Topical Application Of Imiquimod Research Articles

A simple tool for evaluation of inflammation in psoriasis: Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio as markers in psoriasis patients and related murine models of psoriasis-like skin disease

Objective parameters to quantify psoriatic inflammation are needed for interdisciplinary patient care, as well as preclinical experimental models. This study evaluates neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in psoriasis patients and five murine models of psoriasis-like skin disease based on topical imiquimod application and overexpression of IL-17A under different promotors. We performed a single-center prospective observational study in a German population, investigating psoriasis patients prior to, 4 weeks, and 16 weeks post begin of systemic anti-inflammatory therapy. Psoriasis area and severity index (PASI), blood count, and C-reactive protein (CRP) levels were attained at each timepoint. Additionally, five murine models of psoriasis-like skin disease involving five distinct experimental procedures differing in time of disease-onset and severity were investigated regarding PLR and NLR. Of 43 recruited psoriasis patients, 34 patients were followed up to 16 weeks. The cohort was 69.77% male, showing a median age of 32.0 years (range 19.0–67.0; IQR 26). The median PASI decreased from 16.35 (8.0–50.0; 10.20) to 1.6 (0–10.3; 2.56) after 16 weeks of systemic therapy. Spearman’s correlation showed statistically significant positive correlation for NLR with PASI (rs = 0.27, p = 0.006), however not for PLR. NLR, but not PLR, was significantly associated with PASI in a multiple linear regression analysis including age, sex, psoriasis arthritis, and smoking. In the murine models of psoriasis-like skin disease, both NLR and PLR were significantly increased in the acute-severe models compared to controls (p < 0.001, p = 0.005, and p = 0.02, respectively), demonstrating gradually less increased values from severe-acute to mild-late-onset psoriatic phenotype. NLR was significantly associated with PASI in psoriatic patients as well as psoriatic phenotype in different murine psoriasis models. Our data warrants investigation of NLR in psoriasis patients and preclinical psoriasis models as an objective biomarker of psoriatic skin inflammation.Key messagesNLR, but not PLR, showed a statistically significant positive correlation with Psoriasis Area and Severity Index (PASI) in our human psoriasis cohort.Both NLR and PLR were significantly increased in murine psoriasis models compared to matched controls, with gradually less increased values from severe-acute to mild-late-onset psoriatic phenotype.NLR may represent an easily available, cheap, and objective parameter to monitor psoriatic inflammation in both clinical patient routine, as well as preclinical experimental murine models.

Characterization of spinal microglial activation in a mouse model of imiquimod-induced psoriasis

Although microglia are associated with chronic pain, the role of spinal microglia in the regulation of itch remains unclear. In this study, we characterized spinal microglial activation in a mouse model of imiquimod (IMQ)-induced psoriasis. Hypertrophic (activated) microglia were observed throughout the spinal cord after the topical application of IMQ. Furthermore, the mRNA expression of microglial markers and inflammatory mediators was upregulated. Ablation of itch-related sensory neurons using resiniferatoxin decreased itch-related scratching behavior and the number of hypertrophic microglia in the spinal dorsal horn. Conclusively, sensory neuron input may partially contribute to spinal microglial activation after IMQ application.

Co-occurrence of non-alcoholic steatohepatitis exacerbates psoriasis associated with decreased adiponectin expression in a murine model.

Clinical studies have suggested a bidirectional association between non-alcoholic steatohepatitis (NASH) and psoriasis, affecting each other's development and severity. Here, we explored bidirectional causal linkages between NASH and psoriasis using a murine model. NASH was induced in mice by streptozotocin injection at 2 days of age and by high-fat diet feeding (STAM™ model). Psoriasis was induced by topical application of imiquimod (IMQ) on the ear. The severities of liver damage and psoriatic skin changes were determined using histological analysis. Gene expression in the skin tissues was evaluated using quantitative PCR analysis. Serum cytokine levels were determined using enzyme-linked immunosorbent assay. To examine the innate immune responses of normal human epidermal keratinocytes (NHEKs), the cells were treated with interleukin (IL)-17A, tumor necrosis factor (TNF)-α, and AdipoRon, an adiponectin receptor agonist. There were no differences in the degree of liver tissue damage (fat deposition, inflammation, and fibrosis) between NASH mice with and those without psoriasis. Conversely, the co-occurrence of NASH significantly augmented psoriatic skin changes, represented by epidermal hyperplasia, in psoriatic mice. Pro-inflammatory cytokines were expressed in the inflamed skin of psoriatic mice, and the expression of genes, especially Il23a, Il1b, Il36g, and Mip2, was significantly upregulated by the co-occurrence of NASH. The expression of keratinocyte activation marker genes Defb4b and Krt16 was also upregulated by the co-occurrence of NASH. The serum TNF-α and IL-17 levels were increased by the co-occurrence of NASH and psoriasis. The serum adiponectin levels decreased in NASH mice compared with that in non-NASH mice. In NHEK culture, TNF-α and IL-17A synergistically upregulated CXCL1, CXCL8, and IL1B expression. The upregulated pro-inflammatory gene expression was suppressed by AdipoRon treatment, reflecting the anti-inflammatory capacity of adiponectin. The co-occurrence of NASH exacerbated psoriatic skin changes associated with increased serum inflammatory cytokine levels and decreased serum adiponectin levels. Combined with in vitro findings, increased inflammatory cytokine levels and decreased adiponectin levels likely promote innate immune responses in epidermal keratinocytes in psoriatic skin lesions. Overall, therapeutic intervention for co-occurring NASH is essential to achieve a favorable prognosis of psoriasis in clinical practice.

The opposite effect of tapinarof between IMQ and IL-23 induced psoriasis mouse models.

Tapinarof is an aryl hydrocarbon receptor (AHR) ligand which is used to treat plaque psoriasis in adults. However, the underlying mechanism is not yet fully understood. In this study, we applied two of the most studied psoriasis mouse models: topical application of imiquimod (IMQ) and subcutaneous injection of IL-23. Although both models successfully induced psoriasis-like lesions in mice, tapinarof had a completely opposite effect on the two models. Tapinarof decreased the expression of multiple essential cytokines involved in the pathological IL-23/IL-17/IL-22 axis and ameliorated IMQ-induced psoriatic dermatitis, inhibiting keratinocyte proliferation and abnormal differentiation. However, in the IL-23-injection-model, tapinarof instead aggravated the disease. Here, tapinarof increased epidermal thickness and differentiated epidermal dysplasia in mice. Our data suggest that tapinarof may have different effects on varied types of psoriasis.

Macrophages mediate psoriasis via Mincle-dependent mechanism in mice

Psoriasis is currently considered to be an immune and inflammatory disease characterized by massive immune cells infiltration including macrophages. It has been reported that macrophage-inducible C-type lectin (Mincle) is essential to maintain the pro-inflammatory phenotype of M1 macrophages, however, its role and mechanisms in psoriasis remain largely unknown. A model of psoriasis was induced in mice by a daily topical application of imiquimod for 7 days. Role and mechanisms of Mincle in macrophage-mediated psoriasis were investigated in clodronate liposomes induced macrophage depletion mice followed by adoptively transferring with Mincle-expressing or -knockout (KO) macrophages, and in macrophage specific Mincle knockout mice (Mincleloxp/loxp/Lyz2-cre+/+). Finally, a Mincle neutralizing antibody was employed to the psoriasis mice to reveal the therapeutic potential for psoriasis by targeting Mincle. Mincle was highly expressed by M1 macrophages in the skin lesions of patients and mice with psoriasis. Clodronate liposomes-induced macrophage depletion inhibited psoriasis in mice, which was restored by adoptive transfer with Mincle-expressing macrophages but not by Mincle-KO macrophages. This was further confirmed in macrophage-specific Mincle-KO mice. Mechanistically, macrophages mediated psoriasis via the Mincle-Syk-NF-κB pathway as blocking macrophage Mincle inhibited Syk/NF-κB-driven skin lesions and epidermal injury in vivo and in vitro. We also found that LPS induced Mincle expression by M1 macrophages via the PU.1-dependent mechanism. Most importantly, we revealed that targeting Mincle with a neutralizing antibody significantly improved psoriasis in mice. In summary, our findings demonstrated that macrophages mediate psoriasis in mice via the Mincle-dependent mechanism, targeting Mincle may represent as a novel therapy for psoriasis.A simplified pathway model of Mincle in macrophage-mediated psoriasis.

CD96 Blockade Ameliorates Imiquimod-Induced Psoriasis-like Dermatitis via Suppression of IL-17A Production by Dermal γδ T Cells.

Psoriasis is a chronic inflammatory skin disease. IL-23 plays a critical role in its pathogenesis by inducing production of IL-17A from pathological Th17 cells and IL-17A-producing γδ T cells. However, the mechanisms regulating the IL-23/IL-17 axis in psoriasis are incompletely understood. In this study, we show that, in comparison with wild-type mice, those deficient in the CD96 immunoreceptor had lower production of IL-17A in their dermal γδ T cells and milder psoriasis-like dermatitis after topical application of imiquimod (IMQ). Moreover, transfer of CD96-deficient dermal γδ T cells into the skin of Rag1-deficient mice resulted in them developing milder IMQ-induced dermatitis compared with Rag1-deficient mice transferred with wild-type dermal γδ T cells. In γδ T cells invitro, CD96 provides a costimulatory signal for the production of IL-23-induced IL-17A. In mice given an anti-CD96 neutralizing Ab, IL-17A production from dermal γδ T cells decreased and IMQ-induced dermatitis was milder compared with mice given a control Ab. These results suggest that CD96 is a potential molecular target for the treatment of psoriasis.

Assessing Antipsoriatic Effects of Bitter Pu’er Tea and Its Three Major Compounds, Strictinin, Theacrine and Epigallocatechin Gallate, in Imiquimod-Treated Mice

Psoriasis is a chronic inflammatory skin disease with hyperproliferation and aberrant differentiation of keratinocytes in association with the elevation of interleukin-17A (IL-17A) and IL-23 levels. In an animal model, psoriasis-like dermatitis was induced on the shaved dorsal skin of BALB/c mice by topical application of imiquimod (IMQ), a synthetic ligand of Toll-like receptor 7. Administration of bitter Pu’er tea significantly reduced psoriasis-like dermatitis in IMQ-treated mice, including a reduction in dorsal skin lesions, splenomegaly and the mRNA expression levels of IL-17A and IL-23. To examine putative antipsoriatic constituents, three major compounds in bitter Pu’er tea, strictinin, theacrine and epigallocatechin gallate (EGCG), were separately given as supplements to IMQ-treated mice. The results showed that all the three compounds attenuated the severity of psoriasis by reducing epidermal thickness. Only theacrine significantly attenuated splenomegaly. All the three compounds inhibited the expression of IL-23 mRNA in the skin as well as reduced the content of IL-17A+CD4+ T cells in the spleen, and strictinin was found to be relatively effective. It seemed that the antipsoriatic activity of bitter Pu’er tea was attributed to the additive effects of its multiple active compounds.

Inhibition of JAK1/STAT3 pathway by 2-methoxyestradiol ameliorates psoriatic features in vitro and in an imiquimod-induced psoriasis-like mouse model

Psoriasis is characterized by hyperproliferative keratinocytes, dilated capillaries and leukocyte infiltration. 2-Methoxyestradiol (2-ME) has shown significant inhibition on proliferation, angiogenesis and inflammation. To evaluate the anti-psoriatic potential of 2-ME, psoriasis-like dermatitis was induced by topical application of imiquimod (IMQ) on the dorsal skin of C57BL/6 mice for seven consecutive days, followed by treatment of vehicle or 2-ME ointment from Day 4 on. The psoriasis area and severity index (PASI) was assessed daily. On Day 8, skin histology and spleen index were assessed. The effects of 2-ME on the proliferation, apoptosis, cell cycle, vascular endothelial growth factor A (VEGFA), and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathways of HaCaT cells stimulated by interleukin-17 (IL-17A) were detected, together with its effect on the proliferation, tube formation and VEGF receptor expression of human umbilical vein endothelial cells (HUVECs). We found that topical 2-ME treatment significantly improved IMQ-induced psoriasis-like dermatitis and decreased the PASI scores, the activation of STAT3 in the skin (P < 0.05), and the spleen index in mice (P < 0.01). In vitro, 2-ME inhibited the proliferation of HaCaT cells by inducing apoptosis and G2/M phase arrest (P < 0.01). Moreover, 2-ME suppressed IL-17A-induced VEGFA (2.5 μM: P < 0.05; 5 μM: P < 0.01) and phosphorylation of STAT3 by blocking p-JAK1 in HaCaT cells and prevented tube formation (P < 0.01) and proliferation by targeting VEGF receptors 1 (VEGFR1) and 2 (VEGFR2) in HUVECs. We conclude that 2-ME alleviated psoriasis in vivo and in vitro by inhibiting JAK1/STAT3 pathway and was a promising therapeutic agent for psoriasis.

MiRNA-203b-3p Induces Acute and Chronic Pruritus through 5-HTR2B and TRPV4

Growing evidence indicates that transient receptor potential (TRP) channels contribute to different forms of pruritus. However, the endogenous mediators that cause itch through transient receptor potential channels signaling are poorly understood. In this study, we show that genetic deletion or pharmacological antagonism of TRPV4 attenuated itch in a mouse model of psoriasis induced by topical application of imiquimod. Human psoriatic lesions showed increased expression of several microRNAs, including the miR-203b-3p, which induced a calcium ion response in rodent dorsal root ganglion neurons and scratching behavior in mice through 5-HTR2B activation and the protein kinase C‒dependent phosphorylation of TRPV4. Computer simulation revealed that the miR-203b-3p core sequence (GUUAAGAA) that causes 5-HTR2B/TRPV4-dependent itch targets the extracellular side of 5-HTR2B by interacting with a portion of the receptor pocket consistent with its activation. Overall, we reveal the unconventional pathophysiological role of an extracellular microRNA that can behave as an itch promoter through 5-HTR2B and TRPV4.

Treatment of basal cell carcinoma: An overview

Basal cell carcinoma (BCC) is the most common cutaneous cancer worldwide, but accounts for only 2–4% of skin cancers in Asian population. Tumor characteristics such as size, location, pathology, and risk of recurrence, as well as treatment tolerability, cost, and patient preference influence the selection of treatment. The goal of treatment is complete tumor removal in superficial/locally invasive BCCs and prolongation of survival in the rare setting of metastatic BCC. Various treatment options available include conventional surgical excision, Mohs micrographic surgery, cryosurgery, electrodesiccation and curettage, topical application of imiquimod or 5-fluorouracil, and photodynamic, and radiotherapy. Surgical excision and Mohs surgery are preferred because of low recurrence rate and the possibility to evaluate the clearance through histology. In the treatment of metastatic or locally advanced lesions, hedgehog pathway inhibitors and the recently approved drug cemiplimab can be beneficial. Sun protection and regular skin self-checks are recommended for all patients with BCC. This literature review gives an overview of the treatment of BCC.

Abstract CT245: First in human CD200 activation receptor ligand and tumor lysate vaccine immunotherapy for recurrent glioblastoma in adults

Abstract Background: Immunotherapy has revolutionized clinical management of malignancies rendering cancers that previously had a dismal prognosis more manageable. Unfortunately, these therapies can cause serious immune-related adverse events, including death. In CNS cancers, currently available immunotherapies have limited to no efficacy. Our work in glioblastoma (GBM), which is considered one of the most aggressive cancers as well as being universally fatal, is focused on the CD200 immune checkpoint that modulates the immune system through the inhibitory receptor (CD200R1) and activation receptor (CD200AR). The peptide checkpoint ligand (CD200AR-L) was developed to target the CD200AR that downregulates the inhibitory PD-1/PD-L1, CTLA4 and CD200R immune checkpoints, permitting immune system activation that is less hampered by the inhibitory effects of GBM. Following a positive clinical trial in dogs that spontaneously developed high-grade gliomas, we initiated a first-in-human Phase 1 Study of the CD200 Activation Receptor Ligand (CD200AR-L) and Allogeneic Tumor Lysate Vaccine (GBM6-AD) immunotherapy for Recurrent Glioblastoma (NCT04642937). Methods: This is a single-center, first-in-human, dose-escalation Phase 1 clinical trial utilizing a 3+3 design at three dose levels; 3.75micrograms/kg, 5micrograms/kg, and 7.25micrograms/kg. Adults 18 years and old with recurrent GBM and no pre-exiting immune-related condition plus adequate performance score were eligible. Accrual started in December 2020 at dose level 1 with a second cohort having received treatment on dose level 2. CD200AR-L is administered on days 1 and 2 by suprascapular intradermal injection following the application of topical imiquimod. On day 2, a fixed dose of the allogeneic vaccine is injected intradermally at the same site. The “Induction Phase” consists of this injection series weekly for 4 weeks with monitoring for dose-limiting toxicity through Day28. The “Maintenance Phase” doses the vaccine series monthly for 2 months, then the “Booster Phase” doses every eight weeks for 24 months or until end of treatment. Patients are monitored for adverse events, including immune-mediated intracranial edema and other immune-related complications, and their neurological function is scored per NANO criteria. Correlative studies include immune monitoring (including expression of CD200R1, PD1/PD-L1, and CTLA-4) and MRI imaging assessment per iRANO criteria. Citation Format: Michael R. Olin, Elizabeth C. Neil, Anne Eaton, Shannon Lunn, Christopher L. Moertel. First in human CD200 activation receptor ligand and tumor lysate vaccine immunotherapy for recurrent glioblastoma in adults [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT245.

Systemic TLR7/8 micelles trigger a novel and potent anti-tumor response by strong recruitment of neutrophils leading to massive tumor cell killing.

2576 Background: Clinical use of TLR7/8 agonists is currently restricted to topical application of Imiquimod for treatment of superficial basal cell carcinoma since systemic administration is prevented due to dose-limiting toxicity. Here, we present a novel micelle-based drug delivery technology containing a lipid-anchored TLR7/8 agonist for intravenous administration. The MBS8 formulation shows good efficacy in mouse cancer models, is well tolerated in rodents and non-human primates and is currently being tested in clinical studies (NCT04855435). Methods: MBS8 was tested in 12 syngeneic mouse cancer models as monotherapy or in combination anti-PD-1 and anti-PD-L1 antibodies. MBS8 was administered IV as slow bolus. Tumors and spleens were analysed using histology, immunohistochemistry, ELISPOT and flow cytometry. Phenotyping of tumor microenvironment was done using flow cytometry and Nanostring analyses. Safety and tolerability were tested in mice, rats and monkeys. Safety-related and PD biomarkers were identified in monkeys using a multiplex MSD technology and validated in whole human blood stimulated with MBS8 ex-vivo. Results: In several syngeneic mouse tumor models, MBS8 led to complete eradication of established tumors. The complete responders showed tumor rejection upon re-challenge. In these mice, a CD8+-dependent tumor-specific immune memory response was evident. Tumors demonstrated a massive tissue necrosis ( &gt; 80%) within 24-48h after the first drug administration and showed massive neutrophil infiltration 6h after dosing. Antigen specific CD8+ T-cells were detected in tumors 24 hours after treatment with increased CD8+:Treg cell ratio and enhanced antigen presentation in tdLN. MBS8 showed both additive and synergistic effect when combined with anti-PD-1 or anti-PD-L1 antibody treatment. Moreover, in tumors being resistant to anti-PD-1 treatment, co-administration of MBS8 reverted sensitivity to anti-PD-1 treatment in a synergistic manner. A panel of cytokines induced by MBS8 upon repeat dose administration in monkeys was identified in plasma as potential biomarkers. Ten of them were further evaluated in whole human blood treated with MBS8 ex vivo. Currently, these cytokines are being used in Phase I clinical studies. Conclusions: MBS8 showed significant anti-cancer activity in multiple in vivo solid tumor models when administered either as monotherapy or in combination with ICIs. MBS8 demonstrated a novel mode of action with neutrophils playing a central role as primary effector cells causing a rapid killing of tumors. Further, adaptive immune response was initiated including generation of tumor specific CD8+ cells and establishment of the immune memory. MBS8 was well tolerated in rodents and cynomolgus monkeys at the dose levels above therapeutic effective doses identified in mice, thus providing a good therapeutic window.

Dietary olive oil intake aggravates psoriatic skin inflammation in mice via Nrf2 activation and polyunsaturated fatty acid imbalance

Psoriasis is a chronic inflammatory skin disease, which does not have effective treatment options. However, olive oil has been suggested as an alternative to treat psoriasis, but no study has evaluated the mechanisms involved in the effects of olive oil on psoriasis. Thus, the current study investigated whether olive oil could ameliorate psoriasiform skin inflammation. To test this, mice received topical application of imiquimod to induce inflammation and were treated orally with olive oil. Human immortalized keratinocytes were also treated with imiquimod and olive oil. Epidermal thickness and keratinocyte proliferation were increased in imiquimod-induced lesions of olive-oil-treated animals. In both in vitro and in vivo studies, protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2) were elevated following imiquimod and olive oil administration. Inhibition of Nrf2 abolished the increased proliferation of keratinocytes treated with imiquimod and olive oil, demonstrating the role of Nrf2 in olive oil-mediated exacerbation of psoriasiform skin inflammation. In addition, lower levels of linoleic acid and higher levels of oleic acid were observed in imiquimod- and olive-oil-treated animals, which may also contribute to the adverse effects of olive oil on psoriasis. In conclusion, dietary intake of olive oil aggravates the symptoms of psoriatic skin lesions through the overexpression of Nrf2 and an imbalance in oleic and linoleic acids levels, suggesting that a diet rich in olive oil may have significant negative effects on psoriasis.

Topical Formulation of Noscapine, a Benzylisoquinoline Alkaloid, Ameliorates Imiquimod-Induced Psoriasis-Like Skin Lesions.

Psoriasis is considered an autoimmune inflammatory disease. The disease is spread and diagnosed by the infiltration of inflammatory mediators and cells into the epidermis. Recent theoretical developments have focused on the effectiveness of noscapine (NOS) as a potential alkaloid for being used as a valuable treatment for different diseases. In the present study, psoriasis-like dermatitis was induced on the right ear pinna surface of male Balb/c mice by topical application of imiquimod (IMQ) for ten consecutive days, which was treated with noscapine (0.3, 1, 3, and 10% w/v) or clobetasol (0.05% w/v) as a positive control. The levels of ear length, thickness, severity of skin inflammation, psoriatic itch, psoriasis area severity index (PASI) score, and body weight were measured daily. On the 10th day of study, each ear was investigated for inflammation, fibrosis, proliferation, and apoptosis using histopathological (H&E and Masson's trichrome staining) and immunohistochemistry (Ki67 and p53 staining) assays. Furthermore, the levels of inflammatory biomarkers were characterized by an enzyme-linked immunosorbent assay (ELISA). The results confirmed IMQ-induced psoriasis for five consecutive days. In contrast, noscapine significantly reduced the ear length, thickness, severity of skin inflammation, psoriatic itch and body weight, tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), interferon-gamma (IFN-γ), interleukin 6 (IL-6), IL-17, and IL-23p19 in a concentration-dependent manner (P < 0.001–0.05 for all cases). Overall, topical noscapine significantly ameliorated both the macroscopical and microscopical features of psoriasis. However, further clinical investigations are required to translate the effects to clinics.

Therapeutic effects of the extract of Sancao Formula, a Chinese herbal compound, on imiquimod-induced psoriasis via cysteine-rich protein 61

ObjectivePsoriasis is a common chronic inflammatory skin disease that is prone to recurrence, and the proinflammatory factor, cysteine-rich protein 61 (Cyr61), is important in its pathophysiology. Long-term clinical practice has shown that Sancao Formula (SC), a Chinese herbal compound, is effective in the treatment of psoriasis, but the precise mechanism remains unknown. In this study, we investigate the mechanism by which SC extract alleviates imiquimod (IMQ)-induced psoriasis. MethodsThe expression of Cyr61 in psoriatic lesions and normal healthy skin was detected using immunohistochemical analysis to investigate the biological role of Cyr61 in models of psoriatic inflammation. A psoriatic mouse model was established by topical application of IMQ, and the effect of topical application of SC extract was evaluated using the psoriasis area and severity index (PASI) score, hematoxylin-eosin staining, and histopathological features of the skin. Next, a HaCaT cell inflammation model was established using interferon-γ (IFN-γ), and the effect of SC extract on the mRNA and protein levels of Cyr61 and intercellular cell adhesion molecule-1 (ICAM-1) was confirmed using Western blot and quantitative real-time polymerase chain reaction analyses. ResultsImmunohistochemical staining showed that the expression of Cyr61 in psoriatic lesions was higher than that in normal skin samples (78.26% vs 41.18%, P < 0.05), and the number of Cyr61-positive cells in psoriatic lesions was also significantly higher than in normal skin (18.66 ± 2.51 vs 4.33 ± 1.52, P < 0.05). Treatment in mice with IMQ-induced psoriasis showed that SC extract could significantly improve the inflammatory phenotype, PASI score (10.875 ± 0.744 vs 3.875 ± 0.582, P < 0.05), and pathological features compared with those in IMQ model group; SC treatment was also associated with decreased levels of Cyr61 and ICAM-1. In the IFN-γ-induced inflammatory cell model, the mRNA and protein levels of Cyr61 and ICAM-1 were upregulated, while the SC extract downregulated the levels of Cyr61 and ICAM-1. ConclusionThe results provide a theoretical basis for the involvement of Cyr61 in the pathogenesis of psoriasis, and suggest that SC should be used to target Cyr61 for the prevention of psoriasis recurrence.

LncRNA MEG3 suppresses PI3K/AKT/mTOR signalling pathway to enhance autophagy and inhibit inflammation in TNF-α-treated keratinocytes and psoriatic mice.

Psoriasis is a common chronic inflammatory skin disorder that causes patches of thick red skin and silvery scales and affects 1-3% of the population, which reduces patient's quality of life. Understanding the pathogenesis of psoriasis is crucial for developing novel therapeutic strategies. HaCaT and NHEK cells were treated with TNF-α in vitro. A mouse model of psoriasis was established by topical imiquimod application on back skin. LncRNA MEG3 was cloned into the pcDNA3.1 vector and transfected in TNF-α-treated HaCaT and NHEK cells to overexpress its expression. Liposome-encapsulated pcDNA3.1-MEG3 was injected into imiquimod-treated mice via tail vein. RT-qPCR and western blot assays were used to examine the expression of lncRNA MEG3, IL-6, IL-8, IFN-γ, IL-1β, LC3, Beclin 1, p62, p-p65, p65, NLRP3, p-PI3K, PI3K, p-AKT, AKT, p-mTOR, mTOR respectively. The secretion of IL-6, IL-8, IFN-γ and IL-1β was determined using ELISA assay. Immunofluorescence and immunohistochemistry methods were performed for analyzing the expression of LC3 and NLRP3 in cells and skin tissues respectively. LY294002 was used to block the PI3K/AKT/mTOR signalling. MTT assay was applied to test the toxicity of LY294002 to HaCaT and NHEK cells. LncRNA MEG3 expression levels were downregulated in TNF-α-treated HaCaT and NHEK cells and skin tissues of psoriatic mice model. TNF-α treatment enhanced inflammation and suppressed autophagy in HaCaT and NHEK cells, which were largely reversed by overexpression of lncRNA MEG3. Autophagy puncta and NLRP3 inflammasome assembly showed the same patterns with the expression of inflammation and autophagy markers in TNF-α-treated HaCaT and NHEK cells with or without lncRNA MEG3 overexpression. TNF-α-induced activation of the PI3K/AKT/mTOR signalling was abolished by lncRNA MEG3 overexpression in HaCaT and NHEK cells. Blocking the PI3K/AKT/mTOR signalling inhibited TNF-α-induced inflammation and restored autophagy level in TNF-α-treated HaCaT and NHEK cells. Overexpression of lncRNA MEG3 suppressed inflammation, promoted autophagy and inhibited the activation of the PI3K/AKT/mTOR signalling in a mouse model of psoriasis. LncRNA MEG3 facilitates autophagy and suppresses inflammation in TNF-α-treated keratinocytes and psoriatic mice, which is dependent on the PI3K/AKT/mTOR signalling pathway. Our study enhances the understanding of psoriasis and provides potential therapeutic targets for psoriasis.

Acute induction of psoriasis-like skin inflammation disturbes vascular tone and provokes a rapid blood pressure response in mice

Abstract Background Psoriasis is the most common chronic skin disease worldwide. Furthermore, it is an independent cardiovascular risk factor. Several genetic and inducible murine models reproduce specific aspects of the human disease. In mice genetically overexpressing IL-17A in keratinocytes or dendritic cells, we coulod show both aspects of the disease: cutaneous hallmarks and the vascular phenotype. The most popular inducible model consists of topical application of Imiquimod (IMQ), a Toll-like receptor 7/8 agonist. In this model, cardiovascular aspects have not been studied yet. Therefore, we examined vascular and hemodynamic effects in this most popular murine psoriasis model. Methods C57BL/6J mice were treated with 5% IMQ or sham cream. During treatment, we measured bodyweight, skin thickness and skin water loss. After 10 days, aortic relaxation studies were performed. For assessment of vascular inflammation, inflammatory cell infiltration into the aortic tissue was investigated by flow cytometric analysis. To record physical activity, blood pressure and heart rate, carotid catheters were implanted two weeks before treatment with IMQ. Blood pressure and heart rate were continuously recorded by receiver platforms. Results IMQ treatment resulted in severe skin inflammation and induced a skin barrier defect resulting in a 7-fold increase of transcutaneous water loss (from 11±6 ml/m2h to 77±30 ml/m2h). Physical activity decreased more than 50% after d1 of treatment and normalized at d7. Telemetric recording revealed a reflex tachycardia at 1d of IMQ-application (from 492±21 bpm to 524±20 bpm) followed by a significant reduction of heart rate for the next two days (456±18bpm). Systolic blood pressure showed a similar trend: after a fast increase (from 120±13 mmHg to 127±18 mmHg), blood pressure dropped below baseline at d2/3 with a subsequent recovery. We could display a highly significant positive correlation between blood pressure and heart rate during the treatment (R=0.6; p≤0.0001). Aortas from animals after 10d of IMQ-treatment showed an increased infiltration of CD45+ and CD11b+ inflammatory cells but no change of responsiveness to endothelium dependent and independent vasodilators in organ chamber studies. Conclusion Skin treatment with IMQ had severe implications on the hemodynamic system: After an initial peak of heart rate and blood pressure, mice showed significantly lower values for two days with a subsequent full recovery. Moreover, bodyweight and physical activity were significantly altered during treatment. Our data indicate that skin inflammation and inflammatory skin barrier disruption by IMQ forces a compensatory whole-body response. 10 days of IMQ-treatment resulted in vascular inflammation without mediating vascular dysfunction. In summary, we could reveal that IMQ-induced psoriasis, as the most popular murine psoriasis model worldwide, has extensive effects on the cardiovascular system. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Boehringer Ingelheim Foundation “Novel and neglected cardiovascular risk factors: molecular mechanisms and therapeutic implications”German Federal Ministry for Education and Research (BMBF EDU-V24)

Repurposing the anthelmintic praziquantel to treat psoriasis.

The anthelmintic drug praziquantel has been used as a standard treatment for schistosomiasis for over 40 years. This study aimed to repurpose praziquantel to treat psoriasis. Psoriasis-like skin inflammation was induced in mice (C57 and Balb/C) by topical application of imiquimod or intradermal injection of recombinant IL-23. Praziquantel was either orally or topically administered during the psoriasis induction period. Mice treated with either oral or topical praziquantel exhibited markedly improved psoriasiform skin symptoms when compared with control mice, as judged by disease severity score, epidermal thickening, inflammatory cell infiltration and spleen size. Flow cytometric analysis of infiltrating immune cells from mouse skin displayed reduced infiltration of Th17 cells. In vitro experiments revealed that praziquantel inhibited STAT3 phosphorylation and RORγt expression in splenic CD4+ T-cells. Praziquantel also decreased STAT3 phosphorylation in HEK-A/F cells. Down-regulation of STAT3 phosphorylation in these cells accounts for the decreased number of Th17 cells and keratinocytes. These results provide the first preclinical evidence that praziquantel may effectively treat psoriasis, and suggest that praziquantel alleviates symptoms in mice by inhibiting STAT3 phosphorylation, thereby suppressing Th17 immune responses.

Curcumin alleviates imiquimod-induced psoriasis in progranulin-knockout mice

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

IFN-κ Is a Rheostat for Development of Psoriasiform Inflammation

Psoriasis is a common, inflammatory autoimmune skin disease. Early detection of an IFN-1 signature occurs in many psoriasis lesions, but the source of IFN production remains debated. IFN-κ is an important source of IFN-1 production in the epidermis. We identified a correlation between IFN-regulated and psoriasis-associated genes in human lesional skin. We thus wanted to explore the effects of IFN-κ in psoriasis using the well-characterized imiquimod psoriasis model. Three mouse strains aged 10 weeks were used: wild-type C57Bl/6, C57Bl/6 that overexpress Ifnk in the epidermis (i.e., transgenic), and total body Ifnk-/- (i.e., knockout) strain. Psoriasis was induced by topical application of imiquimod on both ears for 8 consecutive days. Notably, the severity of skin lesions and inflammatory cell infiltration was more significantly increased in transgenic than in wild-type than in knockout mice. Gene expression analysis identified greater upregulation of Mxa, Il1b, Tnfa, Il6, Il12, Il23, Il17, and Ifng in transgenic compared to wild-type compared to knockout mice after imiquimod treatment. Furthermore, imiquimod increased CD8+ and CD4+ T-cell infiltration more in transgenic than in wild-type than in knockout mice. In summary, we identified IFN-κ as a rheostat for initiation of psoriasiform inflammation. This suggests that targeting IFN-1s early in the disease may be an effective way of controlling psoriatic inflammation.