Psoriasis: from pathogenesis to novel therapeutic approaches

miR-181a/b-5p negatively regulates keratinocytes proliferation by targeting MELK

Accumulating evidence indicates that microRNAs (miRNAs) have a vital effect on the pathogenesis of psoriasis. This study is conducted to investigate the potential involvement of miR-181a-5p and miR-181b-5p in the proliferation of HaCaT keratinocytes. Cell viability and proliferation were evaluated respectively in this study using the CCK-8 and the 5-ethynyl-2'-deoxyuridine (EdU) assays. The expression of Maternal Embryonic Leucine Zipper Kinase (MELK) and Keratin 16 (KRT16) mRNA and protein in tissues and cells was assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The Luciferase reporter system analyzes the connection between miR-181a-5p/miR-181b-5p and MELK. The results showed that miR-181a/b-5p expression was downregulated in the psoriasis lesions and negatively regulated the proliferation of keratinocytes. MELK was directly targeted by miR-181a-5p/miR-181b-5p. In addition, HaCaT keratinocytes proliferation was inhibited by knockdown of MELK while promoted dramatically by MELK overexpression. Notably, miR-181a/b-5p mimics could attenuate the effects of MELK in keratinocytes. In conclusion, our research findings suggested miR-181a-5p and miR-181b-5p negatively regulate keratinocyte proliferation by targeting MELK, providing potential diagnostic biomarkers and therapeutic targets for psoriasis.

Psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors

PD-1 (programmed Death-1) immune checkpoint inhibitors have provided significant benefits to tumor patients. However, a considerable proportion of the patients develop immune-related adverse events (irAEs), of which cutaneous irAEs (cirAEs, e.g., psoriasis) occur relatively early. This review provides an overview of the current progress in psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. It not only describes the relevant influencing factors but also theoretically analyzes the immunological mechanisms that lead to the onset or exacerbation of psoriasis. Finally, the authors present guidelines for the treatment of psoriasis de novo or exacerbation by PD-1 checkpoint inhibitors. The review is intended to assist dermatologists in the early recognition and effective individualized management of such cirAE, which is helpful to continue or adjust the tumor-targeted immunotherapy on the basis of ensuring the quality of life of tumor patients.

Label-free electrochemical immunosensor as a reliable point-of-care device for the detection of Interleukin-6 in serum samples from patients with psoriasis

Interleukin-6 (IL-6) plays a crucial role in autoimmunity and chronic inflammation. This study aims to develop a low-cost, simple-to-manufacture, and user-friendly label-free electrochemical point-of-care device for the rapid detection of IL-6 in patients with psoriasis. Precisely, a sandwich-based format immunosensor was developed using two primary antibodies (mAb-IL6 clone-5 and clone-7) and screen-printed electrodes modified with an inexpensive recycling electrochemical enhancing material, called biochar. mAb-IL6 clone-5 was used as a covalently immobilized capture bioreceptor on modified electrodes, and mAb-IL6 clone-7 was used to recognize the immunocomplex (Anti-IL6 clone-5 and IL-6) and form the sandwich. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to conduct electrochemical characterization of the layer-by-layer assembly of the immunosensor, while square wave voltammetry (SWV) was used to perform the sensing. The developed immunosensor demonstrated robust analytical performance in buffer solution, with a wide linear range (LR) by varying from 2 to 250 pg/mL, a good limit of detection (LOD) of 0.78 pg/mL and reproducibility (RSD<7%). In addition, a spectrophotometric ELISA kit was employed to validate the results obtained with the label-free device by analyzing twenty-five serum samples from control and patients affected by psoriasis. A strong correlation in terms of pg/mL concentration of IL-6 was found comparing the two methods, with the advantage for our label-free biosensor of an ease use and a quicker detection time. Based on IL-6 levels, the proposed immunosensor is a dependable, non-invasive screening device capable of predicting disease onset, progression, and treatment efficacy.

TGF-β1 signaling and Smad7 control T-cell responses in health and immune-mediated disorders

Transforming growth factor (TGF)-β1, a member of the TGF-β superfamily, is produced by many immune and nonimmune cells and has pleiotropic effects on both innate and adaptive immunity, especially in the control of T-cell differentiation and function. Consistently, loss of TGF-β1 function is associated with exacerbated T-cell-dependent inflammatory responses that culminate in pathological processes in allergic and immune-mediated diseases. In this review, we highlight the roles of TGF-β1 in immunity, focusing mainly on its ability to promote differentiation of regulatory T cells, T helper (Th)-17, and Th9 cells, thus contributing to amplifying or restricting T-cell responses in health and human diseases (e.g., inflammatory bowel diseases, type 1 diabetes, asthma, and MS). In addition, we discuss the involvement of Smad7, an inhibitor of TGF-β1 signaling, in immune-mediated disorders (e.g., psoriasis, rheumatoid arthritis, MS, and inflammatory bowel diseases), as well as the discordant results of clinical trials with mongersen, an oral pharmaceutical compound containing a Smad7 antisense oligonucleotide, in patients with Crohn's disease. Further work is needed to ascertain the reasons for such a discrepancy as well as to identify better candidates for treatment with Smad7 inhibitors.

Psoriasis and Vitamin D: A Systematic Review and Meta-Analysis

Psoriasis is a chronic immune-dysregulated inflammatory disease and hypovitaminosis D is considered a risk factor. We conducted an online database search to review and meta-analyze the relationship between vitamin D, other bone metabolism parameters, and psoriasis. The efficacy of oral vitamin D supplementation in improving Psoriasis Area and Severity Index (PASI) was also evaluated. Non-original articles, case reports, and animal studies were excluded. Bias risk was assessed according to the Cochrane Collaboration's tool and the Newcastle-Ottawa scale in randomized controlled trials (RCTs) and case-control studies, respectively. Unstandardized mean differences were used for data synthesis. Twenty-three studies reported serum 25 hydroxyvitamin D (25(OH)D) levels in 1876 psoriasis patients and 7532 controls. Psoriasis patients had significantly lower 25(OH)D levels than controls (21.0 ± 8.3 vs. 27.3 ± 9.8, p < 0.00001). Conversely, 450 psoriasis patients had lower levels of parathormone than 417 controls (38.7 ± 12.8 vs. 43.7 ± 16.5, p = 0.015). Four RCTs examined the effect of oral vitamin D supplementation on psoriasis for 173 patients and 160 patients were treated with placebo. No significant differences were found in PASI after 3, 6, and 12 months of supplementation. It is shown that 25(OH)D serum levels are significantly lower in psoriasis, but, although the granularity of RCT methodology may have influenced the pooled analysis, vitamin D supplementation did not seem to improve clinical manifestations.

Comparative Analysis of the Therapeutic Effects of Fresh and Cryopreserved Human Umbilical Cord Derived Mesenchymal Stem Cells in the Treatment of Psoriasis

Psoriasis, an inflammatory autoimmune skin disease, is characterized by scaly white or erythematous plaques, which severely influence patients' quality of life and social activities. Mesenchymal stem cells derived from the human umbilical cord (UCMSCs) represent a promising therapeutic approach for psoriasis because of its unique superiority in ethical agreeableness, abundant source, high proliferation capacity, and immunosuppression. Although cryopreservation provided multiple benefits to the cell therapy, it also greatly compromised clinical benefits of MSCs due to impaired cell functions. The current study aims to evaluate the therapeutic efficacy of cryopreserved UCMSCs in a mouse model of psoriasis as well as in patients with psoriasis. Our results showed that cryopreserved and fresh UCMSCs have comparable effects on the suppression of psoriasis-like symptoms such as thickening, erythema, and scaling, and serum IL-17 A secretion in mice model of psoriasis. Moreover, psoriatic patients injected with cryopreserved UCMSCs had a significant improvement in the Psoriasis Area and Severity Index (PASI), Physician Global Assessment (PGA), and Patient Global Assessments (PtGAs) scores compared to baseline values. Mechanically, cryopreserved UCMSCs markedly inhibit the proliferation of PHA-activated PBMCs, type 1 T helper (Th1) and type 17 T helper (Th17) cell differentiation and secretion of inflammatory cytokines including IFN-γ, TNF-a and IL-17 A in PBMCs stimulated by anti-CD3/CD28 beads. Taken together, these data indicated that cryopreserved UCMSCs exhibited great beneficial effect on psoriasis. Thus, cryopreserved UCMSCs can be systemically administered as ''off-the-shelf'' cell product for psoriasis therapy. Trial Registration ChiCTR1800019509. Registered on November 15, 2018-Retrospectively registered, http://www.chictr.org.cn/ .

The elucidation of structure-activity and structure-permeation relationships for the cutaneous delivery of phytosterols to attenuate psoriasiform inflammation

Phytosterols have been reported to exert anti-inflammatory activity. This study aimed to investigate the capacity of campesterol, β-sitosterol, and stigmasterol on the mitigation of psoriasiform inflammation. We also tried to establish structure-activity and structure-permeation relationships for these plant sterols. To support this study, we first approached the in silico data of the physicochemical properties and the molecular docking of phytosterols with stratum corneum (SC) lipids. The anti-inflammatory activity of the phytosterols was explored in the activated keratinocytes and macrophages. Using the activated keratinocyte model, a significant inhibition of IL-6 and CXCL8 overexpression by phytosterols was detected. A comparable inhibition level was found for the three phytosterols tested. The macrophage-based study showed that the anti-IL-6 and anti-CXCL8 activities of campesterol were greater than those of the other compounds, which indicated that a phytosterol structure without a double bond on C₂₂ and with methyl moiety on C₂₄ was more effective. The conditioned medium of phytosterol-treated macrophages decreased STAT3 phosphorylation in the keratinocytes, suggesting the inhibition of keratinocyte hyperproliferation. β-sitosterol was the penetrant with the highest pig skin absorption (0.33 nmol/mg), followed by campesterol (0.21 nmol/mg) and stigmasterol (0.16 nmol/mg). The therapeutic index (TI) is a parameter measured by multiplying the cytokine/chemokine suppression percentage with skin absorption for anticipating the anti-inflammatory activity after topical delivery. β-sitosterol is a potential candidate for treating psoriatic inflammation due to having the greatest TI value. In this study, β-sitosterol attenuated epidermal hyperplasia and immune cell infiltration in the psoriasis-like mouse model. The psoriasiform epidermis thickness could be reduced from 92.4 to 63.8 μm by the topical use of β-sitosterol, with a downregulation of IL-6, TNF-α, and CXCL1. The skin tolerance study manifested that the reference drug betamethasone but not β-sitosterol could generate barrier dysfunction. β-sitosterol possessed anti-inflammatory activity and facile skin transport, showing the potential for development as an anti-psoriatic agent.

Circ_0082476 targets miR-138-5p to promote proliferation, invasion, migration and inflammation in IL-22-treated human keratinocytes by upregulating BRD4

BACKGROUND

Circular RNAs (circRNAs) are implicated in the disease progression via acting as sponges of microRNAs (miRNAs) to regulate gene expression. The purpose of this study was to analyze the involvement of circ_0082476 in Interleukin-22 (IL-22)-induced psoriasis.

METHODS

Expression detection for circ_0082476, microRNA-424-5p (miR-138-5p) or toll-like receptor (BRD4) was completed using reverse transcription-quantitative polymerase chain reaction assay. Cell Counting Kit-8 assay and EdU assay were used for analysis of cell viability and proliferation, respectively. Cell invasion and migration abilities were assessed through transwell assay and wound healing assay. The protein expression was examined via western blot. Inflammatory reaction was determined via Enzyme-linked immunosorbent assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted for target binding research.

RESULTS

Circ_0082476 was significantly elevated in psoriasis patients and IL-22-treated keratinocytes (HaCaT). Knockdown of circ_0082476 reduced cell proliferation, invasion and migration in IL-22-treated HaCaT cells. Circ_0082476 induced sponge effect on miR-138-5p. Circ_0082476 regulated IL-22-induced cell injury through targeting miR-138-5p. BRD4 was confirmed as a target of miR-138-5p, and miR-138-5p relieved IL-22-induced cell dysfunction by the direct downregulation of BRD4. BRD4 was positively regulated by circ_0082476 via sponging miR-138-5p.

CONCLUSION

These findings disclosed that circ_0082476 facilitated the IL22-induced epidermis cell injury in psoriasis through the upregulation of BRD4 via binding to miR-138-5p.

Weighted Gene Co-Expression Network Analysis of Oxymatrine in Psoriasis Treatment

Purpose

Psoriasis is a common, chronic, inflammatory, recurrent, immune-mediated skin disease. Oxymatrine is effective for treating moderate and severe psoriasis. Here, transcriptional changes in skin lesions before and after oxymatrine treatment of patients with psoriasis were identified using full-length transcriptome analysis and then compared with those of normal skin tissues.

Patients and Methods

Co-expression modules were constructed by combining the psoriasis area and severity index (PASI) score with weighted gene co-expression network analysis to explore the action mechanism of oxymatrine in improving clinical PASI. The expression of selected genes was verified using immunohistochemistry, quantitative real-time PCR, and Western blotting.

Results

Kyoto Encyclopedia of Gene and Genome pathway analysis revealed that oxymatrine treatment reversed the abnormal pathways, with an improvement in lesions and a reduction in PASI scores. Gene Ontology (GO) analysis revealed that oxymatrine treatment led to altered GO terms being regulated with a decrease in the PASI score in patients. Therefore, oxymatrine treatment may improve the skin barrier, differentiation of keratinocytes, and alleviate abnormality of organelles such as desmosomes. Protein-protein interaction network interaction analysis revealed that the top five hub genes among many interrelated genes were CNFN, S100A8, SPRR2A, SPRR2D, and SPRR2E, associated with the epidermal differentiation complex (EDC). EDC regulates keratinocyte differentiation. This result indicates that oxymatrine treatment can restore keratinocyte differentiation by regulating the expression of EDC-related genes.

Conclusion

Oxymatrine can improve erythema, scales, and other clinical symptoms of patients with psoriasis by regulating EDC-related genes and multiple pathways, thereby promoting the repair of epithelial tissue and maintaining the dynamic balance of skin keratosis.

Sis-25, a meroditerpenoid derivative with a cyclobutane scaffold, inhibits activated T cell proliferation by targeting GSK3β in vitro and in vivo

A series of novel scopariusicide derivatives were designed and synthesized starting from the main diterpenoid from the aerial parts of Isodon scoparius. Sis-25 was the most effective compound among them. The potential mechanism(s) of its immunosuppressive activity in vitro, as well as its effects on delayed type hypersensitivity (DTH) reaction and imiquimod-induced dermatitis in vivo were investigated in this study. Sis-25 inhibited anti-CD3/anti-CD28 mAbs, PHA or alloantigen-induced T cell proliferation without obvious cytotoxicity. Sis-25 was a highly selective inhibitor of GSK3-β and inhibited the mTOR/p70S6K pathway but not the PI3K/Akt, p38 MAPK/ERK 1/2 and JAK3/STAT5 pathways. Furthermore, Sis-25 significantly inhibited IFN-γ, IL-6 and IL-17 expression but not IL-10 expression in activated T cells. Finally, Sis-25 treatment mitigated the DNFB-induced DTH reaction and ameliorated imiquimod-induced dermatitis. In summary, Sis-25 exerted significant immunosuppressive activity by targeting GSK3β in vitro and in vivo. Sis-25 may guide the design of new drugs for more effective and safer treatments of autoimmune diseases and provide new insight into developing utilizations of Isodon scoparius.

Vorinostat, a histone deacetylase inhibitor, as a potential novel treatment for psoriasis

BACKGROUND

Psoriasis is characterized by aberrant activation of several pro-inflammatory circuits as well as abnormal hyperproliferation and dysregulated apoptosis of keratinocytes (KCs). Most currently available therapeutic options primarily target psoriasis-associated immunological defects rather than epidermal abnormalities.

OBJECTIVE

To investigate the efficacy of the histone deacetylase (HDAC) inhibitor, Vorinostat, in targeting hyperproliferation and impaired apoptosis in psoriatic skin.

METHODS

Vorinostat effect was investigated in primary KCs cell cultures using cell cycle analysis by flow cytometry, apoptosis assays (Annexin V-FICH and caspase-3/7) and antibody arrays, qRT-PCR and immunohistochemistry. Vorinostat impact on clinical manifestations of psoriasis was investigated in a chimeric mouse model.

RESULTS

Vorinostat was found to inhibit KCs proliferation and to induce their differentiation and apoptosis. Using a chimeric mouse model, vorinostat was found to result in marked attenuation of a psoriasiform phenotype with a significant decrease in epidermal thickness and inhibition of epidermal proliferation.

CONCLUSIONS

Our results support the notion that vorinostat, a prototypic HDAC inhibitor, may be of potential use in the treatment of psoriasis and other hyperproliferative skin disorders.

The therapeutic effects of Bombyx mori sericin on rat skin psoriasis through modulated epidermal immunity and attenuated cell proliferation

Background and aim

Psoriasis is a skin disorder that leads to chronic inflammation and keratinocyte hyperproliferation. Sericin extracted from Bombyx mori cocoon has been demonstrated to possess anti-inflammatory and antiproliferative properties, which makes it a viable candidate for psoriasis treatment. This study aimed to investigate the therapeutic effect of sericin on skin psoriasis at the cellular level.

Experimental procedure

Imiquimod-induced skin psoriasis was established in Sprague-Dawley rats. The rats with psoriasis were divided into 6 groups (n = 5), namely, one nontreatment control group and five groups that received different treatments: sericin (2.5%, 5%, and 10%), 0.1% betamethasone, 3 μg/ml calcitriol. The treatments were administered twice daily for 7 days, followed by skin sample collection. Epidermal improvement and protein expression were evaluated using histopathological and label-free proteomic approaches and immunohistochemistry.

Results and conclusion

Compared with other concentrations, 10% sericin had the desired effect of improving skin psoriasis as shown by reduced epidermal thickness, similar to the effects of betamethasone and calcitriol treatments. Anti-inflammatory activity was shown by decreased C–C motif chemokine 20 (CCL20) expression posttreatment. Proteomic observation revealed that sericin reduced cytokine production by Th17 cells by interfering with the JAK-STAT signaling pathway. Sericin treatment also resulted in a modulated immune response via upregulation of Galectin-3 (Lgals3) and downregulation of Sphingosine-1-phosphate lyase1 (Sgpl1). Sericin improved epithelial cell proliferation by upregulating Nucleoside diphosphate kinase B (Nme2). Therefore, the therapeutic effect of sericin on psoriasis correlated with a reduced immune response and attenuated epidermal proliferation, making sericin a promising approach for skin psoriasis treatment.

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Sericin extracted from Bombyx mori cocoon ameliorates skin psoriasis.

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Sericin modulated immune response and epithelial cell proliferation in skin-psoriasis rat model.

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Sericin upregulated Lgals3 and downregulated Sgpl1 in immune system.

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Downregulated Nme2 of skin psoriasis by sericin treatment reduces epithelial cell proliferation.

MiR-193b-3p-ERBB4 axis regulates psoriasis pathogenesis via modulating cellular proliferation and inflammatory-mediator production of keratinocytes

Psoriasis is an auto-inflammatory skin disease characterized by abnormal activation of epidermal keratinocytes, aberrant neovascularization, and dysregulation of immune cells. MicroRNAs are small non-coding RNAs that mainly function in the post-transcriptional regulation of gene expression. Recently, accumulating evidence has demonstrated that expression of microRNAs is dysregulated in psoriasis patients and microRNAs play key roles in psoriasis pathogenesis. Downregulation of miR-193b-3p has been identified to be associated with psoriasis development. However, the precise functions and action mechanisms of miR-193b-3p in psoriasis pathogenesis remain unclear. In this study, we confirmed the downregulation of miR-193b-3p in psoriasis patients, psoriasis-like inflammatory cellular models, and an imiquimod (IMQ) -induced mouse model. A negative correlation was found between miR-193b-3p level and patient Psoriasis Area and Severity Index (PASI) score. Furthermore, miR-193b-3p suppressed proliferation, inflammatory-factor secretion, and the STAT3 and NF-κB signaling pathways in keratinocytes. Importantly, intradermal injection of agomiR-193b-3p blocked, whereas antagomiR-193b-3p augmented, the psoriasis-like inflammation in the IMQ-induced mouse model. Bioinformatics analysis and the dual-luciferase reporter assay showed that miR-193b-3p targets ERBB4 3' untranslated region (UTR). In addition, ERBB4 induced proliferation, inflammatory-factor production, and the STAT3 and NF-κB pathways in keratinocytes. Most importantly, forced expression of ERBB4 could attenuate the effects of miR-193b-3p in keratinocytes, indicating that miR-193b-3p inhibits keratinocyte activation by directly targeting ERBB4. In conclusion, our findings demonstrated that the miR-193b-3p-ERBB4 axis underlies the hyperproliferation and aberrant inflammatory-factor secretion of psoriatic keratinocytes, providing a novel, microRNA-related causal mechanism and a potential therapeutic target in psoriasis.

Roles of IL-25 in Type 2 Inflammation and Autoimmune Pathogenesis

Interleukin-17E (IL-25) is a member of the IL-17 cytokine family that includes IL-17A to IL-17F. IL-17 family cytokines play a key role in host defense responses and inflammatory diseases. Compared with other IL-17 cytokine family members, IL-25 has relatively low sequence similarity to IL-17A and exhibits a distinct function from other IL-17 cytokines. IL-25 binds to its receptor composed of IL-17 receptor A (IL-17RA) and IL-17 receptor B (IL-17RB) for signal transduction. IL-25 has been implicated as a type 2 cytokine and can induce the production of IL-4, IL-5 and IL-13, which in turn inhibits the differentiation of T helper (Th) 17. In addition to its anti-inflammatory properties, IL-25 also exhibits a pro-inflammatory effect in the pathogenesis of Th17-dominated diseases. Here, we review recent advances in the roles of IL-25 in the pathogenesis of inflammation and autoimmune diseases.

Photothermal treatment by PLGA-gold nanorod-isatin nanocomplexes under near-infrared irradiation for alleviating psoriasiform hyperproliferation

Psoriasis is a chronic autoimmune skin disorder that involves keratinocyte hyperproliferation and inflammatory cell recruitment. A strategy to mitigate psoriatic lesions is to induce keratinocyte apoptosis for proliferation suppression. Herein we designed a nanoformulation capable of treating psoriasis via hyperthermia-induced apoptosis in response to near-infrared (NIR) irradiation. To this end, gold nanorods (GNRs) and isatin, which is an anti-inflammatory agent for synergizing antipsoriatic activity, were loaded into a poly (lactic-co-glycolic acid) (PLGA) matrix to form the nanocomplexes. The physicochemical and photothermal properties of the nanocomplexes were determined in terms of size, surface charge, NIR-absorbing feature, isatin release, keratinocyte uptake, and cytotoxicity. The nanocomplexes showed a spherical shape with an average size of about 180 nm. The GNR-loaded nanoparticles can efficiently convert NIR light at 0.42 W/cm² into heat with an increased temperature of 10 °C. When combined with NIR exposure, the nanocomplexes were internalized into keratinocyte cytoplasm with an inhibition of keratinocyte viability to about 60%. Live/dead cell assay and flow cytometry confirmed that the nanocomplexes could serve as NIR-absorbers to specifically elicit keratinocyte apoptosis through caspase and poly ADP-ribose polymerase (PARP) pathways. The in vivo psoriasiform murine model indicated that the combined nanocomplexes and NIR inhibited epidermal hyperplasia and neutrophil infiltration. The overexpressed cytokines in the lesion could be recovered to normal baseline level after the photothermal management. The subcutaneous nanocomplexes remained in the skin for at least 5 days. The nanocomposites produced a negligible toxicity in the skin or liver of healthy mice. The photothermal nanosystems, as designed in this study, shed new light on the therapeutic approach against psoriasis.

Monovalent antibody-conjugated lipid-polymer nanohybrids for active targeting to desmoglein 3 of keratinocytes to attenuate psoriasiform inflammation

To improve the treatment of psoriasiform inflammation, we developed actively targeted nanocarriers loaded with the phosphodiesterase 4 inhibitor AN2728. Methods: Phospholipid-poly(lactic-co-glycolic acid) nanohybrids were prepared and conjugated with monovalent anti-desmoglein 3 antibody to bind keratinocytes. Results: The actively targeted nanohybrids were 229 nm in mean size with a nearly neutral surface charge. Flow cytometry and confocal microscopy showed a 9-fold increase in keratinocyte uptake of targeted nanohybrids relative to non-targeted nanoparticles. The nanoparticles localized mainly in lysosomes after internalization. AN2728-loaded antibody-conjugated nanocarriers inhibited cytokine/chemokine overexpression in activated keratinocytes without affecting cell viability. The targeted nanohybrids also suppressed neutrophil migration by reducing CXCL1 and CXCL2 release from keratinocytes. Following subcutaneous administration in mice, the nanohybrids distributed to the epidermis and hair follicles. In a psoriasis-like skin mouse model, the actively targeted nanoparticles were superior to free drug and non-targeted nanoparticles in mitigating skin inflammation. Intervention with the targeted nanosystem reduced the epidermal thickness of the psoriasiform lesion from 191 to 42 µm, decreased the Psoriasis Area Severity Index by 74%, restored barrier function, and returned chemokine levels to baseline. Conclusions: Our developed nanosystem was safe and demonstrated efficient targeting properties for the treatment of cutaneous inflammation.

An ex vivo skin model to probe modulation of local cutaneous arachidonic acid inflammation pathway

There is a need for inexpensive and reliable means to determine the modulation of cutaneous inflammation. The method outlined in this article draws together a number of scientific techniques and makes use of generally unwanted biological tissues as a means of determining skin inflammation ex vivo, and focuses on probing aspects of the arachidonic acid inflammation pathway. Freshly excised skin contains elevated levels of short-lived inducible cyclooxygenase-2 (COX-2) and, under viable conditions, COX-2 and its eicosanoid products will continue to be produced until tissue necrosis, providing a window of time in which relative levels can be probed to determine exacerbation due to an upregulating factor or downregulation due the presence of an agent exerting anti-inflammatory activity. Ex vivo porcine skin, mounted in Franz diffusion cells, is dosed topically with the xenobiotic challenge and then techniques such as Western blotting and immunohistochemistry can then be used to probe relative COX-2 levels on a semi-quantitative or qualitative level. Enzyme-linked immunosorbent assay or LCMS can be used to determine relative prostaglandin E-2 (PGE-2) levels. Thus far, the technique has been used to examine the effects of topically applied anti-inflammatories (betamethasone, ibuprofen, ketoprofen and methotrexate), natural products (fish oil, Devil’s claw extract and pomegranate rind extract) and drug delivery vehicle (polyNIPAM nanogels). Topically applied xenobiotics that modulate factors such as COX-2 and PGE-2 must penetrate the intact skin, and this provides direct evidence of overcoming the "barrier function" of the stratum corneum in order to target the viable epidermis in sufficient levels to be able to elicit such effects. This system has particular potential as a pre-clinical screening tool for those working on the development of topical delivery systems, and has the additional advantage of being in line with 3 Rs philosophy.

Evaluating the effect of rice (Oryza sativa L.: SRNC05053-6-2) crude extract on psoriasis using in vitro and in vivo models

Psoriasis is mainly caused because of inappropriate immune responses in the epidermis. Rice (Oryza sativa L.: SRNC05053-6-2) consists of anthocyanin, which exhibits strong antioxidative and anti-inflammatory properties. This study aimed to evaluate the role of this black-coloured rice crude extract in alleviating the symptoms of psoriasis using human psoriatic artificial skin and an imiquimod-induced rat psoriasis model. Psoriasis-related genes, cytokines and chemokines were examined; in addition, the antioxidative and anti-inflammatory properties and the immunohistopathological features of this condition were studied. The results showed that the rice extract reduced the severity of psoriasis by (1) decreasing the epidermal thickness, acanthosis, hyperkeratosis, epidermal inflammation and degree of apoptosis induction via caspase-3, (2) increasing the expression levels of anti-inflammatory cytokines (IL-10 and TGF-β), (3) reducing the levels of pro-inflammatory cytokines (IL-6, IL-8, IL-20, IL-22 and TNF-α), chemokines (CCL-20) and anti-microbial peptides (psoriasin and β-defensin), (4) enhancing the antioxidative property (Nrf-2), (5) downregulating the levels of psoriasis-associated genes (psoriasin, β-defensin, koebnerisin 15L and koebnerisin 15S) and (6) upregulating the levels of psoriasis-improving genes (caspase-14, involucrin and filaggrin). Thus, the extract appears to exert therapeutic effects on psoriasis through its antioxidative and immunomodulatory properties.

miR-203 promotes HaCaT cell overproliferation through targeting LXR-α and PPAR-γ

Psoriasis is an immune-mediated chronic inflammatory skin disease. Keratinocyte hyperproliferation has been regarded as a significant event in psoriasis pathogenesis. Considering the vital role of miRNA-mediated mRNA repression in psoriasis pathogenesis, in the present study, we attempted to investigate the mechanism of keratinocyte overproliferation from the point of miRNA-mRNA regulation. Both online microarray expression profiles and experimental results indicated that the expression of LXR-α and PPAR-γ was downregulated in psoriasis lesion skin. LXR-α or PPAR-γ overexpression alone was sufficient to inhibit keratinocyte proliferation, decrease KRT5 and KRT14 protein levels and increase KRT1 and KRT10 protein levels. miR-203 negatively regulated LXR-α and PPAR-γ expression through direct targeting. miR-203 inhibition exerted the opposite effects to LXR-α or PPAR-γ overexpression on HaCaT cells. More importantly, LXR-α or PPAR-γ overexpression could markedly remarkably attenuate the effects of miR-203 overexpression in keratinocytes, indicating that miR-203 promotes keratinocyte proliferation by targeting LXR-α and PPAR-γ. In conclusion, the miR-203-LXR-α/PPAR-γ axis modulates the proliferation of keratinocytes and might be a novel target for psoriasis treatment, which needs further in vivo investigation.

Facile skin targeting of a thalidomide analog containing benzyl chloride moiety alleviates experimental psoriasis via the suppression of MAPK/NF-κB/AP-1 phosphorylation in keratinocytes

BACKGROUND

Thalidomide can be a TNF-α inhibitor for treating skin inflammation. This drug exhibits a strong toxicity that limits its application.

OBJECTIVE

We synthesized a thalidomide analog containing the benzyl chloride group (2-[1-(3-chlorobenzyl)-2,6-dioxopiperidin-3-yl]isoindoline-1,3-dione, CDI) to examine anti-inflammatory activity against psoriasis.

METHODS

The evaluation was conducted by the experimental platforms of in vitro TNF-α- or imiquimod (IMQ)-stimulated HaCaT cells and in vivo IMQ-induced psoriasiform plaque.

RESULTS

Using the in vitro keratinocyte model, we demonstrated a greater inhibition of IL-1β, IL-6, and IL-24 by CDI than by thalidomide. No significant cytotoxicity was observed at 100 μM. CDI delivered facilely into the skin with a cutaneous targeting ability 228-fold greater than thalidomide. CDI caused a negligible irritation on healthy mouse skin. We showed that topically applied CDI reduced IMQ-induced red scaly lesions, hyperplasia, microabscesses, and cytokine expression in the mouse model. The skin-barrier function measured by transepidermal water loss (TEWL) could be partially recovered from 50.6-36.3 g/m²/h by CDI. The mechanistic study showed that CDI suppressed cytokine production by inhibiting the phosphorylation of NF-κB and AP-1 via MAPK pathways.

CONCLUSION

CDI would be beneficial for the development of a therapeutic agent against psoriasis.

miR124-3p/FGFR2 axis inhibits human keratinocyte proliferation and migration and improve the inflammatory microenvironment in psoriasis

Keratinocyte hyperproliferation has been regarded as a central event in psoriasis pathogenesis. Investigating the mechanisms of keratinocyte hyperproliferation might provide novel strategies for psoriasis treatment. we demonstrated that fibroblast growth factor receptor 2 (FGFR2) expression was abnormally upregulated within psoriatic lesion tissues and HaCaT cells under rIL-22 stimulation. FGFR2 silence within HaCaT cells under rIL-22 stimulation significantly inhibited the capacity of cells to proliferate and to migrate, reduced IL-17A and TNFα mRNA expression, and decreased the protein levels of FGFR2, keratin 6, keratin 16, MMP1, MMP9, p-PI3K, p-AKT and p-ERK. In contrast to FGFR2, the expression of miR-124-3p showed to be remarkably downregulated within psoriasis lesion tissue samples and rIL-22-stimulated HaCaT cells. miR-124-3p inhibited the expression of FGFR2 via direct binding to its 3'UTR. Within HaCaT cells under rIL-22 stimulation, the overexpression of miR-124-3p also suppressed the capacity of cells to proliferate and to migrate, reduced IL-17A and TNFα mRNA expression, and decreased the protein levels of FGFR2, keratin 6, keratin 16, MMP1, MMP9 and p-PI3K, p-AKT and p-ERK. More importantly, when co-transfected to HaCaT cells, FGFR2-overexpressing vector significantly attenuated the effects of miR-124-3p mimics on HaCaT cells. In conclusion, we demonstrated an miR124-3p/FGFR2 axis that might inhibit human keratinocyte proliferation, migration, and improve the inflammatory microenvironment in psoriasis. miR124-3p/FGFR2 axis could be an underlying target for psoriasis therapy, which requires further in vivo and clinical investigation.

(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.

Bioactivity-Guided Isolation and Identification of New and Immunosuppressive Monoterpenoid Indole Alkaloids from Rauvolfia yunnanensis Tsiang

Three new 11-hydroxyburnamine (1) and rauvoyunnanines A-B (2-3), and fourteen known (4-17) monoterpenoid indole alkaloids were isolated from the total alkaloids extract of Rauvolfia yunnanensis, which exhibited promising immunosuppressive activity on T cell proliferation in preliminary screening. Their structures were determined by analysis of high-resolution electrospray ionization mass (HRESIMS), ultraviolet (UV) and nuclear magnetic resonance (NMR) data, and by comparison with the literature. All the alkaloids were evaluated for inhibitory activity on T cell proliferation. Among them, one new compound (1) and reserpine (6) exhibited moderate immunosuppressive activity, with IC50 values of 5.9 μM and 5.0 μM, respectively.

Association between psoriasis and celiac disease: A systematic review and meta-analysis

BACKGROUND

Multiple studies have examined the association between psoriasis and celiac disease (CD). However, these studies have shown conflicting results.

OBJECTIVE

To analyze the association between psoriasis and CD.

METHODS

We conducted a systematic review of the case-control, cross-sectional, and cohort studies examining the association between psoriasis and CD in the PubMed, Scopus, and Cochrane databases. The adjusted effect sizes or crude data were extracted for quantitative analysis.

RESULTS

Of 754 citations initially identified, 18 studies were included. Random effects meta-analysis found significant odds ratios of 2.16 (95% confidence interval, 1.74-2.69; 9 studies) for CD in patients with psoriasis and 1.8 (95% confidence interval, 1.36-2.38; 8 studies) for psoriasis in patients with CD. We also found a significantly increased risk of new-onset psoriasis in CD (hazard ratio, 1.75; 95% confidence interval, 1.58-1.93). Subgroup analyses according to disease severity and geographic region could not be performed due to limited data.

CONCLUSION

This 2-way meta-analysis found a significant association between psoriasis and CD. Clinicians should be aware of this association. Patients with psoriasis with bowel complaints might benefit from screening for CD through questionnaires or interviews with subsequent gastroenterology consultation.

Cutaneous delivery of [1-(4-chloro-3-nitrobenzenesulfonyl)-1H-indol-3-yl]-methanol, an indole-3-carbinol derivative, mitigates psoriasiform lesion by blocking MAPK/NF-κB/AP-1 activation

[1-(4-chloro-3-nitrobenzenesulfonyl)-1H-indol-3-yl]-methanol (CIM) has been used as a bioactive agent for inhibiting tumor growth and angiogenesis via mitogen-activated protein kinase (MAPK) and NF-κB blocking. The present work was undertaken to investigate the potential of CIM against psoriasis using imiquimod (IMQ)-stimulated psoriasis-like mouse and in vitro HaCaT keratinocytes as the models. We demonstrated that topical CIM treatment reduced IMQ-activated scaling, erythema, and barrier dysfunction. This compound also restrained the recruitment of neutrophils. The cytokines, including TNF-α, IL-1β, IL-6, and IL-17 in psoriasiform skin, can be attenuated to normal baseline by CIM. Topically applied CIM can be easily delivered into skin based on the affinity with stratum corneum (SC) ceramides. IMQ intervention increased the permeability by 3-fold as compared to healthy skin. CIM ameliorated psoriatic lesion without incurring overt signs of irritation. Both TNF-α and IMQ were employed as the stimulators to activate HaCaT for reciprocal elucidation of the mechanism of action. CIM inhibited the overexpression of IL-1β, IL-6, and IL-24 in HaCaT. CIM exerted anti-inflammatory activity by suppressing the phosphorylation of NF-κB and activator protein-1 (AP-1) through MAPK pathways. Our results indicate that CIM has potential as the antipsoriatic molecule. The detailed signaling pathways still need further investigation.

Apoptotic or Antiproliferative Activity of Natural Products against Keratinocytes for the Treatment of Psoriasis

Natural products or herbs can be used as an effective therapy for treating psoriasis, an autoimmune skin disease that involves keratinocyte overproliferation. It has been demonstrated that phytomedicine, which is used for psoriasis patients, provides some advantages, including natural sources, a lower risk of adverse effects, and the avoidance of dissatisfaction with conventional therapy. The herbal products’ structural diversity and multiple mechanisms of action have enabled the synergistic activity to mitigate psoriasis. In recent years, the concept of using natural products as antiproliferative agents in psoriasis treatment has attracted increasing attention in basic and clinical investigations. This review highlights the development of an apoptotic or antiproliferatic strategy for natural-product management in the treatment of psoriasis. We systematically introduce the concepts and molecular mechanisms of keratinocyte-proliferation inhibition by crude extracts or natural compounds that were isolated from natural resources, especially plants. Most of these studies focus on evaluation through an in vitro keratinocyte model and an in vivo psoriasis-like animal model. Topical delivery is the major route for the in vivo or clinical administration of these natural products. The potential use of antiproliferative phytomedicine on hyperproliferative keratinocytes suggests a way forward for generating advances in the field of psoriasis therapy.

DLX3-Dependent STAT3 Signaling in Keratinocytes Regulates Skin Immune Homeostasis

Epidermal-specific deletion of the homeobox transcription regulator DLX3 disrupts keratinocyte differentiation and results in an IL-17-linked psoriasis-like skin inflammation. To identify the epidermal initiating signals produced by DLX3-null keratinocytes, we performed acute deletion of DLX3 in adult epidermis using a tamoxifen-inducible Krt14-cre/ERT system. K14CreERT;DLX3fl/fl skin exhibited dysregulated expression of differentiation-associated genes, upregulation of proinflammatory cytokines, and accumulation of Langerhans cells and macrophages within 3 days of tamoxifen-induced DLX3 ablation. We also observed increased accumulation of IL-17A-secreting Vγ4 γδ T cells and heightened levels of IL-17 and IL-36 family of cytokines starting 1 week after DLX3 deletion. Interestingly, transcriptome profiling of K14CreERT;DLX3fl/fl epidermis at 3 days identified activated STAT3 as a transcriptional regulator and revealed differential expression of STAT3 signaling-related genes. Furthermore, activation of STAT3 was strongly increased in K14CreERT;DLX3fl/fl skin, and topical treatment with an inhibitor of STAT3 activation attenuated the immune phenotype. RNA-seq analysis of vehicle and STAT3 inhibitor treated K14CreERT;DLX3fl/fl skin identified differentially expressed genes associated with inhibition of leukocyte infiltration. Collectively, our results show that DLX3 is a critical regulator of STAT3 signaling network that maintains skin homeostasis.

Anti-PD1/PDL1 induced psoriasis

BACKGROUND

Immune checkpoint inhibitors are novel agents approved for the treatment of late-stage malignancies. Despite its important clinical benefits, checkpoint inhibition is associated with a unique spectrum of side effects known as immune-related adverse events. Skin toxicities are the most frequent immune-related adverse events during anti-PD1 blockade therapies. Among them, rare cases of psoriasis exacerbation have been reported.

METHODS

We present the clinical characteristics of exacerbated psoriasis in 5 patients under anti-PD1/PDL1 therapy.

RESULTS

A total of 5 patients were overall included (4 males, 1 female mean age 65.8 years). Among them, 3 were diagnosed with nonsmall cell lung cancer, 1 with papillary urothelial carcinoma, and 1 with squamous cell carcinoma of the tonsil. Of all, 3 patients were treated with anti-PD1 (1 with pembrolizumab, 2 with nivolumab), whereas the remaining 2 with anti-PDL1 (durvalumab). Only 1 out of 5 patients had active psoriatic lesions at the time of treatment initiation, 2 shared a past history of psoriasis, and 1 reported a strong related family history (3/5 siblings). Four out of 5 patients experienced guttate lesions, though the most severe exacerbation was noted in the durvalumab group. Four out of 5 patients managed to continue treatment after close dermatologic monitoring, whereas 1 patient under durvalumab was forced to treatment delays owing to the severity of the skin reactions. Skin rashes appeared in all patients after the fourth cycle of immunotherapy.

CONCLUSIONS

Both anti-PD1 and anti-PDL1 therapies can lead to psoriasis exacerbation although more severe flares were noted in patients treated with durvalumab. Not only personal but also related family history of psoriasis are significant risk factors and need to be outlined before treatment initiation. If such related history exists, strict skin surveillance can lead to the early diagnosis and treatment of any psoriatic exacerbations that could otherwise severely affect quality of life or even compromise therapeutic protocols and final prognosis.

Safety and pharmacodynamics of dalazatide, a Kv1.3 channel inhibitor, in the treatment of plaque psoriasis: A randomized phase 1b trial

BACKGROUND

Dalazatide is a specific inhibitor of the Kv1.3 potassium channel. The expression and function of Kv1.3 channels are required for the function of chronically activated memory T cells, which have been shown to be key mediators of autoimmune diseases, including psoriasis.

OBJECTIVE

The primary objective was to evaluate the safety of repeat doses of dalazatide in adult patients with mild-to-moderate plaque psoriasis. Secondary objectives were to evaluate clinical proof of concept and the effects of dalazatide on mediators of inflammation in the blood and on chronically activated memory T cell populations.

METHODS

Patients (n = 24) were randomized 5:5:2 to receive dalazatide at 30 mcg/dose, 60 mcg/dose, or placebo twice weekly by subcutaneous injection (9 doses total). Safety was assessed on the basis of physical and neurological examination and laboratory testing. Clinical assessments included body-surface area affected, Psoriasis Area and Severity Index (PASI), and investigator and patient questionnaires.

RESULTS

The most common adverse events were temporary mild (Grade 1) hypoesthesia (n = 20; 75% placebo, 85% dalazatide) and paresthesia (n = 15; 25% placebo, 70% dalazatide) involving the hands, feet, or perioral area. Nine of 10 patients in the 60 mcg/dose group had a reduction in their PASI score between baseline and Day 32, and the mean reduction in PASI score was significant in this group (P < 0.01). Dalazatide treatment reduced the plasma levels of multiple inflammation markers and reduced the expression of T cell activation markers on peripheral blood memory T cells.

LIMITATIONS

The study was small and drug treatment was for a short duration (4 weeks).

CONCLUSION

This study indicates that dalazatide is generally well tolerated and can improve psoriatic skin lesions by modulating T cell surface and activation marker expression and inhibiting mediators of inflammation in the blood. Larger studies of longer duration are warranted.

Monoterpenoid Indole Alkaloids from Kopsia officinalis and the Immunosuppressive Activity of Rhazinilam

Six new monoterpenoid indole alkaloids, kopsinidines C-E (1-3), 11,12-methylenedioxychanofruticosinic acid (4), 12-methoxychanofruticosinic acid (5), and N(4)-methylkopsininate (7), as well as chanofruticosinic acid (6, as a natural product) and 23 known alkaloids, were obtained from the twigs and leaves of Kopsia officinalis. Their structures were characterized by physical data analysis. All isolated compounds were evaluated for their immunosuppressive activity on human T cell proliferation. Rhazinilam (29) significantly inhibited human T cell proliferation activated by anti-CD3/anti-CD28 antibodies (IC₅₀ = 1.0 μM) and alloantigen stimulation (IC₅₀ = 1.1 μM) without obvious cytotoxicity for naïve human T cells and peripheral blood mononuclear cells (0-320 μM). Although it did not affect T cell activation, it induced T cell cycle arrest in the G₂/M phase and inhibited proinflammatory cytokine production in activated T cells.

Suppressive effect of β,β-dimethylacryloyl alkannin on activated dendritic cells in psoriasis by the TLR7/8 pathway

β,β-dimethylacryloyl alkannin (DMA) is a key component of Lithospermum and possesses good efficacy for treating psoriasis. DMA inhibits activated dendritic cells (DCs), but the mechanism is unknown. Therefore, this study aimed to explore the modulation of the TLR7/8 pathway by DMA in psoriasis-activated DCs. Models of psoriasis-like skin lesions were established using BALB/c mice; 8 mice were treated with DMA (2.5mg/kg). Bone marrow cells were isolated and induced into DCs using R848, a TLR7/8 agonist. Splenic CD11c+ cells were detected by flow cytometry. Skin CD11c+ cells were detected by immunofluorescence. TLR7, TLR8, MYD88, and IRAKM proteins were detected by Western blot. The effects of DMA on surface molecules of DCs were observed by flow cytometry. mRNA expression of inflammatory factors was detected by qRT-PCR. Secreted cytokines were detected by cytometric bead array. Compared with the model group, psoriasis-like skin lesions were alleviated by DMA, the splenic CD11c+ cells were significantly decreased (P<0.01), and CD11c+ cell numbers in skin lesions were decreased (P<0.01). Expression levels of TLR7, MYD88, and IRAKM were significantly decreased (P<0.05). R848-stimulated DCs showed increased expression of I-A/I-E, CD80, and CD86 (P<0.01), increased IL-23 and IL-1β mRNA and secretion (P<0.05), and increased TLR7, TLR8, MYD88, and IRAKM expression (P<0.01); DMA inhibited all of these effects of the TLR7/8 pathway activation by R848 (P<0.05). In conclusion, DMA could inhibit psoriasis-activated DCs via the TLR7/8 pathway.

Current knowledge on psoriasis and autoimmune diseases

Psoriasis is a prevalent, chronic inflammatory disease of the skin, mediated by crosstalk between epidermal keratinocytes, dermal vascular cells, and immunocytes such as antigen presenting cells (APCs) and T cells. Exclusive cellular “responsibility” for the induction and maintenance of psoriatic plaques has not been clearly defined. Increased proliferation of keratinocytes and endothelial cells in conjunction with APC/T cell/monocyte/macrophage inflammation leads to the distinct epidermal and vascular hyperplasia that is characteristic of lesional psoriatic skin. Despite the identification of numerous susceptibility loci, no single genetic determinant has been identified as responsible for the induction of psoriasis. Thus, numerous other triggers of disease, such as environmental, microbial and complex cellular interactions must also be considered as participants in the development of this multifactorial disease. Recent advances in therapeutics, especially systemic so-called “biologics” have provided new hope for identifying the critical cellular targets that drive psoriasis pathogenesis. Recent recognition of the numerous co-morbidities and other autoimmune disorders associated with psoriasis, including inflammatory bowel disease, multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus suggest common signaling elements and cellular mediators may direct disease pathogenesis. In this review, we discuss common cellular pathways and participants that mediate psoriasis and other autoimmune disorders that share these cellular signaling pathways.

Using Imiquimod-Induced Psoriasis-Like Skin as a Model to Measure the Skin Penetration of Anti-Psoriatic Drugs

Objective

Psoriasis is a chronic inflammatory skin disease and topical therapy remains a key role for treatment. The aim of this study is to evaluate the influence of psoriasis-like lesions on the cutaneous permeation of anti-psoriatic drugs.

Methods

We first set up imiquimod-induced dermatitis in mice that closely resembles human psoriasis lesions. The development of the lesions is based on the IL-23/IL17A axis for phenotypical and histological characteristics. Four drugs, 5-aminolevulinic acid (ALA), tacrolimus, calcipotriol, and retinoic acid, were used to evaluate percutaneous absorption.

Results

The most hydrophilic molecule, ALA, revealed the greatest enhancement on skin absorption after imiquimod treatment. Imiquimod increased the skin deposition and flux of ALA by 5.6 to 14.4-fold, respectively, compared to normal skin. The follicular accumulation of ALA was also increased 3.8-fold. The extremely lipophilic drug retinoic acid showed a 1.7- and 3.8-fold increase in skin deposition and flux, respectively. Tacrolimus flux was enhanced from 2 to 21 μg/cm²/h by imiquimod intervention. However, imiquimod did not promote skin deposition of this macrolide. The lipophilicity, but not the molecular size, dominated drug permeation enhancement by psoriatic lesions. The in vivo percutaneous absorption of ALA and rhodamine B examined by confocal microscopy confirmed the deficient resistance of epidermal barrier for facilitating cutaneous delivery of drugs via psoriasis-like skin.

Conclusion

We established the topical delivery profiles of anti-psoriatic drugs via imiquimod-treated psoriasis-like skin.

A novel water-soluble benzothiazole derivative BD926 inhibits human activated T cell proliferation by down-regulating the STAT5 activation

Immunosuppressants are widely used for treatment of T cell-mediated autoimmune diseases and allogeneic graft rejection. However, because of the toxicity and tolerance of these drugs, novel immunosuppressants are urgently needed. We synthesized a series of novel water-soluble benzothiazole derivatives and found that BD926 [sodium 2-(benzo[d]thiazol-2-yl)-4,5,6,7-tetrahydro-2H-indazol-3-olate] had potent immunosuppressive activity. Treatment with BD926 significantly inhibited anti-CD3/anti-CD28 and alloantigen-induced human T cell proliferation as well as IL2-stimulated activated T cell proliferation in a dose-dependent manner in vitro. BD926 had no obvious cytotoxicity against human resting T cells, IL-4 treated activated T cells and fibroblast-like synoviocytes in our experimental conditions. Furthermore, BD926 induced cell cycle arrest at G0/G1 phase and inhibited the cyclin D3 and CDK 6 expression in activated T cells. BD926 inhibited the STAT5, but not Akt and p70S6K, phosphorylation in a dose-dependent manner in the IL-2-treated activated T cells. Interestingly, BD926 inhibited IFN-γ, IL-6 and IL-17, but not IL-2, IL-4 and IL-10, production in activated T cells. Finally, treatment with BD926 reduced delayed-type hypersensitivity in mice in a dose-dependent manner. Collectively, these data suggest that BD926 may be a lead compound for the design and development of new immunosuppressants for the intervention of allograft rejection and autoimmune diseases.

Extraintestinal manifestations of celiac disease

Case finding for celiac disease (CD) is becoming increasingly common practice and is conducted in a wide range of clinical situations ranging from the presence of gastrointestinal symptoms to failure to thrive in children, prolonged fatigue, unexpected weight loss and anemia. Case finding is also performed in associated conditions, such as autoimmune thyroid disease, dermatitis herpetiformis and type 1 diabetes, as well as in patients with irritable bowel syndrome, unexplained neuropsychiatric disorders and first-degree relatives of patients with diagnosed CD. This aggressive active case finding has dramatically changed the clinical characteristics of newly diagnosed patients. For instance, higher numbers of patients who present with extraintestinal symptoms are now being diagnosed with CD. Current recommendations state that due to a high risk for complications if the disease remains undiagnosed, patients with extraintestinal symptoms due to CD require appropriate diagnosis and treatment. Despite criticism regarding the cost-effectiveness of case finding in CD, such an aggressive approach has been considered cost-effective for high-risk patients. The diagnosis of CD among patients with extraintestinal symptoms requires a high degree of awareness of the clinical conditions that carry a high risk for underlying CD. Also, understanding the correct use of specific serology and duodenal histology is key for an appropriate diagnostic approach. Both procedures combined are able to confirm diagnosis in the vast majority of cases. However, in certain circumstances, serology and even duodenal histology cannot confirm or rule out CD. A common cause of negative IgA serology is IgA deficiency. For such eventuality, IgG-based serological tests can help confirm the diagnosis. Importantly, some histologically diagnosed cases still remain seronegative despite exclusion of IgA deficiency. On the other hand, duodenal histology may be normal despite the presence of CD-specific antibodies and active CD. This has been clearly demonstrated in some cases of untreated dermatitis herpetiformis, but may also be due to the patchy condition of CD or lesions that are not adequately recognized by nonexpert endoscopists and/or pathologists. The effectiveness of agluten-free diet depends on the clinical end point addressed. A good example is the outcome of bone loss. While risk for fracture normalizes after the first year of dietary treatment, bone parameters measured by densitometry may not be normalized in the long-term follow-up. Moreover, it is still unclear how far an early gluten-free diet will positively affect associated autoimmune diseases like type 1 diabetes and autoimmune thyroiditis.

Non-adherence and measures to improve adherence in the topical treatment of psoriasis

Psoriasis is a chronic, recurrent immune-mediated skin disease with a 2-3% prevalence in the Western population, which severely affects patients' quality of life and poses a considerable socioeconomic challenge. The majority of individuals have psoriasis in limited areas and topical products are the mainstay of therapy according to existing guidelines. It is known that medication adherence rates are lower for topical treatment than for systemic treatment. Poor medication adherence is a major multidimensional problem for patients with chronic disorders as it is associated with unfavourable treatment outcomes, increased risk for development of concomitant diseases and inefficient use of health resources. Despite four decades of adherence research and the large number of studies that have identified the importance of medication non-adherence, there are relatively few studies reporting and designing effective strategies to improve adherence. The aim of this article was to report and describe non-adherence in the topical treatment of psoriasis, the factors that might contribute to this phenomenon, and which interventions have so far been developed for the management of chronic conditions. This article proposes that given that the barriers to medication adherence are complex and varied, solutions to improve adherence and thus clinical outcomes must be multifaceted and must also provide the possibility to be tailored according to each patient's individual needs. Such an individualized and comprehensive adherence-enhancing intervention would probably enable the successful long-term management of this disabling chronic condition.

Targeting of interleukin-17 in the treatment of psoriasis

“Psoriasis” is a chronic immune-mediated inflammatory disorder with epidermal hyperplasia. There is some evidence that the cytokine interleukin-17A (often known as IL-17), which is mainly produced by Th17 cells, has a role in the pathogenesis of psoriasis. “IL-17” is a pro-inflammatory cytokine mainly important in the host’s defense against extracellular bacteria and fungi. The three new therapies with biologic drugs – brodalumab, secukinumab, and ixekizumab – all target the IL-17 signaling pathway. Secukinumab and ixekizumab neutralize IL-17A, while brodalumab blocks its receptor. Results from clinical trials have shown marked improvements in disease severity in patients with moderate-to-severe plaque psoriasis, using any of these three drugs. The biologic agents were generally well tolerated, but the duration of the trials was relatively short. In this review, we focus on the role of the IL-17 cytokine family in the pathogenesis of psoriasis; the efficacy, safety, and tolerability of brodalumab, secukinumab, and ixekizumab in clinical trials; and possible differences between targeting of the IL-17A receptor and targeting of the IL-17A ligand.

The emerging role of circulating microRNAs as biomarkers in autoimmune diseases

The highly conserved RNAs known as microRNAs (miRNAs) are a class of small, single-stranded, non-coding RNAs that play a critical role in the regulation of host genome expression at the posttranscriptional level. MiRNA-mediated gene regulation is vital for normal cellular functions, such as the cell differentiation, proliferation and apoptosis, and nearly one-third of human messenger RNAs might be miRNA targets. Increasing evidence has suggested that miRNAs play a critical role in the regulating the immune system and preventing autoimmune disorders. Circulating miRNAs, which can be easily detected by a non-invasive methods, have been proven to be able to distinguish diseased individuals from healthy subjects. In addition, these circulating miRNAs have relatively high sensitivity and specificity and thus have been developed as biomarkers for the diagnosis and monitoring of human diseases. To date, nearly 100 circulating miRNAs have been proven to be biomarkers for various diseases, and this number continues to rise. This review aims to summarize the most promising identified circulating miRNAs as potential biomarkers in autoimmune diseases and to discuss current challenges and future directions in the field.

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

Psoriasis is a common chronic relapsing inflammatory cutaneous disease; the main role in the inflammation of this condition is played by lymphocyte Th1, Th17 and their cytokines. The activity of these cells is modulated by a particular kind of T cells recently described: the T regulatory cells (Treg). These are able to inhibit the immunological response and to maintain the cutaneous immunological homeostasis, thus preventing autoimmunity against self antigens. Few data are available in the literature as to Treg in psoriasis; several studies demonstrate that the function of these cells is impaired in this condition and treatments for psoriasis may increase the number and activity of Treg. The role of these cells in the pathogenesis of psoriasis is very important to understand how they may contribute to the development of this cutaneous disorder. In the near future it would be possible to target therapies at these defects, improving the activity of these cells and maintaining cutaneous homeostasis, preventing psoriasis or other inflammatory cutaneous conditions.

Lifting the silver flakes: the pathogenesis and management of chronic plaque psoriasis

Psoriasis is a common chronic inflammatory skin condition in which patients suffer from mild to chronic plaque skin plaques. The disease manifests through an excessive inflammatory response in the skin due to complex interactions between different genetic and environmental factors. Psoriasis can affect the physical, emotional, and psychosocial well-being of patients, and currently there is no cure with treatments focusing primarily on the use of anti-inflammatory agents to control disease symptoms. Traditional anti-inflammatory agents can cause immunosuppression and adverse systemic effects. Further understanding of the disease has led to current areas of research aiming at the development of selective molecular targets to suppress the pathogenic immune responses.

Expression patterns of Th1/Th2 transcription factors in patients with guttate psoriasis

Many lines of evidence propose that psoriasis is a T cell-mediated disease where T cell activation is followed by secretion of inflammatory cytokines. To elucidate the functional state of T cells in guttate psoriasis, we analysed mRNA expression levels of T-bet and GATA-3 for Th1 and Th2 differentiation, respectively together with Th1 (IFN-γ) and Th2 (IL-4) cytokine mRNA expression. Relative quantification of T-bet, GATA-3, IFN-γ and Th2, and IL-4 transcripts in peripheral blood leukocytes (PBL) was conducted by real-time reverse transcriptase PCR (RT-PCR). Serum levels of IFN-γ and Th2 and IL-4 were also determined by ELISA. GATA-3 and IL-4 mRNA expression levels were lower in psoriatic patients as compared to normal healthy controls. The expression levels of T-bet and IFN-γ and Th2 genes were relatively similar in the patients and controls. In addition, a marked decrease in plasma IL-4 levels was observed in the psoriasis group, while no differences were observed with regard to levels of IFN-γ and Th2 between patients and normal subjects. Furthermore, a clear correlation between decreased IL-4 mRNA expression and IL-4 (P < 0.05) was revealed. These results suggested that altered balance between Th1 and Th2 cells transcription factor genes and they products may be implicated in the pathogenesis of psoriasis.

Amygdalin analogs for the treatment of psoriasis

Psoriasis is one of the most prevalent immune-mediated illness worldwide. The disease can still only be managed rather than cured, so treatments are aimed at clearing skin lesions and preventing their recurrence. Several treatments are available depending on the extent of the psoriatic lesion. Among the topical treatments corticostereoids, vitamin D3 analogs and retinoids are commonly used. However, these treatments may have adverse effects in the long term. Conversely, systemic conventional treatments include immunosuppresors such as cyclosporin or methotrexate associated with high toxicity levels. Biologicals are alternative therapeutical agents introduced in the last 10 years. These include fusion proteins or monoclonal antibodies designed to inhibit the action of specific cytokines or to prevent T-lymphocyte activation. However, due to recent knowledge on the etiology of the disease, diverse new small molecules have appeared as promising alternatives for the treatment of psoriasis. Among them, inhibitors of JAK3, inhibitors of PDE 4 and amygdalin analogs. The latter are promising small molecules presently in preclinical studies which are the object of the present report.