NF-κB and STAT3 inhibition as a therapeutic strategy in psoriasis: in vitro and in vivo effects of BTH

Gypenosides alleviates HaCaT keratinocyte hyperproliferation and ameliorates imiquimod-induced psoriasis in mice

BACKGROUND

Psoriasis is an autoimmune skin condition characterized by hyperproliferation of keratinocytes and chronic immune responses. Gypenosides (Gyp) exhibits anti-proliferative and anti-inflammatory effects on different diseases. However, its functioning and mechanism of Gyp on psoriasis remains unknown.

OBJECTIVE

To explore the effect and mechanism of Gyp on psoriasis.

MATERIAL AND METHODS

The impact and mechanism of Gyp on psoriasis in vitro and in vivo were probed through cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, reverse transcription quantitative polymerase chain reaction, hematoxylin and eosin staining, enzyme-linked immunosorbent serologic assay, immunofluorescence, and Western Blotting assays.

RESULTS

Gyp inhibited cell proliferation and the release of inflammatory cytokinesin interleukin (IL-22)-induced spontaneously transformed human aneuploid immortal keratinocyte cell line (HaCaT). In addition, Gyp demonstrated enhancement in erythema and scaling as well as reductions in the thickness of epidermal layers, release of inflammatory factors, and Ki-67 (a nuclear protein) level in imiquimod (IMQ)-induced mice. Mechanistically, Gyp upregulated nuclear factor erythroid 2-related factor 2 (Nrf-2) expression and diminished the level of p-p65/p65 and p-STAT3/STAT3 in skin tissues from IMQ-induced mice and IL-22-induced HaCaT cells, which were reversed with the application of ML385, an inhibitor of Nrf2. In addition, the administration of ML385 reversed decrease in cell viability and reduced the expressions of IL-1β, IL-6, and tumor necrosis factor-α (TNF-α) in IL-22-induced HaCaT cells caused by Gyp.

CONCLUSION

In summary, Gyp reduced excessive cell growth and inflammation in psoriasis by suppressing nuclear factor kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) through activation of Nrf2.

Preclinical techniques for drug discovery in psoriasis

Psoriasis is a chronic, inflammatory, papulosquamous, noncontagious disease characterized by scaly, demarcated erythematous plaque, affecting skin, nails, and scalp. The IL-23/Th17 axis is the main operator in the development of psoriasis. Psoriasis is affecting worldwide, and new treatment options are urgently needed. Various local and systemic treatments are available for psoriasis but they only provide symptomatic relief because of numerous unknown mechanisms. Clinical trials demand overwhelming resources; therefore, drug development predominantly depends on the in-vivo, in-vitro, and ex-vivo techniques. Immediate attention is required to develop experimental techniques that completely imitate human psoriasis to assist drug development. This review portrays the various in-vivo, in-vitro, and ex-vivo techniques used in psoriasis research. It describes these techniques' characteristics, pathological presentations, and mechanisms. The experimental techniques of psoriasis provide significant information on disease progression mechanisms and possible therapeutic targets. However, until now, it has been challenging to invent a timely, affordable model that precisely imitates a human disease. Only the xenotransplantation model is reckoned as the closer, that mimics the complete genetic, and immunopathogenic event. Imiquimod-induced psoriasis and HaCat cell lines are popular among researchers because of their convenience, ease of use, and cost-effectiveness. There need to further improve the experimental techniques to best serve the disease imitation and meet the research goal.

Cang-ai volatile oil ameliorates imiquimod-induced psoriatic skin lesions by suppressing the ILC3s

ETHNOPHARMACOLOGICAL RELEVANCE

Cang-ai volatile oil (CAVO) is an aromatic Chinese medicine with potent antibacterial and immune regulatory properties. While CAVO has been used to treat upper respiratory tract infections, depression, otomycosis, and bacterial infections in the skin, its effect on psoriasis is unknown.

AIM OF THE STUDY

This study explores the effect and mechanism of CAVO in psoriasis intervention.

MATERIAL AND METHODS

The effect of CAVO on the expression of IL-6 and IL-1β was assessed in TNF-α-induced HaCaT cells using enzyme-linked immunosorbent assay (ELISA). Mice were given imiquimod (IMQ) and administered orally with different CAVO doses (0.03 and 0.06 g/kg) for 5 days. The levels of inflammatory cytokines related to group-3 innate lymphoid cells (ILC3s) in the skin were assessed using hematoxylin and eosin (H&E) staining, ELISA, and western blotting (WB). The frequency of ILC3s in mice splenocytes and skin cells was evaluated using flow cytometry.

RESULTS

The results demonstrated that CAVO decreased the expression of IL-6 and IL-1β in TNF-α- induced HaCaT cells. CAVO significantly reduced the severity of psoriatic symptoms in IMQ-induced mice. The expression of inflammatory cytokines in the skin, such as IL-1β, IL-6, IL-8, IL-22, IL-23, and IL-17 A were decreased, whereas IL-10 levels were increased. The mRNA expressions of TNF-α, IL-23 A, IL-23 R, IL-22, IL-17 A, and RORγt were down-regulated in skin tissues. CAVO also decreased the levels of NF-κB, STAT3, and JAK2 proteins.

CONCLUSIONS

CAVO potentially inhibits ILC3s activation to relieve IMQ-induced psoriasis in mice. These effects might be attributed to inhibiting the activation of NF-κB, STAT3, and JAK2 signaling pathways.

Adenosine A2B receptor agonist improves epidermal barrier integrity in a murine model of epidermal hyperplasia

Adenosine regulates multiple physiological processes through the activation of four receptor subtypes, of which the A2B adenosine receptor (A2BAR) has the lowest affinity for adenosine. Being the adenosine receptor subtype most prominently expressed in epidermis, we recently described the antiproliferative and anti-inflammatory effect of the selective A2BAR agonist BAY60-6583 (BAY) in human keratinocytes stimulated with 12-O-tetradecanoylphorbol-13-acetate (TPA), so we sought to establish the effect of topical application of BAY in a model of murine epidermal hyperplasia. Topical application of BAY (1 or 10 μg/site) prevented the inflammatory reaction and skin lesions induced by TPA, minimizing hyperproliferation and acanthosis, as well as the expression of specific markers of proliferative keratinocytes. On the other hand, pre-treatment with the selective A2BAR antagonist, PSB-1115 (PSB, 5 or 50 μg/site) reversed these beneficial effects. Additionally, BAY application normalized the expression of epidermal barrier proteins, whose integrity is altered in inflammatory skin diseases, while treatment with the antagonist alone worsened it. Our results, besides confirming the anti-inflammatory and antiproliferative effects of the A2BAR agonist, further demonstrate a role of A2BAR activation to preserve the epidermal barrier. Therefore, the activation of A2BAR may constitute a possible new pharmacological target for the treatment of skin inflammatory diseases such as psoriasis.

WB518, a novel STAT3 inhibitor, effectively alleviates IMQ and TPA-induced animal psoriasis by inhibiting STAT3 phosphorylation and Keratin 17

OBJECTIVES

Psoriasis is a prevalent chronic inflammatory skin disease in humans that is characterized by frequent relapses and challenging to cure. WB518 is a novel small molecule compound with an undisclosed structure. Therefore, our study aimed to investigate the therapeutic potential of WB518 in vitro and in vivo for the treatment of psoriasis, specifically targeting the abnormal proliferation, aberrant differentiation of epidermal keratinocytes, and pathogenic inflammatory response.

MATERIALS AND METHODS

We employed dual luciferase reporter assay to screen compounds capable of inhibiting STAT3 gene transcription. Flow cytometry was utilized to analyze CD3-positive cells. Protein and mRNA levels were assessed through Western blotting, immunofluorescence, immunohistochemistry, and real-time PCR. Cell viability was measured using the MTS assay, while in vivo models of psoriasis induced by IMQ and TPA were employed to study the anti-psoriasis effect of WB518.

RESULTS

WB518 was found to significantly reduce the mRNA and protein levels of Keratin 17 (K17) in HaCaT cells by inhibiting the phosphorylation of STAT3 Tyr705 (Y705). In the IMQ and TPA-induced psoriasis mouse model, WB518 effectively improved scaling, epidermal hyperplasia, and inflammation. WB518 also suppressed the expression of inflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-17, and IL-23. Furthermore, WB518 decreased the proportion of CD3-positive cells in the psoriatic skin of mice.

CONCLUSIONS

WB518 exhibits promising potential as a treatment candidate for psoriasis.

Natural STAT3 Inhibitors for Cancer Treatment: A Comprehensive Literature Review

Cancer is one of the leading causes of mortality and morbidity worldwide, affecting millions of people physically and financially every year. Over time, many anticancer treatments have been proposed and studied, including synthetic compound consumption, surgical procedures, or grueling chemotherapy. Although these treatments have improved the daily life quality of patients and increased their survival rate and life expectancy, they have also shown significant drawbacks, including staggering costs, multiple side effects, and difficulty in compliance and adherence to treatment. Therefore, natural compounds have been considered a possible key to overcoming these problems in recent years, and thorough research has been done to assess their effectiveness. In these studies, scientists have discovered a meaningful interaction between several natural materials and signal transducer and activator of transcription 3 molecules. STAT3 is a transcriptional protein that is vital for cell growth and survival. Mechanistic studies have established that activated STAT3 can increase cancer cell proliferation and invasion while reducing anticancer immunity. Thus, inhibiting STAT3 signaling by natural compounds has become one of the favorite research topics and an attractive target for developing novel cancer treatments. In the present article, we intend to comprehensively review the latest knowledge about the effects of various organic compounds on inhibiting the STAT3 signaling pathway to cure different cancer diseases.

Etanercept ameliorates psoriasis progression through regulating high mobility group box 1 pathway

BACKGROUND

As a common skin disease, psoriasis is related to inflammation and immune response. Due to the frequent recurrence of psoriasis, the treatment of psoriasis remains a clinical challenge. As an effective tumor necrosis factor-alpha (TNF-α) inhibitor, etanercept has been used for the treatment of psoriasis. However, some patients with psoriasis have no response to etanercept or discontinue treatment. To improve the therapeutic effect of etanercept, searching the potential biomarkers and investigating the related mechanisms of etanercept in the treatment of psoriasis are vital.

MATERIALS AND METHODS

We stimulated HaCaT cells with lipopolysaccharide (LPS) to generate cellular psoriatic changes and established an imiquimod (IMQ)-induced psoriasis-like mouse model, and then used an etanercept to treat cell and mouse model.

RESULTS

Etanercept alleviated IMQ-induced pathological changes and inflammation, and it also decreased the protein expression of high mobility group box 1 (HMGB1), receptor for advanced glycation end-products, and toll-like receptor 4. Moreover, the results of in vitro experiments showed that etanercept inhibited proliferation and inflammation, and promoted cell cycle arrest and apoptosis in LPS-treated HaCaT cells. Knockdown of HMGB1 further enhanced the inhibitory effects of etanercept on LPS-treated HaCaT cell viability and inflammation, while overexpression of HMGB1 notably reversed the inhibitory effects of etanercept on LPS-induced HaCaT cell viability and inflammation.

CONCLUSION

Etanercept inhibited proliferation and inflammation and promoted cell cycle arrest and apoptosis in LPS-induced HaCaT cells, and etanercept ameliorated inflammation in a psoriasis-like mouse model.

Gallic acid diminishes pro-inflammatory interferon-γ- and interleukin-17-producing sub-populations in vitro in patients with psoriasis

Psoriasis is an inflammation of the skin mediated via the IL-23/Thl17/IL-17 pathway. We have previously demonstrated that the anthocyanin delphinidin diminishes in vitro the IL-17 and IFN-γ production of peripheral monocytes isolated by psoriasis patients (PBMCs). The degradation product of delphinidin is gallic acid (GA). This phenolic acid compound found in fruits, red wine, or green tea exerts pleiotropic antioxidant, anticarcinogenic, antimicrobial, and anti-inflammatory properties. Previous research has demonstrated the inhibitory effect of GA on pro-inflammatory transcription factors, such as STAT3, RORγt, and NF-κB, or cytokines as IL-1β and TNF, which contribute to psoriasis development. We investigated the effect of GA in vitro on PBMCs, which were stimulated ex vivo, from 40 individuals (28 diagnosed with psoriasis vulgaris and 12 healthy controls (HCs)). In our experiments, PBMCs were cultured untreated or were activated in the presence of phorbol 12-myristate 13-acetate/ionomycin with or without GA. We utilized multicolor flow cytometry to assess the production of inteleukin-17 (IL-17) and interferon-γ (IFN-γ) in T and NK cells. GA did not alter the fractions of IL-17- or IFN-γ-producing T and IFN-γ-producing NK cells in HCs. However, in psoriasis patients, the effect of GA on that cell population was significant. Specifically, GA decreased the frequency of IL-17-producing cells within the CD3⁺ (T) and CD3⁺CD4⁺ (Th) compartment; the frequency of IFN-γ-producing cells within the CD3⁺, CD3⁺CD4⁺, and CD3⁺CD4^- (Tc) compartment, and the frequency of IFN-γ-producing cells within the CD3^-CD56⁺ (NK) compartment. Whether GA's effect also appears in vivo needs to be investigated in future.

Novel RNA polymerase I inhibitor CX-5461 suppresses imiquimod-induced experimental psoriasis

Clinical treatment of psoriasis remains challenging because of possible long-term drug toxicities and loss of therapeutic effects over time. CX-5461 is a novel selective inhibitor of RNA polymerase I. Our previous studies have shown that CX-5461 has potent anti-inflammatory effects. Here we investigated whether CX-5461 could inhibit the development of imiquimod-induced experimental psoriasis in mice. Adult male C57BL/6 mice were used, and psoriasis-like lesions were induced by topical imiquimod treatment. In vivo, we demonstrated that topical application of CX-5461 prevented the development of imiquimod-induced psoriasis, with decreases in keratinocyte proliferation, T-cell infiltration and pathological angiogenesis. CX-5461 also reversed existing skin inflammation induced imiquimod and retarded the development of 12-O-tetradecanoylphorbol-13-acetate-induced epidermal hyperplasia and inflammation. In vitro, CX-5461 induced cell cycle arrest in keratinocytes, inhibited expressions of interleukin-17, interleukin-23 receptor and retinoic acid receptor-related orphan receptor-γt in activated T cells, and reduced angiogenic functions of endothelial cells. In conclusion, CX-5461 exhibits therapeutic effects on experimental psoriasis in mice, likely via multiple mechanisms including anti-proliferative, anti-inflammatory and anti-angiogenic activities.

Anti-Psoriatic Effect of Rheum palmatum L. and Its Underlying Molecular Mechanisms

Psoriasis is a chronic, immune-mediated inflammatory skin disorder. Rheum palmatum L. is a common traditional medicinal herb with anti-inflammatory and immunomodulatory activities. This study aimed to investigate the anti-psoriatic effects of the ethanolic extract from R. palmatum L. (RPE) and its chemical constituents, as well as the mechanisms underlying their therapeutic significance. An imiquimod (IMQ)-induced psoriasis-like mouse model was used to examine the anti-psoriatic effect of RPE in vivo. Network pharmacological analysis was performed to investigate the potential targets and related pathways of the RPE components, including rhein, emodin, chrysophanol, aloe-emodin, and physcion. The anti-inflammatory effects and underlying mechanisms of these components were examined using in vitro models. Topical application of RPE alleviated psoriasis-like symptoms and reduced levels of inflammatory cytokines and proliferation markers in the skin. Network pharmacological analysis revealed that RPE components target 20 genes that are linked to psoriasis-related pathways, such as IL-17, MAPK, and TNF signaling pathways. Among the five components of RPE, rhein and emodin showed inhibitory effects on TNF-α and IL-17 production in EL-4 cells, attenuated the production of CXCL8, CXCL10, CCL20, and MMP9, and reduced proliferation in HaCaT cells. Chrysophanol, aloe-emodin, and physcion were less effective than rhein and emodin in suppressing inflammatory responses and keratinocyte proliferation. The effects of these compounds might occur through the inhibition of the ERK, STAT3, and NF-κB signaling pathways. This study suggested the anti-psoriatic effect of RPE, with rhein and emodin as the main contributors that regulate multiple signaling pathways.

miR-124-3p Delivered Using Exosomes Attenuates the Keratinocyte Response to IL-17A Stimulation in Psoriasis

Methods

NHEKs, HaCaT cells, and HEK 293T cells were treated with IL-17A. CCK-8 assays were performed to detect cell activity, and immunofluorescence staining and Western blotting were performed to detect the protein expression of STAT3. After isolation of exosomes via ultracentrifugation, the contents of miR-124-3p and oxidative stress markers such as superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in keratinocytes were measured. Subsequently, transcriptomic analysis was performed using RNA-seq. Data were analysed by using the “edgeR” package within R. After verifying the abnormally expressed genes stimulated by IL-17A, a dual luciferase reporter assay was used to determine the interaction between miR-124-3p and STAT3. Finally, BALB/c mice were used to establish a psoriasis model for analysis. The effect of elevated miR-124-3p on the psoriasis mouse model was determined by exosomal delivery of miR-124-3p.

Results

IL-17 intervention enhanced the cell activity of keratinocytes (P < 0.05). miR-124-3p was identified by RNA-seq as one of the differentially expressed miRNAs stimulated by IL-17A. miR-124-3p overexpression induced decreased STAT3 and MDA levels, increased SOD and GSH-Px levels in keratinocytes, and alleviated emergency responses of sclerosis damage (P < 0.05). The dual luciferase reporter assay results confirmed that STAT3 was regulated by miR-124-3p in a targeted manner (P < 0.05). Finally, miR-124-3p delivered by exosomes effectively alleviated the pathological manifestations and oxidative stress responses of psoriatic mice.

Conclusions

miR-124-3p regulates keratinocyte activity via STAT3 in response to IL-17A stimulation. The ectopic expression of miR-124-3p in psoriatic skin reduces IL-17A-induced inflammation and inhibits the STAT3 pathway, thus alleviating the symptoms of psoriasis. The findings of this study suggest that exosomes can be used to therapeutically deliver miR-124-3p to keratinocytes and psoriatic lesions, which may provide novel insight for psoriasis treatment.

Scarless wound healing: Current insights from the perspectives of TGF-β, KGF-1, and KGF-2

The process of wound healing involves a complex and vast interplay of growth factors and cytokines that coordinate the recruitment and interaction of various cell types. A series of events involving inflammation, proliferation, and remodeling eventually leads to the restoration of the damaged tissue. Abrogation in the regulation of these events has been shown to result in excessive scarring or non-healing wounds. While the process of wound healing is not fully elucidated, it has been documented that the early events of wound healing play a key role in the outcome of the wound. Furthermore, high levels of inflammation have been shown to lead to scarring. The regulation of these events may result in scarless wound healing, especially in adults. The inhibition of transforming growth factor-β (TGF-β) and the administration of keratinocyte growth factors (KGF), KGF-1 and KGF-2, has in recent years yielded positive results in the acceleration of wound closure and reduced scarring. Here, we encapsulate recent knowledge on the roles of TGF-β, KGF1, and KGF2 in wound healing and scar formation and highlight the areas that need further investigation. We also discuss potential future directions for the use of growth factors in wound management.

Coptisine Alleviates Imiquimod-Induced Psoriasis-like Skin Lesions and Anxiety-like Behavior in Mice

Psoriasis is a common inflammatory skin disorder, which can be associated with psychological disorders, such as anxiety and depression. This study investigated the efficacy and the mechanism of action of a natural compound coptisine using imiquimod (IMQ)-induced psoriasis mice. Coptisine reduced the severity of psoriasis-like skin lesions, decreased epidermal hyperplasia and the levels of inflammatory cytokines TNF-α, IL-17, and IL-22. Furthermore, coptisine improved IMQ-induced anxiety in mice by increasing the number of entries and time in open arms in the elevated plus maze (EPM) test. Coptisine also lowered the levels of inflammatory cytokines TNF-α and IL-1β in the prefrontal cortex of psoriasis mice. HaCaT keratinocytes and BV2 microglial cells were used to investigate the effects of coptisine in vitro. In M5-treated HaCaT cells, coptisine decreased the production of IL-6, MIP-3α/CCL20, IP-10/CXCL10, and ICAM-1 and suppressed the NF-κB signaling pathway. In LPS-stimulated BV2 cells, coptisine reduced the secretion of TNF-α and IL-1β. These findings suggest that coptisine might be a potential candidate for psoriasis treatment by improving both disease severity and psychological comorbidities.

P. granatum Peel Polysaccharides Ameliorate Imiquimod-Induced Psoriasis-Like Dermatitis in Mice via Suppression of NF-κB and STAT3 Pathways

Psoriasis is a chronic and refractory inflammatory and autoimmune-mediated cutaneous disease affecting approximately 2%–3% of the global population. Most of the current therapies could relieve symptoms rapidly, while the side effects cannot be negligible. Hence, it is urgent to explore much safer and more effective treatments. In the current work, we evaluated the potential beneficial effect of Punica granatum peel polysaccharides (PPPs) in an imiquimod-elicited psoriasis-like mouse model and unraveled their mechanism of action. Firstly, PPPs were isolated from P. granatum peels, and then the molecular weight was determined and monosaccharide analysis was performed. The results revealed that PPPs significantly ameliorated psoriasis-like skin lesions and reduced the Psoriasis Area and Severity Index (PASI) scores and transepidermal water loss (TEWL). PPPs also attenuated the expressions of CD3 and Ki67 in psoriasis-like mouse skin and suppressed the serum or skin levels of pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), IL-1β, IL-8, IL-17, and IL-23. Moreover, PPPs were able to upregulate the mRNA and protein expressions of aquaporin-3 (AQP3) and filaggrin (FLG) in the skin of mice. In addition, PPPs inhibited the NF-κB and STAT3 signaling pathways. Overall, these results indicated that PPPs ameliorated the symptoms of psoriasis through inhibition of the inflammatory cytokines by suppressing the NF-κB and STAT3 signaling pathways and improved skin barrier protection via enhancing AQP3 and FLG. These observations potentially contribute to providing theoretical and experimental evidence for the clinical application of PPPs for psoriasis.

Identification of Keratinocyte Mitogens: Implications for Hyperproliferation in Psoriasis and Atopic Dermatitis

Psoriasis and atopic dermatitis are chronic inflammatory skin diseases characterized by keratinocyte (KC) hyperproliferation and epidermal acanthosis (hyperplasia). The milieu of disease-associated cytokines and soluble factors is considered a mitogenic factor; however, pinpointing the exact mitogens in this complex microenvironment is challenging. We employed organotypic human epidermal equivalents, faithfully mimicking native epidermal proliferation and stratification, to evaluate the proliferative effects of a broad panel of (literature-based) potential mitogens. The KC GF molecule, the T-helper 2 cytokines IL-4 and IL-13, and the psoriasis-associated cytokine IL-17A caused acanthosis by hyperplasia through a doubling in the number of proliferating KCs. In contrast, IFN-γ lowered proliferation, whereas IL-6, IL-20, IL-22, and oncostatin M induced acanthosis not by hyperproliferation but by hypertrophy. The T-helper 2‒cytokine‒mediated hyperproliferation was Jak/signal transducer and activator of transcription 3 dependent, whereas IL-17A and KC GF induced MAPK/extracellular signal‒regulated kinase kinase/extracellular signal‒regulated kinase‒dependent proliferation. This discovery that key regulators in atopic dermatitis and psoriasis are direct KC mitogens not only adds evidence to their crucial role in the pathophysiological processes but also highlights an additional therapeutic pillar for the mode of action of targeting biologicals (e.g., dupilumab) or small-molecule drugs (e.g., tofacitinib) by the normalization of KC turnover within the epidermal compartment.

Perillyl alcohol inhibits keratinocyte proliferation and attenuates imiquimod-induced psoriasis like skin-inflammation by modulating NF-κB and STAT3 signaling pathways

Psoriasis is a chronic inflammatory and proliferative skin disease characterized by pathological skin lesions which significantly impact the quality of life. Recent studies have been proven that inhibitors of farnesyltransferase enzyme showed significant anti-psoriatic activity. Perillyl alcohol (POH) is one such natural molecule having anti proliferative, anti-inflammatory and anti-oxidant properties by inhibiting farnesyltransferase enzyme which further down regulates NF-κB and STAT3 via Ras/Raf/MAPK pathway. Hence, in the current study we aimed to find the effect of POH on human keratinocytes (HaCat) cells in in-vitro and IMQ induced psoriatic like skin inflammation model in mice. POH significantly decreased the intracellular ROS levels and inhibited the phosphorylation of NF-κB and STAT3 in in-vitro. It was found that POH (200 mg/kg, topical application) has reduced the epidermal hyperplasia, psoriasis area and severity index (PASI) scoring; splenomegaly in imiquimod (IMQ) induced psoriatic mice. Further, POH treatment has decreased the pro-inflammatory serum cytokine levels such as IL-6, IL-12/23, TNF-α and IL-1β and also reduced the expression levels of various inflammatory proteins, COX-2, iNOS, IL-17A, IL-22, NF-кB and STAT3 evidenced by Immunoblotting studies from skin samples. The levels of endogenous antioxidants like glutathione GSH, SOD, Nrf2 were restored to normal levels upon POH treatment. POH downregulated the proteins levels of TLR7, TLR8, CyclinD1 and mRNA expression of Bcl-2 in the skin samples when compared to the IMQ group. POH has ameliorated the hyper-keratosis and acanthosis which was evidenced by histopathology. Collectively, our results suggest that POH has a promising therapeutic application for ameliorating psoriasis-like skin inflammation.

Logical and experimental modeling of cytokine and eicosanoid signaling in psoriatic keratinocytes

Psoriasis is a chronic skin disease, in which immune cells and keratinocytes keep each other in a state of inflammation. It is believed that phospholipase A2 (PLA2)-dependent eicosanoid release plays a key role in this. T-helper (Th) 1-derived cytokines are established activators of phospholipases in keratinocytes, whereas Th17-derived cytokines have largely unknown effects. Logical model simulations describing the function of cytokine and eicosanoid signaling networks combined with experimental data suggest that Th17 cytokines stimulate proinflammatory cytokine expression in psoriatic keratinocytes via activation of cPLA2α-Prostaglandin E2-EP4 signaling, which could be suppressed using the anti-psoriatic calcipotriol. cPLA2α inhibition and calcipotriol distinctly regulate expression of key psoriatic genes, possibly offering therapeutic advantage when applied together. Model simulations additionally suggest EP4 and protein kinase cAMP-activated catalytic subunit alpha as drug targets that may restore a normal phenotype. Our work illustrates how the study of complex diseases can benefit from an integrated systems approach.

Leucosceptoside A from Devil's Claw Modulates Psoriasis-like Inflammation via Suppression of the PI3K/AKT Signaling Pathway in Keratinocytes

Psoriasis is a chronic inflammatory skin condition characterized by abnormal keratinocyte proliferation and differentiation that is accompanied with dysregulated immune response and abnormal vascularization. Devil’s claw (Harpagophytum procumbens (Burch.) DC. ex Meisn.) tubers extract has been used both systemically and topically for treatment of chronic inflammatory diseases such as arthritis, osteoporosis, inflammatory bowel disease, among others. However, its potential mechanisms of action against psoriasis remains poorly investigated. The human keratinocyte HaCaT cell line is a well-accepted in vitro model system for inflammatory skin disorders such as psoriasis. The present study involved an exploration of the effect of biotechnologically produced H. procumbens (HP) cell suspension extract and pure phenylethanoid glycosides verbascoside (VER) and leucosceptoside A (LEU) in interferon (IFN)-γ/interleukin (IL)-17A/IL-22-stimulated HaCaT cells as a model of psoriasis-like inflammation. Changes in key inflammatory signaling pathways related to psoriasis development were detected by reverse transcription polymerase chain reaction and western blotting. Treatment with LEU, but not VER and HP extract improved psoriasis-related inflammation via suppression of the PI3K/AKT signaling in IFN-γ/IL-17A/IL-22-stimulated HaCaT cells. Our results suggest that LEU may exhibit therapeutic potential against psoriasis by regulating keratinocyte differentiation through inhibition of the PI3K/AKT pathway.

Anti-Psoriatic Effects of Antimony Compounds In Vitro

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation of keratinocytes and a pro-inflammatory milieu in the skin. While patients with moderate to severe psoriasis are treated using targeted therapies (small molecules and monoclonal antibodies), patients suffering from milder forms are still in need of effective topical products without adverse effects. Antimony compounds (ACs) are regularly used as anti-inflammatory compounds in traditional and anthroposophic medicine and as antiprotozoan drugs. Here, we examined the effect of metallic antimony, natural antimony(III) sulfide and potassium antimonyl(III) tartrate in vitro on psoriasis-like keratinocytes and the human dendritic cell line THP-1 using qPCR, immunocytochemistry, ELISA and flow cytometry. In psoriatic keratinocytes, ACs inhibited the overexpression of the antimicrobial peptide β-defensin 2 and glucose transporter 1, as well as the hyperproliferation marker keratin 17. Furthermore, ACs mediated anti-inflammatory effects by reducing nuclear translocation of the p65 subunit of NF-κB and pSTAT3 and inhibited pro-inflammatory cytokine secretion by keratinocytes. In addition, ACs displayed anti-psoriatic effects by reducing the activation of IFN-α-treated THP-1 cells as well as the expression of the psoriasis-promoting master cytokine IL-23 by these cells. While all ACs showed anti-psoriatic effects, the most prominent results were seen with potassium antimonyl(III) tartrate. In summary, ACs display numerous anti-psoriatic effects in vitro at subtoxic concentrations. We conclude that ACs are interesting compounds for the topical treatment of psoriasis that warrant further investigation in clinical studies.

Delivery and Anti-Psoriatic Effect of Silibinin-Loaded Polymeric Micelles: An Experimental Study in the Psoriatic Skin Model

OBJECTIVE

Psoriasis is an inflamed skin disorder associated with the activation of phosphorylation signals in keratinocytes, which leads to proliferation. Phosphorylation signal inhibitors, such as silibinin can inhibit cell proliferation. Unlike current psoriasis treatment approaches that are associated with dangerous side effects; natural components can introduce new trends in psoriasis treatment. The major problem in the topical treatment of psoriasis is drug localization through the psoriasis lesions.

METHODS

In this study, silibinin-loaded polymeric micelles prepared and characterized for drug loading and release and ex vivo permeation through psoriatic and normal mice skin. The optimized batch was used for the treatment of psoriasis lesions in the mice model.

RESULTS

The optimized batch demonstrated mean particle size 18.3 ± 2.1 nm, entrapment efficiency 75.8 ± 5.8%, and prolonged silibinin release. % Silibinin permeated through psoriatic skin after 48 treated by polymeric micelle and aqueous control was 80.35, and 92.6, respectively. Polymeric micelles increased silibinin localization in the psoriatic skin in comparison with control. In psoriatic skin after 7- 10 days treatment by silibinin- loaded polymeric micelle, there was no evidence of psoriasis and the histological evaluation showed no sign of psoriasis. Silibinin-loaded polymeric micelles reduced Psoriasis area index by more than 78% after 14 days.

CONCLUSION

It seems that polymeric micelles increased the effectiveness of silibinin by drug localization into the psoriatic plaque. Topical STAT- 3inhibitors can be introduced as a new strategy in psoriasis treatment.

Galangin ameliorates Imiquimod-Induced psoriasis-like skin inflammation in BALB/c mice via down regulating NF-κB and activation of Nrf2 signaling pathways

Psoriasis is a most common chronic autoimmune-arbitrated cutaneous inflammatory skin disorder by unclear pathogenesis. In this current study we demonstrated the effect of galangin (GAL) on imiquimod (IMQ)-induced psoriasis-like skin inflammation and decipher its possible protective mechanism which has not been investigated. The in vivo results revealed that GAL at 1% w/w and 2% w/w for six consecutive days markedly reduced IMQ-induced PASI scoring, skin, ear thickness, hematological markers, levels of nitrites, TBARS, MPO, histopathological, as well modulated the protein levels of pro-inflammatory mediators of COX-2, iNOS, NF-κB pathway and pro-inflammatory cytokines IL-17, IL-23, IL-1β in the skin and also IL-6, TNF-α in both skin and serum. Besides, GAL restored the levels of antioxidants markers such as SOD, CAT, GST, GSH, GR and Vit-C, anti-inflammatory cytokine of IL-10, and the protein levels of Nrf2/HO-1 in the skin compared to the IMQ group. Finally, our study demonstrates that GAL exerted its protective effect by up-regulating the anti-inflammatory and the antioxidant markers against psoriasis pre-clinical models indicating its potency for treating psoriasis in humans.

Protectin D1 reduces imiquimod-induced psoriasiform skin inflammation

Specialized proresolving mediators are enzymatically oxygenated natural molecules derived from polyunsaturated fatty acids and are considered novel. These novel mediators include lipoxins from arachidonic acid, resolvins and protectins from omega-3 essential fatty acids, and new maresins. These mediators harbor potent dual proresolving and anti-inflammatory properties. Resolvins and protectins are known to be potent when administered to various inflammation-associated animal models of human diseases. Although psoriasis' etiology remains unknown, there is accumulating evidence indicating that cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL)-23, and IL-17, play pivotal roles in its development. Experimentally, resolvins, maresins, and lipoxins downregulate the cytokine expression of the IL-23/IL-17 axis and inhibition of mitogen-activated protein kinases and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) cell signaling transduction pathways. Here, we assessed the effects of protectin D1 (PD1) on imiquimod (IMQ)-induced psoriasiform skin inflammation and keratinocytes. PD1 showed clinical improvement in skin thickness, redness, and scaling in psoriasis mouse models. Moreover, PD1 decreased IL-1β, IL-6, IL-17, and CXCL1 mRNA expressions and reduced STAT1 and NF-κB signaling pathway activation in lesions. Serum myeloperoxidase, IgG2a, IL-1β, IL-6, IL-17, and TNF-α and spleen CD4⁺IFN-γ⁺IL-17⁺ T lymphocytes were reduced after PD1 treatment in IMQ-induced psoriasiform mouse models. In addition, IL-1β, IL-6, IL-8, and IL-18BP gene expressions were decreased in PD1-treated keratinocytes. Moreover, a decrease in the expression levels of CCL17 and IL-6 and an inhibition of the STAT1 and NF-κB signaling transduction pathways was observed in keratinocytes. These PD1 anti-inflammatory effects suggest that it is a good therapeutic candidate for psoriasis.

Biotechnologically Produced Lavandula angustifolia Mill. Extract Rich in Rosmarinic Acid Resolves Psoriasis-Related Inflammation Through Janus Kinase/Signal Transducer and Activator of Transcription Signaling

Psoriasis is a common skin pathology, characterized by dysregulation of epidermal keratinocyte function attended by persistent inflammation, suggesting that molecules with anti-inflammatory potential may be effective for its management. Rosmarinic acid (RA) is a natural bioactive molecule known to have an anti-inflammatory potential. Here we examined the effect of biotechnologically produced cell suspension extract of Lavandula angustifolia Mill (LV) high in RA content as treatment for psoriasis-associated inflammation in human keratinocytes. Regulatory genes from the nuclear factor kappa B (NF-κB) and Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways were upregulated upon stimulation with a combination of interferon gamma (IFN-γ), interleukin (IL)-17A and IL-22. We also observed that both LV extract and RA could inhibit JAK2, leading to reduced STAT1 phosphorylation. Further, we demonstrated that LV extract inhibited phosphoinositide 3-kinases (PI3K) and protein kinase B (AKT), which could be implicated in reduced hyperproliferation in keratinocytes. Collectively, these findings indicate that the biotechnologically produced LV extract resolved psoriasis-like inflammation in human keratinocytes by interfering the JAK2/STAT1 signaling pathway and its effectiveness is due to its high content of RA (10%). Hence, both LV extract and pure RA possess the potential to be incorporated in formulations for topical application as therapeutic approach against psoriasis.

Selenium nanoparticles produce a beneficial effect in psoriasis by reducing epidermal hyperproliferation and inflammation

Background

Psoriasis is a chronic autoimmune skin disease characterized by hyperproliferation of keratinocytes. Wide treatment options used to treat psoriasis is associated with various adverse effects. To overcome this nanoformulation is prepared. Selenium is an essential trace element and plays major role in oxidation reduction system. Toxicity and stability limits the applications of selenium. Toxicity can be reduced and stabilized upon preparation into nanoparticles.

Results

Selenium nanoparticles (SeNPs) exhibit potent apoptosis through the generation of reactive oxygen species (ROS) with cell cycle arrest. SeNPs topical gel application produced significant attenuation of psoriatic severity with the abrogation of acanthosis and splenomegaly. SeNPs reduced the phosphorylation and expressions of MAPKs, STAT3, GSK-3β, Akt along with PCNA, Ki67, and cyclin-D1.

Conclusion

SeNPs inhibit various inflammation and proliferation mediated pathways and could be an ideal candidate for psoriasis therapy.

Materials and methods

SeNPs were characterized and various techniques were used to determine apoptosis and other molecular mechanisms. In vivo studies were performed by inducing psoriasis with imiquimod (IMQ). SeNPs were administered via topical route.

Graphic Abstract

Preparation and In Vivo Evaluation of Rosmarinic Acid-Loaded Transethosomes After Percutaneous Application on a Psoriasis Animal Model

The topical use of rosmarinic acid (RA) in skin inflammatory pathologies is restricted due to its poor water solubility, poor permeability, and chemical instability. In this study, RA-loaded transethosomes-in-Carbopol® formulations have been developed to evaluate its anti-inflammatory activity on imiquimod-induced psoriasis-like skin inflammation in mice. In vitro release profiles demonstrated sustained behavior due to the retentive action of gel and the entrapment of RA into the vesicles. However, the low viscosity of the combined formulation increased the drug release rate. Animal evaluation of anti-inflammatory activity demonstrated that transethosomes-in-gel containing dexamethasone (Dex-TE-Gel), as positive control, showed effect in all the pro-inflammatory parameters evaluated, evidencing that these drug-loaded nanocarriers have been effectively reached the site of action. In addition, transethosomes-in-gel containing RA (RA-TE-Gel) formulations produced a great reduction in the punch edema (P < 0.001) and in TNF-α and IL-6 (P < 0.05). However, non-significant differences were obtained for IL-1β, IL17, and MPO. Despite the protecting effect of Carbopol® and transethosomes on oxidation index and antioxidant activity of RA over the 7 days of treatment, however, a degradation process of this antioxidant to caffeic acid may be the cause of these in vivo results. We have also checked that the pH existing into the intercellular space of damaged cells (pH 6.8) may be affecting. Therefore, our results suggest that RA-TE-Gel could act as an effective RA formulation for skin delivery; further studies will help to understand the loss of activity at the cellular level.

Isolation, identification, and HPTLC quantification of dehydrodeoxycholic acid from Persian Gulf sponges

This study aims to investigate the chemical constituents of sponges Dysidea avara (D. avara) and Axinella sinoxea (A. sinoxea), grown up in the Persian Gulf, as well as dehydrodeoxycholic acid (DHCA) content in methanolic extracts of the selected sponges. The chromatography-mass spectrometry (GC-MS) fingerprint of bioactive compounds from methanolic extracts of the selected marine sponge samples was investigated. Based on molecular docking results, among chemical compounds found in marine sponges, DHCA has anti-inflammatory and antipsoriatic properties. They also indicated that DHCA generated stable complexes with 1w81, 3bqm, and 3k8o receptors (psoriasis-related targets) with a binding energy (BE) of -9.26, -10.62, and -7.59 kcal mol^-1, respectively. DHCA is isolated from the methanolic extracts of marine sponge samples on chromatographic plates was quantified after derivatization with anisaldehyde reagent by the validated HPTLC method. In-situ HPTLC-DPPH was also calculated to evaluate the free radical-scavenging activity (FRSA) of DHCA. In-silico ADME (Absorption, Distribution, Metabolism, Excretion) predictions revealed that the compound had minimum toxicity and acceptable human intestinal absorption (HIA), as well as low skin permeability. These can potentially be employed as lead compounds to develop a novel antipsoriatic drug.

DGT, a novel heterocyclic diterpenoid, effectively suppresses psoriasis via inhibition of STAT3 phosphorylation

BACKGROUND AND PURPOSE

Psoriasis is a chronic immune-mediated inflammatory skin disease that easily recurs and is difficult to cure. DGT is a novel synthetic heterocyclic diterpenoid, whose structure has not been previously reported. We have investigated the action of DGT against psoriasis, specifically the hyperproliferation of epidermal keratinocytes, angiogenesis and pathogenic inflammatory responses.

EXPERIMENTAL APPROACH

We investigated its pharmacokinetics in skin after topical administration. We characterized its pharmacological actions in vitro and in vivo using cell proliferation assay, cell apoptosis assay, diethylstilbestrol-induced mouse vaginal epithelial cell mitosis model, tube formation assay, cell migration assay, chick embryonic chorioallantoic membrane (CAM) assay, histological, flow cytometric analysis and imiquimod (IMQ)-induced psoriasis-like model.

KEY RESULTS

DGT was found to be mainly distributed in the epidermis and dermis, which indicated that DGT was suitable as a topical treatment. DGT inhibited cell proliferation and induced apoptotic cell death of keratinocytes in vitro and in vivo. Moreover, DGT inhibited endothelial cell proliferation, tube formation and migration of in vitro angiogenesis, as well as in vivo CAM angiogenesis. In an IMQ-induced psoriasis-like skin inflammation murine model, topical application of DGT ameliorated keratinocyte proliferation and inflammatory response, especially in IL-17-related psoriasiform dermatitis. Furthermore, our results demonstrated that DGT prevented these pathological processes of psoriasis through suppression of STAT3 phosphorylation.

CONCLUSION AND IMPLICATIONS

DGT has great potential as a novel therapeutic agent for the treatment of psoriatic skin disease.

Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

BACKGROUND

Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms.

METHODS

HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR.

RESULTS

Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice.

CONCLUSIONS

Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

Chrysoeriol ameliorates TPA-induced acute skin inflammation in mice and inhibits NF-κB and STAT3 pathways

BACKGROUND

Chrysoeriol is a flavone found in diverse dietary and medicinal herbs such as Lonicerae Japonicae Flos (the dried flower bud or newly bloomed flower of Lonicera japonica Thunb.). These herbs are commonly used for treating inflammatory diseases. Herbal extracts containing chrysoeriol have been shown to have anti-inflammatory effects and inhibit nuclear factor-kappa B (NF-κB) signaling. Some of these extracts can inhibit signal transducers and activators of transcription 3 (STAT3) signaling in cancer cells.

PURPOSE

This study aimed to determine whether chrysoeriol has anti-inflammatory effects and whether NF-κB and STAT3 pathways are involved in the effects.

STUDY DESIGN AND METHODS

A TPA (12-O-tetradecanoylphorbol-13-acetate)-induced ear edema mouse model and LPS-stimulated RAW264.7 cells were used to evaluate the effects of chrysoeriol. Griess reagent was used to measure the production of nitric oxide (NO). Western blot and enzyme-linked immunosorbent assays were employed to detect protein levels. RT-qPCR analyses were used to detect mRNA levels. Haematoxylin and eosin (H&E) staining was employed to examine the pathological conditions in animal tissues.

RESULTS

In the mouse model, chrysoeriol ameliorated acute skin inflammation, evidenced by reduced ear thickness, ear weight and number of inflammatory cells in inflamed ear tissues. The compound lowered protein levels of phospho-p65 (Ser536), phospho-STAT3 (Tyr705), inducible nitric oxide synthases (iNOS), cyclooxygenase-2 (COX-2), interleukin 6 (IL-6), IL-1β and tumor necrosis factor α (TNF-α) in mouse swollen ears. In LPS-stimulated RAW264.7 cells, chrysoeriol also lowered levels of these proteins. In addition, chrysoeriol decreased the production of NO and prostaglandin E2; inhibited the phosphorylation of inhibitor of κB (Ser32), p65 (Ser536) and Janus kinase 2 (Tyr1007/1008); decreased nuclear localization of p50, p65 and STAT3; and down-regulated mRNA levels of pro-inflammatory cytokines IL-6, IL-1β and TNF-α that are transcriptionally regulated by NF-κB and STAT3 in the cell model.

CONCLUSION

We for the first time demonstrated that chrysoeriol ameliorates TPA-induced ear edema in mice, and that inhibition of JAK2/STAT3 and IκB/p65 NF-κB pathways are involved in the anti-inflammatory effects of chrysoeriol. This study provides chemical and pharmacological justifications for the use of chrysoeriol-containing herbs in treating inflammatory diseases, and provides pharmacological groundwork for developing chrysoeriol as a novel anti-inflammatory agent.

Convallatoxin induces HaCaT cell necroptosis and ameliorates skin lesions in psoriasis-like mouse models

Psoriasis is considered an immune-mediated inflammatory skin disorder that affects the quality of life of nearly four percent of the world population. Considering the side effects of existing therapeutic drugs and the urgent need for new drug development, we screened more than 250 traditional Chinese medicine compounds to identify drugs that significantly reduced the viability of human HaCaT keratinocytes, a psoriasis-related model cell line. Convallatoxin (CNT) was found to be a highly effective inhibitor of HaCaT cell viability. Subsequent mechanistic studies revealed that CNT induced HaCaT cell death by necroptosis rather than by apoptosis. CNT destroyed the membrane integrity of HaCaT cells, as detected by nuclear propidium iodide (PI) staining and lactate dehydrogenase (LDH) release. Additionally, the intercellular levels of adenosine triphosphate (ATP) were lower in HaCaT cells treated with CNT than in control HaCaT cells, and typical necroptosis-associated characteristics were observed by electron microscopy in cells treated with CNT. Furthermore, compared with control HaCaT cells, CNT-treated HaCaT cells produced more reactive oxygen species (ROS), but this effect was inhibited by the antioxidants N-acetyl-cysteine (NAC), diphenyleneiodonium chloride (DPI), and apocynin and the necroptosis inhibitor Nec-1. In addition, antioxidant treatment attenuated necroptotic cell death, suggesting that CNT-induced HaCaT necroptosis is mediated by oxidative stress. More importantly, CNT ameliorated skin lesions and inflammation in imiquimod (IMQ)- and 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced psoriasis-like mouse models. In conclusion, our results demonstrate that CNT is cytotoxic against HaCaT cells in vitro and exerts antipsoriatic activities in two mouse models of psoriasis in vivo, making CNT a potential promising candidate drug for future research.

Nitidine chloride induces S phase cell cycle arrest and mitochondria-dependent apoptosis in HaCaT cells and ameliorates skin lesions in psoriasis-like mouse models

Psoriasis is a common dermatosis causing considerable inconvenience to 4% of the general population. Traditional psoriasis treatments often cause side effects, drug resistance and complications, necessitating development of safer and more effective treatments. In this study, we screened over 600 natural compounds to identify viability inhibitors of human HaCaT keratinocytes cultured in vitro. The results showed that nitidine chloride was a highly effective inhibitor. Further studies revealed that nitidine chloride inhibited HaCaT proliferation and induced S phase cell cycle arrest; these effects were associated with reduced DNA synthesis, decreased Ki67, cyclin A, and cyclin D1 levels, and increased p53 protein expression. Nitidine chloride also significantly downregulated bcl-2 and upregulated bax, cleaved caspase-9 and cleaved caspase-3. Mechanistic studies revealed that nitidine chloride-induced apoptosis involved the c-Jun N-terminal kinase (JNK) pathway. More importantly, in 12-O-tetradecanoyl-phorbol-13-acetate (TPA)- and imiquimod (IMQ)-induced epidermal hyperplasia and inflammation models, nitidine chloride inhibited topical edema in mouse ear and back skin, substantially reducing tissue thickness and weight. In some cases, nitidine chloride also ameliorated conditions caused by TPA and IMQ, such as angiogenesis and infiltration of large numbers of inflammatory cells around blood vessels. Additionally, nitidine chloride inhibited the expression of various proinflammatory cytokines in the two animal models. In conclusion, our results are the first to demonstrate that nitidine chloride inhibits the proliferation of HaCaT cells, induces apoptosis partly via the JNK signaling pathway in vitro and ameliorates skin lesions and inflammation in vivo, making it an appropriate candidate for psoriasis treatment.

Therapeutic drug monitoring of biologics in psoriasis

Biologics are an important component of the armamentarium of drugs in the treatment of moderate to severe psoriasis. There is increasing evidence that therapeutic drug monitoring (TDM) encompassing the measurement of trough concentrations and anti-drug antibodies (ADA), together with clinical response is emerging as a valuable tool for clinical decision making. It aids in targeted dose adjustments in patients with low drug concentrations, monitoring of adherence and assessment of patients who lose response to biologics or do not respond at all. The high prevalence of psoriasis, its impact on patients' lives and costs spent on therapy motivate an evidence-based and cost-effective utility of biologics. We performed a literature review on the TDM of TNF alpha antagonists (adalimumab, infliximab, etanercept), IL12/23 antagonists (ustekinumab, guselkumab, tildrakizumab), IL17A inhibitors (secukinumab, ixekizumab) and biosimilars used in the treatment of psoriasis. Although establishing target therapeutic ranges for biologics is ideal, this has only been explored in adalimumab. We also propose a treatment algorithm for the practical application of TDM depending on drug trough concentrations, presence/absence of anti-drug antibodies and clinical response of patients. The practice of TDM is recommended in routine clinical practice where possible.

Inhibition of microRNA-495 suppresses chondrocyte apoptosis through activation of the NF-κB signaling pathway by regulating CCL4 in osteoarthritis

As a common form of arthritis, osteoarthritis (OA) represents a degenerative disease, characterized by articular cartilage damage and synovium inflammation. Recently, the role of various microRNAs (miRs) and their specific expression in OA has been highlighted. Therefore, the aim of the current study was to elucidate the role by which miR-495 and chemokine ligand 4 (CCL4) influence the development and progression of OA. OA mice models were established, after which the CCL4 and collagen levels as well as cell apoptosis were determined in cartilage tissue of OA mice. The chondrocytes of the OA mice models were subsequently treated with a series of miR-495 mimic, inhibitor, and siRNA against CCL4. Afterwards, miR-495 expressions as well as the levels of CCL4, p50, p65, and IkBa and the extent of IkBa phosphorylation in addition to the luciferase activity of NF-kB were measured accordingly. Finally, cell apoptosis and cell cycle distribution were detected. miR-495 was highly expressed while NF-κB, CCL4, and collagen II were poorly expressed. Cell apoptosis was elevated in the cartilage tissue of the OA mice. CCL4 was a potential target gene of miR-495. Downregulation of miR-495 led to accelerated chondrocyte proliferation accompanied by diminished cell apoptosis among the OA mice. Taken together, the results of the current study demonstrated that inhibition of miR-495 suppressed chondrocyte apoptosis and promoted its proliferation through activation of the NF-κB signaling pathway by up-regulation of CCL4 in OA.

Infiltration of T Cells into a Three-Dimensional Psoriatic Skin Model Mimics Pathological Key Features

Psoriasis is an autoimmune chronic dermatosis that is T cell-mediated, characterized by epidermal thickening, aberrant epidermal differentiation and inflammatory infiltrates, with a dominant Th1 and Th17 profile. Additional in vitro models are required to study the complex interactions between activated T cells and skin cells, and to develop new, more effective treatments. We have therefore sought to model this psoriatic inflammation by the generation of tissue-engineered immunocompetent tissues, and we have investigated the response of activated T-cell infiltration in models produced with lesional psoriatic skin cells on major hallmarks of psoriasis. The immunocompetent lesional skin model displayed a delayed onset of epidermal differentiation, an hyperproliferation of the basal keratinocytes, a drastic increase in the secretion of proinflammatory cytokines, and a disturbed expression of key transcription factors, as observed in lesional plaques, suggesting a crucial importance of combining the pathological phenotype of cutaneous cells to T cells in order to generate a relevant model for psoriasis. Finally, we found this skin model to be responsive to methotrexate treatment, making it a valuable tool for drug development.

Protective effects of ambroxol in psoriasis like skin inflammation: Exploration of possible mechanisms

The purpose of this study was to investigate the protective effects of ambroxol in psoriasis-like skin inflammation both in vitro and in vivo and delineate the molecular mechanism of ambroxol. Our data demonstrated that ambroxol has an imperative role in inhibiting the lipopolysaccharide (LPS) stimulated nitrite levels, total cellular and mitochondrial reactive oxygen species level which was determined by Griess assay, DCFDA, and MitoSOX Red staining, respectively. We found that ambroxol remarkably reduced imiquimod (IMQ) induced epidermal hyperplasia, psoriasis area and severity index (PASI) scoring, splenomegaly, skin, and ear fold thickness. In addition, the histopathological evaluation revealed that ambroxol topical and subcutaneous treatment eloquently reduced psoriasiform lesions including acanthosis. Moreover, with ambroxol intervention, the levels of antioxidants glutathione (GSH), superoxide dismutase (SOD), and IL-10 were found to be increased along with a reduction in nitrite levels in skin tissues. On the other hand, ambroxol treatment significantly reduced imiquimod-induced levels of inflammatory cytokines such as IL-1β, IL-6, IL-17, IL-22, IL-23, TGF-β, and TNF-α. Furthermore, from immunoblotting, we found a decrease in the protein expression of nitrotyrosine, iNOS, NF-κB and MAPKs signaling cascade with a concomitant increase in the expression of Nrf-2 and SOD-1 in RAW 264.7 cells and skin tissues by ambroxol. Similar findings were observed by immunofluorescence in macrophages. Moreover, ambroxol downregulated the ICAM-1 and Ki67 expression observed in skin tissues. Collectively, our results demonstrate that ambroxol may have intriguing therapeutic possibilities in attenuating psoriasis.

Genistein suppresses psoriasis-related inflammation through a STAT3-NF-κB-dependent mechanism in keratinocytes

Psoriasis is a chronic recurrent skin inflammatory disease, and inhibition of inflammation may be an effective means of treating psoriasis. The flavonoid genistein has a clear anti-inflammatory effect. However, the anti-psoriatic effects of genistein and their underlying mechanisms remain unclear. In this study, we investigated the effects of genistein on imiquimod (IMQ)-induced psoriasis-like skin lesions in vivo and explored the mechanisms underlying those effects in vitro. It was found that genistein can significantly improve IMQ-induced pathological scores of cutaneous skin lesions in mice, reduce epidermal thickness, and inhibit the expression of inflammatory factors，including interleukin (IL)-1β, IL-6, tumour necrosis factor-alpha (TNF-α), chemokine ligand 2 (CCL2), IL-17 and IL-23. In vitro studies, genistein inhibited the proliferation of human keratinocyte HaCaT cells and inhibited the expression of inflammatory factors in a dose-dependent manner which induced by TNFα. Further researches showed that genistein could also significantly inhibit phosphorylated STAT3 (pSAT3) expression in IMQ mice dorsal skin and in TNF-α-induced HaCaT cells. The inhibitory effect of genistein on the expression of IL-6, IL-23 and TNF-α was weakened after Stat3 siRNA in HaCaT cells. Genistein could also significantly inhibit TNF-α induced the nuclear translocation of NF-κB, and inhibit the phosphorylation of I-kBα (pI-kBα). After combining with NF-κB blocker BAY 11-7082, the effect of genistein down-regulate the expression of TNF-α and VEGFA was attenuated in HaCaT cells. The results suggest that genistein may be developed for the treatment of psoriasis lesions.

Effect of RNA Interference Targeting STAT3 Gene Combined with Ultrasonic Irradiation and SonoVue Microbubbles on Proliferation and Apoptosis in Keratinocytes of Psoriatic Lesions

Background

Signal transducer and activator of transcription 3 (STAT3) was strongly expressed and activated in psoriatic keratinocytes (KCs) and correlated with the severity of psoriasis. The study aimed to investigate the effects of STAT3 small interfering RNA (siRNA) combined with ultrasonic irradiation and SonoVue microbubbles on the proliferation and apoptosis in KCs of psoriatic lesions and the relative mechanisms.

Methods

Psoriatic KCs were transfected under four experimental conditions: (1) STAT3 siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (LUS group); (2) STAT3 siRNA only carried by Lipofectamine 3000 (L group); (3) the negative control of siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (siRNA-NC); (4) not treated as Blank. Cell Counting Kit-8 assay was used to evaluate the cell proliferation. Cell cycle analysis was detected with cycle test Plus DNA reagent kit associated with flow cytometer. FITC Annexin V apoptosis detection kit associated with flow cytometer was applied for apoptosis analysis. Fluo calcium indicator associated with flow cytometer was used to analyze intracellular free calcium concentration ([Ca²⁺]_i). The expressions of cyclin D1 and Bcl-xL were detected both at the mRNA level by real-time reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level by Western blotting. The obtained data were statistically evaluated by two-way analysis of variance.

Results

STAT3 siRNA inhibited the growth of KCs in a time-dependent manner showing the highest proliferation inhibition in LUS group with proliferation ratio of 45.38% ± 5.85% at 72h (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced an altered cell cycle distribution of KCs showing the highest increases in G2/M-phase population up to 18.06% ± 0.36% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced late apoptosis of KCs with the highest late apoptosis percentage of 22.87% ± 1.28% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the elevation of [Ca²⁺]_iof KCs with the highest calcium fluorescence intensity mean of 1213.67 ± 60.51 in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the downregulation of cyclin D1 and Bcl-xL expressions of KCs at mRNA and protein levels with the lowest expressions in LUS group with cyclin D1 expression of 51.81% ± 9.58% and 70.17% ± 4.22% at mRNA level and at protein level, respectively, and with Bcl-xL expression of 37.58% ± 4.92% and 64.06% ± 7.78% at mRNA level and at protein level, respectively (P < 0.05 vs. L group, siRNA-NC, or Blank).

Conclusions

STAT3 siRNA inhibited the growth and induced the apoptosis in psoriatic KCs likely partly through altering cell cycle distribution, elevating [Ca²⁺]_i, and downregulating cyclin D1 and Bcl-xL expressions. Silencing the target gene STAT3 in psoriatic KCs with siRNA combined with ultrasonic irradiation and microbubbles would contribute to a significant innovation as a new clinical therapy for psoriasis.

Therapeutic effects of bee venom and its major component, melittin, on atopic dermatitis in vivo and in vitro

BACKGROUND AND PURPOSE

Atopic dermatitis (AD) is a multifactorial skin condition with complex interactions of innate and adaptive immune responses. There are several existing therapies for AD, including topical glucocorticosteroids, emollients, phototherapies, calcineurin inhibitors and immunosuppressants, such as cyclosporine A. Although these therapies reduce inflammation, they also cause serious side effects. Therefore, it is necessary to develop new therapeutic approaches for AD treatment without side effects. There are several studies on natural materials or toxins, such as herbs, ginseng extract and snake venom, for AD treatment. However, treatment of AD with bee venom and its major component, melittin has rarely been studied.

EXPERIMENTAL APPROACH

Effects of bee venom and melittin were studied in a model of AD in vivo induced by 1-chloro-2,4-dinitrobenzene (DNCB) in female Balb/c mice and in cultures of human keratinocytes, stimulated by TNF-α/IFN-γ. The potential pharmacological effects of bee venom and melittin on these in vivo and in vitro AD-like skin disease models were studied.

KEY RESULTS

Bee venom and melittin exhibited potent anti-atopic activities, shown by decreased AD-like skin lesions, induced by DNCB in mice. In vitro studies using TNF-α/IFN-γ-stimulated human keratinocytes showed that bee venom and melittin inhibited the increased expression of chemokines, such as CCL17 and CCL22, and pro-inflammatory cytokines, including IL-1β, IL-6 and IFN-γ, through the blockade of the NF-κB and STAT signalling pathways.

CONCLUSIONS AND IMPLICATIONS

Our results suggest that bee venom and melittin would be suitable for epicutaneous application, as topical administration is often appropriate for the treatment of AD.

Chemerin/ChemR23 axis triggers an inflammatory response in keratinocytes through ROS-sirt1-NF-κB signaling

Psoriasis is a chronic disease which carries the emotional and social burden, promotes joint disability and raises comorbidity possibility in patients. Obesity is closely correlated with the occurrence of psoriasis and adipokines produced by adipose tissues were found to be critical culprits. Chemerin is one of them and its expression was increased in patients with psoriatic arthritis. In our hypothesis, chemerin might act on keratinocytes and promote an inflammatory response, which plays an essential role in psoriatic epidermis. To validate our hypothesis, HaCaT cells and primary human keratinocytes were treated with chemerin (5, 10, and 20 ng/mL for 24 hours). Enzyme-linked immunosorbent assay (ELISA) was used to determine the secretion of inflammatory factors. Nuclear factor-κB (NF-κB) activation and p65 acetylation were evaluated by Western blot analysis. The expression and activity of sirtuin 1 (sirt1), a deacetylase act on p65, were also analyzed. The results showed that chemerin prompted inflammatory factors secretion, NF-κB activation and p65 acetylation through chemerin receptor 23 receptor. Chemerin constrained the expression and deacetylase activity of sirt1 through augment of reactive oxygen species (ROS) production. Additionally, chemerin exacerbated psoriasiform dermatitis in imiquimod-treated mice model. In conclusion, chemerin can seduce inflammatory response and promote NF-κB activation through inhibition of sirt1 activity by ROS production.

Fucoxanthin-Containing Cream Prevents Epidermal Hyperplasia and UVB-Induced Skin Erythema in Mice

Microalgae represent a source of bio-active compounds such as carotenoids with potent anti-inflammatory and antioxidant properties. We aimed to investigate the effects of fucoxanthin (FX) in both in vitro and in vivo skin models. Firstly, its anti-inflammatory activity was evaluated in LPS-stimulated THP-1 macrophages and TNF-α-stimulated HaCaT keratinocytes, and its antioxidant activity in UVB-irradiated HaCaT cells. Next, in vitro and ex vivo permeation studies were developed to determine the most suitable formulation for in vivo FX topical application. Then, we evaluated the effects of a FX-containing cream on TPA-induced epidermal hyperplasia in mice, as well as on UVB-induced acute erythema in hairless mice. Our results confirmed the in vitro reduction of TNF-α, IL-6, ROS and LDH production. Since the permeation results showed that cream was the most favourable vehicle, FX-cream was elaborated. This formulation effectively ameliorated TPA-induced hyperplasia, by reducing skin edema, epidermal thickness, MPO activity and COX-2 expression. Moreover, FX-cream reduced UVB-induced erythema through down-regulation of COX-2 and iNOS as well as up-regulation of HO-1 protein via Nrf-2 pathway. In conclusion, FX, administered in a topical formulation, could be a novel natural adjuvant for preventing exacerbations associated with skin inflammatory pathologies as well as protecting skin against UV radiation.

IκBζ is a key transcriptional regulator of IL-36-driven psoriasis-related gene expression in keratinocytes

Psoriasis is an autoinflammatory disease characterized by cytokine-driven keratinocyte proliferation and infiltration of immune cells. While IL-17A and TNFα are established targets in psoriasis therapy, IL-36 is emerging as an important cytokine in this disease. The mechanisms of IL-36–driven proinflammatory responses are largely unknown. Here we identified IκBζ, a transcriptional regulator of selective NF-κB target genes, as a crucial mediator of IL-36 action. In keratinocytes, IκBζ was required for the expression of several psoriasis-related cytokines and chemokines. Moreover, genetic deletion of IκBζ prevented IL-36–mediated dermatitis induction in mice. Since IκBζ is essential not only for IL-36 but also for IL-17 signaling, our results suggest that inhibition of IκBζ function could be a future strategy in psoriasis therapy.

Proinflammatory cytokine signaling in keratinocytes plays a crucial role in the pathogenesis of psoriasis, a skin disease characterized by hyperproliferation and abnormal differentiation of keratinocytes and infiltration of inflammatory cells. Although IL-17A and TNFα are effective therapeutic targets in psoriasis, IL-36 has recently emerged as a proinflammatory cytokine. However, little is known about IL-36 signaling and its downstream transcriptional responses. Here, we found that exposure of keratinocytes to IL-36 induced the expression of IκBζ, an atypical IκB member and a specific transcriptional regulator of selective NF-κB target genes. Induction of IκBζ by IL-36 was mediated by NF-κB and STAT3. In agreement, IL-36–mediated induction of IκBζ was found to be required for the expression of various psoriasis-related genes involved in inflammatory signaling, neutrophil chemotaxis, and leukocyte activation. Importantly, IκBζ-knockout mice were protected against IL-36–mediated dermatitis, accompanied by reduced proinflammatory gene expression, decreased immune cell infiltration, and a lack of keratinocyte hyperproliferation. Moreover, expression of IκBζ mRNA was highly up-regulated in biopsies of psoriasis patients where it coincided with IL36G levels. Thus our results uncover an important role for IκBζ in IL-36 signaling and validate IκBζ as an attractive target for psoriasis therapy.

Decreased expression of G-protein-coupled receptors GPR43 and GPR109a in psoriatic skin can be restored by topical application of sodium butyrate

The G-protein-coupled receptors GPR43 and GPR109a are known to play an important role in mediating anti-inflammatory and anti-cancer functions in the gut. Short-chain fatty acids, such as sodium butyrate (SB), are activators of GPR43 and GPR109a and thereby promote anti-inflammatory effects. The present study aimed to examine the expression of these receptors and their reaction to SB in psoriasis. Lesional and non-lesional biopsies of 6 psoriasis patients and of 4 controls were obtained and stained for GPR109a and GPR43. Ex vivo stimulation with SB was performed on fresh biopsy material. Lesional and non-lesional psoriatic skin showed a decreased expression of GPR109a and GPR43 on keratinocytes in comparison with control skin. Topical application of SB was able to increase the low-level expression of both receptors. The data suggest that SB by restoring the impaired expression of GPR109a and GPR43 might exert anti-inflammatory effects and may be utilized as a topical tool for the treatment of psoriasis, which has to be proven in future clinical trials.

Esculetin Ameliorates Psoriasis-Like Skin Disease in Mice by Inducing CD4+Foxp3+ Regulatory T Cells

Psoriasis is an autoimmune and inflammatory skin disease affecting around 2-3% of the world's population. Patients with psoriasis need extensive treatments with global immunosuppressive agents that may cause severe side effects. Esculetin, a type of coumarins, is an active ingredient extracted mainly from the bark of Fraxinus rhynchophylla, which has been used to treat inflammatory and autoimmune diseases in China. However, the antipsoriatic effects of esculetin have not been reported. In this study, we aimed to investigate the effects of esculetin on psoriatic skin inflammation in a mouse model and explored the potential molecular mechanisms underlying its action. We found that esculetin ameliorated the skin lesion and reduced PASI scores as well as weight loss in imiquimod-induced psoriasis-like mice, accompanied with weakened proliferation and differentiation of keratinocytes and T cell infiltration in esculetin-treated psoriatic mice. In addition, esculetin reduced the frequency of CD8⁺CD44^highCD62L^low effector T cells in psoriatic mice. In contrast, it increased the frequency of CD4⁺Foxp3⁺ Tregs in both lymph nodes and spleens of the psoriatic mice while promoting the differentiation of CD4⁺CD25^- T cells into CD4⁺Foxp3⁺ Tregs in vitro. Interestingly, depleting CD4⁺Foxp3⁺ Tregs largely reversed esculetin-mediated reduction in PASI scores, indicating that esculetin attenuates murine psoriasis mainly by inducing CD4⁺Foxp3⁺ Tregs. Furthermore, the mRNA levels of proinflammatory cytokines in the psoriatic mouse skin, including IL-6, IL-17A, IL-22, IL-23, TNF-α, and IFN-γ, were dramatically decreased by the treatment with esculetin. Finally, we found that esculetin inhibited the phosphorylation of IKKα and P65 in the psoriatic skin, suggesting that it inhibits the activation of NF-κB signaling. Thus, we have demonstrated that esculetin attenuates psoriasis-like skin lesion in mice and may be a potential therapeutic candidate for the treatment of psoriasis in clinic.

Dang-Gui-Liu-Huang Tang a traditional herbal formula, ameliorates imiquimod-induced psoriasis-like skin inflammation in mice by inhibiting IL-22 production

BACKGROUND

The traditional herbal formula, Dang-Gui-Liu-Huang Tang (DGLHT) has been previously shown to inhibit T lymphocyte proliferation and suppress dendritic cell function. Hypothesis/Purpose: To assess the therapeutic value of DGLHT for the treatment of psoriasis, a Th1 and/or Th17 cell-mediated inflammatory skin disease, and to investigate the underlying molecular mechanisms.

METHODS

An in vivo mouse model of imiquimod (IMQ)-induced psoriasis-like inflammation was used to investigate the effect of DGLHT. The anti-inflammatory effects of an ethanolic extract of DGLHT (DGLHT-E) and the mechanism responsible were examined in an in vitro model using IL-1α, IL-17A, IL-22, oncostatin M, plus TNF-α (M5) stimulated HaCaT cells. The anti-proliferative effect of DGLHT-E was examined by analyzing the expression levels of K16, K17 and Ki67 in IL-22 stimulated HaCaT cells.

RESULTS

Topical application of 1% DGLHT-E significantly reduced psoriasis-like symptoms including scaling and epidermal hyperplasia in IMQ-treated mice. Immunohistochemical studies showed that DGLHT-E exerted potent anti-inflammatory effects by inhibiting IL-22 production in local skin lesions. DGLHT-E also attenuated the productions of CXCL10 and CCL20 in M5-stimulated HaCaT cells by suppressing the ERK1/2, JNK and STAT3 signaling pathways. Furthermore, berberine hydrochloride, a primary constituent of DGLHT-E inhibited the expressions of the proliferation markers K16 and K17 in IL-22 stimulated HaCaT cells.

CONCLUSION

These results suggested that DGLHT-E offers a possible treatment for psoriasis, and that berberine hydrochloride might be a useful component of ointment-based treatments for psoriatic lesions.

Topical Application of Glycolipids from Isochrysis galbana Prevents Epidermal Hyperplasia in Mice

Chronic inflammatory skin diseases such as psoriasis have a significant impact on society. Currently, the major topical treatments have many side effects, making their continued use in patients difficult. Microalgae have emerged as a source of bio-active molecules such as glycolipids with potent anti-inflammatory properties. We aimed to investigate the effects of a glycolipid (MGMG-A) and a glycolipid fraction (MGDG) obtained from the microalga Isochrysis galbana on a TPA-induced epidermal hyperplasia murine model. In a first set of experiments, we examined the preventive effects of MGMG-A and MGDG dissolved in acetone on TPA-induced hyperplasia model in mice. In a second step, we performed an in vivo permeability study by using rhodamine-containing cream, ointment, or gel to determinate the formulation that preserves the skin architecture and reaches deeper. The selected formulation was assayed to ensure the stability and enhanced permeation properties of the samples in an ex vivo experiment. Finally, MGDG-containing cream was assessed in the hyperplasia murine model. The results showed that pre-treatment with acetone-dissolved glycolipids reduced skin edema, epidermal thickness, and pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6, IL-17) in epidermal tissue. The in vivo and ex vivo permeation studies showed that the cream formulation had the best permeability profile. In the same way, MGDG-cream formulation showed better permeation than acetone-dissolved preparation. MGDG-cream application attenuated TPA-induced skin edema, improved histopathological features, and showed a reduction of the inflammatory cell infiltrate. In addition, this formulation inhibited epidermal expression of COX-2 in a similar way to dexamethasone. Our results suggest that an MGDG-containing cream could be an emerging therapeutic strategy for the treatment of inflammatory skin pathologies such as psoriasis.

The Immunogenetics of Psoriasis and Implications for Drug Repositioning

Psoriasis is a genetically-regulated, T lymphocyte-mediated autoimmune skin disease that causes systemic damage, seriously affecting patient quality of life and survival. Psoriasis treatments, which aim to control the disease’s development, are greatly limited because its etiology and pathogenesis have not yet been fully elucidated. A large number of studies have demonstrated that immunogenetic elements are the most important factors responsible for psoriasis susceptibility. This paper delineates the immunogenetic mechanisms of psoriasis and provides useful information with regards to performing drug repositioning for the treatment of psoriasis.

Resolvin D1 attenuates imiquimod-induced mice psoriasiform dermatitis through MAPKs and NF-κB pathways

BACKGROUND

Resolvin D1 (RvD1), a pro-resolution lipid mediator derived from docosahexaenoic acid (DHA), has been described to promote several kinds of inflammatory resolution. However, the effects and anti-inflammatory mechanisms of RvD1 on psoriasis have not been previously reported.

OBJECTIVE

The present study aimed to determine the protective effects and the underlying mechanisms of RvD1 on imiquimod (IMQ)-induced psoriasiform dermatitis.

METHODS

Mice were topically treated with IMQ to develop psoriasiform dermatitis on their shaved back, pretreated intraperitoneally (i.p.) with or without RvD1 or tert-butoxycarbonyl Met-Leu-Phe peptide (Boc), a lipoxin A4 (ALX) receptor antagonist. The severity was monitored and graded using a modified human scoring system, the Psoriasis Area and Severity Index (PASI), histopathology, and the signature cytokines of psoriasis (IL-23, IL-17, IL-22 and TNF-α). The mRNA and protein levels of inflammatory cytokines were quantified by quantitative real-time PCR (QRT-PCR) and ELISA. The expressions of signaling proteins MAPKs and NF-κB p65 were analyzed using western blotting. Electrophoretic mobility shift assay (EMSA) was used to check NF-κB p65 DNA binding activity.

RESULTS

Our study showed that RvD1 alleviated IMQ-induced psoriasiform dermatitis and improved skin pathological changes. RvD1 markedly inhibited IMQ-induced activation of ERK1/2, p38, JNK (c-Jun N-terminal protein kinase, a subfamily of MAPKs), and NF-κB. Furthermore, pretreatment with Boc, would not exacerbate skin inflammation of IMQ-induced mice, but significantly reversed the beneficial effects of RvD1 on IMQ-induced psoriasiform inflammation.

CONCLUSION

RvD1 can obviously improve skin inflammation in IMQ-induced mice psoriasiform dermatitis. The protective mechanisms might be related to its selective reaction with lipoxin A4 receptor/Formyl-peptide receptor 2 (ALX/FPR2), by downregulating relevant cytokines of the IL-23/IL-17 axis expression, the inhibition of MAPKs and NF-κB signaling transduction pathways. Thus, these results show that RvD1 could be a possible candidate for psoriasis therapy.

Activation of STAT3 integrates common profibrotic pathways to promote fibroblast activation and tissue fibrosis

Signal transducer and activator of transcription 3 (STAT3) is phosphorylated by various kinases, several of which have been implicated in aberrant fibroblast activation in fibrotic diseases including systemic sclerosis (SSc). Here we show that profibrotic signals converge on STAT3 and that STAT3 may be an important molecular checkpoint for tissue fibrosis. STAT3 signaling is hyperactivated in SSc in a TGFβ-dependent manner. Expression profiling and functional studies in vitro and in vivo demonstrate that STAT3 activation is mediated by the combined action of JAK, SRC, c-ABL, and JNK kinases. STAT3-deficient fibroblasts are less sensitive to the pro-fibrotic effects of TGFβ. Fibroblast-specific knockout of STAT3, or its pharmacological inhibition, ameliorate skin fibrosis in experimental mouse models. STAT3 thus integrates several profibrotic signals and might be a core mediator of fibrosis. Considering that several STAT3 inhibitors are currently tested in clinical trials, STAT3 might be a candidate for molecular targeted therapies of SSc.

STAT3 is a transcription factor that is activated in fibrotic diseases such as systemic sclerosis. Here the authors show that STAT3 is the converging point for multiple pro-fibrotic signalling pathways, and that its genetic ablation or inhibition ameliorate skin fibrosis in mouse models.