Importance of regulatory T cells in the pathogenesis of psoriasis: review of the literature

Dexamethasone-loaded fibroin nanoparticles promote retinal reattachment in rats by regulating the Th17/Treg balance

Retinal detachment (RD) is a common acute blinding eye disease, and dexamethasone (DEX), an adrenocorticosteroid, shows protective effects against RD. However, its poor water solubility and low bioavailability limit its effectiveness. To address this, we developed SF@DEX nanomaterials and investigated their therapeutic potential and mechanisms in RD. The nanomaterials were successfully synthesized and characterized, achieving 90% encapsulation efficiency and releasing 60% of DEX within 12 h.In vitro, phagocytosis was measured by flow cytometry, and enzyme-linked immunosorbent assay determined interleukin-17 (IL-17) and interleukin-10 (IL-10) levels. A rat RD model was established surgically, followed by oral administration of silk fibroin (SF), SF@DEX, and DEX. Polymerase chain reaction (PCR) assessed IL-17A and forkhead box P3 (FOXP3) expression, while Western blot analysed transforming growth factor-β1 (TGF-β1), IL-10, IL-17A, and FOXP3 levels. Apoptosis of retinal ganglion cells was evaluated using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and confocal microscopy detected colocalization of IL-17A and FOXP3. SF@DEX treatment significantly reduced Th17 cells and IL-17A while increasing Tregs, FOXP3, TGF-β1, and IL-10 levels. The severity of RD in rats was notably alleviated by SF@DEX, demonstrating its anti-inflammatory effects through modulation of the Th17/Treg immune balance. These results highlight SF@DEX as a promising nano-based therapy for RD.

Modulation of Plet1 expression by N-Acetylglucosamine through the IL-17 A-MAPK pathway in an imiquimod-induced psoriasis mouse model

Psoriasis (Ps) is a chronic inflammatory disorder marked by skin plaque formation, driven by immune dysregulation and genetic factors. Despite the available treatments, incidence of Ps is increasing in the dermatology patients. Novel strategies are crucial due to current treatment limitations. The interleukin 17 (IL-17) pathway is pivotal in Ps pathogenesis, however the expression of its putative target gene placenta expressed transcript 1 (Plet1) remains unstudied in Ps. Considering the potential anti-inflammatory properties of N-Acetylglucosamine (GlcNAc), our study explored its role in modulating Plet1 expression in an imiquimod (IMQ)-induced Ps mouse model. Our data demonstarted a significant reduction of inflammation and Psoriasis Area and Severity Index (PASI) scores, downregulation of growth factors (GFs), IL-17 A, and MAPK expression after GlcNAc treatment. In addition, GlcNAc treatment reduced neutrophils, monocyte-dendritic cells (Mo-DC) and conventional T cells (Tcons) while increasing monocyte-macrophages (Mo-Macs) and regulatory T cells (Tregs). GlcNAc treatment also downregulated Plet1 overexpression in psoriatic mouse skin and in vitro, reduced proliferation and apoptosis in IL-17 A stimulated human dermal fibroblasts (HDF), along with IL-17 A and TGF-β mRNA expression. Together, these data suggest that, GlcNAc interferes with downstream mechanisms in IL-17 pathway and downregulating Plet1 expression, presenting a promising strategy for Ps treatment.

Supersaturation as a Galenic Concept for Improving the Cutaneous Bioavailability of Drugs in Topical Therapy

The essential force that allows an epicutaneously applied drug to penetrate the skin is mediated by diffusion. The physicochemical properties of the skin tissue at the site of application and the concentration gradient of the dissolved drug between the vehicle and the stratum corneum are decisive here. One way to specifically improve these diffusion conditions is to use supersaturation. This uses the physical principle of the difference between the solubility curve and precipitation curve (Ostwald-Miers range). During the conversion of the application vehicle into the segregation vehicle, supersaturation of the dissolved drug substance in a solvent is achieved by evaporation, e.g., of a solubilizer. In principle, the change in solubility can also be achieved by heating and then cooling a solution. This principle has already been realized in a formulation of a fixed combination of calcipotriol and betamethasone dipropionate, two lipophilic drugs susceptible to hydrolysis, and is available on the market as a spray foam.

Nilotinib-induced elephantine psoriasis in a chronic myeloid leukemia patient: A rare case report and literature review

Tyrosine kinase inhibitors are anticancer drugs that disrupt signal transduction pathways in protein kinases by different mechanisms. This group of pharmacologic agents has significantly improved the outcome of patients with chronic myeloid leukemia. However, their effect is not limited to cancer cells, and various complications, particularly cutaneous reactions, have been reported. We report a very rare case of a 35-year-old female with a history of chronic myeloid leukemia who presented with elephantine psoriasis after the treatment with nilotinib.

Conclusions: This case highlights a critical side effect of tyrosine kinase inhibitors. Awareness of this subject can be useful for better management of similar patients.

Investigation of the role of IL18, IL-1β and NLRP3 inflammasome in reducing expression of FLG-2 protein in Psoriasis vulgaris skin lesions

We investigated the effects of the NACHT leucine-rich repeat- and PYD-containing proteins (NLRP3) inflammasome, interleukin -18 (IL-18) and interleukin-1 beta (IL-1β) cytokines on the expression of filaggrin-2 (FLG-2) protein in psoriasis patients. Peripheral blood mononuclear cells (PBMC), including T cells, were isolated from psoriasis patients and healthy donors. Ribonucleic acid (RNA) extraction and reverse transcription-polymerase chain reaction (RT-PCR) were performed for all specimens. Immunohistochemical analysis for FLG-2 in normal and psoriatic epidermal tissue also was performed. Western blot was used to separate and identify FLG-2 protein, and immunohistochemical staining was performed to assess FLG-2 expression for psoriasis skin lesions and normal skin. RT-PCR analysis indicated that NLRP3 inflammasome, IL-18 cytokine and IL-1β cytokine expression were increased in psoriatic epidermis compared to normal skin. We found that the expression of FLG-2 was decreased in psoriatic epidermis compared to normal skin. Higher levels of NLRP3 help decrease the FLG-2 level.

Oral and Topical Vitamin D, Sunshine, and UVB Phototherapy Safely Control Psoriasis in Patients with Normal Pretreatment Serum 25-Hydroxyvitamin D Concentrations: A Literature Review and Discussion of Health Implications

Vitamin D, sunshine and UVB phototherapy were first reported in the early 1900s to control psoriasis, cure rickets and cure tuberculosis (TB). Vitamin D also controlled asthma and rheumatoid arthritis with intakes ranging from 60,000 to 600,000 International Units (IU)/day. In the 1980s, interest in treating psoriasis with vitamin D rekindled. Since 1985 four different oral forms of vitamin D (D2, D3, 1-hydroxyvitaminD3 (1(OH)D3) and 1,25-dihydroxyvitaminD3 (calcitriol)) and several topical formulations have been reported safe and effective treatments for psoriasis-as has UVB phototherapy and sunshine. In this review we show that many pre-treatment serum 25(OH)D concentrations fall within the current range of normal, while many post-treatment concentrations fall outside the upper limit of this normal (100 ng/mL). Yet, psoriasis patients showed significant clinical improvement without complications using these treatments. Current estimates of vitamin D sufficiency appear to underestimate serum 25(OH)D concentrations required for optimal health in psoriasis patients, while concentrations associated with adverse events appear to be much higher than current estimates of safe serum 25(OH)D concentrations. Based on these observations, the therapeutic index for vitamin D needs to be reexamined in the treatment of psoriasis and other diseases strongly linked to vitamin D deficiency, including COVID-19 infections, which may also improve safely with sufficient vitamin D intake or UVB exposure.

The Therapeutic Potential of Regulatory T Cells: Challenges and Opportunities

Regulatory T cells (Tregs) are an immunosuppressive subgroup of CD4+ T cells which are identified by the expression of forkhead box protein P3 (Foxp3). The modulation capacity of these immune cells holds an important role in both transplantation and the development of autoimmune diseases. These cells are the main mediators of self-tolerance and are essential for avoiding excessive immune reactions. Tregs play a key role in the induction of peripheral tolerance that can prevent autoimmunity, by protecting self-reactive lymphocytes from the immune reaction. In contrast to autoimmune responses, tumor cells exploit Tregs in order to prevent immune cell recognition and anti-tumor immune response during the carcinogenesis process. Recently, numerous studies have focused on unraveling the biological functions and principles of Tregs and their primary suppressive mechanisms. Due to the promising and outstanding results, Tregs have been widely investigated as an alternative tool in preventing graft rejection and treating autoimmune diseases. On the other hand, targeting Tregs for the purpose of improving cancer immunotherapy is being intensively evaluated as a desirable and effective method. The purpose of this review is to point out the characteristic function and therapeutic potential of Tregs in regulatory immune mechanisms in transplantation tolerance, autoimmune diseases, cancer therapy, and also to discuss that how the manipulation of these mechanisms may increase the therapeutic options.

Regulatory T Cell Plasticity and Stability and Autoimmune Diseases

CD4⁺CD25⁺ regulatory T cells (Tregs) are a class of CD4⁺ T cells with immunosuppressive functions that play a critical role in maintaining immune homeostasis. However, in certain disease settings, Tregs demonstrate plastic differentiation, and the stability of these Tregs, which is characterized by the stable expression or protective epigenetic modifications of the transcription factor Foxp3, becomes abnormal. Plastic Tregs have some features of helper T (Th) cells, such as the secretion of Th-related cytokines and the expression of specific transcription factors in Th cells, but also still retain the expression of Foxp3, a feature of Tregs. Although such Th-like Tregs can secrete pro-inflammatory cytokines, they still possess a strong ability to inhibit specific Th cell responses. Therefore, the plastic differentiation of Tregs not only increases the complexity of the immune circumstances under pathological conditions, especially autoimmune diseases, but also shows an association with changes in the stability of Tregs. The plastic differentiation and stability change of Tregs play vital roles in the progression of diseases. This review focuses on the phenotypic characteristics, functions, and formation conditions of several plastic Tregs and also summarizes the changes of Treg stability and their effects on inhibitory function. Additionally, the effects of Treg plasticity and stability on disease prognosis for several autoimmune diseases were also investigated in order to better understand the relationship between Tregs and autoimmune diseases.

Homocysteine and psoriasis

Psoriasis is caused by a complex interplay among the immune system, genetic background, autoantigens, and environmental factors. Recent studies have demonstrated that patients with psoriasis have a significantly higher serum homocysteine (Hcy) level and a higher prevalence of hyperhomocysteinaemia (HHcy). Insufficiency of folic acid and vitamin B₁₂ can be a cause of HHcy in psoriasis. Hcy may promote the immuno-inflammatory process in the pathogenesis of psoriasis by activating Th1 and Th17 cells and neutrophils, while suppressing regulatory T cells. Moreover, Hcy can drive the immuno-inflammatory process by enhancing the production of the pro-inflammatory cytokines in related to psoriasis. Hcy can induce nuclear factor kappa B activation, which is critical in the immunopathogenesis of psoriasis. There may be a link between the oxidative stress state in psoriasis and the effect of HHcy. Hydrogen sulfide (H₂S) may play a protective role in the pathogenesis of psoriasis and the deficiency of H₂S in psoriasis may be caused by HHcy. As the role of Hcy in the pathogenesis of psoriasis is most likely established, Hcy can be a potential therapeutic target for the treatment of psoriasis. Systemic folinate calcium, a folic acid derivative, and topical vitamin B12 have found to be effective in treating psoriasis.

Narrow-band phototherapy and sodium salt of the synthetic diamide gamma-D-glutamyl-D-tryptophan as a combined method of psoriasis treatment: comprehensive and comparative evaluation

The paper presents the results of a comparative study of various immunosuppressive treatment methods of medium severity vulgar psoriasis (PASI from 10 to 20). The parameters used were PASI indices, p53 apoptosis marker expression indices, and expression indices of T-regulatory cell marker Foxp3. The study involved 96 patients, from 18 to 60 years old, divided by randomization into three groups. Patients in the 1st group (n = 32) received narrow-band phototherapy according to a 4-day regimen. We used the Waldmann UV-7002K instrument and F79/120W-TL01 lamps generating radiation with a maximum emission at a wavelength of 311 nm. We started with a dose of 0.05–0.1 J/cm2, subsequently increased by 0.05–0.1 J/cm2 for each procedure, in the absence of erythema. In total, patients received 12–15 procedures, with a course dose of 4.7–7.65 J/cm2. In the 2nd group (n = 32), patients were treated with the sodium salt of the synthetic gamma-D-glutamyl-D tryptophan dipeptide. Patients of the 3rd group (n = 32) underwent combination therapy, which included both methods described above. As a result of treatment, the greatest decrease in the PASI index, as well as the level of expression of the marker of Foxp3 T-regulatory cells, was observed among patients who received the combined regimen. The data obtained indicate the high therapeutic efficacy of narrow-band phototherapy in combination with the sodium salt of the synthetic gamma-D glutamyl-D tryptophan synthetic dipeptide. It was also noted that the immunohistochemical marker p53, reflecting the cellular renewal of psoriatic papule keratinocytes, is an informative molecular-cellular indicator of the effectiveness of narrow-band phototherapy.

(R)-Salbutamol Improves Imiquimod-Induced Psoriasis-Like Skin Dermatitis by Regulating the Th17/Tregs Balance and Glycerophospholipid Metabolism

Psoriasis is a skin disease that is characterized by a high degree of inflammation caused by immune dysfunction. (R)-salbutamol is a bronchodilator for asthma and was reported to alleviate immune system reactions in several diseases. In this study, using imiquimod (IMQ)-induced mouse psoriasis-like dermatitis model, we evaluated the therapeutic effects of (R)-salbutamol in psoriasis in vivo, and explored the metabolic pathway involved. The results showed that, compared with IMQ group, (R)-salbutamol treatment significantly ameliorated psoriasis, reversed the suppressive effects of IMQ on differentiation, extreme keratinocyte proliferation, and infiltration of inflammatory cells. Enzyme-linked immunosorbent assays (ELISA) showed that (R)-salbutamol markedly reduced the plasma levels of IL-17. Cell analysis using flow cytometry showed that (R)-salbutamol decreased the proportion of CD4+ Th17+ T cells (Th17), whereas it increased the percentage of CD25+ Foxp3+ regulatory T cells (Tregs) in the spleens. (R)-salbutamol also decreased the weight ratio of spleen to body. Furthermore, untargeted metabolomics showed that (R)-salbutamol affected three metabolic pathways, including (i) arachidonic acid metabolism, (ii) sphingolipid metabolism, and (iii) glycerophospholipid metabolism. These results demonstrated that (R)-salbutamol can alleviate IMQ-induced psoriasis through regulating Th17/Tregs cell response and glycerophospholipid metabolism. It may provide a new use of (R)-salbutamol in the management of psoriasis.

Abnormal numbers of CD4+ T lymphocytes and abnormal expression of CD4+ T lymphocyte‑secreted cytokines in patients with immune‑related haemocytopenia

In the past decade, a group of cases with persisting haemocytopenia were separated from those with idiopathic cytopenia of undetermined significance due to the optimal response of these patients to immunosuppression therapy and due to the detection of autoantibodies in the bone marrow of haemopoietic cells. This condition was termed immune-related haemocytopenia (IRH). However, the quantity of T lymphocytes remained unknown. In the present study, the percentage of CD4⁺ T-cell subsets and related cytokines was measured using flow cytometry and an enzyme-linked immunosorbent assay. An abnormal number of CD4⁺ T cell subsets was found, including increased percentages of T helper (Th)2, Th9 and Th17 cells and a decreased number of regulatory T (Treg) cells. In addition, the results showed downregulation in the levels of interleukin (IL)-2, transforming growth factor-β and IL-35, and upregulation in the levels of IL-4, IL-6, IL-17, IL-23 and interferon-γ in patients who did not receive therapy (untreated patients). These levels were significantly associated with the number of peripheral blood cells and were recovered following treatment. In conclusion, an abnormal number of CD4⁺ T cell subsets and corresponding abnormal levels of regulatory cytokines resulted in the stimulation of B1 lymphocytes to produce autoantibodies in IRH, which may be considered as markers to evaluate disease prognosis and treatment strategies.

Th1, Th17, and Treg Responses are Differently Modulated by TNF-α Inhibitors and Methotrexate in Psoriasis Patients

Psoriasis is a chronic, recurrent, immune-mediated, hyperproliferative inflammatory skin disease. The role of the adaptive immune system, particularly of Th1 and Th17 lymphocytes, has been regarded as prominent in the immunopathogenesis of psoriasis, as well as decreased Tregs function. Immunobiological drugs were administered in therapeutic pulses and a few studies evaluate their effects on the immune repertoire. The aim of this study was to evaluate the adaptive immune profile of patients with severe psoriasis under immunobiological treatment in two time points. Thirty-two psoriasis patients and 10 control patients were evaluated. In the group of psoriasis patients, 10 patients were on anti-TNF and 14 patients on methotrexate treatment, while 8 individuals were not treated. IL-17, IFN-γ, TNF-α, IL-6, IL-2, and IL-10 were analyzed. CD4 T cell intracellular cytokines were analyzed. It was observed that stimulation could significantly increase the production of IL-17, IFN-γ, TNF-α, and IL-10 only before anti-TNF pulse therapy. The activation of Th1 and Treg cells after stimulation was significantly higher before anti-TNF pulse. Patients on methotrexate or anti-TNF therapy produced significantly lower levels of TNF-α, IL-10, and IL-6. Furthermore, these patients showed a significant decrease in the activated CD4+ T cells. The treatment with immunomodulator or methotrexate modulates the activation of CD4+ T cells, and anti-TNF treatment appears to have a modulating effect on the activation and production of Th1, Th17, and Treg cells.

Pharmacokinetics and Safety of Icotinib Hydrochloride Cream in Patients with Mild to Moderate Chronic Plaque Psoriasis: A Randomized Double-Blind Vehicle-Controlled Phase 1 Study

OBJECTIVE

This phase I study aimed to systematically assess the safety, local tolerability, pharmacokinetics, and preliminary efficacy of topical icotinib hydrochloride cream in patients with mild to moderate plaque psoriasis.

MATERIALS AND METHODS

Eligible Chinese adult patients with mild to moderate psoriasis were assigned to the icotinib cream or vehicle group. Icotinib cream with increasing concentrations (0.5%, 1.0%, 2.0%, and 4.0%) or vehicle were administered by the fingertip unit method to the skin lesions twice a day for 4 weeks. Safety assessments included the incidence and severity of adverse events (AEs), local tolerability at the treatment area, vital signs, and laboratory examinations. Plasma levels of icotinib were also measured for the pharmacokinetics calculation. The efficacy was preliminarily explored by assessing the improvement in the severity level using Target Plaque Severity Score (TPSS) and overall improvement using the Psoriasis Area Severity Index (PASI) and Dermatological Quality Life Index.

RESULTS

Forty-one patients were enrolled and qualified for safety analysis. 27 (65.9%) patients experienced at least one AE, of which application-site adverse drug reactions (ADRs) were reported in 6 (14.6%) patients. All ADRs were of grade 1 or 2, most common irritation (4.5%), itching (3.1%), and erythema (2.4%), and resolved during follow-up. The systemic exposure to icotinib was very low; the highest plasma concentration was 0.214 ng/mL, while the area under the curve from 0 to 12 hours was 1.626 h·ng/mL. The TPSS improved for all icotinib groups after treatment in a dose- and time-dependent manner.

CONCLUSION

This phase 1 study demonstrated favorable safety, tolerable toxicity, and preliminary efficacy of icotinib cream in patients with mild to moderate psoriasis. The dose concentration of 2.0% (twice daily based on the fingertip unit method) is recommended for further study.

STUDY DESIGN

This is a single-center, randomized, double-blind, and vehicle-controlled study.

MiR-548a-3p Promotes Keratinocyte Proliferation Targeting PPP3R1 after Being Induced by IL-22

Psoriasis is an immune-mediated chronic skin disorder where T cells play a main role, and numerous inflammatory cytokines are implicated in its pathogenesis by initiating keratinocyte proliferation. Interleukin-22 (IL-22), an IL-10 family cytokines, is critical in the pathogenesis and development of psoriasis. To determine the target of microRNA (miR) -548a-3p and investigate its role in keratinocyte proliferation after treating human keratinocytes (HaCaT) with IL-22, we used quantitative reverse transcriptase PCR to measure the expression of miR-548a-3p in both HaCaT cells stimulated with IL-22 and psoriatic lesions, and then detected the biological function of miR-548a-3p in HaCaT cells by performing Counting Kit-8 (CCK-8) assays. Luciferase reporter assay was conducted to determine the target gene of miR-548a-3p. Immunohistochemistry and Western blot were performed to verify the target gene. Results showed that miR-548a-3p was significantly upregulated both in HaCaT cells treated with IL-22 and psoriatic lesions. The over expression of miR-548a-3p could promote the proliferation of HaCaT cells. Luciferase was mutated in the 3'UTR of PPP3R1, a gene coding Calcineurin. Immunohistochemistry and Western blot demonstrated that the expression of PPP3R1 decreased respectively in psoriatic lesions and HaCaT cells. In conclusion, the expression of miR-548a-3p is upregulated in IL-22 mediated keratinocyte proliferative disorder like psoriasis. The impact of miR-548a-3p on keratinocyte proliferation may be implemented by targeting PPP3R1 and T regulatory cells may be involved in the pathogenesis of psoriasis.

PSORI-CM02 Formula Increases CD4+ Foxp3+ Regulatory T Cell Frequency and Ameliorates Imiquimod-Induced Psoriasis in Mice

Psoriasis is an autoimmune and inflammatory disease, which is estimated to affect 2-3% of the population in the world. PSORI-CM02 is an empirical formula of Chinese medicine optimized from Yin Xie Ling, which is widely used to treat psoriasis in China for decades. However, its antipsoriatic mechanisms are still not well understood. Here, we explored the therapeutic effects of PSORI-CM02 on psoriasis and its mechanisms of action in imiquimod-induced psoriasis-like mouse models and human HaCaT cells. In experiments in vitro, PSORI-CM02 significantly inhibited HaCaT cell proliferation in dose-dependent and time-dependent manners. Furthermore, it hindered the progression of HaCaT cell cycle and arrested HaCaT cells at G1 phase. On the other hand, our in vivo studies demonstrated that PSORI-CM02 dramatically reduced psoriasis area and severity index scores and lesion temperature in imiquimod-induced psoriatic mice. The antioxidative activities of glutathione, catalase, and superoxide dismutase were increased while oxidative activity of malonaldehyde was markedly decreased after treatments with PSORI-CM02. PSORI-CM02 also suppressed the mRNA expression of proinflammatory cytokines, including TNF-α, IL-6, and IL-17, and lowered their protein levels in the serum as well. In addition, PSORI-CM02 could reduce the expression of IKKα and NF-κB in psoriatic skin tissue. It also upregulated the proportion of CD4+ Foxp3+ regulatory T cells (Tregs) in both lymph nodes and spleens and promoted CD4+ CD25+ Treg proliferation in vitro. Taken together, our research demonstrated that PSORI-CM02 inhibited HaCaT cell proliferation by arresting them at G1 phase and alleviated systemic inflammation and psoriasis in mice via altering the oxidative/anti-oxidative status, tipping the balance between Th17 responsiveness and CD4+ Foxp3+ Treg generation, and suppressing the expression of proinflammatory cytokines as well as NF-κB signaling.

The role of regulatory T cells and genes involved in their differentiation in pathogenesis of selected inflammatory and neoplastic skin diseases. Part II: The Treg role in skin diseases pathogenesis

Regulatory FOXP3+ T cells (Tregs) constitute 5% to 10% of T cells in the normal human skin. They play an important role in the induction and maintenance of immunological tolerance. The suppressive effects of these cells are exerted by various mechanisms including the direct cytotoxic effect, anti-inflammatory cytokines, metabolic disruption, and modulation of the dendritic cells function. The deficiency of Treg cells number or function are one of the basic elements of the pathogenesis of many skin diseases, such as psoriasis, atopic dermatitis, bacterial and viral infections. They also play a role in the pathogenesis of T cell lymphomas of the skin (cutaneous T cell lymphomas - CTCL), skin tumors and mastocytosis. Here, in the second part of the cycle, we describe dysfunctions of Tregs in selected skin diseases.

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.

Activated Circulating T Follicular Helper Cells Are Associated with Disease Severity in Patients with Psoriasis

Circulating T follicular helper (cTfh) cells are known to be involved in numerous immune-mediated diseases, but their pathological role in psoriasis is less fully investigated. Herein, we aimed to identify whether cTfh cells contributed to the pathogenesis of psoriasis. The frequency and function of cTfh cells were compared between patients with psoriasis vulgaris and healthy controls, and the infiltration of Tfh cells was detected between lesional and nonlesional skin tissues of psoriasis patients. Moreover, the dynamic change of cTfh cells before and after acitretin treatment was evaluated. Our results showed both increased frequency and activation (indicated by higher expression of ICOS, PD-1, HLA-DR, and Ki-67 and increased production of IL-21, IL-17, and IFN-γ) of cTfh cells in psoriasis patients. Compared with nonlesional skin tissues of psoriasis patients, the number of infiltrated Tfh cells was significantly increased in psoriasis lesions. In addition, positive correlations between the percentage of cTfh, functional markers on cTfh cells in peripheral blood and disease severity were noted. Furthermore, the frequency of cTfh cells and the levels of cytokines secreted by cTfh cells were all significantly decreased after 1-month treatment.

Characterization of Th17 and FoxP3(+) Treg Cells in Paediatric Psoriasis Patients

Psoriasis is one of the most common inflammatory skin conditions affecting both children and adults. Growing evidence indicates that T-helper 17 (Th17) cells and CD4(+) CD25(+) regulatory T (Treg) cells play an important role in the pathogenesis of psoriasis. However, the relationship between Th17 and Treg cells and their dynamic variations in paediatric psoriasis remain unclear. In this study, we found that both Th17 and FoxP3(+) Treg cells and the ratio of Th17 to Treg cell frequency in the peripheral circulation were increased in patients with paediatric psoriasis and were positively correlated with the disease severity. The function of Treg to suppress CD4(+) CD25(-) T cell proliferation and IFN-γ secretion was impaired during the onset of psoriasis. After disease remission, both the Th17 and Treg cell frequencies were decreased, and the suppressive function of the Treg cells was obviously restored. However, neither Treg cells from the disease onset nor those after remission can regulate IL-17 secretion by CD4(+) T cells. These findings will further our understanding of the associations between Th17 and Treg cells in paediatric psoriasis and their influence on disease severity.

Association between Psoriasis Vulgaris and Coronary Heart Disease in a Hospital-Based Population in Japan

Background

Psoriasis vulgaris is a chronic inflammatory skin disease with an immune-genetic background. It has been reported as an independent risk factor for coronary heart disease (CHD) in the United States and Europe. The purpose of this study was to investigate the association between psoriasis and CHD in a hospital-based population in Japan.

Methods

For 113,065 in-hospital and clinic patients at our institution between January 1, 2011 and January 1, 2013, the diagnostic International Classification of Diseases (ICD)-10 codes for CHD, hypertension, dyslipidemia, diabetes, and psoriasis vulgaris were extracted using the medical accounting system and electronic medical record, and were analyzed.

Results

The prevalence of CHD (n = 5,167, 4.5%), hypertension (n = 16,476, 14.5%), dyslipidemia (n = 9,236, 8.1%), diabetes mellitus (n = 11,555, 10.2%), and psoriasis vulgaris (n = 1,197, 1.1%) were identified. The prevalence of CHD in patients with hypertension, dyslipidemia, diabetes, and psoriasis vulgaris were 21.3%, 22.2%, 21.1%, and 9.0%, respectively. In 1,197 psoriasis patients, those with CHD were older, more likely to be male, and had more number of the diseases surveyed by ICD-10 codes. Multivariate analysis showed that psoriasis vulgaris was an independent associated factor for CHD (adjusted odds ratio [OR]: 1.27; 95% confidence interval [CI]: 1.01–1.58; p = 0.0404) along with hypertension (adjusted OR: 7.78; 95% CI: 7.25–8.36; p < 0.0001), dyslipidemia (adjusted OR: 2.35; 95% CI: 2.19–2.52; p < 0.0001), and diabetes (adjusted OR: 2.86; 95% CI: 2.67–3.06; p < 0.0001).

Conclusion

Psoriasis vulgaris was independently associated with CHD in a hospital-based population in Japan.

Molecular and Cellular Profiling of Scalp Psoriasis Reveals Differences and Similarities Compared to Skin Psoriasis

Scalp psoriasis shows a variable clinical spectrum and in many cases poses a great therapeutic challenge. However, it remains unknown whether the immune response of scalp psoriasis differs from understood pathomechanisms of psoriasis in other skin areas. We sought to determine the cellular and molecular phenotype of scalp psoriasis by performing a comparative analysis of scalp and skin using lesional and nonlesional samples from 20 Caucasian subjects with untreated moderate to severe psoriasis and significant scalp involvement and 10 control subjects without psoriasis. Our results suggest that even in the scalp, psoriasis is a disease of the inter-follicular skin. The immune mechanisms that mediate scalp psoriasis were found to be similar to those involved in skin psoriasis. However, the magnitude of dysregulation, number of differentially expressed genes, and enrichment of the psoriatic genomic fingerprint were more prominent in skin lesions. Furthermore, the scalp transcriptome showed increased modulation of several gene-sets, particularly those induced by interferon-gamma, compared with that of skin psoriasis, which was mainly associated with activation of TNFα/L-17/IL-22-induced keratinocyte response genes. We also detected differences in expression of gene-sets involving negative regulation, epigenetic regulation, epidermal differentiation, and dendritic cell or Th1/Th17/Th22-related T-cell processes.

Efficacy and safety of Tripterygium wilfordii hook F versus acitretin in moderate to severe psoriasis vulgaris: a randomized clinical trial

Background:

Few clinical trials have evaluated the efficacy and safety of Tripterygium wilfordii Hook F (TwHF) compared with acitretin in psoriasis. We aimed to compare the efficacy and safety of TwHF compared with acitretin in the treatment of moderate to severe psoriasis vulgaris.

Methods:

Adults with Psoriasis Area Severity Index (PASI) score ≥ 10 and psoriasis-affected body surface area ≥ 10% were randomized into a TwHF (20 mg, 3 times a day) or acitretin group (30 mg, once a day). The treatment course lasted for 8 weeks. Patients were assessed at baseline and at 2, 4, and 8 weeks. Laboratory tests were performed at baseline, week 4, and week 8. The data were analyzed using paired samples t-test or analysis of variance (ANOVA).

Results:

A total of 115 patients was enrolled (58 TwHF; 57 acitretin). The median PASI score improved in the TwHF group by 50.4% and in the acitretin group by 42.7%. There was no significant difference in median PASI improvement between two groups at 2, 4, and 8 weeks. There was also no significant difference in PASI 25, PASI 50, PASI 75, and PASI 90 response between the two groups at 2, 4, and 8 weeks. There was a significant increase in the level of aspartate transaminase and triglycerides in the TwHF group (P = 0.026 and P = 0.011, respectively). In the acitretin group, there was a significant increase in the level of alanine transaminase, cholesterol, and high-density lipoprotein (P = 0.030, P < 0.01, and P < 0.01, respectively).

Conclusions:

There was no significant difference in treatment efficacy between the TwHF and acitretin groups within 8 weeks, but there were fewer treatment-related adverse events in the TwHF group.

Galectin-3 in autoimmunity and autoimmune diseases

Galectin-3 (gal-3) is a β-galactoside-binding lectin, which regulates cell-cell and extracellular interactions during self/non-self-antigen recognition and cellular activation, proliferation, differentiation, migration and apoptosis. It plays a significant role in cellular and tissue pathophysiology by organizing niches that drive inflammation and immune responses. Gal-3 has some therapeutic potential in several diseases, including chronic inflammatory disorders, cancer and autoimmune diseases. Gal-3 exerts a broad spectrum of functions which differs according to its intra- or extracellular localization. Recombinant gal-3 strategy has been used to identify potential mode of action of gal-3; however, exogenous gal-3 may not reproduce the functions of the endogenous gal-3. Notably, gal-3 induces monocyte-macrophage differentiation, interferes with dendritic cell fate decision, regulates apoptosis on T lymphocytes and inhibits B-lymphocyte differentiation into immunoglobulin secreting plasma cells. Considering the influence of these cell populations in the pathogenesis of several autoimmune diseases, gal-3 seems to play a role in development of autoimmunity. Gal-3 has been suggested as a potential therapeutic agent in patients affected with some autoimmune disorders. However, the precise role of gal-3 in driving the inflammatory process in autoimmune or immune-mediated disorders remains elusive. Here, we reviewed the involvement of gal-3 in cellular and tissue events during autoimmune and immune-mediated inflammatory diseases.

Laser capture microdissection followed by next-generation sequencing identifies disease-related microRNAs in psoriatic skin that reflect systemic microRNA changes in psoriasis

Psoriasis is a systemic disease with cutaneous manifestations. MicroRNAs (miRNAs) are small non-coding RNA molecules that are differentially expressed in psoriatic skin; however, only few cell- and region-specific miRNAs have been identified in psoriatic lesions. We used laser capture microdissection (LCM) and next-generation sequencing (NGS) to study the specific miRNA expression profiles in the epidermis (Epi) and dermal inflammatory infiltrates (RD) of psoriatic skin (N = 6). We identified 24 deregulated miRNAs in the Epi and 37 deregulated miRNAs in the RD of psoriatic plaque compared with normal psoriatic skin (FCH > 2, FDR < 0.05). Interestingly, 9 of the 37 miRNAs in RD, including miR-193b and miR-223, were recently described as deregulated in circulating peripheral blood mononuclear cells (PBMCs) from patients with psoriasis. Using flow cytometry and qRT-PCR, we found that miR-193b and miR-223 were expressed in Th17 cells. In conclusion, we demonstrate that LCM combined with NGS provides a robust approach to explore the global miRNA expression in the epidermal and dermal compartments of psoriatic skin. Furthermore, our results indicate that the altered local miRNA changes seen in the RD are reflected in the circulating immune cells, suggesting that miRNAs may contribute to the pathogenesis of psoriasis.

Connexins: sensors of epidermal integrity that are therapeutic targets

Gap junction proteins (connexins) are differentially expressed throughout the multiple layers of the epidermis. A variety of skin conditions arise with aberrant connexin expression or function and suggest that maintaining the epidermal gap junction network has many important roles in preserving epidermal integrity and homeostasis. Mutations in a number of connexins lead to epidermal dysplasias giving rise to a range of dermatological disorders of differing severity. 'Gain of function' mutations reveal connexin-mediated roles in calcium signalling within the epidermis. Connexins are involved in epidermal innate immunity, inflammation control and in wound repair. The therapeutic potential of targeting connexins to improve wound healing responses is now clear. This review discusses the role of connexins in epidermal integrity, and examines the emerging evidence that connexins act as epidermal sensors to a variety of mechanical, temperature, pathogen-induced and chemical stimuli. Connexins thus act as an integral component of the skin's protective barrier.