Search Results (25)

Psoriasis is a chronic immune-mediated inflammatory skin disorder characterized by excessive keratinocyte proliferation, oxidative stress, and dysregulated cytokine signaling. Although topical corticosteroids remain the first-line therapy, their long-term use is often limited by adverse effects, highlighting the need for safer non-steroidal therapeutic alternatives. This study investigated the therapeutic efficacy and underlying mechanisms of a topical astaxanthin (AST) formulation in an imiquimod (IMQ)-induced mouse model of psoriasiform dermatitis. Following IMQ induction, mice were randomly assigned to vehicle, clobetasol, or AST treatment groups (0.5–1.5%) for 14 days. Disease progression was evaluated through biochemical analysis of oxidative stress biomarkers, including NADPH oxidase (NOX), malondialdehyde (MDA), nitric oxide (NO), and superoxide dismutase (SOD), as well as ELISA-based quantification of inflammatory cytokines (TNF-α, IL-6, IL-17, and IL-23). Histopathological changes were assessed using hematoxylin and eosin staining, while molecular alterations were examined by RT-qPCR analysis of psoriasis-associated keratin genes (Krt16, Krt17, and Krt6a) and evaluation of JAK–STAT signaling activity. AST treatment significantly suppressed the IL-23/IL-17 inflammatory axis, reduced NOX activity and lipid peroxidation, restored endogenous antioxidant defenses, and inhibited JAK–STAT signaling. These biochemical and molecular effects were accompanied by marked downregulation of keratin gene expression and substantial histological improvement, including normalization of epidermal thickness, reduced parakeratosis, and decreased inflammatory infiltration. Notably, high-dose AST demonstrated therapeutic efficacy comparable to, and in some parameters exceeding, that of clobetasol. Collectively, these findings indicate that topical astaxanthin exerts coordinated antioxidant, anti-inflammatory, and anti-proliferative effects, supporting its potential as a promising multi-target non-steroidal therapeutic candidate for psoriasis management. Full article

Obesity is an important risk factor for psoriasis, and clinical studies indicate that exercise interventions can improve disease severity. However, the mechanisms by which exercise influences psoriatic pathogenesis remain insufficiently understood. To investigate the effects of aerobic exercise on obesity-associated psoriasis, wild-type mice were fed a high-fat diet (HFD) for 7 weeks to induce obesity and subsequently underwent moderate-intensity treadmill running for 3 weeks. Psoriasiform dermatitis was induced by daily topical application of imiquimod (IMQ) to the skin for five consecutive days. HFD increased body weight, epididymal fat mass, and serum cholesterol. HFD-fed mice developed more severe IMQ-induced psoriatic skin changes compared with normal diet-fed mice. Treadmill exercise modestly reduced body weight gain and attenuated epidermal hyperplasia in HFD-fed mice. In contrast, inflammatory cytokine expression, including Tnfa, Il17a, and Il23a, showed modest increases in the skin of HFD-fed exercised mice, which did not parallel the improvement in epidermal hyperplasia. Overall, these findings indicate that while obesity exacerbates psoriasiform dermatitis, aerobic exercise ameliorates epidermal hyperplasia in obese mice without corresponding changes in inflammatory cytokine expression in the skin, suggesting that exercise may influence psoriatic skin changes through multiple metabolic and immunological pathways. Full article

Background and Clinical Significance: MSMO1, encoding a key enzyme in the cholesterol synthesis pathway, is associated with an autosomal recessive condition characterized by microcephaly, ocular abnormalities, growth delay, psoriasiform dermatitis, immune dysfunction, and intellectual disability. Case Presentation: This report describes a patient presenting with global developmental delay and bilateral infantile cataracts found to harbor a homozygous likely pathogenic MSMO1 variant and reviews the literature on MSMO1 deficiency and its association with infantile cataracts. Conclusions: The mechanism of early lens opacification is thought to result from impaired cholesterol synthesis, altering the lipid composition of the lens membrane and leading to early cataract formation. This case expands our understanding of MSMO1 deficiency and highlights the critical role of cholesterol biosynthesis in early lens development. Full article

Psoriasis is a chronic inflammatory skin disease driven by the IL-23/IL-17 axis and characterized by keratinocyte hyperproliferation, epidermal thickening, and immune infiltration. While immune cell-intrinsic roles of hypoxia-inducible factor-1α (HIF-1α) have been reported, the contribution of keratinocyte HIF-1α remains less clear. In this study, we investigated epithelial HIF function in murine models of skin inflammation using keratinocyte-specific HIF-1α knockout (K14-Cre Hif1a^fl/fl) mice. HIF-1α deficiency attenuated epidermal hyperplasia and type 3 inflammation in the imiquimod (IMQ)-induced psoriasiform model but had little effect in DNFB-induce contact hypersensitivity and MC903-induced atopic dermatitis model. Flow cytometry of draining lymph nodes revealed reduced frequencies of inflammatory cells including IL-17-producing γδ T cells in HIF-1α-deficient mice. In IMQ-treated skin, HIF-1α deficiency led to reduced Il17, Il23 and neutrophil-attracting chemokine transcript levels and diminished Ly6G⁺ neutrophil infiltration. These findings identify keratinocyte HIF-1α as a central regulator of psoriasiform inflammation and suggest that epithelial HIF signaling could be a potential therapeutic target for psoriasis. Full article

Psoriasis and allergic contact dermatitis (ACD) are the most common chronic inflammatory diseases, which are accompanied by epithelial alterations and a T cell-mediated immunopathology. In this study, we investigated the anti-ACD and anti-psoriasis effects of sea anemone Heteractis magnifica peptide HCRG21, a blocker of the TRPV1 channel, in 2,4-dinitrofluorobenzene (DNFB)- and imiquimod (IMQ)-induced mouse models, respectively. We found that topical application of 0.005–0.1% HCRG21 gels normalized hematological and immunological blood parameters in mice, significantly reduced the severity of ACD- and psoriasiform-like skin lesions, and increased the rate of tissue repair. The use of 0.005 and 0.05% HCRG21 gels decreased the production of IL-23-A and macrophage-derived chemokine (MDC) proteins in blood plasma, reduced the expression of Tnf, Il1β, Il6, Il23a, and Il17a genes, but increased the levels of the Il10 gene in scabs and/or blood of IMQ-treated mice. On the other hand, topical application of 0.05 and 0.1% HCRG21 reduced the expression of Il6 and Il23a in the DNFB-treated mice’s blood and it had no significant effects on TNF-α and IL-1β production. Thus, HCRG21 has the potential to be a treatment for psoriasis and dermatitis due to its potent anti-inflammatory properties. This effect is achieved by reducing pro-inflammatory cytokines associated with TRPV1 and normalizing immune cell levels in the bloodstream. This, in turn, leads to a decrease in clinical symptoms and an improvement in skin healing. Full article

Background: Psoriasis, an inflammatory skin disorder, involves pyroptosis—a pro-inflammatory cell death process. However, cell-specific pyroptosis dynamics and immune microenvironment interactions remain unclear. Objective: To investigate cell-type-specific pyroptosis patterns in psoriasis and their immunoregulatory mechanisms. Methods: We integrated 21 transcriptomic datasets (from 2007 to 2020) obtained from the GEO database and two single-cell RNA sequencing datasets to quantify pyroptotic activity using Gene Set Variation Analysis and AUCell algorithms. Immune cell infiltration profiles were evaluated via CIBERSORT, while cell-cell communication networks were analyzed by CellChat. In vitro and in vivo experiments were performed to validate key findings. Results: Our analysis revealed that psoriasis patients exhibited significantly elevated levels of pyroptosis compared to healthy controls, with pyroptotic activity reflecting treatment responses. Notably, monocyte-derived macrophages (MDMs) in psoriatic lesions displayed markedly heightened pyroptotic activity. In vitro experiments confirmed that MDMs derived from psoriasis patients overexpressed pyroptosis-related molecules (Caspase 1 and Caspase 4) as well as pro-inflammatory cytokines (TNFα, IL6, IL1β) when compared to healthy controls. Furthermore, these cells showed increased expression of CXCL16, which might potentially activate Th17 cells through CXCR6 signaling, thereby driving skin inflammation. Inhibition of monocyte migration in an imiquimod-induced psoriasiform dermatitis model significantly alleviated skin inflammation and reduced the proportion of M1 macrophages and Th17 cells in lesional skin. Conclusions: This study revealed that MDMs in psoriatic lesions exhibited a hyperactive pyroptotic state, which contributed to disease progression through CXCL16-mediated remodeling of the immune microenvironment. These findings highlight pyroptosis as a potential therapeutic target for psoriasis. Full article

Psoriasiform dermatitis refers to a spectrum of inflammatory skin disorders that resemble psoriasis both clinically and histologically. These conditions can occur idiopathically or as paradoxical reactions to biologic or targeted therapies, particularly in patients with atopic or autoimmune backgrounds. Histologic features often include acanthosis, parakeratosis, and lymphocytic infiltrates, but without the full molecular signature of classical psoriasis. This review provides an overview of psoriasiform dermatitis with a focus on its clinical presentation, differential diagnosis, and the immune pathways involved. Drug-induced forms, especially those triggered by anti-TNF agents, IL-4/IL-13 blockers, and JAK inhibitors, are highlighted due to their growing clinical relevance. We also summarize the main topical and systemic treatments, including corticosteroids, calcineurin inhibitors, PDE4 inhibitors, and JAK-STAT- or IL-23-targeted therapies. A better understanding of psoriasiform dermatitis is crucial to improve diagnosis and to guide treatment, especially in complex or refractory cases. Full article

Psoriasis pathogenesis involves dysregulated immune responses, yet the role of protein prenylation (particularly PGGT1B-mediated geranylgeranylation) in macrophage-driven inflammation remains poorly understood. This study aims to explore the role and molecular mechanism of protein geranylgeranyltransferase type I subunit beta (PGGT1B) in the development of psoriasis. Myeloid cell-specific PGGT1B gene knockout mice were generated, and a mouse psoriasis model was established with imiquimod to study the role and mechanism of PGGT1B gene downregulation-induced macrophage activation in the pathogenesis of psoriasis. Bone marrow-derived macrophages (BMDMs) from wild-type and PGGT1B knockout mice were cultured and stimulated with resiquimod (R848) to simulate the immune microenvironment of psoriasis. In addition, the differentially expressed genes induced by PGGT1B knockout were analyzed using RNA-seq, and bioinformatics analysis was carried out to study the possible biological process of PGGT1B regulation. Finally, PMA-THP-1 was co-cultured with HaCaT cells to study the effect of PGGT1B deletion in macrophages on the proliferation and differentiation of keratinocytes. Bone marrow PGGT1B deficiency aggravated the psoriasis-like lesions induced by imiquimod in mice. In BMDMs with PGGT1B deficiency, the NF-κB signaling pathway was over-activated by R848, and the expressions of proinflammatory cytokines IL-1β, IL-6, and TNF-α were significantly increased. Activation of cell division cycle 42 (CDC42) may mediate the activation of the NF-κB pathway in PGGT1B-deficient BMDMs. PGGT1B deletion can promote the proliferation and inhibit the differentiation of HaCaT cells. Reduced PGGT1B levels can increase the expression of CDC42, which further activates NLRP3 inflammation in macrophages through NF-κB signaling, further aggravating the inflammatory state of psoriasis. Psoriasis-like lesions induced by IMQ are aggravated when PGGT1B expression is reduced in mouse bone marrow cells. A possible mechanism for this is that PGGT1B-deficient macrophages migrate to the epidermis more easily during psoriasis, which leads to the activation of Cdc42, NF-κB signaling, and NLRP3 inflammatory corpuscles. Full article

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by epidermal barrier dysfunction and immune dysregulation, with interleukin (IL)-4, IL-13, and IL-31 recognized as key mediators. Prurigo nodularis (PN) is another chronic inflammatory disorder driven by T helper type 2-mediated inflammation and neural dysregulation, leading to severe pruritus. Nemolizumab, a humanized monoclonal antibody targeting IL-31 receptor A, has been approved for use in the treatment of AD and PN. Clinical trials have demonstrated significant reductions in pruritus and cutaneous symptoms associated with its use. In clinical practice, acute eczema and edematous erythema frequently occur, occasionally necessitating the discontinuation of treatment. Despite these observations, no comprehensive review has examined nemolizumab-associated cutaneous adverse events. This review aimed to examine various cutaneous reactions associated with nemolizumab therapy, including psoriasiform eruptions, AD exacerbation, bullous pemphigoid, drug-induced eruptions, and fungal infections. Potential mechanisms underlying these reactions include T-cell activation due to drug sensitization, immune responses triggered by nemolizumab acting as a hapten, and a relative increase in IL-4 and IL-13 levels following IL-31 inhibition. However, the precise pathophysiological mechanism and risk factors remain unclear, and standardized clinical management guidelines are lacking. Further accumulation of clinical data and immunological research are essential for developing evidence-based strategies to manage these adverse events, ensuring treatment continuity and optimizing patient outcomes. Full article

Cytotoxic-T-lymphocyte-antigen-4 (CTLA-4), a member of the immunoglobulin superfamily, is an essential negative regulator of immune responses that is constitutively expressed on both regulatory (Treg) and activated T cells. To date, heterozygous germline variants in CTLA4, leading to haploinsufficiency, have been associated with several immunological disorders, including hypogammaglobulinemia, multi-organ autoimmunity, lymphoproliferative disorders, and enlarged lymphoid organs. Indeed, CTLA4 carriers display highly heterogeneous clinical manifestations with a phenotypic spectrum ranging from asymptomatic carrier status to fatal autoimmunity. Here, we describe a family with autoimmune phenotypes (Hashimoto thyroiditis, psoriasiform dermatitis, celiac disease/inflammatory bowel disease, and rheumatoid arthritis), segregating across three different generations due to a recurrent missense variant [c.436G>A, p.(Gly146Arg)] in the CTLA4 gene. Interestingly, the proband showed prominent neurological manifestations, including seizures, hydrocephalus, and demyelination, which are less frequently reported in individuals with pathogenic variants in CTLA4. A detailed literature review of neurologic features that have been reported so far in CTLA4 carriers is also provided. Full article

Introduction: Psoriasis (PSO) and atopic dermatitis (AD) have traditionally been considered distinct diseases, respectively, mediated by T-helper 1 (Th1) and the T-helper 2 (Th2) immune pathway. In recent years, there has been a growing body of evidence highlighting an overlap between the two conditions, such as Asian AD, pediatric PSO, or “psoriasis dermatitis/PSOREMA”. Moreover, psoriasis dermatitis can be induced by therapeutic interventions. For instance, anti-IL-4/IL-13 monoclonal antibodies, commonly used to treat AD, can induce psoriasiform reactions by inhibiting the Th2 pathway, thereby unmasking Th1/Th17-driven PSO. Conversely, anti-TNFα and anti-IL-17 therapies, effective for PSO, may induce eczematous reactions promoting a switch toward Th2-driven inflammation. Janus Kinase Inhibitors (JAK-i) and IL-23 antagonists may represent valid therapeutic options for managing psoriasis dermatitis. JAK-i exert broader immunomodulatory effects, inhibiting both Th1 and Th2 pathways; however, they require careful monitoring due to potential adverse events. In contrast, IL-23 antagonists specifically suppress the IL-23/IL-17 axis inhibiting the p19 subunit of IL-23 and could represent a safer option for patients with psoriasis dermatitis. Materials and Methods/Results: We present a series of five cases of psoriasis dermatitis, including both patients who had the condition from the onset and those who developed it during treatment, with tailored therapeutic strategies based on individual patient profiles, comorbidities, and the specific characteristics of their overlapping disease presentation. Conclusion: JAK-i and IL-23 antagonists are both valid therapeutic options for managing psoriasis dermatitis, but with different immunomodulatory effects and safety profiles. Future research should focus on a better understanding of the immune pathway and identifying specific biomarkers of psoriasis dermatitis, to optimize therapeutic strategies. Full article

Immunotherapy, particularly that based on blocking checkpoint proteins in many tumors, including melanoma, Merkel cell carcinoma, non-small cell lung cancer (NSCLC), triple-negative breast (TNB cancer), renal cancer, and gastrointestinal and endometrial neoplasms, is a therapeutic alternative to chemotherapy. Immune checkpoint inhibitor (ICI)-based therapies have the potential to target different pathways leading to the destruction of cancer cells. Although ICIs are an effective treatment strategy for patients with highly immune-infiltrated cancers, the development of different adverse effects including cutaneous adverse effects during and after the treatment with ICIs is common. ICI-associated cutaneous adverse effects include mostly inflammatory and bullous dermatoses, as well as severe cutaneous side reactions such as rash or inflammatory dermatitis encompassing erythema multiforme; lichenoid, eczematous, psoriasiform, and morbilliform lesions; and palmoplantar erythrodysesthesia. The development of immunotherapy-related adverse effects is a consequence of ICIs’ unique molecular action that is mainly mediated by the activation of cytotoxic CD4⁺/CD8⁺ T cells. ICI-associated cutaneous disorders are the most prevalent effects induced in response to anti-programmed cell death 1 (PD-1), anti-cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and anti-programmed cell death ligand 1 (PD-L1) agents. Herein, we will elucidate the mechanisms regulating the occurrence of cutaneous adverse effects following treatment with ICIs. Full article

Psoriasis is a systemic autoimmune/autoinflammatory disease that can be well studied in established mouse models. Skin-resident macrophages are classified into epidermal Langerhans cells and dermal macrophages and are involved in innate immunity, orchestration of adaptive immunity, and maintenance of tissue homeostasis due to their ability to constantly shift their phenotype and adapt to the current microenvironment. Consequently, both macrophage populations play dual roles in psoriasis. In some circumstances, pro-inflammatory activated macrophages and Langerhans cells trigger psoriatic inflammation, while in other cases their anti-inflammatory stimulation results in amelioration of the disease. These features make macrophages interesting candidates for modern therapeutic strategies. Owing to the significant progress in knowledge, our review article summarizes current achievements and indicates future research directions to better understand the function of macrophages in psoriasis. Full article

Background: New oncologic therapies, including immune checkpoint inhibitors (ICIs), have revolutionized the survival and prognosis of cancer patients. However, these therapies are often complicated by immune-related adverse effects (irAEs) that may impact quality of life and potentially limit their use. Among these adverse events are psoriasis and psoriatic arthritis that may develop de novo or flare under treatment with ICIs. Given the exceptional immune status of patients receiving ICIs, managing these conditions without interfering with the effect of the oncologic treatment may prove very challenging. Aim: To review the literature data on ICI-induced psoriasis exacerbation or development, to present our own experience, and to discuss the pathogenic mechanisms underlying this association and the optimal therapeutic approach for these patients. Case Reports: We report three cases of ICI-induced de novo psoriasis and two cases of ICI-induced psoriasis exacerbation that required systemic treatment. Oral acitretin treatment successfully controlled psoriasis lesions in three cases and allowed for the continuation of immunotherapy. Literature Review: We performed a medical literature search across several databases (PubMed, Medline, Google Scholar) using the search terms “immune checkpoint inhibitor-induced psoriasis/psoriasiform dermatitis/psoriasis arthritis”. We identified and revised 80 relevant publications that reported 1102 patients with psoriasis and/or psoriasis arthritis induced or exacerbated by ICIs. We assessed the type of cancer, the therapeutic agent involved, the clinical form of psoriasis, the presence or absence of psoriatic arthritis, the personal and family history of psoriasis, the age, the gender, the time until onset or exacerbation of skin lesions, the specific treatment recommended, the need for ICI discontinuation, and the patient’s outcome. Conclusions: As ICIs represent a fairly novel therapy, the association with several adverse effects is only now unraveling. Psoriasis exacerbation or onset following the initiation of immunotherapy is one such example, as more and more reports and case series are being published. Awareness of the relationship between psoriasis and treatment with ICIs, prompt recognition, and initiation of adequate skin-directed therapies are essential for the avoidance of skin lesions worsening, the need for systemic treatments that may interfere with ICIs’ effects, or the discontinuation of the latter. In the absence of generally accepted guidelines, it is advisable to treat patients with severe, widespread psoriasis with drugs that do not impair the effects of immunotherapy and thus do not alter the patient’s prognosis. Full article

The status of parsley as a well-known folk medicine noted for its nutritional and medicinal properties prompted the exploration of its potential as a functional food and natural remedy. The paper aims to investigate the potential of parsley to enhance muscle function and alleviate psoriasiform dermatitis, eventually establishing it as a natural, well-tolerated alternative with specific benefits for both muscles and skin. This study examines the tolerability of parsley in a cohort of 937 participants by assessing immunoglobulin G (IgG) reactions. The findings reveal high tolerability, as 96.26% of participants experienced no adverse effects. Among the 902 individuals lacking hypersensitivity, 37.02% reported muscle cramps, with a notable 15.02% reduction observed in the subgroup consuming parsley juice. In the subset of 32 subjects with dermatitis, the application of parsley extract ointment led to a significant decrease in dermatological parameters (redness, thickness, scaling). While the control group exhibited improvements, statistical significance was not observed. Notably, four categories of affected area reduction were identified, with scaling demonstrating the most pronounced impact. The results propose that parsley holds promise for favorable tolerability, contributing to the alleviation of muscle cramps and presenting an effective alternative in dermatitis treatment. Nonetheless, sustained validation through long-term studies is imperative to substantiate these preliminary findings. Full article