Immunopathogenesis and role of T cells in psoriasis

Reverse causation between multiple sclerosis and psoriasis: a genetic correlation and Mendelian randomization study

Observational studies have found a potential bidirectional positive association between multiple sclerosis and psoriasis, but these studies are susceptible to confounding factors. We examined the directionality of causation using Mendelian randomization and estimated the genetic correlation using the linkage disequilibrium score. We performed Mendelian randomization analysis using large-scale genome-wide association studies datasets from the International Multiple Sclerosis Genetics Consortium (IMSGC, 115,803 individuals of European ancestry) and FinnGen (252,323 individuals of European ancestry). We selected several Mendelian randomization methods including causal analysis using summary effect (CAUSE), inverse variance-weighted (IVW), and pleiotropy-robust methods. According to CAUSE and IVW the genetic liability to MS reduces the risk of psoriasis (CAUSE odds ratio [OR] 0.93, p = 0.045; IVW OR 0.93, p = 2.51 × 10-20), and vice versa (CAUSE OR 0.72, p = 0.001; IVW OR 0.71, p = 4.80 × 10-26). Pleiotropy-robust methods show the same results, with all p-values < 0.05. The linkage disequilibrium score showed no genetic correlation between psoriasis and MS (rg =  - 0.071, p = 0.2852). In summary, there is genetic evidence that MS reduces the risk of psoriasis, and vice versa.

Clinical pharmacokinetics and pharmacodynamics of oral systemic nonbiologic therapies for psoriasis patients

INTRODUCTION

Psoriasis is a chronic inflammatory immune condition. Treatments for psoriasis vary with disease severity, ranging from topicals to systemic biologic agents. The pharmacokinetic (PK) and pharmacodynamic (PD) properties of these therapies establish drug efficacy, toxicity, and optimal dosing to ensure therapeutic drug levels are sustained and adverse effects are minimized.

AREAS COVERED

A literature search was performed on PubMed, Google Scholar, and Ovid MEDLINE for PK and PD, efficacy, and safety data regarding oral systemic nonbiologic therapies utilized for moderate-to-severe plaque psoriasis. The findings were organized into sections for each drug: oral acitretin, methotrexate, cyclosporine, apremilast, tofacitinib, and deucravacitinib.

EXPERT OPINION

Some psoriasis patients may not respond to initial therapy. Ongoing research is evaluating genetic polymorphisms that may predict an improved response to specific medications. However, financial and insurance barriers, as well as limited genetic polymorphisms correlated with treatment response, may restrict the implementation of genetic testing necessary to personalize treatments. How well psoriasis patients adhere to treatment may contribute greatly to variation in response. Therapeutic drug monitoring may help patients adhere to treatment, improve clinical response, and sustain disease control.

Insights into Autophagic Machinery and Lysosomal Function in Cells Involved in the Psoriatic Immune-Mediated Inflammatory Cascade

Impaired autophagy, due to the dysfunction of lysosomal organelles, contributes to maladaptive responses by pathways central to the immune system. Deciphering the immune-inflammatory ecosystem is essential, but remains a major challenge in terms of understanding the mechanisms responsible for autoimmune diseases. Accumulating evidence implicates a role that is played by a dysfunctional autophagy-lysosomal pathway (ALP) and an immune niche in psoriasis (Ps), one of the most common chronic skin diseases, characterized by the co-existence of autoimmune and autoinflammatory responses. The dysregulated autophagy associated with the defective lysosomal system is only one aspect of Ps pathogenesis. It probably cannot fully explain the pathomechanism involved in Ps, but it is likely important and should be seriously considered in Ps research. This review provides a recent update on discoveries in the field. Also, it sheds light on how the dysregulation of intracellular pathways, coming from modulated autophagy and endolysosomal trafficking, characteristic of key players of the disease, i.e., skin-resident cells, as well as circulating immune cells, may be responsible for immune impairment and the development of Ps.

Assessment of cytochrome P450 1A1 gene polymorphism and vitamin A serum level in psoriasis vulgaris

Psoriasis is characterized by cutaneous hyperproliferation, secondary to immune system dysregulation. Vitamin A regulates the immune response and sustains epithelial tissue hemostasis. The CYP1A1 gene, has many biological actions, including vitamin A metabolism. To evaluate CYP1A1 gene polymorphism and serum vitamin A level in patients with psoriasis vulgaris, a case-control study involving two groups was conducted: group 1 (45 patients with psoriasis vulgaris) served as the cased group and group 2 (45 healthy participants who were sex and age matched) acted as the control group. CYP1A1 (rs1048943) gene polymorphism and vitamin A serum level were assessed by TaqMan allelic discrimination (PCR) and ELISA, respectively. AG genotype was present only in cases (22.2%), while AA genotype was present in all controls (P=.001). Vitamin A levels were lower in cases than in controls (32.0 ± 7.41 vs. 46.2 ± 15.7 μg/ml, respectively) (P<.001). AG genotype was associated with a lower vitamin A level (P=.001). The detected genotype difference between psoriasis patients and controls, which was associated with a lower serum vitamin A level and was also lower in more severe cases, suggests a role of the CYP1A1 gene and vitamin A in disease pathogenesis and prognosis.

Biologic insights from single-cell studies of psoriasis and psoriatic arthritis

INTRODUCTION

Psoriasis (PSO) and psoriatic arthritis (PSA) represent a large burden of global inflammatory disease, but sustained treatment response and early diagnosis remain challenging. Both conditions arise from complex immune cell dysregulation. Single-cell techniques, including single-cell RNA sequencing (scRNA-seq), have revolutionized our understanding of pathogenesis by illuminating heterogeneous cell populations and their interactions.

AREAS COVERED

We discuss the transcriptional profiles and cellular interactions unique to PSO/PSA affecting T cells, myeloid cells, keratinocytes, innate lymphoid cells, and stromal cells. We also review advances, limitations, and future challenges associated with single-cell studies.

EXPERT OPINION

Following analyses of 22 single-cell studies, several themes emerged. A small subpopulation of cells can have a large impact on disease pathogenesis. Multiple cell types identified via scRNA-seq play supporting roles in PSO pathogenesis, contrary to the traditional paradigm focusing on IL-23/IL-17 signaling among dendritic cells and T cells. Immune cell states are dynamic, with psoriatic subpopulations aberrantly re-activating and differentiating into inflammatory phenotypes depending on surrounding signaling cues. Comparison of circulating immune cells with resident skin/joint cells has uncovered specific T cell clonotypes associated with the disease. Finally, machine learning models demonstrate great promise in identifying biomarkers to diagnose clinically ambiguous rashes and PSA at earlier stages.

B7-H4 Polymorphism Influences the Prevalence of Diabetes Mellitus and Pro-Atherogenic Dyslipidemia in Patients with Psoriasis

Background: The co-inhibitory molecule B7-H4 is located in the genomic regions associated with type 1 diabetes (T1D) susceptibility. However, the correlation of B7-H4 with glycometabolism and dyslipidemia has never been studied. Objective: To explore the influence of B7-H4 polymorphism on the prevalence of diabetes mellitus (DM) and dyslipidemia in psoriasis. Methods: In this single-center cross-sectional study, we recruited 265 psoriatic patients receiving methotrexate (MTX) treatment. Thirteen single-nucleotide polymorphisms (SNPs) in B7-H4 were genotyped. Serum levels of total cholesterol (TC), triglycerides (TG), lipoprotein (a) (LP(a)), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB) were measured at baseline and week 12. Results: The GG genotype carriers of rs12025144 in B7-H4 had a higher prevalence of DM (57.14% vs. 17.71% vs. 18.67%, p = 0.0018), and had a poorer response to MTX in diabetic patients (p < 0.05), compared with AA or AG genotype carriers. The AG genotype of rs2066398 was associated with higher levels of pro-atherogenic lipids. MTX significantly downregulated the level of anti-atherogenic lipid ApoA1 in AA genotype carriers of rs2066398. Conclusions: The genotypes rs12025144 and rs2066398 in B7-H4 were correlated with a higher prevalence of DM and dyslipidemia in psoriasis, respectively.

Updated Perspectives on Keratinocytes and Psoriasis: Keratinocytes are More Than Innocent Bystanders

Psoriasis is a complex disease triggered by genetic, immunologic, and environmental stimuli. Many genes have been linked to psoriasis, like the psoriasis susceptibility genes, some of which are critical in keratinocyte biology and epidermal barrier function. Still, the exact pathogenesis of psoriasis is unknown. In the disease, the balance between the proliferative and differentiative processes of keratinocytes becomes altered. Multiple studies have highlighted the role of dysregulated immune cells in provoking the inflammatory responses seen in psoriasis. In addition to immune cells, accumulating evidence shows that keratinocytes are involved in psoriasis pathogenesis, as discussed in this review. Although certain immune cell-derived factors stimulate keratinocyte hyperproliferation, activated keratinocytes can also produce anti-microbial peptides, cytokines, and chemokines that can promote their proliferation, as well as recruit immune cells to help initiate and reinforce inflammatory feedback loops. Psoriatic keratinocytes also show intrinsic differences from normal keratinocytes even after removal from the in vivo inflammatory environment; thus, psoriatic keratinocytes have been found to exhibit abnormal calcium metabolism and possible epigenetic changes that contribute to psoriasis. The Koebner phenomenon, in which injury promotes the development of psoriatic lesions, also provides evidence for keratinocytes' contributions to disease pathogenesis. Furthermore, transgenic mouse studies have confirmed the importance of keratinocytes in the etiology of psoriasis. Finally, in addition to immune cells and keratinocytes, data in the literature support roles for other cell types, tissues, and systems in psoriasis development. These other contributors are all potential targets for therapies, suggesting the importance of a holistic approach when treating psoriasis.

Hydrogel-mediated topical delivery of steroids can effectively alleviate psoriasis via attenuating the autoimmune responses

Psoriasis is a systemic, relapsing, and chronic autoimmune inflammatory disease of the skin. Topical use of betamethasone, a glucocorticoid, in the form of creams is a common treatment for psoriasis. However, topical use of these creams is challenging due to the ineffective entrapment of steroids, burst release of the entrapped drugs, poor skin permeability, and high toxicity. Herein, we present the engineering of a betamethasone-loaded topical hydrogel (B-Gel) that can efficiently entrap steroids with high spreadability, and can also maintain the sustained release of drugs. We used an imiquimod (IMQ) induced ear psoriasis model, and demonstrated that topical application of B-Gel can mitigate the autoimmune inflammation reactions, and leads to a reduction in erythema, induration, scaling, and ear thickness. As interleukin 17 (IL-17) secreting T helper 17 (Th17) cells and γδ⁺ T cells are responsible for psoriasis, B-Gel treatment witnessed a reduction in the infiltration of leukocytes, CD4⁺ T cells, Th17 T cells, and dermal γδ⁺ T cells. We further demonstrated that B-Gel mediated reduction of IL-1β, IL-17, and K16 (marker for keratinocyte proliferation) is responsible for alleviation of psoriasis. Therefore, the non-greasy nature of the hydrogel with a cooling effect provides an alternative for topical application of steroids.

Papulosquamous Disorders and Pregnancy

Pregnancy can influence the course of a number of dermatologic disorders. Interestingly, these disorders can also influence pregnancy outcomes negatively, due to a variety of underlying pathogenic mechanisms. These outcomes may range from low fetal birth weight, preterm birth, and miscarriages to perineal lacerations complicating deliveries. Our review highlights the impact that papulosquamous disorders may have on pregnancy and their course throughout pregnancy. We chose papulosquamous disorders due to their relatively high prevalence worldwide compared to other dermatologic disorders. This review also sheds light on any gaps in the literature relevant to this topic that should be addressed. 

Curcumin alleviates imiquimod-induced psoriasis in progranulin-knockout mice

Recent advances have revealed that progranulin (PGRN) is related to the aetiology of psoriasis. Moreover, curcumin, a compound derived from turmeric, has been proposed as a potential therapeutic approach in psoriasis-like dermatitis, but it is still unclear whether curcumin affects the development of psoriasis-like skin lesions under PGRN-deficient conditions. Therefore, in this study, we developed a mouse model of psoriatic skin lesions using topical application of imiquimod (IMQ) in both wild type and PGRN-knockout mice to test this possibility. We observed that PGRN deficiency not only increased proinflammatory cytokine IL-17A levels and aggravated psoriasis-like damaged appearance and epidermal thickening but also directly mediated changes in keratinocyte proliferation (Krt 14, cyclinD1 and c-Myc) and differentiation (Krt 10 and Filaggrin) associated gene expression following IMQ challenge, compared to those in the control group. Furthermore, curcumin treatment (50 mg/kg and 200 mg/kg, intragastrically) for 21 consecutive days suppressed the IMQ exposure-induced increase in PGRN expression. Importantly, curcumin treatment significantly alleviated the PGRN deficiency-induced exacerbation of psoriatic appearance, histological features and keratinocyte proliferation after IMQ exposure. In summary, these results demonstrate the direct regulation of PGRN in keratinocyte proliferation and differentiation in psoriatic lesions and demonstrate the protective effect of curcumin on PGRN deficiency-induced psoriatic skin lesion exacerbation.

Cudraxanthone D Ameliorates Psoriasis-like Skin Inflammation in an Imiquimod-Induced Mouse Model via Inhibiting the Inflammatory Signaling Pathways

Psoriasis is a chronic inflammatory skin disease accompanied by excessive keratinocyte proliferation. Corticosteroids, vitamin D3 analogs, and calcineurin inhibitors, which are used to treat psoriasis, have diverse adverse effects, whereas natural products are popular due to their high efficiency and relatively low toxicity. The roots of the Cudrania tricuspidata (C. tricuspidata) are known to have diverse pharmacological effects, among which the anti-inflammatory effect is reported as a potential therapeutic agent in skin cells. Nevertheless, its effectiveness against skin diseases, especially psoriasis, is not fully elucidated. Here, we investigated the effect of cudraxanthone D (CD), extracted from the roots the C. tricuspidata Bureau, on psoriasis using an imiquimod (IMQ)-induced mouse model and the tumor necrosis factor (TNF)-α/interferon (IFN)-γ-activated keratinocytes. IMQ was topically applied to the back skin of C57BL/6 mice for seven consecutive days, and the mice were orally administered with CD. This resulted in reduced psoriatic characteristics, such as the skin thickness and Psoriasis Area Severity Index score, and the infiltration of neutrophils in IMQ-induced skin. CD inhibited the serum levels of TNF-α, immunoglobulin G2a, and myeloperoxidase, and the expression of Th1/Th17 cells in splenocytes. In TNF-α/IFN-γ-activated keratinocytes, CD reduced the expressions of CCL17, IL-1β, IL-6, and IL-8 by inhibiting the phosphorylation of STAT1 and the nuclear translocation of NF-kB. Taken together, these results suggest that CD could be a potential drug candidate for the treatment of psoriasis.

Valosin-containing Protein in Psoriasis: A Clinical and Immunohistochemical Study

Psoriasis is a chronic immune-mediated inflammatory skin disease, affects about 2% to 3% of the world population. Valosin-containing protein (VCP) is one of the newly discovered markers that is highly expressed in neoplasms and hyperproliferative lesions. This work aimed to study the role of VCP in psoriasis vulgaris by immunohistochemical study and correlate its expression with the available clinicopathologic data. This prospective case-control study was conducted on 25 patients with psoriasis vulgaris and 25 age-matched and sex-matched healthy individuals as a control group. Skin biopsies were taken under local anesthesia from cases and controls. VCP immunoreactivity showed that epidermal VCP expression had a significant stepwise increase (P=0.002) from control to lesional psoriatic sections. Epidermal VCP H-score was significantly associated with the progressive course (P=0.037). Similarly, VCP in the dermis showed a significant expression in lesional psoriatic skin (P≤0.001). Higher VCP in the dermis in cases with a history of joint affection (P<0.05) was detected. We concluded that VCP is a promising marker for follow-up and monitoring of psoriatic patients and may play a role as a therapeutic target.

Hispidulin alleviates imiquimod-induced psoriasis-like skin inflammation by inhibiting splenic Th1/Th17 cell population and keratinocyte activation

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and abnormal differentiation of epidermal keratinocytes accompanied by increased infiltration of immune cells. Previous studies have demonstrated that hispidulin (4',5,7-trihydroxy-6-methoxyflavone, HPD) has various pharmacological benefits such as anti-fungal, anti-inflammation, and anti-allergic effects. This study investigated the effectiveness of HPD to treat psoriasis using an imiquimod (IMQ)-induced mouse model and activated keratinocytes. IMQ was topically applied to the back skin of mice for six consecutive days, and the mice were orally administered HPD. Based on the histological observation and immunological analysis, oral administration of HPD suppressed psoriatic characteristics including skin thickness, psoriasis area severity index, transepidermal water loss, and neutrophil infiltration. HPD alleviated pathologically increased levels of immunoglobulin G2a, myeloperoxidase, and tumor necrosis factor-α. Splenic Th1 and Th17 cell populations were also reduced by HPD in the murine model. In addition, in activated keratinocytes, HPD inhibited gene expression of Th1- and Th17-associated cytokines and chemokines, and phosphorylation of mitogen-activated protein kinases and nuclear factor-κB. In summary, HPD alleviates psoriasis skin inflammation in vivo and in vitro. Therefore, we suggest that HPD would be a potent therapeutic candidate for the treatment of psoriasis.

Piperlongumine regulates epigenetic modulation and alleviates psoriasis-like skin inflammation via inhibition of hyperproliferation and inflammation

Psoriasis is an autoimmune skin disease, where chronic immune responses due to exaggerated cytokine signaling, abnormal differentiation, and evasion of keratinocytes apoptosis plays a crucial role in mediating abnormal keratinocytes hyperproliferation. From the therapeutic perspective, the molecules with strong anti-proliferative and anti-inflammatory properties could have tremendous relevance. In this study, we demonstrated that piperlongumine (PPL) treatment effectively abrogated the hyperproliferation and differentiation of keratinocytes by inducing ROS-mediated late apoptosis with loss of mitochondrial membrane potential. Besides, the arrest of cell cycle was found at Sub-G1 phase as a result of DNA fragmentation. Molecularly, inhibition of STAT3 and Akt signaling was observed with a decrease in proliferative markers such as PCNA, ki67, and Cyclin D1 along with anti-apoptotic Bcl-2 protein expression. Keratin 17 is a critical regulator of keratinocyte differentiation, and it was found to be downregulated with PPL significantly. Furthermore, prominent anti-inflammatory effects were observed by inhibition of lipopolysaccharide (LPS)/Imiquimod (IMQ)-induced p65 NF-κB signaling cascade and strongly inhibited the production of cytokine storm involved in psoriasis-like skin inflammation, thus led to the restoration of normal epidermal architecture with reduction of epidermal hyperplasia and splenomegaly. In addition, PPL epigenetically inhibited histone-modifying enzymes, which include histone deacetylases (HDACs) of class I (HDAC1-4) and class II (HDAC6) evaluated by immunoblotting and HDAC enzyme assay kit. In addition, our results show that PPL effectively inhibits the nuclear translocation of p65 and a histone modulator HDAC3, thus sequestered in the cytoplasm of macrophages. Furthermore, PPL effectively enhanced the protein-protein interactions of HDAC3 and p65 with IκBα, which was disrupted by LPS stimulation and were evaluated by Co-IP and molecular modeling. Collectively, our findings indicate that piperlongumine may serve as an anti-proliferative and anti-inflammatory agent and could serve as a potential therapeutic option in treating psoriasis.

Neutrophil extracellular trap-associated RNA and LL37 enable self-amplifying inflammation in psoriasis

Psoriasis is an inflammatory skin disease with strong neutrophil (PMN) infiltration and high levels of the antimicrobial peptide, LL37. LL37 in complex with DNA and RNA is thought to initiate disease exacerbation via plasmacytoid dendritic cells. However, the source of nucleic acids supposed to start this initial inflammatory event remains unknown. We show here that primary murine and human PMNs mount a fulminant and self-propagating neutrophil extracellular trap (NET) and cytokine response, but independently of the canonical NET component, DNA. Unexpectedly, RNA, which is abundant in NETs and psoriatic but not healthy skin, in complex with LL37 triggered TLR8/TLR13-mediated cytokine and NET release by PMNs in vitro and in vivo. Transfer of NETs to naive human PMNs prompts additional NET release, promoting further inflammation. Our study thus uncovers a self-propagating vicious cycle contributing to chronic inflammation in psoriasis, and NET-associated RNA (naRNA) as a physiologically relevant NET component.

Altered expression of regulatory molecules in the skin of psoriasis

The presence of T regulatory cells (Tregs) is highly required in normal skin in order to maintain immune tolerance to commensal microbes and to prevent the development of immune-mediated inflammation. Psoriasis is a chronic inflammatory skin disease in which effector T cells, namely, Th17 and their relevant pro-inflammatory cytokines are increased in peripheral blood as well as in the inflamed skin. The status of Tregs in psoriatic skin is continuously studied. In this case, CD4 + CD25high T cells and other regulatory cytokines such as IL-35 are demonstrated to be significantly decreased. Aiming to better characterize Tregs in psoriatic skin and to establish the finding of their abnormal balance, we assessed the expression of semaphorin3A and neuropilin-1 (both reported as biomarkers of Tregs). Semaphorin3A and neuropilin-1 expressing Tregs were found to be significantly decreased in psoriatic skin when compared to normal skin. These findings were supported by demonstrating the downregulation of IL-10 expression in psoriatic skin. Our findings suggest that semaphoring3A may turn to be a new promising therapeutic approach in the process of improving Treg function in psoriasis.

Serum Concentrations of Interferon Gamma (IFN-γ) in Patients with Psoriasis: Correlation with Clinical Type and Severity of the Disease

Introduction:

The etiopathogenesis of psoriasis is still unclear but there is evidence that many of cytokines released by keratinocytes and inflammatory leukocytes may contribute to the induction or persistence of the inflammatory process in psoriasis.

Aim:

The aim of the study was to evaluate serum concentrations of Interferon gamma (IFN-γ) in patients with psoriasis and the healthy subjects and also to assess a possible association between IFN-γ, clinical type and severity of disease.

Material and Methods:

The study included a total of 60 patients with psoriasis and 20 healthy subjects in the control group. According to the clinical type of disease, patients with psoriasis were divided into four groups: psoriasis vulgaris (PV), psoriasis erythrodermica (PE), psoriasis pustulosa (PP) and psoriasis arthropatica (PA). Blood samples were collected from all psoriasis patients and from healthy control subjects. Serum IFN-γ levels were measured by an enzyme-linked immunosorbent assay (ELISA) technique. The severity of PV was assessed by Psoriasis Area and Severity Index (PASI) score.

Results:

The serum concentration of IFN-γ in patients with psoriasis was significantly higher than that in the control group (1.91±1.79 pg/mL vs 0.91±0.38 pg/mL, respectively). Significantly elevated serum IFN-γ concentrations were noticed in patients with PV (2.15±0.30 pg/mL). There was no statistically significant difference between the mean values of IFN- γ compared to the clinical type of psoriasis (p>0.05). In the group of patients with PV 36 (85.71%) patients had mild form of disease with PASI <50, and 6 (14.29%) patients had severe disease with PASI >50. It was not found statistically significant correlation between serum IFN-γ level and PASI score in the group of PV.

Conclusions:

The results of our study indicate that psoriasis is associated with significant changes in the serum concentration of IFN-γ. There was no significant correlation between serum IFN-γ concentrations, clinical type of psoriasis and severity of PV evaluated with the use of PASI score.

Adaptive and Innate Immunity in Psoriasis and Other Inflammatory Disorders

Over the past three decades, a considerable body of evidence has highlighted T cells as pivotal culprits in the pathogenesis of psoriasis. This includes the association of psoriasis with certain MHC (HLA) alleles, oligoclonal expansion of T cells in some cases, therapeutic response to T cell-directed immunomodulation, the onset of psoriasis following bone marrow transplantation, or induction of psoriasis-like inflammation by T cells in experimental animals. There is accumulating clinical and experimental evidence suggesting that both autoimmune and autoinflammatory mechanisms lie at the core of the disease. Indeed, some studies suggested antigenic functions of structural proteins, and complexes of self-DNA with cathelicidin (LL37) or melanocytic ADAMTSL5 have been proposed more recently as actual auto-antigens in some cases of psoriasis. These findings are accompanied by various immunoregulatory mechanisms, which we increasingly understand and which connect innate and adaptive immunity. Specific adaptive autoimmune responses, together with our current view of psoriasis as a systemic inflammatory disorder, raise the question of whether psoriasis may have connections to autoimmune or autoinflammatory disorders elsewhere in the body. While such associations have been suspected for many years, compelling mechanistic evidence in support of this notion is still scant. This review sets into context the current knowledge about innate and adaptive immunological processes in psoriasis and other autoimmune or autoinflammatory diseases.

Immunohistochemical study of janus kinase 1/signal transducer and activator of transcription 3 in psoriasis vulgaris

Background: Human JAKs are responsible for generating docking sites for human SSTAT phosphorylation. The role of JAKs in psoriasis pathogenesis has not been clearly explained. Aim: To investigate the role of JAK1 in psoriasis pathogenesis and to assess if this role is mediated through STAT3 or not, through evaluation of their immunohistochemical expression in the skin of psoriatic patients. Methods: This case-control study was carried out on 26 patients presenting with psoriasis vulgaris versus 26 age- and sex-matched apparently healthy volunteers. Psoriasis Area and Severity Index (PASI) scores were used to evaluate psoriasis severity. From all controls and cases (lesional and perilesional), skin biopsies were taken for histopathological and immunohistochemical JAK1 and STAT3 evaluation. Results: There was significant stepwise upregulation of JAK1 from controls to perilesional to lesional psoriatic skin of the patient group in both epidermis and dermis (P≤0.001 for both). Dermal JAK1 H-score was significantly associated with psoriasis severity (P=0.01). STAT3 was significantly overexpressed in lesional psoriatic skin over nonlesional skin (P<0.001). There were significant positive correlations between lesional H-scores for STAT3 and Psoriasis Area and Severity Index scores in epidermis (r=0.63, P<0.001), and in dermis (r=0.47, P=0.04). There was a significant positive correlation between JAK1 and STAT3 expression in epidermal lesional psoriatic skin (r=0.44, P=0.03). Conclusion: JAK1 has a proinflammatory effect in psoriasis pathogenesis, which could be mediated through increasing STAT3 expression in psoriasis. JAK1 and STAT3 tissue expression could be markers of psoriasis severity. JAK1 may be used as a target for immunotherapy in psoriasis-management programs.

Therapeutic Effects of Synthetic Antimicrobial Peptides, TRAIL and NRP1 Blocking Peptides in Psoriatic Keratinocytes

Psoriasis is a chronic, recurrent, heterogeneous, cutaneous inflammatory skin disease for which there is no cure. It affects approximately 7.5 million people in the United States. Currently, several biologic agents that target different molecules implicated in the pathogenic processes of psoriasis are being assessed in diverse clinical studies. However, relapse usually occurs within weeks or months, meaning there is currently no cure for psoriasis. Therefore, recent studies have discovered diverse new potential treatments for psoriasis: inhibitors of bacteria such as Staphylococcus aureus, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and neuropilin 1 (NRP1). A promising approach that has recently been described involves modifying antimicrobial peptides to develop new cutaneous anti-bacterial agents that target inflammatory skin disease induced by Staphylococcus. Increased expression of TRAIL and its death receptors DR4 and DR5 has been implicated in the pathogenesis of plaque psoriasis. In addition, TRAIL has the ability to inhibit angiogenesis by inducing endothelial cell death and by negative regulation of VEGF-induced angiogenesis via caspase-8-mediated enzymatic and non-enzymatic functions. Since NRP1 regulates angiogenesis induced by multiple signals, including VEGF, ECM and semaphorins, and also initiates proliferation of keratinocytes through NF-κB signaling pathway in involved psoriatic skin, targeting NRP1 pathways may offer numerous windows for intervention in psoriasis. In this review, we will focus on the current knowledge about the emerging role of synthetic antimicrobial peptides, TRAIL and NRP1 blocking peptides in the pathogenesis and treatment of psoriasis.

Progranulin and beta-catenin in psoriasis: An immunohistochemical study

BACKGROUND/OBJECTIVES

Progranulin (PGRN) is a secreted glycoprotein that was investigated in many skin diseases. It plays an important role in inflammatory response and autophagy which could be mediated through Wnt/β-catenin pathway. However, the role of PGRN in pathogenesis of psoriasis has not been clearly well-known. Therefore, we aimed by this study to investigate the possible role of progranulin in psoriasis pathogenesis through evaluation of its immunohistochemical expression in lesional and perilesional skin of psoriasis patients and to investigate if its hypothesized role is mediated through β-catenin or not.

METHODS

This case-control study was carried out on 37 patients presented with variable degrees of psoriasis vulgaris severity vs 37 age and sex-matched apparently healthy volunteers. Psoriasis area and severity index (PASI) score was used to evaluate the severity of psoriasis. From all cases (lesional and perilesional) and controls, skin biopsies were taken for histopathological and immunohistochemical evaluation of PGRN and β-catenin.

RESULTS

There was a significant stepwise upregulation of PGRN from controls (76.2 ± 11.9) to perilesional (178.7 ± 11.8) and lesional (242.7 ± 12.7) psoriatic skin (P < 0.001). PGRN expression was significantly correlated with psoriasis severity (r = 0.61; P < 0.001). β-catenin showed a significant stepwise downregulation from control (210.0 ± 19.3) to perilesional (131.4 ± 9.2) and lesional (97.3 ± 11.5) psoriatic skin(P < 0.001). There was a significant negative correlation between PGRN and β-catenin expression in psoriatic skin (P < 0.001).

CONCLUSIONS

Progranulin has a pro-inflammatory effect in the psoriasis pathogenesis, which could be mediated through a decreasing β-catenin expression in psoriasis. PGRN may be used as a target for immunotherapy in psoriasis management program.

Case of coincident severe acne and psoriasis in AIDS patient successfully treated with antiretroviral therapy

Cutaneous disorders remain a major problem in HIV-infected patients, even under antiretroviral therapy (ART). Patients at any stage of HIV/AIDS may suffer from skin lesions. Acnes and psoriasis are both common chronic and inflammatory skin diseases, and the treatment becomes more challenging and complex when combined with HIV infection. Whether the incidence and severity of acne and psoriasis are related to HIV infection is still controversial. Here, we report a rare case of an AIDS patient who developed severe acne along with psoriasis. The patient had initially received multiple systemic and topical antipsoriatic and anti-acne treatments which failed. Ultimately, he achieved dramatic clinical improvement after initiation of ART for main treatment. An 8-year follow up demonstrated that the patient has been free of symptoms of both psoriasis and acne till now.

A Preliminary Study of the Effect of Semaphorin 3A and Acitretin on the Proliferation, Migration, and Apoptosis of HaCaT Cells

Background:

Vascular endothelial growth factor (VEGF) is significantly elevated in psoriatic patients and is associated with the severity of the psoriasis. Due to the effect of inhibiting production of VEGF, acitretin can effectively treat psoriasis. Semaphorin 3A (Sema3A) restrain tumor growth and angiogenesis by partially reversing VEGF effects on tumor. However, the role of Sema3A in the pathogenesis of psoriasis is unclear.

Aims and Objectives:

This study aimed to investigate the effect of VEGF, Sema3A, and acitretin on HaCaT cells, to see whether Sema3A could be a beneficial factor in psoriasis, as well as acitretin.

Materials and Methods:

Functional analysis of VEGF, Sema3A, and acitretin was carried out using HaCaT cells cultured under different treatments. Cell counting kit-8 method, colony formation assay, flow cytometry, transwell migration, reverse transcription-polymerase chain reaction, and Western blot test were performed to measure proliferation, colony formation, migration, apoptosis, and the expression of Bcl2, Bax, Caspase 3, and Caspase 9 of HaCaT cells.

Results:

Sema3A and acitretin inhibited the proliferation, colony formation, and migration of HaCaT cells, while induced the apoptosis of HaCaT cells by inhibiting the expression of Bcl2, and promoting the expression of Bax, Caspase 3, and Caspase 9, which were opposite to VEGF. Sema3A and acitretin partially reversed the function of VEGF.

Conclusions:

Like acitretin, exogenous supplement of Sema3A may correct the abnormal proliferation and apoptosis procedure of HaCaT cells, and partially reverse the function of VEGF.

Type 2 Diabetes: How Much of an Autoimmune Disease?

Type 2 diabetes (T2D) is characterized by a progressive status of chronic, low-grade inflammation (LGI) that accompanies the whole trajectory of the disease, from its inception to complication development. Accumulating evidence is disclosing a long list of possible "triggers" of inflammatory responses, many of which are promoted by unhealthy lifestyle choices and advanced age. Diabetic patients show an altered number and function of immune cells, of both innate and acquired immunity. Reactive autoantibodies against islet antigens can be detected in a subpopulation of patients, while emerging data are also suggesting an altered function of specific T lymphocyte populations, including T regulatory (Treg) cells. These observations led to the hypothesis that part of the inflammatory response mounting in T2D is attributable to an autoimmune phenomenon. Here, we review recent data supporting this framework, with a specific focus on both tissue resident and circulating Treg populations. We also propose that selective interception (or expansion) of T cell subsets could be an alternative avenue to dampen inappropriate inflammatory responses without compromising immune responses.

Proanthocyanidins: novel treatment for psoriasis that reduces oxidative stress and modulates Th17 and Treg cells

Psoriasis is a common, chronic, inflammatory skin disease that affects 2%-4% of the global population. Recent studies have shown that increased oxidative stress (OS) and T-cell abnormalities are central to the pathogenesis of this disease. The resulting reactive oxygen species (ROS) induces proliferation and differentiation of Th17/Th1/Th22 cells and inhibits the anti-inflammatory activities of regulatory T lymphocytes (Treg). Subsequent secretions of inflammatory cytokines, such as interleukin (IL)-17, IL-22, tumor necrosis factor alpha (TNF-α), and interferon-gamma (IFN-γ), and vascular endothelial growth factor (VEGF), stimulate keratinocyte proliferation and angiogenesis. Proanthocyanidins are a class of flavonoids from plants and fruits, and have various antioxidant, anti-inflammatory, and anti-angiogenic properties. Numerous reports have demonstrated therapeutic effects of proanthocyanidins for various diseases. Among clinical activities, proanthocyanidins suppress cell proliferation, prevent OS, and regulate Th17/Treg cells. Because the pathogenesis of psoriasis involves OS and T cells dysregulation, we reviewed the effects of proanthocyanidins on OS, Th17 and Treg cell activities, and keratinocyte proliferation and angiogenesis. Data from multiple previous studies warrant consideration of proanthocyanidins as a promising strategy for the treatment of psoriasis.

The Interleukin-23/Interleukin-17 Axis Links Adaptive and Innate Immunity in Psoriasis

Research into the pathophysiology of psoriasis has shed light onto many fascinating immunological interactions and underlying genetic constellations. Most prominent among these is the crosstalk between components of the innate and the adaptive immune system and the crucial role of interleukins (IL)-23 and -17 within this network. While it is clear that IL-23 drives and maintains the differentiation of Th17 lymphocytes, many aspects of the regulation of IL-23 and IL-17 are not quite as straightforward and have been unraveled only recently. For example, we know now that Th17 cells are not the only source of IL-17 but that cells of the innate immune system also produce considerable amounts of this central effector cytokine. In addition, there is IL-23-independent production of IL-17. Besides other innate immune cells, neutrophilic granulocytes prominently contribute to IL-17-related immune regulations in psoriasis, and it appears that they employ several mechanisms including the formation of neutrophil extracellular traps. Here, we strive to put the central role of the IL-23/IL-17 axis into perspective within the crosstalk between components of the innate and the adaptive immune system. Our aim is to better understand the complex immune regulation in psoriasis, a disorder that has become a model disease for chronic inflammation.

Pathophysiological basis of systemic treatments in psoriasis

Over the past 15 years, the spectrum of systemic antipsoriatic treatments has dramatically expanded. Until the end of the last millennium, systemic therapy had been restricted to four oral agents: methotrexate, cyclosporine, acitretin, and fumaric acid esters. Today, there are additionally seven biologics and one new oral antipsoriatic drug, as well as the first available biosimilars. Six more biologics with novel target structures and at least four biosimilars are currently being developed (phase III). This progress has been based on new insights into the pathogenesis of psoriasis, in which tumor necrosis factor and especially Th17 immune responses with their associated cytokines interleukin 23 and 17 play a key role. The development of new-generation biologics as well as immunomodulatory small molecules can be attributed to these pathophysiological findings. Phosphodiesterase 4 inhibitors, dimethyl fumarate, and Janus kinase inhibitors all interact with Th17 immune responses. Some of these drugs are in advanced clinical development and are also beneficial in psoriatic arthritis. Today, psoriasis and psoriatic arthritis therefore rank among the most readily treatable inflammatory autoimmune disorders. Dermatology is increasingly becoming a specialty of modern targeted immunotherapies.

Ixekizumab treatment shows a neutral impact on cardiovascular parameters in patients with moderate-to-severe plaque psoriasis: Results from UNCOVER-1, UNCOVER-2, and UNCOVER-3

BACKGROUND

The impact of ixekizumab treatment for psoriasis on cardiovascular-related parameters in patients is unknown.

OBJECTIVE

To investigate cardiovascular-related parameters in patients with psoriasis treated with ixekizumab.

METHODS

In phase 3 trials, patients with moderate-to-severe psoriasis were randomized and treated with placebo, ixekizumab, or etanercept during the induction period (weeks 0-12; UNCOVER-1, UNCOVER-2, and UNCOVER-3). At week 12, responders were rerandomized to receive placebo or ixekizumab through the maintenance period (weeks 12-60; UNCOVER-1 and UNCOVER-2). Laboratory measures (fasting lipid profiles, glucose level, or high-sensitivity C-reactive protein [hsCRP] level), weight, blood pressure, and electrocardiograms were obtained through 60 weeks.

RESULTS

Baseline parameters were within normal ranges with the exception of elevated triglyceride and hsCRP levels. After maintenance dosing, no significant changes were observed versus placebo for total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol, triglyceride, apolipoprotein A1, apolipoprotein B, or fasting glucose levels or for systolic/diastolic blood pressure at 60 weeks. Importantly, low-density lipoprotein-to-high-density lipoprotein ratios remained stable during the induction and maintenance periods. HsCRP concentrations were significantly reduced versus placebo at 12 weeks and remained reduced at 60 weeks, although not significantly. Although transient changes were observed for some parameters during the induction period, these changes did not persist into the maintenance period.

LIMITATIONS

A lack of echocardiogram evaluations.

CONCLUSIONS

Ixekizumab had a neutral impact on cardiovascular-related parameters in patients with psoriasis.

Study of serum levels and skin expression of S100B protein in psoriasis

Background

S100B protein was reported to be elevated in psoriatic patients' serum, with no previous evaluation of its skin expression, in contrast to the extensively studied S100 protein.

Objective

To evaluate the serum level and skin expression of S100B in psoriasis to assess its possible involvement in its pathogenesis.

Methods

Serum level of S100B protein was estimated in 40 psoriatic patients of different clinical varieties and 10 healthy controls. S100B protein expression was assessed immunohistochemically in lesional and non-lesional skin of patients and in normal skin of controls. Relation to disease severity was also evaluated.

Results

Serum level of S100B protein was significantly higher in psoriatic patients (0.15±0.03 µg/l) than in controls (0.03±0.007 µg/l) (P-value <0.001) with no significant correlation with PASI score. On comparing grades of S100B protein skin expression in lesional and non-lesional skin biopsies, a statistically significant difference was found (P=0.046) with higher percentage of strong S100B skin expression (60%) in non-lesional than in lesional (42%) skin. All the control biopsies showed negative expression.

Study limitations

Relatively small sample size with a limited range of low PASI scores.

Conclusion

This study points to a potential link between psoriasis and S100B protein with higher serum and skin expression in patients than in controls.

Safety and efficacy of etanercept monotherapy for moderate-to-severe plaque psoriasis: A prospective 12-week follow-up study

Etanercept has been shown to be effective for the treatment of moderate-to-severe plaque psoriasis. Since most clinical trials examined etanercept in combination with other drugs, the efficacy and safety of etanercept monotherapy for moderate-to-severe plaque psoriasis have not been well established. This prospective study enrolled 61 Chinese patients with moderate-to-severe plaque psoriasis to explore the efficacy and safety of etanercept monotherapy. These patients were treated with etanercept at a subcutaneous dose of 25 mg, twice a week, for 12 weeks. All the 61 patients completed the treatment and showed significant improvement in psoriasis area and severity index (PASI) scores. At 4, 8, and 12 weeks after treatment, the response rates (PASI75) were 0%, 21.31%, and 40.98%, respectively. It was concluded that etanercept monotherapy is efficacious and safe for patients with moderate- to-severe plaque psoriasis.

Interferon-Gamma DNA Methylation Is Affected by Mycophenolic Acid but Not by Tacrolimus after T-Cell Activation

Immunosuppressive drug therapy is required to treat patients with autoimmune disease and patients who have undergone organ transplantation. The main targets of the immunosuppressive drugs tacrolimus and mycophenolic acid (MPA; the active metabolite of mycophenolate mofetil) are T cells. It is currently unknown whether these immunosuppressive drugs have an effect on DNA methylation—an epigenetic regulator of cellular function. Here, we determined the effect of tacrolimus and MPA on DNA methylation of the gene promoter region of interferon gamma (IFNγ), a pro-inflammatory cytokine. Total T cells, naive T cells (CCR7⁺CD45RO⁻), and memory T cells (CD45RO⁺ and CCR7⁻CD45RO⁻) were isolated from CMV seropositive healthy controls and stimulated with α-CD3/CD28 in the presence or absence of tacrolimus or MPA. DNA methylation of the IFNγ promoter region was quantified by pyrosequencing at 4 h, days 1, 3, and 4 after stimulation. In parallel, T-cell differentiation, and IFNγ protein production were analyzed by flow cytometry at days 1 and 3 after stimulation. Our results show that MPA induced changes in IFNγ DNA methylation of naive T cells; MPA counteracted the decrease in methylation after stimulation. Tacrolimus did not affect IFNγ DNA methylation of naive T cells. In the memory T cells, both immunosuppressive drugs did not affect IFNγ DNA methylation. Differentiation of naive T cells into a central-memory-like phenotype (CD45RO⁺) was inhibited by both immunosuppressive drugs, while differentiation of memory T cells remained unaffected by both MPA and tacrolimus. IFNγ protein production was suppressed by tacrolimus. Our results demonstrate that MPA influenced IFNγ DNA methylation of naive T cells after stimulation of T cells, while tacrolimus had no effect. Both tacrolimus and MPA did not affect IFNγ DNA methylation of memory T cells.

Immunometabolism of human autoimmune diseases: from metabolites to extracellular vesicles

Immunometabolism focuses on the mechanisms regulating the impact of metabolism on lymphocyte activity and autoimmunity outbreak. The adipose tissue is long known to release adipokines, either pro- or anti-inflammatory factors bridging nutrition and immune function. More recently, adipocytes were discovered to also release extracellular vesicles (EVs) containing a plethora of biological molecules, including metabolites and microRNAs, which can regulate cell function/metabolism in distant tissues, suggesting that immune regulatory function by the adipose tissue may be far more complex than originally thought. Moreover, EVs were also identified as important mediators of immune cell-to-cell communication, adding a further microenvironmental mechanism of plasticity to fine-tune specific lymphocyte responses. This Review will first focus on the known mechanisms by which metabolism impacts immune function, presenting a systemic (nutrition and long-ranged adipokines) and a cellular point of view (metabolic pathway derangement in autoimmunity). It will then discuss the new discoveries concerning how EVs may act as nanometric vehicles integrating immune/metabolic responses at the level of the extracellular environment and affecting pathological processes.

Immunohistochemical Expression of Caspase-3 in Psoriasis

INTRODUCTION

Psoriasis is a persistent chronic immune-mediated, relapsing, inflammatory and hyper proliferative skin disorder with genetic predisposition. Psoriasis can be considered as a T-cell mediated disease, with a complex role for a variety of cytokine interaction between keratinocytes and T-lymphocytes. Caspase-3 is an enzyme that plays a key role in apoptosis; it is a member of the family of cysteinyle aspartate specific proteases.

AIM

To evaluate the expression of caspase-3 in Egyptian psoriasis patients and its role in apoptosis of keratinocytes. Also, to correlate this expression with the clinicopathological parameters in order to identify the possible hypothesized role of caspase-3 in the pathogenesis of psoriasis.

MATERIALS AND METHODS

This was a case-control study conducted on patients suffering from chronic plaque psoriasis. A total of 20 psoriasis patients and 10 controls were selected from outpatient clinic of Dermatology, Menoufia University Hospital, between the period of October 2014 and January 2016. From each patient and control, a punch biopsy was taken. Evaluation of H&E stained sections and caspase-3 expression was done using standard immunohi-stochemical techniques. Non-parametric chi-square test, Mann-Whitney U test, Kruskal Wallis test and Spearman's coefficient test were the statistical tests used.

RESULTS

High caspase-3 H score was significantly in favour of psoriatic group in comparison with the control group. On the contrary, in the dermis, caspase-3 was significantly higher in skin adnexa while completely absent in the psoriatic group. Strong caspase-3 expression was significantly in favour of high PASI score, early onset lesions and lesions in the extremities. Significant positive correlation was found between caspase-3 percent and PASI score (r= +0.53, p-value=0.03).

CONCLUSION

Caspase-3 over expression in the psoriatic lesion proposes a potential role in the pathogenesis of psoriasis. Positive correlation between the caspase-3 expression and the early onset psoriatic lesion located in the extremities implies a possible poor prognostic impact of caspase-3 over expression.

MiR-155 promotes cell proliferation and inhibits apoptosis by PTEN signaling pathway in the psoriasis

MicroRNAs (miRNAs) have been demonstrated to contribute to malignant progression in psoriasis development. The purposes of the study was to evaluated the effects of miRNA-155 on cell proliferation, migration and apoptosis in psoriasis development via PTEN singaling pathway and identify its direct target protein. Quantitative real-time RT-PCR (qRT-PCR) was performed to examine the level of miR-155 in psoriasis cells, miR-155 was downregulated in a psoriasis cell line Hacat by transfected with small interfering RNA (siRNA), respectively. Cell survival was detected by the MTT assay and colony formation assay. Cell migration and invasion were measured via wound-healing assayand transwell assay. In addition, cell cycle and apoptosis about psoriasis cells was measured by flow cytometry. In this study, qRT-PCR assay showed that the expressions of miR-155 mRNA in psoriasis tissues were significantly higher than that in normal tissues. The assays about cell growth and proliferation showed that miR-155 knockdown led to a significant decrease in cell proliferation which was determined by MTT assay and colony formation assay compared to those of Lv-NC cells. Flow cytometry analysis showed that depletion of miR-155 could cause cell cycle change and the number of apoptotic cells was significantly increased in Lv-miR155 cells compared with control cells. In addition, the expression of several apoptosis-related factors were dramatically changed, such as PTEN, PIP₃, AKT, p-AKT, Bax and Bcl-2. Our findings indicate that down-regulation of miR-155 significantly inhibits proliferation, migration, invasion and promotes apoptosis through PTEN singaling pathway in psoriasis cells. miR-155 might function as an oncogene miRNA in the progress of psoriasis.

[Pathogenesis of psoriasis]

Psoriasis is an inflammatory T cell-mediated autoimmune disease of skin and joints that affects 2-4 % of the adult population and 0.1-1 % of children. Genetic susceptibility, environmental triggering factors, and innate immune processes initiate psoriasis pathogenesis that results in an adaptive autoreactive response. The T cell response is orchestrated by CD 8(+) T cells in the epidermis and by CD 4(+) T cells in the dermis that predominantly produce interleukin-17 (IL‑17). Research of the past 15 years unraveled cellular and molecular mechanisms as well as cytokines like TNF-α or IL‑23 that contribute to psoriatic inflammation. This knowledge has been translated into clinical practice and a number of antipsoriatic small molecules and immunobiologics are now available. Here, we discuss the current principles of psoriasis pathogenesis in the context of modern therapies.

Extracellular MicroRNA Signature of Human Helper T Cell Subsets in Health and Autoimmunity

Upon T cell receptor stimulation, CD4⁺ T helper (Th) lymphocytes release extracellular vesicles (EVs) containing microRNAs. However, no data are available on whether human CD4⁺ T cell subsets release EVs containing different pattern of microRNAs. The present work aimed at filling this gap by assessing the microRNA content in EVs released upon in vitro T cell receptor stimulation of Th1, Th17, and T regulatory (Treg) cells. Our results indicate that EVs released by Treg cells are significantly different compared with those released by the other subsets. In particular, miR-146a-5p, miR-150-5p, and miR-21-5p are enriched, whereas miR-106a-5p, miR-155-5p, and miR-19a-3p are depleted in Treg-derived EVs. The in vitro identified EV-associated microRNA signature was increased in serum of autoimmune patients with psoriasis and returned to healthy levels upon effective treatment with etanercept, a biological drug targeting the TNF pathway and suppressing inflammation. Moreover, Gene Set Enrichment Analysis showed an over-representation of genes relevant for T cell activation, such as CD40L, IRAK1, IRAK2, STAT1, and c-Myb in the list of validated targets of Treg-derived EV miRNAs. At functional level, Treg-derived (but not Th1/Th17-derived) EVs inhibited CD4⁺ T cell proliferation and suppressed two relevant targets of miR-146a-5p: STAT1 and IRAK2. In conclusion, our work identified the miRNAs specifically released by different human CD4⁺ T cell subsets and started to unveil the potential use of their quantity in human serum to mark the pathological elicitation of these cells in vivo and their biological effect in cell to cell communication during the adaptive immune response.

Cannabinoids: Possible agents for treatment of psoriasis via suppression of angiogenesis and inflammation

Psoriasis is a chronic skin disease also affecting other sites such as joints. This disease highly depends on inflammation and angiogenesis as well as other pathways. At each step of the psoriasis molecular pathway, different inflammatory cytokines and angiogenic growth factors are involved such as hypoxia inducible factor-1 α (HIF-1 α), vascular endothelial growth factor (VEGF), matrix metalo proteinases (MMPs), basic fibroblast growth factor (bFGF), Angiopoitin-2, interleukin-8 (IL-8), IL-17, and IL-2. Beside the mentioned growth factors and cytokines, cellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) which play roles in both angiogenesis and inflammation are also involved in the pathogenesis. Cannabinoids are active compounds of Cannabina Sativa inducing their effects through cannabinoid receptors (CBs). JWH-133 is a synthetic cannabinoid with strong anti-angiogenic and anti-inflammatory activities. This agent is able to inhibit HIF-1 α, VEGF, MMPs, bFGF, IL-8, IL-17, and other mentioned cytokines and adhesion molecules both in vivo and in vitro. Altogether, authors suggest using this cannabinoid for treatment of psoriasis due to its potential in suppressing the two main steps of psoriatic pathogenesis. Of course complementary animal studies and human trials are still required.

High throughput sequencing reveals the diversity of TRB-CDR3 repertoire in patients with psoriasis vulgaris

Psoriasis is a T cell-mediated chronic inflammatory skin disease with inflammatory cell infiltrates in the dermis and epidermis. Previous studies suggested that there are some expanded T-cell receptor (TCR) clones in psoriatic skin. However, the effect of psoriasis on the immunological characteristics of TCR in circulating blood has not been reported. To address this, we performed high-throughput sequencing to reveal the immunological characteristics of TCR beta chain (TRB) in both psoriasis patients and healthy controls. Our results revealed that the TRB-CDR3 region of psoriasis patients had distinctive immunological characteristics compared with that of healthy controls, including V gene usage, nt of N addition. In addition, three types of TRB-CDR3 peptides were found highly relevant to psoriasis. Our findings show the comprehensive characteristics of psoriasis on the TRB-CDR3 repertoire of circulating blood at sequence-level resolution. These findings may contribute to a better understanding of the pathogenesis of psoriasis and open opportunities to explore potential therapeutic targets.

NADPH Oxidase-Derived Superoxide Provides a Third Signal for CD4 T Cell Effector Responses

Originally recognized for their direct induced toxicity as a component of the innate immune response, reactive oxygen species (ROS) can profoundly modulate T cell adaptive immune responses. Efficient T cell activation requires: signal 1, consisting of an antigenic peptide-MHC complex binding with the TCR; signal 2, the interaction of costimulatory molecules on T cells and APCs; and signal 3, the generation of innate immune-derived ROS and proinflammatory cytokines. This third signal, in particular, has proven essential in generating productive and long-lasting immune responses. Our laboratory previously demonstrated profound Ag-specific hyporesponsiveness in the absence of NADPH oxidase-derived superoxide. To further examine the consequences of ROS deficiency on Ag-specific T cell responses, our laboratory generated the OT-II.Ncf1(m1J) mouse, possessing superoxide-deficient T cells recognizing the nominal Ag OVA323-339 In this study, we demonstrate that OT-II.Ncf1(m1J) CD4 T cells displayed a severe reduction in Th1 T cell responses, in addition to blunted IL-12R expression and severely attenuated proinflammatory chemokine ligands. Conversely, IFN-γ synthesis and IL-12R synthesis were rescued by the addition of exogenous superoxide via the paramagnetic superoxide donor potassium dioxide or superoxide-sufficient dendritic cells. Ultimately, these data highlight the importance of NADPH oxidase-derived ROS in providing a third signal for adaptive immune maturation by modulating the IL-12/IL-12R pathway and the novelty of the OT-II.Ncf1(m1J) mouse model to determine the role of redox-dependent signaling on effector responses. Thus, targeting ROS represents a promising therapeutic strategy in dampening Ag-specific T cell responses and T cell-mediated autoimmune diseases, such as type 1 diabetes.

Gluten-free diet does not influence the occurrence and the Th1/Th17-Th2 nature of immune-mediated diseases in patients with coeliac disease

INTRODUCTION

Coeliac disease (CD) is the most common Th1-mediated enteropathy, frequently associated with other immune-mediated disorders (IMD).

AIMS

To evaluate: (1) the prevalence of IMD at the time of and after CD diagnosis; (2) a possible change in immune response to gluten free diet (GFD); (3) the potential role of GFD in reducing and/or preventing IMD in CD.

METHODS

Prospective study including all consecutive adult CD patients who underwent investigations for Th1-Th17/Th2-IMD at the time of CD diagnosis and after a 5-year follow-up period.

RESULTS

1255 CD were enrolled. Of these, 257 patients (20.5%) showed IMD at the time of CD diagnosis, with 58.4% presenting a Th1/Th17-IMD. After a 5-year follow-up period, 682 patients (54.3%) showed new IMD despite GFD. Of these, 57.3% presented a Th1/Th17-IMD and 42.7% a Th2-IMD (p=0.8). When compared the prevalence of each type of IMD before and after CD diagnosis, we did not identify any significant "switch" from Th1/Th17- to Th2-IMD or vice versa. The number of patients with Th1/Th17- and/or Th2-IMD increased during the GFD period (20.5% vs 54.3%; p<0.01; OR 1.9).

CONCLUSIONS

The prevalence of IMD at the time of CD diagnosis is high and it seems to increase in the follow-up period despite GFD.

Influence of different types of contact hypersensitivity on imiquimod-induced psoriasis-like inflammation in mice

It is currently believed that psoriasis and allergic contact dermatitis (ACD) are different diseases; however, they share clinical similarities. The involvement of T helper 17 (Th17) cells in these disorders provides a novel opportunity to investigate the relationship between them. The present study aimed to determine whether the same or overlapping inflammatory pathways are involved in the two diseases, and the influence of different types of ACD on psoriasis. Compound mouse models of Th1 or Th2‑type contact hypersensitivity (CHS) combined with imiquimod (IMQ)‑induced psoriasis‑like inflammation were established, in order to mimic the characteristics of ACD and psoriasis. Histopathology, immunohistochemistry and cytokine detection in blood serum and tissues were used to compare the differences between the mice treated with IMQ alone or IMQ combined with Th1 and Th2‑type CHS. As compared with the IMQ‑treated mice or IMQ-treated Th1‑type CHS mice, the mice with Th2‑type CHS treated with IMQ exhibited more serious psoriasis‑like inflammation with increased epidermal thickness and infiltrating cells in the derma. High mRNA expression levels of interleukin (IL)‑17, IL‑22, IL‑23, TNF‑α and RORγt were detected in back skin lesions. Additionally, high levels of IL‑17 and IL‑22 in blood serum were detected in IMQ‑treated mice combined with Th2‑type CHS. The mice treated with IMQ alone, and IMQ treatment combined with Th1‑type CHS had a comparable psoriasis‑like inflammatory response in the back skin. In conclusion, these data demonstrate that Th2‑type CHS exacerbated the IMQ‑treated psoriatic inflammation of mice via the IL‑23/IL‑17 axis. Th17 cells and associated pathways may link ACD and psoriasis. Therefore, patients with psoriasis should avoid contact with specific sensitizers, such as fragrance and rubber products, which may induce Th2 polarization.

Downregulation of RUNX3 moderates the frequency of Th17 and Th22 cells in patients with psoriasis

Psoriasis is a common chronic inflammatory and T cell-meditated skin disease. Runt-related transcription factor 3 (RUNX3), one of the runt-domain family of transcription factors, has been reported to be a susceptibility gene for psoriasis. The present study was designed to delineate the role and underlying mechanism of RUNX3 involved in the differentiation of T helper (Th) 17 and Th22 cells in psoriasis. The results of the present study demonstrated that the expression of RUNX3 increased significantly in CD4-positive (CD4⁺) T cells from patients with psoriasis, compared with healthy controls. In addition, increased levels of interleukin (IL)-6, IL-20 and IL-22, and increased frequencies of Th17 and Th22 cells were found in the patients with psoriasis patients, compared with the healthy controls. It was also found that the overexpression of RUNX3 increased the levels of Th17- and Th22-associated cytokines in the CD4⁺ T cells from the healthy controls. However, the inhibition of RUNX3 reduced the levels of the associated cytokines and decreased the frequency of Th17 and Th22 cells in the CD4⁺ T cells from the patients with psoriasis. Taken together, the present study suggested that RUNX3 regulated the differentiation of Th17 and Th22 cells in psoriasis, providing a promising therapeutic strategy for the treatment of psoriasis.

Inhibition of imiquimod-induced psoriasis-like dermatitis in mice by herbal extracts from some Indian medicinal plants

Psoriasis is a chronic autoimmune human skin disorder that is characterized by excessive proliferation of keratinocytes, scaly plaques, severe inflammation and erythema. The pathophysiology of psoriasis involves interplay between epidermal keratinocytes, T lymphocytes, leukocytes and vascular endothelium. Increased leukocyte recruitment and elevated levels of cytokines, growth factors and genetic factors like interleukin (IL)-1β, IL-6, IL-17, IL-22, IL-23, tumour necrosis factor (TNF)-α, interferon (IFN)-γ, transforming growth factor (TGF)-β, toll-like receptor (TLR)-2, signal transducer and activator of transcription (STAT-3), 15-lipoxygenase (LOX)-2, coiled-coil alpha-helical rod protein 1 (CCHCR1), steroidogenic acute regulatory protein (StAR) and vitamin D receptor (VDR) are the most critical factors governing the exacerbation of psoriasis. In the present study, an attempt was made to elucidate the preventive role of herbal extracts of four dermo-protective Ayurvedic plants, Tinospora cordifolia (TC), Curcuma longa (CL), Celastrus paniculatus (CP) and Aloe vera (AV), against psoriasis-like dermatitis. Parkes (P) strain mice were initially induced with psoriasis-like dermatitis using topical application of imiquimod (IMQ, 5 %), followed by subsequent treatment with the herbal extracts to examine their curative effect on the psoriasis-like dermatitis-induced mice. The extracts were orally/topically administered to mice according to their ED/LD50 doses. Phenotypical observations, histological examinations, and semi-quantitative reverse transcription PCR (RT-PCR) analyses of the skin and blood samples of the control, IMQ-treated and herbal extract-treated psoriasis-like dermatitis-induced mice lead to the conclusion that the combination extract from all the plants was instrumental in downregulating the overexpressed cytokines, which was followed by the CL extract. Moreover, lesser yet positive response was evident from CP and TC extracts. The results suggest that these plants can prove to have tremendous preventive potential against the disease and can open the way to new therapeutic strategies for psoriasis treatment.

Recent advances in the biomedical applications of fumaric acid and its ester derivatives: The multifaceted alternative therapeutics

Several lines of evidence have demonstrated the potential biomedical applications of fumaric acid (FA) and its ester derivatives against many human disease conditions. Fumaric acid esters (FAEs) have been licensed for the systemic treatment of the immune-mediated disease psoriasis. Biogen Idec Inc. announced about the safety and efficacy of the formulation FAE (BG-12) for treating RRMS (relapsing-remitting multiple sclerosis). Another FAE formulation DMF (dimethyl fumarate) was found to be capable of reduction in inflammatory cardiac conditions, such as autoimmune myocarditis and ischemia and reperfusion. DMF has also been reported to be effective as a potential neuroprotectant against the HIV-associated neurocognitive disorders (HAND). Many in vivo studies carried out on rat and mice models indicated inhibitory effects of fumaric acid on carcinogenesis of different origins. Moreover, FAEs has emerged as an important matrix ingredient in the fabrication of biodegradable scaffolds for tissue engineering applications. Drug delivery vehicles composed of FAEs have shown promising results in delivering some leading drug molecules. Apart from these specific applications and findings, many more studies on FAEs have revealed new therapeutic potentials with the scope of clinical applications. However, until now, this scattered vital information has not been written into a collective account and analyzed for minute details. The aim of this paper is to review the advancement made in the biomedical application of FA and FAEs and to focus on the clinical investigation and molecular interpretation of the beneficial effects of FA and FAEs.

Update on the treatment of psoriasis and psoriatic arthritis - role of apremilast

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis (PsO). The treatment of PsA can be challenging and includes non-steroidal anti-inflammatory drugs, synthetic disease modifying antirheumatic drugs, and biologicals. One novel oral compound that has been recently established for the treatment of PsO and PsA is apremilast, a small molecule PDE4 inhibitor. The inhibition of PDE4 results in increased intracellular cAMP levels and modulates the expression of inflammatory mediators critically involved in PsO and PsA pathogenesis like TNF, IL-12, IL-17, and IL-23. Apremilast received US Food and Drug Administration approval for the treatment of PsO and PsA in 2014 and received approval from the European Medicines Agency in early 2015. This article summarizes the pharmacology of apremilast, its efficacy and safety in clinical studies, and its potential position in modern PsO/PsA management.