Soluble IL-6R-mediated IL-6 trans-signaling activation contributes to the pathological development of psoriasis

Cytokines in psoriasis: From pathogenesis to targeted therapy

Psoriasis is a multifactorial disease that affects 0.84% of the global population and it can be associated with disabling comorbidities. As patients present with thick scaly lesions, psoriasis was long believed to be a disorder of keratinocytes. Psoriasis is now understood to be the outcome of the interaction between immunological and environmental factors in individuals with genetic predisposition. While it was initially thought to be solely mediated by cytokines of type-1 immunity, namely interferon-γ, interleukin-2, and interleukin-12 because it responds very well to cyclosporine, a reversible IL-2 inhibitor; the discovery of Th-17 cells advanced the understanding of the disease and helped the development of biological therapy. This article aims to provide a comprehensive review of the role of cytokines in psoriasis, highlighting areas of controversy and identifying the connection between cytokine imbalance and disease manifestations. It also presents the approved targeted treatments for psoriasis and those currently under investigation.

The skin circadian clock gene F3 as a potential marker for psoriasis severity and its bidirectional relationship with IL-17 signaling in keratinocytes

OBJECTIVE

Psoriasis is an immune-mediated skin disease where the IL-17 signaling pathway plays a crucial role in its development. Chronic circadian rhythm disorder in psoriasis pathogenesis is gaining more attention. The relationship between IL and 17 signaling pathway and skin clock genes remains poorly understood.

METHODS

GSE121212 with psoriatic lesion and healthy controls was used as the exploration cohort for searching analysis. Datasets GSE54456, GSE13355, GSE14905, GSE117239, GSE51440, and GSE137218 were applied to validation analysis. Single-cell RNA sequencing (scRNA-seq) dataset GSE173706 was used to explore the F3 expression and related pathway activities in single-cell levels. Through intersecting with high-expression DEGs, F3 was selected as the signature skin circadian gene in psoriasis for further investigation. Functional analyses, including correlation analyses, prediction of transcription factors, protein-protein interaction, and single gene GSEA to explore the potential roles of F3. ssGSEA algorithm was performed to uncover the immune-related characteristics of psoriasis. We further explored F3 expression in the specific cell population in scRNA-seq dataset, besides this, AUCell analysis was performed to explore the pathway activities and the results were further compared between the specific cell cluster. Immunohistochemistry experiment, RT-qPCR was used to validate the location and expression of F3, small interfering RNA (siRNA) transfection experiment in HaCaT, and transcriptome sequencing analysis were applied to explore the potential function of F3.

RESULTS

F3 was significantly down-regulated in psoriasis and interacted with IL-17 signaling pathway. Low expression of F3 could upregulate the receptor of JAK-STAT signaling, thereby promoting keratinocyte inflammation.

CONCLUSION

Our research revealed a bidirectional link between the skin circadian gene F3 and the IL-17 signaling pathway in psoriasis, suggesting that F3 may interact with the IL-17 pathway by activating JAK-STAT within keratinocytes and inducing abnormal intracellular inflammation.

A genome-wide cross-trait analysis identifies shared loci and causal relationships of obesity and lipidemic traits with psoriasis

Background

Obesity and dyslipidemia, major global health concerns, have been linked to psoriasis, but previous studies faced methodological limitations and their shared genetic basis remains unclear. This study examines various obesity-related and lipidemic traits as potential contributors to psoriasis development, aiming to clarify their genetic associations and potential causal links.

Methods

Summary statistics from genome-wide association studies (GWAS) conducted for obesity-related traits (body mass index (BMI), waist-to-hip ratio (WHR), and waist-to-hip ratio adjusted for the body mass index (WHRadjBMI)) and lipidemic traits (high-density lipoprotein (HDL), LDL, triglyceride (TG), total Cholesterol (TC), apolipoprotein A1 (apoA1), apolipoprotein B (apoB), and apolipoprotein E (apoE)) and psoriasis, all in populations of European ancestry, were used. We quantified genetic correlations, identified shared loci and explored causal relationship across traits.

Results

We found positive genetic correlation between BMI and psoriasis (rg=0.22, p=2.44×10-18), and between WHR and psoriasis (rg=0.19, p=1.41×10-12). We further found the positive genetic correlation between psoriasis and WHRadjBMI(rg=0.07, p=1.81×10-2) the genetic correlation, in while the effect of BMI was controlled for. We identified 14 shared loci underlying psoriasis and obesity-related traits and 43 shared loci between psoriasis and lipidemic traits via cross-trait meta-analysis. Mendelian randomization (MR) supported the causal roles of BMI (IVW OR=1.483, 95%CI=1.333-1.649), WHR (IVW OR=1.393, 95%CI=1.207-1.608) and WHRadjBMI (IVW OR=1.18, 95%CI=1.047-1.329) in psoriasis, but not observe any significant association between lipidemic traits and the risk of psoriasis. Genetic predisposition to psoriasis did not appear to affect the risk of obesity and lipidemic traits.

Conclusions

An intrinsic link between obesity-related traits and psoriasis has been demonstrated. The genetic correlation and causal role of obesity-related traits in psoriasis highlight the significance of weight management in both the prevention and treatment of this condition.

Interleukins and Psoriasis

Psoriasis is an immune-mediated chronic inflammatory skin disease that affects 2% to 3% of the world's population. It is widely assumed that immune cells and cytokines acting together play a crucial part in the pathophysiology of psoriasis by promoting the excessive proliferation of skin keratinocytes and inflammatory infiltration. Interleukins (ILs), as a critical component of cytokines, have been closely associated with the pathogenesis and progression of psoriasis. This review summarizes the current contribution of ILs to psoriasis and describes the role each IL performs in psoriasis. Furthermore, the paper presents the therapeutic effects and application prospects of biologics developed for ILs in clinical treatment and experiments. The study aims to further the research on ILs in the treatment of psoriasis.

Elevated serum IL-6 levels predict treatment interruption in patients with moderate to severe psoriasis: a 6-year real-world cohort study

BACKGROUND

Real-world, primary data on the treatment of psoriasis are scarce, especially concerning the role of soluble biomarkers as outcome predictors.

OBJECTIVE

The authors evaluated the utility of Th1/Th17 serum cytokines along with clinical characteristics as predictors of drug survival in the treatment of psoriasis.

METHODS

The authors consecutively included participants with moderate to severe psoriasis who were followed up for 6 years. Baseline interferon-α, tumor necrosis factor-α, and interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17A were measured using a cytometric bead array; clinical data were assessed. The authors calculated hazard ratios (HRs) for drug survival using a Cox proportional hazards model.

RESULTS

The authors included 262 patients, most of whom used systemic immunosuppressants or biologics. In the multivariate model, poor quality of life measured by the Dermatology Life Quality Index (HR = 1.04; 95% CI 1.01‒1.07; p = 0.012) and elevated baseline IL-6 (HR = 1.99; 95% CI 1.29‒3.08; p = 0.002) were associated with treatment interruption.

STUDY LIMITATIONS

The main limitation of any cohort study is the presence of confounders that could not be detected in clinical evaluation.

CONCLUSIONS

Poor quality of life and elevated baseline serum IL-6 level predicted treatment interruption in patients with moderate to severe psoriasis. Although IL-6 is not the most important mediator of the inflammatory pathway in the skin environment, it is an interesting biomarker candidate for predicting psoriasis treatment response.

Pigment epithelium-derived factor (PEDF) represses the glucose transporter 1 (GLUT1) mRNA expression and may be a potential therapeutic agent in psoriasis: a case-control and experimental study

We investigated the whole blood GLUT1 mRNA expression and serum pigment epithelium-derived factor (PEDF), interleukin-6 (IL-6), fetuin-A, and pentraxin-3 (PTX3) levels in psoriatic patients and tested their correlations with the severity of psoriasis using the psoriasis area and severity index (PASI) score. Also, we tested the GLUT1 mRNA expression after an in vitro treatment of human skin fibroblast (HSF) cell lines with PEDF. The case-control part of the study recruited 74 participants (44 psoriatic patients and 30 healthy volunteers). Whole blood GLUT1 mRNA fold changes were estimated by RT-PCR, and serum PEDF, IL-6, fetuin-A, and PTX3 levels were measured by ELISA kits. In the experimental part, the HSF cell lines were treated with different concentrations of PEDF for different times to test its effect on the GLUT1 mRNA expression. The whole blood GLUT 1 expression significantly increased in psoriatic patients and correlated positively with serum IL-6, fetuin-A, PTX3 levels and with the severity of psoriasis while negatively with serum PEDF levels. The PEDF-treated HSF cell lines showed a time- and dose-dependent decline in the GLUT 1 mRNA expression. The whole blood GLUT 1 mRNA is a non-invasive biomarker that is associated with the severity of psoriasis. PEDF represses GLUT 1 expression and may be a potential therapeutic agent in psoriasis.Trial registration: ClinicalTrials.gov Identifier: NCT04242082.

Pro-inflammatory cytokine IL-6 regulates LMO4 expression in psoriatic keratinocytes via AKT/STAT3 pathway

The transcription factor LIM-only protein 4 (LMO4) is overexpressed in the psoriatic epidermis and regulates keratinocyte proliferation and differentiation. High LMO4 expression levels are induced by interleukin-23 (IL-23) to activate the AKT/STAT3 signaling pathway. Interleukin-6 (IL-6) is mainly involved in regulating T cell functions and development in patients with psoriasis. However, whether LMO4 expression is regulated by IL-6 remains unclear. Therefore, the purpose of this study is to explore the role and molecular mechanisms of IL-6 in regulating LMO4 expression. The interleukin-6 (IL-6) levels in human plasma were determined using a chemiluminescence immunoassay system. A psoriasis-like mouse model was established using imiquimod induction. Epidermal keratinocytes (HaCaT) were cultured in defined keratinocyte-serum-free medium and stimulated by IL-6 alone or with inhibitors. The proteins of interest were detected using western blot analysis, immunofluorescence, and immunohistochemistry. The 5-ethynyl-2'-deoxyuridine assay was used to detect cell proliferation. The results revealed that IL-6 levels were markedly increased in the plasma of patients with psoriasis, compared to healthy control. The high expression of LMO4 was consistent with high levels of IL-6, p-AKT, and p-STAT3 in the lesions of both psoriasis patients and imiquimod-induced psoriasis-like mice. IL-6 activates the AKT/STAT3 signaling pathway, followed by LMO4 high-expression in HaCaT cells. IL-6 induces HaCaT proliferation and differentiation via AKT/STAT3 signaling pathway activation. We think that the high expression of LMO4 in psoriatic keratinocytes requires IL-6 to activate the AKT/STAT3 signaling pathway and leads to epidermal keratinocytes abnormal proliferation and differentiation.

Protein inhibitor of activated STAT3 (PIAS3) attenuates psoriasis and associated inflammation

Psoriasis is a common chronic inflammatory multisystem disease accompanied by hyperproliferation and inflammation of epidermal keratinocytes. Signal transducer and activator of transcription 3 (STAT3) is constitutively activated and plays an important role in epidermal keratinocytes of human psoriatic skin lesions. In this study, we investigated the effects of an endogenous STAT3 inhibitor, a protein inhibitor of activated STAT3 (PIAS3), on the proliferation and inflammation of psoriatic cells. The expression of PIAS3 in psoriatic tissues and healthy skin was analyzed using the Gene Expression Omnibus database and clinical samples. The human immortalized epidermal (HaCaT) cells were used to establish an in vitro psoriasis-like cell model. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-thethrazolium (MTS) assay was used to detect cell proliferation. Flow cytometry was used to determine apoptosis levels. Real-time PCR, western blotting, and enzyme-linked immunosorbent assay (ELISA) were used to detect the expression levels of related factors. Furthermore, a mouse model of imiquimod (IMQ)-induced psoriatic dermatitis was established to verify the in vitro experimental results. The results showed that the mRNA and protein expression levels of PIAS3 were lower in psoriatic lesions than in normal tissues. PIAS3 inhibited the proliferation and promoted apoptosis of M5-induced HaCaT cells. Simultaneously, the mRNA and protein expression levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), and keratin 17 (K17) were significantly decreased and that of p53 was increased, thereby inhibiting the inflammatory response and promoting apoptosis. PIAS3 inhibited the transcription activity of STAT3 and noncanonical nuclear factor-kappaB (NF-κB). Furthermore, PIAS3 attenuated IMQ-induced psoriasis-like inflammation in mice. Our findings suggest that PIAS3 plays an important role in psoriasis by regulating the STAT3/NF-κB signaling pathway and p53. The lack of PIAS3 may represent a novel mechanism underlying the pathogenesis of psoriasis.

Nano transdermal system combining mitochondria-targeting cerium oxide nanoparticles with all-trans retinoic acid for psoriasis

Psoriasis is an inflammatory skin disease that is intricately linked to oxidative stress. Antioxidation and inhibition of abnormal proliferation of keratinocytes are pivotal strategies for psoriasis. Delivering drugs with these effects to the site of skin lesions is a challenge that needs to be solved. Herein, we reported a nanotransdermal delivery system composed of all-trans retinoic acid (TRA), triphenylphosphine (TPP)-modified cerium oxide (CeO2) nanoparticles, flexible nanoliposomes and gels (TCeO2-TRA-FNL-Gel). The results revealed that TCeO2 synthesized by the anti-micelle method, with a size of approximately 5 nm, possessed excellent mitochondrial targeting ability and valence conversion capability related to scavenging reactive oxygen species (ROS). TCeO2-TRA-FNL prepared by the film dispersion method, with a size of approximately 70 nm, showed high drug encapsulation efficiency (>96%). TCeO2-TRA-FNL-Gel further showed sustained drug release behaviors, great transdermal permeation ability, and greater skin retention than the free TRA. The results of in vitro EGF-induced and H2O2-induced models suggested that TCeO2-TRA-FNL effectively reduced the level of inflammation and alleviated oxidative stress in HaCat cells. The results of in vivo imiquimod (IMQ)-induced model indicated that TCeO2-TRA-FNL-Gel could greatly alleviate the psoriasis symptoms. In summary, the transdermal drug delivery system designed in this study has shown excellent therapeutic effects on psoriasis and is prospective for the safe and accurate therapy of psoriasis.

Cytokine status and significant increase of IL-6 and sIL-6R in the aqueous humor of diabetic cataract patients revealed by quantitative multiplexed assays

OBJECTIVE

This study aimed to investigate inflammatory cytokine expression profiles in the aqueous humor (AH) of diabetic cataract (DC) patients.

METHODS

A quantitative multiplexed antibody assay was performed to measure the expression levels of 40 inflammatory cytokines in AH samples from DC and age-related cataract (ARC) patients. Bioinformatics analysis was used to examine the functions of the cytokines. Enzyme-linked immunosorbent assays (ELISAs) and western blots were performed to verify the data.

RESULTS

The multiplexed antibody assay revealed that the expression levels of IL-6, sIL-6R, IL-17A, IL-8, MCP-1, TNF-β, RANTES, TIMP-1, and TIMP-2 were higher in the AH of DC patients compared with ARC patients. However, IL-1ra and IL-1a expression levels were lower in the DC patient AH samples. Pathway analysis indicated that IL-6 and sIL-6R belong to the class I helical cytokine family, which is associated with many biological functions. ELISA and western blot results confirmed that IL-6R and IL-6 expression levels were significantly higher in DC patients compared with ARC patients.

CONCLUSIONS

Our results revealed the status of 40 inflammatory cytokines in the AH by quantitative multiplexed assays. Additionally, IL-6 and sIL-6R were expressed markedly higher in DC compared with ARC, which may play critical roles in DC pathophysiology.

Extracellular CIRP Upregulates Proinflammatory Cytokine Expression via the NF-kappaB and ERK1/2 Signaling Pathways in Psoriatic Keratinocytes

Psoriasis is a chronic inflammatory skin disease, and elevation of proinflammatory cytokine levels is a critical driver of the pathogenesis of psoriasis. Extracellular cold-inducible RNA-binding protein (eCIRP) has been shown to play a role in various acute and chronic inflammatory diseases. C23, a short peptide derived from CIRP, competitively binds CIRP receptors and reduces damage in inflammatory diseases. However, the effect of eCIRP in psoriasis has not been studied. In the present study, we investigated the role of eCIRP in the expression of proinflammatory cytokines in keratinocytes. Our data show that eCIRP expression was increased in the sera of psoriasis patients and imiquimod- (IMQ-) induced psoriatic mice and cells stimulated with proinflammatory cytokines (IL-1α, IL-17A, IL-22, oncostatin M, and TNF-α; mix M5). Recombinant human CIRP (rhCIRP) promoted the expression of the proinflammatory cytokines TNF-α, IL-6, and IL-8 and the activation of NF-kappaB (NF-κB) and ERK1/2 in cultured keratinocytes. We then found that the above effects of eCIRP could be blocked by C23 in both normal keratinocytes and M5-stimulated psoriatic keratinocytes. In addition, in vivo experiments revealed that C23 could effectively ameliorate IMQ-induced psoriatic dermatitis. TNF-α and IL-6 mRNA expressions were reduced in the skin lesions of mice with C23-treated IMQ-induced psoriasis, and this effect was accompanied by inhibition of the NF-κB and ERK1/2 signaling pathways. In summary, eCIRP plays an important role in the pathogenesis of psoriasis and may become a new target for psoriasis treatment.

Sarilumab Administration in COVID-19 Patients: Literature Review and Considerations

Two years have passed since WHO declared a pandemic state for SARS-CoV-2 infection. COVID-19 pathogenesis consists of a first viral phase responsible for early symptoms followed by an inflammatory phase, cytokine-mediated, responsible for late-onset manifestations up to ARDS. The dysregulated immune response has an outstanding role in the progression of pulmonary damage in COVID-19. IL-6, through the induction of pro-inflammatory chemokines and cytokines, plays a key role in the development and maintenance of inflammation, acting as a pioneer of the hyperinflammatory condition and cytokine storm in severe COVID-19. Therefore, drugs targeting both IL-6 and IL-6 receptors have been evaluated in order to blunt the abnormal SARS-CoV-2-induced cytokine release. Sarilumab, a high-affinity anti-IL-6 receptor antibody, may represent a promising weapon to treat the fearsome hyperinflammatory phase by improving the outcome of patients with moderate-to-severe COVID-19 pneumonia. Further prospective and well-designed clinical studies with larger sample sizes and long-term follow-up are needed to assess the efficacy and the safety of this therapeutic approach to achieve improved outcomes in COVID-19.

Psoriasis: An Immunogenetic Perspective

Psoriasis is an erythematous-squamous dermatosis with a polygenic inheritance history. Both environmental and genetic factors play a role in the etiology of the disease. Over the past two decades, numerous linkage analyzes and genome-wide association studies have been conducted to investigate the role of genetic variation in disease pathogenesis and progression. To date, >70 psoriasis susceptibility loci have been identified, including HLA-Cw6, IL12B, IL23R, and LCE3B/3C. Some genetic markers are used in clinical diagnosis, prognosis, treatment, and personalized new drug development that can further explain the pathogenesis of psoriasis. This review summarizes the immunological mechanisms involved in the etiopathogenesis of psoriasis and recent advances in susceptibility genes and highlights new potential targets for therapeutic intervention.

Preparation, Characterization and Evaluation of the Anti-Inflammatory Activity of Epichlorohydrin-β-Cyclodextrin/Curcumin Binary Systems Embedded in a Pluronic®/Hyaluronate Hydrogel

Curcumin (Cur) is an anti-inflammatory polyphenol that can be complexed with polymeric cyclodextrin (CD) to improve solubility and bioavailability. The aim of the present work was to prepare a CurCD hydrogel to treat inflammatory skin conditions. Epichlorohydrin-β-CD (EpiβCD) was used as polymeric CD. To characterize the binary system, solid-state and in-solution studies were performed. Afterwards, an experimental design was performed to optimize the hydrogel system. Finally, the CurEpiβCD hydrogel system was tested for anti-inflammatory activity using a HaCat psoriasis cell model. Co-grinded Cur/EpiβCD binary system showed a strong interaction and Curcumin solubility was much improved. Its combination with Pluronic® F-127/hyaluronate hydrogel demonstrated an improvement in release rate and Curcumin permeation. After testing its anti-inflammatory activity, the system showed a significant reduction in IL-6 levels. Hydrogel-containing CurEpiβCD complex is a great alternative to treat topical inflammatory diseases.