Immunopathogenesis of psoriasis

Rare MED12L Variants Are Associated with Susceptibility to Guttate Psoriasis in the Han Chinese Population

INTRODUCTION

According to the common disease/rare variant hypothesis, it is important to study the role of rare variants in complex diseases. The association of rare variants with psoriasis has been demonstrated, but the association between rare variants and specific clinical subtypes of psoriasis has not been investigated.

METHODS

Gene-based and gene-level meta-analyses were performed on data extracted from our previous study data sets (2,483 patients with guttate psoriasis and 8,292 patients with non-guttate psoriasis) for genotyping. Then, haplotype analysis was performed for rare loss-of-function variants located in MED12L, and protein function prediction was performed for MED12L. Gene-based analysis at each stage had a moderate significance threshold (p < 0.05). A χ2 test was then conducted on the three potential genes, and the merged gene-based analysis was used to confirm the results. We also conducted association analysis and meta-analysis for functional variants located on the identified gene.

RESULTS

Through these gene-level analyses, we determined that MED12L is a guttate psoriasis susceptibility gene (p = 9.99 × 10-5), and the single-nucleotide polymorphism with the strongest association was rs199780529 (p_combine = 1 × 10-3, p_meta = 2 × 10-3).

CONCLUSIONS

In our study, a guttate psoriasis-specific subtype-associated susceptibility gene was confirmed in a Chinese Han population. These findings contribute to a better genetic understanding of different subtypes of psoriasis.

Design, Synthesis, and Biological Evaluation of an Orally Bioavailable, Potent, and Selective ROCK2 Inhibitor for Psoriasis Treatment

Psoriasis, a prevalent chronic skin disorder, remains a significant therapeutic obstacle. This study centers on rho-associated coiled-coil-containing kinase2 (ROCK2) as an advantageous target for treating psoriasis and identifies five potent and selective ROCK2 inhibitors (A31-35). Notably, A32-35 outperform KD025 in ROCK2/ROCK1 selectivity by up to 216-fold. Among these candidates, A31 emerged as an exceedingly promising molecule, showcasing remarkable inhibitory potency (IC50 = 3.7 ± 0.8 nM), 19-fold ROCK2/ROCK1 selectivity, and favorable pharmacokinetics. Insights from the binding mode study further underscored the pivotal role of interactions with Phe103 on the P-loop in determining the selectivity between ROCK1 and ROCK2. In an imiquimod-induced psoriasis-like mouse model, oral administration of A31 notably ameliorated symptoms by targeting the IL-23/Th17 axis. Based on these compelling findings, A31 was selected as a highly promising compound for further investigation as a potential treatment for psoriasis.

Psoriasis and skin cancer - Is there a link?

A chronic auto-immune-mediated disease Psoriasis is associated with manycoexisting or co-occurringconditions, which include a significant risk of malignancies, especiallyskin tumours. Numerous studies were done to understand whether psoriasis itself, comorbidities related to psoriasis, or psoriasis treatment might increase the risk of neoplasms. We reviewed the relation between psoriasis and cancer risk, also the significance of inflammation in cancer The various classes of drugs used to treat psoriasis, including biologics like tumour necrosis factor (TNF) inhibitors; and how they increase cancer risk are deliberated. Literature was collated for the past five years from the data bases like PubMed, Medline, Google Scholar, etc. Literatures discussing the skin cancer linked to psoriasis were reviewed. Possible mechanisms associated between inflammation and psoriasis; skin cancer was explained in the context of the several psoriasis medications that increase the likelihood of skin cancer. The risk of cancer in other cutaneous auto-inflammatory diseases is also elucidated. It is frequently observed that increased doses of PUVA therapy, immunosuppressive medications, and lifestyle changes alter the aetiology of the tumours. This review is conceptualized to shed the light on probable mechanisms involved in these connections as well as the chance of cancer in psoriasis patients.

An optical system for noninvasive microscopy of psoriatic mice in vivo

Psoriasis is a chronic inflammatory skin disease involved with both complex morphological changes of skin and immune processes. The clinical diagnostics and research of psoriasis often require invasive biopsy which lacks their real-time dynamics in vivo. Here we report a noninvasive microscopic system developed by combining in vivo fluorescent microscopy, optical clearing, and immunolabeling to enable real-time imaging of immune cells and cytokines in blood flow in psoriatic animal models. The vascular morphology and time-lapse kinetics of interleukin (IL)-23, IL-17, tumor necrosis factor-α, and CD4+ cells in blood are captured at submicron resolution through the thickening epidermis and opaque scales during the development of psoriasis in vivo. Our data suggest IL-23 recruits CD4+ cells to release IL-17 in blood that further leaks out in the psoriatic skin area. This optical system enables noninvasive and real-time assessment of immune molecules and cells in vivo, providing good potential for medical researches on psoriasis.

Impact of Obesity on the IL-6 Immune Marker and Th17 Immune Cells in C57BL/6 Mice Models with Imiquimod-Induced Psoriasis

Obese psoriatic patients experience higher disease severity and exhibit poorer treatment responses and clinical outcomes. It has been proposed that proinflammatory cytokines produced by adipose tissue exacerbate psoriasis; however, the role of obesity in psoriasis remains unclear. This study aimed to elucidate the role of obesity in the pathogenesis of psoriasis, focusing on immunological changes. To induce obesity, mice were fed a high-fat diet for 20 weeks. We then applied imiquimod to the skin on a mouse’s back for seven consecutive days to induce psoriasis and scored lesion severity every day for seven days. Cytokine levels in serum and the Th17 cell population in the spleen and draining lymph nodes were studied to identify immunological differences. The clinical severity was more remarkable, and histologically the epidermis was also significantly thicker in the obese group. Increased levels of IL-6 and TNF-α were observed in serum after psoriasis. They were elevated to a greater degree, with greater expansion of the functional Th17 cell population in the obese group. It is concluded that obesity could exacerbate psoriasis through mechanisms that involve elevated proinflammatory cytokine secretion and an expanded Th17 cell population.

Literature Overview of the Relation Between Psoriasis and Alzheimer

The most common type of dementia disease is Alzheimer, which placing a heavy burden on the healthcare system all over the world. At the same time, psoriasis is also one of the most common health problems, as a skin disease. Alzheimer's disease (AD) is more often in patients with psoriasis than in the general people. Several evidence has proved the relation between AD and psoriasis through immune-mediated pathophysiologic processes. This review aims to summary the potential relation between AD and psoriasis, and provide suggestions based on the relationship at the same time. Neurologists, dermatologists should pay attention to the relationship between Alzheimer's disease and psoriasis. Dermatology and neurology need referral each other when it is necessary.

Histone deacetylase inhibitors as a potential new treatment for psoriatic disease and other inflammatory conditions

Collectively known as psoriatic disease, psoriasis and psoriatic arthritis (PsA) are immune-mediated inflammatory diseases in which patients present with cutaneous and musculoskeletal inflammation. Affecting roughly 2-3% of the world's total population, there remains unmet therapeutic needs in both psoriasis and PsA despite the availability of current immunomodulatory treatments. As a result, patients with psoriatic disease often experience reduced quality of life. Recently, a class of small molecules, commonly investigated as anti-cancer agents, called histone deacetylase (HDAC) inhibitors, have been proposed as a new promising anti-inflammatory treatment for immune- and inflammatory-related diseases. In inflammatory diseases, current evidence is derived from studies on diseases like rheumatoid arthritis (RA) and systematic lupus erythematosus (SLE), and while there are some reports studying psoriasis, data on PsA patients are not yet available. In this review, we provide a brief overview of psoriatic disease, psoriasis, and PsA, as well as HDACs, and discuss the rationale behind the potential use of HDAC inhibitors in the management of persistent inflammation to suggest its possible use in psoriatic disease.

Management of Infections in Psoriatic Patients Treated with Systemic Therapies: A Lesson from the Immunopathogenesis of Psoriasis

Modern treatments continue to be developed based on identifying targets within the innate and adaptive immune pathways associated with psoriasis. Whilst there is a sound biologic rationale for increased risk of infection following treatment with immunomodulators, the clinical evidence is confounded by these agents being used in patients affected with several comorbidities. In an era characterized by an ever greater and growing risk of infections, it is necessary to always be updated on this risk. In this mini-review, we will discuss recent updates in psoriasis immunopathogenesis as a rationale for systemic therapy, outline the risk of infections linked to the disease itself and systemic therapy as well, and provide an overview of the prevention and management of infections.

Subacute exposure to bisphenol F diglycidyl-ether induces chronic dermatitis characterized by psoriasis-like skin inflammation in mice

Bisphenol F diglycidyl ether (BFDGE) is widely used in the synthesis process of plastic products. While exposure to bisphenol A diglycidyl ether (BADGE), which has a similar structure to BFDGE and which is used for the same purpose, has been reported to cause health risks, there is still little information on BFDGE. Because it is estimated that the industrial workers are exposed to large amounts of BFDGE, the health risks associated with BFDGE exposure need to be clarified. We investigated the toxicity of cutaneous exposure to BFDGE using an in vitro evaluation system and a mouse exposure model. The tumorigenic potential of BFDGE was confirmed by the Bhas 42 cell transformation assay, which showed that BFDGE has both promoter and initiator activity, in vitro. A single dermal application of BFDGE was associated with minor contact hypersensitivity symptoms. In contrast, repeated dermal exposure to BFDGE for 2 weeks induced persistent acute inflammation with features similar to inflammation in human psoriasis. This is the first report evaluating the toxicity of BFDGE in animals, and we showed that BFDGE carries a health risk of inducing skin dermatitis similar to that in human psoriasis in an exposure period-dependent manner.

Nanoscale Topical Pharmacotherapy in Management of Psoriasis: Contemporary Research and Scope

Psoriasis is a typical dermal condition that has been anticipated since prehistoric times when it was mistakenly implicit in being a variant of leprosy. It is an atypical organ-specific autoimmune disorder, which is triggered by the activation of T-cells and/or B-cells. Until now, the pathophysiology of this disease is not completely explicated and still, many research investigations are ongoing. Different approaches have been investigated to treat this dreadful skin disease using various anti-psoriatic drugs of different modes of action through smart drug-delivery systems. Nevertheless, there is no ideal therapy for a complete cure of psoriasis owing to the dearth of an ideal drug-delivery system for anti-psoriatic drugs. The conventional pharmacotherapy approaches for the treatment of psoriasis demand various classes of anti-psoriatic drugs with optimum benefit/risk ratio and insignificant untoward effects. The advancement in nanoscale drug delivery had a great impact on the establishment of a nanomedicine-based therapy for better management of psoriasis in recent times. Nanodrug carriers are exploited to design and develop nanomedicine-based therapy for psoriasis. It has a promising future in the improvement of the therapeutic efficacy of conventional anti-psoriatic drugs. The present manuscript aims to discuss the pathophysiology, conventional pharmacotherapy, and contemporary research in the area of nanoscale topical drug delivery systems for better management of psoriasis including the significance of targeted pharmacotherapy in psoriasis.

Impact of Chronic Inflammation in Psoriasis on Bone Metabolism

Psoriasis is a chronic inflammatory disease of the skin and joints associated with several comorbidities such as arthritis, diabetes mellitus and metabolic syndrome, including obesity, hypertension and dyslipidaemia, Crohn's disease, uveitis and psychiatric and psychological diseases. Psoriasis has been described as an independent risk factor for cardiovascular diseases and thus patients with psoriasis should be monitored for the development of cardiovascular disease or metabolic syndrome. However, there is mounting evidence that psoriasis also affects the development of osteoporosis, an important metabolic disease with enormous clinical and socioeconomic impact. At present, there are still controversial opinions about the role of psoriasis in osteoporosis. A more in depth analysis of this phenomenon is of great importance for affected patients since, until now, bone metabolism is not routinely examined in psoriatic patients, which might have important long-term consequences for patients and the health system. In the present review, we summarize current knowledge on the impact of psoriatic inflammation on bone metabolism and osteoporosis.

ILF2 Contributes to Hyperproliferation of Keratinocytes and Skin Inflammation in a KLHDC7B-DT-Dependent Manner in Psoriasis

Background: The extensive involvement of interleukin enhancer binding factor 2 (ILF2) in RNA stability and the inflammatory response is well documented. Aberrant long noncoding RNA (lncRNA) expression contributes to the pathogenesis of psoriasis. However, little is known about the role of ILF2 in psoriasis. Objective: To investigate the role of ILF2 and KLHDC7B-DT in psoriasis. Methods: LncRNA expression in psoriatic tissues was measured by lncRNA microarray and qRT-PCR. Normal human epidermal keratinocytes (NHEKs), HaCaT cells, and Ker-CT cells stimulated with M5 (IL-17A, IL-22, IL-1α, oncostatin M, and TNF-α) were used to establish a psoriasis model in vitro. Fluorescence in situ hybridization was used to detect the distribution of KLHDC7B-DT and ILF2 in keratinocytes. The proliferative effects of KLHDC7B-DT and ILF2 on keratinocytes were demonstrated by EdU assay and flow cytometry. ELISA was used to detect the secretion levels of cytokines. RNA pull-down and RNA immunoprecipitation (RIP) were used to detect the direct binding of KLHDC7B-DT with ILF2. Western blotting was used to detect the proteins related to STAT3/JNK signalling pathways. Results: ILF2 and KLHDC7B-DT were significantly overexpressed in psoriatic tissues and M5-induced keratinocytes. KLHDC7B-DT promoted the proliferation of keratinocytes and induced the secretion of IL-6 and IL-8. KLHDC7B-DT could directly bind to ILF2 and activate the STAT3 and JNK signalling pathways. KLHDC7B-DT expression was regulated by ILF2. M5-induced proliferation and inflammatory cytokine secretion in keratinocytes was inhibited after ILF2 knockdown. Furthermore, we found that ILF2 promoted keratinocyte proliferation and the inflammatory response in a KLHDC7B-DT-dependent manner. Conclusions: ILF2 and KLHDC7B-DT are involved in the hyperproliferation of keratinocytes and skin inflammation in psoriasis. In addition, ILF2 functions in a KLHDC7B-DT-dependent manner.

Alpha-Linolenic Acid Modulates T Cell Incorporation in a 3D Tissue-Engineered Psoriatic Skin Model

Psoriasis is an autoimmune skin disease with an increased number of leukocytes infiltrating the dermal and epidermal compartments compared with normal skin. N-3 polyunsaturated fatty acids (n-3 PUFAs) are frequently used in the clinic in order to attenuate the symptoms of psoriasis. For psoriatic patients, a supplementation of the diet with alpha-linolenic acid (ALA) reduces the activation of T cell signaling pathways, leading to a significant reduction in inflammatory cytokine secretion. However, the precise mechanism of action of n-3 PUFAs in psoriasis is still not understood. In the present study, we elucidated the bioaction of ALA on the adaptive immune component of psoriasis by using a psoriatic skin model produced with the addition of activated T cells. Healthy and psoriatic skin substitutes were produced according to the self-assembly method, using culture media supplemented with 10 μM of ALA. T cells were isolated from blood samples using a negative selection isolation method. ALA supplementation regulated the hyperproliferation and abnormal cell differentiation of psoriatic keratinocytes stimulated by T cells. Additionally, the exogenous ALA was correctly incorporated into the phospholipids of keratinocytes, which resulted in increased levels of ALA, eicosapentaenoic acid (EPA) and n-3 docosapentaenoic acid (n-3 DPA). The infiltration of T cells into the epidermis was reduced when ALA was added to the culture medium, and significant decreases in the levels of inflammatory cytokines and chemokines such as CXCL1, interleukin-6 (IL-6) and interleukin-8 (IL-8) were consequently measured in psoriatic substitutes supplemented with this n-3 PUFA. Altogether, our results showed that in this psoriatic skin model enriched with T cells, ALA exerted its beneficial effect by decreasing the quantities of inflammatory mediators released by T cells.

Nanotechnology-based medicinal products and patents: a promising way to treat psoriasis

Psoriasis is an autoimmune skin disorder that is characterised by chronic inflammation and erythematous scaly patches. It has a significant impact on the patient's quality of life and can cause psychological stress. There are several aspects which cause psoriasis for instance, environmental issues, immune disorders, bacterial infections, and genetic issues. Plentiful therapeutic means or treatments are accessible, but not any of them can completely and effectively cure psoriasis without hindering patient compliance. Hence, it becomes challenging to discover a new drug moiety or any drug delivery method to cure psoriasis. Conventional treatment of psoriasis involves anti-inflammatory agents, immune suppressants, phototherapy, and biologic treatment, those were given in different forms such as topical, oral, or systemic formulations, but these all were unsuccessful to accomplish complete reduction of psoriasis as well as causing adverse side effects. In terms of dose frequency, doses, efficacy, and side effects, nanotechnology-based new formulations are the most promising prospects for addressing the challenges and limits associated with present psoriasis formulations. Hence, our major goal of this review is to present various advanced nanotechnological approaches for effective topical treatment of psoriasis. In short, nano-formulations continue to be formed as very promising modality in the treatment of psoriasis as they suggest improved penetration, targeted delivery, increased safety, and efficacy.

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.

The hair follicle-psoriasis axis: Shared regulatory mechanisms and therapeutic targets

It has long been known that there is a special affinity of psoriasis for the scalp: Here, it occurs most frequently, lesions terminate sharply in frontal skin beyond the hair line and are difficult to treat. Yet, surprisingly, scalp psoriasis only rarely causes alopecia, even though the pilosebaceous unit clearly is affected. Here, we systematically explore the peculiar, insufficiently investigated connection between psoriasis and growing (anagen) terminal scalp hair follicles (HFs), with emphasis on shared regulatory mechanism and therapeutic targets. Interestingly, several drugs and stressors that can trigger/aggravate psoriasis can inhibit hair growth (e.g. beta-blockers, chloroquine, carbamazepine, interferon-alpha, perceived stress). Instead, several anti-psoriatic agents can stimulate hair growth (e.g. cyclosporine, glucocorticoids, dithranol, UV irradiation), while skin/HF trauma (Köbner phenomenon/depilation) favours the development of psoriatic lesions and induces anagen in "quiescent" (telogen) HFs. On this basis, we propose two interconnected working models: (a) the existence of a bidirectional "hair follicle-psoriasis axis," along which keratinocytes of anagen scalp HFs secrete signals that favour the development and maintenance of psoriatic scalp lesions and respond to signals from these lesions, and (b) that anagen induction and psoriatic lesions share molecular "switch-on" mechanisms, which invite pharmacological targeting, once identified. Therefore, we advocate a novel, cross-fertilizing and integrative approach to psoriasis and hair research that systematically characterizes the "HF-psoriasis axis," focused on identification and therapeutic targeting of selected, shared signalling pathways in the future management of both, psoriasis and hair growth disorders.

Impact of Streptococcus pyogenes infection in susceptibility to psoriasis: A systematic review and meta-analysis

BACKGROUND

Psoriasis is one of the most common chronic systemic diseases, mainly appearing as lesions on the skin and joints, and is associated with a high mortality due to a lack of standard treatment. The exact mechanism of this disease is not fully understood, but the inflammatory response and dysregulation of the immune system are the most important molecular processes that trigger this disease. The skin microflora is one of the main factors involved in inducing, maturing, and dysregulating the immune system, which may underly the development of psoriasis.

AIM

To determine the impact of Streptococcus pyogenes (S. pyogenes) infection and susceptibility to psoriasis using available case-control studies.

METHODS

In this study, we conducted a comprehensive literature search using PubMed, Scopus, Web of science, and Google scholar databases to obtain all available relevant studies on the association between S. pyogenes and psoriasis. We pooled the data using Comprehensive Meta-analysis software to investigate the role of S. pyogenes infection in the development of psoriasis. The probable connection between S. pyogenes and susceptibility to psoriasis was assessed using the odds ratio (OR) with corresponding 95% confidence intervals (CIs).

RESULTS

Data from 781 cases were evaluated in this study. Our results showed that the rate of infection with S. pyogenes in psoriatic patients and healthy individuals was 33.4% (95%CI: 27.8-39.6) and 16.2% (95%CI: 9.7-25.9), respectively. S. pyogenes infection significantly increased the risk of psoriasis (OR: 6.58; 95%CI: 3.64-11.87; P = 0.001).

CONCLUSION

S. pyogenes infection can significantly increase the risk of psoriasis. Thus, infection with S. pyogenes is a risk factor for the initiation and development of psoriatic events.

Incidence of Skin Cancer in Patients With Chronic Inflammatory Cutaneous Diseases on Targeted Therapies: A Systematic Review and Meta-Analysis of Observational Studies

Cancer is one of the several comorbidities that have been linked with chronic cutaneous inflammatory diseases namely psoriasis/psoriatic arthritis and hidradenitis suppurativa. Although the chronic inflammatory state, typical of the diseases, may induce pro-tumorigenic effects, the debate whether or not the drugs currently used in clinical practice do in facts increase a patient's risk of malignancy remains largely unsolved. The therapeutic armamentarium has been greatly enhanced at least in the last two decades with the advent of biologics, a heterogeneous group of laboratory-engineered agents with more in the pipeline, and other targeted small molecules. Among the organ systems, skin results as one of the most commonly affected, non-melanoma skin cancers being the main drug-induced manifestations as side effect in course of these treatments. The objective of the study is to systematically review the cutaneous malignancy risk of the newer therapies through an overview of meta-analyses and observational studies on the topic.

Studies on the anti-psoriasis effects and its mechanism of a dual JAK2/FLT3 inhibitor flonoltinib maleate

Psoriasis is a chronic, inflammatory autoimmune disease mediated by T cells, and characterized with abnormal proliferation and differentiation of keratinocytes, and inflammatory infiltration. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway has been identified to play essential roles in mediating various of biological processes, and is closely related to autoimmune diseases. Dendritic cells (DCs) are important antigen presenting cells and play an important regulatory role in T cells. The proliferation, differentiation and function of DCs are regulated by JAK and FMS-like tyrosine kinase 3 (FLT3) signal pathways. Flonoltinib maleate (FM), a high selectivity dual JAK2/FLT3 inhibitor with IC50 values of 0.8 nM and 15 nM for JAK2 and FLT3, respectively, was developed by our laboratory. Moreover, FM was a potent JAK2 inhibitor with 863-fold and 696-fold selectivity over JAK1 and JAK3, respectively. In this study, the anti-psoriasis activity of FM was evaluated both in vitro and in vivo. FM effectively inhibited the proliferation of HaCaT, the inflammatory keratinocyte induced by M5 and markedly suppressed the generation and differentiation of DCs from bone marrow (BM), and inhibited the expression of FLT3 in DCs in vitro. FM effectively inhibited the ear thickening and improved the pathological changes of the ear in interleukin (IL)-23-induced psoriasis-like acanthosis mouse model. Further in keratin 14-vascular endothelial growth factor (K14-VEGF) transgenic homozygous mice model, FM could obviously improve the psoriatic symptom and pathological changes, significantly inhibit the generations of Th1 and Th17 cells in the spleen, and the accumulations of DCs in the ears. FM could also significantly reduce the expression of various inflammatory factors both in C57BL/6 and K14-VEGF mice ears, and the serum of K14-VEGF mice. Mechanism revealed that FM effectively suppressed the phosphorylation of JAK2, STAT3 and STAT5 in inflammatory keratinocytes and the mice ears of C57BL/6 and K14-VEGF, as well as the phosphorylation of FLT3 in K14-VEGF mice ears. In conclusion, FM plays an excellent anti-psoriasis activity, including inhibiting keratinocyte proliferation and regulating inflammatory response through inhibiting JAK2 and FLT3 signaling pathway.

Circ_0061012 contributes to IL-22-induced proliferation, migration and invasion in keratinocytes through miR-194-5p/GAB1 axis in psoriasis

Psoriasis is a chronic inflammation-associated skin disorder featured by excessive proliferation and abnormal differentiation of keratinocytes. Here, we intended to investigate the role of circular RNA 0061012 (circ_0061012) in psoriasis progression. The expression of circ_0061012, SLMO2-ATP5E readthrough (SLMO2-ATP5E) messenger RNA (mRNA), microRNA-194-5p (miR-194-5p) and GRB2 associated binding protein 1 (GAB1) mRNA was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation and metastasis were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and transwell assays. Western blot assay was used to measure the protein levels of Ki67, matrix metallopeptidase 9 (MMP9) and GAB1. Dual-luciferase reporter assay and RNA immune co-precipitation (RIP) assay were used to verify the interaction between miR-194-5p and circ_0061012 or GAB1. Circ_0061012 abundance was significantly enhanced in lesional skin samples from psoriasis patients than that in normal skin specimens from healthy volunteers. Interleukin-22 (IL-22) treatment increased the expression of circ_0061012 in a dose-dependent manner. Circ_0061012 silencing alleviated IL-22-induced promoting effects in the proliferation, migration and invasion of HaCaT cells. Circ_0061012 interacted with miR-194-5p, and miR-194-5p knockdown counteracted circ_0061012 silencing-mediated influences in IL-22-induced HaCaT cells. GAB1 was a target of miR-194-5p in HaCaT cells, and miR-194-5p hampered proliferation and metastasis which were induced by IL-22 partly through targeting GAB1. Circ_0061012 elevated the expression of GAB1 through sponging miR-194-5p in HaCaT cells. Circ_0061012 accelerated IL-22-induced proliferation and metastasis in HaCaT cells through enhancing GAB1 expression via sponging miR-194-5p in psoriasis.

Could basement membrane alterations, resembling micro-wounds at the dermo-epidermal junction in psoriatic non-lesional skin, make the skin susceptible to lesion formation?

Current data suggest that tissue microenvironment control immune functions. Therefore, understanding the tissue environment in which immune activation occurs will enhance our capability to interfere with abnormal immune pathology. Here, we argue that studying the constitutively abnormal functions of clinically uninvolved psoriatic skin in patients with plaque type psoriasis is very important to better understand psoriasis pathobiology, because non-lesional skin provides the tissue environment in which the psoriatic lesion develops. A key question in psoriasis is what initiates the abnormal, uncontrolled immune activation in the first place and the answer may lie in the skin. In light of this concept, we summarize abnormalities at the dermal-epidermal junction region which shows a special "non-healing-like" micro-wound phenotype in the psoriatic non-lesional skin that may act as a crucial susceptibility factor in the development of the disease.

Is there any association between psoriasis, psoriatic arthritis and thyroid autoimmunity?

BACKGROUND

Autoimmune diseases share a significant part of their genetic background and tend to coexist in the same patient. Some studies have investigated the possible association between autoimmune thyroiditis and psoriasis or psoriatic arthritis (PsA), with conflicting results. This study aimed to investigate the prevalence of autoimmune thyroiditis in psoriatic patients with (PsA) or without (PsC) joint involvement.

METHODS

208 patients with psoriasis and/or PsA were recruited. These patients were divided into two groups: psoriasis patients (without PsA) (PsC group: 100 patients; mean age of 50.1 ± 11.7 years) and subjects with psoriasis and psoriatic arthritis (PsA group: 108 subjects: mean age of 39.8 ± 10.8 years). Assessment of psoriasis severity was conducted using the Psoriasis Area and Severity Index (PASI) score. The diagnosis of psoriatic arthritis was made according to CASPAR criteria. All patients had thyroid evaluation through evaluation of thyroid function, thyroperoxidase antibodies and thyroid ultrasound examination.

RESULTS

A statistically significant difference was found between the prevalence of autoimmune thyroiditis in the PsA group than the PsC group (25.9 vs 9.0 %; P = 0.018) with higher trends to hypothyroidism in the PsA group compared to the PsC group (13.9% vs 2.0%, P = 0.0018).

CONCLUSIONS

The higher prevalence of autoimmune thyroiditis in the PsA group may be due to an immune dysfunction pathway in patients with psoriatic arthritis with a higher risk to develop other autoimmune diseases. This evidence confirms that psoriatic arthritis is an autoimmune disease with an overactive immune system that can involve multiple organs. Thyroid function evaluation should be part of the clinical and laboratory examination of patients with psoriatic arthritis.

Transcriptome Profiling Analyses in Psoriasis: A Dynamic Contribution of Keratinocytes to the Pathogenesis

Psoriasis is an immune-mediated inflammatory skin disease with a complex etiology involving environmental and genetic factors. A better insight into related genomic alteration helps design precise therapies leading to better treatment outcome. Gene expression in psoriasis can provide relevant information about the altered expression of mRNA transcripts, thus giving new insights into the disease onset. Techniques for transcriptome analyses, such as microarray and RNA sequencing (RNA-seq), are relevant tools for the discovery of new biomarkers as well as new therapeutic targets. This review summarizes the findings related to the contribution of keratinocytes in the pathogenesis of psoriasis by an in-depth review of studies that have examined psoriatic transcriptomes in the past years. It also provides valuable information on reconstructed 3D psoriatic skin models using cells isolated from psoriatic patients for transcriptomic studies.

Periodontitis in patients with psoriasis: A systematic review and meta-analysis

Objective

The present study aimed to summarize and update the evidence regarding the association between periodontitis and psoriasis.

Methods

The present systematic review was conducted under the guidelines of Transparent Reporting of Systematic Reviews and Meta‐Analyses (PRISMA) and was recorded in the PROSPERO database, under registration number CRD42017063799. Three databases (MEDLINE, Embase, and Cochrane Library) were searched up to March 2020. Case–control or cohort studies assessing the association between periodontitis and psoriasis were identified. Quantitative synthesis was conducted with meta‐analysis.

Results

A total of 13 studies (11 case–control and two cohort studies) assessing the association between periodontitis and psoriasis were included. Of these 13 articles, 9 showed the prevalence of periodontitis or psoriasis. Therefore, meta‐analyses were conducted with data retrieved from the nine studies included. Pooled effect estimate for nine studies showed that patients with periodontitis associated with a higher risk of psoriasis with a pooled OR of 2.87 (95% CI, 1.75–4.69).

Conclusions

This systematic review demonstrated a positive association between periodontitis and psoriasis; however, a causal relationship cannot be established. Due to the weak evidence, caution should be taken when interpreting the results regarding periodontal parameters. Well‐designed prospective studies are necessary to evaluate interactions between both diseases.

The importance of immunity in the development of reliable animal models for psoriasis and atopic dermatitis

Psoriasis (PS) and atopic dermatitis (AD) are common inflammatory skin diseases characterized by an imbalance in specific T-cell subsets, resulting in a specific cytokine profile in patients. Obtaining models closely resembling both pathologies along with a relevant clinical impact is crucial for the development of new therapies because of the high prevalence of these diseases. Single-gene mouse models developed until now do not fully reflect the complexity of these disorders, in part not only because of inherent differences between mice and humans but also because of the multifactorial nature of these pathologies. The skin-humanized mouse model developed by our group, based on a tissue engineering approach, has been used to test therapeutic strategies, although this methodology is still technically challenging and not widely available. The skin-humanized mouse models for PS and AD reproduce human skin phenotypes, providing valuable tools for drug development and testing in the preclinical setting. The tissue engineering approach allows the development of personalized medicine, covering the broad genotypic spectrum of these pathologies. This review highlights the main differences between available murine models focusing on the tissue-specific immunity of PS and AD. We discuss their contribution to unravel the complex pathophysiology of these diseases and to translate this knowledge into more accurate therapies.

miR-183-3p suppresses proliferation and migration of keratinocyte in psoriasis by inhibiting GAB1

Background

MicroRNAs (miRNAs) target genes involved in the hyperproliferation of keratinocytes or immune dysfunction of psoriasis. This study prospectively determined the involvement of miR-183-3p in the pathogenesis of psoriasis.

Methods

Differentially expressed miR-183-3p between psoriatic lesional and non-lesional skin were determined by quantitative RT-PCR and in situ hybridization (ISH). CCK8 and wound healing assays were performed to assess cell viability and migration of human keratinocyte cell line (HaCaT). The target of miR-183-3p was validated by luciferase activity assay.

Results

Lower miR-183-3p expression was observed in psoriatic lesional skin compared to psoriatic non-lesional skin. MiR-183-3p over-expression inhibited the viability and migration of HaCaT cells, while inhibition of miR-183-3p promoted the viability and migration of HaCaT cells. Moreover, miR-183-3p could bind to the 3′ UTR of GAB1 (growth factor receptor binding 2-associated binding protein 1) and decrease the mRNA and protein expression of GAB1 in HaCaT cells. In addition, higher GAB1 expression was observed in psoriatic lesional skin than psoriatic non-lesional skin.

Conclusion

MiR-183-3p exhibited inhibition property in the proliferation and migration of HaCaT cells via down-regulation of GAB1, suggesting the potential therapeutic strategy for psoriasis.

Activated Platelets Induce Endothelial Cell Inflammatory Response in Psoriasis via COX-1

OBJECTIVE

Patients with psoriasis have impaired vascular health and increased cardiovascular disease (CVD). Platelets are key players in the pathogenesis of vascular dysfunction in cardiovascular disease and represent therapeutic targets in cardiovascular prevention. The object of this study was to define the platelet phenotype and effector cell properties on vascular health in psoriasis and evaluate whether aspirin modulates the platelet-induced phenotype. Approach and Results: Platelets from psoriasis patients (n=45) exhibited increased platelet activation (relative to age- and gender-matched controls, n=18), which correlated with psoriasis skin severity. Isolated platelets from psoriasis patients demonstrated a 2- to 3-fold (P<0.01) increased adhesion to human aortic endothelial cells and induced proinflammatory transcriptional changes, including upregulation of IL 8 (interleukin 8), IL1β, and Cox (cyclooxygenase)-2 Platelet RNA sequencing revealed an interferon signature and elevated expression of COX-1, which correlated with psoriasis disease severity (r=0.83, P=0.01). In a randomized trial of patients with psoriasis, 2 weeks of 81 mg low-dose aspirin, a COX-1 inhibitor, reduced serum thromboxane (Tx) B2 and reduced brachial vein endothelial proinflammatory transcript expression >70% compared with the no-treatment group (P<0.01). Improvement in brachial vein endothelial cell inflammation significantly correlated with change in serum TxB2 (r=0.48, P=0.02).

CONCLUSIONS

In patients with psoriasis, platelets are activated and induce endothelial cell inflammation. Low-dose aspirin improved endothelial cell health in psoriasis via platelet COX-1 inhibition. These data demonstrate a previously unappreciated role of platelets in psoriasis and endothelial cell inflammation and suggests that aspirin may be effective in improving vascular health in patients with psoriasis. Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT03228017.

Corticoid-like anti-inflammatory effect of Vochysia bifalcata Warm.: Preclinical evidence of efficacy and safety

ETHNOPHARMACOLOGICAL RELEVANCE

Vochysia bifalcata is a Brazilian native tree commonly used for economic purpose in the reforestation and in the manufacture of products. However, the potential usage of other parts of the plant is usually wasted. Besides, other species of Vochysia are well known for its anti-inflammatory action.

AIM OF THE STUDY

In this study we evaluate the possible anti-inflammatory activity of the hydroethanolic extract from the leaves of V. bifalcata in models of mice skin inflammation.

MATERIALS AND METHODS

Effects of V. bifalcata were evaluated in croton oil-induced acute and chronic skin inflammation. The role of glucocorticoid receptors in the extract effect was assessed by using a glucocorticoid receptor antagonist and by a specific binding assay. Possible adverse effects were evaluated after multiple treatments with the extract in a skin atrophy model.

RESULTS

Topical application of V. bifalcata reduced ear edema formation, cell infiltration and interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels. In the chronic model, besides edema formation and cell infiltration, the extract inhibited epidermal hyperproliferation and Proliferating Cell Nuclear Antigen expression. V. bifalcata seems to act by biding to corticoid receptors, however it did not induce corticoid related undesirable effects.

CONCLUSION

Hydroethanolic extract from leaves of V. bifalcata could be an interesting tool in the search for new anti-inflammatory and antiproliferative agents for the treatment of skin disorders.

Psoriasis: Obesity and Fatty Acids

Psoriasis is chronic inflammatory skin disease affecting skin, joints, cardiovascular system, brain, and metabolism. The pathogenesis of psoriasis is mediated by a complex interplay between the immune system, inflammatory mediators of different pathways, e.g., TNF-alpha and the IL-23/IL-17 pathways, psoriasis-associated susceptibility loci, autoantigens, and multiple environmental factors. Psoriasis is triggered by the combination of genetic and environmental factors. A novel environmental risk factor with rising importance is obesity. Several studies proved that obesity is an independent risk factor for the onset and severity of psoriasis. Due to the dramatic increase of obesity worldwide this minireview focuses on obesity as a major environmental risk factor for psoriasis and the mechanisms of obesity-mediated exacerbation of psoriasis.

Inhibition of NLRP3 inflammasome-mediated pyroptosis in macrophage by cycloastragenol contributes to amelioration of imiquimod-induced psoriasis-like skin inflammation in mice

Psoriasis is a common chronic inflammatory skin disease, and the infiltrated macrophages in psoriatic skin lesions play a key role in the progression of this uncontrolled cutaneous inflammation. However, the current therapeutic strategies for patients with psoriasis are not satisfactory. Here, we report that cycloastragenol (CAG), a natural active small compound isolated from Astragalus membranaceus, significantly ameliorated imiquimod (IMQ)-induced psoriasiform dermatitis in mice by targeting proinflammatory macrophages. CAG significantly reduced the clinical scores, decreased the epidermal thickness, and ameliorated the deteriorating histopathology observed in IMQ-induced mice. CAG treatment specifically reduced the dermal infiltration of macrophages, rather than of dendritic cells, neutrophils, or T lymphocytes, into psoriatic skin. CAG dose-dependently decreased the level of proinflammatory cytokines, including IL-1β, TNF-α and IL-6, in murine psoriatic skin and serum, as well as in IMQ-stimulated, bone-marrow-derived macrophages. When compared to the control group, CAG significantly decreased IMQ-triggered NLRP3 inflammasome activation and gasdermin D-mediated cell pyroptosis in these proinflammatory macrophages. CAG also suppressed the assembly of the NLRP3 inflammasome complex. Taken together, the results show that CAG selectively modulates macrophage function by inhibiting NLRP3 inflammasome-mediated pyroptosis to ameliorate IMQ-induced psoriasis-like skin inflammation in mice. Our findings also identify an effective drug candidate for the treatment of psoriasis.

Betulinic acid suppresses Th17 response and ameliorates psoriasis-like murine skin inflammation

Psoriasis is a common inflammatory skin disease. Current treatment for psoriasis relies on conventional immunosuppressive agents. However, long-term treatment with global immunosuppression may cause various side effects. Thus, it is compelling to seek alternative drugs for treating psoriasis with potentially less side effects. Betulinic acid (BA) is a naturally occurring pentacyclic triterpene, an ingredient that originally exists in natural plants and lacks systemic toxicity. BA can regulate immunity with anti-fibrotic, anti-inflammatory and antioxidant properties. However, it's unknown whether BA has a therapeutic effect on psoriasis. The objectives of this study were to investigate whether BA attenuates psoriatic skin inflammation and to identify its mechanisms of action. A murine model of imiquimod-induced psoriasis was utilized to evaluate skin lesion while flow cytometry, immunohistochemistry, quantitative RT-PCR and Western blotting analyses were performed for immunoassays. We found that BA treatment alleviated psoriatic symptoms and inflammatory skin lesion. BA lowered the PASI scores, decreased epidermal thickness and reduced T cell infiltration in the skin lesion. Moreover, BA reduced the frequency of IL-17A-expressing CD4⁺ and γδ T cells in psoriatic mice, but did not alter CD4⁺FoxP3⁺ Treg frequency. BA also reduced IL-17A production but increased anti-inflammatory cytokine IL-10 level in serum of the psoriatic mice. Furthermore, BA inhibited gene expression of pro-inflammatory mediators in skin lesions, including RORγt, IL-17A, IL-6 and TNFα. Importantly, it suppressed NFκB signaling in the skin lesion. Finally, BA inhibited T cell proliferation and IL-17A production by CD4⁺ T-Cells in vitro. Thus, BA attenuates psoriasis and inhibits Th17 development.

Inflammasome Signaling and Impaired Vascular Health in Psoriasis

Objective- Psoriasis is an inflammatory skin disease which heightens the risk of cardiovascular disease. This study directly investigated vascular endothelial health and systemically altered pathways in psoriasis and matched controls. Approach and Results- Twenty patients (mean age, 40 years; 50% male) with active psoriasis and 10 age-, sex-matched controls were recruited. To investigate systemically alerted pathways, a deep sequencing omics approach was applied, including unbiased blood transcriptomic and targeted proteomic analysis. Vascular endothelial health was assessed by transcriptomic profiling of endothelial cells obtained from the brachial veins of recruited participants. Blood transcriptomic profiling identified inflammasome signaling as the highest differentially expressed canonical pathway ( Z score 1.6; P=1×10^-7) including upregulation of CASP5 and interleukin ( IL) -1β. Proteomic panels revealed IL-6 as a top differentially expressed cytokine in psoriasis with pathway analysis highlighting IL-1β ( Z score 3.7; P=1.02×10^-23) as an upstream activator of the observed upregulated proteins. Direct profiling of harvested brachial vein endothelial cells demonstrated inflammatory transcript (eg, IL-1β, CXCL10, VCAM-1, IL-8, CXCL1, Lymphotoxin beta, ICAM-1, COX-2, and CCL3) upregulation between psoriasis versus controls. A linear relationship was seen between differentially expressed endothelial inflammatory transcripts and psoriasis disease severity. IL-6 levels correlated with inflammatory endothelial cell transcripts and whole blood inflammasome-associated transcripts, including CASP5 and IL-1β. Conclusions- An unbiased sequencing approach demonstrated the inflammasome as the most differentially altered pathway in psoriasis versus controls. Inflammasome signaling correlated with psoriasis disease severity, circulating IL-6, and proinflammatory endothelial transcripts. These findings help better explain the heightened risk of cardiovascular disease in psoriasis. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03228017.

Ghrelin protects against contact dermatitis and psoriasiform skin inflammation by antagonizing TNF-α/NF-κB signaling pathways

Contact dermatitis and psoriasis are skin disorders caused by immune dysregulation, yet much remains unknown about their underlying mechanisms. Ghrelin, a recently discovered novel peptide and potential endogenous anti-inflammatory factor expressed in the epidermis, is involved in skin repair and disease. In this study, we investigated the expression pattern and therapeutic effect of ghrelin in both contact dermatitis and psoriasis mouse models induced by oxazolone (OXA) and imiquimod (IMQ), respectively, and in TNF-α-stimulated RAW264.7 macrophages, NHEKs and skin fibroblasts. Ghrelin expression was reduced in both the OXA-induced contact dermatitis and IMQ-induced psoriasis mouse models. Furthermore, treatment with ghrelin attenuated skin inflammation in both the contact dermatitis and psoriasis mouse models. Mice administered PBS after OXA- or IMQ-induced model generation exhibited typical skin inflammation, whereas ghrelin treatment in these mouse models substantially decreased the dermatitis phenotype. In addition, exogenous ghrelin attenuated the inflammatory reaction induced by TNF-α in RAW264.7 cells. Moreover, ghrelin administration limited activation of NF-κB signaling. In summary, ghrelin may represent a potential molecular target for the prevention and treatment of inflammatory skin diseases, including contact dermatitis and psoriasis.

Development of A New Delivery System Based on Drug-Loadable Electrospun Nanofibers for Psoriasis Treatment

Psoriasis is a chronic autoimmune systemic disease with an approximate incidence of 2% worldwide; it is commonly characterized by squamous lesions on the skin that present the typical pain, stinging, and bleeding associated with an inflammatory response. In this work, poly(methyl vinyl ether-alt-maleic ethyl monoester) (PMVEMA-ES) nanofibers have been designed as a delivery vehicle for three therapeutic agents with palliative properties for the symptoms of this disease (salicylic acid, methyl salicylate, and capsaicin). For such a task, the production of these nanofibers by means of the electrospinning technique has been optimized. Their morphology and size have been characterized by optical microscopy and scanning electron microscopy (SEM). By selecting the optimal conditions to achieve the smallest and most uniform nanofibers, approximate diameters of up to 800⁻900 nm were obtained. It was also determined that the therapeutic agents that were used were encapsulated with high efficiency. The analysis of their stability over time by GC-MS showed no significant losses of the encapsulated compounds 15 days after their preparation, except in the case of methyl salicylate. Likewise, it was demonstrated that the therapeutic compounds that were encapsulated conserved, and even improved, their capacity to activate the transient receptor potential cation channel 1 (TRPV1) channel, which has been associated with the formation of psoriatic lesions.

Expression and potential role of cellular retinol binding protein I in psoriasis

Psoriasis is a diffuse chronic skin disorder characterized from accelerated epidermal turnover and inflammatory cell infiltrate. Retinoids influence keratinocyte proliferation and differentiation as well as inflammatory response. Cellular retinol binding protein (CRBPI) regulates intracellular vitamin A bioavailability and contributes to maintain skin homeostasis. The aim of present study was to investigate the expression of CRBPI and its role in the pathogenesis of skin psoriasis. Immunohistochemistry revealed more diffuse and increased CRBPI expression in all epidermal layers of human psoriatic lesions except in the stratum corneum. An imiquimod-induced psoriatic-like model documented the increase of skin lesional area and severity index score as well as of the severity of microscopic features as parakeratosis, papillomatosis and spongiosis in CRBPI-knockout compared to wild-type mice, associated to the increased keratinocyte CK17 and Ki-67 expression and the reduction of CK1, CRABPII and RXRα. Gene array of imiquimod-induced psoriatic skin documented the greater up-regulation of EGF/PDGF-related genes and down-regulation of EGR1 and pro-inflammatory IL-related genes in CRBPI-knockout compared to wild-type mice. Finally, CRBPI transfection in HaCaT cells increased AKT and NF-κB-related genes and proteins and down-regulated IL-2, IL-6 and IL-8 pro-inflammatory signalling. Although not recognized as a psoriatic susceptibility gene in our cohort of patients, the present data strongly supported the potential role of CRBPI to sustain keratinocyte proliferation and differentiation and to counteract pro-inflammatory genes expression in psoriatic lesions.

Psoriasis and cardiovascular disease: the elusive link

Psoriasis, an autoimmune inflammatory disease, with its most common coexisting condition, psoriatic arthritis, seem to be more than just a local skin or joint disease, as evidence has accumulated over the years that it is associated with cardiovascular disease (CVD), which may confer an increased cardiovascular event and death rate. The data come mostly from observational studies and meta-analyses and indicate a potential pathogenetic link between these two systemic diseases, however definite proof of this detrimental relationship awaits further prospective studies. Newer anti-psoriatic biologic therapies seem to confer a cardiovascular benefit, but this needs future randomized controlled studies to confirm. All these intricate issues of a potential link between psoriasis and CVD are discussed and elaborated in this overview, in an attempt to shed further light on pivotal aspects of the association between psoriasis and CVD.

The Tissue-Engineered Human Psoriatic Skin Substitute: A Valuable In Vitro Model to Identify Genes with Altered Expression in Lesional Psoriasis

Psoriasis is a chronic inflammatory skin disease for which no cure has emerged. Its complex etiology requires the development of an in vitro model representative of the pathology. In this study, we exploited gene profiling analyses on microarray in order to characterize and further optimize the production of a human psoriatic skin model representative of this in vivo skin disease. Various skin substitutes were produced by tissue-engineering using biopsies from normal, healthy donors, or from lesional or non-lesional skin samples from patients with psoriasis, and their gene expression profiles were examined by DNA microarray. We demonstrated that more than 3540 and 1088 genes (two-fold change) were deregulated between healthy/lesional and lesional/non-lesional psoriatic substitutes, respectively. Moreover, several genes related to lipid metabolism, such as PLA2G4E and PLA2G4C, were identified as repressed in the lesional substitutes. In conclusion, gene profiling analyses identified a list of deregulated candidate genes associated with various metabolic pathways that may contribute to the progression of psoriasis.

Oxidized Low-Density Lipoprotein-Deteriorated Psoriasis Is Associated with the Upregulation of Lox-1 Receptor and Il-23 Expression In Vivo and In Vitro

Psoriasis is a chronic inflammatory skin disease. Even though scientists predict that abnormalities in lipid metabolism play an important role in the pathogenesis of psoriasis, the actual underlying mechanisms are still unclear. Therefore, understanding the possible relationship between mechanisms of the occurrence of psoriasis and dyslipidemia is an important issue that may lead to the development of effective therapies. Under this principle, we investigated the influences of hyperlipidemia in imiquimod (IMQ)-induced psoriasis-like B6.129S2-Apoe^tm1Unc/J mice and oxidized low-density lipoprotein (oxLDL) in tumor necrosis factor (TNF)-α-stimulated Hacat cells. In our study, we showed that a high-cholesterol diet aggravated psoriasis-like phenomena in IMQ-treated B6.129S2-Apoe^tm1Unc/J mice. In vitro analysis showed that oxLDL increased keratinocyte migration and lectin-type oxLDL receptor 1 (LOX-1) expression. Evidence suggested that interleukin (IL)-23 was a main cytokine in the pathogenesis of psoriasis. High-cholesterol diet aggravated IL-23 expression in IMQ-treated B6.129S2-Apoe^tm1Unc/J mice, and oxLDL induced IL-23 expression mediated by LOX-1 in TNF-α-stimulated Hacat cells. Therefore, it will be interesting to investigate the factors for the oxLDL induction of LOX-1 in psoriasis. LOX-1 receptor expression may be another novel treatment option for psoriasis and might represent the most promising strategy.

Molecular mechanisms of mechanotransduction in psoriasis

Psoriasis is an immune disease of the skin that frequently develops upon triggering events of mechanical nature and leads to increased proliferation and damaged differentiation of keratinocytes of the epidermis. Mechanical forces are mediated through mechanotransduction, which is the process that translates physical cues into biochemical signaling networks. Latest updates underline the role of mechanotransduction during the acquisition of aberrant properties by the keratinocytes of the skin, therefore implying a potential contribution that promotes psoriasis pathogenesis. The present review discusses the mechano-induced signaling pathways and individual molecules that become activated in psoriasis and in keratinocytes, along with mechano-based putative treatment strategies. We also suggest emerging mechanosensitive molecules for further investigation with potential diagnostic and therapeutic utility in psoriasis.

Mouse models of psoriasis and their relevance

Psoriasis is an inflammatory skin disorder that includes dynamic interactions between the immune system and skin and is clinically characterized by keratinocyte proliferation and distinct inflammatory cell infiltrates. Cross-talk between keratinocytes and immunocytes is essential for the development of psoriasis given that it mediates the production of cytokines, chemokines and growth factors. To resolve the pathogenesis of psoriasis, numerous experimental animal models have been generated. In this review, we discuss recent findings from mouse models, their relevancy to psoriasis and use, including the discovery of new therapies.

HLA-C*06:02 Does Not Predispose to Clinical Response Following Long-Term Adalimumab Treatment in Psoriatic Patients: A Retrospective Cohort Study

BACKGROUND

The genetic basis of predisposition to psoriasis is recognised; however, the response to psoriasis treatment in patients with different genetic predisposition is poorly understood.

OBJECTIVE

To analyse the presence of the HLA-C*06:02 polymorphism in psoriatic patients treated with adalimumab.

METHODS

Genomic DNA was extracted from whole blood of 122 patients with moderate-to-severe psoriasis treated with adalimumab for 3 years. Genotyping was performed using PCR. Disease severity was assessed by the Psoriasis Area and Severity Index (PASI) at day 0 and after 1, 3, 6, 12, 24 and 36 months. Logistic regression was used to evaluate the association between dependent variables (including HLA-C*06:02 status) and achievement of PASI 50, 75 and 90.

RESULTS

No difference was observed after adalimumab treatment between C*06:02 positive (HLA-C*06:02-POS) patients (n = 46) and C*06:02 negative (HLA-C*06:02-NEG) patients (n = 76) over the 3-year follow-up period in terms of PASI response or time-course when PASI response was achieved. However, a small, but non-statistically significant difference was noted between genotypes for PASI 50 at 1 month (HLA-C*06:02-NEG: 44.7% vs. HLA-C*06:02-POS: 56.5%) and at 3 months (HLA-C*06:02-NEG: 71.1% vs. HLA-C*06:02-POS: 80.4%). Simple logistic regression analysis did not reveal an association between independent variables (including C*06:02 status) and PASI response; however, multivariate regression revealed that gender (females better than males) was associated with achievement of PASI 50 at month 1 (OR 0.34, 95% CI 0.16-0.72, p = 0.005) and of PASI 75 at 3 months (OR 0.36, 95% CI 0.16-0.8, p = 0.012).

CONCLUSION

Adalimumab reduced long-term severity in patients with moderate-severe psoriasis, independent of their HLA-C*06:02 status.

HIV-Associated Psoriasis

Human immunodeficiency virus (HIV) prevalence is increasing worldwide as people on antiretroviral therapy are living longer. These patients are often susceptible to debilitating inflammatory disorders that are frequently refractory to standard treatment. Psoriasis is a systemic inflammatory disorder, associated with both physical and psychological burden, and can be the presenting feature of HIV infection. In this population, psoriasis tends to be more severe, to have atypical presentations and higher failure rates with the usual prescribed treatments. Management of moderate and severe HIV-associated psoriasis is challenging. Systemic conventional and biologic agents may be considered, but patients should be carefully followed up for potential adverse events, like opportunist infections, and regular monitoring of CD4 counts and HIV viral loads.

STAT2 is involved in the pathogenesis of psoriasis by promoting CXCL11 and CCL5 production by keratinocytes

The JAK/STAT signaling pathway is suggested to play an important role in the pathogenesis of psoriasis, and recently JAK/STAT inhibitors have shown promising results in psoriasis treatment. The present study aimed to characterize the role of STAT2 in psoriasis. We demonstrated an increased expression of STAT2 and an increased level of phosphorylated/activated STAT2 in lesional compared with nonlesional psoriatic skin. Gene silencing of STAT2 by siRNA in human keratinocytes revealed that upon IFNα stimulation CXCL11 and CCL5 were the only two cytokines, among 102 analyzed, found to be regulated through a STAT2-dependent mechanism. Moreover, the regulation of CXCL11 and CCL5 depended on IRF9, but not on STAT1 and STAT6. The CXCL11 and CCL5 expression was increased in lesional compared with nonlesional psoriatic skin, and analysis demonstrated positive correlation between the expression of CXCL11 and IFNγ and between the expression of CCL5 and IFNγ in lesional psoriatic skin. In contrast, no correlation between the expression of CXCL11 and IL-17A and the expression of CCL5 and IL-17A in lesional psoriatic skin was found. Our data suggest that STAT2 plays a role in the psoriasis pathogenesis by regulating the expression of CXCL11 and CCL5, and thereby attracting IFNγ-producing immune cells to the skin.

The phosphodiesterase 4 inhibitor apremilast inhibits Th1 but promotes Th17 responses induced by 6-sulfo LacNAc (slan) dendritic cells

BACKGROUND

The phosphodiesterase 4 (PDE4) inhibitor apremilast increases cellular cAMP levels and has proven effective in the treatment of psoriasis and psoriasis arthritis. We recently described 6-sulfo LacNAc dendritic cells (slanDCs) as immature DCs in blood and as a subset of inflammatory dermal DCs in psoriasis with a pronounced capacity to produce proinflammatory cytokines and to program Th17/Th1 T cell responses.

OBJECTIVE

The aim of this study was to investigate possible immune regulatory effects of the PDE4 inhibitor apremilast on slanDCs.

METHODS

In vitro studies were performed analyzing the effects of apremilast on the proinflammatory function of slanDCs and their capacity to induce Th1/Th17-biased T cell responses.

RESULTS

Increasing cAMP levels in slanDCs by PDE4 inhibition strongly reduced production of IL-12 and TNF-α. In line with these findings, co-culture experiments with apremilast-pulsed slanDCs and allogeneic T cells either from psoriasis patients or healthy controls, revealed a significant reduction of IFN-γ production and expression of the transcription factor T-bet. In parallel, production of IL-23 and IL-1ß by slanDCs was increased and co-cultured T cells revealed a largely augmented IL-17 production and an upregulated RORyt expression.

CONCLUSIONS

We here demonstrate anti-inflammatory as well as Th17-promoting effects of apremilast when studying blood precursors of human inflammatory dermal dendritic cells. In the concert of the broad anti-inflammatory effects of apremilast on keratinocytes, fibroblasts and endothelial cells, the dual effect on slan⁺ inflammatory dermal DCs should be taken into account and may constrain therapeutic responses.

Whole Exome Sequencing in Psoriasis Patients Contributes to Studies of Acitretin Treatment Difference

Psoriasis vulgaris is an immune-mediated inflammatory skin disease. Although acitretin is a widely used synthetic retinoid for moderate to severe psoriasis, little is known about patients’ genetics in response to this drug. In this study, 179 patients were enrolled in either the discovery set (13 patients) or replication set (166 patients). The discovery set was sequenced by whole exome sequencing and sequential validation was conducted in the replication set by MassArray assays. Four SNPs (single nucleotide polymorphisms) (rs1105223T>C in CRB2, rs11086065A>G in ANKLE1, rs3821414T>C in ARHGEF3, rs1802073 T>G in SFRP4) were found to be significantly associated with acitretin response in either co-dominant or dominant models via multivariable logistic regression analysis, while CRB2 rs1105223CC (OR = 4.10, 95% CI = 1.46–11.5, p = 0.007) and ANKLE1 rs11086065AG/GG (OR = 2.76, 95% CI = 1.42–5.37, p = 0.003) were associated with no response to acitretin after 8-week treatment. Meanwhile, ARHGEF3 rs3821414CT/CC (OR = 0.25, 95% CI = 0.10–0.68, p = 0.006) and SFRP4 rs1802073GG/GT (OR = 2.40, 95% CI, 1.23–4.70, p = 0.011) were associated with a higher response rate. Four new genetic variations with potential influences on the response to acitretin were found in this study which may serve as genetic markers for acitretin in psoriasis patients.