a) panels, whole-genome and -exome sequencing (WGS and WES) in diagnostic, (b) Human leukocyte antigens (HLA) as a diagnostic tool, (c) RNAseq, (d) microRNA and (f) microbiome. Although all these areas of research are extensive, it seems that epigenetic impact on the development of systemic autoimmune diseases will set trends for future studies on this area.

MicroRNA-378a-3p is overexpressed in psoriasis and modulates cell cycle arrest in keratinocytes via targeting BMP2 gene

Psoriasis is a chronic autoimmune skin disease driven by dysregulations at the cellular, genomic and genetic levels. MicroRNAs are key mediators of gene expression regulation. However, how microRNAs control the pathogenesis of psoriasis is still unclear. Here, we reported a significant up-regulation of miR-378a-3p (miR-378a) in skin biopsies from active psoriatic lesions while it was down-regulated after treatment with methotrexate or narrow-band ultraviolet B phototherapy. Using the keratinocyte in vitro model, we showed that miR-378a disturbed the cell cycle progression, causing cell cycle arrest at G1 phase. Transcriptomic analysis of keratinocytes with miR-378a overexpression and depletion revealed several important biological mechanisms related to inflammation and tight junction. Target mRNA transcript assessed by luciferase assay identified bone morphogenetic protein 2 as a novel target gene of miR-378a. These findings offer a mechanistic model where miR-378a contributes to the pathogenesis of psoriasis.

microRNAs involved in psoriasis and cardiovascular diseases

Psoriasis is a chronic inflammatory disease involving the skin. Both genetic and environmental factors play a pathogenic role in psoriasis and contribute to the severity of the disease. Psoriasis, in fact, has been associated with different comorbidities such as diabetes, metabolic syndrome, gastrointestinal or kidney diseases, cardiovascular disease (CVD), and cerebrovascular diseases (CeVD). Indeed, life expectancy in severe psoriasis is reduced by up to 5 years due to CVD and CeVD. Moreover, patients with severe psoriasis have a higher prevalence of traditional cardiovascular (CV) risk factors, including dyslipidemia, diabetes, smoking, and hypertension. Further, systemic inflammation is associated with oxidative stress increase and induces endothelial damage and atherosclerosis progression. Different miRNA have been already described in psoriasis, both in the skin tissues and in the blood flow, to play a role in the progression of disease. In this review, we will summarize and discuss the most important miRNAs that play a role in psoriasis and are also linked to CVD.

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-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.

Keratinocytes Derived from Patient-Specific Induced Pluripotent Stem Cells Recapitulate the Genetic Signature of Psoriasis Disease

Psoriasis is characterized by hyperproliferation and defective differentiation of keratinocytes (KCs). Patients with psoriasis are at a high risk of developing diabetes and cardiovascular diseases. The debate on the genetic origin of psoriasis pathogenesis remains unresolved due to lack of suitable in vitro human models mimicking the disease phenotypes. In this study, we provide the first human induced pluripotent stem cell (iPSC) model for psoriasis carrying the genetic signature of the patients. iPSCs were generated from patients with psoriasis (PsO-iPSCs) and healthy donors (Ctr-iPSCs) and were efficiently differentiated into mature KCs. RNA sequencing of KCs derived from Ctr-iPSCs and PsO-iPSCs identified 361 commonly upregulated and 412 commonly downregulated genes. KCs derived from PsO-iPSCs showed dysregulated transcripts associated with psoriasis and KC differentiation, such as HLA-C, KLF4, chemokines, type I interferon-inducible genes, solute carrier family, IVL, DSG1, and HLA-DQA1, as well as transcripts associated with insulin resistance, such as IRS2, GDF15, GLUT10, and GLUT14. Our data suggest that the KC abnormalities are the main driver triggering psoriasis pathology and highlights the substantial contribution of genetic predisposition in the development of psoriasis and insulin resistance.

Plasma MicroRNA Expression Profiles in Psoriasis

Background

Psoriasis is an immune-mediated inflammatory chronic skin disease characterized by chronic inflammation in the dermis, parakeratosis, and excessive epidermal growth. MicroRNAs (miRNAs) are key regulators of immune responses. Although differential expression of miRNAs has been reported in certain inflammatory autoimmune diseases, their role in psoriasis has not been fully illuminated. Our aims were to confirm plasma miRNA expression signatures in psoriasis and to examine their potential influence on psoriasis pathogenesis.

Methods

A miRNome PCR array was used to analyse the plasma of psoriasis patients and healthy donors. We performed miRNA pathway enrichment and target gene network analyses on psoriasis plasma samples.

Results

We found several specific plasma miRNA signatures relevant to psoriasis. The miRNAs targeted pathways associated with psoriasis, such as the VEGF, MAPK, and WNT signaling pathways. Network analysis revealed pivotal deregulated plasma miRNAs and their relevant target genes and pathways regulating psoriasis pathogenesis.

Conclusions

This study analysed the expression of plasma miRNAs and their target pathways, elucidating the pathogenesis of psoriasis; these results may be used to design novel therapeutic strategies and to identify diagnostic biomarkers for psoriasis.

Epigenetics of Psoriasis

Psoriasis is a chronic and recurrent inflammatory skin disease, involving the rapid proliferation and abnormal differentiation of keratinocytes and activation of T cells. It is generally accepted that the central pathogenesis of psoriasis is a T cell-dominant immune disorder affected by multiple factors including genetic susceptibility, environmental factors, innate and adaptive immune responses, etc. However, the exact etiology is largely unknown. In recent years, epigenetic involvements, such as the DNA methylation, chromatin modifications, and noncoding RNA regulation are reported to be critical for the pathogenesis of psoriasis. However, the interplay between these factors has only recently been started to be unraveled. Notably, inhibitors of enzymes that work in epigenetic modifications, such as DNA methyltransferases and histone deacetylases, are beginning to appear in the clinical setting to restore normal epigenetic patterns (Generali et al. in J Autoimmun 83:51-61, 2017), providing novel therapeutic potential as novel treatment targets for psoriasis. Indeed, medications previously used to treat autoimmune diseases have later been discovered to exert their action via epigenetic mechanisms. Herein, we review the findings on epigenetics associated with psoriasis, and discuss future perspectives in this field.

Measurement of circulating miRNA-125a exhibits good value in the management of etanercept-treated psoriatic patients

This study aimed to explore the correlation of miR-125a with risk and severity of psoriasis, and further investigate the potential of miR-125a for predicting response to etanercept (ETN) treatment in psoriatic patients. Moderate to severe plaque psoriatic patients (n = 126) about to undergo ETN treatment for 6 months were recruited. Their plasma samples were obtained, and Psoriasis Area and Severity Index (PASI) scores and PASI-75 response rate were assessed at baseline (M0), and at 1 (M1), 3 (M3) and 6 months (M6) of treatment. Referring to PASI-75 response status at M6, patients were categorized as PASI-75 responders and PASI-75 non-responders. Healthy controls (HC, n =120) were also enrolled and their plasma samples were collected. In addition, plasma miR-125a was determined by quantitative polymerase chain reaction. miR-125a was decreased in psoriatic patients compared with HC; further, the receiver-operator curve (ROC) exhibited that miR-125a was of good value in differentiating psoriatic patients from HC with an area under the curve (AUC) of 0.802. In psoriatic patients, miR-125a was negatively associated with PASI score to some extent. Interestingly, baseline miR-125a was lower in PASI-75 responders than PASI-75 non-responders; further, ROC showed it predicted PASI-75 response at M6 to some extent with AUC of 0.672. Multivariate logistic regression also revealed that miR-125a was an independent predictive factor for worse PASI-75 response at M6. Furthermore, miR-125a expression was gradually increased during the treatment in PASI-75 responders, but unchanged in PASI-75 non-responders. Measurement of circulating miR-125a exhibits good value in the management of ETN-treated psoriatic patients.

Dietary compounds as potential modulators of microRNA expression in psoriasis

Nutrigenomic DNA reprogramming in different chronic diseases and cancer has been assessed through the stimulation of gene expression and mRNA synthesis versus DNA silencing by CpG DNA modification (methylation); histone modification (acetylation, methylation) and expression of small noncoding RNAs, known as microRNAs (miRNAs). With regard to the specific nutrigenomic effects in psoriasis, the influence of specific diets on inflammatory cell signaling transcriptional factors such as nuclear factor (NF)-κB and Wnt signaling pathways, on disease-related specific cytokine expression, pro/antioxidant balance, keratinocyte proliferation/apoptosis and on proliferation/differentiation ratio have been documented; however, the influence of dietary compounds on the balance between 'good and bad' miRNA expression has not been considered. This review aims to summarize knowledge about aberrant microRNAs expression in psoriasis and to emphasize the potential impact of some dietary compounds on endogenous miRNA synthesis in experimental conditions in vivo and in vitro. Among the aberrantly expressed miRNAs in psoriasis, one of the most prominently upregulated seems to be miR-21. The beneficial effects of phenolic compounds (curcumin and resveratrol), vitamin D, methyl donors, and omega-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid) are discussed. Highly expressed miR-155 has been downregulated by flavonoids (through a quercetin-rich diet) and by vitamin D. Quercetin has been effective in modulating miR-146a. On the other hand, downregulated miR-125b expression was restored by vitamin D, Coenzyme Q10 and by microelement selenium. In conclusion, the miRNA profile, together with other 'omics', may constitute a multifaceted approach to explore the impact of diet on psoriasis prevention and treatment.

Personalized medicine-concepts, technologies, and applications in inflammatory skin diseases

The current state, tools, and applications of personalized medicine with special emphasis on inflammatory skin diseases like psoriasis and atopic dermatitis are discussed. Inflammatory pathways are outlined as well as potential targets for monoclonal antibodies and small-molecule inhibitors.

Psoriasis Pathogenesis and Treatment

Research on psoriasis pathogenesis has largely increased knowledge on skin biology in general. In the past 15 years, breakthroughs in the understanding of the pathogenesis of psoriasis have been translated into targeted and highly effective therapies providing fundamental insights into the pathogenesis of chronic inflammatory diseases with a dominant IL-23/Th17 axis. This review discusses the mechanisms involved in the initiation and development of the disease, as well as the therapeutic options that have arisen from the dissection of the inflammatory psoriatic pathways. Our discussion begins by addressing the inflammatory pathways and key cell types initiating and perpetuating psoriatic inflammation. Next, we describe the role of genetics, associated epigenetic mechanisms, and the interaction of the skin flora in the pathophysiology of psoriasis. Finally, we include a comprehensive review of well-established widely available therapies and novel targeted drugs.

Downregulated miR-187 contributes to the keratinocytes hyperproliferation in psoriasis

Psoriasis is a common chronic skin disease characterized by epidermal hyperplasia and inflammation. However, the pathogenesis of psoriasis is multifactorial and is not fully understood. MicroRNAs (miRNAs) represent a promising class of small, noncoding RNA molecules that have a large impact on cellular functions by regulating gene expression. Here we reported that microRNA-187 (miR-187), which is one of the most dynamic microRNAs identified in the deep screening miRNAs profile, is downregulated in inflammatory cytokines-stimulated keratinocytes and psoriatic skins. By luciferase activity assay and gain-of-function studies, we showed that miR-187 inhibits keratinocytes hyperproliferation by targeting CD276. Moreover, overexpression of miR-187 decreases acanthosis and reduces the disease severity in psoriasis mouse models. Taken together, the results of our study implies miR-187 as a critical factor in psoriasis pathogenesis, which could be a potent target for psoriasis treatment.

Immune Regulation of Tissue Repair and Regeneration via miRNAs-New Therapeutic Target

The importance of immunity in tissue repair and regeneration is now evident. Thus, promoting tissue healing through immune modulation is a growing and promising field. Targeting microRNAs (miRNAs) is an appealing option since they regulate immunity through post-transcriptional gene fine-tuning in immune cells. Indeed, miRNAs are involved in inflammation as well as in its resolution by controlling immune cell phenotypes and functions. In this review, we first discuss the immunoregulatory role of miRNAs during the restoration of tissue homeostasis after injury, focusing mainly on neutrophils, macrophages and T lymphocytes. As tissue examples, we present the immunoregulatory function of miRNAs during the repair and regeneration of the heart, skeletal muscles, skin and liver. Secondly, we discuss recent technological advances for designing therapeutic strategies which target miRNAs. Specifically, we highlight the possible use of miRNAs and anti-miRNAs for promoting tissue regeneration via modulation of the immune system.

Molecular Mechanisms and Management of a Cutaneous Inflammatory Disorder: Psoriasis

Psoriasis is a complex chronic inflammatory cutaneous disorder. To date, robust molecular mechanisms of psoriasis have been reported. Among diverse aberrant immunopathogenetic mechanisms, the current model emphasizes the role of Th1 and the IL-23/Th17 axis, skin-resident immune cells and major signal transduction pathways involved in psoriasis. The multiple genetic risk loci for psoriasis have been rapidly revealed with the advent of a novel technology. Moreover, identifying epigenetic modifications could bridge the gap between genetic and environmental risk factors in psoriasis. This review will provide a better understanding of the pathogenesis of psoriasis by unraveling the complicated interplay among immunological abnormalities, genetic risk foci, epigenetic modification and environmental factors of psoriasis. With advances in molecular biology, diverse new targets are under investigation to manage psoriasis. The recent advances in treatment modalities for psoriasis based on targeted molecules are also discussed.

miR-146b Probably Assists miRNA-146a in the Suppression of Keratinocyte Proliferation and Inflammatory Responses in Psoriasis

miR-146a inhibits inflammatory responses in human keratinocytes and in different mouse models of skin inflammation. Little is known about the role of miR-146b in the skin. In this study, we confirmed the increased expression of miR-146a and miR-146b (miR-146a/b) in the lesional skin of patients with psoriasis. The expression of miR-146a was approximately twofold higher than that of miR-146b in healthy human skin, and it was more strongly induced by stimulation of proinflammatory cytokines in keratinocytes and fibroblasts. miR-146a/b target genes regulating inflammatory responses or proliferation were altered in the skin of patients with psoriasis, among which FERMT1 was verified as a direct target of miR-146a. In silico analysis of genome-wide data from >4,000 psoriasis cases and >8,000 controls confirmed a moderate association between psoriasis and genetic variants in the miR-146a encoding gene. Transfection of miR-146a/b suppressed and inhibition enhanced keratinocyte proliferation and the expression of psoriasis-related target genes. Enhanced expression of miR-146a/b-influenced genes was detected in cultured keratinocytes from miR-146a-/- and skin fibroblasts from miR-146a-/- and miR-146b-/- mice stimulated with psoriasis-associated cytokines as compared with wild-type mice. Our results indicate that besides miR-146a, miR-146b is expressed and might be capable of modulation of inflammatory responses and keratinocyte proliferation in psoriatic skin.

Roles of microRNAs in psoriasis: Immunological functions and potential biomarkers

MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in RNA silencing and post-transcriptional regulation of gene expression. Psoriasis is an inflammatory skin disease characterized by the dysfunction of keratinocytes, with the immune dysregulation. We reviewed the recent studies on the roles of miRNAs in psoriasis and showed that miRNAs play key roles in psoriasis, including the regulation of hyperproliferation, cytokine and chemokine production in keratinocyte, as well as mediating immune dysfunction in psoriasis. Furthermore, miRNAs, particularly, circulating miRNAs may serve as novel biomarkers for diagnosis, monitoring therapy response and reflecting the disease severity. Thus, targeting specific miRNAs may be used to develop new therapeutic methods for psoriasis.

The Inflammatory Response in Psoriasis: a Comprehensive Review

Psoriasis is a chronic inflammatory autoimmune disease characterized by an excessively aberrant hyperproliferation of keratinocytes. The pathogenesis of psoriasis is complex and the exact mechanism remains elusive. However, psoriasis is thought to result from a combination of genetic, epigenetic, and environmental influences. Recent studies have identified that epigenetic factors including dysregulated DNA methylation levels, abnormal histone modification and microRNAs expressions are involved in the development of psoriasis. The interplay of immune cells and cytokines is another critical factor in the pathogenesis of psoriasis. These factors or pathways include Th1/Th2 homeostasis, the Th17/Treg balance and the IL-23/Th17 axis. Th17 is believed particularly important in psoriasis due to its pro-inflammatory effects and its involvement in an integrated inflammatory loop with dendritic cells and keratinocytes, contributing to an overproduction of antimicrobial peptides, inflammatory cytokines, and chemokines that leads to amplification of the immune response. In addition, other pathways and signaling molecules have been found to be involved, including Th9, Th22, regulatory T cells, γδ T cells, CD8(+) T cells, and their related cytokines. Understanding the pathogenesis of psoriasis will allow us to develop increasingly efficient targeted treatment by blocking relevant inflammatory signaling pathways and molecules. There is no cure for psoriasis at the present time, and much of the treatment involves managing the symptoms. The biologics, while lacking the adverse effects associated with some of the traditional medications such as corticosteroids and methotrexate, have their own set of side effects, which may include reactivation of latent infections. Significant challenges remain in developing safe and efficacious novel targeted therapies that depend on a better understanding of the immunological dysfunction in psoriasis.

Recent Highlights in Psoriasis Research

This article highlights recent advances in the immunology, epidemiology, and genetics/genomics of psoriasis. Advances sometimes generate more questions, and this article makes an attempt to point out where controversies might exist in the literature. Many of the articles mentioned were published in the Journal of Investigative Dermatology, but many articles from the broader scientific literature are also cited, to provide context and to add further validity for some of these key findings. Among the themes we explore are the identification of antigens in psoriasis, the co-morbidities of psoriasis, and novel integrative approaches to genome-wide association studies.

MicroRNA-146a and miR-99a are potential biomarkers for disease activity and clinical efficacy assessment in psoriasis patients treated with traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a common chronic inflammatory skin disease. A number of clinical investigations have indicated that traditional Chinese medicine (TCM) is an effective and safe treatment for psoriasis. Zhuhuang Granule (ZG) is a modified formulation of Zhuhuang Decoction, which is used traditionally in China for the treatment of psoriasis in clinical practice.

AIM OF THE STUDY

Recent studies have found that microRNAs (miRNAs) play important roles in the pathogenesis of some skin diseases. The objective of our study was to investigate the effect of ZG on the expression of miRNAs in peripheral blood mononuclear cells (PBMCs) from psoriasis patients and to identify specific miRNA biomarkers for psoriasis disease activity and assessment of clinical efficacy.

MATERIALS AND METHODS

Twenty-five psoriasis patients and 15 healthy control subjects were recruited to participate in this study from October 2013 to October 2014. Microarray and quantitative real-time PCR (qRT-PCR) were used to measure the global miRNA expression in PBMCs from psoriasis patients and healthy control subjects. We also measured the changes in the Psoriasis Area and Severity Index (PASI) score and miRNA expression of patients before and after treatment with ZG.

RESULTS

The microarray results showed that 26 miRNAs were upregulated and 13 miRNAs were decreased in psoriasis patients. qRT-PCR validated 3 upregulated miRNAs (miR-146a, miR-31, miR-192-5p) and 2 downregulated miRNAs (miR-99a, miR-200c) in PBMCs from psoriasis patients compared with healthy controls (p<0.01). Moreover, after 8 weeks of ZG treatment, patients achieved a significant reduction in PASI scores. QRT-PCR analysis indicated that the expression of miR-146a and miR-99a is closely correlated with psoriasis severity (R²=0.772, p<0.01; R²=0.672, p<0.01).

CONCLUSION

We suggest that both miR-146a and miR-99a may serve as potential biomarkers for disease activity and clinical efficacy in psoriasis patients treated with ZG.

The role of microRNAs in the pathogenesis of autoimmune diseases

MicroRNAs (miRNAs) are single-stranded, endogenous non-coding small RNAs, ranging from 18 to 25 nucleotides in length. Growing evidence suggests that miRNAs are essential in regulating gene expression, cell development, differentiation and function. Autoimmune diseases are a family of chronic systemic inflammatory diseases. Recent findings on miRNA expression profiles have been suggesting their role as biomarkers in autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. In this review, we summarize the characteristics of miRNAs and their functional role in the immune system and autoimmune diseases including systemic lupus erythematosus, primary Sjögren's syndrome, rheumatoid arthritis, systemic sclerosis, multiple sclerosis and psoriasis; moreover, we depict the advantages of miRNAs in modern diagnostics.

microRNAs in Psoriasis

Psoriasis is a chronic inflammatory skin condition resulting from a complex interplay among the immune system, keratinocytes, susceptibility genes, and environmental factors. However, the pathogenesis of psoriasis is not completely elucidated. microRNAs represent a promising class of small, noncoding RNA molecules that function to regulate gene expression. Although microRNA research in psoriasis and dermatology is still relatively new, evidence is rapidly accumulating for the role of microRNAs in the pathogenesis of psoriasis and other chronic inflammatory conditions. In this article, we present a comprehensive review of what is known about microRNAs and their role in the pathogenesis of psoriasis.

An Exploration of the Role of MicroRNAs in Psoriasis: A Systematic Review of the Literature

Psoriasis is recently characterized by a specific microRNAs (miRNAs) expression profile, which guides the researchers' efforts to explore the therapeutic targets and objective biomarkers that reflect the diagnosis and disease activity in clinical use for psoriasis.The paper presents a state-of-the-art review of expression and function of miRNAs in psoriasis along with its clinical implications.We analyzed all literature searched by keywords "microRNA" and "psoriasis" in PubMed (Medline) from inception up to July 2015, and the references in the literature searched were also considered.Relevant literature was chosen according to the objective of this review. Relevant literature was searched by 3 independent investigators, and experts in the field of miRNAs and psoriasis were involved in analyzing process.We included any study in which role of miRNAs in psoriasis was examined in relation to disease pathogenesis, diagnosis, and treatment.The specific miRNAs profile has been identified from human psoriatic skin, blood, and hair samples. It is found that genetic polymorphisms related to some of specific miRNAs, miR-146a for example, are associated with psoriasis susceptibility. Key roles of several unique miRNAs, such as miR-203 and miR-125b, in inflammatory responses and immune dysfunction, as well as hyperproliferative disorders of psoriatic lesions have been revealed. Moreover, circulating miRNAs detected from blood samples have a potential of clinic application to be the biomarkers of diagnosis, prognosis, and treatment responses. Additionally, a new layer of regulatory mechanisms mediated by miRNAs is to some extent revealed in pathogenesis of psoriasis.The dramatically altered mRNA expression profiles are displayed in psoriasis, and some of these may become disease markers and therapeutic targets. Herein, this work underscores the potential importance of miRNAs to diagnosis, prognosis, and treatment of psoriasis. However, further study in this field is worth doing in the future, as the exact roles of miRNAs in psoriasis have not been fully elucidated.Systematic review registration number is not registered.