Transcriptomic landscaping of core genes and pathways of mild and severe psoriasis vulgaris

CGF therapy: bridging androgenetic alopecia observations to psoriasis treatment via IL-17 pathway

INTRODUCTION

Concentrated Growth Factor (CGF), rich in CD34 + stem cells, is widely used in treatments for androgenetic alopecia and skin rejuvenation due to its immune-modulating properties. Psoriasis, a chronic inflammatory skin condition, presents significant treatment challenges, particularly for patients who cannot use biologics due to conditions such as cancer and lesions resistant to treatments. The potential of CGF in treating psoriasis is promising, given its broad immunoregulatory effects which confirmed in our previous androgenetic alopecia work.

METHODS

We evaluated the impact of CGF on IL-17 levels in two contexts: patients treated for androgenetic alopecia and a psoriasis mouse model. Twelve patients received three monthly injections of CGF, with serum IL-17 levels measured before and after treatment. In the psoriasis mouse model, groups were treated with CGF, and outcomes were assessed using the Psoriasis Area and Severity Index (PASI), skin barrier scores, histological analysis, and RNA sequencing. Additionally, in vitro experiments applied CD34 + cells from CGF to keratinocytes to measure levels of TNF-α, IFN-γ, IL-23, and IL-17.

RESULTS

In patients with androgenetic alopecia, three monthly CGF injections resulted in significantly reduced serum IL-17 levels. In the psoriatic mouse model, CGF-treated groups exhibited lower PASI scores and improved skin barrier scores compared to controls. Histological analysis revealed enhanced skin characteristics, while RNA sequencing demonstrated downregulated IL-17 and upregulated CD34 expression, as well as improved expression of barrier-related genes. In vitro, the application of CD34 + cells from CGF to keratinocytes led to a significant reduction in TNF-α, IFN-γ, IL-23, and IL-17 levels, indicating strong anti-inflammatory effects. A clinical case of a psoriasis patient unresponsive to IL-23 therapy (Guselkumab) showed significant improvement following CGF treatment.

CONCLUSION

These findings indicate that CGF could serve as an effective and versatile treatment for psoriasis, especially for patients who have already undergone biologic therapies but continue to experience resistant lesions.

Identification of exosome-related gene features in psoriasis and construction of a diagnostic model via integrated bioinformatics analysis

BACKGROUND

Psoriasis, a chronic inflammatory dermatosis, profoundly affects patients' well-being. Although exosomes are key in disease etiology, diagnostic potentials of associated genes are unclear. Our research targeted bioinformatics-based characterization of exosome-related genes and the development of a diagnostic model for psoriasis.

METHODS

Within GSE30999 dataset, an exosome-centric diagnostic model was formulated. Its diagnostic capability was appraised in GSE30999 and GSE14905 cohorts. Human keratinocytes (HaCaT) were used to construct psoriasis cell model. qRT-PCR was used to detect expression of diagnostic genes in the model. Construction of a protein-protein interaction network was undertaken, complemented by enrichment analyses. Comparative evaluation of immunological microenvironments between healthy controls and disease cohort was executed. Prospective miRNAs and transcription factors (TFs) were prognosticated using online prediction tools.

RESULTS

A distinctive diagnostic model with superior diagnostic performance, evidenced by an AUC value greater than 0.88, was unveiled. The model featured seven exosome-related biomarker genes (CCNA2, NDC80, CCNB1, CDCA8, KIF11, CENPF, and ASPM) interwoven in a complex network and chiefly linked in the regulation of Cell Cycle and Cellular Senescence. These genes were significantly overexpressed in psoriasis cell models. Immune infiltration analysis distinguished profound discrepancies (p < 0.05) in immunological microenvironment between disease and control groups with enrichment of T cells CD4 memory activated, Macrophages M1, and Neutrophils in the disease group. 11 miRNAs and 27 TFs were identified.

CONCLUSION

The study introduces a new and potent diagnostic model for psoriasis, with selection of credible exosome-associated biomarker genes. These discoveries aid in clinical diagnostics and research on exosome involvement in psoriasis.

Identifying key inflammatory genes in psoriasis via weighted gene co-expression network analysis: Potential targets for therapy

Psoriasis is a globally prevalent chronic inflammatory skin disease. This study aimed to scrutinize the hub genes related to inflammation and potential molecular mechanisms in psoriasis. Utilizing mRNA expression profiles from public datasets GSE13355, GSE78097, and GSE14905, we set up a comprehensive analysis. Initially, we selected differentially expressed genes (DEGs) from psoriasis and control samples in GSE13355, followed by calculating inflammatory indices using genomic set variation analysis (GSVA). Weighted gene co-expression network analysis (WGCNA) was then applied to link significant modules with the inflammatory index. This process helped us identify differentially expressed inflammation-related genes (DE-IRGs). A protein-protein interaction (PPI) network was established, with the molecular complex detection (MCODE) plug-in pinpointing six chemokine genes (CCR7, CCL2, CCL19, CXCL8, CXCL1, and CXCL2) as central hub genes. These genes demonstrated pronounced immunohistochemical staining in psoriatic tissues compared to normal skin. Notably, the CCR7 gene exhibited the highest potential for m6A modification sites. Furthermore, we constructed transcription factor-microRNA-mRNA networks, identifying 139 microRNAs and 52 transcription factors associated with the hub genes. For the LASSO logistic regression model, the area under the curve (AUC) in the training set was 1, and in the two validation cohorts GSE78097 and GSE14905 were 1 and 0.872, respectively. In conclusion, our study highlights six chemokine genes (CCR7, CCL2, CCL19, CXCL8, CXCL1, and CXCL2) as potential biomarkers in psoriasis, providing insights into the immune and inflammatory responses as pivotal instances in disease pathogenesis. These findings pave the way for exploring new therapeutic targets, particularly focusing on chemokine-associated pathways in psoriasis treatment.

Comprehensive Analysis of Crucial m6A-Related Differentially Expressed Genes in Psoriasis

BACKGROUND

Psoriasis is a common, chronic, and multifactorial inflammatory cutaneous disorder that involves genetic and epigenetic factors. N6-methyladenosine methylation (m6A) is the most prevalent RNA modification implicated in various diseases; however, its role in psoriasis still needs to be further explored. We aimed to explore the mechanisms underlying the effects of m6A in psoriasis pathogenesis, prompting new therapeutic targets.

METHODS

Three psoriasis-related datasets, including GSE155702, GSE109248, and GSE142582, were collected. Differentially m6A methylated genes (DMGs) between psoriasis lesions of psoriasis patients and healthy skin controls were identified from the GSE155702 dataset, and corresponding Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed. Differentially expressed genes (DEGs) and the common DEGs between the two groups were screened from the GSE109248 and GSE142582 datasets; the expression and interactions of the m6A regulators were analyzed. The m6A levels of total RNAs and the protein expression levels of METTL3, WTAP, ALKBH5, FTO, and METTL14 in imiquimod (IMQ)-induced psoriasiform lesions were evaluated.

RESULTS

66 significantly upregulated and 381 significantly downregulated m6A peaks were identified, corresponding to 414 genes which were particularly associated with cell and tissue development processes and cell cycle related items. 271 common DEGs were identified, associating with keratinocyte differentiation, epidermis development, cytokine-cytokine receptor interaction, and fatty acid metabolic processes. 15 crucial m6A related differentially expressed genes were obtained after the intersection of the DMGs and common DEGs, including NEU2, GALNT6, MTCL1, DOC2B, CAMK2N1, SNTB1, RNF150, CGNL1, CCDC102A, MEOX2, EEF2K, OBSCN, SLC46A2, CCDC85A, and DACH1. In addition, we found that m6A methylation and these five m6A regulators were both upregulated in psoriatic lesions.

CONCLUSIONS

It revealed that psoriasis pathophysiological processes encompass m6A epigenetic alterations, and that m6A alterations may specifically influence cell proliferation and neural regulation, and closely associated with osteoarticular involvement and metabolic syndrome in psoriasis.

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

WTAP mediated m6A-modified circ_0056856 contributes to the proliferation, migration, and invasion of IL-22-stimulated human keratinocyte by miR-197-3p/CDK1 axis

BACKGROUND

Psoriasis is a chronic inflammation-associated skin disorder, and interleukin-22 (IL-22) is involved in psoriasis pathogenesis by boosting the proliferation and migration of keratinocytes. Mounting evidence has shown that circRNAs might play an important role in several aspects of psoriasis. This study is designed to explore the role and mechanism of circ_0056856 in regulating the phenotypes of IL-22-induced keratinocytes (HaCaT cells).

METHODS

Circ_0056856, microRNA-197-3p (miR-197-3p), Cyclin-dependent kinase 1 (CDK1), and Wilms tumor 1-associated protein (WTAP) levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, proliferation, migration, and invasion were analyzed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Wound scratch, and Transwell assays. After being predicted by Circinteractome or TargetScan, binding between miR-197-3p and circ_0056856 or CDK1 was verified by a dual-luciferase reporter assay. CDK1 and WTAP protein levels were determined using Western blot. Interaction between WTAP and circ_0056856 was assessed using methylated RNA immunoprecipitation (MeRIP) assay.

RESULTS

Increased circ_0056856, CDK1, and WTAP were observed in psoriasis patients and IL-22-treated HaCaT cells. Moreover, circ_0056856 knockdown might repress IL-22-induced HaCaT cell proliferation, migration, and invasion in vitro. In mechanism, circ_0056856 might function as a sponge of miR-197-3p to modulate CDK1 expression, and WTAP improved circ_0056856 expression via m6A methylation.

CONCLUSION

WTAP-guided m6A modified circ_0056856 facilitates IL-22-stimulated HaCaT cell damage through the miR-197-3p/CDK1 axis, which could provide novel insights into psoriasis treatment.

Mass Spectrometry-Based Proteomics Analysis Unveils PTPRS Inhibits Proliferation and Inflammatory Response of Keratinocytes in Psoriasis

In this study, we used data-independent acquisition-mass spectrometry (DIA-MS) to analyze the serum proteome in psoriasis vulgaris (PsO). The serum proteomes of seven healthy controls and eight patients with PsO were analyzed using DIA-MS. Weighted gene co-expression network analysis was used to identify differentially expressed proteins (DEPs) that were closely related to PsO. Hub proteins of PsO were also identified. The Proteomics Drug Atlas 2023 was used to predict candidate hub protein drugs. To confirm the expression of the candidate factor, protein tyrosine phosphatase receptor S (PTPRS), in psoriatic lesions and the psoriatic keratinocyte model, immunohistochemical staining, quantitative real-time polymerase chain reaction, and western blotting were performed. A total of 129 DEPs were found to be closely related to PsO. The hub proteins for PsO were PVRL1, FGFR1, PTPRS, CDH2, CDH1, MCAM, and THY1. Five candidate hub protein drugs were identified: encorafenib, leupeptin, fedratinib, UNC 0631, and SCH 530348. PTPRS was identified as a common pharmacological target for these five drugs. PTPRS knockdown in keratinocytes promoted the proliferation and expression of IL-1α, IL-1β, IL-23A, TNF-α, MMP9, CXCL8, and S100A9. PTPRS expression was decreased in PsO, and PTPRS negatively regulated PsO. PTPRS may be involved in PsO pathogenesis through the inhibition of keratinocyte proliferation and inflammatory responses and is a potential treatment target for PsO.

Comparative study on gene expression in psoriatic lesions versus chronic wound healing processes

Psoriasis and chronic ulcers not only significantly impair quality of life but also pose a challenge in dermatological treatment. This study aimed to identify new therapeutic targets and biomarkers for psoriasis and chronic ulcers by comparing their gene expression profiles. The gene expression profiles of psoriatic, wound and chronic ulcer patients, as well as healthy controls, were determined via RNA extraction and next-generation sequencing of biopsies. In order to identify biomarkers, functional enrichment, differential expression analysis and machine learning algorithms were implemented. It is worth mentioning that the genes IL17A, TNF, KRT16, MMP9, and CD44 exhibited substantial correlations with the pathogenesis of the conditions being studied. As evidenced by their AUC-ROC values approaching 0.90, machine learning models accurately identified these biomarkers. The differential gene expression was consequently validated via qRT-PCR, which highlighted the increased expression of matrix remodelling enzymes and inflammatory cytokines. Additionally, genes essential for maintaining epidermis integrity and facilitating wound healing exhibited downregulation. These insights into the molecular mechanisms of psoriasis and chronic ulcers pave the way for the development of targeted therapies, offering hope for improved treatment strategies.

TNF-α promotes CXCL-1/8 production in keratinocytes by downregulating galectin-3 through NF-κB and hsa-miR-27a-3p pathway to contribute psoriasis development

OBJECTIVE

Treatment with TNF-α inhibitors improve psoriasis with minimize/minor neutrophils infiltration and CXCL-1/8 expression in psoriatic lesions. However, the fine mechanism of TNF-α initiating psoriatic inflammation by tuning keratinocytes is unclear. Our previous research identified the deficiency of intracellular galectin-3 was sufficient to promote psoriasis inflammation characterized by neutrophil accumulation. This study aims to investigate whether TNF-α participated in psoriasis development through dysregulating galectin-3 expression.

METHODS

mRNA levels were assessed through quantitative real-time PCR. Flow cytometry was used to detect cell cycle/apoptosis. Western blot was used to evaluate the activation of the NF-κB signaling pathway. HE staining and immunochemistry were used to detect epidermal thickness and MPO expression, respectively. Specific small interfering RNA (siRNA) was used to knock down hsa-miR-27a-3p while plasmids transfection was used to overexpress galectin-3. Further, the multiMiR R package was utilized to predict microRNA-target interaction.

RESULTS AND DISCUSSION

We found that TNF-α stimulation altered cell proliferation and differentiation and promoted the production of psoriasis-related inflammatory mediators along with the inhibition of galectin-3 expression in keratinocytes. Supplement of galectin-3 could counteract the rise of CXCL-1/8 but not the other phenotypes of keratinocytes induced by TNF-α. Mechanistically, inhibition of the NF-κB signaling pathway could counteract the decrease of galectin-3 and the increase of hsa-miR-27a-3p expression whereas silence of hsa-miR-27a-3p could counteract the decrease of galectin-3 expression induced by TNF-α treatment in keratinocytes. Intradermal injection of murine anti-CXCL-2 antibody greatly alleviated imiquimod-induced psoriasis-like dermatitis.

CONCLUSION

TNF-α initiates psoriatic inflammation by increasing CXCL-1/8 in keratinocytes mediated by the axis of NF-κB-hsa-miR-27a-3p-galectin-3 pathway.

Longitudinal change in CDC42 in psoriasis: correlation with disease activity and treatment response

Objective: To investigate longitudinal CDC42 change and its correlation with disease activity and treatment response in patients with psoriasis. Methods: This prospective study detected serum CDC42 at months (M) 0, M1, M3 and M6 in 150 patients with psoriasis with current initiation of topical therapy/phototherapy/systemic therapy. Results: CDC42 was positively related to systemic biologic treatment history (p = 0.025) but negatively associated with psoriatic area (p = 0.010) and Psoriasis Area Severity Index (PASI; p < 0.001). CDC42 continuously elevated from M0 to M6 (p < 0.001). CDC42 at M1/M3/M6 was enhanced in patients with current systemic biologic therapy and PASI 75 or 90 response at M6 versus those without (all p < 0.050). Conclusion: Increased serum CDC42 level reflects reduced disease severity and better treatment response in patients with psoriasis.

Inflammation modulates intercellular adhesion and mechanotransduction in human epidermis via ROCK2

Aberrant mechanotransduction and compromised epithelial barrier function are associated with numerous human pathologies including inflammatory skin disorders. However, the cytoskeletal mechanisms regulating inflammatory responses in the epidermis are not well understood. Here we addressed this question by inducing a psoriatic phenotype in human keratinocytes and reconstructed human epidermis using a cytokine stimulation model. We show that the inflammation upregulates the Rho-myosin II pathway and destabilizes adherens junctions (AJs) promoting YAP nuclear entry. The integrity of cell-cell adhesion but not the myosin II contractility per se is the determinative factor for the YAP regulation in epidermal keratinocytes. The inflammation-induced disruption of AJs, increased paracellular permeability, and YAP nuclear translocation are regulated by ROCK2, independently from myosin II activation. Using a specific inhibitor KD025, we show that ROCK2 executes its effects via cytoskeletal and transcription-dependent mechanisms to shape the inflammatory response in the epidermis.

Considerations of the Genetic Background of Obesity among Patients with Psoriasis

Psoriasis comorbidities may emerge from pleiotropic mechanisms, including common proinflammatory pathways, cellular mediators or genetic predisposition. Obesity is considered to be an independent risk factor of psoriasis, which may influence the severity of the disease and its early onset, decrease patients’ quality of life, alter response to psoriasis therapies and affect morbidity by reduced life expectancy due to cardiovascular events. Although novel approaches, including genetic techniques, have provided a wide range of new research, there are still scarce studies elaborating on the common genetic background of psoriasis and obesity. The aim of this study was to present and evaluate a possible common genetic background of psoriasis and concomitant increased body mass based on the review of the available literature.

The Potential Importance of CXCL1 in the Physiological State and in Noncancer Diseases of the Cardiovascular System, Respiratory System and Skin

In this paper, we present a literature review of the role of CXC motif chemokine ligand 1 (CXCL1) in physiology, and in selected major non-cancer diseases of the cardiovascular system, respiratory system and skin. CXCL1, a cytokine belonging to the CXC sub-family of chemokines with CXC motif chemokine receptor 2 (CXCR2) as its main receptor, causes the migration and infiltration of neutrophils to the sites of high expression. This implicates CXCL1 in many adverse conditions associated with inflammation and the accumulation of neutrophils. The aim of this study was to describe the significance of CXCL1 in selected diseases of the cardiovascular system (atherosclerosis, atrial fibrillation, chronic ischemic heart disease, hypertension, sepsis including sepsis-associated encephalopathy and sepsis-associated acute kidney injury), the respiratory system (asthma, chronic obstructive pulmonary disease (COPD), chronic rhinosinusitis, coronavirus disease 2019 (COVID-19), influenza, lung transplantation and ischemic-reperfusion injury and tuberculosis) and the skin (wound healing, psoriasis, sunburn and xeroderma pigmentosum). Additionally, the significance of CXCL1 is described in vascular physiology, such as the effects of CXCL1 on angiogenesis and arteriogenesis.

Mesenchymal stem/stromal cells primed by inflammatory cytokines alleviate psoriasis-like inflammation via the TSG-6-neutrophil axis

Psoriasis is currently an incurable skin disorder mainly driven by a chronic inflammatory response. We found that subcutaneous application of umbilical cord- derived mesenchymal stem/stromal cells (MSCs) primed by IFN-γ and TNF-α, referred to as MSCs-IT, exhibited remarkable therapeutic efficacy on imiquimod (IMQ)-induced psoriasis-like inflammation in mice. Neutrophil infiltration, a hallmark of psoriasis, was significantly reduced after treatment with MSCs-IT. We further demonstrated that the effects of MSCs-IT were mediated by tumor necrosis factor (TNF) stimulating gene-6 (TSG-6), which was greatly upregulated in MSCs upon IFN-γ and TNF-α stimulation. MSCs transduced with TSG-6 siRNA lost their therapeutic efficacy while recombinant TSG-6 applied alone could also reduce neutrophil infiltration and alleviate the psoriatic lesions. Furthermore, we demonstrated that TSG-6 could inhibit neutrophil recruitment by decreasing the expression of CXCL1, which may be related to the reduced level of STAT1 phosphorylation in the keratinocytes. Thus, blocking neutrophil recruitment by MSCs-IT or TSG-6 has potential for therapeutic application in human psoriasis.

Construction of a three commitment points for S phase entry cell cycle model and immune-related ceRNA network to explore novel therapeutic options for psoriasis

While competing endogenous RNAs (ceRNAs) play pivotal roles in various diseases, the proliferation and differentiation of keratinocytes are becoming a research focus in psoriasis. Therefore, the three commitment points for S phase entry (CP1-3) cell cycle model has pointed to a new research direction in these areas. However, it is unclear what role ceRNA regulatory mechanisms play in the interaction between keratinocytes and the immune system in psoriasis. In addition, the ceRNA network-based screening of potential therapeutic agents for psoriasis has not been explored. Therefore, we used multiple bioinformatics approaches to construct a ceRNA network for psoriasis, identified CTGF as the hub gene, and constructed a ceRNA subnetwork, after which validation datasets authenticated the results' accuracy. Subsequently, we used multiple online databases and the single-sample gene-set enrichment analysis algorithm, including the CP1-3 cell cycle model, to explore the mechanisms accounting for the increased proliferation and differentiation of keratinocytes and the possible roles of the ceRNA subnetwork in psoriasis. Next, we performed cell cycle and cell trajectory analyses based on a single-cell RNA-seq dataset of psoriatic skin biopsies. We also used weighted gene co-expression network analysis and single-gene batch correlation analysis-based gene set enrichment analysis to explore the functions of CTGF. Finally, we used the Connectivity Map to identify MS-275 (entinostat) as a novel treatment for psoriasis, SwissTargetPrediction to predict drug targets, and molecular docking to investigate the minimum binding energy and binding sites of the drug to target proteins.

CCNB1 and CCNB2 involvement in the pathogenesis of psoriasis: a bioinformatics study

Objective

The cell cycle-related proteins cyclin B1 (CCNB1) and cyclin B2 (CCNB2) are potentially involved in the underlying mechanisms of psoriasis. The present study aimed to explore this possibility using bioinformatics approaches.

Methods

CCNB1 and CCNB2 protein levels were evaluated in 14 psoriasis patients and five healthy controls by enzyme-linked immunosorbent assays, and their mRNA levels were evaluated using data from four publicly available datasets (GSE53552, GSE41664, GSE14905, and GSE13355). Comparison of high- and low-expressing groups were performed to reveal CCNB1- and CCNB2-related differentially expressed genes, which were then assessed based on gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Correlation analyses between CCNB1 and CCNB2 levels and immune infiltration, as well as typical targets of psoriasis, were also performed.

Results

Overall, 12 CCNB1 and CCNB2 common immune-related targets potentially involved in psoriasis were identified. These could regulate the cell cycle of through multiple pathways. In addition, CCNB1 and CCNB2 were found to potentially support the release of key molecular targets of psoriasis through the regulation of mast cell activation and macrophage polarization.

Conclusions

These findings suggest that CCNB1 and CCNB2 may represent valuable molecular biomarkers of psoriasis, contributing to its onset and progression.

Based on Gene Expression Analysis: Low-Density Neutrophil Expression Is a Characteristic of the Fast Responders Treated With Guselkumab for Psoriasis

Psoriasis is a worldwide chronic inflammatory skin disease. The treatment of disease is usually designed according to its severity. In this research, RNA-seq was performed on 37 patients with psoriasis treated with guselkumab before and after treatment, and the patients were divided into fast responder and slow responder according to PASI score to analyze the differentially expressed genes (DEGs) between them. Moreover, The biological mechanism of psoriasis was explored by Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, Gene Ontology (GO) analysis, and Gene Set Enrichment Analysis (GSEA) analysis. And then, this protein-protein interaction network was constructed and 17 DEGs including IL-1β, CXCL8, S100A12 and MMP9 were analyzed by GSVA. DEGs were detected by GO and KEGG analysis of target genes, which were primarily associated with immune response, neutrophil activation, neutrophil degranulation. GSEA reminded that fast responders were mainly involved in low-density neutrophils and abundant NK cells. And the GSVA showed that the DEGs were down-regulated after the early stage of the fast responder and the reverse in the slow responder by GSVA analysis. On the whole, these results indicated that these DEGs may serve as a psoriasis potential diagnostic and predictive biomarkers after been treated by guselkumab.

Circ-IGF1R plays a significant role in psoriasis via regulation of a miR-194-5p/CDK1 axis

Psoriasis is a skin disorder that is classed as an autoimmune disease. It is characterized by excessive proliferation, abnormal migration and differentiation of keratinocytes, as well as inflammatory cell infiltration. Circular RNAs (circRNAs/circ) have been reported to play an important role in several aspects of psoriasis. Thus in the present study, the role of circ-insulin-like growth factor 1 receptor (circ-IGF1R) in the development of psoriasis was assessed, and the involvement of microRNA (miR)-194-5p was also investigated as its expression was downregulated in psoriasis. StarBase analysis and dual luciferase reporter assays confirmed the interaction between circ-IGF1R with miR-194-5p. The increased expression of circ-IGF1R and decreased expression of miR-194-5p were further confirmed by reverse transcription-quantitative polymerase chain reaction in interleukin (IL-22)-stimulated HaCaT cells. The increased proliferation, migration and invasion, as well as decreased apoptosis, caspase 3 activity and cleaved-caspase 3/caspase 3 ratio were observed in IL-22-stimulated HaCaT cells. Conversely, transfection of circ-IGF1R-small interfering (si)RNA resulted in significantly increased expression of miR-194-5p with or without stimulation of IL-22 in HaCaT cells, and also overcame the effects of the miR-194-5p inhibitor. Additionally, transfection of circ-IGF1R-siRNA inhibited cell proliferation, migration and invasion, which were reversed by transfection of a miR-194-5p inhibitor. Similarly, circ-IGF1R-siRNA promoted apoptosis, caspase 3 activity and the cleaved-caspase 3/caspase 3 ratio, which were reversed by miR-194-5p inhibitor. These results showed that circ-IGF1R could affect the proliferation, apoptosis, migration and invasion of IL-22-stimulated HaCaT cells by regulating the expression of miR-194-5p. Based on TargetScan prediction and dual luciferase reporter assays, it was shown that cyclin-dependent kinase (CDK)1 was targeted by miR-194-5p. Additionally, the expression of CDK1 was upregulated following stimulation with IL-22 in HaCaT cells at the mRNA and protein levels. Transfection of miR-194-5p mimic or miR-194-5p inhibitor negatively regulated CDK1 expression in the IL-22 induced HaCaT cells. In conclusion, circ-IGF1R-siRNA could inhibit the cell proliferation, migration and invasion, and induce apoptosis by regulating the miR-194-5p/CDK1 axis. circ-IGF1R may thus serve as a potential treatment target for psoriasis.