The eminent roles of ncRNAs in the pathogenesis of psoriasis

RNA-Based Antipsoriatic Gene Therapy: An Updated Review Focusing on Evidence from Animal Models

Psoriasis presents as a complex genetic skin disorder, characterized by the interaction between infiltrated immune cells and keratinocytes. Substantial progress has been made in understanding the molecular mechanisms of both coding and non-coding genes, which has positively impacted clinical treatment approaches. Despite extensive research into the genetic aspects of psoriasis pathogenesis, fully grasping its epigenetic component remains a challenging endeavor. In response to the pressing demand for innovative treatments to alleviate inflammatory skin disorders, various novel strategies are under consideration. These include gene therapy employing antisense nucleotides, silencing RNA complexes, stem cell therapy, and antibody-based therapy. There is a pressing requirement for a psoriasis-like animal model that replicates human psoriasis to facilitate early preclinical evaluations of these novel treatments. The authors conduct a comprehensive review of various gene therapy in different psoriasis-like animal models utilized in psoriasis research. The animals included in the list underwent skin treatments such as imiquimod application, as well as genetic and biologic injections, and the results of these interventions are detailed. Animal models play a crucial role in translating drug discoveries from the laboratory to clinical practice, and these models aid in improving the reproducibility and clinical applicability of preclinical data. Numerous animal models with characteristics similar to those of human psoriasis have proven to be useful in understanding the development of psoriasis. In this review, the article focuses on RNA-based gene therapy exploration in different types of psoriasis-like animal models to improve the treatment of 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 LINC01176-miR-218-5p-IL-36G Network is Responsible for the Pathogenesis of Psoriasis by Promoting Inflammation

Purpose

Psoriasis is an incurable chronic inflammatory skin disease. The exact function and regulatory mechanism of non-coding RNA upregulation in psoriasis remains to be elucidated. The aim of this study was to analyse the role of the lncRNA-miRNA-mRNA network of psoriasis and LINC01176 in the pathogenesis of psoriasis.

Patients and Methods

We performed miRNA, lncRNA, and mRNA sequencing analysis in pretreatment and treatment psoriatic tissues and normal tissues, constructed an lncRNA-miRNA-mRNA coexpression network and screened mRNA-associated pathways using bioinformatics analysis. We further validated the regulatory role of LINC01176-miR-218-5p on the proliferation and inflammation of the psoriatic model by dual-luciferase reporter assay, cell transfection, CCK-8 method, TUNEL staining and animal model construction method. An lncRNA-miRNA-mRNA coexpression network was successfully constructed by RNA-seq data analysis.

Results

We obtained the relationship between LINC01176, miR-218-5p and IL36-G. Analysis of the apoptotic and proliferative capacity of the transfected cells showed that miR-218-5p up-regulation significantly inhibited cell proliferation and promoted apoptosis. A mouse model of psoriasis was successfully established. Phenotypic observations revealed that keratin-forming cells in mice coated with LINC01176-shRNA emulsifier were significantly lower than those in the model group and close to those in the normal group. HE and immunohistochemical experiments were performed, and the results showed the role and mechanism of action of LINC01176-shRNA. Suppression of LINC01176 significantly inhibited the expression of IL-36G in psoriatic tissues. LINC01176 showed a targeting and positive correlation with IL36-G expression.

Conclusion

Our study shows that LINC01176 promotes the proliferation and invasion of keratinocytes and inhibits apoptosis by targeting miR-218-5p, which acts as a repressor of the psoriasis-associated IL-36G. The shRNA-LINC01176 emulsion showed potential treatment capability in alleviating symptoms of psoriasis.

RNA Pol II Assembly Affects ncRNA Expression

RNA pol II assembly occurs in the cytoplasm before translocation of the enzyme to the nucleus. Affecting this assembly influences mRNA transcription in the nucleus and mRNA decay in the cytoplasm. However, very little is known about the consequences on ncRNA synthesis. In this work, we show that impairment of RNA pol II assembly leads to a decrease in cryptic non-coding RNAs (preferentially CUTs and SUTs). This alteration is partially restored upon overcoming the assembly defect. Notably, this drop in ncRNAs is only partially dependent on the nuclear exosome, which suggests a major specific effect of enzyme assembly. Our data also point out a defect in transcription termination, which leads us to propose that CTD phosphatase Rtr1 could be involved in this process.

The role of glucose-dependent insulinotropic polypeptide 3 (G1P-3) and nucleolar phosphoprotein-1 (NPM1) in pathogenesis of psoriasis

Background Psoriasis is a multifactorial, hyperproliferative, chronic inflammatory skin disease affecting males and females equally. Aims To study the expression of certain non-coding RNAs, Interferon Alpha Inducible Protein 6 (IFI6), previously named Glucose-dependent Insulinotropic Polypeptide 3 (G1P-3), and nucleolar phosphoprotein (in serum and tissue), and to attempt to elucidate their role in the pathogenesis of psoriasis, which in turn might help in treatment. Methods Twenty patients with psoriasis and 20 healthy subjects were included in this study. Serum and skin biopsies were obtained from all participants. Molecular biology techniques were employed to estimate the expression levels of long noncoding G1P-3 and nucleolar phosphoprotein in serum and skin biopsy. Results Psoriasis patients had a mean age of 41.85 ± 12.29. The median serum G1P-3 level of the patients' group (3.330) was significantly higher than that of the control group (1.085) (P ≤ 0.001). Tissue G1P-3 level of the patients' group (6.495) was also significantly higher compared to that of controls (1.040) (P ≤ 0.001). Similarly, for nucleolar phosphoprotein, the median serum level of patients' group (2.030) was significantly higher than that of controls (1.040) (P ≤ 0.001) and median tissue level (5.425) was also significantly higher than that of controls (1.040) (P ≤ 0.001). Limitations In this study, only outpatients were included and follow-up was not well-handled. For future work, follow-up can be considered. Conclusion Long non-coding G1P-3 as well as nucleolar phosphoprotein may be considered as genetic markers for psoriasis susceptibility. In future, these might provide a novel direction for advances in psoriasis treatment.

CircVAPA contributes to hyper-proliferation and inflammation of keratinocytes through miR-125b-5p/sirt6 axis in psoriasis

Psoriasis is an autoimmune skin disease with abnormal keratinocyte hyperproliferation. The important roles of circular RNAs (circRNAs) in various inflammatory diseases have been revealed. The present study aimed to investigate the roles of circVAPA and its molecular mechanisms in psoriasis. Quantitative real-time polymerase chain reaction was performed to measure the RNA expression. Enzyme-linked immunosorbent assays were employed to examine the production of inflammatory factors. Cell-counting kit-8, EDU and flow cytometry assay were conducted to examine the cell viability, proliferation and apoptosis respectively. Dual-luciferase reporter assay and ribonucleoprotein immunoprecipitation (RIP) were conducted to verify the target relationship between miR-125b-5p and circVAPA or Sirt6. Herein our findings showed increased expression of circVAPA and Sirt6 and decreased level of miR-125b-5p in psoriatic lesional tissues and M5-stimulated keratinocytes. Mechanistically, circVAPA knockdown significantly suppressed the promotion of M5 on cell viability, proliferation, and inflammation of HaCaT cells. circVAPA was verified to interact with miR-125b-5p, while inhibition of miR-125b-5p counteracted circVAPA knockdown-mediated effects in M5-stimulated HaCaT cells. Sirt6 was confirmed as a target of miR-125b-5p, and miR-125b-5p overexpression inhibited cell growth and inflammation partly by targeting Sirt6 in M5-stimulated HaCaT cells. Moreover, circVAPA was featured as a competing endogenous RNA by directly sponging miR-125b-5p to up-regulate the expression of Sirt6. CircVAPA participate in the progression of psoriasis through miR-125b-5p/sirt6 axis by regulating proliferation and inflammation of keratinocytes, highlighting a potential therapeutic target for psoriasis.

Possible Role of lncRNA MEG3-microRNA-21 and Endoplasmic Reticulum (ER) Stress Proteins in the Pathogenesis of Psoriasis Vulgaris

BACKGROUND

Psoriasis is a chronic inflammatory immune mediated disease arising from interaction between genetic risk variants and the environment. Maternally expressed gene3 (MEG3) is a long noncoding RNA (lncRNA) known for gene transcription regulation and inhibiting proliferation. MEG3 competes with microRNA (miRNA-21) influencing cell proliferation and apoptosis balance. Endoplasmic reticulum (ER) stress proteins promote cell survival via unfolded protein response (UPR) influenced by MEG3. We aimed to detect the possible role of MEG3, miRNA-21 and ER stress proteins in pathogenesis of psoriasis vulgaris.

METHODS

Human GRP78, ATF6, caspase3 tissue levels were assayed by Enzyme Linked Immunosorbent Assay (ELISA). Assessment of long non-coding MEG3 and miRNA 21 expressions was done by quantitative real time polymerase chain reaction (qRT-PCR).

RESULTS

Expression of MEG3 was significantly downregulated, while miRNA-21 was remarkably upregulated, ER stress proteins GRP78, ATF6, and caspase 3 all showed low levels in homogenized psoriatic lesions when compared to normal skin. miRNA 21 and MEG3 were identified as possible diagnostic markers for psoriasis vulgaris.

DISCUSSION

MEG3 is barely expressed in psoriatic lesions while miRNA-21 expression is remarkably elevated but when correlated to each other there was unexpected positive correlation. MEG3 and miRNA-21 were identified as possible diagnostic markers for psoriasis. Undifferentiated psoriatic lesions have very weak UPR.

Long non-coding RNA RP11-342L8.2, derived from RNA sequencing and validated via RT-qPCR, is upregulated and correlates with disease severity in psoriasis patients

OBJECTIVE

This study aimed to explore the dysregulated long non-coding RNA (lncRNA) expression profile in psoriatic tissue vs. normal skin tissue via RNA sequencing (RNA-seq), then further sort candidate lncRNAs to be validated by reverse transcription quantitative polymerase chain reaction (RT-qPCR), in order to investigate the comprehensive linkage of lncRNA with psoriasis.

METHODS

Twenty-five psoriasis patients were consecutively enrolled, with their psoriatic and surrounding normal skin tissues obtained. Ten pairs of psoriatic and normal tissues were proposed to RNA-seq. Then, top 6 differentially expressed lncRNAs (DElncRNA) were sorted as candidate lncRNAs for validation by RT-qPCR in 25 pairs of samples.

RESULTS

Principal component analysis (PCA) exhibited that lncRNA profile clearly distinguished psoriatic tissue from normal tissue, so did heatmap. Volcano plot disclosed 412 upregulated and 625 downregulated DElncRNAs in psoriatic tissue vs. normal tissue. Gene Ontology (GO) and Kyoko Encyclopedia of Genes and Genomes (KEGG) enrichment analyses exhibited that these DElncRNAs were mainly enriched in immune, inflammation, or proliferation-related biological processes and pathways such as neutrophil degranulation, regulation of immune response, positive regulation of cell proliferation, and MAPK signaling pathway. By RT-qPCR validation, lncRNAs RP11-22A3.2, RP11-342L8.2, and CTD-2006H14.2 were increased (all P < 0.001), while lncRNAs AP000442.4, CCDC144NL-AS1, and MIR663AHG were decreased (all P < 0.01) in psoriatic tissue vs. normal tissue. Interestingly, psoriatic lncRNA RP11-342L8.2 was also observed to positively correlated with psoriasis area and severity index (PASI) (r = 0.405, P = 0.045).

CONCLUSION

Our present study exhibits some evidence for the landscape of lncRNAs implicated in psoriasis.

Recent Update on Immunopathogenesis of Psoriasis

Psoriasis is a chronic disabling complex inflammatory disorder prevalent worldwide with environmental and genetic components that involve predominantly skin in addition to nails and joints associated with various systemic comorbidities having periods of exacerbations and remissions. Psoriasis is characterized by hyper-proliferation as well as abnormal differentiation of epidermal keratinocytes and lymphocyte infiltration (mainly T cells) with resultant inflammatory cytokines and chemokines. Immunological and genetic studies over the last decade have identified genetic susceptibility risk alleles, molecular, cellular and immunological mechanisms involved in immunopathogenesis of psoriasis. The current disease model emphasizes the role of aberrant Th1 and Th17 responses regulated by a complex network of different cytokines, including TNF-α, IL-17 and IL-23; signal transduction pathways downstream to the cytokine receptors; and various activated transcription factors, including NF-κB, interferon regulatory factors and signal transducer and activator of transcriptions. Cytokines targeting biologics (IL-17, IL-23 and TNFα) therapies have revolutionized the management of severe skin disease having beneficial effects on joints and systemic inflammation of psoriasis as well. Further better understanding of immunopathogenesis of psoriasis will pave way for precision medicine based on specific immunopathogenic targets in a given phenotype of disease. Complex interplay of psoriasis with associated comorbidities is also a future area of research for overall better patient management and to improve their quality of life.

MicroRNA‐146a and microRNA‐146b deficiency correlates with exacerbated disease activity, and their longitude increment relates to etanercept response in psoriasis patients

Background

MicroRNA (miR)‐146a and miR‐146b regulate autoimmunity, inflammation, and keratinocytes proliferation to engage in psoriasis pathology. The current study aimed to investigate their correlation with disease risk and clinical features, and the linkage of their longitudinal changes with clinical response to etanercept in psoriasis patients.

Methods

Plasma samples were collected from 84 moderate‐to‐severe psoriasis patients who underwent etanercept treatment (at baseline (M0), 1 month (M1), 3 months (M3), and 6 months (M6)), 80 disease controls and 80 health controls (both after enrollment); afterward, miR‐146a and miR‐146b expressions were detected by RT‐qPCR. Furthermore, PASI75 and PASI90 responses were assessed in psoriasis patients.

Results

Both miR‐146a and miR‐146b were decreased in psoriasis patients compared with disease controls and health controls (all p < 0.001), which also distinguished psoriasis patients from disease controls and health controls by receiver‐operating characteristic analyses. Furthermore, miR‐146a positively correlated with miR‐146b in psoriasis patients (p < 0.001) and disease controls (p = 0.005) but not in healthy controls (p = 0.062). In psoriasis patients, miR‐146a negatively related to psoriatic body surface area (p = 0.011) and PASI score (p = 0.003); miR‐146b negatively linked with PASI score (p = 0.020). At M1, M3, and M6 after etanercept treatment, PASI75 response rate was 14.3%, 32.1%, and 69.0%, respectively; PASI90 response rate was 1.2%, 17.9%, and 36.9%, respectively. During etanercept treatment, both miR‐146a and miR‐146b elevated gradually over time and their longitude increments were associated with PASI75 response (all p < 0.001).

Conclusion

MiR‐146a and miR‐146b might serve as indicators for optimizing etanercept application and improving treatment outcomes in psoriasis patients.

Maximizing the Utility of Transcriptomics Data in Inflammatory Skin Diseases

Inflammatory skin diseases are induced by disorders of the host defense system of the skin, which is composed of a barrier, innate and acquired immunity, as well as the cutaneous microbiome. These disorders are characterized by recurrent cutaneous lesions and intense itch, which seriously affecting life quality of people across all ages and ethnicities. To elucidate molecular factors for typical inflammatory skin diseases (such as psoriasis and atopic dermatitis), transcriptomic profiling assays have been largely performed. Additionally, single-cell RNA sequencing (scRNA-seq) as well as spatial transcriptomic profiling have revealed multiple potential translational targets and offered guides to improve diagnosis and treatment strategies for inflammatory skin diseases. High-throughput transcriptomics data has shown unprecedented power to disclose the complex pathophysiology of inflammatory skin diseases. Here, we will summarize discoveries from transcriptomics data and discuss how to maximize the transcriptomics data to propel the development of diagnostic biomarkers and therapeutic targets in inflammatory skin diseases.

miR-145-5p inhibits psoriasis progression by regulating the Wnt/β-catenin pathway

OBJECTIVE

This research aimed to probe into the effect of miR-145-5p in psoriasis by regulating Wnt/β-catenin.

METHODS

A total of 45 psoriasis patients treated in our hospital were enrolled into an observation group (OG), and other 40 healthy individuals in physical examination over the same period were enrolled into a control group (CG). miR-145-5p in both groups was quantified, and its value in diagnosis and recurrence prediction of psoriasis was analyzed. Additionally, miR-145-5p was transfected into HaCat cells to analyze the biological behaviors of transfected cells, and factors for Wnt/β-catenin pathway inhibition were injected into cells to detect its protein expression in the cells, so as to verify the regulation of miR-145-5p on the Wnt/β-catenin pathway.

RESULTS

with low expression in the serum of psoriasis patients (P<0.05), miR-145-5p was of great application value for diagnosis and recurrence prediction. In the inhibition group, miR-145-5p increased (P<0.05), while Wnt/β-catenin pathway-related proteins decreased (P<0.05). Compared with untreated HaCat cells, the protein expression in HaCat cells treated with XAV-939 decreased (P<0.05). There was no notable difference between the miR-145-5p-mimics+XAV-939 group and the empty vector group in cell proliferation, apoptosis rate, and expression of Wnt3a, Wnt5a, and β-catenin proteins (all P>0.05); but compared with both groups, the miR-145-5p-mimics group showed lower proliferation activity, higher apoptosis rate, and higher expression of Wnt3a, Wnt5a, and β-catenin proteins (all P<0.05).

CONCLUSION

Up-regulating miR-145-5p can activate the Wnt β-catenin signal pathway, thus inhibiting psoriasis progression.

The Role of Epigenetic Factors in Psoriasis

Psoriasis is a chronic, systemic, immune-mediated disease with an incidence of approximately 2%. The pathogenesis of the disease is complex and not yet fully understood. Genetic factors play a significant role in the pathogenesis of the disease. In predisposed individuals, multiple trigger factors may contribute to disease onset and exacerbations of symptoms. Environmental factors (stress, infections, certain medications, nicotinism, alcohol, obesity) play a significant role in the pathogenesis of psoriasis. In addition, epigenetic mechanisms are considered result in modulation of individual gene expression and an increased likelihood of the disease. Studies highlight the significant role of epigenetic factors in the etiology and pathogenesis of psoriasis. Epigenetic mechanisms in psoriasis include DNA methylation, histone modifications and non-coding RNAs. Epigenetic mechanisms induce gene expression changes under the influence of chemical modifications of DNA and histones, which alter chromatin structure and activate transcription factors of selected genes, thus leading to translation of new mRNA without affecting the DNA sequence. Epigenetic factors can regulate gene expression at the transcriptional (via histone modification, DNA methylation) and posttranscriptional levels (via microRNAs and long non-coding RNAs). This study aims to present and discuss the different epigenetic mechanisms in psoriasis based on a review of the available literature.