VEGF, survivin and NOS overexpression in psoriatic skin: critical role of nitric oxide synthases

Role of antioxidants supplementation in the treatment of atopic dermatitis: a critical narrative review

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by itching, epidermal barrier dysfunction, and an unbalanced inflammatory reaction. AD pathophysiology involves a dysregulated immune response driven by T helper-2 cells. Many factors, including reactive oxygen species (ROS), are involved in AD pathogenesis by causing cellular damage and inflammation resulting in skin barrier dysfunction. This narrative review aims to provide a comprehensive overview of the role of natural molecules and antioxidant compounds, highlighting their potential therapeutic value in AD prevention and management. They include vitamin D, vitamin E, pyridoxine, Vitamin C, carotenoids, and melatonin. Some studies report a statistically significant association between antioxidant levels and improvement in AD, however, there are conflicting results in which antioxidant supplementation, especially Vitamin D, did not result in improvement in AD. Therefore, the clinical efficacy of these dietary nutritional factors in the treatment of AD needs to be further evaluated in clinical trials. Meanwhile, antioxidants can be incorporated into the management of AD patients in a personalized manner, tailored to the severity of the disease, comorbidities, and individual needs.

Topical and Systemic Retinoids in the Management of Hidradenitis Suppurativa: A Comprehensive Literature Review

Hidradenitis suppurativa (HS) is a debilitating chronic skin disorder characterized by painful inflammatory nodules, abscesses and sinus tracts involving intertriginous areas and has an adverse impact on patient quality of life. Over the past decade, the therapeutic options of HS have increased significantly to comprise multiple modalities, including topical medication, systemic therapies (mainly antibiotics, retinoids, and biologics), surgical approaches, and lifestyle modifications. Biologics alone or in combination with surgery remain the treatment of choice for moderate to severe disease. However, non-biologic therapies (including retinoids) may be used as monotherapy for mild disease and in combination with biologics and surgical treatment in moderate to severe disease. Retinoids, specifically isotretinoin, acitretin, and alitretinoin, are historically used in the management of HS, supported by anecdotal evidence and with variable treatment response. Although the current American and European guidelines offer different recommendations on the use of retinoids in HS, retinoids remain a valuable ally in HS management. This review provides a comprehensive analysis of the current scientific literature on retinoid therapy (topical and systemic) in HS, highlighting disparities in mechanisms of action, efficacy, and safety to clarify their role in HS treatment.

CT Patterns of Interstitial Lung Disease in Patients with Plaque Psoriasis: A Retrospective Case Series Study

Background and Objectives: Recently published articles reported an association between psoriasis and interstitial lung diseases (ILDs). The aim of this study is to evaluate the differences in ILD computed tomography (CT) patterns between smoker and never smoker plaque psoriasis (PP) patients under topical treatment without psoriatic arthritis (PA), inflammatory bowel disease (IBD) or connective tissue diseases (CTDs). Matherials and Methods: Two radiologists evaluated chest CT examinations of 65 patients (33 smokers, 32 never smokers) with PP. Results: Usual interstitial pneumonia (UIP) pattern was diagnosed in 36 patients, nonspecific interstitial pneumonia pattern in 19, hypersensitivity pneumonitis in 7 and pleuropulmonary fibroelastosis (PPFE) in 3 patients. UIP pattern showed a statistically significant higher frequency in smoker patients (p = 0.0351). Respiratory symptoms were reported in 80% of patients. Conclusions: ILDs seems to represent a new comorbidity associated with psoriasis. Moreover, a statistically significant association between smokers and UIP pattern in PP patients is found. Respiratory symptoms should be evaluated in PP patients, in collaboration with a radiologist and a pneumologist. However, further studies are required to better understand the epidemiology of ILDs in PP patients.

Systemic Antibiotic Therapy in Hidradenitis Suppurativa: A Review on Treatment Landscape and Current Issues

Hidradenitis suppurativa (HS) is a chronic, recurrent, and inflammatory skin disease characterized by painful, deep-seated, nodules, abscesses, and sinus tracts in sensitive areas of the body, including axillary, inguinal, and anogenital regions. Antibiotics represent the first-line pharmacological treatment of HS because of their anti-inflammatory properties and antimicrobial effects. This narrative review summarizes the most significant current issues on the role of systemic antibiotics in the management of HS, critically analyzing the main limits of their use (antibiotic resistance and toxicity). Although, in the last decades, several cytokines have been implicated in the pathomechanism of HS and the research on the use of novel biologic agents in HS has been intensified, antibiotics remain a valid therapeutic approach. Future challenges regarding antibiotic therapy in HS comprise their use in association with biologics in the management of acute flare or as a bridge therapy to surgery.

New Insight into the Molecular Pathomechanism and Immunomodulatory Treatments of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is an immune-mediated inflammatory disorder characterized by deep-seated nodules, abscesses, sinus tracts and scars localized in the intertriginous areas. It is accompanied by pain, malodourous secretion and a dramatically decreased quality of life. Although the pathogenesis has not been entirely elucidated, the primary event is follicular hyperkeratosis of the pilosebaceous apocrine unit. Since the registration of the tumor necrosis factor-alpha inhibitor Adalimumab in 2015, several cytokines have been implicated in the pathomechanism of HS and the research of novel therapeutic targets has been intensified. We provide an update on the inflammatory cytokines with a central role in HS pathogenesis and the most promising target molecules of future HS management.

Specific Activation of CB2R Ameliorates Psoriasis-Like Skin Lesions by Inhibiting Inflammation and Oxidative Stress

Psoriasis is a chronic inflammatory skin disease. Inflammation and oxidative stress play crucial roles in the pathogenesis of psoriasis. Cannabinoid receptor type 2 (CB2R) is an attractive target for treating various inflammatory disorders. However, the precise role and mechanism of CB2R activation in psoriasis remain to be further elucidated. In this study, imiquimod (IMQ)-induced experimental psoriasis mice and tumor necrosis factor-α (TNF-α)-activated keratinocytes (HaCaT) were used to examine the effect of CB2R activation on psoriasis-like lesions and the mechanism in vivo and in vitro. Our results demonstrated that activation of CB2R by the specific agonist GW842166X (GW) significantly ameliorated IMQ-induced psoriasiform skin lesions in mice by reducing epidermal thickness and decreasing plaque thickness. On the one hand, GW alleviated inflammation by decreasing inflammatory cytokines and abating inflammatory cell infiltration. On the other hand, this treatment reduced the level of iNOS and downregulated the expression of CB2R in psoriatic skin tissue. Further studies suggested that the Kelch-like ECH-associated protein 1/nuclear factor erythroid-2-related factor (Keap1/Nrf2) signaling pathway might be involved. Our findings reveal that selective activation of CB2R may serve as a new strategy for the treatment of psoriasis.

The Role of Diet in Children with Psoriasis: Emerging Evidence and Current Issues

Psoriasis is an immune-mediated inflammatory systemic disease with skin tropism and chronic relapsing course; it is associated with an increased cardiovascular risk and with many metabolic comorbidities, emerging during childhood in 22–33% of cases. Diet influences the presentation and the clinical course of inflammatory diseases, including psoriasis; in particular, it was shown that a Mediterranean, gluten-free, or low-calorie diet may positively affect disease control in adult patients with psoriasis and adequate pharmacological therapy. These three dietary regimens may play a role also in children with psoriasis. It has been demonstrated that pediatric psoriasis is associated with psychological stress, celiac disease, and obesity, which may be positively influenced by these dietary regimens, respectively. Therefore, the expertise of multiple health figures (gastroenterologists, nutritionists, pediatricians, dermatologists) is required to plan a tailor-made dietary strategy, ensuring good growth, through an adequate intake of essential micro- and macronutrients and, at the same time, impacting the pro-inflammatory biochemical profile and on the associated cardiovascular risk of psoriasis disease.

Vitiligo, from Pathogenesis to Therapeutic Advances: State of the Art

Vitiligo is an acquired hypopigmentation of the skin due to a progressive selective loss of melanocytes; it has a prevalence of 1-2% and appears as rounded, well-demarcated white macules. The etiopathology of the disease has not been well defined, but multiple factors contribute to melanocyte loss: metabolic abnormalities, oxidative stress, inflammation, and autoimmunity. Therefore, a convergence theory was proposed that combines all existing theories into a comprehensive one in which several mechanisms contribute to the reduction of melanocyte viability. In addition, increasingly in-depth knowledge about the disease's pathogenetic processes has enabled the development of increasingly targeted therapeutic strategies with high efficacy and fewer side effects. The aim of this paper is, by conducting a narrative review of the literature, to analyze the pathogenesis of vitiligo and the most recent treatments available for this condition.

MRSA and Skin Infections in Psoriatic Patients: Therapeutic Options and New Perspectives

Psoriatic patients present various infectious risk factors, but there are few studies in the literature evaluating the actual impact of psoriasis in severe staphylococcal skin infections. Our narrative review of the literature suggests that psoriatic patients are at increased risk of both colonization and severe infection, during hospitalization, by S. aureus. The latter also appears to play a role in the pathogenesis of psoriasis through the production of exotoxins. Hospitalized psoriatic patients are also at increased risk of MRSA skin infections. For this reason, new molecules are needed that could both overcome bacterial resistance and inhibit exotoxin production. In our opinion, in the near future, topical quorum sensing inhibitors in combination with current anti-MRSA therapies will be able to overcome the increasing resistance and block exotoxin production. Supplementation with Vitamin E (VE) or derivatives could also enhance the effect of anti-MRSA antibiotics, considering that psoriatic patients with metabolic comorbidities show a low intake of VE and low serum levels, making VE supplementation an interesting new perspective.

Biological Treatments for Pediatric Psoriasis: State of the Art and Future Perspectives

Psoriasis is a chronic systemic inflammatory disease that primarily affects the skin and is associated with multiple comorbidities with a considerable reduction in quality of life of affected patients. One-third of psoriasis cases begin in childhood and are associated with significant medical comorbidities such as obesity, metabolic syndrome, arthritis, and psychiatric disorders. In addition, because of its chronic nature and frequent relapses, psoriasis tends to require long-term treatment. Treatment of pediatric psoriasis usually involves the same methods used for adults. However, most treatments for pediatric psoriasis are used off-label, and research in this regard is still lacking. Targeted therapies involving the use of newly developed biologic drugs are also increasingly being applied to childhood psoriasis. This review summarizes the clinical features of pediatric psoriasis and focuses mainly on the updated concepts of pathogenesis and biological treatments of pediatric psoriasis.

Metabolic Comorbidities and Cardiovascular Disease in Pediatric Psoriasis: A Narrative Review

Psoriasis vulgaris is a common inflammatory, immune mediated, chronic recurrent dermatosis. Psoriasis is also a systemic inflammatory disease, associated with numerous comorbidities, particularly metabolic ones. Here, we summarize and discuss, in a narrative review, the current knowledge about the metabolic comorbidities in psoriatic children. Obesity, insulin resistance, diabetes, cardiovascular disease, and dyslipidemia are identified as the main comorbidities in psoriatic children. In conclusion, dermatologists should be aware of the metabolic comorbidities in children with psoriasis, modulating the therapeutic approach according to the patient’s clinical condition.

Serum levels of survivin in patients with psoriasis and their relation to disease characteristics

BACKGROUND

Psoriasis is a chronic inflammatory disease in which T helper 1 (Th1) and Th17 cells play a major role in its pathogenesis. Studies have shown that keratinocytes in psoriatic tissue are resistant to apoptosis and have a high proliferation rate. Survivin is a multifunctional protein belonging to an apoptosis inhibitor family, which has significant effects on the immune system, such as activation of dendritic cells and T cells and immunomodulation.

OBJECTIVES

To investigate a possible relationship between serum survivin levels and psoriasis disease characteristics and severity.

MATERIALS AND METHODS

The present study included 84 patients with psoriasis who did not receive any systemic treatment for psoriasis in the last three months and 84 volunteers without psoriasis. Demographic data, smoking status, and alcohol consumption of the participants were questioned, and body mass index (BMI) was calculated. In the patient group, disease duration, family history, accompanying arthritis, and nail involvement were questioned and psoriasis area severity index (PASI) scores were calculated. Serum survivin levels were measured in all subjects.

RESULTS

Serum survivin level was significantly higher in the patients compared to the controls (p = 0.008). There was no relationship between serum survivin level and disease duration, family history, joint involvement, nail involvement, BMI, and PASI score (all p-values > 0.05). Serum survivin levels were significantly higher in smokers than non-smokers and in alcohol consumers than patients that did not drink alcohol in the psoriasis group (p = 0.034 and p = 0.006, respectively).

CONCLUSION

Serum survivin levels were higher in psoriasis patients than the control group. This finding suggests that this molecule, which is both immunomodulatory and an apoptosis inhibitor, may play a role in the pathogenesis of psoriasis. Significantly high serum survivin level in psoriasis patients who smoke suggests that smoking may act through survivin. More comprehensive studies are needed to evaluate the role of survivin in the pathogenesis of psoriasis and its relationship with smoking.

Safety and Efficacy of Vaccines during COVID-19 Pandemic in Patients Treated with Biological Drugs in a Dermatological Setting

The BNT162b2 and mRNA-1273 vaccines, consisting of mRNA, have recently become available. The absolute novelty of these vaccines introduces questions about their safety and efficacy, especially in patients who are treated with biological drugs in dermatology. The aim of our review was to provide a broad overview of the current use of all available vaccinations in concomitance with biological therapy and to suggest indications for the new mRNA Covid-19 vaccines. We conducted a narrative review of the literature regarding the indications and safety of the various types of vaccines currently available in dermatological patients treated with biological therapy. The safety and efficacy of administering inactivated vaccines in patients undergoing biological therapy with inhibitors of TNF-α, IL-17, IL-12/23, and IL-4/13 was confirmed. Inactivated vaccines can be administered during therapy with inhibitors of IL-23 and IgE, taking into account that the level of evidence is lower due to the lack of specific studies. Live attenuated vaccines were contraindicated in concomitance with all biological therapies considered, except omalizumab. According to this evidence, we assume that there are currently no contraindications to the administration of the new Covid-19 BNT162b2 and mRNA-1273 vaccines during biological therapy with inhibitors of TNF-α, IL-17, IL-12/23, IL-23, and IL-4/13, since these vaccines are comparable to inactivated ones. For patients with chronic urticaria or allergic asthma treated with omalizumab, we currently recommend caution in using the mRNA Covid-19 vaccines (30 min observation). The only contraindications were a previous history of hypersensitivity to the Covid-19 vaccines themself or to their excipients. In conclusion, further randomized clinical trials are needed to evaluate the efficacy of the antibody response in these patients.

More than skin deep: using polymers to facilitate topical delivery of nitric oxide

Skin, the largest organ in the human body, provides several important functions, including providing protection from mechanical impacts, micro-organisms, radiation and chemicals; regulation of body temperature; the sensations of touch and temperature; and the synthesis of several substances including vitamin D, melanin, and keratin. Common dermatological disorders (CDDs) include inflammatory or immune-mediated skin diseases, skin infection, skin cancer, and wounds. In the treatment of skin disorders, topical administration has advantages over other routes of administration, and polymers are widely used as vehicles to facilitate the delivery of topical therapeutic agents, serving as matrices to keep therapeutic agents in contact with the skin. Nitric oxide (NO), a cellular signalling molecule, has attracted significant interest in treating a broad spectrum of diseases, including various skin disorders. However, there are a number of challenges in effectively delivering NO. It must be delivered in a controlled manner at sufficient concentrations to be efficacious and the delivery system must be stable during storage. The use of polymer-based systems to deliver NO topically can be an effective strategy to overcome these challenges. There are three main approaches for incorporating NO with polymers in topical delivery systems: (i) physical incorporation of NO donors into polymer bases; (ii) covalent attachment of NO donors to polymers; and (iii) encapsulation of NO donors in polymer-based particles. The latter two approaches provide the greatest control over NO release and have been used by numerous researchers in treating CDDs, including chronic wounds and skin cancer.

Impact of smoking on psoriasis risk and treatment efficacy: a meta-analysis

Objective

Psoriasis is an immune-mediated chronic inflammatory disease with skin and joint manifestations. Smoking is considered an unfavorable lifestyle factor for psoriasis. We aimed to explore the association between smoking, disease risk, and treatment efficacy in relation to psoriasis.

Methods

We searched the Cochrane Library, Embase, and PubMed databases for studies examining the relationship between smoking and psoriasis, up to 12 April 2020. We then conducted a meta-analysis using a fixed-effects model to obtain odds ratios (ORs) with 95% confidence intervals (CIs).

Results

Ever, current, and former smokers all had higher risks of developing psoriasis than non-smokers (pooled ORs (95% CIs): 1.60 (1.51–1.69), 1.63 (1.48–1.80), and 1.36 (1.13–1.64), respectively). Ever smokers were less likely to show disease improvement at 6 months following treatment with biologic agents than non-smokers (pooled OR (95% CI): 0.80 (0.67–0.95)).

Conclusions

Smoking increases psoriasis risk and negatively impacts the benefits of biologic agents. However, the number of reports is limited and more studies are needed to confirm the effects of smoking and smoking cessation on therapeutic response in patients with psoriasis. Education to encourage a healthy lifestyle remains a valuable approach in clinical practice.

Expression of Vascular Endothelial Growth Factor and Microvessel Density in Psoriatic Skin Lesions

Background:

Psoriasis is a common chronic and immune-mediated skin disorder having a significant impact on the patient's quality of life. An analysis of the role of angiogenic vascular endothelial growth factor (VEGF) expression and microvessel density in psoriatic skin lesions may help in better understanding of the disease pathogenesis. The aim of this study was to examine the expression of vascular endothelial growth factor (VEGF) and microvessel density using CD34 antibodies in psoriatic skin lesions by immunohistochemical examination using normal skin of healthy individuals as controls.

Materials and Methods:

Patients with clinical diagnosis of plaque type of psoriasis (e.g., chronic plaque) (n = 49) were included in the study. 5-mm punch biopsies were taken from the psoriatic skin lesions in these patients. A total of 20 punch biopsies were taken from the control group comprising of 20 healthy volunteers. The biopsies were subjected to histopathological examination for confirmation of diagnosis and grading. Immunohistochemical evaluation was done for the expression of VEGF, and microvessel density was assessed using CD34 and compared with the controls.

Results:

An increased VEGF expression by keratinocytes (49.80% ± 21.16%) and microvessel density in the papillary dermis (15.302% ± 3.8061%) was observed in patients with psoriasis, which was significantly higher as compared to controls (P < 0.0001). A significant positive correlation was observed between VEGF expression by keratinocytes and the microvessel density in the dermis (r = 0.664, P = 0.01). No significant correlation was observedbetween the histopathological grade of psoriasis and microvessel density, or with the VEGF expression.

Conclusion:

VEGF expression ascertained to be a significant factor in the pathogenesis of psoriasis.

[Expressions of survivin, PI3K and AKT in keratinocytes in skin lesions and their pathogenic role in psoriasis vulgaris]

OBJECTIVE

To explore the role of survivin and PI3K/AKT pathway in the pathogenesis of psoriasis vulgaris (PV).

METHODS

Plaque-like lesions collected from 22 patients with PV in progressive stage and 18 normal control skin specimens were examined using immunohistochemical staining, Western blotting and real-time quantitative PCR for expressions of survivin, PI3K and AKT in the keratinocytes, and their correlation was analyzed. A small interfering RNA (siRNA) was used to knock down AKT in cultured HaCaT cells, and Western blotting was used to detect the changes in the expression of survivin. RESULTS Compared with normal skin, PV lesions showed obviously up-regulated expressions of survivin, PI3K and AKT in the keratinocytes. Survivin expression was positively correlated with PI3K (r=0.4510, P=0.0351) and AKT (r=0.4423, P=0.0393) in the keratinocytes in PV lesions. In cultured HaCaT cells, siRNA-mediated knockdown of AKT caused down-regulation of survivin expression.

CONCLUSION

Survivin and PI3K/AKT signaling pathway may participate in the occurrence and progression of PV.

Immunobiology of Nitric Oxide and Regulation of Inducible Nitric Oxide Synthase

Nitric oxide (NO) is a bioactive gas that has multiple roles in innate and adaptive immune responses. In macrophages, nitric oxide is produced by inducible nitric oxide synthase upon microbial and cytokine stimulation. It is needed for host defense against pathogens and for immune regulation. This review will summarize the role of NO and iNOS in inflammatory and immune responses and will discuss the regulatory mechanisms that control inducible nitric oxide synthase expression and activity.

Angiogenesis and lymphangiogenesis in inflammatory skin disorders

Angiogenesis, the growth of new blood vessels from pre-existing vessels, occurs physiologically in wound healing, during inflammatory diseases, and in tumor growth. Lymphangiogenesis can be activated in inflammation and tumor metastasis. The family of vascular endothelial growth factors (VEGFs) and angiopoietins are essential for angiogenesis and lymphangiogenesis. The angiogenic process is tightly regulated by VEGFs, angiopoietins, and endogenous inhibitors. VEGFs and angiopoietins exert their effects by activating specific receptors present on blood and lymphatic endothelial cells. There is now compelling evidence that cells of innate and adaptive immunity (macrophages, mast cells, neutrophils, eosinophils, lymphocytes) are a major source of angiogenic and lymphangiogenic factors. Chronic inflammatory skin diseases such as psoriasis and atopic dermatitis are characterized by altered angiogenesis, lymphangiogenesis, or both. Also such acute inflammatory skin disorders as urticaria, ultraviolet B-induced damage, and angioedema are associated with changes in angiogenic factors. In systemic sclerosis there is a switch from proangiogenic to antiangiogenic factors that play a role in the defective vascular process of this disorder. As yet, there are no clinical trials showing that canonical VEGF/VEGF receptor-targeted strategies can modulate inflammatory skin diseases. Novel strategies targeting other angiogenic/lymphangiogenic pathways should also be investigated.

VEGF-A promotes IL-17A-producing γδ T cell accumulation in mouse skin and serves as a chemotactic factor for plasmacytoid dendritic cells

BACKGROUND

IL-17-producing CD4(+) T (Th17) cells and their cytokines, IL-17A and IL-22, are deeply involved in the pathogenesis of psoriasis by stimulating epidermal keratinocytes to proliferate and to produce cytokines/chemokines and vascular endothelial growth factor (VEGF)-A. Plasmacytoid dendritic cells (pDCs), infiltrating in psoriatic lesions, are known to exacerbate the Th17-mediated pathogenesis of psoriasis.

OBJECTIVE

To address the initiative role of VEGF-A in the development of psoriasis and the pDC accumulation.

METHODS

Numerical changes and VEGF receptor 1 (VEGFR1) and VEGFR2 expressions were investigated in skin-infiltrating T cells and pDCs of K14-VEGF-A transgenic (Tg) and wild type (WT) mice. The chemotactic properties of VEGF-A for purified splenic pDCs were also evaluated by real-time chemotaxis assay.

RESULTS

By flow cytometry and immunohistochemistry, we observed that the number of dermal IL-17A(+) γδ T cells, but not CD4(+) T cells, was increased in VEGF-A Tg mice, suggesting that the main source of IL-17A was γδ T cells. Moreover, we identified pDCs as 440c(+) cells by immunohistochemistry and as PDCA-1(+)B220(+) cells by flow cytometry, and found that pDCs infiltrated at a higher frequency in VEGF-A Tg than WT mice. pDCs, but not γδ T cells, isolated from the skin expressed VEGFR1 and VEGFR2. Freshly isolated splenic pDCs expressed both receptors after 48-h cultivation. pDCs did not produce cytokines in response to VEGF-A, however, they had a strong velocity of chemotaxis toward VEGF-A at a comparable level to chemerin.

CONCLUSIONS

These findings suggest that VEGF-A functions as not only a downstream enhancer but also an upstream initiator by chemoattracting pDCs in psoriatic lesions.

Expression of nuclear factor kappa B and survivin in psoriasis

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

Smoking and pathogenesis of psoriasis: a review of oxidative, inflammatory and genetic mechanisms

Recent studies suggest that cigarette smoking may trigger the development of psoriasis through oxidative, inflammatory and genetic mechanisms. Smoking initiates formation of free radicals that stimulate cell signalling pathways active in psoriasis including mitogen-activated protein kinase (MAPK), nuclear factor-κB (NF-κB) and Janus kinase/signal transducers and activators of transcription (JAK-STAT). Smoking damages the skin by increasing formation of reactive oxygen species and decreasing the gene expression of antioxidants. Nicotine also stimulates innate immune cells integral to the pathogenesis of psoriasis including dendritic cells, macrophages and keratinocytes. These cells release cytokines that activate T lymphocytes and perpetuate a cycle of chronic inflammation. Smoking also enhances expression of genes known to confer an increased risk of psoriasis, including HLA-Cw6, HLA-DQA1*0201 and CYP1A1. Improved understanding of the possible link between smoking and psoriasis pathogenesis may provide further insight into mechanisms underlying smoking, psoriasis and risk of subsequent cardiovascular disease.

Survivin: a dual player in healthy and diseased skin

Survivin belongs to the inhibitor of apoptosis (IAP) protein family, and, in addition to the antiapoptotic functions, it also regulates the cell cycle. The survivin gene generates five major isoforms with diverse and opposite functions. Survivin is highly expressed in cancer and in few normal adult tissues, including skin. It is mostly detected in the nucleus of keratinocyte stem cells (KSCs), but it is also expressed in melanocytes and fibroblasts. Survivin isoforms are differentially detected in subpopulations of human keratinocytes, exerting contrasting activities. Survivin has an important role in the regulation of cell cycle in keratinocytes, and it protects these cells from anoikis and UV-induced apoptosis. In melanoma, survivin is abundantly expressed, and its subcellular localization varies depending upon tumor thickness and invasiveness. Survivin overexpression has been shown in squamous cell carcinoma (SCC), and it is also involved in UVB-induced carcinogenesis. The presence of survivin both in the nucleus and in the cytoplasm throughout the epidermal layers of psoriatic lesions suggests the involvement of this protein in the keratinocyte alterations typical of this disease. Additional studies on the expression of survivin isoforms and their subcellular localization in relation to function will confirm the key role of survivin in the skin and will open the field to new therapeutic strategies for many cutaneous conditions.