Platelets: Underestimated Regulators of Autoinflammation in Psoriasis

Cathelicidin-HG alleviates psoriasis by targeting glycoprotein VI to inhibit platelet-neutrophil complexes formation

Psoriasis, a chronic inflammatory skin disorder, is characterized by a complex interplay among immune cells. Although the specific mechanisms of platelet involvement in psoriasis are not fully elucidated, platelet activation is considered a major pathogenic factor. In this study, we investigated the role of Cathelicidin-HG (Cath-HG), a peptide derived from Hylarana guentheri skin that exhibits potent inhibitory activity against platelet glycoprotein VI (GPVI), in an imiquimod-induced psoriasis mouse model. Our experimental findings demonstrated that Cath-HG significantly alleviates psoriasis symptoms, reduces platelet-neutrophil complexes (PNCs) formation, and attenuates neutrophil activation at lesion sites. In vitro studies confirmed that Cath-HG inhibits collagen-induced platelet activation via GPVI, thereby disrupting PNCs formation and suppressing subsequent inflammatory responses. These findings not only establish GPVI as a key regulator of PNC-mediated inflammation in psoriasis but also identify Cath-HG as a promising therapeutic candidate. This study provides a novel mechanistic insight into platelet-neutrophil interactions in psoriasis and highlights the potential of GPVI as a therapeutic target for innovative psoriasis treatments.

Association of systemic immune-inflammation index (SII) with risk of psoriasis: a cross-sectional analysis of National Health and Nutrition Examination Survey 2011-2014

BACKGROUND

The systemic immune-inflammation index (SII) is an emerging marker of inflammation, and the onset of psoriasis is associated with inflammation. The aim of our study was to investigate the potential impact of SII on the incidence rate of adult psoriasis.

METHODS

We conducted a cross-sectional study based on the National Health and Nutrition Examination Survey (NHANES) 2011-2014 data sets. Multiple logistic regression analyses with appropriate covariates adjustment were the major methods in this study. Subgroup analyses were conducted by age, gender, race, smoking status, alcohol consumption, history of heart attack, stroke, coronary heart disease and diabetes. Interactions among these variables were also detected. We further utilized smooth curve fitting to explore potential nonlinear associations between SII and psoriasis across different subgroups. The receiver operating characteristic curve analysis was used to assess the diagnostic value of SII for psoriasis in the general population and diabetic individuals. Multiple imputation was adopted as sensitivity analysis to address potential bias due to missing data.

RESULTS

9314 participants (≥ 20 years) were included. A significant positive association was observed between SII and psoriasis (OR = 1.56; P = 0.0069). Subgroup analysis revealed significant positive association in males (OR = 1.52; P = 0.0288), females (OR = 1.61; P = 0.0322), Non-Hispanic Whites (OR = 1.55; P = 0.0190), people aged 40-59 years (OR = 1.98; P = 0.0386), diabetics (OR = 3.40; P = 0.0088), and overweight participants (OR = 1.80; P = 0.0034). SII had a higher predictive value for psoriasis in diabetic patients (AUC = 0.62; 95% CI [0.55, 0.70]). In stroke patients, SII was negatively correlated with the occurrence of psoriasis, and interaction test suggested the effect of SII on psoriasis was significantly modified by stroke (P = 0.0003). Nonlinear relationships between SII and psoriasis were observed in participants aged 20 to 39, former smokers, current drinkers, individuals with or without heart attack, those without coronary heart disease, and overweight participants.

CONCLUSIONS

SII was positively associated with psoriasis. Testing for SII levels may help to identify the onset of psoriasis early.

Impact of inflammatory skin conditions on the biological profile of plasma rich in growth factor

Plasma rich in growth factors (PRGF) can be used over patients suffering from dermatoses due to its anti-inflammatory effect. However, this population group might present soluble autoimmune components and there is limited information about the effect of chronic skin inflammation on PRGF bioactive properties. With the aim of characterizing PRGF composition, PRGF from healthy (H) donors and patients with atopic dermatitis (AD), psoriasis (PS), or lichen sclerosus (LS) was obtained. In order to reduce the inflammatory component, leukocyte exclusion and heat-inactivation (Immunosafe) were tested. Haematological-serological parameters, platelet functionality, clot microstructure, protein content and bioactivity were determined. Mean values and 95 % confidence intervals (mean[95 % CI]) were computed for key haematological parameters, such as platelet (410×103/mm3[371-449]) and leukocyte content (205×103/mm3[148-262]), platelet activation (resting: 4.3 %[3.1-5.5] and activated: 97.4 %[96.7-98.0]), the concentration of plasma proteins and morphogens, including immunoglobulins A (210.7 mg/dL[191.8-229.6]), G (933.1 mg/dL[887.2-978.9]), E (783.5 mg/dL[54.4-1512.6]), and M (115.0 mg/dL[97.1-133.0]), Complement Protein (31.6 mg/mL[26.6-36.6]), C-Reactive protein (3.1 mg/L[2.0-4.1]), TGF-β1 (35975.6 pg/mL[34221.3-37729.8]), fibronectin (146410.0 ng/mL[136518.3-156301.7]), PDGF-AB (13308.5 pg/mL[12401.0-14216.0]), CD40L (2389.3 pg/mL[1887.7-2890.8]), IL-4 (0.12 pg/mL[0.07-0.18]), IL-13 (35.4 pg/mL[21.0-49.7]), IL-1β (0.09 pg/mL[0.06-0.11]) and TNF-α (0.31 pg/mL[0.24-0.38]), and also for cell proliferation (332.9ngDNA/mL[317.4-348.3]), viability (135.6 %[132.0-139.2]) and migration (103.8cells/mm2[98.3-109.3]). Plasma from AD donors presented increased Immunoglobulin E (IgE) that was significantly reduced after Immunosafe along with the complement system and autoantibodies. Platelet functionality was altered for AD, but no microstructure differences were identified. Pathological groups presented reduced concentration of fibronectin (AD/LS) and Platelet-Derived Growth Factor (PDGF-AB) (P). Immunosafe treatment reduced Cluster of Differentiation 40 Protein (CD40L), interleukin 1β (IL-1β), and Tumor Necrosis Factor α (TNF-α) concentrations. Fibroblasts supplemented with PRGF obtained from pathological patients (PS/AD) showed reduced viability but Immunosafe increased cell proliferation and migration in SP (LS) and L-SP samples (PS/AD). In conclusion, PRGF derived from pathological patients present autoimmune components, but heat-inactivation or leukocyte exclusion could minimize local side effects.

Associations of novel complete blood count-derived inflammatory markers with psoriasis: a systematic review and meta-analysis

Psoriasis is an immune-mediated disorder which primarily affects skin and has systemic inflammatory involvement. Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), and monocyte-to-lymphocyte ratio (MLR) are novel complete blood count (CBC)-derived markers which can reflect systemic inflammation. This study aimed to systematically investigate the associations of NLR, PLR, SII, and MLR with psoriasis. This study was performed in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. A comprehensive search of Pubmed, Embase, Scopus, and Google Scholar was conducted for relevant studies. Observational studies evaluating the correlations of NLR, PLR, SII, or MLR with psoriasis were included. The primary outcomes were the associations of these inflammatory markers with the presence and severity of psoriasis. The random-effect model was applied for meta-analysis. 36 studies comprising 4794 psoriasis patients and 55,121 individuals in total were included in the meta-analysis. All inflammatory markers were significantly increased in psoriasis groups compared to healthy controls (NLR: MD = 0.59, 95% CI: 0.47-0.7; PLR: MD = 15.53, 95% CI: 8.48-22.58; SII: MD = 111.58, 95% CI: 61.49-161.68; MLR: MD = 0.034, 95% CI: 0.021-0.048; all p < 0.001). Between-group mean differences in NLR and PLR were positively correlated with the mean scores of Psoriasis Area Severity Index (NLR: p = 0.041; PLR: p = 0.021). NLR, PLR, SII, and MLR are associated with the presence of psoriasis. NLR and PLR serve as significant indicators of psoriasis severity. These novel CBC-derived markers constitute potential targets in the screening and monitoring of psoriasis.

Association between systemic immune-inflammation index and psoriasis: a population-based study

Background

The systemic immune-inflammation index (SII),as measured by lymphocyte, neutrophil and platelet counts in peripheral blood, is regarded as a favorable indicator of both inflammatory state and immune response. Psoriasis is an immune-mediated disease notable for its chronic inflammation of the entire system. Our research sought to explore the latent link between psoriasis and SII.

Methods

We performed a cross-sectional investigation utilizing data extracted from the National Health and Nutrition Examination Survey (NHANES, 2009-2014). Employing multivariate linear regression models and subgroup analysis, we sought to uncover the association between SII and psoriasis.

Results

This study enrolled a total of 17,913 participants as part of its research cohort. Our multivariate linear regression analysis revealed a notable and positive correlation between SII and psoriasis [1.013 (1.000, 1.026)]. As SII tertiles increased, the risk of psoriasis demonstrated an upward trend. The significant dependence on this positive association were maintained in women, BMI(≥ 30 kg/m2),non-stroke and non-cancer subjects in subgroup analysis and interaction tests. Furthermore, we identified a significant association between SII and psoriasis, characterized by two consecutive inverted U-shaped patterns. Notably, the analysis revealed the most prominent inflection point at a specific value of 797.067.

Conclusions

The results indicate a significant correlation between elevated SII levels and the presence of psoriasis. However, to corroborate and strengthen these results, additional large-scale prospective studies are required.

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

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

Disease-specific corona mediated co-delivery of MTX and siRNA-TNFα by a polypeptide nanoplatform with antigen-scavenging functions in psoriasis

Psoriatic self-antigen LL37 has the ability to stimulate skin-homing T lymphocytes, which is the constitutive factor for the relapse of psoriasis. The local inflammatory modulation in psoriatic skin is not sufficient for the restoration of immune homeostasis. In this study, we found the expression levels of disease specific proteins including LL37, S100A8 and S100A9 were significantly increased in psoriasis. The self-assembled nanoparticles based on methoxy-poly(ethylene glycol)-block-poly(L-histidine) and methoxy-poly(ethylene glycol)-block-poly(L-lactic acid) (HLNPs) were capable of interacting and absorbing these disease specific proteins, leading to the accumulation of HLNPs in peripheral inflammatory immune cells. Therefore, we proposed an "Antigen-scavenging" polypeptide nano-system assembled from the "sandwich" structure composed of HLNPs, siRNA-TNFα, and oligolysine conjugated methotrexate prodrug (HLNP-MNs), with the encapsulation of ROS-responsive methotrexate prodrug and siRNA-TNFα. We evaluated the biological fate of HLNP-MNs in vivo, the ROS-responsive release of methotrexate (MTX) and siRNA-TNFα in inflammatory immune cells, the suppression of immune response triggered by autoantigen LL37 and the inhibition of skin-homing T lymphocytes from the aspects of "nanoparticle-protein" interaction, cellular level and mouse models. The design of "Antigen-scavenging" polypeptide nanoparticles with loading of MTX and siRNA-TNFα, can shed light on restoring immune homeostasis in psoriasis.

Assessment of microvesicles from different cell origins in patients with psoriasis: evidence of thrombogenic, proinflammatory microenvironment in the absence of established cardiovascular disease

Psoriasis is associated with increased cardiovascular risk. Endothelial, platelet, and erythrocyte microvesicles (MVs) are novel biomarkers of endothelial dysfunction and thromboinflammation. We explored whether MVs of different cell types are elevated in patients with psoriasis, and investigated potential associations with disease severity and macrovascular function. Endothelial, platelet and erythrocyte MVs were measured using a standardized flow cytometry protocol in psoriasis patients and controls free from established cardiovascular disease. Carotid intima-media thickness (IMT) and pulse wave velocity (PWV) were measured as markers of subclinical atherosclerosis and arterial stiffness. Psoriasis severity was assessed with PASI (Psoriasis Area Severity Index). Both platelet (p < 0.001) and erythrocyte MVs (p = 0.046), yet not endothelial MVs, were significantly increased in patients with psoriasis (n = 41) compared with controls (n = 41). Patients with higher PASI (≥10) presented significantly higher levels of ErMVs compared to those with lower PASI (<10) (p = 0.047). Carotid IMT and PWV were comparable between psoriasis patients and controls and did not significantly correlate with MVs. In the multivariate analysis, psoriasis was identified as an independent predictor of both platelet (p < 0.001) and erythrocyte MVs (p = 0.043), while hypertension was independently associated with endothelial MVs (p < 0.001). Increased formation of platelet and erythrocyte MVs may be evident in psoriasis patients and is indicative of prothrombotic, proinflammatory microenvironment, even in the absence of subclinical macrovascular dysfunction and before the clinical onset of overt cardiovascular complications. Potential mechanistic links and prognostic implications of increased MVs in psoriasis warrant further investigation.

Platelet Metabolic Flexibility: A Matter of Substrate and Location

Platelets are cellular elements that are physiologically involved in hemostasis, inflammation, thrombotic events, and various human diseases. There is a link between the activation of platelets and their metabolism. Platelets possess considerable metabolic versatility. Although the role of platelets in hemostasis and inflammation is known, our current understanding of platelet metabolism in terms of substrate preference is limited. Platelet activation triggers an oxidative metabolism increase to sustain energy requirements better than aerobic glycolysis alone. In addition, platelets possess extra-mitochondrial oxidative phosphorylation, which could be one of the sources of chemical energy required for platelet activation. This review aims to provide an overview of flexible platelet metabolism, focusing on the role of metabolic compartmentalization in substrate preference, since the metabolic flexibility of stimulated platelets could depend on subcellular localization and functional timing. Thus, developing a detailed understanding of the link between platelet activation and metabolic changes is crucial for improving human health.

Cardiovascular comorbidity in psoriasis - psoriatic inflammation is more than just skin deep

BACKGROUND

There is a growing understanding of inflammation in psoriasis beyond its dermatological manifestation, towards systemic inflammation. Management of possible comorbidities encompassing psychological, metabolic and cardiovascular disease is recommended in national and international dermatology guidelines for treatment of psoriasis patients. Vice versa, psoriasis is being recognized as a new risk factor for cardiovascular inflammation within the cardiological community.

METHODS

A review of the literature was conducted. Key points regarding epidemiological, mechanistic and management aspects were summarized and put into context for physicians treating psoriasis patients.

RESULTS

Efforts are currently being made to better understand the mechanistic underpinnings of systemic inflammation within psoriatic inflammation. Studies looking to "hit two birds with one stone" regarding specifically cardiovascular comorbidities of psoriasis patients using established systemic dermatological therapies have so far provided heterogeneous data. The diagnosis of psoriasis entails preventive and therapeutic consequences regarding concomitant diseases for the individual patient.

CONCLUSIONS

The knowledge of comorbidities in psoriasis calls for pronounced interdisciplinary care of psoriasis patients, to which this article highlights efforts regarding vascular inflammation and cardiovascular disease.

The Growth Factor Release from a Platelet-Rich Plasma Preparation Is Influenced by the Onset of Guttate Psoriasis: A Case Report

The involvement of platelets in immune and inflammatory processes is generally recognized; nevertheless, in psoriasis, their role is not clearly understood. We studied the in vitro growth factor release from a platelet-rich plasma preparation, the concentrated growth factors (CGF), in a case of a psoriasis subject three days before the onset of the papule. The CGF clots were incubated in a cell culture medium without growth supplements for 5 h and 1, 3, 6, 7, and 8 days, and the release kinetics of PDGF-AB, VEGF, TNF-α, and TGF-β1 were evaluated. The data, based on the results obtained during the case study, report a general increase in growth factor release in the psoriasis subject with respect to the healthy control, indicating an imbalance of growth factor production from blood cells. Although the results should be validated in the future, they show new aspects of this dermatological pathology, opening new possibilities both as the method of study, using CGF, and the involvement of platelets and growth factors in its development and maintenance.

Defining imaging sub-phenotypes of psoriatic arthritis: integrative analysis of imaging data and gene expression in a PsA patient cohort

OBJECTIVES

To define imaging sub-phenotypes in patients with PsA; determine their association with whole blood gene expression and identify biological pathways characterizing the sub-phenotypes.

METHODS

Fifty-five patients with PsA ready to initiate treatment for active disease were prospectively recruited. We performed musculoskeletal ultrasound assessment of the extent of inflammation in the following domains: synovitis, peritenonitis, tenosynovitis and enthesitis. Peripheral whole blood was profiled with RNAseq, and gene expression data were obtained. First, unsupervised cluster analysis was performed to define imaging sub-phenotypes that reflected the predominant tissue involved. Subsequently, principal component analysis was used to determine the association between imaging-defined sub-phenotypes and peripheral blood gene expression profile. Pathway enrichment analysis was performed to identify underlying mechanisms that characterize individual sub-phenotypes.

RESULTS

Cluster analysis revealed three imaging sub-phenotypes: (i) synovitis predominant [n = 31 (56%)]; (ii) enthesitis predominant [n = 13 (24%)]; (iii) peritenonitis predominant [n = 11 (20%)]. The peritenonitis-predominant sub-phenotype had the most severe clinical joint involvement, whereas the enthesitis-predominant sub-phenotype had the highest tender entheseal count. Unsupervised clustering of gene expression data identified three sub-phenotypes that partially overlapped with the imaging sub-phenotypes suggesting biological and clinical relevance of these sub-phenotypes. We therefore characterized enriched differential pathways, which included: immune system (innate system, B cells and neutrophil degranulation), complement system, platelet activation and coagulation function.

CONCLUSIONS

We identified three sub-phenotypes based on the predominant tissue involved in patients with active PsA. Distinct biological pathways may underlie these imaging sub-phenotypes seen in PsA, suggesting their biological and clinical importance.