Oxidative stress involvement in psoriasis: a systematic review

HMGB-1 in Psoriasis

Psoriasis is a multifactorial pathology linked to systemic inflammation. Enhanced keratinocytes proliferation and a minor maturation state of the cells are typical features. Perivascular T cells, dendritic cells, macrophages, and neutrophilic granulocytes are part of the scenario completed by apoptosis dysregulation. Several proinflammatory mediators, alarmins and growth factors are increased too, both in the skin and the patients’ blood. HMGB1 is important as an alarmin in several inflammatory conditions. Released after cellular damage, HMGB1 acts as a danger signal. Several studies have considered its role in psoriasis pathogenesis. We evaluated its level in psoriasis and the potential of the alarmin blockade through standard therapies, biological treatments and using monoclonal antibodies. PV patients were shown to have significantly increased levels of HMGB1 both in lesional skin and in serum, which were linked, in some cases, to other pro-inflammatory markers and alarmins. In most cases these parameters were correlated with PASI score. Data demonstrated that blocking HMGB1 is effective in ameliorating psoriasis. Focusing on this approach could be valuable in terms of a therapeutic option for counteracting immune-related diseases in a way unthinkable until few years ago.

Astragalus mongholicus Bunge Water Extract Exhibits Anti-inflammatory Effects in Human Neutrophils and Alleviates Imiquimod-Induced Psoriasis-Like Skin Inflammation in Mice

Neutrophils are the primary immune cells in innate immunity, which are related to various inflammatory diseases. Astragalus mongholicus Bunge is a Chinese medicinal herb used to treat various oxidative stress-related inflammatory diseases. However, there are limited studies that elucidate the effects of Astragalus mongholicus Bunge in human neutrophils. In this study, we used isolated human neutrophils activated by various stimulants to investigate the anti-inflammatory effects of Astragalus mongholicus Bunge water extract (AWE). Cell-free assays were used to examine free radicals scavenging capabilities on superoxide anion, reactive oxygen species (ROS), and nitrogen-centered radicals. Imiquimod (IMQ) induced psoriasis-like skin inflammation mouse model was used for investigating anti-psoriatic effects. We found that AWE inhibited superoxide anion production, ROS generation, and elastase release in human neutrophils, which exhibiting a direct anti-neutrophil effect. Moreover, AWE exerted a ROS scavenging ability in the 2,2’-Azobis (2-amidinopropane) dihydrochloride assay, but not superoxide anion in the xanthine/xanthine oxidase assay, suggesting that AWE exhibited anti-oxidation and anti-inflammatory capabilities by both scavenging ROS and by directly inhibiting neutrophil activation. AWE also reduced CD11b expression and adhesion to endothelial cells in activated human neutrophils. Meanwhile, in mice with psoriasis-like skin inflammation, administration of topical AWE reduced both the affected area and the severity index score. It inhibited neutrophil infiltration, myeloperoxidase release, ROS-induced damage, and skin proliferation. In summary, AWE exhibited direct anti-inflammatory effects by inhibiting neutrophil activation and anti-psoriatic effects in mice with IMQ-induced psoriasis-like skin inflammation. Therefore, AWE could potentially be a pharmaceutical Chinese herbal medicine to inhibit neutrophilic inflammation for anti-psoriasis.

Perillyl alcohol inhibits keratinocyte proliferation and attenuates imiquimod-induced psoriasis like skin-inflammation by modulating NF-κB and STAT3 signaling pathways

Psoriasis is a chronic inflammatory and proliferative skin disease characterized by pathological skin lesions which significantly impact the quality of life. Recent studies have been proven that inhibitors of farnesyltransferase enzyme showed significant anti-psoriatic activity. Perillyl alcohol (POH) is one such natural molecule having anti proliferative, anti-inflammatory and anti-oxidant properties by inhibiting farnesyltransferase enzyme which further down regulates NF-κB and STAT3 via Ras/Raf/MAPK pathway. Hence, in the current study we aimed to find the effect of POH on human keratinocytes (HaCat) cells in in-vitro and IMQ induced psoriatic like skin inflammation model in mice. POH significantly decreased the intracellular ROS levels and inhibited the phosphorylation of NF-κB and STAT3 in in-vitro. It was found that POH (200 mg/kg, topical application) has reduced the epidermal hyperplasia, psoriasis area and severity index (PASI) scoring; splenomegaly in imiquimod (IMQ) induced psoriatic mice. Further, POH treatment has decreased the pro-inflammatory serum cytokine levels such as IL-6, IL-12/23, TNF-α and IL-1β and also reduced the expression levels of various inflammatory proteins, COX-2, iNOS, IL-17A, IL-22, NF-кB and STAT3 evidenced by Immunoblotting studies from skin samples. The levels of endogenous antioxidants like glutathione GSH, SOD, Nrf2 were restored to normal levels upon POH treatment. POH downregulated the proteins levels of TLR7, TLR8, CyclinD1 and mRNA expression of Bcl-2 in the skin samples when compared to the IMQ group. POH has ameliorated the hyper-keratosis and acanthosis which was evidenced by histopathology. Collectively, our results suggest that POH has a promising therapeutic application for ameliorating psoriasis-like skin inflammation.

Role of Epithelium-Derived Cytokines in Atopic Dermatitis and Psoriasis: Evidence and Therapeutic Perspectives

Atopic dermatitis and psoriasis are two of the most common chronic skin conditions. Current target therapies represent viable and safe solutions for the most severe cases of these two dermatoses but, presently, several limitations exist in terms of efficacy and side effects. A new class of products, epithelium-derived cytokines (TSLP, IL-25, IL-33), show an increasing potential for use in target therapy for these patients, and demonstrate a direct link between a generalized inflammatory and oxidative stress status and the human skin. A review was conducted to better understand their role in the aforementioned conditions. Of these three molecules, TSLP led has been most often considered in studies regarding target therapies, and most of the results in the literature are related to this cytokine. These three cytokines share common stimuli and are linked to each other in both acute and chronic phases of these diseases, and have been challenged as target therapies or biomarkers of disease activity. The results lead to the conclusion that epithelium-derived cytokines could represent a therapeutic opportunity for these patients, especially in itch control. Furthermore, they might work better when paired together with currently available therapies or in combination with in-development treatments. Further studies are needed in order to verify the efficacy and safety of the biologic treatments currently under development.

MiR-1294 suppresses ROS-dependent inflammatory response in atopic dermatitis via restraining STAT3/NF-κB pathway

Atopic dermatitis (AD) is a common inflammatory skin disorder that affects children and adults. Despite the pathology of AD involves in immune dysfunction and epidermal barrier function destruction has been found, the mechanism of immune activation and barrier damage remain largely unknown. In the present study, The TNF-α/IFN-γ-stimulated HaCaTs, organotypic AD-like 3D skin equivalents and AD-like mouse model were constructed. The mRNA, histological morphology, protein levels, cytokines were detected by real-time quantitative polymerasechain reaction (RT-qPCR), hematoxylin and eosin (H & E) staining, Immunohistochemistry (IHC), immunoblotting, immunofluorescence (IF) staining, and enzyme linked immunosorbent assay (ELISA), respectively. Cell viability, cell cycle, and apoptosis were respectively calculated using a Methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay and flow cytometry. A dual-luciferase reporter gene system was used to investigate the relationship between miR-1294 and STAT3. Compared with the control group, the expression of miR-1294 decreased in TNF-α/IFN-γ-stimulated HaCaTs (P < 0.001), AD-like skin model, and AD-like mouse model (P < 0.001). Moreover, STAT3 was documented as a direct target of miR-1294. Inflammation (P < 0.05) and epidermal barrier function destruction (P < 0.05) in AD was suppressed by overexpression of miR-1294 but enhanced by STAT3 upregulation and its downstream NF-κB pathway. We also found miR-1294 upregulation inhibited inflammation and epidermal barrier function destruction via targeting STAT3 to suppress NF-κB pathway activation in AD.

The skin redoxome

Redoxome is the network of redox reactions and redox active species (ReAS) that affect the homeostasis of cells and tissues. Due to the intense and constant interaction with external agents, the human skin has a robust redox signalling framework with specific pathways and magnitudes. The establishment of the skin redoxome concept is key to expanding knowledge of skin disorders and establishing better strategies for their prevention and treatment. This review starts with its definition and progress to propose how the master redox regulators are maintained and activated in the different conditions experienced by the skin and how the lack of redox regulation is involved in the accumulation of several oxidation end products that are correlated with various skin disorders.

Topical Delivery of Rapamycin by Means of Microenvironment-Sensitive Core-Multi-Shell Nanocarriers: Assessment of Anti-Inflammatory Activity in an ex vivo Skin/T Cell Co-Culture Model

Introduction

Rapamycin (Rapa) is an immunosuppressive macrolide that inhibits the mechanistic target of rapamycin (mTOR) activity. Thanks to its anti-proliferative effects towards different cell types, including keratinocytes and T cells, Rapa shows promise in the treatment of skin diseases characterized by cell hyperproliferation. However, Rapa skin penetration is limited due to its lipophilic nature (log P = 4.3) and high molecular weight (MW = 914 g/mol). In previous studies, new microenvironment-sensitive core multishell (CMS) nanocarriers capable of sensing the redox state of inflamed skin were developed as more efficient and selective vehicles for macrolide delivery to inflamed skin.

Methods

In this study, we tested such redox-sensitive CMS nanocarriers using an inflammatory skin model based on human skin explants co-cultured with Jurkat T cells. Serine protease (SP) was applied on skin surface to induce skin barrier impairment and oxidative stress, whereas phytohaemagglutinin (PHA), IL-17A, and IL-22 were used to activate Jurkat cells. Activation markers, such as CD45 and CD69, phosphorylated ribosomal protein S6 (pRP-S6), and IL-2 release were monitored in activated T cells, whereas pro-inflammatory cytokines were measured in skin extracts and culture medium.

Results

We found that alteration of skin barrier proteins corneodesmosin (CDSN), occludin (Occl), and zonula occludens-1 (ZO-1) as well as oxidation-induced decrease of free thiol groups occurred upon SP-treatment. All Rapa formulations exerted inhibitory effects on T cells after penetration across ex vivo skin. No effects on skin inflammatory markers were detected. The superiority of the oxidative-sensitive CMS nanocarriers over the other formulations was observed with regard to drug delivery as well as downregulation of IL-2 release.

Conclusion

Overall, our results demonstrate that nanocarriers addressing features of diseased skin are promising approaches to improve the topical delivery of macrolide drugs.

Analytical approaches to assess metabolic changes in psoriasis

Psoriasis is one of the most common human skin diseases, although its development is not limited to one tissue, but is associated with autoimmune reactions throughout the body. Overproduction of pro-inflammatory cytokines and growth factors systemically stimulates the proliferation of skin cells, which manifests as excessive exfoliation of the epidermis, and/or arthritis, as well as other comorbidities such as insulin resistance, metabolic syndrome, hypertension, and depression. Thus, there is a great need for a thorough analysis of the pathophysiology of psoriatic patients, including classical methods, such as spectrophotometry, chromatography, or Western blot, and also novel omics approaches such as lipidomics and proteomics. Moreover, the extensive pathophysiology forces increased research examining biological changes in both skin cells, and systemically. A wide range of techniques involved in lipidomic research based on a combination of mass spectrometry and different types of chromatography (RP-LC-QTOF-MS/MS, HILIC-QTOF-MS/MS or RP-LC-QTRAP-MS/MS), have allowed comprehensive assessment of lipid modification in psoriatic skin and provided new insight into the role of lipids and their mechanism of action in psoriasis. Moreover, proteomic analysis using gel-nanoLC-OrbiTrap-MS/MS, as well as MALDI-TOF/TOF techniques facilitates the description of panels of enzymes involved in lipidome modifications, and the response of the endocannabinoid system to metabolic changes. Psoriasis is known to alter the expression of proteins that are involved in the inflammatory and antioxidant response, as well as protein biosynthesis, degradation, as well as cell proliferation and apoptosis. Knowledge of changes in the lipidomic and proteomic profile will not only allow the understanding of psoriasis pathophysiology, but also facilitate proper and early diagnosis and effective pharmacotherapy.

Cytosolic DNA‒Mediated STING-Dependent Inflammation Contributes to the Progression of Psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by an active dynamic interplay between immune cells and keratinocytes (KCs). STING is a universal receptor that recognizes cytosolic DNA and triggers innate immune activation. This study aims to elucidate the role of STING in the inflammation in psoriasis. STING deficiency alleviated psoriatic symptoms and inflammation in mouse models of psoriasis. Stimulation of macrophages with double-stranded DNA induced STING-dependent release of TNF-α and hydrogen peroxide in vitro. Furthermore, incubation of KCs with TNF-α or hydrogen peroxide increased oxidative DNA damage, induced nuclear DNA release into the cytosol, and inhibited double-stranded DNA‒induced degradation of STING protein. More importantly, transfection of KCs with double-stranded DNA synergized with TNF-α or hydrogen peroxide to induce STING-dependent activation of NF-κB and subsequent expression of Il1b, Ccl20, and Cxcl10. Finally, exposure to 5,6-dimethylxanthenone-4-acetic acid (a STING agonist) aggravated psoriatic symptoms and inflammation in wild-type mice but not in STING-deficient mice. Collectively, STING functioned as a self-DNA sensor in macrophages and KCs of psoriatic skin. Cytosolic DNA-induced activation of STING in immune cells and KCs acted synergistically and contributed to the inflammation in psoriasis.

Involvement of microRNAs as a Response to Phototherapy and Photodynamic Therapy: A Literature Review

The current knowledge about the mechanisms of action of light-based treatments (chiefly photodynamic therapy and phototherapy) in skin diseases leans to the possible involvement of epigenetic and oxidative stress mechanisms. To better understand and exploit, to the fullest, these relatively safe and reproducible treatments, several studies have focused on miRNAs, small non-encoding RNAs (22–24 nucleotides), after light-based treatments. The current narrative review focused on 25 articles. A meta-analysis was not deemed appropriate. The results gather the most recurrent skin-related miRNAs up- or downregulated after light treatment. Five of these, miR-21, -29, -125, -145 and -155, are either the most consistently related to efficacy/resistance to treatment or identified as helpful diagnostic tools. A specific class of miRNAs (angioMIRs) requires further studies. Future treatments and imaging techniques could benefit greatly from the use of antagomirs as a possible co-adjuvant therapy along with light-based treatments.

Current evidence to support the therapeutic potential of flavonoids in oxidative stress-related dermatoses

BACKGROUND

Skin, as a crucial external defense organ, is more vulnerable to oxidative stress (OS) insult, reactive oxygen species (ROS)-mediated OS in particular. OS results from a redox imbalance caused by various extrinsic stimuli and occurs once the oxidants production overwhelming the antioxidants capacity, through mediating in DNA damage, lipid peroxidation (LPO), protein oxidation and a serial of signaling pathways activation/inactivation, thereby offering favorable conditions for the occurrence and development of numerous diseases especially some dermatoses, e.g. psoriasis, vitiligo, skin photodamage, skin cancer, systemic sclerosis (SSc), chloasma, atopic dermatitis (AD), pemphigus, etc. Targeting OS molecular mechanism, a variety of anti-OS agents emerge, in which flavonoids, natural plant extracts, stand out.

OBJECTIVES

To discuss the possible mechanisms of OS mediating in dermatoses and summarize the properties of flavonoids as well as their applications in OS-related skin disorders.

METHODS

Published papers on flavonoids and OS-related skin diseases were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc.

RESULTS

It has been confirmed that flavonoids, belonging to polyphenols, are a class of plant secondary metabolites widely distributed in various plants and possess diverse bioactivities especially their potent antioxidant capacity. Moreover, flavonoids benefit to suppress OS via eliminating free radicals and mediating the corresponding signals, further excellently working in the prevention and management of OS-related skin diseases.

CONCLUSION

Flavonoids have the potential therapeutic effects on oxidative stress-related dermatoses. However, more studies on specific mechanism as well as the dosage of flavonoids are needed in future.

Oxidative stress in the skin: Impact and related protection

Skin, our first interface to the external environment, is subjected to oxidative stress caused by a variety of factors such as solar ultraviolet, infrared and visible light, environmental pollution, including ozone and particulate matters, and psychological stress. Excessive reactive species, including reactive oxygen species and reactive nitrogen species, exacerbate skin pigmentation and aging, which further lead to skin tone unevenness, pigmentary disorder, skin roughness and wrinkles. Besides these, skin microbiota are also a very important factor ensuring the proper functions of skin. While environmental factors such as UV and pollutants impact skin microbiota compositions, skin dysbiosis results in various skin conditions. In this review, we summarize the generation of oxidative stress from exogenous and endogenous sources. We further introduce current knowledge on the possible roles of oxidative stress in skin pigmentation and aging, specifically with emphasis on oxidative stress and skin pigmentation. Meanwhile, we summarize the science and rationale of using three well-known antioxidants, namely vitamin C, resveratrol and ferulic acid, in the treatment of hyperpigmentation. Finally, we discuss the strategy for preventing oxidative stress-induced skin pigmentation and aging.

Neutrophils as Drivers of Immune Dysregulation in Autoimmune Diseases with Skin Manifestations

Dysregulation in the phenotype and function of neutrophils may play important roles in the initiation and perpetuation of autoimmune responses, including conditions affecting the skin. Neutrophils can have local and systemic effects on innate and adaptive immune cells as well as on resident cells in the skin, including keratinocytes (KCs). Aberrant formation/clearance of neutrophil extracellular traps (NETs) in systemic autoimmunity and chronic inflammatory diseases have been associated with the externalization of modified autoantigens in peripheral blood and tissues. NETs can impact the function of many cells, including macrophages, lymphocytes, dendritic cells, fibroblasts, and KCs. Emerging evidence has unveiled the pathogenic key roles of neutrophils in systemic lupus erythematosus, idiopathic inflammatory myopathies, psoriasis, hidradenitis suppurativa, and other chronic inflammatory conditions. As such, neutrophil-targeting strategies represent promising therapeutic options for these diseases.

Therapies with Antioxidant Potential in Psoriasis, Vitiligo, and Lichen Planus

Oxidative stress plays an important pathogenetic role in many chronic inflammatory diseases, including those of dermatological interest. In particular, regarding psoriasis, vitiligo, and lichen planus, excess reactive oxygen species and a decline in endogenous antioxidant systems are observed. In this regard, treatments with antioxidant properties could be appropriate therapeutic options. To date, clinical trials in dermatology on these treatments are limited. We reviewed the available studies on the efficacy of antioxidant therapies in psoriasis, vitiligo, and lichen planus. The role of herbal derivatives, vitamins, and trace elements was analyzed. The antioxidant properties of conventional therapies were also evaluated. Data from the literature suggest that antioxidants might be useful, but available studies on this topic are limited, heterogeneous, not completely standardized, and on small populations. Furthermore, in most cases, antioxidants alone are unable to induce significant clinical changes, except perhaps in mild forms, and must be used in conjunction with standard drug treatments to achieve measurable results. Further studies need to be conducted, considering larger populations and using internationally validated scales, in order to compare the results and clinical efficacy.

Oxidative Stress in Cutaneous Lichen Planus-A Narrative Review

Lichen planus (LP) is a chronic, immune-mediated inflammatory skin condition that mainly affects the skin (cutaneous LP, CLP) and oral mucosa (oral LP, OLP). However, the mechanisms involved in the pathogenesis of the disease are not fully elucidated. Over time, several theories that could explain the appearance of LP lesions have been postulated. The key players in LP pathogenesis are the inflammatory infiltrate consisting of T cells and the proinflammatory cytokines. The cytokines stimulate the production of reactive oxygen species that induce cell apoptosis, a defining element encountered in LP. The lead inquiry triggered by this revolves around the role of oxidative stress in LP development. There are currently numerous studies showing the involvement of oxidative stress in OLP, but in terms of CLP, data are scarce. In this review, we analyze for the first time the currently existing studies on oxidative stress in CLP and summarize the results in order to assess the role of oxidative stress in skin lesions offering a fresher updated perspective.

Human adipose tissue-derived MSCs improve psoriasis-like skin inflammation in mice by negatively regulating ROS

BACKGROUND

Psoriasis is chronic incurable skin inflammation. The anti-inflammatory properties of mesenchymal stem cells (MSCs) have been put forward to be involved in several inflammatory diseases. However, little was known about the role of human adipose tissue-derived stem cells (hAD-MSCs) in psoriasis.

OBJECTIVE

We sought to explore the feasibility of using hAD-MSCs infusion as a therapeutic approach in psoriatic mice.

METHODS

We constructed the psoriasis-like model by IMQ implication, treated with hAD-MSCs by subcutaneous injection. To evaluate the efficacy, we examined the histology, CD45 and ROS positive cells by HE and flow cytometry respectively. We also tested the key cytokines with PCR. Moreover, to achieve a better therapeutic effect, we treated the model by combing with vitamin E application.

RESULTS

We found that the classic histological symptoms of psoriasis were relieved after treatment with hAD-MSCs, also, the splenic index, the infiltration of immune cells and several pro-inflammatory cytokines were decreased. Interestingly, we also found that hAD-MSCs could inhibit ROS generation. Moreover, the combination therapy of hAD-MSCs and vitamin E could promote the curative effect with greater ROS inhibition.

CONCLUSION

These results suggested that hAD-MSCs could be useful for treating psoriasis by negatively regulating ROS.

Anti-Angiogenic Efficacy of PSORI-CM02 and the Associated Mechanism in Psoriasis In Vitro and In Vivo

Psoriasis is a chronic proliferative autoimmune dermatologic disease characterised by abnormal angiogenesis. Thus, regulating angiogenesis in the skin is an important treatment strategy for psoriasis. PSORI-CM02, an empirical Chinese medicine formula optimised from Yin Xie Ling, was created by the Chinese medicine specialist, Guo-Wei Xuan. Clinical studies have shown that PSORI-CM02 is safe and effective for the treatment of psoriasis. However, its anti-psoriatic mechanisms remain to be further explored. In this study, we investigated the effects of PSORI-CM02 on angiogenesis in the skin and the underlying mechanisms in IL-17A-stimulated human umbilical vein endothelial cells (HUVECs) and a murine model of imiquimod (IMQ)-induced psoriasis. In vitro, PSORI-CM02 significantly inhibited the proliferation and migration of IL-17A-stimulated HUVECs in a dose-dependent manner. Further, it markedly regulated the antioxidative/oxidative status and inflammation; suppressed the expression of VEGF, VEGFR1, VEGFR2, ANG1, and HIF-1α; and reduced the phosphorylation of MAPK signalling pathway components in IL-17A-stimulated HUVECs. In vivo studies showed that PSORI-CM02 markedly reduced angiogenesis in the skin of mice with IMQ-induced psoriasis, while significantly rebalancing antioxidant/oxidant levels; inhibiting the production of IL-6, TNF-α, IL-17A, and IL-17F; and repressing the synthesis of angiogenic mediators. In addition, PSORI-CM02 markedly reduced the activation of the MAPK signalling pathway in psoriatic skin tissue. Taken together, our results demonstrated that PSORI-CM02 inhibited psoriatic angiogenesis by reducing the oxidative status and inflammation, suppressing the expression of angiogenesis-related molecules, and inhibiting the activation of the MAPK signalling pathway in vitro and in vivo.

Oxidation-Sensitive Core-Multishell Nanocarriers for the Controlled Delivery of Hydrophobic Drugs

A synthetic route for oxidation-sensitive core-multishell (osCMS) nanocarriers was established, and their drug loading and release properties were analyzed based on their structural variations. The nanocarriers showed a drug loading of 0.3-3 wt % for the anti-inflammatory drugs rapamycin and dexamethasone and the photosensitizer meso-tetra-hydroxyphenyl-porphyrin (mTHPP). Oxidative processes of the nanocarriers were probed in vitro by hydrogen peroxide, and the degradation products were identified by infrared spectroscopy supported by ab initio calculations, yielding mechanistic details on the chemical changes occurring in redox-sensitive nanocarriers. Oxidation-triggered drug release of the model drug Nile Red measured and assessed by time-dependent fluorescence spectroscopy showed a release of up to 80% within 24 h. The drug delivery capacity of the new osCMS nanocarriers was tested in ex vivo human skin with and without pretreatments to induce local oxidative stress. It was found that the delivery of mTHPP was selectively enhanced in skin under oxidative stress. The number and position of the thioether groups influenced the physicochemical as well as drug delivery properties of the carriers.

IL-33 in Mental Disorders

Mental disorders are common in the general population; every year about 25% of the total European population is affected by a mental condition. The prevalence of psychiatric disorders might be underestimated. Emerging evidence highlights the role of immune response as a key factor in MDs. Immunological biomarkers seem to be related to illness progression and to treatment effectiveness; several studies suggest strong associations among IL-6, TNFa, S100b, IL 1b, and PCR with affective or schizophrenic disorders. The purpose of this review is to examine and to understand the possible link between mental disorders and interleukin 33 to clarify the role of this axis in the immune system. We found 13 research papers that evaluated interleukin 33 or interleukin 31 levels in subjects affected by mental disorders. Eight studies investigated cytokines in affective disorders. Three studies measured levels of IL-33 in schizophrenia and two studies focused on patients affected by autism spectrum disorders. Alterations in brain structure and neurodevelopmental outcome are affected by multiple levels of organization. Disorders of the autoimmune response, and of the IL-33/31 axis, may therefore be one of the factors involved in this process. These results support the evidence that alarmins, particularly the IL-33/31 axis, need more consideration among researchers and practitioners.

Cimifugin ameliorates imiquimod-induced psoriasis by inhibiting oxidative stress and inflammation via NF-κB/MAPK pathway

Cimifugin is an important component of chromones in the dry roots of Saposhikovia divaricata for treating inflammatory diseases. However, the possible effect of cimifugin in psoriasis needs further investigation. This current work was designed to evaluate the effects of cimifugin in psoriasis in vivo and in vitro, and unravel the underlying molecular mechanism. Here, we used imiquimod (IMQ) or tumor necrosis factor (TNF)-α to induce a psoriasis-like model in mice or keratinocytes. Obviously, the results showed that cimifugin reduced epidermal hyperplasia, psoriasis area severity index (PASI) scores, ear thickness and histological psoriasiform lesions in IMQ-induced mice. The decreased levels of reduced glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT), and the accumulation of malondialdehyde (MDA) in skin tissues by IMQ were attenuated by cimifugin. Furthermore, it was observed that cimifugin effectively reversed IMQ-induced up-regulation of proinflammatory cytokines, including TNF-α, IL-6, IL-1β, IL-17A, and IL-22. Mechanically, we noticed that cimifugin inhibited IMQ-activated phosphorylation of NF-κB (IκB and p65) and MAPK (JNK, ERK, and p38) signaling pathways. Similar alterations for oxidative stress and inflammation parameters were also detected in TNF-α-treated HaCaT cells. In addition, cimifugin-induced down-regulation of ICAM-1 were observed in TNF-α-treated cells. Altogether, our findings suggest that cimifugin protects against oxidative stress and inflammation in psoriasis-like pathogenesis by inactivating NF-κB/MAPK signaling pathway, which may develop a novel and effective drug for the therapy of psoriasis.

MTH1 Inhibitors for the Treatment of Psoriasis

Inflammatory diseases, including psoriasis, are characterized by changes in redox regulation. The MTH1 prevents the incorporation of oxidized nucleotides during DNA replication. Using MTH1 small-molecule inhibitors, we found induced apoptosis through 8-oxodeoxyguanosine triphosphate accumulation and DNA double-strand breaks after oxidative stress in normal and malignant keratinocytes. In psoriasis, we detected increased MTH1 expression in lesional skin and PBMCs compared with that in the controls. Using the imiquimod psoriasis mouse model, we found that MTH1 inhibition diminished psoriatic histological characteristics and normalized the levels of neutrophils and T cells in the skin and skin-draining lymph nodes. The inhibition abolished the expression of T helper type 17‒associated cytokines in the skin, which was in line with decreased levels of IL-17-producing γδ T cells in lymph nodes. In human keratinocytes, MTH1 inhibition prevented the upregulation of IL-17‒downstream genes, which was independent of ROS-induced apoptosis. In conclusion, our data support MTH1 inhibition using small molecules suitable for topical application as a promising therapeutic approach to psoriasis.

Oral dimethyl fumarate induces changes within the peripheral neutrophil compartment of patients with psoriasis that are linked with skin improvement

BACKGROUND

Dimethyl fumarate (DMF) is a treatment for moderate-to-severe psoriasis and multiple sclerosis. DMF therapy typically improves skin inflammation within the first 3 months of treatment. DMF is a prodrug that generates the hydroxycarboxylic acid receptor 2 (HCA2) agonist, monomethyl fumarate (MMF). Despite widespread clinical use, DMF's mechanism of action is not fully understood.

OBJECTIVES

We wished to characterize the changes induced by DMF in peripheral neutrophils within the first 3 months of treatment to better understand its early antipsoriatic effects.

METHODS

Flow cytometry was used to assess T-cell and neutrophil frequencies, apoptosis and activation phenotype. In vitro culture of neutrophils with DMF and MMF was used to evaluate apoptosis and HCA2 internalization. Serum levels of neutrophil degranulation products were measured by enzyme-linked immunosorbent assay.

RESULTS

Patients with psoriasis had significantly higher leucocyte counts at baseline compared with controls, with a large population of pro-inflammatory CD62L^lo  CD11b^bright neutrophils. Analysis revealed that DMF treatment reduced the frequency of CD62L^lo  CD11b^bright neutrophils and serum levels of neutrophil activation markers. This reduction was not linked to increased apoptosis.

CONCLUSIONS

Our results reveal a novel in vivo effect of DMF therapy on pro-inflammatory neutrophils that likely contributes to this treatment's antipsoriatic efficacy.

Luteolin as a modulator of skin aging and inflammation

Luteolin belongs to the group of flavonoids and can be found in flowers, herbs, vegetables and spices. It plays an important role in defending plants, for example against UV radiation by partially absorbing UVA and UVB radiation. Thus, luteolin can also decrease adverse photobiological effects in the skin by acting as a first line of defense. Furthermore, anti-oxidative and anti-inflammatory activities of luteolin were described on keratinocytes and fibroblasts as well as on several immune cells (e.g., macrophages, mast cell, neutrophils, dendritic cells and T cells). Luteolin can suppress proinflammatory mediators (e.g., IL-1β, IL-6, IL-8, IL-17, IL-22, TNF-α and COX-2) and regulate various signaling pathway (e.g., the NF-κB, JAK-STAT as well as TLR signaling pathway). In this way, luteolin modulates many inflammatory processes of the skin. The present review summarizes the recent in vitro and in vivo research on luteolin in the field of skin aging and skin cancer, wound healing as well as inflammatory skin diseases, including psoriasis, contact dermatitis and atopic dermatitis. In conclusion, luteolin might be a promising molecule for the development of topic formulations and systemic agents against inflammatory skin diseases.

Nutraceuticals against Oxidative Stress in Autoimmune Disorders

Antioxidant mechanisms are constituted of enzymes, endogenous, and non-enzymatic, exogenous, which have the role of counterbalancing oxidative stress. Intake of these compounds occurs in the diet. Vegetables, plants, and fruits contain a wide range of alkaloids, polyphenols, and terpenoids which are called “phytochemicals”. Most of these substances are responsible for the positive properties of fruits and vegetables, which are an essential part of a healthy life with roles in ameliorating chronic illnesses and favoring longevity. Nutraceuticals are substances contained in a food or fragment of it influencing health with positive effects on health helping in precenting or treating disorders. We conducted a review illustrating the principal applications of nutraceuticals in autoimmune disorders. Literature reported several studies about exogenous dietary antioxidant supplementation in diverse autoimmune diseases such as rheumatoid arthritis, lupus, diabetes, and multiple sclerosis. In these pathologies, promising results were obtained in some cases. Positive outcomes were generally associated with a reduction of oxidative stress parameters and a boost to antioxidant systems, and sometimes with anti-inflammatory effects. The administration of exogenous substances through food derivates or dietary supplements following scientific standardization was demonstrated to be effective. Further bias-free and extended studies should be conducted that include ever-increasing oxidative stress biomarkers.

The Differential Effect of Cannabidiol on the Composition and Physicochemical Properties of Keratinocyte and Fibroblast Membranes from Psoriatic Patients and Healthy People

The development of psoriasis is accompanied by oxidative stress, which can modify the components of skin cells. Therefore, the aim of this study was to evaluate the effect of cannabidiol (CBD), an antioxidant and anti-inflammatory phytocannabinoid, on the composition and physicochemical properties of the membranes of healthy and psoriatic keratinocytes and fibroblasts exposed to ultraviolet A (UVA) and ultraviolet B (UVB) radiation. In psoriasis-altered cells, decreased levels of the main groups of phospholipids and increased levels of sialic acid and malondialdehyde (MDA), a lipid peroxidation product, as well as negative charge of cell membranes compared to non-diseased cells, were found. On the other hand, UVA/B radiation increased the levels of phospholipids and MDA in both groups of cells. Moreover, psoriatic cells were characterized by lower levels of sialic acid and negative charge of cell membranes, while non-diseased cells showed the opposite response. The CBD treatment intensified some of the changes (phospholipid content and membrane charge) caused by the radiation of psoriatic cells, while it prevented these changes in the cells of healthy people. The results of this study indicate that CBD can prevent structural and functional changes to the membranes of healthy skin cells during phototherapy for psoriasis.

The emerging potential of cold atmospheric plasma in skin biology

The maintenance of skin integrity is crucial to ensure the physiological barrier against exogenous compounds, microorganisms and dehydration but also to fulfill social and aesthetic purposes. Besides the development of new actives intended to enter a formulation, innovative technologies based on physical principles have been proposed in the last years. Among them, Cold Atmospheric Plasma (CAP) technology, which already showed interesting results in dermatology, is currently being studied for its potential in skin treatments and cares. CAP bio-medical studies gather several different expertise ranging from physics to biology through chemistry and biochemistry, making this topic hard to pin. In this review we provide a broad survey of the interactions between CAP and skin. In the first section, we tried to give some fundamentals on skin structure and physiology, related to its essential functions, together with the main bases on cold plasma and its physicochemical properties. In the following parts we dissected and analyzed each CAP parameter to highlight the already known and the possible effects they can play on skin. This overview aims to get an idea of the potential of cold atmospheric plasma technology in skin biology for the future developments of dermo-cosmetic treatments, for example in aging prevention.

Gut-Brain-Skin Axis in Psoriasis: A Review

Introduction

Psoriasis is a common skin disease, with chronic inflammation and a complex etiology. It has long been recognized that chronic skin conditions and mental health disorders are often co-morbid. Thus, the concept of the gut–brain–skin axis emphasized in mental health disorders may also regulate the health of skin.

Results

The gut microbiota has been found to be the bridge between the immune system and nervous system. By leveraging clinical cases and animal models of psoriasis, an important communication pathway has been identified along the gut–brain–skin axis that is associated with the modulation of neurotransmitters from the microbiota. Furthermore, mammalian neurotransmitters, including dopamine, serotonin, or γ-aminobutyric acid (GABA), can be produced and/or consumed by several types of bacteria. Other studies suggest that manipulating these neurotransmitters by bacteria may have an effect on host physiology, and the levels of neurotransmitter can be altered by microbiota-based interventions.

Conclusions

Nonetheless, it is unknown whether or not the manipulation of neurotransmitter levels by bacteria can affect the occurrence and development of psoriasis. Notably, preliminary experiments found that oral consumption of probiotics improves the clinical symptoms in patients with psoriasis, perhaps correlated with the gut microbiome-mediated crosstalk between the immune system and the nervous system by secreting neurotransmitters in psoriasis. In this review, the communication along the gut–brain–skin axis is discussed.

Reduced Proteasome Activity and Enhanced Autophagy in Blood Cells of Psoriatic Patients

Psoriasis is a skin disease that is accompanied by oxidative stress resulting in modification of cell components, including proteins. Therefore, we investigated the relationship between the intensity of oxidative stress and the expression and activity of the proteasomal system as well as autophagy, responsible for the degradation of oxidatively modified proteins in the blood cells of patients with psoriasis. Our results showed that the caspase-like, trypsin-like, and chymotrypsin-like activity of the 20S proteasome in lymphocytes, erythrocytes, and granulocytes was lower, while the expression of constitutive proteasome and immunoproteasome subunits in lymphocytes was increased cells of psoriatic patients compared to healthy subjects. Conversely, the expression of constitutive subunits in erythrocytes, and both constitutive and immunoproteasomal subunits in granulocytes were reduced. However, a significant increase in the autophagy flux (assessed using LC3BII/LC3BI ratio) independent of the AKT pathway was observed. The levels of 4-HNE, 4-HNE-protein adducts, and proteins carbonyl groups were significantly higher in the blood cells of psoriatic patients. The decreased activity of the 20S proteasome together with the increased autophagy and the significantly increased level of proteins carbonyl groups and 4-HNE-protein adducts indicate a proteostatic imbalance in the blood cells of patients with psoriasis.

The Cutaneous Physiological Redox: Essential to Maintain but Difficult to Define

Skin is a unique tissue, possessing extremely efficient protective and regulative mechanisms, similar only to the gut and lungs. These tissues serve as an interface with the environment and are exposed to stressors from both endogenous and exogenous sources. Interestingly, all these stressors lead downstream to a cellular production of reactive oxygen species (ROS) and other electrophiles, which, in turn could have deleterious outcomes for the living organism. Hence, such tissues should always maintain a “high-alert” condition in order to cope with these various insults. Nevertheless, a moderate production of ROS induced by stressors could actually be beneficial, although it is impossible to predict if and which exposure would lead to which outcome. Consequently, a parameter which would indicate the skin’s readiness to cope with continuously fluctuating conditions is required. It has been proposed that the redox status may serve as a suitable indicator. In this opinion manuscript, we argue that the redox status is a vague parameter that is difficult to characterized and quantify due to its extremely dynamic nature. The common convention that the redox status is composed solely of the balance between oxidants and reductants (ROS and antioxidants) is also thought-provoking. Since this parameter in vivo behaves in a dynamic and complex manner, it better fits the description of a process, rather than an individual parameter. We suggest that the homeostatic modulation of the physiological redox (PR) should be in focus, rather than the redox status parameter itself. It is further suggested that low molecular weight antioxidants (LMWA) are, in fact, rather insignificant concerning the PR maintenance, and that the major contributors to this delicate modulation are regulative, protein-based systems such as the protective phase II antioxidant enzymes. Moreover, we show that skin microbiome and cutaneous advanced lipid peroxidation end-products (ALEs) take part in sustaining the cutaneous PR homoeostasis via activation of the Nrf2–Keap1 protective pathway.

Very low-calorie ketogenic diet (VLCKD) in patients with psoriasis and obesity: an update for dermatologists and nutritionists

Psoriasis is a chronic skin immune-mediated disease with systemic pro-inflammatory activation; both genetic and lifestyles factors contribute to its pathogenesis and severity. In this context, nutrition plays a significant role, per se, in psoriasis' pathogenesis. Obesity is another important risk factor for psoriasis, and weight reduction may improve psoriasis' clinical severity. The excess body weight, particularly visceral fat mass, can affect both drug's pharmacokinetics and pharmacodynamics. Therefore, psoriasis and obesity share a certain degree of synergy, and the chronic inflammatory state represents the basis of this vicious cycle. Evidence reported that nutrition has different impact on the clinical severity of psoriasis, though some specific diets have been more investigated in clinical studies compared to others. Diets with systemic anti-inflammatory properties seem to have a higher effect on improving the clinical severity of psoriasis. Of interest, very-low-calorie ketogenic diet (VLCKD), through the production of ketone bodies, has been associated with both a significant reduction of body weight and inflammatory state. VLCKD leading to both weight loss and reduction of systemic inflammation may decrease the exacerbation of the clinical manifestations or even it may block the trigger of psoriatic disease. This dietary pattern could represent a potential first-line treatment in psoriatic patients with obesity. The review aims to summarize the current evidence regarding VLCKD and psoriasis with specific reference to antioxidant and anti-inflammatory effects of this dietary pattern.

Cannabidiol Modifies the Formation of NETs in Neutrophils of Psoriatic Patients

Psoriasis is associated with increased production of reactive oxygen species which leads to oxidative stress. As antioxidants can provide protection, the aim of this study was to evaluate the effects of cannabidiol (CBD) on neutrophil extracellular trap (NET) formation in psoriatic and healthy neutrophils. Important markers of NETosis were measured in healthy and psoriatic neutrophils after incubation with CBD, lipopolysaccharide (LPS), and LPS + CBD). The percentage of neutrophils undergoing NETosis and the level of NETosis markers (cfDNA, MPO, elastase) were higher in the neutrophils and blood plasma of psoriatic patients, compared to controls. After LPS treatment, all of the markers of NETosis, except elastase, and p47 and citrullinated histones, were increased in samples from healthy subjects and psoriasis patients. CBD reduced the concentrations of NETosis markers. This led to a reduction in NETosis, which was more pronounced in psoriatic neutrophils and neutrophils treated with LPS in both psoriatic and healthy participants. These results suggest that psoriatic patients neutrophils are at a higher risk of NETosis both in vitro and in vivo. CBD reduces NETosis, mainly in psoriatic neutrophils, possibly due to its antioxidant properties. The anti-NET properties of CBD suggest the positive effect of CBD in the treatment of autoimmune diseases.

Oxidative Stress as an Important Contributor to the Pathogenesis of Psoriasis

This review discusses how oxidative stress (OS), an imbalance between oxidants and antioxidants in favor of the oxidants, increased production of reactive oxygen species (ROS)/reactive nitrogen species (RNS), and decreased concentration/activity of antioxidants affect the pathogenesis or cause the enhancement of psoriasis (Ps). Here, we also consider how ROS/RNS-induced stress modulates the activity of transcriptional factors and regulates numerous protein kinase cascades that participate in the regulation of crosstalk between autophagy, apoptosis, and regeneration. Answers to these questions will likely uncover novel strategies for the treatment of Ps. Action in the field will avoid destructive effects of ROS/RNS-mediated OS resulting in cellular dysfunction and cell death. The combination of the fragmentary information on the role of OS can provide evidence to extend the full picture of Ps.

Platelet Dysfunction and Its Role in the Pathogenesis of Psoriasis

BACKGROUND

Psoriasis is an immune-mediated inflammatory skin disease in conjunction with the systemic inflammatory process. It appears to be related to increased risks of cardiovascular disease events, especially in severe cases. The hemostatic balance is disrupted due to the prothrombotic bias in psoriasis, which might be mainly preserved by platelet hyperactivity. Platelets are also immune cells that initiate and regulate immune and inflammatory processes, except as the principal mediator of hemostasis and thrombosis, and platelet dysfunction is deeply involved in the pathogenesis of psoriasis.

SUMMARY

The aim of this study is to perform a review that expounds abnormal platelet function in psoriasis and explains the important role of platelets in the pathogenic mechanism of psoriasis in order to provide new targets for comprehensive medical treatment.

Cannabidiol Effects on Phospholipid Metabolism in Keratinocytes from Patients with Psoriasis Vulgaris

Psoriasis is a chronic inflammatory skin disease characterized by dysregulated keratinocyte differentiation, but oxidative stress also plays an important role in the pathogenesis of this disease. Here, we examined the effect of cannabidiol (CBD), a phytocannabinoid with antioxidant and anti-inflammatory properties, on the redox balance and phospholipid metabolism in UVA/UVB-irradiated keratinocytes isolated from the skin of psoriatic patients or healthy volunteers. CBD accumulates mainly in membrane keratinocytes, especially from patients with psoriasis. This phytocannabinoid reduces the redox imbalance observed in the UV-irradiated keratinocytes of healthy subjects. It does so by decreasing reactive oxygen species (ROS) generation, increasing the Trx-dependent system efficiency, and increasing vitamin A and E levels. Consequently, a reduction in lipid peroxidation products, such as 8-isoprostanes and 4-hydroxynonenal, was also observed. Moreover, CBD modifies redox balance and lipid peroxidation in psoriatic patient keratinocytes following UV-irradiation. Interestingly, these changes are largely in the opposite direction to the case of keratinocytes from healthy subjects. CBD also regulates metabolic changes by modulating the endocannabinoid system that is disturbed by psoriasis development and UV irradiation. We observed a decrease in anandamide level in the UV-irradiated keratinocytes of healthy controls following CBD treatment, while in keratinocytes from patients treated with CBD, anandamide level was increased. However, the level of palmitoylethanolamide (PEA) was decreased in both groups treated with CBD. We further demonstrate that CBD increases CB1 receptor expression, primarily in the keratinocytes of patients, and increases CB2 receptor expression in both the psoriatic and control groups. However, CBD decreases CB2 receptor expression in UV-irradiated keratinocytes taken from patients. The UV- and psoriasis-induced activity of transmembrane transporters (Multidrug-Resistance (MDR) and breast cancer resistance protein (BCRP)) is normalized after CBD treatment. We conclude that CBD partially reduces oxidative stress in the keratinocytes of healthy individuals, while showing a tendency to increase the oxidative and inflammatory state in the keratinocytes of patients with psoriasis, especially following UV-irradiation.

Oxidative Stress and Atopic Dermatitis

Atopic dermatitis is a common chronic/chronically relapsing inflammatory skin disease, with increasing worldwide prevalence. Etiopathogenesis is complex and multifactorial, with a mix of genetic, immunological and environmental aspects. Like in other chronic inflammatory diseases, oxidative stress plays an important pathogenetic role. We reviewed in vivo research studies on humans about oxidative stress and atopic dermatitis. Although sometimes contrasting, overall, they suggest that oxidative stress may have a significant role in atopic dermatitis, but our understanding is still incomplete, at least concerning in vivo data, because of limitations of available literature. Research consists of 33 papers published in 28 years, was not always performed on large study populations, represents a limited number of countries and ethnicities-not always in proportion to their size-and is scattered over multiple papers that, in the majority of cases, cannot be pooled and/or compared because many biomarkers were studied, in different tissues and with different methods. Further, larger studies appear warranted and necessary to shed more light on this aspect of atopic dermatitis, which is important not only to improve our understanding of this disease, but also for potential clinical and therapeutic implications.

Association between genetic polymorphisms of glutathione S-transferase M1/T1 and psoriasis in a population from the area of the strict of messina (Southern Italy)

Glutathione S-transferases (GST) are antioxidant enzymes with frequent genetic polymorphisms. Homozygosis for gene deletion ("null" genotype) of GSTM1 and GSTT1, causing decrease of the antioxidant potential of the organism, is frequent, with variable frequency in different ethnic contexts. Although oxidative stress notoriously plays a role in the pathogenesis of psoriasis, few studies exist on the association between GSTM1/GSTT1 genotype and psoriasis, with different results. We aimed to assess the frequency of GSTM1/GSTT1 polymorphisms in Southern Italian psoriatic patients and controls and investigate the association of the GSTM1/GSTT1 genotype with individual and disease parameters. To this aim, the GSTM1/GSTT1 genotype of 148 psoriatic patients and 148 age- and sex-matched controls was defined by PCR on oral mucosa cells. GSTT1 null was associated with psoriasis (55.4% of patients vs. 25% of controls, p = 9.58 × 10^-8, odds ratio 3.73), while GSTM1 null was not. The GSTM1/GSTT1 "double null" genotype conferred an even higher odds ratio for psoriasis (5.94). The association between psoriasis and GSTT1 null was stronger in women (54.1% of patients vs. 19.7% of controls, p = 8.13 × 10^-5) than in men (56.3% of patients vs. 28.7% of controls, p = 0.0002). No association was found between GSTM1/GSTT1 genotype and psoriasis severity, age of onset or comorbidities (psoriatic arthritis, metabolic syndrome). The remarkable differences among the few available data on the association between GSTM1/GSTT1 polymorphisms and psoriasis suggest the need for further studies, on different and larger populations, to improve knowledge on the pathogenesis of psoriasis and possibly provide more precise and personalised prevention and treatment in the future.