Review: A Contemporary, Multifaced Insight into Psoriasis Pathogenesis

Psoriasis is a chronic recurrent inflammatory autoimmune pathology with a significant genetic component and several interferences of immunological cells and their cytokines. The complex orchestration of psoriasis pathogenesis is related to the synergic effect of immune cells, polygenic alterations, autoantigens, and several other external factors. The major act of the IL-23/IL-17 axis, strongly influencing the inflammatory pattern established during the disease activity, is visible as a continuous perpetuation of the pro-inflammatory response and keratinocyte activation and proliferation, leading to the development of psoriatic lesions. Genome-wide association studies (GWASs) offer a better view of psoriasis pathogenic pathways, with approximately one-third of psoriasis's genetic impact on psoriasis development associated with the MHC region, with genetic loci located on chromosome 6. The most eloquent genetic factor of psoriasis, PSORS1, was identified in the MHC I site. Among the several factors involved in its complex etiology, dysbiosis, due to genetic or external stimulus, induces a burst of pro-inflammatory consequences; both the cutaneous and gut microbiome get involved in the psoriasis pathogenic process. Cutting-edge research studies and comprehensive insights into psoriasis pathogenesis, fostering novel genetic, epigenetic, and immunological factors, have generated a spectacular improvement over the past decades, securing the path toward a specific and targeted immunotherapeutic approach and delayed progression to inflammatory arthritis. This review aimed to offer insight into various domains that underline the pathogenesis of psoriasis and how they influence disease development and evolution. The pathogenesis mechanism of psoriasis is multifaceted and involves an interplay of cellular and humoral immunity, which affects susceptible microbiota and the genetic background. An in-depth understanding of the role of pathogenic factors forms the basis for developing novel and individualized therapeutic targets that can improve disease management.

Cholesterol and low-density lipoprotein as a cause of psoriasis: Results from bidirectional Mendelian randomization

BACKGROUND

Psoriasis is an inflammatory disease that affects many people. However, the causal effect of lipid metabolism on psoriasis has not yet been verified. This study aimed to identify the genetic relationship between serum lipid levels and psoriasis.

METHODS

Bidirectional two-sample Mendelian randomization (MR) was used to analyse the causal relationship between cholesterol and psoriasis. The outcome of the forward causality test was psoriasis. In the analysis of reverse causality, psoriasis was exposed, and 79 single-nucleotide polymorphisms were detected in the genome-wide association study (GWASs) database from the IEU GWASs Project. MR-Egger regression, inverse variance-weighted, weighted median, weighted mode and simple mode were used for the MR analyses.

RESULTS

The level of triglyceride, lipase member N, chylomicrons, extremely large very low-density lipoprotein (VLDL) particles, high-density lipoprotein (HDL) cholesterol levels, cholesterol esters in large HDL, cholesterol esters in medium HDL and cholesterol esters in medium VLDL have not affected the development of psoriasis. However, total cholesterol, total free cholesterol, low-density lipoprotein (LDL) cholesterol levels, cholesterol esters in large VLDL and cholesterol esters in medium LDL were unidirectional causal effects on psoriasis.

CONCLUSION

Bidirectional two-sample MR analysis indicated that high levels of total cholesterol, total free cholesterol, LDL cholesterol, cholesterol esters in large VLDL and cholesterol esters in medium LDL are genetic risk factors for psoriasis.

Adipose-Derived Stem Cell Exosomes Alleviate Psoriasis Serum Exosomes-Induced Inflammation by Regulating Autophagy and Redox Status in Keratinocytes

Introduction

Exosomes play a key role in cell communication and are involved in both pathological and physiological processes. Autophagy dysfunction and oxidative stress are linked to immune-mediated inflammatory diseases such as psoriasis. Stem cell-derived exosomes exhibit immunomodulatory and antioxidant efficacy.

Methods

We aimed to investigate the impact of psoriasis serum-derived exosomes on inflammation, oxidative stress, and autophagy in keratinocytes. Additionally, we explored the therapeutic potential of adipose-derived stem cell (ADSC) exosomes against inflammation induced by psoriasis serum exosomes. To validate psoriasis patient serum-derived exosomes and ADSC exosomes, we used nanoparticle tracking analysis, Western blotting, flow cytometry, and immunofluorescence. qPCR was used to study changes in the gene expression of proinflammatory cytokines and oxidative stress markers in HaCaT cells treated with psoriasis serum-derived exosomes or ADSC exosomes. The effects of these exosomes on autophagy in HaCaT cells were evaluated by Western blotting and immunofluorescence.

Result

The treatment of HaCaT cells with psoriasis serum-derived exosomes increased proinflammatory cytokine production and oxidative stress-related factor (Nox2 and Nox4) expression and decreased Nrf2 expression via P65/NF-κB and P38/MAPK activation. Compared with healthy control serum-derived exosomes, psoriasis serum-derived exosomes decreased ATG5, P62, Beclin1, and LC3 expression and autophagosome production in HaCaT cells. Conversely, ADSC exosomes suppressed proinflammatory cytokine and oxidative stress production, and restored autophagy in HaCaT cells treated with psoriasis serum-derived exosomes.

Discussion

These findings suggest that ADSC exosomes exhibit a suppressive effect on psoriasis serum exosome-induced inflammation and oxidative stress by regulating autophagy in keratinocytes.

miRNAs, Mesenchymal Stromal Cells and Major Neoplastic and Inflammatory Skin Diseases: A Page Being Written: A Systematic Review

Micro RNAs (miRNAs) are a type of non-coding RNA (ncRNA) and typically interact with specific target mRNAs through complementary base pairing, affecting their translation and/or stability. MiRNAs regulate nearly all cellular functions, including the cell fate of mesenchymal stromal cells (MSCs). It is now accepted that various pathologies arise at the stem level, and, in this scenario, the role played by miRNAs in the fate of MSCs becomes of primary concern. Here we have considered the existing literature in the field of miRNAs, MSCs and skin diseases, classified as inflammatory (such as psoriasis and atopic dermatitis-AD) and neoplastic (melanoma and non-melanoma-skin-cancer including squamous cell and basal cell carcinoma) diseases. In this scoping review article, the evidence recovered indicates that this topic has attracted attention, but it is still a matter of opinion. A protocol for this review was registered in PROSPERO with the registration number "CRD42023420245". According to the different skin disorders and to the specific cellular mechanisms considered (cancer stem cells, extracellular vesicles, inflammation), miRNAs may play a pro- or anti-inflammatory, as well as a tumor suppressive, or supporting, role, indicating a complex regulation of their function. It is evident that the mode of action of miRNAs is more than a switch on-off, and all the observed effects of their dysregulated expression must be checked in a detailed analysis of the targeted proteins. The involvement of miRNAs has been studied mainly for squamous cell carcinoma and melanoma, and much less in psoriasis and AD; different mechanisms have been considered, such as miRNAs included in extracellular vesicles derived both from MSCs or tumor cells, miRNAs involved in cancer stem cells formation, up to miRNAs as candidates to be new therapeutic tools.

Efficacy of hydrotherapy, spa therapy, and balneotherapy for psoriasis and atopic dermatitis: a systematic review

BACKGROUND

Atopic dermatitis (AD) and psoriasis are chronic inflammatory diseases that have significant skin complications.

OBJECTIVE

The purpose of this systematic study was to evaluate the evidence obtained from human studies on the effects of hydrotherapy, spa therapy, and balneotherapy in psoriasis and atopic dermatitis.

METHODS

The present systematic review was conducted according to the guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements. Also, for this study databases such as Embase, PubMed, Scopus ProQuest, and sciences direct database were searched from the beginning to April 2021.

RESULTS

All human studies that examined the effect of balneotherapy, spa therapy, and hydrotherapy on psoriasis and atopic dermatitis were published in the form of a full article in English. In the end, only 22 of the 424 articles met the criteria for analysis. Most studies have shown that balneotherapy, spa therapy, and hydrotherapy may reduce the effects of the disease by reducing inflammation and improving living conditions. In addition, the results of the Downs and Black score show that seven studies received very good scores, three studies received good scores, nine studies received fair scores, and three studies received poor scores.

CONCLUSIONS

The results of studies also showed that hydrotherapy leads to an improvement in the PASI score index. Nevertheless, more clinical trials are needed to determine the mechanism of action of hydrotherapy on these diseases.

Therapeutic potential of adipose tissue-derivatives in modern dermatology

Stem cell-mediated therapies in combination with biomaterial and growth factor-based approaches in regenerative medicine are rapidly evolving with increasing application beyond the dermatologic field. Adipose-derived stem cells (ADSCs) are the more frequently used adult stem cells due to their abundance and easy access. In the case of volumetric defects, adipose tissue can take the shape of defects, restoring the volume and enhancing the regeneration of receiving tissue. When regenerative purposes prevail on volume restoration, the stromal vascular fraction (SVF) rich in staminal cells, purified mesenchymal stem cells (MSCs) or their cell-free derivatives grafting are favoured. The therapeutic efficacy of acellular approaches is explained by the fact that a significant part of the natural propensity of stem cells to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines and extracellular matrix components. Therefore, the secretome's ability to modulate multiple targets simultaneously demonstrated preclinical and clinical efficacy in reversing pathological mechanisms of complex conditions such atopic dermatitis (AD), vitiligo, psoriasis, acne and Lichen sclerosus (LS), non-resolving wounds and alopecia. This review analysing both in vivo and in vitro models gives an overview of the clinical relevance of adipose tissue-derivatives such as autologous fat graft, stromal vascular fraction, purified stem cells and secretome for skin disorders application. Finally, we highlighted the major disease-specific limitations and the future perspective in this field.

Mesenchymal Stem Cells and Psoriasis: Systematic Review

Mesenchymal Stem Cells (MSCs) are multipotent non-hematopoietic stromal cells found in different body tissues such as bone marrow, adipose tissue, periosteum, Wharton's jelly, umbilical cord, blood, placenta, amniotic fluid, and skin. The biological behavior of MSCs depends mainly on their interaction with the microenvironment in which they are found, whose quality deeply influences the regenerative and immunomodulatory properties of these cells. Several studies confirm the interaction between MSCs and inflammatory microenvironment in the pathogenesis of psoriasis, designating MSCs as an important factor driving psoriasis development. This review aims to describe the most recent evidence on how the inflammatory microenvironment that characterizes psoriasis influences the homeostasis of MSCs and how they can be used to treat the disease.

Latest combination therapies in psoriasis: Narrative review of the literature

Biological therapies revolutionized the treatment of many chronic inflammatory skin diseases, first of all psoriasis, thanks to their high efficacy and the reduced number of side effects. However, the use of a single biologic drug does not always provide complete control of the disease or associated comorbidities over time. The first biological drugs used for the treatment of psoriasis, tumor necrosis factor alpha inhibitors, have long been used in combination with traditional topical and systemic therapies to induce a complete remission of the disease that could not be achieved with innovative drug alone. Even with the advent of new biological therapies with more precise molecular targets, the challenge of using combination therapies remained. Psoriatic patients often have major comorbidities, such as arthritis, inflammatory bowel disease, uveitis or have other concomitant conditions such as chronic spontaneous urticaria and atopic dermatitis, which may require different biologic treatments than those indicated in psoriasis. The objective of this article is, through a comprehensive revision of the literature, to analyze in which cases the use of the combination of the latest therapies for psoriasis may be useful.

Mesenchymal Stem Cells Profile in Adult Atopic Dermatitis and Effect of IL4-IL13 Inflammatory Pathway Inhibition In Vivo: Prospective Case-Control Study

Atopic dermatitis (AD) is an inflammatory disease that typically begins in childhood and may persist into adulthood, becoming a lifelong condition. The major inflammatory mediators of AD are known to be interleukin IL4 and IL13, so Dupilumab, which is able to inhibit both interleukins by blocking the shared IL4Rα subunit, has become an attractive option for treating AD. Mesenchymal stem cells (MSCs) are involved in the onset and development of AD by secreting specific interleukins. The aim of this study was to isolate MSCs from healthy controls (C-MSCs) and patients with AD before (AD-MSCs T0) and after 16 weeks of treatment with Dupilumab (AD-MSCs T16); to evaluate the expression mainly of IL4 and IL13 and of other inflammatory cytokines in C-MSCs, AD-MSCs at T0 and at T16; and to evaluate the efficacy of Dupilumab on MSCs immunobiology. C- and AD-MSCs (T0, T16) were isolated from skin specimens and characterized; the expression/secretion of IL4 and IL13 was evaluated using immuno-cytochemistry (ICC), indirect immune-fluorescence (IIF) and an ELISA test; secretion of IL2, IL4, IL5, IL6, IL10, IL12, IL13, IL17A, Interferon gamma (IFNγ), Tumor necrosis factor alpha (TNFα), Granulocyte Colony-Stimulating Factor (G-CSF), and Transforming Growth Factor beta1 (TGFβ1) were measured with ELISA. IL13 and IL6 were over-expressed, while IL4 was down-regulated in AD-MSCs at T0 compared to C-MSCs. IL6 and IL13 expression was restored after 16 weeks of Dupilumab treatment, while no significant effects on IL4 expression were noted. Finally, IL2, IL5, IL10, IL12, IL17A, INFγ, TNFα, G-CSF, and TGFβ1 were similarly secreted by C- and AD-MSCs. Although Dupilumab blocks the IL4Rα subunit shared by IL4 and IL13, it is evident that its real target is IL13, and its ability to target IL13 in MSCs reinforces the evidence, already known in differentiated cells, of the central role IL13 rather than IL4 in the development of AD. The inflammatory cascade in AD begins at the mesenchymal level, so an upstream therapeutic intervention, able to modify the immunobiology of atopic MSCs, could potentially change the natural history of the disease.

Stem cell therapy as a potential treatment option for psoriasis: a review

Psoriasis is a chronic inflammatory dermatological disorder characterized by white scales and clearly demarcated erythematous plaques. The prevalence of psoriasis varies from country to country and can occur at any age, implying that ethnicity, environmental factors, and genetic background all play a role in its onset. According to the World Psoriasis Day Consortium, 125 million people globally and 2%–3% of the overall community have psoriasis. The introduction of biological treatments has revolutionized the treatment of moderate to severe psoriasis. These novel drugs, particularly those targeting interleukin (IL)-17 and IL-23p19, can help most patients with psoriasis achieve clear or virtually clear skin with satisfactory durability. Nevertheless, none of these modern treatments are not entirely remedial in their current form, and alarmingly, a limited but growing proportion of patients with severe psoriasis are not responding satisfactorily to currently available treatments. Stem cell therapy, including regulatory T-cells, hematopoietic stem cell transplantation, and mesenchymal stromal cells, has been used in patients with recalcitrant psoriasis. This review discusses the stem cell treatments available for psoriasis.

Research update of adipose tissue-based therapies in regenerative dermatology

Mesenchymal stromal/stem cells (MSCs) have a spontaneous propensity to support tissue homeostasis and regeneration. Among the several sources of MSCs, adipose-derived tissue stem cells (ADSCs) have received major interest due to the higher mesenchymal stem cells concentration, ease, and safety of access. However, since a significant part of the natural capacity of ADSCs to repair damaged tissue is ascribable to their secretory activity that combines mitogenic factors, cytokines, chemokines, lipids, and extracellular matrix components, several studies focused on cell-free strategies. Furthermore, adipose cell-free derivatives are becoming more attractive especially for non-volumizing purposes, such as most dermatological conditions. However, when keratinocytes, fibroblasts, melanocytes, adipocytes, and hair follicle cells might not be locally sourced, graft of materials containing concentrated ADSCs is preferred. The usage of extracellular elements of adipose tissue aims to promote a self-autonomous regenerative microenvironment in the receiving area restoring physiological homeostasis. Hence, ADSCs or their paracrine activity are currently being studied in several dermatological settings including wound healing, skin fibrosis, burn, and aging.The present work analyzing both preclinical and clinical experiences gives an overview of the efficacy of adipose tissue-derivatives like autologous fat, the stromal vascular fraction (SVF), purified ADSCs, secretome and extracellular matrix graft in the field of regenerative medicine for the skin.

Mesenchymal Stem Cells Exposed to Persistently High Glucocorticoid Levels Develop Insulin-Resistance and Altered Lipolysis: A Promising In Vitro Model to Study Cushing's Syndrome

BACKGROUND

In Cushing's syndrome (CS), chronic glucocorticoid excess (GC) and disrupted circadian rhythm lead to insulin resistance (IR), diabetes mellitus, dyslipidaemia and cardiovascular comorbidities. As undifferentiated, self-renewing progenitors of adipocytes, mesenchymal stem cells (MSCs) may display the detrimental effects of excess GC, thus revealing a promising model to study the molecular mechanisms underlying the metabolic complications of CS.

METHODS

MSCs isolated from the abdominal skin of healthy subjects were treated thrice daily with GCs according to two different regimens: lower, circadian-decreasing (Lower, Decreasing Exposure, LDE) versus persistently higher doses (Higher, Constant Exposure, HCE), aimed at mimicking either the physiological condition or CS, respectively. Subsequently, MSCs were stimulated with insulin and glucose thrice daily, resembling food uptake and both glucose uptake/GLUT-4 translocation and the expression of LIPE, ATGL, IL-6 and TNF-α genes were analyzed at predefined timepoints over three days.

RESULTS

LDE to GCs did not impair glucose uptake by MSCs, whereas HCE significantly decreased glucose uptake by MSCs only when prolonged. Persistent signs of IR occurred after 30 hours of HCE to GCs. Compared to LDE, MSCs experiencing HCE to GCs showed a downregulation of lipolysis-related genes in the acute period, followed by overexpression once IR was established.

CONCLUSIONS

Preserving circadian GC rhythmicity is crucial to prevent the occurrence of metabolic alterations. Similar to mature adipocytes, MSCs suffer from IR and impaired lipolysis due to chronic GC excess: MSCs could represent a reliable model to track the mechanisms involved in GC-induced IR throughout cellular differentiation.

IgA Nephropathy in a Patient Treated with Adalimumab

Immunoglobulin A (IgA) nephropathy (IgAN) is the most common glomerulonephritis worldwide, characterized by IgA deposits in the glomerular mesangium. It has a progressive nature and can eventually lead to end-stage kidney failure. It can occur as a potential side effect of treatment with tumor necrosis factor alpha antagonist that has been used for numerous chronic inflammatory conditions, such as Crohn's disease. In this study, the case of a 33-year-old man with renal dysfunction, nephrotic proteinuria, and erythrocyturia is described. He had had a history of Crohn's disease for 8 years and had been treated with adalimumab for the past 7 years. The diagnosis of IgAN was confirmed by kidney biopsy. After discontinuance of adalimumab and the induction of corticosteroid therapy, he made a remarkable recovery. Four years after the first presentation of IgAN and discontinuation of adalimumab, his renal function was normal with no proteinuria and only mild erythrocyturia.

miRNAs Flowing Up and Down: The Concerto of Psoriasis

Psoriasis is a chronic immune-mediated skin disease, whose hallmarks include keratinocyte hyperproliferation and CD4⁺ T cell subsets imbalance. Dysregulated microRNAs (miRNAs) identified in psoriasis have been shown to affect keratinocyte and T cell functions, with studies on the molecular mechanisms and intrinsic relationships of the miRNAs on the way. Here, we focus on the dysregulated miRNAs that contribute to the two hallmarks of psoriasis with the miRNA target genes confirmed. We review a network, in which, upregulated miR-31/miR-203/miR-155/miR-21 and downregulated miR-99a/miR-125b facilitate the excessive proliferation and abnormal differentiation of psoriatic keratinocytes; upregulated miR-210 and downregulated miR-138 work in concert to distort CD4⁺ T cell subsets balance in psoriasis. The miRNAs exert their functions through regulating key psoriasis-associated transcription factors including NF-κB and STAT3. Whether flowing up or down, these miRNAs collaborate to promote the development and maintenance of psoriasis.

How the Pathological Microenvironment Affects the Behavior of Mesenchymal Stem Cells in the Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a chronic disease characterized by fibroblasts activation, ECM accumulation, and diffused alveolar inflammation. The role of inflammation in IPF is still controversial and its involvement may follow nontraditional mechanisms. It is seen that a pathological microenvironment may affect cells, in particular mesenchymal stem cells (MSCs) that may be able to sustain the inflamed microenvironment and influence the surrounding cells. Here MSCs have been isolated from fibrotic (IPF-MSCs) and control (C-MSCs) lung tissue; first cells were characterized and compared by the expression of molecules related to ECM, inflammation, and other interdependent pathways such as hypoxia and oxidative stress. Subsequently, MSCs were co-cultured between them and with NHLF to test the effects of the cellular crosstalk. Results showed that pathological microenvironment modified the features of MSCs: IPF-MSCs, compared to C-MSCs, express higher level of molecules related to ECM, inflammation, oxidative stress, and hypoxia; notably, when co-cultured with C-MSCs and NHLF, IPF-MSCs are able to induce a pathological phenotype on the surrounding cell types. In conclusion, in IPF the pathological microenvironment affects MSCs that in turn can modulate the behavior of other cell types favoring the progression of IPF.

Metabolic, pharmacokinetic, and toxicological issues of biologic therapies currently used in the treatment of hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa is a chronic, relapsing, debilitating inflammatory dermatologic disease of the terminal hair follicles at intertriginous sites clinically characterized by painful inflammatory nodules, abscesses, draining sinus tracts, and dermal fibrosis. The management of hidradenitis suppurativa is a challenge and usually consists of both medical and surgical approaches, which must often be combined for best outcome. The introduction of biological therapies, specifically TNFα-inhibitors such as adalimumab, has profoundly changed the therapeutic armamentarium of the disease.

AREAS COVERED

The PubMed database was searched using combinations of the following keywords: hidradentis suppurativa, biologic therapy, TNF-α inhibitors, adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, adverse effects, pharmacodynamics, pharmacology, adverse events, pharmacokinetics, drug interaction. This article reviews and updates the chemistry, pharmacokinetics, mechanism of action, adverse effects, drug interactions of on-label and off-label use of TNF-α inhibitors in HS.

EXPERT OPINION

Biologic agents, particularly adalimumab, exhibit clinical efficacy in patients with hidradenitis suppurativa. Careful patient selection and close monitoring during treatment are mandatory to provide safe and effective use of the TNF-α inhibitor. Familiarity with biologic agents is crucial because these agents could become a consolidated treatment option in the clinician's therapeutic approaches.

Adalimumab and methotrexate affect the concentrations of regulatory cytokines (interleukin-10, transforming growth factor-β1, and interleukin-35) in patients with plaque psoriasis

Dysfunctional regulatory T lymphocytes are important for the pathogenesis of psoriasis and atherosclerosis. We analyzed the severity of atherosclerosis and the concentration of regulatory cytokines in patients with psoriasis who were administered methotrexate or adalimumab for 12 weeks. We included 34 patients with psoriasis (17 each, administered methotrexate or adalimumab) and eight healthy volunteers. BMI, psoriasis area and severity index (PASI), body surface area (BSA), and at least 75% and 90% improvements in PASI were observed. The 10-year risk of fatal cardiovascular disease was estimated using Systematic Coronary Risk Evaluation charts. The plasma interleukin (IL)-10, IL-35, and transforming growth factor β1 (TGF-β1) levels were determined using enzyme-linked immunosorbent assay before and after the 12-week treatment regimen. PASI (P = .0006) and BSA (P = .0001) were positively correlated with the BMI, IL-35 (-0.38), and IL-10 (0.48) levels. Baseline IL-35 concentrations were the highest in healthy volunteers; the IL-10 and TGF-β1 level were the highest in the methotrexate group. IL-10 concentration decreased in both treatment groups (P = .02 for the methotrexate and P = .09 for adalimumab group), and IL-35 decreased in the adalimumab group (P = .019), consistent with skin lesion recovery. Thus, this study demonstrates the dysregulated secretion of regulatory cytokines in psoriatic patients under systemic treatment.

Mesenchymal stem cells for the treatment of psoriasis: a comprehensive review

Mesenchymal stem cells (MSCs) have recently been shown to have not only regenerative capabilities but also immunomodulating properties. For this reason, they are currently under investigation in clinical trials for the treatment of several autoimmune systemic disorders. Psoriasis is a systemic immune-mediated disease for which MSCs could have therapeutic potential. We analysed the existing literature with regard to MSC-based strategies for the treatment of psoriasis, using the MEDLINE, Embase, Scopus and Cochrane Library electronic databases from inception to the date of study. A number of studies confirm the involvement of MSCs in psoriasis pathogenesis and therefore designate MSCs as an important potential therapeutic tool in this setting. Preclinical data are mostly based on imiquimod-induced murine models of psoriasis, and confirm the anti-inflammatory and immunomodulatory action of MSCs in the setting of psoriasis. Six patients affected by psoriasis were described in four clinical studies. Despite significant differences in terms of therapeutic protocols and clinical outcomes, the MSC-based regimens were efficacious in 100% of the cases. Despite more data still being needed, MSCs could be a promising therapy for psoriasis.

Cytokines in psoriasis

Psoriasis is chronic, immune-mediated, inflammatory disease with a multifactorial etiology that affects the skin tissue and causes the appearance of dry and scaly lesions of anywhere on the body. The study of the pathophysiology of psoriasis reveals a network of immune cells that, together with their cytokines, initiates a chronic inflammatory response. Previously attributed to T helper (Th)1 cytokines, currently the Th17 cytokine family is the major effector in the pathogenesis of psoriatic disease and strongly influences the inflammatory pattern established during the disease activity. In addition, the vast network of cells that orchestrates the pathophysiology makes psoriasis complex to study. Along with this, variations in genes that code the cytokines make psoriasis more clinically heterogeneous and present a challenge for the development of drugs that can be used in the treatment of the patients with this disease. Therefore, it is important to clarify the mechanisms by which the cytokines are involved in the pathophysiology of psoriasis and how this knowledge is translated to the medical practice.

Safety update of etanercept treatment for moderate to severe plaque psoriasis

Introduction: Conventional topical therapies and disease-modifying anti-rheumatic drugs (DMARDs) for patients with psoriasis are often linked to inadequate outcomes and risk of multiple adverse effects. Biologic agents such as etanercept (ETN) have revolutionized the therapeutic management of psoriasis, allowing the treatment of most difficult cases, and fragile patients.Areas covered: The authors searched PubMed using the term 'psoriasis,' 'etanercept,' and 'safety.' Articles considered by the authors to be most relevant, such as randomized controlled studies, cohort studies, and review articles placing emphasis on studies of efficacy and safety were selected. Case reports and letters relating to safety were also included. The main sources of data referenced by these articles were also included in the review. Besides, to get the relevant studies, the reference lists were examined to identify the potentially available studies. The aim of this review is to describe the safety profile of ETN, used for psoriasis treatment, focusing on related clinical implications.Expert opinion: ETN has a favorable safety profile, and its use should be largely considered in psoriatic patients. Caution should be recommended in case of chronic heart failure, autoimmune disease, previous malignancies, familial history of demyelinating diseases, latent TBC infection, chronic HBV and HCV infection or HIV.

Mesenchymal Stromal Cells from the Epidermis and Dermis of Psoriasis Patients: Morphology, Immunophenotype, Differentiation Patterns, and Regulation of T Cell Proliferation

Psoriasis is a skin disease characterized by hyperproliferation of keratinocytes and chronic inflammation. Mesenchymal stem/stromal cells (MSCs) exhibit an immunoregulatory function that can be altered in the skin of these patients. However, to date, the presence and functional capacity of MSCs in the dermis and epidermis of patients with psoriasis have not been fully established. In the present study, we evaluated the presence of MSCs in the skin of patients by obtaining adherent cells from the dermis and epidermis of lesional and nonlesional areas and characterizing them in a comparative manner with corresponding cells obtained from the dermis (HD-MSCs) and epidermis (HE-MSCs) of healthy donors. We determined whether the adherent cells had immunophenotypic profiles and differentiation potentials that were characteristic of MSCs. In addition, we analyzed their immunosuppression function by evaluating their capacity to decrease T cell proliferation. Our results indicate the presence of MSCs in the dermis and epidermis of healthy donors and patients with psoriasis; adherent cells from all skin sources exhibited MSC characteristics, such as expression of CD73, CD90, and CD105 markers and a lack of hematopoietic and endothelial marker expression. However, the cell populations obtained showed differences in differentiation potential toward adipogenic, osteogenic, and chondrogenic lineages. In addition, we observed a low MSC obtention frequency in nonlesional epidermal samples (NLE-MSCs), which also showed alterations in morphology and proliferation rate. Interestingly, MSCs from both the nonlesional dermis (NLD-MSCs) and lesional dermis (LD-MSCs) showed higher HLA class I antigen (HLA-I) expression than HD-MSCs. Moreover, NLD-MSCs showed a low T cell proliferation suppression capacity. In summary, this study demonstrates the presence of MSCs in the epidermis and dermis of patients with psoriasis and suggests that such cells may favor the inflammatory process and thus psoriatic lesion development through high HLA-I expression and low immunosuppression capacity.

Mesenchymal Stem Cells: Allogeneic MSC May Be Immunosuppressive but Autologous MSC Are Dysfunctional in Lupus Patients

Mesenchymal stem cells (MSCs) have a potently immunosuppressive capacity in both innate and adaptive immune responses. Consequently, MSCs transplantation has emerged as a potential beneficial therapy for autoimmune diseases even though the mechanisms underlying the immunomodulatory activity of MSCs is incompletely understood. Transplanted MSCs from healthy individuals with no known history of autoimmune disease are immunosuppressive in systemic lupus erythematosus (SLE) patients and can ameliorate SLE disease symptoms in those same patients. In contrast, autologous MSCs from SLE patients are not immunosuppressive and do not ameliorate disease symptoms. Recent studies have shown that MSCs from SLE patients are dysfunctional in both proliferation and immunoregulation and phenotypically senescent. The senescent phenotype has been attributed to multiple genes and signaling pathways. In this review, we focus on the possible mechanisms for the defective phenotype and function of MSCs from SLE patients and summarize recent research on MSCs in autoimmune diseases.

Pharmacodynamics OF TNF α inhibitors for the treatment of psoriasis

Introduction: The treatment of psoriasis with conventional topical therapies and disease-modifying anti-rheumatic drugs (DMARDs) is often linked to unsatisfactory outcomes and the risk of serious adverse events. Over the last decades, research advances in understanding the role of tumor necrosis factor alpha (TNF α) and other cytokines in the pathogenesis of psoriasis have driven the introduction of biologic agents targeting specific immune mediators in everyday clinical practice. TNF α inhibitors are a consolidated treatment option for patients with moderate-to-severe disease with remarkable efficacy and a reassuring safety profile.Areas covered: The PubMed database was searched using combinations of the following keywords: psoriasis, TNF α inhibitors, biologic therapy, pharmacodynamics, adalimumab, etanercept, infliximab, certolizumab pegol, golimumab, adverse effects. The aim of this review is to describe the pharmacodynamic profile of anti-TNF α inhibitors, currently approved by the European Medicines Agency (EMA) for the treatment of psoriasis, focusing on related clinical implications, also in comparison to the new generation biological therapies targeting the interleukin 23/interleukin 17 axis.Expert opinion: Pharmacodynamics of TNF α inhibitors should be fully considered in planning patient's therapy strategies, especially in case of secondary failures, poor adherence to treatment, instable psoriasis, high risk of infection, pregnant or lactating women, metabolic comorbidities, coexistence of other immune-mediated inflammatory diseases.

Cushing Syndrome: The Role of MSCs in Wound Healing, Immunosuppression, Comorbidities, and Antioxidant Imbalance

Cushing syndrome (CS), caused by glucocorticoid (GCs) excess, is strictly connected to onset of different metabolic diseases and impaired wound healing. The source of excessively high levels of GCs allows the identification of endogenous and exogenous (iatrogenic) CS. Iatrogenic patients usually receive also anti-metabolites serving as the foundation to modern steroid-sparing immunosuppressive therapy. Tissues mainly targeted by CS are bone and fat, both derived from progenitor cells named mesenchymal stem cells (MSCs). In addition, the pathogenic role of MSCs in other diseases sharing common properties with CS, such as an altered inflammatory profile and increased oxidative stress, has been identified. In this light, MSCs isolated from skin of control healthy subjects (C-MSCs), patients affected by endogenous CS (ENDO-MSCs), patients affected by iatrogenic CS (IATRO-MSCs) and patients affected by exogenous CS receiving steroid-sparing drugs (SS-MSCs), respectively, have been isolated and analyzed. ENDO- and IATRO-MSCs showed a reduced differentiative potential toward osteogenic and adipogenic lineages compared to C-MSCs, whereas SS-MSCs re-acquired the ability to differentiate, with a trend similar to control cells. In addition, MSCs from CS groups, compared to control MSCs, displayed a reduction in the secretion of cytokines (immune-suppression), a decreased expression of genes related to wound healing and a dysregulation of the enzymes/genes related to antioxidant capacity. In conclusion, our results suggest that the hallmarks of CS, such as wound healing impairment and immunosuppression, are already detectable in undifferentiated cells, which could be considered a potential therapeutic early target for control of CS.

Stromal cells from perinatal and adult sources modulate the inflammatory immune response in vitro by decreasing Th1 cell proliferation and cytokine secretion

Many immune-mediated conditions are associated with a dysregulated imbalance toward a Th1 response leading to disease onset, severity, and damage. Many of the therapies such as immunomodulators or anti-TNF-α antibodies often fall short in preventing disease progression and ameliorating disease conditions. Thus, new therapies that can target inflammatory environments would have a major impact in preventing the progression of inflammatory diseases. We investigated the role of human stromal cells derived from the amniotic fluid (AFSCs), the placenta (PLSCs), and bone marrow-derived mesenchymal stromal cells (BM-MSCs) in modulating the inflammatory response of in vitro-stimulated circulating blood-derived immune cells. Immune cells were isolated from the blood of healthy individuals and stimulated in vitro with antigens to activate inflammatory responses to stimuli. AFSC, BM-MSCs, and PLSCs were cocultured with stimulated leukocytes, neutrophils, or lymphocytes. Inflammatory cytokine production, neutrophil migration, enzymatic degranulation, T cell proliferation, and subsets were evaluated. Coculture of all three stromal cell types decreased the gene expression of inflammatory cytokines and enzymes such as IL-1β, IFN-γ, TNF-α, neutrophil elastase, and the transcription factor NF-κB in lipopolysaccharide-stimulated leukocytes. With isolated phytohemagglutinin-stimulated peripheral blood mononuclear cells, cells coculture leads to a decrease in lymphocyte proliferation. This effect correlated with decreased numbers of Th1 lymphocytes and decreased secreted levels of IFN-γ.

Lentinan inhibits oxidative stress and inflammatory cytokine production induced by benzo(a)pyrene in human keratinocytes

BACKGROUND

Benzo(a)pyrene, a major environmental pollutant, is known to accelerate skin aging through oxidative stress, increase the production of inflammatory mediators, and cause skin cancer. Lentinan, prepared from Lentinus edodes (Shiitake mushroom), has been reported to exhibit anti-coagulant, anti-viral, anti-cancer, anti-tumor, and anti-coagulant effects. However, the effect of lentinan on human keratinocytes treated with benzo(a)pyrene is unknown.

AIMS

The aim of this study was to explore whether lentinan inhibits benzo(a)pyrene-induced oxidative stress and inflammatory cytokine production in human keratinocytes.

METHODS

We investigated the effect of lentinan on benzo(a)pyrene-induced oxidative stress indicators (malondialdehyde, superoxide dismutase, and glutathione peroxidase) in human immortalized keratinocytes (HaCaT cells). We also assessed the production of inflammatory factors interleukin-8 and chemokine ligand-2 induced by benzo(a)pyrene exposure at both mRNA and protein levels.

RESULTS

Lentinan inhibited oxidative stress induced by benzo(a)pyrene, as shown by the concentration-dependent reduction in reactive oxygen species in HaCaT cells. In addition, malondialdehyde levels were reduced to 53% of those of cells treated with benzo(a)pyrene without lentinan. The activities of superoxide dismutase and glutathione peroxidase were approximately 18- and 2.7-fold higher in benzo(a)pyrene-treated cells with lentinan than in those without lentinan. Moreover, lentinan significantly reduced interleukin-8 and chemokine ligand-2 mRNA and protein levels.

CONCLUSIONS

These findings suggest that lentinan has two biological activities that are potentially useful for managing inflammatory skin diseases or disorders related to oxidative stress induced by benzo(a)pyrene. Therefore, cosmetics containing L edodes have promising dermatological applications, with potential utility in protecting the skin against environmental pollutants.

Proinflammatory and anti-inflammatory cytokine profiles in psoriasis: use as laboratory biomarkers and disease predictors

OBJECTIVE

The objectives of this study were to delineate the pro and anti-inflammatory cytokine profiles of psoriasis and cytokine profile models that externally validate the diagnosis.

SUBJECTS AND METHODS

This study recruited 70 patients with psoriasis and 76 healthy controls. Cytokine profiles were evaluated, including pro-inflammatory M1 (IL-1 + IL-6 + TNF-α), Th1 (IL-2 + IL-12 + IFN-γ), Th17 (IL-6 + IL-17), and immune-inflammatory response system (IRS = M1 + Th1 + Th17) profiles. Moreover, the anti-inflammatory potential included Th2 (IL-4), Th2 + T regulatory (Th2 + Treg, namely IL-4 + IL-10 + TGF-β), anti-inflammatory (Th2 + Treg + adiponectin), and the pro-inflammatory/anti-inflammatory index.

RESULTS

There was a highly significant association between psoriasis and cytokine levels with an effect size of 0.829 and a particularly strong impact on IL-2 (0.463), IL-12 (0.451), IL-10 (0.532) and adiponectin (0.401). TGF-β and adiponectin were significantly lower while all other cytokines (except IFN-γ) were significantly higher in psoriasis than in controls. In addition, M1, Th1, Th17, Th2 + Treg, and IRS/Anti-inflammatory index were significantly higher in psoriasis patients than in controls. The IRS index, Th2 + Treg, and adiponectin predicted psoriasis with 97.1% sensitivity and 94% specificity.

CONCLUSION

In conclusion, psoriasis is characterized by increased M1, Th1, Th2 and Th17 profiles together with lowered TGF-β and adiponectin. In addition, we propose a model based on a higher IRS and Th2 + Treg index coupled with lower adiponectin values, which may be used to externally validate the diagnosis of psoriasis. The most important single biomarker of psoriasis is adiponectin. Because the latter may play a role in the modulation of the chronic inflammatory response in psoriasis, adiponectin could be a new drug target to treat psoriasis.

Indirect co-cultures of healthy mesenchymal stem cells restore the physiological phenotypical profile of psoriatic mesenchymal stem cells

Psoriasis microenvironment, characterized by an imbalance between T helper type 1 (Th1)/Th17 and Th2 cytokines and also influences the mesenchymal stem cells (MSCs) phenotypical profile. MSCs from healthy donors (H-MSCs) can exert a strong paracrine effect by secreting active soluble factors, able to modulate the inflammation in the microenvironment. To evaluate the influence of H-MSCs on MSCs from psoriatic patients (PsO-MSCs), H-MSCs and PsO-MSCs were isolated and characterized. Indirect co-culture of H-MSCs with PsO-MSCs was performed; effects on proliferation and expression of cytokines linked to Th1/Th17 and Th2 pathways were assayed before and after co-culture. The results show that before co-culture, proliferation of PsO-MSCs was significantly higher than H-MSCs (P < 0·05) and the levels of secreted cytokines confirmed the imbalance of Th1/Th17 versus the Th2 axis. After co-culture of H-MSCs with PsO-MSCs, healthy MSCs seem to exert a 'positive' influence on PsO-MSCs, driving the inflammatory phenotypical profile of PsO-MSCs towards a physiological pattern. The proliferation rate decreased towards values nearer to those observed in H-MSCs and the secretion of the cytokines that mostly identified the inflammatory microenvironment that characterized psoriasis, such as interleukin (IL)-6, IL-12, IL-13, IL-17A, tumour necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (G-CSF), is significantly lower in co-cultured PsO-MSCs than in individually cultured PSO-MSCs (P at least < 0·05). In conclusion, our preliminary results seem to provide an intriguing molecular explanation for the ever-increasing evidence of therapeutic efficacy of allogeneic MSCs infusion in psoriatic patients.

Perillaldehyde Inhibits AHR Signaling and Activates NRF2 Antioxidant Pathway in Human Keratinocytes

The skin covers the outer surface of the body, so the epidermal keratinocytes within it are susceptible to reactive oxygen species (ROS) generated by environmental pollutants such as benzo(a)pyrene (BaP), a potent activator of aryl hydrocarbon receptor (AHR). Antioxidant activity is generally mediated by the nuclear factor-erythroid 2-related factor-2 (NRF2) and heme oxygenase-1 (HO1) axis in human keratinocytes. Perillaldehyde is the main component of Perilla frutescens, which is a medicinal antioxidant herb traditionally consumed in East Asia. However, the effect of perillaldehyde on the AHR/ROS and/or NRF2/HO1 pathways remains unknown. In human keratinocytes, we found that perillaldehyde (1) inhibited BaP-induced AHR activation and ROS production, (2) inhibited BaP/AHR-mediated release of the CCL2 chemokine, and (3) activated the NRF2/HO1 antioxidant pathway. Perillaldehyde is thus potentially useful for managing inflammatory skin diseases or disorders related to oxidative stress.

Role of mesenchymal stem cells in the pathogenesis of psoriasis: current perspectives

Mesenchymal stem cells (MSCs) are multipotent nonhematopoietic stromal cells studied for their properties and importance in management of several skin diseases. This review collects and analyzes the emerging published data, which describe the function of MSCs in the pathogenesis of psoriasis.

Comparative analysis of molecular activity in dermal mesenchymal stem cells from different passages

Mesenchymal stem cells (MSCs) are used for tissue regeneration in several pathological conditions, including autoimmune diseases. However, the optimal sources and culture requirements for these cells are still under investigation. Here, we compared mRNA expression in dermal MSCs (DMSCs) at passage (P) 3 and P5 to provide a reference for future studies related to DMSCs expansion. In normal DMSCs, the expression of three of eight genes associated with basic cellular activity were different at P5 compared to that at P3: PLCB4 and SYTL2 were upregulated by 4.30- and 6.42-fold, respectively (P < 0.05), whereas SATB2 was downregulated by 39.25-fold (P < 0.05). At the same time, genes associated with proliferation, differentiation, inflammation, and apoptosis were expressed at similar levels at P3 and P5 (P > 0.05). In contrast, in DMSCs isolated from psoriatic patients we observed differential expression of three inflammation-associated genes at P5 compared to P3; thus IL6, IL8, and CXCL6 mRNA levels were upregulated by 16.02-, 31.15-, and 15.04-fold, respectively. Our results indicate that normal and psoriatic DMSCs showed different expression patterns for genes related to inflammation and basic cell activity at P3 and P5, whereas those for genes linked to proliferation, differentiation, and apoptosis were mostly similar.