Nature of cell kinetics in psoriatic epidermis

Brilaroxazine lipogel displays antipsoriatic activity in imiquimod-induced mouse model

BACKGROUND

Dopamine (D) and serotonin (5-HT) pathways contribute to psoriasis pathobiology. Disruptions incite increased inflammatory mediators, keratinocyte activation and deterioration, and worsening symptoms. Brilaroxazine (RP5063), which displays potent high binding affinity to D2/3/4 and 5-HT1A/2A/2B/7 receptors and a moderate affinity to serotonin transporter (SERT), may affect the underlying psoriasis pathology.

METHODS

An imiquimod-induced psoriatic mouse model (BALB/c) evaluated brilaroxazine's activity in a topical liposomal-aqueous gel (Lipogel) formulation. Two of the three groups (n = 6 per) underwent induction with 5% imiquimod, and one group received topical brilaroxazine Lipogel (Days 1-11). Assessments included (1) Psoriasis Area and Severity Index (PASI) scores (Days 1-12), skin histology for Baker score based on H&E stained tissue (Day 12), and serum blood collection for serum cytokine analysis (Day 12). One-way ANOVA followed by post hoc Dunnett's t-test evaluated significance (p < 0.05).

RESULTS

Imiquimod-induced animal Baker scores were higher versus Sham non-induced control's results (p < 0.001). Brilaroxazine Lipogel had significantly (p = 0.003) lower Baker scores versus the induced Psoriasis group. Brilaroxazine PASI scores were lower (p = 0.03) versus the induced Psoriasis group (Days 3-12), with the greatest effect in the last 3 days. The induced Psoriasis group showed higher Ki-67 and TGF-β levels versus non-induced Sham controls (p = 0.001). The brilaroxazine Lipogel group displayed lower levels of these cytokines versus the induced Psoriasis group, Ki-67 (p = 0.001) and TGF-β (p = 0.008), and no difference in TNF-α levels versus Sham non-induced controls.

CONCLUSION

Brilaroxazine Lipogel displayed significant activity in imiquimod-induced psoriatic animals, offering a novel therapeutic strategy.

Individualised computational modelling of immune mediated disease onset, flare and clearance in psoriasis

Despite increased understanding about psoriasis pathophysiology, currently there is a lack of predictive computational models. We developed a personalisable ordinary differential equations model of human epidermis and psoriasis that incorporates immune cells and cytokine stimuli to regulate the transition between two stable steady states of clinically healthy (non-lesional) and disease (lesional psoriasis, plaque) skin. In line with experimental data, an immune stimulus initiated transition from healthy skin to psoriasis and apoptosis of immune and epidermal cells induced by UVB phototherapy returned the epidermis back to the healthy state. Notably, our model was able to distinguish disease flares. The flexibility of our model permitted the development of a patient-specific “UVB sensitivity” parameter that reflected subject-specific sensitivity to apoptosis and enabled simulation of individual patients’ clinical response trajectory. In a prospective clinical study of 94 patients, serial individual UVB doses and clinical response (Psoriasis Area Severity Index) values collected over the first three weeks of UVB therapy informed estimation of the “UVB sensitivity” parameter and the prediction of individual patient outcome at the end of phototherapy. An important advance of our model is its potential for direct clinical application through early assessment of response to UVB therapy, and for individualised optimisation of phototherapy regimes to improve clinical outcome. Additionally by incorporating the complex interaction of immune cells and epidermal keratinocytes, our model provides a basis to study and predict outcomes to biologic therapies in psoriasis.

We present a new computer model for psoriasis, an immune-mediated disabling skin disease which presents with red, raised scaly plaques that can appear over the whole body. Psoriasis affects millions of people in the UK alone and causes significant impairment to quality of life, and currently has no cure. Only a few treatments (including UVB phototherapy) can induce temporary remission. Despite our increased understanding about psoriasis, treatments are still given on a ‘trial and error’ basis and there are no reliable computer models that can a) elucidate the mechanisms behind psoriasis onset or flare and b) predict a patient’s response to a course of treatment (e.g., phototherapy) and the likelihood of inducing a period of remission. Our computer model addresses both these needs. First, it explicitly describes the interaction between the immune system and skin cells. Second, our model captures response to therapy at the individual patient level and enables personalised prediction of clinical outcomes. Notably, our model also supports prediction of amending individual UVB phototherapy regimes based on the patient’s initial response that include for example personalised delivery schedules (i.e., 3x weekly vs. 5x weekly phototherapy). Therefore, our work is a crucial step towards precision medicine for psoriasis treatment.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

HSP90 inhibitor RGRN-305 for oral treatment of plaque type psoriasis: efficacy, safety and biomarker results in an open-label proof-of-concept study

BACKGROUND

HSP90 is a downstream regulator of tumor necrosis factor α (TNFα) and interleukin (IL)-17A signaling and may therefore serve as a novel target in the treatment of psoriasis.

OBJECTIVE

This phase 1b proof-of-concept study was undertaken to evaluate the safety and efficacy of a novel HSP90 inhibitor (RGRN-305) in the treatment of plaque psoriasis.

METHODS

An open-label, single-arm, dose-selection, single-center proof-of-concept study. Patients with plaque psoriasis were treated with 250 mg or 500 mg RGRN-305 daily for 12 weeks. Efficacy was evaluated clinically using Psoriasis Area and Severity Index (PASI), body surface area (BSA), and Physician Global Assessment (PGA) scores and by Dermatology Life Quality Index (DLQI). Skin biopsies collected at baseline and at 4, 8, and 12 weeks after treatment start were used for immunohistochemical staining and for gene expression analysis. Safety was monitored via laboratory tests, vital signs, ECG, and physical examinations.

RESULTS

Six of the eleven patients completing the study responded to RGRN-305 with a PASI improvement between 71% and 94%, whereas five patients were considered nonresponders with a PASI response < 50%. No severe adverse events were reported. Four of seven patients treated with 500 mg RGRN-305 daily experienced a mild to moderate exanthematous drug induced eruption due to study treatment. Two patients chose to discontinue the study due to this exanthematous eruption. RGRN-305 treatment resulted in pronounced inhibition of the IL-23, TNFα, and IL-17A signaling pathways and normalization of both histological changes and psoriatic lesion gene expression profiles in patients responding to treatment.

CONCLUSION

Treatment with RGRN-305 showed an acceptable safety, especially in the low-dose group, and was associated with clinically meaningful improvement in a subset of patients with plaque psoriasis, indicating that HSP90 may serve as a novel future target in psoriasis treatment.

Blood Metagenome in Health and Psoriasis

A survey and analytical assessment of the results of fundamental works on studying blood metagenome (set of all non-human DNA) is carried out. All works on determining bacterial DNA concentration in the whole blood of healthy people are reviewed. Detailed comparison of characteristics of 16S rRNA test (hereinafter 16S-test) and whole metagenome sequencing test (hereinafter WMS-test) is carried out and published in Supplement S1. One of main goals of this review is to identify the drawbacks and mistakes which the studied works contain, particularly to emphasize the crucial importance of determining total concentration of bacterial DNA for comparing patients' metagenomes with those of healthy people as well as for comparing patients' metagenomes with each other. Controlling the level and composition of contamination is equally important. The absence of high-quality contamination control at each step (or at certain steps) of the research significantly reduces the reliability of achieved results. The given review is the first attempt to analyze and systematize the results of blood metagenome studies, whose number has increased considerably in the last few years. The review has been carried out as part of preparation for implementing a project on complex studying metagenomes of whole blood and skin biopsies of psoriatic patients.

Immunohistochemical expression of P53, Ki-67, and CD34 in psoriasis and psoriasiform dermatitis

BACKGROUND

Psoriasis is the prime example of psoriasiform tissue pattern and should be differentiated from other psoriasiform dermatoses both clinically and histopathologically.

AIM

To evaluate immunohistochemical expression of P53, Ki-67, and CD34 in psoriasis and psoriasiform dermatitis for diagnostic purposes.

METHODS

An analytical cross-sectional study was performed on the paraffin blocks of 60 psoriasis and 31 psoriasiform dermatitis patients between 2014 and 2017. The selected formalin-fixed paraffin-embedded tissues from each biopsy specimen were cut into 4-micron sections. Initial sections were stained by hematoxylin and eosin staining. Primary antihuman antibodies against P53, Ki-67, and CD34 were applied. Positive control samples for biomarkers were received from former strongly positive samples of papillary endothelial hyperplasia, high grade lymphoma, and breast ductal carcinoma for CD34, Ki-67, and P53, respectively.

RESULTS

Out of 60 psoriasis patients, 56.7% were men, with the mean age of 36.8 years. From 31 psoriasiform patients, 45.2% were men, with the mean age of 37.5 years. Both groups were matched in terms of sex and age. The mean staining of three markers was more significant in psoriasiform dermatitis than psoriasis.

CONCLUSION

In spite of some other researches, the present study showed expression of P53, Ki-67, and CD34 biomarkers were significantly higher in psoriasiform dermatitis than psoriasis.

MCM3: A Novel Proliferation Marker in Oral Squamous Cell Carcinoma

The present study sought to evaluate and compare the immunoexpression of proteins minichromosome maintenance (MCM) 3 and Ki-67 in oral squamous cell carcinoma (OSCC) to assess the potential of these proteins as markers of cellular proliferation. Twenty-eight cases of OSCC, 9 of tumor-free resection margins (TM), and 4 of non-neoplastic oral mucosa (NNM) were subjected to immunohistochemistry to detect the expression of proteins MCM3 and Ki-67. All OSCCs demonstrated positivity for both proteins. In these tumors, greater MCM3 immunoreactivity was observed in comparison with Ki-67, whereas TMs and NNMs exhibited greater Ki-67 expression compared with MCM3. The immunoexpression of Ki-67 seemed to be influenced by the inflammatory process, particularly in TM and NNM. Our findings indicate that although both MCM3 and Ki-67 represent reliable markers of cellular proliferation in OSCC, as MCM3 expression does not appear to be influenced by external factors, this protein may emerge as a novel marker of cellular proliferation in these types of tumors.

Cellular Interactions in Vitro: Psoriatic Keratinocytes Enhance T Lymphocyte Survival

Background

The pathogenesis of psoriasis vulgaris is attributed to an immune dysregulation of T lymphocytes, and psoriatic plaques result from interactions between keratinocytes and T lymphocytes.

Objective

To decipher the impact of keratinocyte-T lymphocyte interactions on cell survival during active cutaneous psoriasis by using a new in vitro model of psoriasis.

Methods

Cocultures of psoriatic or healthy keratinocytes were performed with normal human blood T lymphocytes. Apoptosis was detected by flow cytometry after labeling cells with annexin V and propidium iodide.

Results

Psoriatic keratinocytes were significantly more efficient than healthy keratinocytes in enhancing T lymphocyte survival.

Conclusion

Our in vitro model is pertinent to understanding the immunopathogenesis of psoriasis and to discovering new pharmacological targets.

BAY 11-7082 inhibits the NF-κB and NLRP3 inflammasome pathways and protects against IMQ-induced psoriasis

BAY 11-7082 antagonizes I-κB kinase-β preventing nuclear translocation of nuclear factor-κB (NF-κB); it also inhibits NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation. NF-κB is involved in psoriasis, whereas the role of NLRP3 is controversial. We investigated BAY 11-7082 effects in an experimental model of psoriasis-like dermatitis. Psoriasis-like lesions were induced by a topical application of imiquimod (IMQ) cream (62.5 mg/day) on the shaved back skin of C57BL/6 and NLRP3 knockout (KO) mice for 7 consecutive days. Sham psoriasis animals were challenged with Vaseline cream. Sham and IMQ animals were randomized to receive BAY 11-7082 (20 mg/kg/i.p.) or its vehicle (100 μl/i.p of 0.9% NaCl). Skin of IMQ animals developed erythema, scales, thickening and epidermal acanthosis. IMQ skin samples showed increased expression of pNF-κB and NLRP3 activation. BAY 11-7082 blunted epidermal thickness, acanthosis and inflammatory infiltrate. BAY 11-7082 reduced pNF-κB, NLRP3, tumour necrosis factor-α (TNF-α), interleukin (IL)-6 and IL-1β expression, blunted the phosphorylation of signal transducer and activators of transcription 3 (STAT3) and decreased IL-23 levels. In addition, BAY 11-7082 reawakened the apoptotic machinery. NLRP3 KO animals showed a reduced total histological score but persistent mild acanthosis, dermal thickness and expression of pNF-κB and pSTAT3, following IMQ application. Our data suggest that BAY 11-7082 might represent an interesting approach for the management of psoriasis-like dermatitis depending on the dual inhibition of NF-κB and NLRP3.

Methotrexate treatment provokes apoptosis of proliferating keratinocyte in psoriasis patients

Psoriasis is a chronic inflammatory skin disease characterized by hyper proliferation of keratinocytes. Recent data show that the epidermis thickening in psoriasis may be related to imbalance of homeostasis caused by abnormal apoptotic process. Maintenance of keratinocyte apoptotic process is very important in psoriasis. Methotrexate (MTX) has been used for many years to restore the normal skin in psoriasis condition. However, the exact mechanism of MTX in psoriasis condition is poorly understood. The aim of this study was to examine the role of MTX on keratinocyte apoptosis pathway in psoriasis patients. A total of 58 psoriasis vulgaris patients were recruited for this study. Nonlesional skin biopsies served as control. Skin biopsies of psoriatic patients were collected and analyzed for cytosolic, mitochondria and total cytochrome c by ELISA. Expression of caspase-9, NFκBp65, pAkt1 by western blot, real-time PCR and immunohistochemical analysis of c-FLIP protein was analyzed in nonlesional and lesional skin biopsies before (day 0) and after (at the end of 6 and 12 weeks) MTX treatment. After MTX treatment, a significant increase in cytochrome c was observed when compared with before MTX treatment in psoriasis patients (p < 0.001). Protein and gene expression of cleaved caspase-9 were significantly increased after MTX treatment, whereas the expression of Bcl-xL, c-FLIP, NFκBp65, pAkt1 significantly downregulated after MTX treatment. In conclusion, these results showed that intrinsic apoptotic pathway induced by MTX eventually adds the beneficial therapeutic role of MTX in psoriasis by controlling the acanthosis.

Modelling epidermis homoeostasis and psoriasis pathogenesis

We present a computational model to study the spatio-temporal dynamics of epidermis homoeostasis under normal and pathological conditions. The model consists of a population kinetics model of the central transition pathway of keratinocyte proliferation, differentiation and loss and an agent-based model that propagates cell movements and generates the stratified epidermis. The model recapitulates observed homoeostatic cell density distribution, the epidermal turnover time and the multilayered tissue structure. We extend the model to study the onset, recurrence and phototherapy-induced remission of psoriasis. The model considers psoriasis as a parallel homoeostasis of normal and psoriatic keratinocytes originated from a shared stem cell (SC) niche environment and predicts two homoeostatic modes of psoriasis: a disease mode and a quiescent mode. Interconversion between the two modes can be controlled by interactions between psoriatic SCs and the immune system and by normal and psoriatic SCs competing for growth niches. The prediction of a quiescent state potentially explains the efficacy of multi-episode UVB irradiation therapy and recurrence of psoriasis plaques, which can further guide designs of therapeutics that specifically target the immune system and/or the keratinocytes.

Diagnostic utility of Ki-67 and Cyclin D1 immunostaining in differentiation of psoriasis vs. other psoriasiform dermatitis

Background:

Differentiation of psoriasis from non-psoriasis psoriasiform dermatitis (NPPD) may be difficult for dermatopathologists, as lack of distinctive histopathological features in a subset of cases may cause confusion in diagnosis.

Objective:

As the prototype of psoriasiform dermatitis, psoriasis is a hyperproliferative skin disorder with increased epidermal turnover compared with NPPD, we investigated the role of proliferation markers, Ki-67 and Cyclin D1 as diagnostic tools to differentiate psoriasis from other psoriasiform dermatitis.

Methods:

Histopathological specimens of psoriasis (n = 35) and NPPD (n = 36, 14 pityriasis rubra pilaris, 12 pityriasis rosea and 10 lichen simplex) cases were reviewed and immunohistochemically stained for Ki-67 and Cyclin D1. Ki-67 and Cyclin D1 positive cells were counted for suprabasal, and total epidermal immunostaining per mm².

Results:

Suprabasal and total epidermal cell counts for Ki-67 were found to be significantly higher in the psoriasis group compared with the NPPD group (p < 0.05). An important and interesting feature was the presence of a cut-off value for the suprabasal/total epidermal cell count ratio of 75% for Ki-67 immunostaining, which was higher in all patients having psoriasis (range, 77.1% – 92.4%) and lower in all NPPD cases (range, 21.0% – 73.3%). However, suprabasal Cyclin D1 cell counts were higher in the psoriasis group compared with the NPPD group (p < 0.05), total epidermal Cyclin D1 cell counts were not statistically significant in either group (p = 0.167), and a cut-off value for suprabasal/total epidermal cell count ratio to distinguish these two entities was not detected using this immunostain.

Conclusions:

We suggest that Ki-67 is a more sensitive marker than Cyclin D1 in terms of having a cutoff value of 75% for the suprabasal/total epidermal immunoreactive cell count ratio, which we believe could be useful for dermatopathologists in differentiating psoriasis from other psoriasiform dermatitis.

Aquaporin-3-mediated hydrogen peroxide transport is required for NF-κB signalling in keratinocytes and development of psoriasis

Aquaporin 3 (AQP3), a water/glycerol channel protein, has been found to transport hydrogen peroxide (H2O2). Here, we show that H2O2, imported via AQP3, is involved in nuclear factor-κB (NF-κB) signalling in keratinocytes and in the pathogenesis of psoriasis. IL-23-mediated induction of psoriasis is reduced in AQP3 knockout mice (AQP3(-/-)), and is accompanied by impaired NF-κB activation and intracellular H2O2 accumulation. In primary keratinocyte cultures, cellular import of H2O2 produced by membrane NADPH oxidase 2 (Nox2) in response to TNF-α is facilitated by AQP3 and required for NF-κB activation by regulation of protein phosphatase 2A. As AQP3 associates with Nox2, we propose that this interplay constitutes H2O2-mediated signalling in response to TNF-α stimulation. Collectively, these data indicate that AQP3-facilitated H2O2 transport is required for NF-κB activation in keratinocytes in the development of psoriasis.

Portulaca oleracea L. aids calcipotriol in reversing keratinocyte differentiation and skin barrier dysfunction in psoriasis through inhibition of the nuclear factor κB signaling pathway

Psoriasis affects 2-4% of the population worldwide and its treatment is currently far from satisfactory. Calcipotriol and Portulaca oleracea have been reported to exhibit the capacity to inhibit inflammation in psoriatic patients and improve their clinical condition. However, the efficacy of a combination regimen of these two components remains unknown. The aim of the present study was to explore the therapeutic efficacy of P. oleracea extract combined with calcipotriol on plaque psoriasis and its potential mechanism. Eleven patients with plaque psoriasis were treated with humectant containing the active ingredients of P. oleracea extract, with or without 0.005% calcipotriol ointment in a right-left bilateral lesion self-control study. Differences were evaluated by investigation of the clinical efficacy, adverse effects, skin barrier function, histological structure, expression and proliferation of keratinocytes, differentiation markers (cytokeratin 10, filaggrin and loricrin), inflammatory factors [tumor necrosis factor (TNF)-α and interleukin (IL)-8], as well as the status of the nuclear factor κB (NF-κB) pathway. The combination of P. oleracea and calcipotriol was revealed to decrease adverse effects, reduce transepidermal water loss, potently reverse keratinocyte differentiation dysfunction, and inhibit the expression of TNF-α and IL-8 and the phosphorylation of the NF-κB inhibitor IκBα. This treatment is therefore anticipated to be suitable for use as a novel adjuvant therapy for psoriatic patients.

Omentin serum levels and omentin gene Val109Asp polymorphism in patients with psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease of uncertain pathogenesis. Omentin is a new adipokine with anti-inflammatory properties; however, the relationship between psoriasis and omentin has not been fully established yet.

OBJECTIVES

This study was designed to evaluate the relationship between psoriasis and omentin serum levels and Val109Asp polymorphism in exon 4 of the omentin gene.

METHODS

Forty-nine patients with plaque-type psoriasis and 39 healthy subjects were included in the study. Omentin concentrations were determined by using enzyme-linked immunosorbent assay. Val109Asp polymorphism in exon 4 of the omentin gene was assessed by the polymerase chain reaction-restriction fragment length polymorphism method. Genotypes were determined according to the bands formed in agarose electrophoresis gels. In the statistical analysis, the level of significance was set at P < 0.05.

RESULTS

The serum omentin levels of the patients with psoriasis (354.2 ± 152.0) were found to be significantly lower than those in the control group (488.7 ± 190.3) (P = 0.001). A moderate level negative correlation was determined between serum omentin level and body mass index and waist circumference. No significant differences were observed between the patient and control groups in terms of the genotype and allele frequency of Val109Asp polymorphism in exon 4 of the omentin gene (P > 0.05).

CONCLUSIONS

Omentin serum levels were determined to be low in patients with psoriasis. No significant difference was found regarding Val109Asp polymorphism of the omentin gene. To the best of our knowledge, our study is the first clinical study to examine the relationship between psoriasis and omentin in terms of serum and genomic levels.

The relationship between severity of the disease and circulating nucleosomes in psoriasis patients

Psoriasis was initially considered to represent a disease of abnormal epidermal keratinocyte proliferation. Proliferation of keratinocytes is restricted by apoptotic cell death to maintain a constant thickness of epidermis. Nucleosomes are mainly released by apoptotic cells. Tumor necrosis factor-α (TNF-α) is an important factor affecting the apoptosis. In the present study, the relationship between TNF-α, nucleosome and the Psoriasis Area and Severity Index (PASI) score was investigated. The patients were divided according to PASI score into three groups (mild, moderately, severe). Serum TNF-α and nucleosome levels were measured using Enzyme-linked immunosorbent assay (ELISA) method. Our findings show a correct relationship between PASI scores and TNF-α and an inverse relationship between nucleosome and PASI score. According to the results obtained from the study, we believe that serum nucleosome levels can be used as a new indicator in follow-up of patients with psoriasis and monitoring of the effectiveness of drugs which used in the treatment of psoriasis.

Expression of nuclear factor kappa B and survivin in psoriasis

Background and Objective. Suppression of apoptosis has been proposed as a mechanism responsible for epidermal thickness in psoriasis. Survivin is a member of the inhibitor of apoptosis family. Nuclear factor kappa B (NF-κB) is one of the transcriptional factors that regulate many genes affecting apoptosis. The aim of this study was to determine survivin and NF-κB expressions in psoriasis in comparison with normal epidermis. Patients and Methods. Immunohistochemical expressions of survivin and NF-κB were investigated in 41 psoriatic and 21 normal skin samples. Results. Diffuse nuclear survivin expression in all epidermal layers was seen in all of the psoriatic samples. NF-κB expression in different epidermal locations was seen in all of the psoriatic samples. Nuclear staining was positive in 40 psoriasis samples. Similar survivin and NF-κB expressions were observed in normal skin samples. Conclusion. Since similar expressions are seen in both normal and psoriatic epidermis, no important roles for survivin and NF-κB can be attributed in epidermal proliferation and thickness seen in psoriasis.

Anti-apoptotic effects of suppressor of cytokine signaling 3 and 1 in psoriasis

Because of their genetically determined capacity to respond to pro-inflammatory stimuli, keratinocytes have a crucial role in the pathogenesis of psoriasis. Upon IFN-γ and TNF-α exposure, psoriatic keratinocytes express exaggerated levels of inflammatory mediators, and show aberrant hyperproliferation and terminal differentiation. The thickening of psoriasic skin also results from a peculiar resistance of keratinocytes to cytokine-induced apoptosis. In this study, we investigated on the molecular mechanisms concurring to the resistance of psoriatic keratinocytes to cell death, focusing on the role having suppressor of cytokine signaling (SOCS)1 and SOCS3, two molecules abundantly expressed in IFN-γ/TNF-α-activated psoriatic keratinocytes, in sustaining anti-apoptotic pathways. We found that SOCS1 and SOCS3 suppress cytokine-induced apoptosis by sustaining the activation of the PI3K/AKT pathway in keratinocytes. The latter determines the activation of the anti-apoptotic NF-κB cascade and, in parallel, the inhibition of the pro-apoptotic BAD function in keratinocytes. For the first time, we report that phosphorylated AKT and phosphorylated BAD are strongly expressed in lesional psoriatic skin, compared with healthy or not lesional skin, and they strictly correlate to the high expression of SOCS1 and SOCS3 molecules in the psoriatic epidermis. Finally, the depletion of SOCS1 and SOCS3, as well as the chemical inactivation of PI3K activity in psoriatic keratinocytes, definitively unveils the role of PI3K/AKT cascade on the resistance of diseased keratinocytes to apoptosis.

Chronic Proliferative Dermatitis in Mice: NFκB Activation Autoinflammatory Disease

Autoinflammatory diseases are a heterogeneous group of congenital diseases characterized by the presence of recurrent inflammation, in the absence of infectious agents, detectable autoantibodies or antigen-specific autoreactive T-cells. SHARPIN deficient mice presents multiorgan chronic inflammation without known autoantibodies or autoreactive T-cells, designated Sharpin(cpdm). Histological studies demonstrated epidermal hyperproliferation, Th-2 inflammation, and keratinocyte apoptosis in this mutant. The mutant mice have decreased behavioral mobility, slower growth, and loss of body weight. Epidermal thickness and mitotic epidermal cells increase along with disease development. K5/K14 expression is distributed through all layers of epidermis, along with K6 expression in interfollicular epidermis, suggesting epidermal hyperproliferation. K1/K10 is only detectable in outer layers of spinosum epidermis, reflecting accelerated keratinocyte migration. Alpha smooth muscle actin is overexpressed in skin blood vessels, which may release the elevated white blood cells to dermis. CD3(+)CD45(+) cells and granulocytes, especially eosinophils and mast cells, aggregate in the mutant skin. TUNEL assay, together with Annexin-V/propidium iodide FACS analysis, confirmed the increase of apoptotic keratinocytes in skin. These data validate and provide new lines of evidence of the proliferation-inflammation-apoptosis triad in Sharpin(cpdm) mice, an NFκB activation autoinflammatory disease.

The anti-apoptotic protein G1P3 is overexpressed in psoriasis and regulated by the non-coding RNA, PRINS

Psoriasis Susceptibility-Related RNA Gene Induced by Stress (PRINS) is a non-coding RNA overexpressed in lesional and non-lesional psoriatic epidermis and induced by stress. Its function in healthy and psoriatic skin is still not known. Here, we report that PRINS regulates G1P3, a gene with anti-apoptotic effects in keratinocytes. siRNA-mediated inhibition of PRINS gene resulted in altered cell morphology and gene expression alterations, as demonstrated in a microarray experiment. One of the genes regulated by PRINS ncRNA was G1P3, an interferon-inducible gene with anti-apoptotic effects in cancer cells. Interestingly, we found that G1P3 was 400-fold upregulated in hyperproliferative lesional and ninefold upregulated in non-lesional psoriatic epidermis compared to healthy epidermis. In vitro, G1P3 protein levels were highest in proliferating keratinocytes and siRNA-mediated downregulation of G1P3 resulted in increased cell apoptosis. These data indicate that G1P3 inhibits spontaneous keratinocyte apoptosis and hence its high expression in psoriatic skin may contribute to the development of psoriatic lesions. We hypothesize that the deregulation of the PRINS ncRNA may contribute to psoriasis and results in decreased sensitivity to spontaneous keratinocyte apoptosis via the regulation of G1P3.

Ezrin, maspin, peroxiredoxin 2, and heat shock protein 27: potential targets of a streptococcal-induced autoimmune response in psoriasis

Psoriasis is an HLA-Cw6-associated T cell-mediated autoimmune disease of the skin that is often triggered by streptococcal angina. To identify keratinocyte proteins, which may become psoriatic autoantigens as the result of an immune response against streptococci, rabbits were immunized with heat-killed Streptococcus pyogenes. Streptococcal immunization induced Ab formation against various human keratinocyte proteins. Sera from psoriasis patients reacted against several of these proteins as well. Common serologic reactivities of rabbits and patients included the proteins ezrin, maspin, peroxiredoxin 2 (PRDX2), heat shock protein (hsp)27, and keratin 6. When used for stimulation of blood lymphocytes, ezrin, maspin, PRDX2, and hsp27 induced increased T cell activation in psoriasis patients, which was particularly evident for HLA-Cw6(+) individuals. Ag-specific T cell lines generated with these proteins consisted predominantly of CD8(+) T cells and used TCR beta-chain rearrangements, which were highly homologous to those expanded within the corresponding skin lesion. Several immunodominant epitopes on the different proteins could be defined according to sequence alignments with the whole genome of S. pyogenes. Our data indicate that maspin, ezrin, PRDX2, hsp27, and potentially keratin 6 could act as autoantigens of a streptococcal-induced autoimmune response and represent targets of the exaggerated T cell response in psoriasis. Additionally, ezrin and hsp27 might constitute antigenic links between psoriasis and inflammatory bowel disease, uveitis, or arteriosclerosis, which are clinically associated.

Evaluation of survivin and NF-kappaB in psoriasis, an immunohistochemical study

BACKGROUND

Suppression of apoptosis is generally one of the accepted pathogenetic mechanisms for psoriasis and any epidermal hyperproliferative states. Survivin is a member of the inhibitor of apoptosis protein family mediating its apoptosis suppressive function by the inhibition of caspase pathway. Nuclear factor kappa B (NF-kappaB) is a transcription factor that regulates hundreds of genes including many critically involved in apoptosis. The aim of this study was to explore the role could be played by survivin and NF-kappaB in psoriasis and the link between them.

METHODS

Thirty cases of lesional psoriasis, 10 perilesional and 10 control specimens from normal skin were studied by immunohistochemical method for expression of survivin and NF-kappaB.

RESULTS

Survivin was detected in 73% of psoriatic lesions distributed either in epidermis, in endothelial cells of proliferating capillaries or in both of them. In non-psoriatic lesions either perilesional or control specimens, survivin was confined to basal layer of epidermis, significantly up regulated in psoriasis in comparison with non-psoriatic lesions (p = 0.0001). Nuclear expression of NF-kappaB was detected in 66% of psoriatic lesions; this active phosphorylated form was significantly over expressed in psoriasis in comparison with normal skin (p = 0.0004). Diffuse nuclear expression of NF-kappaB was significantly associated with up-regulation of survivin in psoriatic plaque (p = 0.03).

CONCLUSIONS

Survivin and NF-kappaB appeared to be important factors in the pathogenesis of psoriasis. Survivin could be the target of NF-kappaB mediating its death signal inhibition pathway in psoriasis.