Signs of innate immune activation and premature immunosenescence in psoriasis patients

Topical application of a BCL-2 inhibitor ameliorates imiquimod-induced psoriasiform dermatitis by eliminating senescent cells

BACKGROUND

Psoriasis is an inflammatory skin disease with unclear pathogenesis and unmet therapeutic needs.

OBJECTIVE

To investigate the role of senescent CD4+ T cells in psoriatic lesion formation and explore the application of senolytics in treating psoriasis.

METHODS

We explored the expression levels of p16INK4a and p21, classical markers of cellular senescence, in CD4+ T cells from human psoriatic lesions and imiquimod (IMQ)-induced psoriatic lesions. We prepared a senolytic gel using B-cell lymphoma 2 (BCL-2) inhibitor ABT-737 and evaluated its therapeutic efficacy in treating psoriasis.

RESULTS

Using multispectrum immunohistochemistry (mIHC) staining, we detected increased expression levels of p16INK4a and p21 in CD4+ T cells from psoriatic lesions. After topical application of ABT-737 gel, significant alleviation of IMQ-induced psoriatic lesions was observed, with milder pathological alterations. Mechanistically, ABT-737 gel significantly decreased the percentage of senescent cells, expression of T cell receptor (TCR) α and β chains, and expression of Tet methylcytosine dioxygenase 2 (Tet2) in IMQ-induced psoriatic lesions, as determined by mIHC, high-throughput sequencing of the TCR repertoire, and RT-qPCR, respectively. Furthermore, the severity of psoriatic lesions in CD4creTet2f/f mice was milder than that in Tet2f/f mice in the IMQ-induced psoriasis model.

CONCLUSION

We revealed the roles of senescent CD4+ T cells in developing psoriasis and highlighted the therapeutic potential of topical ABT-737 gel in treating psoriasis through the elimination of senescent cells, modulation of the TCR αβ repertoire, and regulation of the TET2-Th17 cell pathway.

The potential for senotherapy as a novel approach to extend life quality in veterinary medicine

Cellular senescence, a condition where cells undergo arrest and can assume an inflammatory phenotype, has been associated with initiation and perpetuation of inflammation driving multiple disease processes in rodent models and humans. Senescent cells secrete inflammatory cytokines, proteins, and matrix metalloproteinases, termed the senescence associated secretory phenotype (SASP), which accelerates the aging processes. In preclinical models, drug interventions termed "senotherapeutics" selectively clear senescent cells and represent a promising strategy to prevent or treat multiple age-related conditions in humans and veterinary species. In this review, we summarize the current available literature describing in vitro evidence for senotheraputic activity, preclinical models of disease, ongoing human clinical trials, and potential clinical applications in veterinary medicine. These promising data to date provide further justification for future studies identifying the most active senotherapeutic combinations, dosages, and routes of administration for use in veterinary medicine.

Eomes-dependent mitochondrial regulation promotes survival of pathogenic CD4+ T cells during inflammation

The mechanisms whereby Eomes controls tissue accumulation of T cells and strengthens inflammation remain ill-defined. Here, we show that Eomes deletion in antigen-specific CD4+ T cells is sufficient to protect against central nervous system (CNS) inflammation. While Eomes is dispensable for the initial priming of CD4+ T cells, it is required for long-term maintenance of CNS-infiltrating CD4+ T cells. We reveal that the impact of Eomes on effector CD4+ T cell longevity is associated with sustained expression of multiple genes involved in mitochondrial organization and functions. Accordingly, epigenetic studies demonstrate that Eomes supports mitochondrial function by direct binding to either metabolism-associated genes or mitochondrial transcriptional modulators. Besides, the significance of these findings was confirmed in CD4+ T cells from healthy donors and multiple sclerosis patients. Together, our data reveal a new mechanism by which Eomes promotes severity and chronicity of inflammation via the enhancement of CD4+ T cell mitochondrial functions and resistance to stress-induced cell death.

Characterization of the TCRβ repertoire of peripheral MR1-restricted MAIT cells in psoriasis vulgaris patients

Psoriasis vulgaris (PV) is an inflammatory skin disease largely driven by aberrant αβT cells. Mucosal-associated invariant T (MAIT) cells, which constitute the largest circulating innate-like αβT cell community in human adults, are characterized by a semi-invariant TCRVα7.2 receptor and MR1-restricted affinity toward microbial metabolites. Limited MAIT TCRα diversity is complemented by a more variable TCRβ repertoire, but its footprint in the MAIT repertoire of PV patients has never been tested. Here, we used bulk TCRSeq, MiXCR, VDJTools, and Immunarch pipelines to decipher and compare TCRβ clonotypes from flow-sorted, peripheral TCRVα7.2+MR1-5-OP-RU-tet+MAIT cells from 10 PV patients and 10 healthy, matched controls. The resulting TCRβ collections were highly private and individually unique, with small public clonotype content and high CDR3β amino acid length variability in both groups. The age-related increase in the 'hyperexpanded' clonotype compartment was observed in PV, but not in healthy MAIT repertoires. The TCRβ repertoires of PV patients were also marked by skewed TRBV/TRBJ pairing, and the emergence of PV-specific, public CDR3β peptide sequences closely matching the published CDR3β record from psoriatic skin. Overall, our study provides preliminary insight into the peripheral MAIT TCRβ repertoire in psoriasis and warrants further evaluation of its diagnostic and clinical significance.

A 2-week time-restricted feeding attenuates psoriasis-like lesions with reduced inflammatory cytokines and immunosenescence in mice

Psoriasis, a well-established T-cell mediated dermatosis, exhibits a robust correlation with obesity and systemic inflammation, manifesting psoriasis skin lesions and premature immunosenescence within the peripheral blood and lesion. Intermittent fasting (IF) has exhibited various beneficial effects in reducing inflammation, resisting oxidative stress and slowing ageing, as well as losing weight. A form of IF known as time-restricted feeding (TRF) restricts daily caloric intake within 4-8 h. Nonetheless, the advantageous impacts of TRF on psoriasis still require further verification. We measured the acanthosis in Imiquimod (IMQ)-induced psoriasis mice and evaluated their pathological phenotypes. Our study examined the effects of a 2-week TRF on body weight and metabolic parameters. The subsets of T cells in spleens and skin lesions were accessed by flow cytometry. Cytokines and senescence-associated genes were evaluated by immunofluorescence and RT-qPCR. RNA sequencing was conducted on skin lesions. According to our findings, a 2-week TRF attenuates psoriasis-like lesions in mice with reduced inflammatory cytokines and mitigated immunosenescence. TRF increased the counts of CD4+ Treg cells in skin lesions while reducing the counts of Th2 and Th17 cells in spleens. Furthermore, the administration of TRF resulted in a decrease in the population of CD4+ senescent T cells in both the dermis and spleens, concomitant with the expression of senescence-associated genes in spleen CD4+ T cells. The outcomes mentioned above provide valuable evidence in support of TRF for the management of psoriasis.

Associations of A20, CYLD, Cezanne and JAK2 Genes and Immunophenotype with Psoriasis Susceptibility

Background and Objectives: Psoriasis is an immune-mediated chronic inflammatory skin disorder and commonly associated with highly noticeable erythematous, thickened and scaly plaques. Deubiquitinase genes, such as tumor necrosis factor-alpha protein 3 (TNFAIP3, A20), the cylindromatosis (CYLD) and Cezanne, function as negative regulators of inflammatory response through the Janus kinase/signal transducers and activators of transcription (JAK-STAT) pathways. In this study, polymorphisms and expressions of A20, CYLD and Cezanne genes as well as immunophenotype in psoriatic patients were determined. Materials and Methods: In total, 82 patients with psoriasis and 147 healthy individuals with well-characterized clinical profiles were enrolled. Gene polymorphisms were determined by direct DNA sequencing, gene expression profile by quantitative real time-polymerase chain reaction (PCR), immunophenotype by flow cytometry, and the secretion of cytokines and cancer antigen (CA) 125 by enzyme-linked Immunosorbent assay (ELISA). Results: The inactivation of A20, CYLD and Cezanne and increased levels of TNF-α, IFN-γ and CA 125 was observed in psoriatic patients. Importantly, patients with low A20 expression had significant elevations of triglyceride and total cholesterol concentrations and higher numbers of CD13+CD117- and CD19+CD23+ (activated B) cells than those with high A20 expression. Genetic analysis indicated that all rs4495487 SNPs in the JAK2 gene, rs200878487 SNPs in the A20 gene and four SNPs (c.1584-375, c.1584-374, rs1230581026 and p.W433R) in the Cezanne gene were associated with significant risks, while the rs10974947 variant in the JAK2 gene was at reduced risk of psoriasis. Moreover, in the Cezanne gene, p.W433R was predicted to be probably damaging by the Polyphen-2 prediction tool and an AA/CC haplotype was associated with a high risk of psoriasis. In addition, patients with higher CA 125 levels than the clinical cutoff 35 U/mL showed increased levels of IFN-γ than those with normal CA 125 levels. Conclusions: A20 expression was associated with lipid metabolism and the recruitment of CD13+ CD117- and activated B cells into circulation in psoriatic patients. Besides this, the deleterious effect of the p.W433R variant in the Cezanne gene may contribute to the risk of psoriasis.

Potential roles of inflammasomes in the pathophysiology of Psoriasis: A comprehensive review

Psoriasis is an inflammatory skin disease whose pathophysiology is attributed to both innate and adaptive immune cells and molecules. Despite the crucial roles of the immune system in psoriasis, it cannot be categorized as an autoimmune disease because of the lack of main signs of autoimmunity, such as specific antibodies, well-defined antigens, and autoimmune genetic risk factors. The presence of some cellular and molecular properties, such as the presence of neutrophils in skin lesions and the activation of the innate immune system, attributes psoriasis to a group of diseases called autoinflammatory disorders. Autoinflammatory diseases refer to a group of inherited disorders whose main manifestations are recurrent fever, a high level of acute-phase reactant, and a tendency for inflammation of the skin, joints, and other organs like the nervous system. In most autoinflammatory disorders, it has been seen that complexes of the high-molecular-weight protein named inflammasomes have significant roles. The inflammasome complex usually is formed and activated in the stimulated immune cell cytoplasm, and its activation consequently leads to inflammatory events such as producing of active caspase-1, mature interleukin-1β (IL-1β), and IL-18 and can cause an inflammatory programmed cell death called pyroptosis. Since the identification of inflammasomes, it has been shown that there are close links between them and hereditary and acquired autoinflammatory diseases like psoriasis. In this review, we aim to focus on well-defined inflammasome and their role in the pathophysiology of psoriasis.

Immunosenescence and Skin: A State of Art of Its Etiopathogenetic Role and Crucial Watershed for Systemic Implications

Immunosenescence is a complex multifactorial phenomenon consisting of wide-ranging remodeling of the immune system during the life span, resulting in an age-related qualitative-quantitative decline of immune cells and cytokines. A growing body of evidence in the international literature is highlighting the etiopathogenetic role of skin immunosenescence in the onset of various dermatologic conditions. Skin immunosenescence also serves as an interesting watershed for the onset of system-wide conditions in the context of allergic inflammation. Moreover, in recent years, an increasingly emerging and fascinating etiopathogenetic parallelism has been observed between some mechanisms of immunosenescence, both at cutaneous and systemic sites. This would help to explain the occurrence of apparently unconnected comorbidities. Throughout our review, we aim to shed light on emerging immunosenescent mechanisms shared between dermatologic disorders and other organ-specific diseases in the context of a more extensive discussion on the etiopathogenetic role of skin immunosenescence. A promising future perspective would be to focus on better understanding the mutual influence between skin and host immunity, as well as the influence of high inter-individual variability on immunosenescence/inflammaging. This can lead to a more comprehensive "immunobiographic" definition of each individual.

Cornus officinalis Seed Extract Inhibits AIM2-Inflammasome Activation and Attenuates Imiquimod-Induced Psoriasis-like Skin Inflammation

The AIM2 inflammasome is an innate immune system component that defends against cytosolic bacteria and DNA viruses, but its aberrant activation can lead to the progression of various inflammatory diseases, including psoriasis. However, there have been few reports of specific inhibitors of AIM2 inflammasome activation. In this study, we aimed to investigate the inhibitory activity of ethanolic extracts of seeds of Cornus officinalis (CO), a herb and food plant used in traditional medicine, on AIM2-inflammasome activation. We found that CO inhibited the release of IL-1β induced by dsDNA in both BMDMs and HaCaT cells, but that it showed no effect on the release of IL-1β induced by NLRP3 inflammasome triggers, such as nigericin and silica, or the NLRC4 inflammasome trigger flagellin. Furthermore, we demonstrated that CO inhibited the cleavage of caspase-1, an inflammasome activation marker, and an upstream event, the translocation and speck formation of ASC. In addition, further experiments and mechanistic investigations revealed that CO can inhibit AIM2 speck formation induced by dsDNA in AIM2-overexpressing HEK293T cells. To verify the correlation in vivo, we investigated the efficacy of CO in an imiquimod (IMQ)-induced psoriasis model, which has reported associations with the AIM2 inflammasome. We found that topical application of CO alleviated psoriasis-like symptoms, such as erythema, scaling, and epidermal thickening, in a dose-dependent manner. Moreover, CO also significantly decreased IMQ-induced expression of AIM2 inflammasome components, including AIM2, ASC, and caspase-1, and led to the elevation of serum IL-17A. In conclusion, our results suggest that CO may be a valuable candidate for the discovery of AIM2 inhibitors and the regulation of AIM2-related diseases.

Assessment of soluble skin surface protein levels for monitoring psoriasis vulgaris in adult psoriasis patients using non-invasive transdermal analysis patch: A pilot study

To improve the care of patients with chronic inflammatory skin conditions, such as psoriasis, there is a need for diagnostic methods that can facilitate personalized medicine. This exploratory pilot study aimed to determine whether non-invasive measurements of inflammation-related proteins from psoriatic skin can be sampled using the FibroTx Transdermal Analysis Patch (TAP) to assess disease severity and monitor pharmacodynamic changes. Ten healthy volunteers and 44 psoriasis vulgaris patients were enrolled in the exploratory pilot study. Skin surface protein measurements for healthy and lesional skin were performed using TAP. Patients' scores of psoriasis activity and severity (PASI) were documented, and differences in the thickness of skin layers were determined using sonography. The study assessed the skin surface protein levels of psoriasis patients undergoing whole-body treatment with narrow-band UVB to evaluate whether the levels of the skin surface proteins IL-1α, IL-1RA CXCL-1/2, and hBD-1 were associated with the disease activity and severity measurements. Using TAP technology, it was observed that there were clear differences in levels of IL-1α, IL-1RA, CXCL-1/2, and hBD-1 between psoriasis lesional and non-lesional skin. In addition, a positive correlation between CXCL-1/2 and desquamation, and between CXCL-1/2 and SLEB thickness was observed. During UVB treatment, the TAP measurements revealed a clear reduction of IL-1RA, CXCL 1/2, and hBD-1 on lesional skin. Further, skin surface measurements of IL-1RA and CXCL-1/2 displayed a different profile than those achieved by visual scoring of local inflammation, thus indicating that measuring the 'molecular root' of inflammation appears to have value as an objective, non-invasive biomarker measurement for scoring disease severity.

Roles of AIM2 Gene and AIM2 Inflammasome in the Pathogenesis and Treatment of Psoriasis

Psoriasis is an immune-mediated chronic inflammatory skin disease caused by a combination of environmental incentives, polygenic genetic control, and immune regulation. The inflammation-related gene absent in melanoma 2 (AIM2) was identified as a susceptibility gene for psoriasis. AIM2 inflammasome formed from the combination of AIM2, PYD-linked apoptosis-associated speck-like protein (ASC) and Caspase-1 promotes the maturation and release of inflammatory cytokines such as IL-1β and IL-18, and triggers an inflammatory response. Studies showed the genetic and epigenetic associations between AIM2 gene and psoriasis. AIM2 gene has an essential role in the occurrence and development of psoriasis, and the inhibitors of AIM2 inflammasome will be new therapeutic targets for psoriasis. In this review, we summarized the roles of the AIM2 gene and AIM2 inflammasome in pathogenesis and treatment of psoriasis, hopefully providing a better understanding and new insight into the roles of AIM2 gene and AIM2 inflammasome in psoriasis.

An integrative analysis to reveal that CLEC2B and ferroptosis may bridge the gap between psoriatic arthritis and cancer development

Patients with cutaneous psoriasis (PsC) and psoriatic arthritis (PsA) are reported with increased cancer risk, but the underlying mechanism is less clear, especially the association between the presence of PsA and cancer risk. Motivated by the role of ferroptosis in the progression of cancers as well as inflammation response in psoriasis, this experiment attempts to investigate the relationship between ferroptosis regulators and hub genes in PsA by bioinformatic analysis. The findings revealed an exclusive correlation between CISD1 (ferroptosis regulator) and CLEC2B (hub gene) in PsA group as well as multiple cancer types. Furthermore, CLEC2B was discovered differentially expressed in a variety of cancers and is closely associated with immune cell infiltration as well as immune checkpoints. These results indicate that ferroptosis may act as a bridge between psoriatic arthritis and the onset of certain malignancies.

Endogenous Retroviruses (ERVs): Does RLR (RIG-I-Like Receptors)-MAVS Pathway Directly Control Senescence and Aging as a Consequence of ERV De-Repression?

Bi-directional transcription of Human Endogenous Retroviruses (hERVs) is a common feature of autoimmunity, neurodegeneration and cancer. Higher rates of cancer incidence, neurodegeneration and autoimmunity but a lower prevalence of autoimmune diseases characterize elderly people. Although the re-expression of hERVs is commonly observed in different cellular models of senescence as a result of the loss of their epigenetic transcriptional silencing, the hERVs modulation during aging is more complex, with a peak of activation in the sixties and a decline in the nineties. What is clearly accepted, instead, is the impact of the re-activation of dormant hERV on the maintenance of stemness and tissue self-renewing properties. An innate cellular immunity system, based on the RLR-MAVS circuit, controls the degradation of dsRNAs arising from the transcription of hERV elements, similarly to what happens for the accumulation of cytoplasmic DNA leading to the activation of cGAS/STING pathway. While agonists and inhibitors of the cGAS-STING pathway are considered promising immunomodulatory molecules, the effect of the RLR-MAVS pathway on innate immunity is still largely based on correlations and not on causality. Here we review the most recent evidence regarding the activation of MDA5-RIG1-MAVS pathway as a result of hERV de-repression during aging, immunosenescence, cancer and autoimmunity. We will also deal with the epigenetic mechanisms controlling hERV repression and with the strategies that can be adopted to modulate hERV expression in a therapeutic perspective. Finally, we will discuss if the RLR-MAVS signalling pathway actively modulates physiological and pathological conditions or if it is passively activated by them.

CCL27 is a crucial regulator of immune homeostasis of the skin and mucosal tissues

Abundant immune cells reside in barrier tissues. Understanding the regulation of these cells can yield insights on their roles in tissue homeostasis and inflammation. Here, we report that the chemokine CCL27 is critical for establishment of resident lymphocytes and immune homeostasis in barrier tissues. CCL27 expression is associated with normal skin and hair follicle development independent of commensal bacterial stimulation, indicative of a homeostatic role for the chemokine. Accordingly, in the skin of CCL27-knockout mice, there is a reduced presence and dysregulated localization of T cells that express CCR10, the cognate receptor to CCL27. Besides, CCL27-knockout mice have overreactive skin inflammatory responses in an imiquimod-induced model of psoriasis. Beyond the skin, CCL27-knockout mice have increased infiltration of CCR10⁺ T cells into lungs and reproductive tracts, the latter of which also exhibit spontaneous inflammation. Our findings demonstrate that CCL27 is critical for immune homeostasis across barrier tissues.

Microbiome and Human Aging: Probiotic and Prebiotic Potentials in Longevity, Skin Health and Cellular Senescence

The role of the microbiome in human aging is important: the microbiome directly impacts aging through the gastrointestinal system. However, the microbial impact on skin has yet to be fully understood. For example, cellular senescence is an intrinsic aging process that has been recently associated with microbial imbalance. With age, cells become senescent in response to stress wherein they undergo irreversible growth arrest while maintaining high metabolic activity. An accumulation of senescent cells has been linked to various aging and chronic pathologies due to an overexpression of the senescence-associated secretory phenotype (SASP) comprised of proinflammatory cytokines, chemokines, growth factors, proteases, lipids and extracellular matrix components. In particular, dermatological disorders may be promoted by senescence as the skin is a common site of accumulation. The gut microbiota influences cellular senescence and skin disruption through the gut-skin axis and secretion of microbial metabolites. Metabolomics can be used to identify and quantify metabolites involved in senescence. Moreover, novel anti-senescent therapeutics are warranted given the poor safety profiles of current pharmaceutical drugs. Probiotics and prebiotics may be effective alternatives, considering the relationship between the microbiome and healthy aging. However, further research on gut composition under a senescent status is needed to develop immunomodulatory therapies.

The STING antagonist H-151 ameliorates psoriasis via suppression of STING/NF-κB-mediated inflammation

BACKGROUND AND PURPOSE

Psoriasis is a chronic inflammatory skin disease associated with both innate and adaptive immune responses. The stimulator of interferon genes (STING) protein engages in sensing of cytosolic DNA to initiate dsDNA-driven immune responses. In vitro and in vivo anti-psoriasis effects of STING antagonist H-151 were explored.

EXPERIMENTAL APPROACH

We analysed the gene expression profile of STING and related downstream targets in the skin samples of healthy people and psoriasis patients from the GEO database. Cellular inhibitory activity of H-151 on STING pathway was confirmed via qPCR and western blotting. The preventive effect of topical application of H-151 on imiquimod-induced psoriatic mice was examined through histological, immunohistochemical, immunofluorescent, flow cytometric analysis, ELISA Kits and other approaches. Preliminary mechanistic studies were also performed.

KEY RESULTS

Gene expressions of STING and its downstream target were up-regulated in lesional skin samples from psoriasis patients. Topical administration of H-151 attenuated the skin lesions in imiquimod-induced psoriatic mouse model, while the secretion of pro-inflammatory cytokines (IL-17, IL-23 and IL-6), infiltration of M1 macrophages and differentiation of Th17 cells were significantly suppressed by H-151 treatment. Mechanistically, H-151 inhibited STING/NF-κB signalling in both keratinocytes and immune cells.

CONCLUSION AND IMPLICATIONS

H-151 displayed anti-inflammatory activity in both keratinocytes and immune cells, and decreased the severity of psoriatic response in vivo. Inhibition of STING signalling pathway may represent a novel therapeutic approach to psoriasis and related complications.

An evaluation of the recognised systemic inflammatory biomarkers of chronic sub-optimal inflammation provides evidence for inflammageing (IFA) during multiple sclerosis (MS)

The pathogenesis of the human demyelinating disorder multiple sclerosis (MS) involves the loss of immune tolerance to self-neuroantigens. A deterioration in immune tolerance is linked to inherent immune ageing, or immunosenescence (ISC). Previous work by the author has confirmed the presence of ISC during MS. Moreover, evidence verified a prematurely aged immune system that may change the frequency and profile of MS through an altered decline in immune tolerance. Immune ageing is closely linked to a chronic systemic sub-optimal inflammation, termed inflammageing (IFA), which disrupts the efficiency of immune tolerance by varying the dynamics of ISC that includes accelerated changes to the immune system over time. Therefore, a shifting deterioration in immunological tolerance may evolve during MS through adversely-scheduled effects of IFA on ISC. However, there is, to date, no collective proof of ongoing IFA during MS. The Review addresses the constraint and provides a systematic critique of compelling evidence, through appraisal of IFA-related biomarker studies, to support the occurrence of a sub-optimal inflammation during MS. The findings justify further work to unequivocally demonstrate IFA in MS and provide additional insight into the complex pathology and developing epidemiology of the disease.

Broad proteomic screen reveals shared serum proteomic signature in patients with psoriatic arthritis and psoriasis without arthritis

OBJECTIVE

To identify novel serum proteins involved in the pathogenesis of PsA as compared with healthy controls, psoriasis (Pso) and AS, and to explore which proteins best correlated to major clinical features of the disease.

METHODS

A high-throughput serum biomarker platform (Olink) was used to assess the level of 951 unique proteins in serum of patients with PsA (n = 20), Pso (n = 18) and AS (n = 19), as well as healthy controls (HC, n = 20). Pso and PsA were matched for Psoriasis Area and Severity Index (PASI) and other clinical parameters.

RESULTS

We found 68 differentially expressed proteins (DEPs) in PsA as compared with HC. Of those DEPs, 48 proteins (71%) were also dysregulated in Pso and/or AS. Strikingly, there were no DEPs when comparing PsA with Pso directly. On the contrary, hierarchical cluster analysis and multidimensional scaling revealed that HC clustered distinctly from all patients, and that PsA and Pso grouped together. The number of swollen joints had the strongest positive correlation to ICAM-1 (r = 0.81, P < 0.001) and CCL18 (0.76, P < 0.001). PASI score was best correlated to PI3 (r = 0.54, P < 0.001) and IL-17 receptor A (r = -0.51, P < 0.01). There were more proteins correlated to PASI score when analysing Pso and PsA patients separately, as compared with analysing Pso and PsA patients pooled together.

CONCLUSION

PsA and Pso patients share a serum proteomic signature, which supports the concept of a single psoriatic spectrum of disease. Future studies should target skin and synovial tissues to uncover differences in local factors driving arthritis development in Pso.

Psoriasis-associated impairment of CCL27/CCR10-derived regulation leads to IL-17A/IL-22-producing skin T-cell overactivation

Psoriasis-associated suppression of the skin-specific chemokine/receptor CCL27/CCR10 axis leads to enhanced pathogenic IL-17A/IL-22-producing skin T cell activation and inflammation.

Second-Strand Synthesis-Based Massively Parallel scRNA-Seq Reveals Cellular States and Molecular Features of Human Inflammatory Skin Pathologies

High-throughput single-cell RNA-sequencing (scRNA-seq) methodologies enable characterization of complex biological samples by increasing the number of cells that can be profiled contemporaneously. Nevertheless, these approaches recover less information per cell than low-throughput strategies. To accurately report the expression of key phenotypic features of cells, scRNA-seq platforms are needed that are both high fidelity and high throughput. To address this need, we created Seq-Well S3 ("Second-Strand Synthesis"), a massively parallel scRNA-seq protocol that uses a randomly primed second-strand synthesis to recover complementary DNA (cDNA) molecules that were successfully reverse transcribed but to which a second oligonucleotide handle, necessary for subsequent whole transcriptome amplification, was not appended due to inefficient template switching. Seq-Well S3 increased the efficiency of transcript capture and gene detection compared with that of previous iterations by up to 10- and 5-fold, respectively. We used Seq-Well S3 to chart the transcriptional landscape of five human inflammatory skin diseases, thus providing a resource for the further study of human skin inflammation.

Current knowledge on autoantigens and autoantibodies in psoriasis

In the past decades, clinical and experimental evidence has demonstrated that psoriasis is an immune-mediated inflammatory disease of the skin that occurs in genetically susceptible individuals. Psoriasis also shows clear autoimmune pathomechanisms, but specific cellular targets for the onset and maintenance of psoriatic lesions were not established until 2014. Since then, four psoriasis autoantigens were discovered, namely cathelicidin LL-37, melanocytic ADAMTSL5, lipid antigen PLA2G4D and keratin 17. Autoreactive T cells against these autoantigens were found in a number of patients with moderate-to-severe plaque psoriasis. Moreover, the discovery of autoantibodies against LL-37 and ADAMTSL5 and their strong association with psoriatic arthritis (PsA) suggest a potential role of these autoantibodies in the pathogenesis of PsA. This review discusses the current studies on psoriatic autoantigens and the associated circulating autoantibodies and their mechanisms involved in the development and maintenance of psoriatic plaques. Recent autoimmune evidence fuelled the discussion on psoriasis as an autoimmune skin disorder and has the potential to develop new treatment strategies with protective and therapeutic antigen-targeted methods.

IL-22 Paucity in APECED Is Associated With Mucosal and Microbial Alterations in Oral Cavity

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is caused by recessive mutations in the AIRE gene. The hallmark of the disease is the production of highly neutralizing autoantibodies against type I interferons and IL-22. Considering the importance of IL-22 in maintaining mucosal barrier integrity and shaping its microbial community, we sought to study potential changes in the oral cavity in this model of human IL-22 paucity. We found that besides known Th22 cell deficiency, APECED patients have significantly fewer circulating MAIT cells with potential IL-22 secreting capacity. Saliva samples from APECED patients revealed local inflammation, the presence of autoantibodies against IFN-α and IL-22, and alterations in the oral microbiota. Moreover, gene expression data of buccal biopsy samples suggested impaired antimicrobial response and cell proliferation, both of which are processes regulated by IL-22. Our data complement the knowledge gained from mouse models and support the concept of IL-22 being a critical homeostatic cytokine in human mucosal sites.

Psoriasis and Metabolic Syndrome: Comorbidities and Environmental and Therapeutic Implications

Psoriasis (PS) is an incessant, fiery skin sickness characterized by erythematous plaques with thick silvery scales, white or red patches of the skin, which encompasses several immunological, biomolecular, genetic, and environmental factors that may lead to further development of metabolic syndrome (MS) and vice versa. Metabolic syndrome is composed of multiple components (high blood pressure, abdominal obesity, glucose intolerance, and dyslipidemia) of risk factors that arise primarily from insulin resistance, mostly mediated by inflammatory cytokines, such as tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6) together with leptin and adiponectin, which are molecules also found in PS. The incidence, severity, and poor prognosis of the psoriatic diseases could be influenced by cardiometabolic diseases, which are controllable or preventable with intense lifestyle modification such as diet, exercise, and weight control. We performed a far-reaching writing search of different databases as part of this review; 47 investigations were regarded as important based on our search. Fasting, proper weight management, and special diet modifications seemed to have a positive impact on the management of PS. This review agrees with previous literature that nutritionists and specialists of preventive medicine should play a central role in the evaluation and management of psoriatic patients. We recommended that the management of this disease should focus on the environmental factors first instead of the genetic and immunologic pathways.

EFLA 945 restricts AIM2 inflammasome activation by preventing DNA entry for psoriasis treatment

Psoriasis is a chronic inflammatory skin disease that affects about 2% of the general population. Activation of the Absent in Melanoma 2 (AIM2) inflammasome is crucial for immune defense, but it can also cause inflammatory and autoimmune diseases, including psoriasis. We currently lack an AIM2 inflammasome inhibitor that could be used therapeutically. Here, we show that EFLA 945, a safe product of red grape vine leaf extracts, can restrict AIM2 inflammasome activation. Mechanistically, EFLA945 prevents DNA entry into THP-1-derived macrophages, and thereby inhibits cytoplasmic DNA-dependent apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, caspase-1 activation, and the secretion of interleukin (IL)-1β and IL-18. The major phytochemicals of EFLA 945, resveratrol and peonidin 3-O-glucoside (P3G), appear to be the potential bioactive compounds responsible for its ability to restrict AIM2-dependent IL-1β secretion. Importantly, in an in vivo mouse model, EFLA 945 attenuates imiquimod (IMQ)-induced psoriasis-related pro-inflammatory responses in topical psoriatic skin, including caspase-1 activation, IL-1β maturation, and IL-17 production, and decreases the severity of psoriasis. Together, these results demonstrate that the safe natural product, EFLA 945, can restrict the AIM2 inflammasome activation through preventing DNA entry and may prove beneficial for treating psoriasis.

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

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

Interleukin-6 in juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is a chronic childhood arthritis. Its pathogenesis is very complicated, with the involvement of not only immune cells but various types of parenchymal cells, and is affected by both genetic and environmental predispositions. The clinical spectrum from inflammation to related conditions is largely mediated by cytokines including interleukin (IL)-6. Fluctuations in IL-6 and its related molecules can modulate the pathogenesis and the clinical presentation positively or negatively. The recent clinical impact of IL-6 blockade on JIA has begun a therapeutic paradigm shift. This review describes the characteristics of JIA, mainly focused on IL-6 with the current therapeutic perspective.

Association Study of the Caspase Gene Family and Psoriasis Vulgaris Susceptibility in Northeastern China

Background

Abnormal apoptosis of keratinocytes is one of the pathological changes of psoriasis. Caspases (CASPs) are the central engines of apoptosis. Studies to date have shown that some SNPs alter the expression of related genes and lead to changes in disease risk. However, no studies have investigated the associations between gene polymorphisms and the risk of psoriasis in Han population in northeast China. Therefore, we conducted a case-control study to explore this question in Han population of northeastern China.

Methods

540 patients with PsV and 612 healthy age- and sex-matched controls were enrolled in this study. We determined the genotypes of 17 single nucleotide polymorphisms (SNPs) from 11 genes of caspase family by the improved multiplex ligation detection reaction (iMLDR) method. A model-based single SNP frequentist test and haplotype association studies were performed to evaluate the association between SNPs and PsV.

Results

In the single SNP tests, rs6704688 in CASP8 was significantly associated with psoriasis vulgaris (PsV) in Han population of northeastern China (P = 0.0169, P' = 0.0179 under the additive model; P = 0.0126, P' = 0.0149 under the heterozygous model). In haplotype analyses, the CASP7 haplotype GC was found to be associated with PsV risk (case group versus control group, 47.2% versus 54.4%, respectively, p = 0.0149).

Conclusions

Our study presented that the gene polymorphisms of CASP7 and CASP8 were significantly associated with PsV in Han population of northeastern China, which implied the functional relationship between PsV and caspase genes. CASP8 and CASP7 SNPs could be new potential biomarkers for risk stratification and prevention of PsV.

Bystander T Cells: A Balancing Act of Friends and Foes

T cell responses are essential for appropriate protection against pathogens. T cell immunity is achieved through the ability to discriminate between foreign and self-molecules, and this relies heavily on stringent T cell receptor (TCR) specificity. Recently, bystander activated T lymphocytes, that are specific for unrelated epitopes during an antigen-specific response, have been implicated in diverse diseases. Numerous infection models have challenged the classic dogma of T cell activation as being solely dependent on TCR and major histocompatibility complex (MHC) interactions, indicating an unappreciated role for pathogen-associated receptors on T cells. We discuss here the specific roles of bystander activated T cells in pathogenesis, shedding light on the ability of these cells to modulate disease severity independently from TCR recognition.

Increased senescent CD8+ T cells in the peripheral blood mononuclear cells of Behçet's disease patients

Behçet's disease (BD) is a chronic inflammatory disease characterized by recurrent mucocutaneous, ocular, and skin lesions. Immunosenescence is associated with increased susceptibility to infection and chronic low grade inflammation. This study aimed to investigate the differences in the frequencies of immunosenescent cells in the peripheral blood mononuclear cells (PBMCs) of patients with BD. PBMCs were isolated from age-matched patients with active BD (n = 19), inactive BD (n = 20), disease controls (DCs, n = 15) and healthy controls (HCs, n = 15). The frequencies of senescent CD4+ T cells (CD3+ CD4+ CD27- CD28- cells), CD8+ T cells (CD3+ CD8+ CD27- CD28- cells) and B cells (CD19+ CD27- IgD- cells) were analyzed using flow cytometry. Senescence-associated β galactosidase activity was also measured in CD8+ T cells using flow cytometry with 5-dodecanoylaminofluorescein di-β-D-galactopyranoside. Frequencies of senescent CD4+ and CD19+ cells were not significantly different between the groups. The frequency of senescent CD8+ T cells was significantly higher in active BD than in DCs and HCs. C-reactive protein and erythrocyte sedimentation rate levels, which indicate disease activity, did not correlate with increased frequencies of immunosenescent cells. Steroid treatment, specific organ involvement, and HLA-B51 status did not have a significant influence on the frequencies of immunosenescent cells. Frequencies of senescence-associated β galactosidase+ CD8+ T cells were significantly higher in active BD and inactive BD compared to DCs and HCs. There was an increased frequency of senescent CD8+ T cells in the PBMCs of patients with BD.