Psoriasis as Autoinflammatory Disease

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

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

Knowledge Mapping and Research Hotspots of Comorbidities in Psoriasis: A Bibliometric Analysis from 2004 to 2022

Background and Objectives: Psoriasis is a chronic inflammatory disease whose impact on health is not only limited to the skin, but is also associated with multiple comorbidities. Early screening for comorbidities along with appropriate treatment plans can provide a positive prognosis for patients. This study aimed to summarize the knowledge structure in the field of psoriasis comorbidities and further explore its research hotspots and trends through bibliometrics. Materials and Methods: A search was conducted in the core collection of the Web of Science for literature on comorbidities of psoriasis from 2004 to 2022. VOSviewer and CiteSpace software were used for collaborative network analysis, co-citation analysis of references, and keyword co-occurrence analysis on these publications. Results: A total of 1803 papers written by 6741 authors from 81 countries was included. The publications have shown a progressive increase since 2004. The United States and Europe were at the forefront of this field. The most prolific institution was the University of California, and the most productive author was A. Armstrong. Research has focused on "psoriatic arthritis", "metabolic syndrome", "cardiovascular disease", "psychosomatic disease", "inflammatory bowel disease", "prevalence", "quality of life", and "risk factor" in the past 18 years. Keywords such as "biologics" and "systemic inflammation", have been widely used recently, suggesting current research hotspots and trends. Conclusions: Over the past 18 years, tremendous progress has been made in research on psoriasis comorbidity. However, collaborations among countries, institutions, and investigators are inadequate, and the study of the mechanisms of interaction between psoriasis and comorbidities and management of comorbidities is insufficient. The treatment of comorbidities with biologic agents, screening of comorbidities, and multidisciplinary co-management are predicted to be the focus of future research.

Efficacy and safety of curcumin in psoriasis: preclinical and clinical evidence and possible mechanisms

Background: Psoriasis is a chronic and immune-mediated inflammatory skin disease. Many studies have shown that curcumin (CUR) has strong anti-inflammatory effects and can improve psoriasis; however, its efficacy and safety have not been confirmed, and the specific mechanism remains to be elucidated.

Objective: To evaluate the efficacy, safety, and possible mechanisms of CUR in the treatment of psoriasis.

Methods: The Cochrane Library, Embase, PubMed, Web of Science, China National Knowledge Infrastructure, Wanfang, and VIP (China Science and Technology Journal Database) were systematically searched for clinical trials and preclinical studies on the use of CUR in psoriasis treatment. All databases were searched from inception to January 2022. The meta-analysis was performed using RevMan 5.3 software.

Results: Our meta-analysis included 26 studies, comprising seven clinical randomized controlled trials and 19 preclinical studies. A meta-analysis of clinical trials showed that both CUR monotherapy and combination therapy improved Psoriasis Area and Severity Index (PASI) scores in patients compared to controls (standard mean difference [std.MD]: −0.83%; 95% confidence interval [CI]: −1.53 to 0.14; p = 0.02). In preclinical studies, CUR showed better performance in improving the phenotype of psoriatic dermatitis mice compared to controls, including total PASI score (std.MD: 6.50%; 95% CI: 10.10 to −2.90; p = 0.0004); ear thickness (p = 0.01); and the expression of inflammatory cytokines such as interleukin (IL)-17, tumor necrosis factor (TNF)-α, IL-17F, and IL-22 (p < 0.05). In cell studies, CUR inhibited cell proliferation (p = 0.04) and the cell cycle (p = 0.03) and downregulated the inflammatory cytokines IL-6 and IL-8 (p < 0.05).

Conclusions: CUR has excellent efficacy and broad potential to treat psoriasis in multiple ways. Its use also plays a crucial role in improving the psoriasis phenotype and reducing the inflammatory microenvironment. In conclusion, our findings suggest that CUR alone or in combination with other conventional treatments can effectively treat psoriasis.

Transcriptome profiling in psoriasis: NB-UVB treatment-associated transcriptional changes and modulation of autoinflammation in perilesional skin in early-phase disease

BACKGROUND

Psoriasis is a chronic inflammatory skin condition. It is widely treated with phototherapy using narrowband ultraviolet B (NB-UVB). The therapeutic mechanisms of NB-UVB, however, remain unclear, particularly in the early phases of the disease.

OBJECTIVE

To investigate the mechanisms underlying the effects of NB-UVB on psoriasis in a model of perilesional psoriasis.

METHODS

Psoriatic patients that received NB-UVB treatment and were evaluated with the psoriasis area and severity index were included in the study. Skin biopsies obtained before and after treatment were subjected to RNA sequencing (RNA-seq) and Ingenuity Pathway Analyses for genome-wide transcriptome profiling to gain further insights into the signaling pathways underlying the improvement of psoriasis with therapeutic intervention.

RESULTS

Our findings revealed that NB-UVB treatment may exert its effects by suppressing nuclear factor kappa B, which leads to upregulation of the sirtuin signaling pathway, as well as by decreasing the function of major upstream regulators associated with proinflammatory and inflammatory cytokines, which blocks the expression of downstream toll-like receptors. Psoriasis improvement after NB-UVB treatment was associated with decreased expression of NFKBIZ, SERPINB4, ATG13, and CTSS and increased expression of SKP1 gene. Our results also highlighted the expression of proposed genes associated with the modulation of autoinflammation.

CONCLUSIONS

To the best of our knowledge, this is the first study to apply advanced molecular techniques to explore the effects of phototherapy on psoriasis in the early-phase, providing new insights into the disease pathogenesis and novel genetic information for the development of new therapeutic modalities and potential treatment targets.

Polysaccharide-Based Transdermal Drug Delivery

Materials derived from natural plants and animals have great potential for transdermal drug delivery. Polysaccharides are widely derived from marine, herbal, and microbial sources. Compared with synthetic polymers, polysaccharides have the advantages of non-toxicity and biodegradability, ease of modification, biocompatibility, targeting, and antibacterial properties. Currently, polysaccharide-based transdermal drug delivery vehicles, such as hydrogel, film, microneedle (MN), and tissue scaffolds are being developed. The addition of polysaccharides allows these vehicles to exhibit better-swelling properties, mechanical strength, tensile strength, etc. Due to the stratum corneum’s resistance, the transdermal drug delivery system cannot deliver drugs as efficiently as desired. The charge and hydration of polysaccharides allow them to react with the skin and promote drug penetration. In addition, polysaccharide-based nanotechnology enhances drug utilization efficiency. Various diseases are currently treated by polysaccharide-based transdermal drug delivery devices and exhibit promising futures. The most current knowledge on these excellent materials will be thoroughly discussed by reviewing polysaccharide-based transdermal drug delivery strategies.

The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients

BACKGROUND

The role of circadian rhythm abnormalities in patients with inflammatory bowel disease (IBD) remains relatively unknown. The aim of this study was to identify the inflammatory cytokine profile in the IBD patients and its relationship with the quality of sleep.

METHODS

Prospective, single-center observational cohort study was performed. In all enrolled adult IBD patients, the disease activity was assessed using Crohn's Disease Activity Index (CDAI) for Crohn's disease (CD) and Partial Mayo Score for ulcerative colitis (UC), respectively. To assess the quality of sleep, all patients were asked to respond to a questionnaire to define Pittsburgh Quality Sleep Index (PSQI). From all enrolled patients, 15 ml venous blood was taken to determine serum inflammatory cytokine levels and perform standard laboratory tests.

RESULTS

Fifty-two IBD patients were enrolled in the study: 32 with CD and 20 with UC. The poor sleep was noted in 69.4% of patients with clinically active and in 6.3% of patients with inactive disease. In the group of IBD patients with poor sleep, the significantly higher level of serum IL-6, IL-17, and IL-23 were observed. In IBD patients with exacerbation, the significantly higher level of serum IL-6, IL-17, and IL-23 were recorded.

CONCLUSIONS

The relationship between quality of sleep and proinflammatory cytokine profile may show us a predisposition for the development of inflammatory intestinal lesions in IBD patients with sleep disturbances. This knowledge may allow the pharmacological and behavioral therapies of circadian rhythm abnormalities to become new significant targets in IBD patients.

Coronary calcium in autoimmune diseases: A systematic literature review and meta-analysis

BACKGROUND AND AIMS

Autoimmune diseases (AID) share various clinical signs and symptoms and pathophysiological mechanisms including the increased risk of cardiovascular disease. The coronary artery calcium score (CACS) is potentially useful in improving the cardiovascular risk assessment. The aim of this study was to evaluate CACS in six AIDs analyzed as a group compared with controls through a systematic literature review (SLR) and meta-analysis.

METHODS

A literature search (Medline/OVID, Lilacs, Embase, and Cochrane/OVID) up to January 6, 2021 was made (PROSPERO CRD42020197182). Observational studies (patients with six AIDs: rheumatoid arthritis [RA], systemic lupus erythematosus [SLE], Sjögren's syndrome, systemic sclerosis, dermatopolymyositis, and antiphospholipid syndrome) compared with controls were included. CACS, reported in Agatston units, was the primary outcome in both groups. Mean differences and a random-effects model (DerSimonian and Laird) were calculated.

RESULTS

Nineteen articles were meta-analyzed (4568 subjects: 2142 AID and 2426 controls). Mean age was 48.1 and 44.2 years, respectively and 75.6% and 84.9% were women, respectively. Of cases, 52.9% had RA, 44.4% SLE and 2.7% had systemic sclerosis. The pooled analysis showed a higher CACS in patients with AIDs (7.42; 95% CI 1.79 to 13.05; chi²-p = 0.01) compared with controls. Meta-regression models showed that age in cases and controls reduced the difference in CACS between groups (p < 0.05), HDL had an inverse relationship (p = 0.04), and CRP levels had a directly proportional relationship with CACS in cases (p = 0.036).

CONCLUSIONS

The quantitative results of this meta-analysis suggest that CACS is higher in patients with AID, possibly due to chronic exposure to pro-inflammatory molecules. These results have clinical implications since the finding of highly elevated CACS in patients with AID will enable physicians and researchers to develop a risk stratification model that includes CACS as one of the screening tools for detecting coronary atherosclerosis in these patients.

Association of Behçet disease with psoriasis and psoriatic arthritis

Behçet disease (BD) is a debilitating multi-systemic vasculitis with a litany of muco-cutaneous manifestations and potentially lethal complications. Meanwhile, psoriasis (PSO) is a cutaneous and systemic inflammatory disorder marked by hyperplastic epidermis and silvery scales, which may be accompanied by a distinct form of arthropathy called psoriatic arthritis (PsA). While the clinical pictures of these two are quite different, they feature some important similarities, most of which may stem from the autoinflammatory components of BD and PSO. Therefore, the aim of this study was to investigate the prospective link between BD and cutaneous and articular manifestations of psoriasis. BD, PSO, and PsA cohorts were extracted using the National Health Insurance Service of Korea database. Using χ² tests, prevalence of PSO and PsA with respect to BD status was analysed. Relative to non-BD individuals, those with personal history of BD were nearly three times more likely to be diagnosed with PSO. The adjusted odds ratio (aOR) was 2.36 [95% confidence interval (CI), 1.91–2.93, p < 0.001]. Elevated PSO risk was more pronounced in the male BD cohort (aOR = 1.19, 95% CI 1.16–1.23, p < 0.001). In age-group sub-analysis, individuals over 65 years with PSO were one and a half times more likely to be affected with BD, relative to those under 65. The adjusted OR for the older group was 1.51 (95% CI 1.43–1.59, p < 0.001). BD individuals with “healthy” body weight were significantly less likely to be affected by PSO (aOR = 0.59, 95% CI 0.57–0.62, p < 0.001). On the other hand, there was a correlation between BMI and the risk of BD, with the “moderately obese (30–35 kg/m²)” group having an aOR of 1.24 (95% CI 1.12–1.38, p < 0.001). BD patients were also twice more likely to be associated with PsA (aOR = 2.19, 95% CI 1.42–3.38, p < 0.001). However, in contrast to the case of psoriatic disease itself, females were exposed to a greater risk of developing BD compared to the male PsA cohort (aOR = 2.02, 95% CI 1.88–2.16, p < 0.001). As with PSO, older BD patients were exposed to a significantly higher risk of developing PsA (aOR = 3.13, 95% CI 2.90–3.40, p < 0.001). Behçet disease may place an individual at a significantly increased risk of psoriasis, and still greater hazard of being affected with psoriatic arthritis. This added risk was pronounced in the male cohort, and tended to impact senile population, and this phenomenon may be related with the relatively poor prognosis of BD in males and PSO in older patients.

Diterpenoids and Triterpenoids From Frankincense Are Excellent Anti-psoriatic Agents: An in silico Approach

Psoriasis is a chronic autoimmune disease that affects 2–3% of the global population and requires an effective treatment. Frankincense has been long known for its potent anti-inflammatory activities. In this study, a structural bioinformatics approach was used to evaluate the efficacy of individual active components of frankincense, macrocyclic diterpenoid derivatives (1-27), and boswellic acids (28-46) in the treatment of psoriasis. Initially, major druggable targets of psoriasis were identified. Subsequently, structure-based screening was employed by using three different docking algorithms and scoring functions (MOE, AutoDock Vina, and MVD) for the target fishing of compounds against 18 possible targets of psoriasis. Janus Kinase 1, 2, 3 (JAK 1/2/3), eNOS, iNOS, interleukin-17 (IL-17), and Tumor necrosis factor-α (TNF-α) were identified as the preferred molecular targets for these compounds. This computational analysis reflects that frankincense diterpenoids and triterpenoids can serve as excellent anti-psoriatic agents by targeting major cytokines (TNF-α, IL-17, IL-13, IL-23, and IL-36γ,) exacerbated in psoriasis, and inflammatory pathways particularly JAK1/2/3, eNOS, iNOS, MAPK2, and IFNγ. The results were compared with the reported experimental findings which correlates well with our in-silico verdicts.

Circadian rhythm abnormalities in patients with inflammatory bowel disease - association with adipokine profile

Background: The role of sleep disturbances in patients with inflammatory bowel disease (IBD) remained relatively unknown. The aim of this study was to identify the adipokine profile in the patients with IBD and its relationship with the circadian rhythm disorders.Methods: Prospective, observational cohort study was performed. In all the enrolled adult IBD patients, the disease activity was assessed by using Crohn's Disease Activity Index (CDAI) for Crohn's disease (CD) and Partial Mayo Score for ulcerative colitis (UC), respectively. All patients were also asked to respond to a questionnaire to define Pittsburgh Quality Sleep Index (PSQI). From all the enrolled patients, 15 mL venous blood was taken to determine adipokine levels and perform standard laboratory tests.Results: Sixty-five IBD patients were enrolled in our study: 30 with CD and 35 with UC. Poor sleep was noted in 69.2% patients with clinically active and in 7.7% patients with inactive disease (p = .0023). In the group of IBD patients with poor sleep, the significantly higher level of serum resistin (p = .0458), and lower level of serum adiponectin and leptin (p = .0215, p = .0201; respectively) were observed. In the IBD patients with exacerbation, the significantly higher level of serum resistin (p = .0396), significantly lower serum level of leptin (p = .0453) and tendency to lower serum level of adiponectin (p = .1214) were recorded.Conclusions: The relationship between circadian rhythm abnormalities and specific adipokine profile may show us a risk factor of developing inflammatory intestinal lesions in IBD patients. This knowledge may allow the treatment of sleep disturbances, body weight-control and dietary habits become new targets in IBD therapy.

Scoping review of biological treatment of deficiency of interleukin-36 receptor antagonist (DITRA) in children and adolescents

BACKGROUND

Deficiency of interleukin-36 receptor antagonist (DITRA) is a life threatening monogenic autoinflammatory disease caused by loss of function mutations in the IL36RN gene. Affected patients develop recurrent episodes of generalized pustular psoriasis (GPP) with systemic inflammation and fever. We here review and analyze the literature on pediatric DITRA patients who have been treated by biologicals targeting inflammatory cytokines.

METHOD

A database research was performed to identify all relevant articles on pediatric DITRA patients treated with biologicals. According to defined response criteria therapeutic efficacy was analyzed.

RESULTS

Our literature research revealed 12 pediatric patients with DITRA who have received treatment with biologicals and we add a further not yet reported patient. Out of these 13 patients 10 were homozygous including 6 with the p.Leu27Pro, 3 with the p.Arg10 Argfs* and 1 with the p.Thr123Met mutation. 3 patients were compound heterozygous. In total 28 flares were treated with biological agents- targeting IL-1, IL-17, IL-12/23 and TNF-α. Complete response was achieved in 16 flares (57%), a partial reponse was seen in 2 flares (7%), and no response was observed in 10 flares (36%). Response rates were heterogeneous among the different agents. While complete/partial/no response with inhibition of TNF-alpha could be achieved in 7 (58%)/1 (8%)/4 (33%), the inhibition of IL-17 and of IL-12/23 led in each 4 flares to a 100% complete response. IL-1 inhibition led to complete/partial response in each 1 (13%) and was not effective in 6 (76%) flares. Of note, the novel patient was successfully treated with weekly dosed adalimumab.

CONCLUSIONS

DITRA is a rare disease that has to be considered in GPP with systemic inflammation and fever. It can be effectively treated with specific biological inhibition of TNF-alpha, IL-12/23 and IL- 17, while anti-IL-1 treatment seems less effective. Weekly dosed adalimumab appears to be a treatment option for pediatric patients. Further reports and studies of biological treated pediatric DITRA patients are warranted for evaluation of optimal treatment.

Chitosan-based nanoformulated (-)-epigallocatechin-3-gallate (EGCG) modulates human keratinocyte-induced responses and alleviates imiquimod-induced murine psoriasiform dermatitis

Background

Psoriasis is a chronic and currently incurable inflammatory skin disease characterized by hyperproliferation, aberrant differentiation, and inflammation, leading to disrupted skin barrier function. The use of natural agents that can abrogate these effects could be useful for the treatment of psoriasis. Earlier studies have shown that treatment of keratinocytes and mouse skin with the green tea polyphenol (−)-epigallocatechin-3-gallate (EGCG) mitigated inflammation and increased the expression of caspase-14 while promoting epidermal differentiation and cornification. However, bioavailability issues have restricted the development of EGCG for the treatment of psoriasis.

Materials and methods

To overcome these limitations, we employed a chitosan-based polymeric nanoparticle formulation of EGCG (CHI-EGCG-NPs, hereafter termed nanoEGCG) suitable for topical delivery for treating psoriasis. We investigated and compared the efficacy of nanoEGCG versus native or free EGCG in vitro and in an in vivo imiquimod (IMQ)-induced murine psoriasis-like dermatitis model. The in vivo relevance and efficacy of nanoEGCG formulation (48 µg/mouse) were assessed in an IMQ-induced mouse psoriasis-like skin lesion model compared to free EGCG (1 mg/mouse).

Results

Like free EGCG, nanoEGCG treatment induced differentiation, and decreased proliferation and inflammatory responses in cultured keratinocytes, but with a 4-fold dose advantage. Topically applied nanoEGCG elicited a significant (p<0.01) amelioration of psoriasiform pathological markers in IMQ-induced mouse skin lesions, including reductions in ear and skin thickness, erythema and scales, proliferation (Ki-67), infiltratory immune cells (mast cells, neutrophils, macrophages, and CD4⁺ T cells), and angiogenesis (CD31). We also observed increases in the protein expression of caspase-14, early (keratin-10) and late (filaggrin and loricrin) markers of differentiation, and the activator protein-1 factor (JunB). Importantly, a significant modulation of several psoriasis-related inflammatory cytokines and chemokines was observed compared to the high dose of free EGCG (p<0.05). Taken together, topically applied nanoEGCG displayed a >20-fold dose advantage over free EGCG.

Conclusion

Based on these observations, our nanoEGCG formulation represents a promising drug-delivery strategy for treating psoriasis and possibly other inflammatory skin diseases.

Inflammasomes and dermatology

Inflammasomes are intracellular multiprotein complexes that comprise part of the innate immune response. Since their definition, inflammasome disorders have been linked to an increasing number of diseases. Autoinflammatory diseases refer to disorders in which local factors lead to the activation of innate immune cells, causing tissue damage when in the absence of autoantigens and autoantibodies. Skin symptoms include the main features of monogenic inflammasomopathies, such as Cryopyrin-Associated Periodic Syndromes (CAPS), Familial Mediterranean Fever (FMF), Schnitzler Syndrome, Hyper-IgD Syndrome (HIDS), PAPA Syndrome, and Deficiency of IL-1 Receptor Antagonist (DIRA). Concepts from other pathologies have also been reviewed in recent years, such as psoriasis, after the recognition of a combined contribution of innate and adaptive immunity in its pathogenesis. Inflammasomes are also involved in the response to various infections, malignancies, such as melanoma, autoimmune diseases, including vitiligo and lupus erythematosus, atopic and contact dermatitis, acne, hidradenitis suppurativa, among others. Inhibition of the inflammasome pathway may be a target for future therapies, as already occurs in the handling of CAPS, through the introduction of IL-1 inhibitors. This study presents a literature review focusing on the participation of inflammasomes in skin diseases.

A Human Lin- CD123+ CD127low Population Endowed with ILC Features and Migratory Capabilities Contributes to Immunopathological Hallmarks of Psoriasis

Innate lymphoid cells (ILC) are members of a heterogeneous family with a lymphoid origin that mimics the T helper (Th) cytokine profile. ILC are involved in early effector cytokine-mediated responses during infections in peripheral tissues. ILC also play an important role in chronic skin inflammatory diseases, including psoriasis. Although classical ILC express CD127, it has been recently reported that the presence of non-classical CD127^- ILC populations and an early ILC precursor (EILP) CD127^low. ILC development has predominately been investigated in mouse models. However, in humans, different transcription factors have been described for ILC identification. NFIL3 (nuclear factor, IL-3 regulated) is crucial for ILC development in response to IL-7. CD123 (IL-3Rα) is usually used to exclude basophils during ILC identification, however, it is unknown if in response to IL-3, NFIL3 could be relevant to induce ILC features in Lin^- CD123⁺ populations in addition, is also unknown whether peripheral blood (PB) population with ILC features may have skin-homing potential to participate in skin inflammatory chronic diseases. Here, we report a Lin^- CD123⁺ CD127^low CD7⁺ CLA⁺ population that share some phenotypic properties with basophils, but expresses several transcription factors for ILC commitment such as inhibitor of DNA binding 2 (Id2), NFIL3, promyelocytic leukemia zinc finger (PLZF), thymocyte selection-associated high-mobility group box protein (TOX), and T cell factor-1 (TCF-1). In addition, this population expresses different ILC markers: CD132, CD90, CD161, α4 integrin, c-Kit, CRTH2, AhR, and IL-23R. IL-3 prevents apoptosis and increases their NFIL3, TOX, and PLZF expression. In PB, the CD123⁺ CD127^low population is predominantly a conspicuous population that expresses T-bet and RORγt. The Lin^- CD123⁺ CD127^low population in PB has a limited Th type cytokine expression and highly expresses IL-8. The Lin^- CD123⁺ CD127^low population expresses skin-homing receptors (cutaneous lymphocyte antigen and CXCR4) and transmigrates through endothelial cells in response to SDF-1. An equivalent Lin^- CD123^low population was identified in control skin, which shows a broader phenotypic diversity and cytokine production, including IL-22 and IL-17. Remarkably, the CD123^low population in the lesion and non-lesion skin of psoriasis patients expresses IL-17 and IL-22. Our findings suggest the identification of an alternative Lin^- CD123⁺ CD127^low population with ILC features endowed with migratory capabilities that might contribute to immunopathological hallmarks of psoriasis.

Myeloid-Derived Suppressor Cells in Psoriasis Are an Expanded Population Exhibiting Diverse T-Cell-Suppressor Mechanisms

Psoriasis vulgaris is an inflammatory skin disease caused by hyperactivated T cells regulated by positive and negative mechanisms; although the former have been much studied, the latter have not. We studied the regulatory mechanism mediated by myeloid-derived suppressor cells (MDSCs) and showed that MDSCs expanded in melanoma patients express dendritic cell-associated heparan sulfate proteoglycan-dependent integrin ligand, a critical mediator of T-cell suppressor function. We examined expansion of DC-HIL(+) MDSCs in psoriasis and characterized their functional properties. Frequency of DC-HIL(+) monocytic MDSCs (CD14(+)HLA-DR(no/low)) in blood and skin was markedly increased in psoriatic patients versus healthy control subjects, but there was no statistically significant relationship with disease severity (based on Psoriasis Area and Severity Index score). Blood DC-HIL(+) MDSC levels in untreated patients were significantly higher than in treated patients. Compared with melanoma-derived MDSCs, psoriatic MDSCs exhibited significantly reduced suppressor function and were less dependent on DC-HIL, but they were capable of inhibiting proliferation and IFN-γ and IL-17 responses of autologous T cells. Psoriatic MDSCs were functionally diverse among patients in their ability to suppress allogeneic T cells and in the use of either IL-17/arginase I or IFN-γ/inducible nitric oxide synthase axis as suppressor mechanisms. Thus, DC-HIL(+) MDSCs are expanded in psoriasis patients, and their mechanistic heterogeneity and relative functional deficiency may contribute to the development of psoriasis.

Circadian rhythm abnormalities - Association with the course of inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are the main representatives of inflammatory bowel diseases (IBD), a group of chronic, immune system-mediated inflammatory diseases of the gastrointestinal (GI) tract. The pathogenesis of the intestinal lesions in IBD is not entirely identified and understood: excessive activation of the immune system may come as a result of the interaction of various environmental and infectious factors, genetic predisposition, and the mediation of abnormal intestinal flora. The main objective of the current study is to further identify the risk factors for the development of IBD. Currently, there is very little knowledge about circadian rhythm and IBD and there are only a few studies on the relationship between sleep disturbances and the course of the disease, as well as pro- and anti-inflammatory cytokine profile and general immune system functioning. Furthermore, the relationship between the expression of circadian rhythm genes and severe course of IBD is still unknown. The aim of this review is to show the current state of knowledge about the relationship between circadian rhythm disorders, sleep disturbance and inflammation in the GI tract and to analyze the possibility of employing this knowledge in diagnosis and treatment of IBD.

Keratinocytes express functional CARD18, a negative regulator of inflammasome activation, and its altered expression in psoriasis may contribute to disease pathogenesis

Caspase recruitment domain family member 18 (CARD18, Iceberg) is known as a negative regulatory molecule that inhibits inflammatory events by terminating inflammasome activation due to a direct interaction with pro-caspase-1. During the investigation of molecular mechanisms in keratinocytes that contribute to the pathogenesis of psoriasis, we found that CARD18 expression differs in healthy and psoriatic skin; moreover, CARD18 demonstrated altered response under inflammatory conditions in healthy and psoriatic skin. In healthy skin, low basal CARD18 expression was detected, which showed significant elevation in response to inflammatory stimuli (lymphokine treatment or mechanical injury). In contrast, higher basal expression was observed in psoriatic non-involved skin, but no further induction could be detected. We demonstrated that keratinocytes express CARD18 both at mRNA and protein levels and the expression increased in parallel with differentiation. The investigation of cellular inflammatory processes revealed that psoriasis-associated danger signals triggered the expression of inflammasome components (AIM2, Caspase-1) and CARD18 as well as IL-1β production of keratinocytes. Furthermore, gene-specific silencing of CARD18 in cells treated with cytosolic DNA (poly(dA:dT)) resulted in increased IL-1β secretion, suggesting a negative regulatory role for CARD18 in keratinocyte inflammatory signaling. The differential regulation of CARD18 in healthy and psoriatic uninvolved epidermis may contribute to the susceptibility of psoriasis. Furthermore, our in vitro results indicate that CARD18 may contribute to the fine tuning of keratinocyte innate immune processes.

Cytotoxic T lymphocytes as a potential brake of keratinocyte proliferation in psoriasis

Psoriasis is a chronic papulosquamous skin disease, histologically characterized by epidermal hyperproliferation and dermal infiltration of inflammatory cells. The majority of T lymphocytes infiltrating dermis are CD4+ T lymphocytes secreting type 1 and type 17 cytokines. These cytokines are responsible for triggering keratinocyte proliferation as well as chemokine secretion and subsequent migration of other inflammatory cells in the skin. Contrarily, lymphocytes that accumulate in epidermis are mainly CD8+ T lymphocytes. According to the recent findings, these cells can also secrete type 1 and type 17 cytokines. However, it is demonstrated so far that epidermal CD8+ T lymphocytes contain higher amounts of cytolytic molecules, such as perforin, granzyme B and granulysin whose role in psoriasis pathogenesis is still unknown. Therefore, in this article we hypothesize the active involvement of cell mediated cytotoxicity in killing the proliferating keratinocytes as a mechanism of potential self-defense and possible brake in psoriatic plaque formation, maintaining skin homeostasis.

Toll-like receptor 9 promoter polymorphism as a predictive factor of narrow-band UVB phototherapy response in patients with psoriasis

BACKGROUND

Prediction of response to ultraviolet B (UVB) phototherapy in psoriatic patients mainly relies on clinical criteria, although some genetic predictors have been identified. Toll-like receptors (TLRs) have been involved in psoriasis pathogenesis through activation of the innate immune system. Their polymorphisms may condition not only the clinical profile of psoriasis but also the response to therapy.

METHODS

We analyzed the role of functional single-nucleotide polymorphisms (SNPs) of TLR2, 5, 4, and 9 in clinical response to a standard narrow-band UVB (NBUVB) therapy in 39 patients with moderate to severe psoriasis.

RESULTS

We found a significant relationship between TLR9-1486T/C SNP variants and a better response to NBUVB phototherapy. Patients with TC and CC genotype showed a higher improvement of Psoriasis Area and Severity Index (PASI) than patients with TT genotype. Results of multivariate analysis indicate that the differences in PASI improvement at the end of phototherapy attributed to TRL9 SNP genotype were not dependent on the patients' phototype, age, gender, body mass index, basal PASI, or disease evolution.

CONCLUSIONS

We describe a functional genetic variant in TLR9 gene that might affect the susceptibility to antipsoriatic treatment. The search of genetic predictive factors may be helpful in therapy selection and optimization of therapeutic regimes in psoriatic patients.

Topical application of delphinidin reduces psoriasiform lesions in the flaky skin mouse model by inducing epidermal differentiation and inhibiting inflammation

BACKGROUND

Psoriasis is a chronic inflammatory skin disease characterized by hyperproliferation and aberrant keratinocyte differentiation. We have shown that treatment of reconstituted human skin with delphinidin, an anthocyanidin, present in pigmented fruits and vegetables, increased the expression and processing of caspase-14, which is involved in cornification. Delphinidin also increases the expression of epidermal differentiation marker proteins.

OBJECTIVES

To determine whether topical application of delphinidin can modulate pathological markers of psoriasiform lesions in flaky skin mice and if this is associated with increased epidermal differentiation and a reduction in proliferation and inflammation.

METHODS

Five-week-old female homozygous flaky skin mice (fsn/fsn) were treated topically with delphinidin (0·5 mg cm(-2) and 1 mg cm(-2) skin areas, respectively), five times a week, up to 14 weeks of age.

RESULTS

Treatment of flaky skin mice with delphinidin resulted in a reduction in (i) pathological markers of psoriasiform lesions; (ii) infiltration of inflammatory cells; and (iii) mRNA and protein expression of inflammatory cytokines. Delphinidin treatment also increased the expression and processing of caspase-14, and expression of filaggrin, loricrin, keratin-1 and keratin-10. Furthermore, there was a decrease in the expression of markers for cell proliferation (proliferating cell nuclear antigen and keratin-14) and modulation of tight junction proteins (occludin and claudin-1). In addition, delphinidin treatment increased the expression of activator protein-1 transcription factor proteins (JunB, JunD, Fra1 and Fra2).

CONCLUSIONS

Delphinidin could be a promising agent for treatment of psoriasis and other hyperproliferative skin disorders.

Chronic inflammatory diseases: do immunological patterns drive the choice of biotechnology drugs? A critical review

Chronic inflammatory diseases represent a heterogeneous group of conditions that can affect practically any organ or system. An increasing number of biologic agents have been developed to selectively target the cell populations and signaling pathways involved in chronic inflammation, including cytokines, monoclonal antibodies and engineered receptors. This approach has been remarkably successful in alleviating some of the signs and symptoms of refractory autoimmune diseases. The use of this therapeutic strategy is likely to increase with the introduction of biosimilar agents. The different nature of these biological products makes the comparison of their pharmaceutical and clinical characteristics difficult, including safety and potency and these issues may be particularly relevant in the case of biosimilars. In addition, the heterogeneity of autoimmune diseases and of autoimmune patients, further adds to the complexity of choosing the right drug for each patient and predicting efficacy and safety of the treatment. In this review, we summarize actual knowledge about current biological agents and their use in autoimmune diseases, with a special emphasis for rheumatoid arthritis, inflammatory bowel diseases and psoriasis. The purpose of this analysis is to address the most critical issues raised by the rapid advancements in this field over recent years, and to acknowledge the potentially valuable gains brought about by the increasing availability of these new biologic agents.

Integrative clinical transcriptomics analyses for new therapeutic intervention strategies: a psoriasis case study

Psoriasis is a chronic inflammatory skin disease with complex pathological features and unmet pharmacotherapy needs. Here, we present a framework for developing new therapeutic intervention strategies for psoriasis by utilizing publicly available clinical transcriptomics data sets. By exploring the underlying molecular mechanisms of psoriasis, the effects of subsequent perturbation of these mechanisms by drugs and an integrative analysis, we propose a psoriasis disease signature, identify potential drug repurposing opportunities and present novel target selection methodologies. We anticipate that the outlined methodology or similar approaches will further support biomarker discovery and the development of new drugs for psoriasis.