MCP-1 mRNA expression in basal keratinocytes of psoriatic lesions

Bioinformatics and Systems Biology Approach to Identify the Pathogenetic Link Between Psoriasis and Cardiovascular Disease

Objective

This study aimed to identify hub genes and common pathways shared between psoriasis and cardiovascular disease (CVD) using bioinformatics analysis and predict the transcription factors (TFs) of hub genes.

Methods

GSE133555 data from the Gene Expression Omnibus (GEO) database were used to identify differentially expressed genes (DEGs) between involved and uninvolved skin lesions in psoriasis, employing the limma package in R. Additionally, CVD-related genes were obtained from the GeneCards database. The intersection of DEGs and CVD-related genes yielded CVD-DEGs. Gene Ontology and signaling pathway analyses were performed using the clusterProfiler package in R. Hub genes were identified by intersecting six algorithms in the CytoHubba plugin of Cytoscape. To identify potential biomarkers, the GSE14905 dataset was subjected to receiver operating characteristic analysis, resulting in the identification of eight central hub genes. Finally, the NetworkAnalyst web tool was used to identify the TFs of the eight hub genes.

Results

We identified 92 significant DEGs out of 1825 CVD-related genes in psoriasis obtained from the GSE13355 and GeneCard data. Functional enrichment analysis revealed the involvement of these genes in various signaling pathways, including the interleukin-17 signaling, tumor necrosis factor signaling, lipid and atherosclerosis, chemokine signaling, and cytokine signaling pathways in the immune system. The eight hub genes identified included interleukin-1 beta, C-X-C motif chemokine ligand 8, signal transducer and activator of transcription 3, C-C motif chemokine ligand 2, arginase 1, C-X-C motif chemokine receptor 4, cyclin D1, and matrix metallopeptidase 9, with forkhead box C1 also identified as an associated TF of these genes. These hub genes and TF may act as key regulators in the context of CVD.

Conclusion

This study identified several hub genes and signaling pathways associated with both CVD and psoriasis. These findings lay the groundwork for potential therapeutic interventions for patients with psoriasis affected by CVD.

Evaluation of IL-10, MCP-1, IFN gamma, and protectin D1 levels in patients with Hashimoto's thyroiditis

PURPOSE

Hashimoto's thyroiditis (HT) is one of the most prevalent autoimmune endocrine diseases and caused by the loss of immune tolerance for the thyroid gland. Many pathophysiological mechanisms were speculated about the development of HT. In our study, we aimed to reveal the relationship between HT and IL-10, MCP-1, IFNɤ, and PD1 levels and compare them with control subjects.

METHODS

We collected 37 patients with HT and 25 controls referred to our outpatient clinic. The diagnosis of HT was based on the detection of circulating antibodies to thyroid antigens and decreasing echogenicity on thyroid USG in patients with appropriate clinical characteristics. Serum IL-10, MCP-1, IFNɤ, and PD1 levels were detected using an ELISA KIT (96 T) method according to the manufacturer's instructions.

RESULTS

All subjects were euthyroid (median TSH level was 1.68 mU/L in HT vs 1.83 mU/L in the controls, p = 0.672). Twenty-three of 37 patients with HT were taking L-thyroxin replacement. Levels of serum IL-10, IFNɤ, and PD1 in patients with HT were higher than the controls, but the differences were not statistically significant (p = 0.393, p = 0.495, and p = 0.052 respectively). The serum levels of MCP-1 in HT patients were statistically different and higher than the controls (p = 0.018). Correlation analysis displayed significant associations between IL-10, MCP-1, IFNɤ, and PD1 levels.

CONCLUSION

Our study demonstrated that serum MCP-1 levels in HT patients were significantly increased; on the other hand, significant difference was not found between HT patients and the controls in terms of serum IL-10, IFNɤ, and PD1 levels.

C-C motif chemokine ligand 2 promotes myogenesis of myoblasts via the AKT-mTOR pathway

Muscle mass decreases with aging, while the C-C motif chemokine ligand 2 (CCL2) increases with aging; in this context, CCL2 can be considered a potential aging-promoting factor. Thus, CCL2 knockout mice are expected to exhibit anti-aging effects including protection against loss of muscle mass. However, instead, muscle amount and recovery of damaged muscles are decreased in CCL2 knockout mice. Therefore, we hypothesized that increasing CCL2 in the elderly might be related to compensation for loss of muscle mass. To confirm the relationship between muscle and CCL2, we sought to establish the role of CCL2 in C2C12 cells and Human Skeletal Muscle Myoblast (HSMM) cells. The myotube (MT) fusion index increased with CCL2 compared to 5day CCL2 vehicle only (27.0 % increase, P<0.05) in immunocytochemistry staining (ICC) data. CCL2 also restored MTs atrophy caused by dexamethasone (21.8 % increase, P<0.0001). p-mTOR/mTOR and p-AKT/total AKT increased with CCL2 compared to CCL2 vehicle only (18.3 and 30.5% increase respectively, P<0.05) and decreased with CCR2-siRNA compared to CCL2 (38.9 % (P<0.05) and 56.7% (P<0.005) reduction respectively). In conclusion, CCL2 positively affects myogenesis by CCR2 via AKT-mTOR signaling pathways. CCL2 might have potential as a therapeutic target for low muscle mass and muscle recovery.

Serum levels of C‐C motif chemokine ligand 2 and interleukin‐8 as possible biomarkers in patients with toxic epidermal necrolysis accompanied by acute respiratory distress syndrome

Toxic epidermal necrolysis (TEN) is a fatal cutaneous adverse reaction that occasionally affects multiple organs. Acute respiratory distress syndrome (ARDS) is a rare complication that can cause rapid and potentially fatal pulmonary dysfunction. However, the mechanisms underlying TEN-induced ARDS remain unknown. This retrospective single-center study aimed to identify potential biomarkers for predicting ARDS onset in TEN patients. Pre-treatment serum samples were collected from 16 TEN patients and 16 healthy controls (HCs). The serum levels of cytokines/chemokines were determined using the Luminex Assay Human Premixed Multi-analyte kit. The expression levels of cytokines and chemokines in the skin were examined via immunohistochemistry. The serum levels of C-C motif chemokine ligand 2 (CCL2), interleukin (IL)-6, and IL-8 were significantly higher in TEN patients with ARDS than in those without ARDS and in HCs, whereas those of CCL2 and IL-8 were not significantly different between TEN patients without ARDS and HCs. There was no significant difference in CCL2 and IL-8 expression in the skin between TEN patients with and without ARDS. Interestingly, there were no significant differences in the cytokine/chemokine levels between TEN and other organ damage, other than ARDS and TEN without any organ damage. We further analyzed the changes in cytokine/chemokine levels before and after treatment in two TEN patients with ARDS. CCL2, IL-6, and IL-8 levels decreased after systemic treatment compared to their baseline levels before treatment at an early stage. These results suggest that IL-8 and CCL2 may be involved in the pathogenesis of TEN-induced ARDS and have potential application as predictive markers for ARDS onset.

Elevation of IgE in patients with psoriasis: Is it a paradoxical phenomenon?

Immunoglobulin E (IgE) elevation is a hallmark of allergic conditions such as atopic dermatitis (AD). The pathogenesis of AD is typically associated with high levels of IL-4 and IL-13 produced by activated T helper 2 (Th2) cells. Psoriasis, on the other hand, is an inflammatory skin disease mainly driven by Th17 cells and their related cytokines. Although the immunopathologic reactions and clinical manifestations are often easily distinguished in the two skin conditions, patients with psoriasis may sometimes exhibit AD-like manifestations, such as elevated IgE and persistent pruritic lesions. Given the fact that the effective T cells have great plasticity to re-differentiate in response to innate and environmental factors, this unusual skin condition could be a consequence of a cross-reaction between distinct arms of T-cell and humoral immunity. Here we review the literature concerning the roles of IgE in the development of AD and psoriasis, showing that elevated IgE seems to be an important indicator for this non-typical psoriasis.

Dendritic Cells and Macrophages in the Pathogenesis of Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by scaly indurated erythema. This disease impairs patients’ quality of life enormously. Pathological findings demonstrate proliferation and abnormal differentiation of keratinocytes and massive infiltration of inflammatory immune cells. The pathogenesis of psoriasis is complicated. Among immune cells, dendritic cells play a pivotal role in the development of psoriasis in both the initiation and the maintenance phases. In addition, it has been indicated that macrophages contribute to the pathogenesis of psoriasis especially in the initiation phase, although studies on macrophages are limited. In this article, we review the roles of dendritic cells and macrophages in the pathogenesis of psoriasis.

Relationship between Immune Cells, Depression, Stress, and Psoriasis: Could the Use of Natural Products Be Helpful?

Psoriasis is one of the most widespread chronic inflammatory skin diseases, affecting about 2%-3% of the worldwide adult population. The pathogenesis of this disease is quite complex, but an interaction between genetic and environmental factors has been recognized with an essential modulation of inflammatory and immune responses in affected patients. Psoriatic plaques generally represent the clinical psoriatic feature resulting from an abnormal proliferation and differentiation of keratinocytes, which cause dermal hyperplasia, skin infiltration of immune cells, and increased capillarity. Some scientific pieces of evidence have reported that psychological stress may play a key role in psoriasis, and the disease itself may cause stress conditions in patients, thus reproducing a vicious cycle. The present review aims at examining immune cell involvement in psoriasis and the relationship of depression and stress in its pathogenesis and development. In addition, this review contains a focus on the possible use of natural products, thus pointing out their mechanism of action in order to counteract clinical and psychological symptoms.

Chemokine production induced by Corynebacterium pseudotuberculosis in a murine model

Corynebacterium pseudotuberculosis is the etiological agent of caseous lymphadenitis. The main clinical sign of this disease is the development of granulomas, especially in small ruminants; however, the pathways that are involved in the formation and maintenance of these granulomas are unknown. Cytokines and chemokines are responsible for the migration of immune cells to specific sites and tissues; therefore, it is possible that chemokines participate in abscess formation. This study aimed to evaluate the induction of chemokine production by two C. pseudotuberculosis strains in a murine model. A highly pathogenic (VD57) and an attenuated (T1) strain of C. pseudotuberculosis, as well as somatic and secreted antigens derived from these strains, was used to stimulate murine splenocytes. Then, the concentrations of the chemokines CCL-2, CCL-3, CCL-4, and CCL-5 and the cytokines IL-1 and TNF were measured in the culture supernatants. The VD57 strain had a higher ability to stimulate the production of chemokines when compared to T1 strain, especially in the early stages of stimulation, which can have an impact on granuloma formation. The T1 lysate antigen was able to stimulate most of the chemokines studied herein when compared to the other antigenic fractions of both strains. These results indicate that C. pseudotuberculosis is a chemokine production inducer, and the bacterial strains differ in their induction pattern, a situation that can be related to the specific behavior of each strain.

Alantolactone Suppresses Proliferation and the Inflammatory Response in Human HaCaT Keratinocytes and Ameliorates Imiquimod-Induced Skin Lesions in a Psoriasis-Like Mouse Model

Psoriasis is an immune-mediated inflammatory disease that affects 2% to 3% of the world population. Alantolactone, a sesquiterpene lactone, was isolated from Inula helenium and Radix inulae and has several biological effects, including antifungal, anthelmintic, antimicrobial, anti-inflammatory, antitrypanosomal, and anticancer properties. This study aimed to evaluate the antipsoriatic potential of alantolactone in vitro and in vivo and to explore its underlying mechanisms. These results showed that alantolactone significantly attenuated IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) cytokine-induced hyperproliferation in HaCaT keratinocytes. Moreover, M5 cytokines significantly upregulated the mRNA levels of TNF-α, IL-6, IL-1β, and IL-8. However, alantolactone attenuated the upregulation of these inflammatory cytokines. In addition, alantolactone was found to inhibit STAT3 phosphorylation and NF-κB p65 nuclear translocation in HaCaT keratinocytes. Furthermore, alantolactone treatment in mice significantly alleviated the severity of skin lesions (erythema, scaling and epidermal thickness, and inflammatory cell infiltration) and decreased the mRNA expression of inflammatory cytokines (e.g., TNF-α, IL-6, IL-1β, IL-8, IL-17A, and IL-23) in an IMQ-induced-like mouse model. Therefore, our new findings revealed that alantolactone alleviates psoriatic skin lesions by inhibiting inflammation, making it an attractive candidate for future development as an antipsoriatic agent.

Macrophages in dermatology: pathogenic roles and targeted therapeutics

The field of macrophage biology is rapidly growing. Recent studies have shifted focus from classic wound healing roles to newly identified roles in dermatologic pathology. These studies have identified pathogenic roles of macrophages in relatively common conditions, such as psoriasis, skin cancer, and cutaneous T-cell lymphoma. Selective depletion of these cells or their associated cytokines leads to improved clinical outcome. Herein, we review recent animal and human studies that have elucidated novel pathogenic roles of macrophages in conditions frequently encountered by dermatologists and discuss clinically relevant macrophage-targeted therapies.

Natural Compound Mixture, Containing Emodin, Genipin, Chlorogenic Acid, Cimigenoside, and Ginsenoside Rb1, Ameliorates Psoriasis-Like Skin Lesions by Suppressing Inflammation and Proliferation in Keratinocytes

Herbal combinations of Rhei Radix et Rhizoma, Gardeniae Fructus, Cimicifugae Rhizoma, and Ginseng Radix have been used in traditional formulas to treat the symptoms of heat and dryness. This study investigated the therapeutic effects of a natural compound mixture (PSM) of these herbal combinations, containing emodin, genipin, chlorogenic acid, cimigenoside, and ginsenoside Rb1, for the treatment of psoriasis and its underlying molecular mechanisms. PSM was applied topically to the dorsal skin lesions of imiquimod- (IMQ-) induced C57BL/6 mice, and the expression of the proinflammatory mediators was investigated. The topical application of 1% PSM reduced psoriasis-like symptoms in IMQ-induced C57BL/6 mice significantly. PSM also attenuated the production of IFN-γ, IL-1β, and IL-6 in skin lesions. Histological analysis showed that PSM had antipsoriatic effects by reducing the lesional epidermal thickness. Either M5 (IL-1α, IL-17A, IL-22, oncostatin M, and TNF-α, 10 ng/ml each) or IL-22- (100 ng/ml) stimulated HaCaT cells were used to examine the efficacy and underlying mechanism of PSM. In M5-stimulated HaCaT cells, PSM inhibited the production of C-X-C motif chemokine ligand (CXCL) 10 and C-C motif chemokine ligand (CCL) 20 effectively. Moreover, compared to the use of a single compound, it had synergistic inhibitory effects in CXCL8 production. PSM suppressed the phosphorylation of ERK1/2, p38, and STAT3 signaling pathways in M5-stimulated HaCaT cells. Furthermore, PSM reduced the proliferation rate and K16 and K17 expressions in IL-22-stimulated HaCaT cells by inhibiting the Akt/mTOR signaling pathway. These results suggest that PSM may have a therapeutic potential in the treatment of psoriasis lesions.

Daphnetin inhibits proliferation and inflammatory response in human HaCaT keratinocytes and ameliorates imiquimod-induced psoriasis-like skin lesion in mice

BACKGROUND

Psoriasis is a common chronic inflammatory skin disease. Keratinocytes hyperproliferation and excessive inflammatory response contribute to psoriasis pathogenesis. The agents able to attenuate keratinocytes hyperproliferation and excessive inflammatory response are considered to be potentially useful for psoriasis treatment. Daphnetin exhibits broad bioactivities including anti-proliferation and anti-inflammatory. This study aims to evaluate the anti-psoriatic potential of daphnetin in vitro and in vivo, and explore underlying mechanisms.

METHODS

HaCaT keratinocytes was stimulated with the mixture of IL-17A, IL-22, oncostatin M, IL-1α, and TNF-α (M5) to establish psoriatic keratinocyte model in vitro. Cell viability was measured using Cell Counting Kit-8 (CCK-8). Quantitative Real-Time PCR (qRT-PCR) was performed to measure the mRNA levels of hyperproliferative marker gene keratin 6 (KRT6), differentiation marker gene keratin 1 (KRT1) and inflammatory factors IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. Western blotting was used to detect the protein levels of p65 and p-p65. Indirect immunofluorescence assay (IFA) was carried out to detect p65 nuclear translocation. Imiquimod (IMQ) was used to construct psoriasis-like mouse model. Psoriasis severity (erythema, scaling) was scored based on Psoriasis Area Severity Index (PASI). Hematoxylin and eosin (H&E) staining was performed to examine histological change in skin lesion. The expression of inflammatory factors including IL-6, TNF-α, IL-23A and IL-17A in skin lesion was measured by qRT-PCR.

RESULTS

Daphnetin attenuated M5-induced hyperproliferation in HaCaT keratinocytes. M5 stimulation significantly upregulated mRNA levels of IL-1β, IL-6, IL-8, TNF-α, IL-23A and MCP-1. However, daphnetin treatment partially attenuated the upregulation of those inflammatory cytokines. Daphnetin was found to be able to inhibit p65 phosphorylation and nuclear translocation in HaCaT keratinocytes. In addition, daphnetin significantly ameliorate the severity of skin lesion (erythema, scaling and epidermal thickness, inflammatory cell infiltration) in IMQ-induced psoriasis-like mouse model. Daphnetin treatment attenuated IMQ-induced upregulation of inflammatory cytokines including IL-6, IL-23A and IL-17A in skin lesion of mice.

CONCLUSIONS

Daphnetin was able to attenuate proliferation and inflammatory response induced by M5 in HaCaT keratinocytes through suppression of NF-κB signaling pathway. Daphnetin could ameliorate the severity of skin lesion and improve inflammation status in IMQ-induced psoriasis-like mouse model. Daphnetin could be an attractive candidate for future development as an anti-psoriatic agent.

Keratinocyte autophagy enables the activation of keratinocytes and fibroblastsand facilitates wound healing

Macroautophagy/autophagy is a cellular catabolic process that is implicated in several physiological and pathological processes. However, the role of epidermal autophagy in wound healing remains unknown. Here, using mice with genetic ablation of the essential Atg5 (autophagy related 5) or Atg7 (autophagy related 7) in their epidermis to inhibit autophagy, we show that keratinocyte autophagy regulates wound healing in mice. Wounding induces the expression of autophagy genes in mouse skin. Epidermis-specific autophagy deficiency inhibits wound closure, re-epithelialization, keratinocyte proliferation and differentiation, dermal granulation tissue formation, and infiltration of immune cells including macrophages, neutrophils, and mast cells, while it does not affect angiogenesis. Using cytokine array screening, we found that autophagy deficiency inhibits the transcription and production of the cytokine CCL2/MCP-1 by TNF. At the molecular level, TNF induces autophagic flux and the expression of autophagy genes through NFKB in epidermal keratinocytes. TNF promotes CCL2 transcription through the autophagy-AMPK-BRAF-MAPK1/3/ERK-activator protein 1 (AP1) pathway. Indeed, treating mice with recombinant CCL2 can reverse the effect of autophagy deficiency in keratinocytes. At the cellular level, we found that CCL2 induction via autophagy in keratinocytes is required not only for keratinocyte migration and proliferation but also for dermal fibroblast activation. Our findings demonstrate a critical role of epidermal autophagy in wound healing in vivo and elucidate a critical molecular machinery coordinating keratinocyte-fibroblast interaction in skin repair.Abbreviations: ACTA2/α-SMA: actin alpha 2, smooth muscle; ACTB: β-actin; ADGRE1: adhesion G protein-coupled receptor E1; AMPK: AMP-activated protein kinase; AP1: activator protein 1; AP1-RE: AP1 response element; ATG: autophagy-related; ATG16L1: autophagy related 16 like 1; BECN1: beclin 1; BRAF: B-Raf proto-oncogene, serine/threonine kinase; C5: complement C5; CCL2/MCP-1: C-C motif chemokine ligand 2; CCL3: C-C motif chemokine ligand 3; CK: cytokeratin; cKO: conditional knockout; CRTC1: CREB-regulated transcription coactivator 1; CXCL1: C-X-C motif chemokine ligand 1; CXCL2: C-X-C motif chemokine ligand 2; ECM: extracellular matrix; EGF: epidermal growth factor; FGF7: fibroblast growth factor 7; GABARAPL2: GABA type A receptor associated protein like 2; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; HBEGF: heparin binding EGF like growth factor; HPRT1: hypoxanthine phosphoribosyltransferase 1; IHC: immunohistochemical; IL1B: interleukin 1 beta; KRT10: keratin 10; KRT14: keratin 14; MAP1LC3B/LC3B-I/II: microtubule-associated protein 1 light chain 3 beta; MAPK1/3/ERK: mitogen-activated protein kinase 1/3; MKI67/Ki-67: marker of proliferation; MPO: myeloperoxidase; NFKB: NF-kappa B, nuclear factor kappa-light-chain-enhancer of activated B cells; NFKB-RE: NFKB response element; PDGF: platelet-derived growth factor; PECAM1: platelet and endothelial cell adhesion molecule 1; PRKAA1: protein kinase AMP-activated catalytic subunit alpha 1; RELA/p65: RELA proto-oncogene, NFKB subunit; shCON: small hairpin negative control; siNC: negative control; siRNA: small interfering RNA; SP1: sp1 transcription factor; SQSTM1/p62: sequestosome 1; TGFA: transforming growth factor alpha; TGFB1: transforming growth factor beta 1; TIMP1: TIMP metallopeptidase inhibitor 1; TNF/TNF-alpha: tumor necrosis factor; TREM1: triggering receptor expressed on myeloid cells 1; WT: wild-type.

Single-cell RNA-Seq reveals the transcriptional landscape and heterogeneity of skin macrophages in Vsir-/- murine psoriasis

Rationale: V-domain immunoglobulin suppressor of T cell activation (VISTA) is a novel inhibitory immune checkpoint molecule. Vsir-/- mice have exacerbated psoriasis-like skin inflammation. The immune cell subsets involved in inflammation in Vsir-/- psoriatic mice are largely unknown. We have used scRNA-seq as an unbiased profiling strategy to study the heterogeneity of immune cells at a single cell level in the skin of Vsir-/- psoriatic mice. Methods: In the present study, the right ear and shaved back skin of wild type and Vsir-/- mice were treated with IMQ for 5 consecutive days to induce psoriasis-like dermatitis. Then, the single-cell RNA sequencing analysis of mouse back skin lesions was performed using 10 × Genomics technique. Results: We identified 12 major cell subtypes among 23,258 cells. The major populations of the skin cells included macrophages, dendritic cells and fibroblasts. Macrophages constituted the main immune cell population in the WT (61.29%) and Vsir-/- groups (77.7%). It should be noted that DCs and fibroblasts were expanded in the Vsir-/- psoriatic mice. Furthermore, the gene expression signatures were assessed. We observed that Hspb1 and Cebpb were significantly upregulated in the Vsir-/- psoriatic mice. Differential gene expression and gene ontology enrichment analyses revealed specific gene expression patterns distinguishing these subsets and uncovered putative functions of each cell type. Date analysis resulted in the discovery of a number of novel psoriasis-associated genes in Vsir-/- mice. Conclusion: We present a comprehensive single-cell landscape of the skin immune cells in Vsir-/- psoriatic mice. These unprecedented data uncovered the transcriptional landscape and phenotypic heterogeneity of skin macrophages in psoriasis and identified their gene expression signature suggesting specialized functions in Vsir-/- mice. Our findings will open novel opportunities to investigate the role of VISTA in driving psoriasis.

Delayed application of silver nanoparticles reveals the role of early inflammation in burn wound healing

Burn injury is common, and antimicrobial agents are often applied immediately to prevent wound infection and excessive inflammatory response. Although inflammation is essential for clearing bacteria and creating an environment conducive to the healing process, it is unclear what time-frame inflammation should be present for optimal wound healing. This study critically investigated the role of early inflammation in burn wound healing, and also revealed the molecular mechanisms underlying the pro-healing effects of silver nanoparticles (AgNPs). We created a burn injury mouse model using wild-type and Smad3−/− mice, which were topically treated with AgNPs at different post-burn days, and examined the healing processes of the various groups. We also delineated the molecular pathways underlying the anti-inflammation and pro-healing effects of AgNPs by morphological and histological analysis, immuno-histochemistry, and western blotting. Our results showed that (1) AgNPs regulated pro-inflammatory cytokine IL-6 production of keratinocytes and neutrophils infiltration through KGF-2/p38 signaling pathway, (2) Topical AgNPs treatment immediately after burn injury significantly supressed early inflammation but resulted in delayed healing, (3) A short delay in AgNPs application (post-burn day 3 in our model) allowed early inflammation in a controlled manner, and led to optimal burn wound healing. Thus, our current study showed that some degree of early inflammation was beneficial, but prolonged inflammation was detrimental for burn wound healing. Further evaluation and clinical translation of this finding is warranted.

Biomechanical Factors in Psoriatic Disease: Defective Repair Exertion as a Potential Cause. Hypothesis Presentation and Literature Review

Joining main clinical manifestations of psoriatic skin disorder are inflammatory arthritis and nail lesions. Repetitive microdamage has been postulated as a main triggering factor in lesions of psoriatic arthritis. This concept of psoriatic disease might also be admissible for triggering nail lesions because the nail is a frequently traumatized structure. Here, we aimed to describe the conjectural injury mechanisms of nail complex with regard to acting biomechanical factors. Tissue repair response to physical microdamage may be altered in psoriatic disease. It is plausible to consider that a defective repair process in the dysregulated prepsoriatic tissue may lead to innate immune activation and further development of autoinflammatory lesions, although excessive inflammation is known to impair wound healing. Recently published data have revealed the importance of mechanosensitive Wingless-type (Wnt) signaling in the pathophysiology of psoriasis and ankylosing spondylitis. The Wnt signaling system is involved in morphogenesis, repair, and regeneration as a biologic process main regulator. Wnt5a seems to be a dominating mediator in both psoriatic plaques and during the spondylitis process that might also be a linking molecule of psoriatic response to mechanical stress. Future studies should focus on complex responsive interactions of tissue repair regulators regarded in psoriatic disease.

Comparative Transcriptomics Reveals the Role of the Toll-Like Receptor Signaling Pathway in Fluoride-Induced Cardiotoxicity

Many studies have shown that fluorosis due to long-term fluoride intake has damaging effects on the heart. However, the mechanisms underlying cardiac fluorosis have not been illuminated in detail. We performed high-throughput transcriptome sequencing (RNA-Seq) on rat cardiac tissue to explore the molecular effects of NaF exposure. In total, 372 and 254 differentially expressed genes (DEGs) were identified between a group given 30 mg/L NaF and control and between a group given 90 mg/L NaF and control, respectively. The transcript levels of most of these genes were significantly down-regulated and many were distributed in the Toll-like receptor signaling pathway. Transcriptome analysis revealed that herpes simplex infection, ECM-receptor interaction, influenza A, cytokine-cytokine receptor interaction, apoptosis, and Toll-like receptor signaling pathway were significantly affected. IL-6 and IL-10 may play a crucial role in the cardiac damage caused by NaF as external stimuli according to protein-protein interaction (PPI) network analysis. The results of qRT-PCR and Western blotting showed a marked decreased mRNA and protein levels of IL-1, IL-6, and IL-10 in the low concentration fluoride (LF) and high concentration fluoride (HF) groups, which was in agreement with RNA-Seq results. This is the first study to investigate NaF-induced cardiotoxicity at a transcriptome level.

Downregulated Caveolin-1 expression in circulating monocytes may contribute to the pathogenesis of psoriasis

Caveolin-1 (CAV-1) is the principal component of caveolae that regulates a variety of signaling molecules and receptors. Our previous study revealed CAV-1 reduction in the epidermis of patients with psoriasis, which leads to enhanced Janus kinase/signal transducer and activator of transcription activation and cytokine production, suggesting that aberrant CAV-1 expression may contribute to psoriatic inflammation. This study aimed to investigate whether abnormal modulation of CAV-1 on immune cells is involved in the pathogenesis of psoriasis. We observed that CAV-1 level in psoriasis patients was apparently reduced in peripheral blood mononuclear cells (PBMCs) and it was prominent in CD14⁺ monocytes. CAV-1 silencing in monocytes represented elevated levels of interleukin (IL)-1β and IL-6, and those had enhanced chemotaxis activity. In a murine model of psoriasis-like inflammation induced by imiquimod, we observed a significant CAV-1 reduction in PBMCs. Systemic administration of CAV-1 scaffolding domain peptide significantly improved the skin phenotype with less macrophage infiltration. Taken together, aberrant CAV-1 expression in monocytes may be involved in the pathogenesis of psoriasis.

Psoriasis: Keratinocytes or Immune Cells - Which Is the Trigger?

BACKGROUND

Psoriasis is a common, chronic inflammatory skin disorder, which can significantly impact quality of life. Despite major breakthroughs in our understanding of the pathogenesis of psoriasis, the chronological order of the underlying mechanisms leading to the development of psoriatic plaques remains to be completely understood.

SUMMARY

Although psoriasis is classically perceived as a T-cell disease, it is now well recognized that T lymphocytes do not function in exclusivity. This theory is supported by evidence from transgenic murine models that develop marked psoriasiform disease. In addition, immune cells and cytokines regulate both early and late events involved in the pathogenesis of psoriasis. Key Messages: Psoriasis is a complex disease - a dynamic interplay between immune cells, keratinocytes, and various other skin-resident cells, such as endothelial and immune cells. The contribution of each cell type is crucial in the initiation and maintenance phases of psoriatic alterations.

Association of CCL2 with systemic inflammation in Schnitzler syndrome

BACKGROUND

Schnitzler syndrome (SchS) is a rare autoinflammatory disease characterized by urticarial exanthema, bone and joint alterations, fever and monoclonal gammopathy, which manifest mostly in the second half of life. It involves overactivation of the interleukin (IL)-1 system, but the exact pathophysiological pathways remain largely unknown.

OBJECTIVES

To identify and characterize the pathogenetic players in SchS.

METHODS

Blood parameters were quantified in patients with SchS compared with healthy controls and patients with psoriasis and hidradenitis suppurativa using enzyme-linked immunosorbent assay (ELISA). CCL2 expression in cultured primary cells was analysed by quantitative reverse-transcriptase polymerase chain reaction and ELISA.

RESULTS

CCL2, a chemoattractant for monocytic and further mononuclear immune cells, was found to be significantly elevated in patients with SchS. CCL2 levels showed a positive association with global disease activity, especially with bone pain, but not disease duration, gammopathy, neutrophilia or skin disease. In vitro stimulation assays demonstrated a strong CCL2 production capacity of mononuclear immune cells and fibroblasts, but not epithelial or endothelial cells. Among a range of inflammatory mediators, only IL-1β (immune cells, fibroblasts) and tumour necrosis factor (TNF)-α (fibroblasts) were important CCL2 inducers. TNF-α, but not IL-17, strengthened the CCL2-inducing effect of IL-1β in fibroblasts. Accordingly, CCL2 levels positively correlated with both TNF-α and IL-1β serum levels in patients with SchS. Therapeutic IL-1β blockade decreased CCL2 blood levels in these patients as early as 1 week after the initiation of treatment.

CONCLUSIONS

CCL2 may be an important component of the pathogenetic cascade leading to bone alterations, and a suitable marker of disease activity in patients with SchS.

Potential risk to human skin cells from exposure to dicloran photodegradation products in water

Exposure to sunlight and certain pesticides can induce phototoxic responses. Long- and short-term exposure to the photoactivated pesticides can cause a variety of skin diseases. However, assessment of pesticide phototoxicity on human skin is difficult. In the present study, human skin keratinocytes were cultured in several forms: monolayer cell sheet, three-dimensional culture, and keratinocyte-fibroblast co-culture. A common fungicide, dicloran (DC, 2,6‑dichloro‑4‑nitroaniline), was irradiated with simulated sunlight for 2 (DC-PD-2h) and 4 (DC-PD-4h) hours. Dicloran, and two purified intermediate photodegradation products, 2‑chloro‑1,4‑benzoquinone (CBQ) and 1,4‑benzoquinone (BQ), were applied in toxicity tests independently with the keratinocyte culture models. The cell migration, cell differentiation, pro-inflammatory molecule production, and dermal fibroblast cell activation were all measured in the keratinocytes treated with the chemicals described above. These parameters were used as references for dicloran phototoxicity assessment. Among all tested chemicals, the DC-PD-4h and BQ demonstrated elevated toxicities to the keratinocytes compared to dicloran based on our results. The application of DC-PD-4h or BQ significantly delayed the migration of keratinocytes in monolayer cell sheets, inhibited the keratinocyte differentiation, increased the production of pro-inflammatory molecules by 3D keratinocyte culture, and enhanced the ability of 3D cultured keratinocytes in the activation of co-cultured dermal fibroblast cells. In contrast, dicloran, DC-PD-2h, and CBQ showed minimal effects on the keratinocytes in all assays. The results suggested that the four-hour photodegraded dicloran was likely to induce inflammatory skin diseases in the natural human skin. The 1,4‑benzoquinone, which is the predominant degradation product detected following 4 h of irradiation, was the main factor for this response. Photoactivation increased the risk of skin exposed to dicloran in nature. Our models provided an efficient tool in the assessment of toxicity changes in pesticide following normal use practices under typical environmental conditions.

Serum peptides as putative modulators of inflammation in psoriasis

BACKGROUND

Psoriasis is a refractory inflammatory disease, however, its pathophysiology is still not fully understood.

OBJECTIVE

We tried to identify novel serum peptides associated with the pathophysiology of psoriasis.

METHODS

Serum peptides from 24 patients with psoriasis vulgaris (PV), 10 patients with psoriatic arthritis (PsA), 14 patients with atopic dermatitis (AD), and 23 healthy control (HC) subjects were analyzed by mass spectrometry. The effects of some peptides on the secretion of humoral factors from dermal cells were investigated by cytokine arrays and ELISAs.

RESULTS

A total of 93 peptides were detected. 24, 20, 23, and 2 peptides showed at least 1.2-fold difference in ion intensity between the psoriasis (PV+PsA) and HC groups, between the PV+PsA and AD groups, between the PV and PsA groups, and between patients with severe-to-moderate PV (n=6) and those with mild PV (n=18), respectively (p<0.05). 13 out of 27 peptides that showed at least 1.5-fold ion intensity difference in the abovementioned 4 comparisons were identified. The parent proteins of the identified peptides included a coagulation factor, proteins involved in the maintenance of skin, and a protein relating to cytoskeleton. We focused on 2 peptides that were increased in the PV+PsA group: a fibrinogen α chain-derived peptide (1462m/z), the unmodified form of which was fibrinopeptide A-des-alanine (FPAdA), and a filaggrin (FLG)-derived peptide (1977m/z), a modified form of FLG_2099-2118 (Q₂₀₉₉pE, Q₂₁₁₅E; FLG-pEE). FPAdA stimulation increased the secretion of GROα from dermal microvascular endothelial cells (dMVECs) and decreased the secretion of lipocalin-2 from keratinocytes in comparison to FPAdA-resequenced peptide stimulation (GROα, 280.9±7.3pg/mL vs. 229.6±5.0pg/mL, p<0.001; lipocalin-2, 273±13pg/mL vs. 350±10pg/mL, p<0.01). Interestingly, FLG-pEE stimulation decreased the secretion of GROα, IL-8, and MCP-1 from dMVECs in comparison to FLG-derived control peptide stimulation (GROα, 844.3±47.5pg/mL vs. 1038.5±96.9pg/mL, p<0.05; IL-8, 2240.1±172.6pg/mL vs. 3221.8±523.7pg/mL, p<0.05; MCP-1, 4057.8±157.2pg/mL vs. 4619.1±213.4pg/mL, p<0.05).

CONCLUSIONS

The results suggested that some serum peptides are involved in the pathophysiology of psoriasis, regulating the secretion of inflammatory chemokines and an antimicrobial protein. The modulation of serum peptides may be a potential therapeutic strategy for psoriasis.

CC and CXC Chemokines Patterns in Psoriasis Determined by Protein Array Method Were Influenced by Goeckerman’s Therapy

Goeckerman’s therapy (GT) of psoriasis is based on daily application of pharmacy grade coal tar on affected skin with subsequent exposure to UV light. The aim of this study was to evaluate the influence of Goeckerman’s therapy of psoriasis on the levels of proangiogenic chemokines ENA-78 (CXCL5, Epithelial Cell Derived Neutrophil Attractant- 78), GRO alpha (CXCL1, Growth-Related Oncogene), IL-8 (CXCL8, Interleukin-8), MCP-1 (CCL2, Monocyte Chemotactic (Chemoattractant) Protein 1) and RANTES (CCL5, Regulated on Activation of Normal T Cell Expressed and Secreted) in peripheral blood of 22 children’s patients with psoriasis. 22 otherwise healthy children serve as a control group. The serum levels of chemokines were determined by commercial membrane protein array technique (RayBiotech, USA). Efficacy of Goeckerman’s therapy was delineated by PASI score. Disease activity was significantly diminished by Goeckerman’s therapy (p<0.001). Serum levels of GRO alpha and MCP-1 in patients before GT were significantly higher than those measured in healthy blood donors (GRO alpha: p=0.0128 and MCP-1: p=0.0003). Serum levels of GRO alpha, MCP-1 and RANTES were significantly diminished by GT (GRO alpha: p=0.002, MCP-1: p=0.048 and RANTES: p=0.0131). Compared to the healthy controls, serum level of MCP-1 remained significantly increased in psoriasis patients after GT (p<0.0001). In conclusion, we found that the GT of psoriasis influenced the serum levels of proinflammatory and proangiogenic chemokines, especially GRO alpha, MCP-1 and RANTES. It could be the cause for decreased proangiogenic activity which is described after GT of psoriasis.

Inflammation induces dermal Vγ4+ γδT17 memory-like cells that travel to distant skin and accelerate secondary IL-17-driven responses

Gamma delta (γδ) T cells represent a major IL-17 committed T-cell population (γδT17 cells) in the mouse dermis. Following exposure to the inflammatory agent imiquimod (IMQ) the Vγ4(+) subset of γδT cells produce IL-17 in the skin and expand rapidly in draining lymph nodes (LNs). Local IMQ treatment in humans is known to exacerbate psoriasis skin lesion activity at distant sites. Whether expanded γδT17 cells sensitize distant sites to inflammation has been unknown. Here we show that expanded Vγ4(+) γδT17 cells egress from LNs in a fingolimod (FTY720)-sensitive manner and use C-C chemokine receptor type 2 to accumulate in inflamed skin where they augment neutrophil recruitment and inflammation. They also travel to noninflamed skin and peripheral LNs and remain in elevated numbers at these distant sites for at least 3 mo. Sensitized mice show more rapid skin inflammation and greater proliferation and IL-17 production by Vγ4(+) γδT cells upon imiquimod challenge. Transfer experiments confirm that memory-like Vγ4(+) γδT17 cells respond more rapidly. Memory-like Vγ4(+) γδT17 cells are distinguished by greater IL-1R1 expression and more proliferation in response to IL-1β. These findings establish that local skin inflammation leads to faster and stronger secondary responses to the same stimulus through long-term and systemic changes in the composition and properties of the dermal γδT-cell population.

Genetic Epidemiology of Psoriasis

Psoriasis is a chronic, inflammatory, immune-mediated skin condition with a prevalence of 0-11.8% across the world. It is associated with a number of cardiovascular, metabolic, and autoimmune disease co-morbidities. Psoriasis is a multifactorial disorder, influenced by both genetic and environmental factors. Its genetic basis has long been established through twin studies and familial clustering. The association of psoriasis with the HLA-Cw6 allele has been shown in many studies. Recent genome-wide association studies have identified a large number of other genes associated with psoriasis. Many of these genes regulate the innate and adaptive immune system. These findings indicate that a dysregulated immune system may play a major role in the pathogenesis of psoriasis. In this article, we review the clinical and genetic epidemiology of psoriasis with a brief description of the pathogenesis of disease.

Heparanase is preferentially expressed in human psoriatic lesions and induces development of psoriasiform skin inflammation in mice

Heparanase is the sole mammalian endoglycosidase that selectively degrades heparan sulfate, the key polysaccharide associated with the cell surface and extracellular matrix of a wide range of tissues. Extensively studied for its capacity to promote cancer progression, heparanase enzyme was recently implicated as an important determinant in several inflammatory disorders as well. Applying immunohistochemical staining, we detected preferential expression of heparanase by epidermal keratinocytes in human psoriatic lesions. To investigate the role of the enzyme in the pathogenesis of psoriasis, we utilized heparanase transgenic mice in a model of 12-O-tetradecanoyl phorbol 12-myristate 13-acetate-induced cutaneous inflammation. We report that over-expression of the enzyme promotes development of mouse skin lesions that strongly recapitulate the human disease in terms of histomorphological appearance and molecular/cellular characteristics. Importantly, heparanase of epidermal origin appears to facilitate abnormal activation of skin-infiltrating macrophages, thus generating psoriasis-like inflammation conditions, characterized by induction of STAT3, enhanced NF-κB signaling, elevated expression of TNF-α and increased vascularization. Taken together, our results reveal, for the first time, involvement of heparanase in the pathogenesis of psoriasis and highlight a role for the enzyme in facilitating abnormal interactions between immune and epithelial cell subsets of the affected skin. Heparanase inhibitors (currently under clinical testing in malignant diseases) could hence turn highly beneficial in psoriatic patients as well.

MCP-1 in psoriatic patients: effect of biological therapy

BACKGROUND

Monocyte chemoattractant protein-1 (MCP-1) is a chemokine locally and systemically augmented in psoriasis. A single nucleotide polymorphism in MCP-1 promoter region -2518A→G is associated with higher gene expression.

OBJECTIVE

The aim was to evaluate MCP-1 plasma level in psoriatic patients and to relate any association in plasmatic and cutaneous MCP-1 with clinical improvement due to biological drugs.

METHODS

Blood samples were obtained from: (i) 30 Caucasian patients with psoriasis and 10 controls, for determining MCP-1 plasma concentrations and -2518A→G polymorphism occurrence, (ii) 16 psoriatic patients treated by anti-tumor necrosis factor-α (TNF-α) adalimumab/etanercept or by anti-CD-11 efalizumab, before and after 2 months of treatment. Moreover, biopsies were performed on lesional skin of five patients treated with anti-TNF-α. MCP-1 plasma concentration and cutaneous expression were determined by ELISA and qRT-PCR.

RESULTS

MCP-1 plasma level was significantly increased in psoriatic patients. -2518A→G polymorphism was similarly distributed in patients and controls and unrelated to MCP-1 plasma level or to Psoriasis Area and Severity Index. All patients receiving biological drugs showed significant clinical improvement. Anti-TNF-α therapy moderately reduced MCP-1 plasma concentration and robustly decremented MCP-1 expression in lesional skin.

CONCLUSION

MCP-1 should be a potential local inflammatory marker in psoriatic patients to assess disease severity and anti-TNF-α treatment efficacy.

IL-23 induces atopic dermatitis-like inflammation instead of psoriasis-like inflammation in CCR2-deficient mice

Psoriasis is an immune-mediated chronic inflammatory skin disease, characterized by epidermal hyperplasia and infiltration of leukocytes into the dermis and epidermis. IL-23 is expressed in psoriatic skin, and IL-23 injected into the skin of mice produces IL-22-dependent dermal inflammation and acanthosis. The chemokine receptor CCR2 has been implicated in the pathogenesis of several inflammatory diseases, including psoriasis. CCR2-positive cells and the CCR2 ligand, CCL2 are abundant in psoriatic lesions. To examine the requirement of CCR2 in the development of IL-23-induced cutaneous inflammation, we injected the ears of wild-type (WT) and CCR2-deficient (CCR2^−/−) mice with IL-23. CCR2^−/− mice had increased ear swelling and epidermal thickening, which was correlated with increased cutaneous IL-4 levels and increased numbers of eosinophils within the skin. In addition, TSLP, a cytokine known to promote and amplify T helper cell type 2 (Th2) immune responses, was also increased within the inflamed skin of CCR2^−/− mice. Our data suggest that increased levels of TSLP in CCR2^−/− mice may contribute to the propensity of these mice to develop increased Th2-type immune responses.

Gene profiling of narrowband UVB-induced skin injury defines cellular and molecular innate immune responses

The acute response of human skin to UVB radiation has not been fully characterized. We sought to define the cutaneous response at 24 hours following narrowband UVB (NB-UVB, 312-nm peak), a therapeutically relevant source of UVB, using transcriptional profiling, immunohistochemistry, and immunofluorescence. There were 1,522 unique differentially regulated genes, including upregulated genes encoding antimicrobial peptides (AMPs) (S100A7, S100A12, human beta-defensin 2, and elafin), as well as neutrophil and monocyte/dendritic cell (DC) chemoattractants (IL-8, CXCL1, CCL20, CCL2). Ingenuity pathway analysis demonstrated activation of innate defense and early adaptive immune pathways. Immunohistochemistry confirmed increased epidermal staining for AMPs (S100A7, S100A12, human beta-defensin 2, and elafin). Inflammatory myeloid CD11c(+)BDCA1(-) DCs were increased in irradiated skin, which were immature as shown by minimal colocalization with DC-LAMP, and coexpressed inflammatory markers tumor necrosis factor (TNF) and TNF-related apoptosis-inducing ligand in irradiated skin. There were increased BDCA3(+) DCs, a cross-presenting DC subtype with immunosuppressive functions, and these cells have not been previously characterized as part of the response to UVB. These results show that the acute response of human skin to erythemogenic doses of NB-UVB includes activation of innate defense mechanisms, as well as early infiltration of multiple subtypes of inflammatory DCs, which could serve as a link between innate and adaptive immunity.

3D-QSAR studies on CCR2B receptor antagonists: Insight into the structural requirements of (R)-3-aminopyrrolidine series of molecules based on CoMFA/CoMSIA models

Objective:

Monocyte chemo attractant protein-1 (MCP-1) is a member of the CC-chemokine family and it selectively recruits leukocytes from the circulation to the site of inflammation through binding with the chemotactic cytokine receptor 2B (CCR2B). The recruitment and activation of selected populations of leukocytes is a key feature in a variety of inflammatory conditions. Thus MCP-1 receptor antagonist represents an attractive target for drug discovery. To understand the structural requirements that will lead to enhanced inhibitory potencies, we have carried out 3D-QSAR (quantitative structure–activity relationship) studies on (R)-3-aminopyrrolidine series of molecules as CCR2B receptor antagonists.

Materials and Methods:

Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were performed on a series of (R)-3-aminopyrrolidine derivatives as antagonists of CCR2B receptor with Sybyl 6.7v.

Results:

We have derived statistically significant model from 37 molecules and validated it against an external test set of 13 compounds. The CoMFA model yielded a leave one out r² (r²_loo) of 0.847, non-cross-validated r² (r²_ncv) of 0.977, F value of 267.930, and bootstrapped r² (r²_bs) of 0.988. We have derived the standard error of prediction value of 0.367, standard error of estimate 0.141, and a reliable external predictivity, with a predictive r² (r²_pred) of 0.673. While the CoMSIA model yielded an r²_loo of 0.719, r²_ncv of 0.964,F value of 135.666, r²_bs of 0.975, standard error of prediction of 0.512, standard error of estimate of 0.180, and an external predictivity with an r²_pred of 0.611. These validation tests not only revealed the robustness of the models but also demonstrated that for our models r²_pred, based on the mean activity of test set compounds can accurately estimate external predictivity.

Conclusion:

The QSAR model gave satisfactory statistical results in terms of q² and r² values. We analyzed the contour maps obtained, to study the activity trends of the molecules. We have tried to demonstrate structural features of compounds to account for the activity in terms of positively contributing physicochemical properties such as steric, electrostatic, hydrophobic, hydrogen bond donor, and acceptor fields. These contour plots identified several key features, which explain the wide range of activities. The results obtained from models offer important structural insight into designing novel CCR2B antagonists before their synthesis.

Gsdma3 mutation causes bulge stem cell depletion and alopecia mediated by skin inflammation

Primary cicatricial alopecias (PCAs) are a group of permanent hair loss disorders, of which the pathogenesis is still poorly understood. The alopecia and excoriation (AE) mouse strain is a dominant mutant generated from ethyl nitrosourea mutagenesis. AE mice exhibit a progressive alopecia phenotype similar to that seen in PCAs, resulting from a point mutation in the gasdermin A3 gene. Mutant mice begin to show alopecia on the head from postnatal day 22 and experience complete hair loss by the age of 6 months, along with hyperkeratosis and catagen delay. The results of a histological examination showed that bulge stem cells in AE skin are gradually depleted, as indicated by decreased keratin 15 and CD34 expression, and reduced bromodeoxyuridine label-retaining cells in the AE bulge. In addition, AE mice display an inflammatory condition in the skin from postnatal day 7, including elevated tumor necrosis factor-α and monocyte chemotactic protein-1 mRNA levels and significantly increased macrophages and dendritic cell number. Immune privilege in the bulge was also compromised in AE skin. Consistently, after treatment with the immunosuppressive agent, cyclosporine A, immune privilege collapse, stem cell destruction, and alopecia phenotype of AE mice were all rescued. Collectively, our data demonstrate that immune-mediated destruction of bulge stem cells plays a crucial role in the pathogenesis of alopecia in AE mice, and this strain might be an interesting model for PCAs, especially for lichen planopilaris.

IL-24 transgenic mice: in vivo evidence of overlapping functions for IL-20, IL-22, and IL-24 in the epidermis

IL-20 and IL-24 share two different heterodimeric receptors consisting of either IL-20R1 or IL-22R1 and a common IL-20R2 subunit, whereas IL-22 signals through IL-22R1/IL-10R2. However, until now, only IL-20 and IL-22 have been proven to play important roles in vivo in the epidermis where all four receptor subunits are expressed. In this study, we show that IL-24 transgenic mice manifest many similar phenotypes to that of IL-20 and IL-22, including neonatal lethality, epidermal hyperplasia, and abnormality in keratinocyte differentiation. These results support a largely redundant role in epidermal functions for IL-20, IL-22, and IL-24, which seem to be IL-22R1 dependent. Moreover, we show that IL-24 transgenic mice exhibit infiltrating macrophages in the dermis with concomitant increases in MCP-1 production from both keratinocytes in the epidermis and immune infiltrates in the adjacent dermal layer below. Furthermore, we demonstrate that the homodimeric IL-20R2 soluble receptor is a potent blocker for IL-24 and can be used to further dissect the crosstalk among the IL-20 family of cytokines in normal development as well as in autoimmune diseases.

Therapeutic efficacy and immunological response of CCL5 antagonists in models of contact skin reaction

Skin-infiltrating T-cells play a predominant role in allergic and inflammatory skin diseases such as atopic dermatitis, psoriasis and allergic contact dermatitis. These T-cells are attracted by several chemotactic factors including the chemokine CCL5/RANTES, a CC chemokine inducing both the migration and activation of specific leukocyte subsets. CCL5 has been found to be associated with various cell-mediated hypersensitive disorders such as psoriasis, atopic dermatitis and irritant contact dermatitis. We have used two antagonists, the first, Met-CCL5, a dual CCR1/CCR5 antagonist and the second, a variant in which GAG binding is abrogated, ⁴⁴AANA⁴⁷-CCL5, which acts as a dominant negative inhibitor of CCL5. The antagonists were tested in two models of contact skin reaction. The first, irritant contact dermatitis (ICD) is a pathological non-specific inflammatory skin condition arising from the release of pro-inflammatory cytokines by keratinocytes in response to haptens, usually chemicals. The second, contact hypersensitivity (CHS) is a T-cell dependent model, mimicking in part the T-cell-mediated skin diseases such as psoriasis. In both models, the CCL5 antagonists showed therapeutic efficacy by reducing swelling by 50% as well as the reduction of soluble mediators in homogenates derived from challenged ears. These results demonstrate that blocking the receptor or the ligand are both effective strategies to inhibit skin inflammation.

Key role of macrophages in the pathogenesis of CD18 hypomorphic murine model of psoriasis

Psoriasis is a chronic skin disorder of unsolved pathogenesis affecting skin in 2-3% of the general population. Research into the pathogenesis of psoriasis has profited from suitable animal models. Previously, we reported on the CD18 hypomorphic (CD18(hypo)) PL/J mouse model clinically resembling human psoriasis, which is characterized by reduced expression of the common chain of beta(2)-integrins (CD11/CD18) to only 2-16% of wild-type levels. Aside from common clinical and pathophysiological features shared with human psoriasis, the psoriasiform skin disease in CD18(hypo) PL/J mice also depends on the presence of CD4(+) T-cells. This review focuses on the role of activated macrophages in the pathogenesis of CD18(hypo) T-cell-mediated mouse model of psoriasis, and extends our understanding in unrestrained pathogenic T-cells whose activation may be crucial for the recruitment and activation of macrophages within skin. The findings in the CD18(hypo) PL/J model are discussed in the context of current literatures of human and other autoimmune disorders.

The time-dependent expressions of IL-1β, COX-2, MCP-1 mRNA in skin wounds of rabbits

In this study, we investigated the time-dependent expression of IL-1beta, COX-2, MCP-1 mRNA after incised wounds in rabbit skin using real-time fluorescent quantitative PCR. The tested wound ages were distributed as following: <0.5h, 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 8h, 12h, 24h, 2d, 3d, and 7d. The expressions of three markers in postmortem wounds were determined. Comparison of each wound age with control group, expression of IL-1beta mRNA showed that the significant increase occurred at <0.5h (p<0.01), and the peak level at 2h. The expression was almost normalized at 2d. But for COX-2 and MCP-1 mRNA, the significant increase occurred at 1h for COX-2 mRNA, and 3h for MCP-1 mRNA. The expression peak levels were at 3h and 5h, and were almost normalized at 3d and 7d, respectively. There was no significant increase in all postmortem samples for IL-1beta, COX-2, MCP-1 mRNA compared with control group. Thus, the results of these cytokines and enzyme significant increase at different early wound ages implied that the combined investigation could make wound age determination more objective and accurate. Moreover, the three markers could also be used to distinguish the supravital injuries.

Downregulation of monocyte chemoattractant protein-1 involving short interfering RNA attenuates hapten-induced contact hypersensitivity

Contact hypersensitivity (CHS) is a common skin disease, presenting clinically as allergic contact dermatitis. At inflammatory sites in a typical CHS model in the mouse ear, elevated expression of monocyte chemoattractant protein-1 (MCP-1) has been reported. MCP-1 is a potent chemotactic factor for many types of leukocytes including monocytes/macrophages and T cells. In this study, we aimed at developing a therapy for CHS involving RNA interference targeting MCP-1. A short interfering RNA (siRNA) to mouse MCP-1 successfully inhibited the secretion of MCP-1 by a fibroblastic cell line, L929, and RAW 264.7 cells derived from macrophages, and strikingly suppressed ear swelling in a CHS model. The siRNA systemically administered inhibited the infiltration of both monocytes/macrophages and T cells in the CHS model. Atelocollagen was used in this therapy as a delivery reagent for siRNA into the animal body. Atelocollagen facilitated the incorporation of the siRNA into macrophages/monocytes and fibroblasts, which vigorously secrete MCP-1 protein at inflammatory sites in CHS. This therapy had no adverse effects such as induction of interferon, or liver or renal damage. Our data indicate that the systemic delivery of siRNA targeting MCP-1 is a potent therapeutic strategy for CHS treatment.

Efficacy and safety results from the randomized controlled comparative study of adalimumab vs. methotrexate vs. placebo in patients with psoriasis (CHAMPION)

BACKGROUND

Biologic therapies such as adalimumab, a tumour necrosis factor antagonist, are safe and effective in the treatment of moderate to severe chronic plaque psoriasis.

OBJECTIVES

To compare a biologic agent with methotrexate, a traditional systemic agent, to define clearly the role of biologics in psoriasis.

METHODS

Patients with moderate to severe plaque psoriasis were randomized to adalimumab (80 mg subcutaneously at week 0, then 40 mg every other week, n=108), methotrexate (7.5 mg orally, increased as needed and as tolerated to 25 mg weekly; n=110) or placebo (n=53) for 16 weeks. The primary efficacy endpoint was the proportion of patients achieving at least a 75% improvement in the Psoriasis Area and Severity Index (PASI 75) after 16 weeks. Safety was assessed at all visits through week 16.

RESULTS

After 16 weeks, 79.6% of adalimumab-treated patients achieved PASI 75, compared with 35.5% for methotrexate (P<0.001 vs. adalimumab) and 18.9% for placebo (P<0.001 vs. adalimumab). Statistically significantly more adalimumab-treated patients (16.7%) than methotrexate-treated patients (7.3%) or placebo-treated patients (1.9%) achieved complete clearance of disease. The response to adalimumab was rapid, with a 57% improvement in mean PASI observed at week 4. Adverse events were similar across treatment groups. Adverse events leading to study discontinuation were greatest in the methotrexate group, primarily because of hepatic-related adverse events.

CONCLUSIONS

After 16 weeks, adalimumab demonstrated significantly superior efficacy and more rapid improvements in psoriasis compared with either methotrexate or placebo.

The evolution of the psoriatic lesion

Psoriasis comprises a host of abnormalities, and various aspects of the pathogenesis of psoriasis have been suggested to be of primary relevance. The aim of this review is to identity driving factors in the pathogenesis of psoriasis and to explore the dynamics of processes eventually resulting in a psoriatic lesion. In this review observations on the evolution from the symptomless skin to lesional skin in patients with psoriasis will be integrated with observations in various animal models of psoriasis.

Effect of matrine on the expression of substance P receptor and inflammatory cytokines production in human skin keratinocytes and fibroblasts

Matrine is a kind of alkaloid found in certain Sophora plants, which has been extensively used in China for the treatment of viral hepatitis, cancer, cardiac diseases and skin diseases (such as atopic dermatitis and eczema). It also has been confirmed that substance P (SP) and its receptor (neurokinin-1 receptor, NK-1R) are involved in the pathogenesis of inflammatory skin disorders. So the present study was designed to investigate the effect of matrine on the expression of NK-1R and cytokines production induced by SP in HaCaT cells (a human epidermal keratinocyte cell line) and dermal fibroblasts. In addition, cell viability was also evaluated. The results showed that matrine inhibited the expression of NK-1R in HaCaT cells and fibroblasts. SP induced the production of interleukin (IL)-1beta, IL-8, interferon (IFN)-gamma, and monocyte chemotactic protein (MCP)-1 in both cell types. Matrine 5-100 microg/mL had little effect on cell viability. It inhibited SP-induced IL-1beta, IL-8 and MCP-1 production in HaCaT cells and fibroblasts, while it increased the production of IFN-gamma in HaCaT cells. Both SP and matrine had no effect on the secretion of IL-6. These findings suggest that matrine may have potential treatment function on SP related cutaneous inflammation by inhibition of the expression of substance P receptor and regulation of the production of inflammatory cytokines.

Interferon-gamma is causatively involved in experimental inflammatory bowel disease in mice

Cytokines may be crucially involved in the pathogenesis of inflammatory bowel diseases (IBD), but it remains controversial whether interferon (IFN)-gamma, a typical proinflammatory cytokine, is an essential mediator to cause the disorders. In the present study, IFN-gamma(-/-) and wild-type (WT) C57BL/6 mice were fed 2.5% dextran sodium sulphate (DSS) in drinking water for 7 days, in order to investigate DSS-induced intestinal inflammation. The DSS-treated WT mice exhibited a robust production of IFN-gamma in the gut, a remarkable loss of body weight, as well as high rate of mortality (60%). In striking contrast, IFN-gamma deficient mice did not develop DSS-induced colitis, as indicated by the maintenance of body weight and survival rate of 100%. Severe intestinal inflammation was demonstrated exclusively in WT animals in terms of the shortening of the bowel as well as the elevation of the disease activity index, myeloperoxidase (MPO) activity and serum haptoglobin level. Histological study of DSS-treated WT intestine revealed disruption of mucosal epithelium and massive infiltration of inflammatory cells, while the organ from IFN-gamma(-/-) mice remained virtually normal in appearance. Enzyme-linked immunosorbent assay (ELISA) analyses indicated abundant production of three chemokines, i.e. monokine induced by interferon-gamma (MIG), interferon-inducible protein 10 (IP-10) and monocyte chemoattractant protein-1 (MCP-1), in the DSS-irritated intestine of WT but not of IFN-gamma(-/-) mice. The present results demonstrate clearly that IFN-gamma plays indispensable roles in the initiation of DSS colitis, and some chemokines are produced in an IFN-gamma-dependent fashion.