Therapeutic Target For Psoriasis Research Articles

SerpinB7 deficiency contributes to development of psoriasis via calcium-mediated keratinocyte differentiation dysfunction

Defective execution of proteases and protease inhibitors that mediate abnormal signaling cascades is emerging as a key contributor to skin diseases, such as psoriasis. SerpinB7 is identified as a skin-specific endogenous protease inhibitor, but the role and underlying mechanism in psoriasis are poorly understood. Here we found that SerpinB7 is highly expressed in psoriatic keratinocytes of patients and imiquimod-induced psoriatic lesions in mice. SerpinB7-/- mice showed abnormal epidermal barrier integrity and skin architecture in homeostasis, and aggravated psoriatic lesion with inhibiting terminal differentiation and increasing inflammatory cells infiltration compared to SerpinB7+/+ mice after Imiquimod treatment. Mechanistically, SerpinB7 deficiency results in excessive proliferation and impaired differentiation, as well as increased chemokines and antimicrobial peptide expression in normal human epidermal keratinocyte and mouse primary keratinocyte. Transcriptomics and proteomics results showed that the SeprinB7 deficiency affected keratinocyte differentiation and proinflammatory cytokines, possibly by affecting the calcium ion channel-related proteins. Notably, we demonstrated that SerpinB7 deficiency prevented the increase in intracellular Ca2+ influx, which was partly eliminated by the intracellular Ca2+ chelator BAPTA-AM. Our findings first described the critical role of SerpinB7 in the regulation of keratinocyte differentiation and psoriatic microenvironment mediated via keratinocytes' intracellular calcium flux, proposing a new candidate for therapeutic targets in psoriasis.

Role of the long non-coding RNA, SPRR2C, based on an in vitro psoriatic keratinocyte cell model

Psoriasis is a chronic inflammatory disease of the skin with complex pathogenesis. Long non-coding RNAs (lncRNAs) play an important regulatory role in the occurrence and progression of many diseases, as well as psoriasis. This study aimed to investigate the role and mechanism of the lncRNA, SPRR2C, in M5-induced psoriatic keratinocytes. SPRR2C expression and subcellular localization was detected using FISH and qRT-PCR. Ker-CT and HaCaT cells stimulated by M5 (IL-17A, tumour necrosis factor-α, IL-1α, IL-22, and oncostatin-M) were used to establish a psoriatic cell model. CCK-8 assay, CFSE proliferation assay, flow cytometry, western blotting and ELISA were used to examine the effects of SPRR2C in the keratinocyte model. SPRR2C was highly expressed in psoriatic samples and M5-induced psoriatic keratinocytes, and SPRR2C was mainly localised to the cytoplasm. In keratinocytes, SPRR2C regulated proliferation, cell cycle and apoptosis, and induced the expression of IL-1β, IL-6, IL-8, CXCL2 and CCL20. Moreover, SPRR2C cellular effects were shown to be mediated by the PI3K/AKT/mTOR signalling pathway, based on experiments with the AKT-specific inhibitor, MK-2206, which was also shown to suppress overexpression of SPRR2C. Our results indicate that SPRR2C plays a regulatory role and is involved in the PI3K/AKT/mTOR signalling pathway in psoriatic keratinocytes, which may provide a potential diagnostic and therapeutic target for psoriasis.

Novel Therapeutic Target(s) for Psoriatic Disease.

Psoriasis and psoriatic arthritis, together known as psoriatic disease, is highly prevalent chronic relapsing inflammatory disease affecting skin, joints or both and is associated with several comorbidities such as cardiovascular, metabolic, psychiatric, renal disease etc. The etiopathogenesis of psoriasis is complex and mainly driven by aberrant immune response owing to the genetic susceptibility and various environmental factors such as trauma, infections and drugs. Recent advances in understanding molecular and cellular pathways have identified tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-23, IL-22 as major contributors in psoriasis pathogenesis. Advances in the knowledge of pathophysiology, the interaction of autoinflammation and clinical phenotypes have led to the development of highly effective targeted therapeutic agents which include TNF-α, IL-17, IL-23, IL-1 α/β or IL-36 inhibitors or receptor blockers, small molecule drugs like phosphodiesterase-4 inhibitors (apremilast), Janus kinase (JAK) inhibitors, retinoic acid receptor-related orphan receptor γt (RORγt) inhibitors. These novel drugs have promised the potential of improved disease control. In recent years, the transition from biologics to biosimilars especially with TNF-α inhibitors had significant impact on decreasing health care cost and increasing therapeutic options to the patients. However, selection of right treatment for an individual patient still remains challenging. Moreover, interplay between different epigenetic mechanisms such as the DNA methylation, chromatin modifications and noncoding RNA regulation has recently been started to be deciphered. Enzymes inhibitors involved in epigenetic pathways such as DNA methyltransferases and histone deacetylases demonstrated to restore normal epigenetic patterns in clinical settings and have provided the potential as novel therapeutic targets for psoriasis. In this review, we will discuss novel biologic agents and newer therapeutic approaches in treatment of psoriatic disease.

Integrated bioinformatic analysis of key biomarkers and signalling pathways in psoriasis.

Psoriasis is a relatively common autoimmune inflammatory skin disease with a chronic etiology. Since psoriasis is still incurable, it is necessary to identify the molecular mechanisms of psoriasis. The present study was designed to detect novel biomarkers and pathways associated with psoriasis incidence, and provide new insights into treatment of psoriasis. Differentially expressed genes (DEGs) associated with psoriasis in the Gene Expression Omnibus (GEO) database were identified, and their functional roles and interactions were then annotated and evaluated through GO, KEGG, and gene set variation (GSVA) analyses. In total 197 psoriasis-related DEGs were identified and found to primarily be associated with the NOD-like receptor, IL-17, and cytokine-cytokine receptor interaction signalling pathways. GSVA revealed significant differences between normal and lesional groups (P < 0.05), while PPI network analyses identified CXCL10 as the hub gene with the highest degree value, whereas IRF7, IFIT3, OAS1, GBP1, and ISG15 were promising candidate genes for the therapeutic treatment of psoriasis. The findings of the present integrated bioinformatics may enhance our understanding of the molecular events occurring in psoriasis, and these candidate genes and pathways together may prove to be therapeutic targets for psoriasis.

MicroRNA-17-3p is upregulated in psoriasis and regulates keratinocyte hyperproliferation and pro-inflammatory cytokine secretion by targeting CTR9.

Psoriasis is a chronic inflammatory skin disease. Although miRNAs are reported to be associated with the pathogenesis of psoriasis, the contribution of individual microRNAs toward psoriasis remains unclear. The miR-17-92 cluster regulates cell growth and immune functions that are associated with psoriasis. miR-17-3p is a member of miR-17-92 cluster; however, its role in dermatological diseases remains unclear. Our study aims at investigating the effects of miR-17-3p and its potential target gene on keratinocytes proliferation and secretion of pro-inflammatory cytokine and their involvement in psoriasis. Initially, we found that miR-17-3p was upregulated in psoriatic skin lesions, and bioinformatic analyses suggested that CTR9 is likely to be a target gene of miR-17-3p. Quantitative reverse-transcriptase PCR and immunohistochemical analysis revealed that CTR9 expression was downregulated in psoriatic lesions. Using dual-luciferase reporter assays, we identified CTR9 as a direct target of miR-17-3p. Further functional experiments demonstrated that miR-17-3p promoted the proliferation and pro-inflammatory cytokine secretion of keratinocytes, whereas CTR9 exerted the opposite effects. Gain-of-function studies confirmed that CTR9 suppression partially accounted for the effects of miR- 17-3p in keratinocytes. Furthermore, Western blot revealed that miR-17-3p activates the downstream STAT3 signaling pathway while CTR9 inactivates the STAT3 signaling pathway. Together, these findings indicate that miR-17-3p regulates keratinocyte proliferation and pro-inflammatory cytokine secretion partially by targeting the CTR9, which inactivates the downstream STAT3 protein, implying that miR-17-3p might be a novel therapeutic target for psoriasis.

Update on the etiopathogenesis of psoriasis (Review).

Psoriasis is one of the most common immune-mediated chronic inflammatory skin disorders, involving hyperproliferative keratinocytes and infiltration of T cells, dendritic cells, macrophages, and neutrophils. Multiple factors appear to play important roles in the pathogenesis of psoriasis. These environmental (e.g., infectious agents and trauma), genetic, and immunologic factors are reviewed in this article. Although the pathogenesis of psoriasis remains to be established, data suggesting immune cell dysregulation in the skin are available. The involvement of the immune system, particularly T cells, in the etiopathogenesis of psoriasis is discussed in this review, indicating a potential justification for innovative treatment intervention. Besides describing pathogenic T cells, the aim of the review was to assess the function of newly identified antimicrobial peptides (AMPs), interleukin (IL)-23, IL-17, and tissue resident memory cells (TRMs), and their role in psoriasis. Furthermore, new insights were presented regarding TRMs, a recently identified subset of memory T cells, and the role they play in the local memory of disease, making them a potential new therapeutic target in psoriasis. Finally, current developments in T-cell research and cytokine-targeted therapy for psoriasis treatment are reviewed.

RIPK1 downregulation enhances neutrophil extracellular traps in psoriasis.

IntroductionPsoriasis is an immune-mediated systemic disease. Neutrophils are enriched in psoriasis lesions and can form neutrophil extracellular traps (NETs) to activate keratinocytes. Receptor-interacting protein kinase RIPK1 and RIPK3 are involved in necroptosis and NET formation.AimTo elucidate whether RIPK1 regulates circulating neutrophils to form NETs and inflammation in psoriasis.Material and methodsBlood samples of psoriasis patients (n = 20) and healthy controls (n = 20) were detected by flow cytometry. The expression level of RIPK1/3 in isolated circulating neutrophils from psoriasis patients (n = 17) and healthy controls (n = 17) was examined by quantitative real-time PCR. SYTOX Green dye and PicoGreen reagent were used to detect NET formation and DNA release in neutrophils under the stimulation of phorbol 12-myristate 13-acetate (PMA) and necrostain-1 (Nec-1). Correlation analysis was performed between RIPK1/3 expression and Psoriasis Area Severity Index (PASI), neutrophil-to-lymphocyte ratio (NLR).ResultsRIPK1 and RIPK3 expression in protein levels were decreased in monocytes and neutrophils from peripheral blood of psoriasis patients. In isolated psoriasis neutrophils, RIPK1 and Caspase8 mRNA were downregulated while RIPK3 and MLKL mRNA were elevated, leading to the necroptosis pathway. In addition, RIPK1-inhitor-necrostatin-1 (Nec-1) enhanced NETosis in psoriasis neutrophils in vitro. More importantly, there is a negative correlation between RIPK1 and psoriasis disease severity.ConclusionsOur data demonstrated that downregulated RIPK1 expression in psoriasis neutrophils may enhance NET generation. RIPK1 may be identified as a novel therapeutic target in psoriasis.

N6-methyladenosine-modified long non-coding RNA AGAP2-AS1 promotes psoriasis pathogenesis via miR-424–5p/AKT3 axis

BackgroundPsoriasis is a chronic, complicated, and recurrent inflammatory skin disease. However, the precise molecular mechanisms remain largely elusive and the present treatment is unsatisfactory. ObjectiveThis study aimed to unravel the functions of long noncoding RNA (lncRNA) AGAP2-AS1 and its biological mechanism in psoriasis pathogenesis, hinting for the new therapeutic targets in psoriasis. MethodsThe expression of AGAP2-AS1 in the skin tissue of psoriasis patients and healthy controls were detected by qRT-PCR and RNAscope®. Cell Counting Kit‑8 (CCK8) and clone formation assays were utilized to assess proliferation. Methylated RNA immunoprecipitation (MeRIP) was performed to detect the N6-methyladenosine (m6A) modification. RNA immunoprecipitation (RIP) was used to detect the interaction of AGAP2-AS1 with YTH domain family 2(YTHDF2). The relationships among AGAP2-AS1, miR-424–5p and AKT3 were examined by dual-luciferase reporter assay and RIP assay. ResultsWe found that AGAP2-AS1 level was upregulated in the skin tissue of psoriasis patients than that of healthy controls and AGAP2-AS1 could promote proliferation and inhibit apoptosis of keratinocytes. Methyltransferase like 3(METTL3)-mediated m6A modification suppressed the expression of AGAP2-AS1 via YTHDF2-dependent AGAP2-AS1 stability. Thus, downregulation of METTL3 resulted in the upregulation of AGAP2-AS1 in psoriasis. AGAP2-AS1 functioned as a competitive endogenous RNA by sponging miR-424–5p to upregulate AKT3, activate AKT/mTOR pathway, as well as promote cell proliferation in keratinocytes. ConclusionAGAP2-AS1 is upregulated in the skin tissue of psoriasis patients and m6A methylation was involved in its upregulation. AGAP2-AS1 promotes keratinocyte proliferation through miR-424–5p/AKT/mTOR axis and may be a promising target for psoriasis therapy.

ERAP1 Controls the Autoimmune Response against Melanocytes in Psoriasis by Generating the Melanocyte Autoantigen and Regulating Its Amount for HLA-C*06:02 Presentation.

Autoimmune diseases develop when autoantigens activate previously quiescent self-reactive lymphocytes. Gene-gene interaction between certain HLA class I risk alleles and variants of the endoplasmic reticulum aminopeptidase ERAP1 controls the risk for common immune-mediated diseases, including psoriasis, ankylosing spondylitis, and Behçet disease. The functional mechanisms underlying this statistical association are unknown. In psoriasis, HLA-C*06:02 mediates an autoimmune response against melanocytes by autoantigen presentation. Using various genetically modified cell lines together with an autoreactive psoriatic TCR in a TCR activation assay, we demonstrate in this study that in psoriasis, ERAP1 generates the causative melanocyte autoantigen through trimming N-terminal elongated peptide precursors to the appropriate length for presentation by HLA-C*06:02. An ERAP1 risk haplotype for psoriasis produced the autoantigen much more efficiently and increased HLA-C expression and stimulation of the psoriatic TCR by melanocytes significantly more than a protective haplotype. Compared with the overall HLA class I molecules, cell surface expression of HLA-C decreased significantly more upon ERAP1 knockout. The combined upregulation of ERAP1 and HLA-C on melanocytes in psoriasis lesions emphasizes the pathogenic relevance of their interaction in patients. We conclude that in psoriasis pathogenesis, the increased generation of an ERAP1-dependent autoantigen by an ERAP1 risk haplotype enhances the likelihood that autoantigen presentation by HLA-C*06:02 will exceed the threshold for activation of potentially autoreactive T cells, thereby triggering CD8+ T cell-mediated autoimmune disease. These data identify ERAP1 function as a central checkpoint and promising therapeutic target in psoriasis and possibly other HLA class I-associated diseases with a similar genetic predisposition.

MiR-193b-3p\u2013ERBB4 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 3ʹ 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.

169 Eukaryotic Translation Initiation Factors (eIFs): Potential Therapeutic Targets in Psoriasis

Background: eIFs play a critical role in the regulation of gene expression in eukaryotes ans affect many essential cellular processes, including proliferation, apoptosis and differentiation. Purpose of the study: We hypothesized that eIFs are involved in the pathophysiology of psoriasis, are affected by anti-psoriatic treatments, and can serve as direct targets for anti-psoriatic treatment. Experimenetal design: We used the IMQ and TGFß transgenic mouse models, human psoriasis samples (lesional psoriatic and healthy control skin) as well as an 3D in vitro model of psoriasis to enable the study of the disease, and to screen therapeutic candidates (eIF1A and eIF3B) to assess the therapeutic potential and to determine the molecular mechanisms related to anti-psoriatic response with regard to the translation initiation machinery. Results: Our preliminary data showed significant increase of eIF1A and eIF3B in human psoriasis lesions, IMQ and TGFß mice, as well as in HaCaT cells on protein and mRNA level. Our preliminary 3D in vitro model and mouse model (IMQ and TGFß) data revealed that a systemically and topically treatment with eIF1A and eIF3B siRNA decrease epidermis and dermis thickness as well as reduced mRNA expression for eIF1A and eIF3B after treatment. Conclusion: We have demonstrated for the first time an increased expression of eIF1A and and eIF3B in psoriatic skin. This project will extend the knowledge of the mechanisms behind the translation initiation in particular of eIFs in psoriasis, but may also reveal novel cellular processes regulated by eIFs. Together, this may open up new therapeutic avenues by targeting eIFs in psoriasis.

Losartan ointment attenuates imiquimod-induced psoriasis-like inflammation

BackgroundPsoriasis is a chronic skin condition associated with interleukin-23/interleukin-17 (IL-23/IL-17) pathway. Recent evidence declares that angiotensin II (Ang II) induces a potent IL-17-related inflammation. Meanwhile, Losartan, an angiotensin one receptor (AT1R) antagonist, attenuates the TH17-related responses. Therefore, we investigated the possible beneficial effects of topically applied Losartan1% ointment on imiquimod (IMQ)-induced psoriasis in mice. MethodPsoriasis was induced in mice consecutively for five days by topical IMQ on the shaved back. The IMQ-induced psoriasis was treated via topical administration of Losartan1% twice a day. The severity of skin inflammation was evaluated employing Psoriasis Area and Severity Index (PASI) scores. Subsequently, the skin samples were assessed using Baker's scoring system, stereological studies, and biochemical assessment with real-time PCR and immunohistochemistry. ResultsIMQ administration induced plaque-type psoriasis and skin inflammation. We characterized psoriatic lesions by hyperkeratosis, Munro abscess, rete ridges, and marked T-cell infiltrates. IMQ significantly increased epidermal volume, mRNA expression of IL-17a, IL-23, Ang II, AT1R, and TNF-α levels compared with the Placebo group. Topical administration of Losartan1% on IMQ-induced psoriasis significantly reduced the PASI scores and alleviated the erythema and scaling. The treatment significantly decreased the psoriatic thickness and dermal T-cell infiltration. Regarding biochemical assessment, Losartan1% considerably reduced the IMQ-induced increase of IL-17a, Ang II, and AT1R expression in the skin. ConclusionTopical Losartan1% significantly alleviates psoriasis by reducing AT1R and IL-17a expression. Our results introduce AT1Rs as a promising therapeutic target in psoriasis and represent a link between angiotensin and TH17-related inflammation. However, the effects of AngII-AT1R systems on IL-17 signaling need to be confirmed by further investigations.

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.

Downregulation of interleukin 36γ and its cleaver cathepsin G following treatment with narrow-band ultraviolet B phototherapy in psoriasis vulgaris

Background Growing evidence suggests the important role of IL-36 in the pathogenesis of psoriasis. Cathepsin G is a neutrophil-derived protease that can activate IL-36γ. Objective To assess the expression of IL-36γ and cathepsin G in psoriasis and to quantify the impact of treatment with narrow-band ultraviolet B phototherapy (NB-UVB) on their levels. Methods This case-control study involved 26 patients with moderate-severe psoriasis and 25 healthy volunteers. Psoriasis patients eligible for phototherapy received 24 NB-UVB sessions. Punch skin biopsies were obtained from all participants at recruitment and after phototherapy from patients. Real-time PCR was utilized for quantitative assessment of IL-36γ and cathepsin G expression in tissue samples. Results The expression of IL-36γ and cathepsin G was significantly higher in psoriasis before NB-UVB therapy compared to controls (p < .001). Both proteins decreased significantly with clinical improvement following NB-UVB therapy compared to baseline (p < .001). However, their expression after treatment was still higher than controls (p < .001). Conclusion IL-36γ and cathepsin G expression is upregulated in psoriatic lesions, supporting their role as mediators of inflammation in psoriasis. Downregulation of IL-36γ and cathepsin G is a possible mechanism for psoriasis improvement after NB-UVB therapy. IL-36 and cathepsin G can be considered as therapeutic targets for psoriasis.

Mitochondrial Reactive Oxygen Species Are Essential for the Development of Psoriatic Inflammation

Psoriasis is a common immune-mediated, chronic, inflammatory skin disease that affects approximately 2–3% of the population worldwide. Although there is increasing evidence regarding the essential roles of the interleukin (IL)-23/IL-17 axis and dendritic cell (DC)-T cell crosstalk in the development of skin inflammation, the contributions of mitochondrial function to psoriasis are unclear. In a mouse model of imiquimod (IMQ)-induced psoriasiform skin inflammation, we found that hematopoietic cell-specific genetic deletion of p32/C1qbp, a regulator of mitochondrial protein synthesis and metabolism, protects mice from IMQ-induced psoriatic inflammation. Additionally, we demonstrate that p32/C1qbp is an important regulator of IMQ-induced DC activation, both in vivo and in vitro. We also found that p32/C1qbp-deficient DCs exhibited impaired production of IL-1β, IL-23, and mitochondrial reactive oxygen species (mtROS) after IMQ stimulation. Because the inhibition of mtROS suppressed IMQ-induced DC activation and psoriatic inflammation, we presume that p32/C1qbp and mtROS can serve as therapeutic targets in psoriasis.

A Computational Systems Analyses to Identify Biomarkers and Mechanistic Link in Psoriasis and Cutaneous Squamous Cell Carcinoma.

Psoriasis is the most common and chronic skin disease that affects individuals from every age group. The rate of psoriasis is increasing over the time in both developed and developing countries. Studies have revealed the possibility of association of psoriasis with skin cancers, particularly non-melanoma skin cancers (NMSC), which, include basal cell carcinoma and cutaneous squamous cell carcinoma (cSCC). There is a need to analyze the disease at molecular level to propose potential biomarkers and therapeutic targets in comparison to cSCC. Therefore, the second analyzed disease of this study is cSCC. It is the second most common prevalent skin cancer all over the world with the potential to metastasize and recur. There is an urge to validate the proposed biomarkers and discover new potential biomarkers as well. In order to achieve the goals and objectives of the study, microarray and RNA-sequencing data analyses were performed followed by network analysis. Afterwards, quantitative systems biology was implemented to analyze the results at a holistic level. The aim was to predict the molecular patterns that can lead psoriasis to cancer. The current study proposed potential biomarkers and therapeutic targets for psoriasis and cSCC. IL-17 signaling pathway is also identified as significant pathway in both diseases. Moreover, the current study proposed that autoimmune pathology, neutrophil recruitment, and immunity to extracellular pathogens are sensitive towards MAPKs (MAPK13 and MAPK14) and genes for AP-1 (FOSL1 and FOS). Therefore, these genes should be further studied in gene knock down based studies as they may play significant role in leading psoriasis towards cancer.

SerpinB7 deficiency contributes to development of psoriasis via Calcium-mediated keratinocyte differentiation dysfunction

Abstract Defective execution of protease and protease inhibitor, which meditates abnormal signaling cascade, is merging as key contributors to autoimmune disease. SerpinB7, is identified as a skin-specific endogenous protease inhibitor, the role and underlying mechanism in psoriasis is poorly understood. Here we found that SerpinB7 is highly expressed in psoriatic keratinocytes of patient and imiquimod-induced psoriatic lesion in mice. SerpinB7−/− mice showed abnormal epidermal barrier integrity and skin architecture in homeostasis, and aggravated psoriatic lesion with inhibiting terminal differentiation and increasing inflammatory cells infiltration compared to WT after IMQ treatment. Mechanistically, SerpinB7 deficiency resulted in excessive proliferation and impaired differentiation, as well as increased chemokines and antimicrobial peptide expression in human epidermal keratinocyte and mouse primary keratinocyte. Transcriptome analysis demonstrate that SerpinB7 has a significant correlation with keratinocyte differentiation, consistent with WGCNA analysis from GTEx. Notably, we demonstrated that SerpinB7 deficiency prevented the increase of intracellular Ca2+ influx and the generation of mitochondria-derived reactive oxygen species (ROS), which were partly eliminated by antioxidant NAC and intracellular Ca2+ chelator BAPTA-AM. More importantly, iTraq and iTraq-tail proteomics demostrated SerpinB7 deficiency attenuated proteolytic networks that control calcium flux in keratinocytes. Our findings first described the critical role of SerpinB7 in the regulation of keratinocytes differentiation and psoriatic microenvironment, implying a new candidate for therapeutic targets in psoriasis.

Ultraviolet B irradiation decreases CXCL10 expression in keratinocytes through endoplasmic reticulum stress.

Ultraviolet radiation is one of the standard treatment selections for psoriasis. interferon (IFN)-γ and IFN-γ-induced CXCL10, which are highly expressed by keratinocytes in psoriasis lesion, are therapeutic targets for psoriasis. In this study, we found that ultraviolet B (UVB) irradiation inhibited IFN-γ signaling events, including STAT1 phosphorylation and induction of CXCL10 messenger RNA (mRNA) expression in keratinocytes. IFN-γ-induced expression of CXCL10 mRNA in HaCaT cells, a human keratinocyte cell line, and human epithelial keratinocytes were also inhibited by H2 O2 or endoplasmic reticulum (ER) stress inducers. Conversely, a mixture of antioxidants, Trolox and ascorbic acid, and the ER stress inhibitor salubrinal partially counteracted the inhibitory effect of UVB on IFN-γ-induced CXCL10 mRNA expression in HaCaT cells. We also found that UVB and ER stress reduced IFN-γ receptor 1 protein levels in the plasma membrane fraction of keratinocytes. These observations suggested that ER stress and the generation of reactive oxygen species are essential for the inhibitory effect of UVB on IFN-γ-induced CXCL10 mRNA in keratinocytes.

MicroRNA-125a Correlates with Decreased Psoriasis Severity and Inflammation and Represses Keratinocyte Proliferation

Background: Psoriasis has a complex etiology related to inflammation and dysregulated immune system. MicroRNA (miR)-125a is a miRNA intimately related to inflammation and immunity; therefore, we presumed that it might play a role in the pathogenesis of psoriasis. This study aimed to investigate the correlation of miR-125a with disease severity and inflammation in psoriasis patients, and the effect of miR-125a on proliferation, apoptosis as well as its target signaling pathway in keratinocytes. Methods: Sixty psoriasis patients were consecutively recruited, then lesional and non-lesional skin tissue samples were collected. miR-125a in lesional and non-lesional skin tissues, tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-17 mRNA expressions in lesional skin tissues were detected. Then, miR-125a overexpression, control overexpression, miR-125a knockdown and control knockdown plasmids were transfected into HaCaT cells. Subsequently, cell proliferation, apoptosis, IL-23R, JAK2, and STAT3 expressions were assessed. Results: miR-125a was reduced in lesional skin tissue compared with non-lesional skin tissue (p < 0.001), and it distinguished lesional skin tissue from non-lesional skin tissue with a high area under curve of 0.917 (95% CI 0.866–0.968). Negative association of miR-125a in lesional skin tissue with lesional body surface area (p = 0.037) and psoriasis area and severity index score (p < 0.001) was found. Additionally, miR-125a was negatively correlated with TNF-α (p = 0.001), IL-1β (p = 0.014), and IL-17 (p = 0.003) in lesional skin tissue. In cellular experiments, miR-125a overexpression inhibited proliferation and promoted apoptosis, while miR-125a knockdown enhanced proliferation and repressed apoptosis in HaCaT cells. Additionally, miR-125a negatively regulated the IL-23R/JAK2/STAT3 pathway in HaCaT cells. Conclusion: miR-125a could facilitate the disease monitoring and probably has the potential to be a therapeutic target in psoriasis.

Psoriatic skin inflammation is promoted by c‐Jun/AP‐1‐dependent CCL2 and IL‐23 expression in dendritic cells

Toll‐like receptor (TLR) stimulation induces innate immune responses involved in many inflammatory disorders including psoriasis. Although activation of the AP‐1 transcription factor complex is common in TLR signaling, the specific involvement and induced targets remain poorly understood. Here, we investigated the role of c‐Jun/AP‐1 protein in skin inflammation following TLR7 activation using human psoriatic skin, dendritic cells (DC), and genetically engineered mouse models. We show that c‐Jun regulates CCL2 production in DCs leading to impaired recruitment of plasmacytoid DCs to inflamed skin after treatment with the TLR7/8 agonist Imiquimod. Furthermore, deletion of c‐Jun in DCs or chemical blockade of JNK/c‐Jun signaling ameliorates psoriasis‐like skin inflammation by reducing IL‐23 production in DCs. Importantly, the control of IL‐23 and CCL2 by c‐Jun is most pronounced in murine type‐2 DCs. CCL2 and IL‐23 expression co‐localize with c‐Jun in type‐2/inflammatory DCs in human psoriatic skin and JNK‐AP‐1 inhibition reduces the expression of these targets in TLR7/8‐stimulated human DCs. Therefore, c‐Jun/AP‐1 is a central driver of TLR7‐induced immune responses by DCs and JNK/c‐Jun a potential therapeutic target in psoriasis.