Psoriatic inflammation causes hepatic inflammation with concomitant dysregulation in hepatic metabolism via IL-17A/IL-17 receptor signaling in a murine model

HMGB1 regulates Th17 cell differentiation and function in patients with psoriasis

BACKGROUND

Psoriasis is an immune-mediated chronic inflammatory skin disease, in which T helper 17 (Th17) cells and its effective cytokine interleukin (IL)-17A play a pivotal pathogenic role. High mobility group box 1 (HMGB1) is an important proinflammatory cytokine, which has been confirmed to be highly expressed in the peripheral circulation and epidermis tissues of psoriasis patients. The regulatory effect of HMGB1 on IL-17A expression and function has been reported in some inflammatory and autoimmune diseases by the HMGB1-Toll-like receptor 4 (TLR4)-interleukin (IL)-23-IL-17A pathway. While, in the pathological environment of psoriasis, whether HMGB1 can exert the regulatory effect on IL-17A is not clear.

OBJECTIVE

We aimed to evaluate the role of HMGB1-TLR4-IL-23-IL-17A pathway in the pathogenesis of psoriasis and explore the possible regulatory mechanism of HMGB1 on Th17 cell differentiation.

METHODS

Serum levels of HMGB1, TLR4, IL-23, and IL-17A were quantified in 50 patients with moderate-to-severe plaque psoriasis and 30 healthy controls. Peripheral blood mononuclear cells  were acquired from 10 severe psoriasis patients and administrated by different concentrations of recombinant-HMGB1 (rHMGB1) to detect the Th17 cell percentage, mRNA and protein levels of TLR4, IL-23, IL-17A and retinoid-related orphan receptor γt (RORγt).

RESULTS

The serum levels of HMGB1, TLR4, IL-23, and IL-17A in psoriasis patients were significantly higher than healthy controls, especially in severe patients, and positively correlated with the severity index. There were also positive correlations between every two detected indicators of HMGB1, TLR4, IL-23, and IL-17A. In vitro study, rHMGB1 can promote the elevated expression of Th17 cell percentage as well as TLR4, IL-23, IL-17A, and RORγt in a dose-dependent manner.

CONCLUSION

HMGB1 can contribute to the pathogenesis of psoriasis by regulating Th17 cell differentiation through HMGB1-TLR4-IL-23-RORγt pathway, then promotes IL-17A production and aggravates inflammation process. Targeting HMGB1 may be a possible potential candidate for the immunotherapy of psoriasis.

Attenuated effects of topical vinpocetine in an imiquimod-induced mouse model of psoriasis

Psoriasis is an uncontrolled, long-lasting inflammatory dermatosis distinguished by thickened, erythematous, and flaky skin lesions. Massive amounts of inflammatory cytokines are produced when immune system imbalances are driven by genetic and environmental triggers. Vinpocetine (VNP), a man-made analogue of the compound vincamine found in the dwarf periwinkle herb, has robust anti-inflammatory, immunomodulatory, and anti-oxidative effects; alleviates the epidermal penetration of immune cells, such as eosinophils and neutrophils; and abolishes the generation of pro-inflammatory molecules.

Objective

This study was aimed at exploring the effects of long-term topical VNP, both alone and co-administered with clobetasol propionate, in an imiquimod-induced mouse model of psoriasiform dermatitis.

Methods

The study protocol consisted of 48 Swiss albino mice, randomly divided into six groups of eight mice each. In group I, petroleum jelly was administered daily for 8 days. In group II, imiquimod was administered topically at 62.5 mg daily for 8 days. In groups III, VI, V, and VI, 0.05% clobetasol propionate, 1% VNP, 3% VNP, and 3% VNP plus 0.05% clobetasol were administered topically for an additional 8 days after the induction, thus resulting in a total trial length of 16 days.

Results

Topical VNP at various doses alleviated the severity of imiquimod-induced psoriatic lesions-including erythema, silvery-white scaling, and thickening-and reversed the histopathological abnormalities. Moreover, imiquimod-exposed animals treated with VNP showed markedly diminished concentrations of inflammatory biomarkers, including tumour necrosis factor-α, interleukin (IL)-8, IL-17A, IL-23, IL-37, nuclear factor-kappa B (NF-κB), and transforming growth factor-β1.

Conclusion

This research provides new evidence that VNP, alone and in combination with clobetasol, may serve as a potential adjuvant for long-term management of autoimmune and autoinflammatory skin diseases, particularly psoriasis, by attenuating psoriatic lesion severity, suppressing cytokine generation, and limiting NF-κB-mediated inflammation.

Deucravacitinib and shikonin combination therapy ameliorates imiquimod-induced psoriasis in mice

INTRODUCTION

TYK2 inhibitors and traditional natural drugs as promising drugs for psoriasis therapy are receiving increasing attention. They both affect different molecules of JAK/STAT pathway, but it is currently unclear whether their combination will enhance the effect on psoriasis. In this study, we used imiquimod (IMQ)-induced psoriasis mouse model to investigate the therapeutic effects of the combined administration of deucravacitinib (TYK2 inhibitor) and shikonin.

METHODS

Aldara cream containing 5% IMQ was used to topically treat the dorsal skin of each mouse for a total of six consecutive days to induce psoriasis. The psoriasis area and severity index (PASI) scores were recorded every day. On the 7th day, skin tissues were taken for histopathological examination and the content of cytokines in skin were evaluated. The frequency of immune cells in peripheral blood, spleen and skin were detected through flow cytometry.

RESULTS

Compared to the vehicle control group, the psoriasis symptoms and immune disorder improved significantly in the combination therapy group and deucravacitinib treatment group on the 7th day, and the expressions of p-STAT3 and Ki67 in skin were reduced as well. Moreover, the combined treatment of deucravacitinib and shikonin for psoriasis was superior to the monotherapy group, especially in inhibiting abnormal capillaries proliferation, reducing immune cells infiltration and decreasing the concentration of IL-12p70 in skin.

CONCLUSION

The combination of deucravacitinib and shikonin is a promising clinical application.

The Prevalent Comorbidome at the Onset of Psoriasis Diagnosis

INTRODUCTION

Psoriasis (PsO) is currently regarded as a systemic inflammatory disease with a growing burden of post-diagnosis associated comorbidities. To determine the initial burden of comorbiditis we evaluated the comorbidome at PsO onset.

METHODS

In a matched case-control study, we extracted data on 57,228 patients and 125 morbidities from the Clalit Health Services Israeli insurance database. PsO cases were matched with control individuals by sex and age at enrolment. As pre-existing comorbidities, we considered all conditions already present in controls at the same age as the matched PsO case at the time of their diagnosis. To test for differences in the odds of comorbidities between the case and control groups, logistic regression analyses were run to calculate the odds ratio (OR) for each comorbidity, after which the comorbidome was graphically represented.

RESULTS

In this study we enrolled 28,614 PsO patients and 28,614 controls with an average age of 45.3 ± 19.6 years. At the time of diagnosis, PsO patients were more likely to be diagnosed with 2-4 comorbidities (28.8% vs 23.8%) and > 5 (19.6% vs 12.9%,). PsO patients' specific comorbidomes evidenced several pathological cores: autoimmune and inflammatory systemic diseases [i.e., hidradenitis suppurativa (OR 3.55, 95% CI 1.88-7.28) or polymyalgia rheumatica (OR 3.01 95% CI 1.96-4.77)], inflammatory bowel diseases [i.e., Crohn's disease (OR 2.99 95% CI 2.20-4.13)], pulmonary inflammatory diseases [i.e., chronic obstructive pulmonary disease (OR 1.81 95% CI 1.61-2.04)], hepatological diseases [i.e., cirrhosis (OR 2.00 95% CI 1.36-3.00)], endocrine diseases [dysthyroidisms (OR 1.82 95% CI 1.30-2.59)], mental disorders [i.e., depression (OR 1.72 95% CI 1.57-1.87)], and cardiovascular diseases (i.e., hypertension (OR 1.47 95% CI 1.41-1.53)].

CONCLUSION

The PsO-onset comorbidome may help health professionals plan more comprehensive patient management. By screening for these common PsO-linked conditions, early diagnosis and treatment may become more frequent, thus greatly benefiting patients on their medical journey.

Effect of vitamin D deficiency on postorthodontic relapse: An animal study

OBJECTIVES

This study aims to evaluate the effect of vitamin D deficiency (VDD) on orthodontic tooth movement (OTM), retention, and relapse and to assess the effect of systemic administration of vitamin D (VD) in a rat model.

MATERIALS AND METHODS

A total of 32 male Wistar rats were divided into two groups, a control group of 11 rats and an experimental group of 21 rats with VDD, after enhancement using a custom diet. Of the VDD group, 11 rats were supplemented with systemic vitamin D3 and categorized as vitamin (VD supplement [VDS]) groups. The VDS group received 40,000 IU/kg via intramuscular injection on Days 1 and 15 of the orthodontic treatment period. A modified orthodontic appliance was fitted to apply 0.5 N of force to move the maxillary right first molars mesially for 14 days, followed by retention and relapse periods for 7 days. Space created during OTM was measured and reassessed after the retention and relapse periods. The relapse ratio was estimated, and histomorphometric analysis was performed to assess the number of osteoblasts, osteoclast bone cells, and bone area.

RESULTS

A significant increase in the relapse ratio and a reduction in osteoblast cells and bone area were observed in the VDD group. By contrast, the amount of tooth movement was significantly higher together with osteoblast cells and bone marrow in VDS with a significant reduction in relapse ratio.

CONCLUSION

VDD was associated with a significant reduction in osteoblast cell count and total bone area in addition to a significant increase in relapse ratio. Routine screening of VD may be beneficial before commencing orthodontic treatment.

Interleukin-17 as a key player in neuroimmunometabolism

In mammals, interleukin (IL)-17 cytokines are produced by innate and adaptive lymphocytes. However, the IL-17 family has widespread expression throughout evolution, dating as far back as cnidaria, molluscs and worms, which predate lymphocytes. The evolutionary conservation of IL-17 suggests that it is involved in innate defence strategies, but also that this cytokine family has a fundamental role beyond typical host defence. Throughout evolution, IL-17 seems to have a major function in homeostatic maintenance at barrier sites. Most recently, a pivotal role has been identified for IL-17 in regulating cellular metabolism, neuroimmunology and tissue physiology, particularly in adipose tissue. Here we review the emerging role of IL-17 signalling in regulating metabolic processes, which may shine a light on the evolutionary role of IL-17 beyond typical immune responses. We propose that IL-17 helps to coordinate the cross-talk among the nervous, endocrine and immune systems for whole-body energy homeostasis as a key player in neuroimmunometabolism.

Crosstalk between cholesterol metabolism and psoriatic inflammation

Psoriasis is a chronic autoinflammatory skin disease associated with multiple comorbidities, with a prevalence ranging from 2 to 3% in the general population. Decades of preclinical and clinical studies have revealed that alterations in cholesterol and lipid metabolism are strongly associated with psoriasis. Cytokines (tumor necrosis factor-α (TNF-α), interleukin (IL)-17), which are important in the pathogenesis of psoriasis, have been shown to affect cholesterol and lipid metabolism. Cholesterol metabolites and metabolic enzymes, on the other hand, influence not only the biofunction of keratinocytes (a primary type of cell in the epidermis) in psoriasis, but also the immune response and inflammation. However, the relationship between cholesterol metabolism and psoriasis has not been thoroughly reviewed. This review mainly focuses on cholesterol metabolism disturbances in psoriasis and their crosstalk with psoriatic inflammation.

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.

Serum LL‐37 and inflammatory cytokines levels in psoriasis

Background

Psoriasis (PsO) is a T‐cell‐associated inflammatory autoimmune dermatitis. Leucine leucine‐37 (LL‐37) is upregulated in PsO patients and correlated with the area and severity of PsO. However, the exact relation between LL‐37 and T cell‐associated inflammation is not well understood. It is very important to clarify the relationship between LL‐37 and inflammatory response for clinical diagnosis and treatment of PsO. This study investigated the serum levels of LL‐37 and inflammatory cytokines, as well as correlations between them in PsO patients, which aimed to provide new ideas for the diagnosis and treatment of PsO.

Methods

PsO patients (n = 50) and healthy volunteers (n = 33) were recruited in this study. Skin specimens were stained with hematoxylin and eosin (H&E). The serum levels of LL‐37, T‐helper type 1 (Th1, IFN‐γ), T‐helper type 17 (Th17, IL‐17), T‐helper type 22 (Th22, IL‐22), and T‐helper type 2 cytokines (Th2, IL‐4) were assessed by enzyme‐linked immunosorbent assay. Some of the patients were re‐recruited after treatment to evaluate LL‐37 and cytokines levels.

Results

Pathological changes were observed in PsO skin lesions. LL‐37, IFN‐γ, IL‐17, and IL‐22 serum levels were much higher in PsO patients than those in healthy volunteers (p < .001), and posttreatment reduction was observed in five patients. However, no remarkable difference in IL‐4 level (p > .05) was found. LL‐37 level was positively correlated with IFN‐γ, IL‐17, and IL‐22 levels (p < .001) in PsO patients.

Conclusion

LL‐37 expression was significantly associated with inflammatory response, which may provide us new ideas for diagnosing and monitoring disease activity of PsO.

Capsaicin protects against septic acute liver injury by attenuation of apoptosis and mitochondrial dysfunction

Capsaicin is the main pungent bioactive constituent in red chili with promising therapeutic properties due to its anti-oxidative and anti-inflammatory effects. No evidence exists on the beneficial effect of capsaicin on apoptosis and mitochondrial function in acute liver injury (ALI) under septic conditions. For inducing septic ALI, lipopolysaccharide (LPS, 50 μg/kg) and d-galactose (D-Gal, 400 mg/kg) was intraperitoneally injected and capsaicin was given orally at 5 or 20 mg/kg. Functional markers of liver function and mitochondrial dysfunction were determined as well as hepatic assessment of apoptotic, oxidative, and inflammatory factors. Capsaicin at the higher dose appropriately decreased serum level of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in addition to reducing hepatic level of malondialdehyde (MDA), reactive oxygen species (ROS), nitrite, NF-kB, TLR4, IL-1β, TNF-α, caspase 3, DNA fragmentation and boosting sirtuin 1, Nrf2, superoxide dismutase (SOD) activity, and heme oxygenase (HO-1). These beneficial effects of capsaicin were associated with reversal and/or improvement of gene expression for pro-apoptotic Bax, anti-apoptotic Bcl2, mitochondrial and metabolic regulators PGC-1α, sirtuin 1, and AMPK, and inflammation-associated factors. Additionally, capsaicin exerted a hepatoprotective effect, as revealed by its reduction of liver histopathological changes. These findings evidently indicate hepatoprotective property of capsaicin under septic conditions that can be attributed to its down-regulation of oxidative and inflammatory processes besides its potential to attenuate mitochondrial dysfunction and apoptosis.

Combining network pharmacology, RNA-seq, and metabolomics strategies to reveal the mechanism of Cimicifugae Rhizoma - Smilax glabra Roxb herb pair for the treatment of psoriasis

BACKGROUND

Psoriasis is a prevalent chronic inflammatory skin condition marked by immune cell infiltration and keratinocyte abnormal proliferation. Cimicifugae Rhizoma - Smilax glabra Roxb (CS) herb pair, the main component of Shengma Detoxification Decoction, has been proven effective for the treatment of psoriasis. However, the mechanism is yet to be deciphered.

PURPOSE

To explore the mechanism of CS for the treatment of psoriasis.

METHODS

The imiquimod-induced psoriasis-like lesion mouse model was used to identify the targets and the molecular mechanisms of CS. Network pharmacology combined with RNA-seq strategy was employed to predict the targets and mechanisms of CS for psoriasis. Metabolomics approaches were used to demonstrate the complexity of CS for the treatment of psoriasis. Finally, a compound-response-enzyme-gene network was constructed based on the multi-omics results to elucidate potential connections.

RESULTS

The CS herb pair could significantly improve psoriatic lesions and reduce the inflammatory cell infiltration and proliferation of keratinocytes in skin lesions. Network pharmacology predicted that TNF, JNK, IL-6, and IL-1β could be potential targets. RNA-seq data revealed that CS could significantly regulate genes and signaling pathways associated with Th17 responses, such as IL-36, IL-1β, CCl2, CXCL16, keratin 14, keratin 5, and antimicrobial peptides S100A8 and S100A9 well as MAPK, mTOR, and other signaling pathways. Further experimental data validated that CS treatment remarkably reduced the expression of inflammatory cytokines and factors, such as CCL2, CCL7, IL1F6, IL-17, IL-23, IL-1β, TNF-α, and IL-6, and inhibited the phosphorylation of p38 and ERK1/2. This indicated that CS exerts its therapeutic effect by inhibiting the MAPK signaling pathways. In addition, metabolomic analyses demonstrated that CS treatment improved seven metabolic pathways, these included phenylalanine, tyrosine, pyruvate metabolism, carnitine metabolism, etc. Four key metabolites (L-Arginine, L-Phenylalanine, L-Carnitine, O-Acetylcarnitine) and nine differential genes (CMA1, PCBD2, TPSAB1, TPSB2, etc.) were identified that affected amino acid metabolism, carnitine metabolism, and other pathways contributing to the infiltration of Th17 cells in psoriatic lesions.

CONCLUSION

CS could alleviate IMQ-induced psoriasis-like dermatitis by reducing the expression of cytokines and chemokines mediated by the MAPK pathway, and improved amino acid and carnitine metabolism in vivo. Our study is the first to demonstrate the complex mechanism of CS for the treatment of psoriasis and provides a new paradigm to elucidate the pharmacological effects of Traditional Chinese Medicine (TCM) drugs for psoriasis from multiple perspectives.

Potential mechanism of oral baicalin treating psoriasis via suppressing Wnt signaling pathway and inhibiting Th17/IL-17 axis by activating PPARγ

Psoriasis (PSO), an immune-mediated chronic inflammatory skin disease, has seriously affected the quality of patients' life. It is urgent to find effective medicines with lower costs and less side effects. Baicalin (HQG) is the main bioactive substance from Scutellaria baicalensis with effects of anti-inflammation and immunoregulation. Herein, we explored the effect of oral HQG treating PSO and its potential mechanism. Firstly, network pharmacology was used to predict that HQG may act on Estrogen, TNF-alpha (tumor necrosis factor, TNF), interleukin-17 (IL-17) signaling pathways and Th17 cell differentiation, especially the key targets including TNF, Proto-oncogene tyrosine-protein kinase Src, Peroxisome proliferator-activated receptor gamma and Matrix metalloproteinase-9. Imiquimod (IMQ)-induced mice were then used to study the effects of HQG treating PSO. HQG could significantly ameliorate the skin lesions, decrease the level of inflammatory factors and inhibit Th1/Th17 cell differentiation in IMQ-induced mice. Finally, transcriptome analysis of skin lesions integrated with the prediction of network pharmacology further demonstrated that the potential mechanism may be associated with suppressing Wnt signaling pathway and inhibiting Th17/IL-17 axis by activating PPARγ. In conclusion, this study suggested that HQG may be a promising agent for further studies in the search for therapeutic strategies to treat PSO in the future.

Rosmarinic acid ameliorated psoriatic skin inflammation in mice through the novel inhibition of the interleukin-17A/interleukin-17A receptor interaction

The interaction between interleukin-17A (IL-17A) and IL-17A receptor (IL-17RA) is a crucial target of psoriasis. Several natural compounds from foods or herbs have displayed efficacies on the amelioration of psoriasis. However, the anti-psoriatic mechanisms are mostly through the common anti-inflammatory effects and rarely via the blockage of the IL-17A/IL-17RA interaction. In this study, the IL-17A/IL-17RA-targeting effects of phenylpropanoids, a large class of secondary metabolites in plants, were analyzed. By screening 17 phenylpropanoids, we found that top four compounds with IL-17A/IL-17RA-blocking abilities were rosmarinic acid, eugenol, syringic acid, and gallic acid, with inhibitory concentrations at 50% of 2.14 ± 0.35 mM, 6.35 ± 0.1 mM, 4.79 ± 0.2 mM, and >10 mM, respectively. The oral administration of rosmarinic acid ameliorated redness and scaling on the dorsal skin of imiquimod-induced psoriatic mice in a dose-dependent manner. Rosmarinic acid suppressed the production of IL-23 and IL-17A and the infiltration of granulocyte subsets in skin tissues. Docking analysis showed that rosmarinic acid docked into IL-17A/IL-17RA interaction regions and exhibited hydrogen bonding with Arg-61, Glu-68, Arg-100, and Ser-118 of IL-17A, which are located in the epitope regions recognized by IL-17A neutralizing antibodies Fab6785 and Fab6468. In conclusion, this is the first study reporting that rosmarinic acid is an IL-17A-targeting agent that ameliorates psoriatic skin inflammation in mice via blocking the IL-17A/IL-17RA interaction.

Anti-Interleukin-17 Therapy of Severe Psoriatic Patients Results in an Improvement of Serum Lipid and Inflammatory Parameters' Levels, but Has No Effect on Body Composition Parameters

BACKGROUND: Psoriasis is frequently accompanied by metabolic syndrome. Effect of anti-tumor necrosis factor therapies on increases in body weight is well-known. Data on the effects of interleukin-17 inhibitors are limited. Authors determined the effect of anti-interleukin-17 therapies on the body composition and serum lipid and inflammatory parameters among severe psoriatic patients. METHODS: Thirty-five severe psoriatic patients were enrolled. Twenty-two received secukinumab and 13 received ixekizumab as their 2nd-or 3rd-line biological treatment. Before treatment initiation and 6 months later, laboratory examinations measuring metabolic and inflammatory panels and body composition analyses were performed. RESULTS: After 6 months, a significant reduction was observed in psoriasis area severity index (p < 0.001) from 18 to 0, in c-reactive protein (p < 0.001) from 6.6 to 4.00 mg/L, in low-density lipoprotein-cholesterol (p = 0.004) from 3.69 to 3.19 mmol/L, and an improvement in high-density lipoprotein-cholesterol (p = 0.022) from 1.31 to 1.40 mmol/L. Median baseline body mass index was 32.80 kg/m². The body composition parameters did not show any significant changes. CONCLUSIONS: Anti-interleukin-17 therapy of severe psoriatic patients does not cause significant changes in body composition parameters. Improvements in the lipid and inflammatory parameters might have a beneficial effect on patients’ cardiometabolic status. This effect might be detectable in high-risk obese psoriatic patients.

Transcriptomic Analysis of the Mechanisms for Alleviating Psoriatic Dermatitis Using Taodan Granules in an Imiquimod-Induced Psoriasis-like Mouse Model

Taodan granules (TDGs) are clinically efficacious for treating psoriasis, buttheir specific mechanisms of action are unclear. In this study, we determined the concentrations of tanshinone IIA and curcumol using high-performance liquid chromatography (HPLC) to establish quality control parameters for assessing the mechanism of TDGs in treating psoriasis. Thereafter, a mouse model of psoriasis was treated with TDGs. TDGs attenuated imiquimod-induced typical erythema, scales, and thickening of the back and ear lesions in the psoriatic mouse model. Furthermore, PCNA and Ki67-positive cells were reduced in the epidermis of psoriatic lesions following TDG treatment. Finally, the sequencing results were verified using a multitude of methods, and the mechanism of action of TDGs against psoriasis was found to be via the upregulation of metabolic signaling pathways such as the Gly-Ser-Thr axis, the downregulation of immune and inflammatory pathways, and the decrease in Rac2 and Arhgdib concentrations. Overall, this study clarified the mechanism of TDG treatment for psoriasis and provided evidence for its clinical application.

Rapamycin Alleviates 2,3,7,8-Tetrachlorodibenzo-p-dioxin-Induced Aggravated Dermatitis in Mice with Imiquimod-Induced Psoriasis-Like Dermatitis by Inducing Autophagy

Recently, the mTOR signaling has emerged as an important player in the pathogenesis of psoriasis. We previously found that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced psoriatic skin inflammation was related to the inhibition of autophagy in keratinocytes. However, the effects and detailed molecular mechanisms of the mTOR inhibitor rapamycin and TCDD on psoriasis in vivo remain to be elucidated. In this study, we aimed to evaluate the effects of rapamycin and TCDD on skin lesions in imiquimod (IMQ)-induced psoriasis using a mouse model. TCDD aggravated skin inflammation in an IMQ-induced psoriatic mouse model. Furthermore, TCDD increased the expression of aryl hydrocarbon receptor (AHR), CYP1A1, proinflammatory cytokines, oxidative stress markers (NADPH oxidase (Nox) 2, Nox4), and phosphorylated P65NF-ĸB, whereas the expression of autophagy-related factors and the antioxidant marker nuclear factor-erythroid 2-related factor 2 (NRF2) decreased. Rapamycin reduced the aggravated skin inflammation induced by TCDD and restored TCDD-induced autophagy suppression and the increase of AHR expression, oxidative stress, and inflammatory response in the skin lesions of a psoriatic mouse model. In conclusion, we demonstrated that rapamycin alleviates TCDD-induced aggravated dermatitis in mice with imiquimod-induced psoriasis-like dermatitis through AHR and autophagy modulation.

Psoriatic skin inflammation induces a pre-diabetic phenotype via the endocrine actions of skin secretome

OBJECTIVE

Psoriasis is a chronic inflammatory skin disease that is thought to affect ∼2% of the global population. Psoriasis has been associated with ∼30% increased risk of developing type 2 diabetes (T2D), with numerous studies reporting that psoriasis is an independent risk-factor for T2D, separate from underlying obesity. Separately, studies of skin-specific transgenic mice have reported altered whole-body glucose homeostasis in these models. These studies imply a direct role for skin inflammation and dysfunction in mediating the onset of T2D in psoriasis patients, potentially via the endocrine effects of the skin secretome on key metabolic tissues. We used a combination of in vivo and ex vivo mouse models and ex vivo human imiquimod (IMQ) models to investigate the effects of psoriasis-mediated changes in the skin secretome on whole-body metabolic function.

METHODS

To induce psoriatic skin inflammation, mice were topically administered 75 mg of 5% IMQ cream (or Vaseline control) to a shaved dorsal region for 4 consecutive days. On day 5, mice were fasted for glucose and insulin tolerance testing, or sacrificed in the fed state with blood and tissues collected for analysis. To determine effects of the skin secretome, mouse skin was collected at day 5 from IMQ mice and cultured for 24 h. Conditioned media (CM) was collected and used 1:1 with fresh media to treat mouse explant subcutaneous adipose tissue (sAT) and isolated pancreatic islets. For human CM experiments, human skin was exposed to 5% IMQ cream for 20 min, ex vivo, to induce a psoriatic phenotype, then cultured for 24 h. CM was collected, combined 1:1 with fresh media and used to treat human sAT ex vivo. Markers of tissue inflammation and metabolic function were determined by qPCR. Beta cell function in isolated islets was measured by dynamic insulin secretion. Beta-cell proliferation was determined by measurement of Ki67 immunofluorescence histochemistry and BrDU uptake, whilst islet apoptosis was assessed by caspase 3/7 activity. All data is expressed as mean ± SEM.

RESULTS

Topical treatment with IMQ induced a psoriatic-like phenotype in mouse skin, evidenced by thickening, erythema and inflammation of the skin. Topical IMQ treatment induced inflammation and signs of metabolic dysfunction in sub-cutaneous and epidydimal adipose tissue, liver, skeletal muscle and gut tissue. However, consistent with islet compensation and a pre-diabetic phenotype, IMQ mice displayed improved glucose tolerance, increased insulin and c-peptide response to glucose, and increased beta cell proliferation. Treatment of sAT with psoriatic mouse or human skin-CM replicated the in vivo phenotype, leading to increased inflammation and metabolic dysfunction in mouse and human sAT. Treatment of pancreatic islets with psoriatic mouse skin-CM induced increases in beta-proliferation and apoptosis, thus partially replicating the in vivo phenotype.

CONCLUSIONS

Psoriasis-like skin inflammation induces a pre-diabetic phenotype, characterised by tissue inflammation and markers of metabolic dysfunction, together with islet compensation in mice. The in vivo phenotype is partially replicated by exposure of sAT and pancreatic islets to psoriatic-skin conditioned media. These results support the hypothesis that psoriatic skin inflammation, potentially via the endocrine actions of the skin secretome, may constitute a novel pathophysiological pathway mediating the development of T2D.

Role of keratinocytes and immune cells in the anti-inflammatory effects of Tripterygium wilfordii Hook. f. in a murine model of psoriasis

BACKGROUND

Tripterygium wilfordii Hook. f. (TwHf) belonging to the Celastraceae family is widely used for psoriasis treatment, especially in topical therapy in Chinese traditional medicine.

PURPOSE

In this study, we investigated the anti-psoriatic effects of topical administration of Tripterygium wilfordii Hook. f. root decoction (TwHf-RD), as well as its safety and potential mechanisms of action in vivo and in vitro.

METHODS

Psoriasis-like lesions were induced in mice using imiquimod (IMQ). The liver and kidney function and the pathological changes in the liver, kidney, and spleen were measured using ELISA and hematoxylin and eosin (H&E) staining after TwHf-RD treatment. H&E staining was used to determine the optimum concentration of TwHf-RD. The expression levels of ki67 and apoptosis related-factors in vivo and in vitro were measured by immunohistochemical staining, flow cytometry, and western blotting. Immunocyte differentiation and pro-inflammatory cytokine (IL-17A, IL-17F, IL-10, IL-22, IL-23, IFN-γ, and TNF-α) expression levels were determined by flow cytometry and RT-qPCR.

RESULTS

TwHf-RD treatment attenuated skin inflammation, inhibited keratinocyte (KC) proliferation, increased the levels of apoptosis factors, and influenced the differentiation and inflammatory response of T lymphocytes and regulatory T cells in mice. In vitro experiments proved that Tripterygium wilfordii Hook. f. root extract (TwHf-RE) regulates the proliferation and apoptosis of PAM212 cells.

CONCLUSION

TwHf-RD alleviates IMQ-induced psoriasis lesions by regulating the proliferation and apoptosis of KC and immune cells and by inhibiting immunocyte differentiation and pro-inflammatory cytokine expression.

Changes in metabolic parameters in psoriatic patients treated with secukinumab

Background:

Psoriasis is associated with cardiovascular disease and metabolic syndrome but the effects of interleukin (IL)-17A inhibitor treatment on metabolic parameters are unknown. This study aimed to determine the effects of secukinumab on metabolic parameters based on the disease activity and treatment response in patients with psoriasis.

Methods:

In this retrospective study, we included 99 patients with moderate to severe psoriasis, who received IL-17 inhibitor (secukinumab) treatment for 24 weeks between January 2016 and February 2020. The disease activity [Psoriasis Area and Severity Index (PASI)] and metabolic parameters at baseline and after 12 or 24 weeks of treatment were collected.

Results:

The PASI improved with a significant reduction of high-sensitivity C-reactive protein (hs-CRP) at weeks 12 and 24 respectively. However, body weight and body mass index were significantly increased at week 12 and 24 of treatment. Triglycerides level and atherogenic index of plasma were significantly higher in week 24 in PASI-90 non-responders. The baseline hs-CRP level and PASI-90 non-response correlated with elevated triglyceride levels.

Conclusion:

Our results suggest that obesity and hypertriglyceridemia still existed in patients despite the improved disease activity after secukinumab treatment. Higher baseline hs-CRP level and PASI-90 non-response were predictors for elevated triglyceride levels after treatment. Therefore, patient education, regular screening of the lipid profile, and weight control are recommended during the treatment of secukinumab.

Secukinumab Treatment Does Not Alter the Pharmacokinetics of the Cytochrome P450 3A4 Substrate Midazolam in Patients With Moderate to Severe Psoriasis

This open‐label disease‐drug–drug interaction study assessed whether blockade of the interleukin (IL)‐17A pathway by secukinumab and subsequent downregulation of inflammatory cytokines like IL‐6 or high‐sensitivity C‐reactive protein affects the pharmacokinetics (PKs) of a sensitive probe substrate of the cytochrome P450 3A4 isoform (CYP3A4). The PKs of midazolam, metabolized by CYP3A4, was evaluated before and after 7 and 35 days of treatment initiation of subcutaneous secukinumab at a dose of 300 mg weekly in 24 patients with moderate‐to‐severe psoriasis. Although demonstrating the expected decrease in downstream inflammatory cytokines, secukinumab had no clinically relevant effects on the PKs of midazolam, provided substantial clinical benefit, and was generally well tolerated. In summary, blockade of IL‐17A signaling in patients with moderate‐to‐severe psoriasis does not significantly affect CYP3A4 enzyme activities and, therefore, the use of secukinumab is unlikely to influence the PKs of CYP3A4 substrates.

Liver Illness and Psoriatic Patients

Psoriasis is a chronic inflammatory disease of the skin affecting approximately 2% of the world's population. Systemic treatments, including methotrexate and cyclosporin, are associated with potential hepatotoxicity, due to either direct liver damage or immunosuppression or both immunomediated and a direct liver injury; therefore, treatment of patients with psoriasis poses a therapeutic challenge. The aim of this minireview is to help clinicians in the management of psoriatic patients who develop signs of liver dysfunction. To find relevant articles, a comprehensive search was performed on PubMed, EMBASE, and Cochrane with appropriate combinations of the following keywords being considered: viral hepatitis, nonalcoholic fatty liver disease, psoriasis, hepatotoxicity, drug toxicity, cholestasis, and autoimmune liver diseases.

Activation of IL-17 receptor leads to increased oxidative inflammation in peripheral monocytes of autistic children

Millions of children are affected by different neurodevelopmental disorders, out of which autism spectrum disorder (ASD) poses a major hurdle to normal life style due to associated behavioral abnormalities. Several studies have shown an increased expression/release of Th17 related cytokine, IL-17A in ASD. IL-17A may enhance neuroinflammation via its IL-17A receptor, i.e. IL-17RA expressed in immune cells (such as monocytes) of autistic children. Increased oxidative stress has been implicated in a number of neuropsychiatric disorders including ASD. However, whether IL-17A/IL-17RA signaling contributes to oxidative inflammation in monocytes of autistic children has not been explored previously. With this background, we performed this study in peripheral monocytes of ASD patients and age-matched typically developing children. Our study shows that ASD individuals have increased IL-17RA expression in monocytes which is associated with increased nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway and inducible nitric oxide synthase (iNOS)/nitrotyrosine expression as compared to typically developing children. Moreover, in vitro activation of IL-17 receptor by IL-17A in monocytes isolated from ASD individuals leads to enhanced iNOS expression via NFκB pathway. IL-17RA antibody treatment in vitro reversed IL-17A-induced increase in NFκB and iNOS/nitrotyrosine expression in monocytes isolated from ASD subjects. These data connect increased IL-17A/IL-17RA signaling in ASD patients with enhanced oxidative inflammation in monocytes. Therefore, IL-17 receptor signaling in monocytes may potentiate the effects of IL-17A released by other immune cells and may aggravate neuroinflammation in ASD. Our study further suggests that blockade of IL-17A/IL-17 receptor signaling may be beneficial in the children with ASD.

The Systemic Response to Topical Aldara Treatment is Mediated Through Direct TLR7 Stimulation as Imiquimod Enters the Circulation

Topical application of Aldara cream, containing the Toll-like receptor 7/8 agonist Imiquimod, is a widely used mouse model for investigating the pathogenesis of psoriasis. We have previously used this model to study the effects of peripheral inflammation on the brain, and reported a brain-specific response characterised by increased transcription, infiltration of immune cells and anhedonic-like behavior. Here, we perform a more robust characterisation of the systemic response to Aldara application and find a potent but transient response in the periphery, followed by a prolonged response in the brain. Mass spectrometry analysis of plasma and brain samples identified significant levels of Imiquimod in both compartments at molar concentrations likely to evoke a biological response. Indeed, the association of Imiquimod with the brain correlated with increased Iba1 and GFAP staining, indicative of microglia and astrocyte reactivity. These results highlight the potency of this model and raise the question of how useful it is for interpreting the systemic response in psoriasis-like skin inflammation. In addition, the potential impact on the brain should be considered with regards to human use and may explain why fatigue, headaches and nervousness have been reported as side effects following prolonged Aldara use.

Immunity and Fibrogenesis: The Role of Th17/IL-17 Axis in HBV and HCV-induced Chronic Hepatitis and Progression to Cirrhosis

Cirrhosis is a common final pathway for most chronic liver diseases; representing an increasing burden worldwide and is associated with increased morbidity and mortality. Current evidence has shown that, after an initial injury, the immune response has a significant participation in the ongoing damage, and progression from chronic viral hepatitis (CVH) to cirrhosis, driving the activation and maintenance of main fibrogenic pathways. Among immune deregulations, those related to the subtype 17 of T helper lymphocytes (Th17)/interleukin-17 (IL-17) axis have been recognized as key immunopathological and prognostic elements in patients with CVH. The Th17/IL-17 axis has been found involved in several points of fibrogenesis chain from the activation of stellate cells, increased expression of profibrotic factors as TGF-β, promotion of the myofibroblastic or epithelial–mesenchymal transition, stimulation of the synthesis of collagen, and induction of imbalance between matrix metalloproteinases and tissue inhibitors of metalloproteinases (TIMPs). It also promotes the recruitment of inflammatory cells and increases the expression of proinflammatory cytokines such as IL-6 and IL-23. So, the Th17/IL-17 axis is simultaneously the fuel and the flame of a sustained proinflammatory and profibrotic environment. This work aims to present the immunopathologic and prognostic role of the Th17/IL-17 axis and related pathways in fibrogenesis and progression to cirrhosis in patients with liver disease due to hepatitis B virus (HBV) and hepatitis C virus (HCV).

IL-17A causes depression-like symptoms via NFκB and p38MAPK signaling pathways in mice: Implications for psoriasis associated depression

Psoriasis has been shown to be associated with an increased prevalence of comorbid major depression. IL-17A plays an important role in both depression and psoriasis. IL-17A has been shown to be elevated in systemic circulation of psoriatic patients. IL-17A released from different immune cells during psoriasis may be responsible for the development of neuropsychiatric symptoms associated with depression. Therefore, this study explored the association of systemic IL-17A with depression. The present study utilized imiquimod model of psoriatic inflammation as well as IL-17A administration in mice to investigate the effect of IL-17A on depression-like behavior. Psoriatic inflammation led to enhanced IL-17A expression in peripheral immune cells of both innate and adaptive origin. This was associated with increased NFκB/p38MAPK signaling and inflammatory mediators in different brain regions, and depression-like symptoms (as reflected by sucrose preference and tail suspension tests). The role of IL-17A was further confirmed by administering it alone for ten days, followed by assessment of the same parameters. IL-17A administration produced effects similar to psoriasis-like inflammation on neurobehavior and NFκB/p38MAPK pathways. Moreover, both NFκB and p38MAPK inhibitors led to attenuation in IL-17A associated with depression-like behavior via reduction in inflammatory mediators, such as MCP-1, iNOS, IL-6, and CXCL-2. Furthermore, anti-IL17A antibody also led to a reduction in imiquimod-induced depression-like symptoms, as well as NFκB/p38MAPK signaling. The present study shows that IL-17A plays an important role in comorbid depression associated with psoriatic inflammation, where both NFκB and p38MAPK pathways play significant roles via upregulation of inflammatory mediators in the brain.

Imiquimod induced ApoE-deficient mice might be a composite animal model for the study of psoriasis and dyslipideamia comorbidity

BACKGROUND

Psoriasis patients are at increased risk of developing lipid metabolism disturbances. Both psoriasis and dyslipideamia not only closely interact in disease development, but occur as mutual side effects in some medicine treatment. The interactive mechanism of the two diseases is complicated and still unclear.

OBJECTIVE

Here, we proposed applying imiquimod on the dorsal skin of ApoE^-/- mice to establish a composite animal model which formed psoriasiform skin lesions under hyperlipidemic condition.

METHOD

By comparison with corresponding wild-type(C57BL/6) mice, the composite mice model was evaluated by skin pathological features, lipid levels, immune inflammatory factors in order to clarify the diseases interplay mechanism. In addition, IL-17 mAb treatment was applied to observe the effect of IL-17 antibody on the composite animal model.

RESULTS

The results verified that imiquimod-induced ApoE^-/- mice model presented keratinocyte hyperplasia, parakeratosis, inflammatory cells infiltration and elevated serum lipid levels, and also reflected the complex interaction between inflammation and lipid metabolism. IL-17 mAb could inhibit psoriasis skin lesions with lipid accumulation via STAT3 pathway, but no influence on elevated serum cholesterol.

CONCLUSIONS

Imiquimod-induced ApoE^-/- mice model presented the pathological features of psoriasis and dyslipideamia, which could be an ideal composite animal model for the study of pathogenesis and pharmacotherapeutics of psoriasis and dyslipideamia comorbidity.