Interleukin-17A and Keratinocytes in Psoriasis

Integrating transcriptomics and network pharmacology to reveal the effect and mechanism of Bai-Jie-Jing-Xie ointment on improving skin inflammation of psoriasis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a global chronic, immune-mediated, inflammatory skin disease. Bai-Jie-Jing-Xie (BJJX) ointment has been widely used in the clinic practice for its notable efficacy and is an empirical prescription for psoriasis treatment in hospitals. Nevertheless, its precise mechanism of action on psoriasis remains unclear.

AIM OF THE STUDY

To study the mechanism of action of the hospital empirical prescription BJJX in the treatment of psoriasis.

MATERIAL AND METHODS

Imiquimod (IMQ) was used to induce the psoriasis model in BALB/c mice and UPLC-MS/MS analysis was used for quality control. Subsequently, a combination of network pharmacology (NP) and Transcriptomic (RNA-Seq) methodology was used to assess the potential targets and mechanisms of action of BJJX on psoriasis. Finally, further validation was performed using flow cytometry, RT-qPCR, and western blotting.

RESULTS

BJJX significantly ameliorated IMQ-induced skin damage in psoriatic mice, reduced keratinocyte proliferation, and inhibited the levels of inflammatory factors (IL-23, IL-22, IL-17A, IL-6, IL-1β, and IL-8). NP predicts that BJJX may exert its therapeutic effects on psoriasis by modulating the IL-17 signaling pathway and Th17 cell differentiation. RNA-Seq analysis showed that BJJX regulated the expression of IL-17 pathway-related genes. Further experimental results demonstrated that BJJX treatment significantly reduced the mRNA expression of inflammatory factors CXCL2, CXCL3, MMP13, IL-1β, IL-23, IL-22, and IL-17A, as well as the proportion of Th17 cells. In addition, BJJX significantly inhibited the protein expression of JAK2 and STAT3.

CONCLUSIONS

BJJX attenuated IMQ-induced skin lesions in psoriasis mice by decreasing the expression of cytokines and chemokines mediated by the Th17/IL-17 axis. This study revealed, for the first time, the mechanism used by BJJX to treat psoriasis, providing a new paradigm for its pharmacological role in the clinical treatment of psoriasis.

The crosstalk of monocyte-neutrophil in hair follicles regulates neutrophil transepidermal migration in contact dermatitis

The excessive accumulation of neutrophils within the epidermis is a significant hallmark of cutaneous diseases; however, the mechanisms governing neutrophil transepidermal migration (NTEM) remain inadequately understood. In this study, we develop trichromatic-fluorescence-labeled chimeric mice by utilizing Cx3cr1GFP/+Lyz2RFP/+ mice as bone marrow donors and Krt14YFP/+ mice as recipients. This approach enables us to visualize the process of NTEM and the crosstalk between neutrophils and monocytes in a murine model of irritant contact dermatitis (ICD). Intravital imaging reveals a preferential transmigration of neutrophils through hair follicle (HF), where dermal neutrophils exhibit limited mobility and interact with dermal monocytes. Notably, 18 h following hapten exposure, dermal neutrophils continuously migrate toward HF regions and form clusters within 3 h. Importantly, MMP-9 is identified as essential for the NTEM process; the depletion of dermal monocytes results in a significant reduction of MMP-9 expression in the skin and inhibits the NTEM process in ICD. Mechanistically, dermal monocytes are found to be a crucial source of the cytokines TNF-α and CXCL2, which promote the upregulation of MMP-9 in neutrophils. Therefore, our results highlight HF regions as crucial gateways for dermal monocyte-modulated NTEM and provide visual insights into the crosstalk between neutrophils and monocytes in inflammatory skin disorders.

Ex vivo cell-based assay for assessment of response to TNF inhibitors in patients with rheumatic diseases

OBJECTIVE

There are five TNF inhibitors (TNFis), whose structure and signalling differ. An individual patient with a rheumatic disease may respond to one TNFi but not to another. In addition, 30-40% of patients with rheumatic diseases may respond inadequately to TNFis. The downstream signalling of the various TNFis may determine their clinical efficacy. Several reports have shown that the different TNFis exhibited differential effects on Th17 cells. We analysed the effects of the various TNFis on IL-17A expression in peripheral blood mononuclear cells (PBMCs) of patients with rheumatic diseases, in order to evaluate the possibility of predicting responses in an ex vivo setting.

METHODS

PBMCs were co-cultured with the various TNFis or medium (control), and IL-17A mRNA levels were analysed by quantitative PCR. IL-17A expression levels in response to four TNFis (not including certolizumab pegol) were compared with that of the control. The IL-17A expression level as determined by the assay was correlated with the clinical response. The assay sensitivity and specificity for distinguishing responders from non-responders was calculated by receiver-operating characteristic (ROC) analysis.

RESULTS

The results of the assay for a retrospective cohort of patients with rheumatic diseases (n = 82) correlated with their therapeutic responses to the various TNFis with 89.5% accuracy. Our results indicated that the assay predicted the responses of a prospective cohort (n = 54) to specific TNFis with 79% accuracy.

CONCLUSION

This functional assay could assist in predicting the odds for response to TNFi therapy, indicating whether a given patient is likely to respond to a specific TNFi.

Combination therapy of systemic and local metformin improves imiquimod-induced psoriasis-like lesions with type 2 diabetes: the role of AMPK/KGF/STAT3 axis

CONTEXT

Insulin resistance and a disturbed lipid profile are common associations with type 2 diabetes mellitus (T2DM) and different skin diseases, particularly psoriasis (PsO).

OBJECTIVES

We investigated potential therapeutic mechanisms of metformin in a murine animal model of psoriasiform lesions in T2DM.

MATERIALS AND METHODS

Forty-two rats were randomly divided into control, PsO, and type II DM (T2DM) groups. After confirmation of DM, the type II diabetic rats were allocated into T2DM+ PsO, T2DM+ PsO+ systemic metformin (S. met), T2DM+ PsO+ topical metformin (T. met)), and T2DM+ PsO + combined metformin (C. met). PsO was induced by topical imiquimod.

RESULTS

Systemic administration of the cornerstone antidiabetic drug, metformin, was able to improve insulin resistance and lipid profile. At molecular levels, both topical and systemic metformin significantly increased AMP-activated protein kinase (AMPK), and lowered keratinocyte growth factor (KGF) / "Signal transducer and activator of transcription" (STAT)3 protein levels, and the IL-17RA and IL-17RC gene expression.

CONCLUSION

Although its glucose-controlling effect was not optimum, T.met gel served anti-psoriatic and anti-inflammatory effects.

The preclinical discovery and development of secukinumab for the treatment of moderate-to-severe hidradenitis suppurativa

INTRODUCTION

Hidradenitis suppurativa (HS) is a chronic skin condition with a significant impact on patient quality of life, highlighting the need for innovative therapeutic approaches. HS is characterized by its chronicity; it presents in the form of painful nodules, abscesses, and sinus tracts or fistulas, typically localized in intertriginous areas, emerging in early adulthood and in predominantly the female population.

AREAS COVERED

In this review, the authors discuss the preclinical discovery and development of secukinumab for HS, highlighting target identification, validation, and compound selection. Methodologies such as high-content screening, chemoinformatics, and animal models that validate the IL-17 pathway's role in HS are explored. The transition from preclinical to clinical development, including pharmacokinetics (PK), pharmacodynamics (PD), and ADME-Tox studies, is elaborated. The literature search was conducted using PubMed, Web of Science, Scopus, UpToDate, Cochrane Library, Embase, and Google Scholar, covering relevant studies published up to December 2024.

EXPERT OPINION

The integration of secukinumab into HS treatment highlights the critical role of targeting the IL-17A pathway. Although efficacious and safe in trials, understanding secukinumab's long-term effects and optimal treatment placement remains challenging. Future research should prioritize the development of tailored therapeutic strategies that align with individual disease phenotypes and immune profiles to enhance treatment outcomes in HS management.

Topical delivery of pterostilbene nanoemulgel ameliorates imiquimod-induced psoriasis-like skin inflammation in mice

AIM

This study evaluates the therapeutic potential of Pterostilbene (PTN), a natural stilbenoid, in an imiquimod (IMQ)-induced psoriasis model. Due to PTN's poor solubility and bioavailability, a pterostilbene nano-emulsion gel (PTN-NEG) formulation (0.1% and 0.2% w/w) was developed to enhance its therapeutic efficacy.

METHODS

Psoriasis was induced in C57BL/6J mice by applying IMQ (62.5 mg/day) on a 5 cm2 shaved dorsal skin area for 7 days. PTN-NEG was topically applied, and its effects on oxidative stress, inflammatory cytokines (IL-17, TNF-α, IL-22), NF-κB pathway activation, and keratinocyte proliferation markers (Ki-67, Bcl-xL) were assessed. The expression of dual-specificity phosphatase-1 (DUSP-1) and its role in modulating mitogen-activated protein kinase (MAPK) signaling were evaluated. Additionally, DNA methyltransferase-1 (DNMT-1) inhibition was examined to explore PTN's epigenetic impact.

RESULTS

PTN-NEG restored antioxidant balance, reduced pro-inflammatory cytokines, inhibited NF-κB activation, and suppressed keratinocyte proliferation. It unregulated DUSP-1, modulating MAPK signaling and preventing psoriasis progression. PTN-NEG also improved epidermal structure, reduced hyperplasia, and prevented splenomegaly. Notably, PTN inhibited DNMT-1, suggesting a novel epigenetic mechanism for psoriasis.

CONCLUSION

To our knowledge, this study is the first to demonstrate that PTN-NEG mitigates psoriasis through anti-inflammatory, antioxidant, and epigenetic regulatory mechanisms, highlighting its therapeutic potential in psoriasis management.

Efficacy of IDOR-1117-2520, a novel, orally available CCR6 antagonist in preclinical models of skin dermatitis

BACKGROUND AND PURPOSE

The chemokine receptor CCR6 guides pathogenic T17 cells, implicated in autoimmune diseases including psoriasis, to sites of inflammation via the chemokine CCL20. Therefor, pharmacological inhibition of CCR6+ immune cell migration provides a novel therapeutic approach. Translatability of such an intervention has not yet been assessed in detail. We evaluated the translatability of the Aldara® mouse model induced skin inflammation to psoriasis, with particular focus on immune cell trafficking and assessed the efficacy of IDOR-1117-2520, a highly selective, potent and orally available CCR6 small inhibitor.

EXPERIMENTAL APPROACH

Effects of IDOR-1117-2520 were investigated in the Aldara® and IL23 mouse models of skin inflammation using flow cytometry, RNA sequencing and transcriptome-based cell type deconvolution approaches to characterise immune cell migration patterns. These results were compared to human psoriasis transcriptomics data.

KEY RESULTS

IDOR-1117-2520 dose dependently reduced infiltration of CCR6+ immune cells into inflamed skin, and was equally efficacious as IL-17 and IL-23 inhibition in models of skin inflammation. Pathway analysis showed molecular similarities in the immune response between human psoriasis and the Aldara® mouse model. IL-17/IL-23 pathway genes were expressed in both human psoriasis and the mouse model. CCR6 inhibition modulated multiple pathways associated with inflammation beyond the proximal IL-17/IL-23 pathway. A chemokine-chemokine receptor interaction map implicated CCL20-CCR6 as the dominant axis in recruiting pathogenic T17 cells in both the model and in human psoriasis.

CONCLUSION AND IMPLICATIONS

IDOR-1117-2520 could provide a promising novel targeted approach to treating psoriasis and, potentially, other autoimmune diseases involving the CCR6/CCL20 axis and the IL-17/IL-23 pathway. IDOR-1117-2520 is currently being evaluated in a clinical phase 1 trial (ISRCTN28892128).

Unveiling the role of resident memory T cells in psoriasis

Psoriasis is a chronic inflammatory skin disease characterized by periods of remission and relapse. In this pathology, keratinocytes, dendritic cells, and different subpopulations of T cells are critical to developing psoriatic lesions. Although current treatments can reduce symptoms, they reappear in previously injured areas months after stopping treatment. Evidence has pointed out that besides T-helper 17 cells, other T-cell subsets may be involved in relapses. This review focuses on the leading evidence linking resident memory T cells and P2X7 receptor to psoriasis' pathogenesis and their role in this pathology. Finally, we discuss some of the most widely used experimental murine models and novel strategies to investigate further the role of resident memory T cells in psoriasis.

Small molecule interleukin (IL) 17A/A antagonists and antibodies blocking both IL17A/A and IL17A/F demonstrate equivalent degrees of efficacy in preclinical models of skin and joint inflammation

T-helper 17 (Th17) cells produce homodimeric IL17A/A and IL17F/F cytokines as well as the heterodimeric IL17A/F isoform, all having well known roles in defense against extracellular pathogens including fungal infection. Antibodies targeting IL17A (such as secukinumab and ixekizumab) have been approved to treat psoriasis, psoriatic arthritis, ankylosing spondylitis, and axial spondyloarthritis and are under further investigation as therapies in inflammatory disorders such as hidradenitis suppurativa and giant cell arteritis. Because many patients dislike injections with needles, orally bioavailable small molecule IL17 antagonists are desirable as next-generation drugs as long as they can replicate the degree of efficacy observed with anti-IL17A biologics. We recently described novel small molecules binding as 2 copies to the IL17A/A homodimer with only weak effects on the IL17A/F heterodimer. Because approved antibodies binding IL17A neutralize both IL17A/A and IL17A/F, we assessed whether targeting IL17A/A would be sufficient to bring efficacy comparable to IL17A biologics. In comparison to IL17A/F and IL17F/F, we found that the IL17A/A homodimer is the strongest initiator of signaling and that comparable IL17A/A to IL17A/F ratios are expressed in Th17 cells and in human psoriatic skin tissue. Furthermore, our IL17A/A-specific small molecules block the effects of Th17 cell supernatants on keratinocytes to similar maximal responses as anti-IL17A. Our IL17A/A-selective antagonists deliver comparable efficacy to anti-IL17A biologics in several rodent inflammatory models of psoriasiform dermatitis and arthritis. These results support neutralizing IL17A/A with oral small molecule antagonists is an attractive approach to provide differentiated, next-generation therapies for inflammatory disorders. SIGNIFICANCE STATEMENT: This study found that orally active small molecule antagonists of the proinflammatory cytokine IL17A that preferentially bind the IL17A/A form produced equivalent efficacy to monoclonal antibodies that can neutralize both IL17A/A and IL17A/F. This indicates that the IL17A/A homodimer is the dominant isoform driving inflammation in diseases such as psoriasis and that oral inhibitors targeting IL17A/A may be useful next-generation IL17 therapeutics.

Phytotherapeutic Analysis of Chloroform-Based Fractions of Alstonia scholaris and Wrightia tinctoria Extracts Reveals Potent Anti-Psoriatic Activity: An In Vitro and In Vivo Study

Background/Objectives: Psoriasis, a prevalent dermatological disorder, poses therapeutic challenges due to limited effective treatments or adverse side-effects. Traditional medicinal plants like Alstonia scholaris and Wrightia tinctoria, historically used in Ayurvedic and Siddha practices, show potential in treating inflammatory skin diseases. This study aims to explore their in vitro and in vivo anti-psoriatic properties to develop safer and more effective therapies. Methods: Chloroform:methanol fractions from ethanol extracts of Alstonia scholaris and Wrightia tinctoria were evaluated for anti-psoriatic activity. In vitro assays using HaCaT cells assessed cell viability, apoptosis, and inflammatory markers. In vivo studies utilized an IMQ-induced psoriasis mouse model, evaluating skin lesions, histopathology, and cytokine profiles. Results: Chloroform fractions significantly reduced HaCaT cell viability and induced apoptosis. They also dose-dependently downregulated IL-8 and RANTES levels. In vivo, these fractions reduced skin inflammation, edema, and psoriasis scores. Histopathological analysis showed decreased epidermal thickness and dermal inflammation. Key psoriasis biomarkers IL-17 and IL-23 were significantly reduced. Conclusions: Chloroform:methanol fractions from Alstonia scholaris and Wrightia tinctoria demonstrated potent anti-psoriatic effects in vitro and in vivo. These findings support their potential as novel phytotherapeutic agents for managing psoriasis, offering promise for further development and clinical application.

Exploring the dynamic responses of group 3 innate lymphoid cells at different times in response to LPS challenge

Group 3 innate lymphoid cells (ILC3s) have clear roles in regulating mucosal immunity and tissue homeostasis in the intestine, though the immunological functions in lungs remain unclear. This study aimed to demonstrate the dynamic responses of ILC3s to acute inflammation upon LPS challenge. Microarray data and single-cell RNA sequencing (scRNA-seq) data obtained from the GEO database were combined to analyze the function of ILC3 subset, confirmed by flow cytometry assay and qRT-PCR. The gene enrichment analysis of intersected genes identified between microarray data in bacterial pneumonia and single-cell RNA sequencing of intestinal ILC3s were closely related to TNF-alpha effects on cytokine activity, cell motility and apoptosis pathway, indicating the possibility of intestinal ILC3s migration to the lung. Furthermore, the cellular landscapes of ILC3s in lung and intestine at different times after pulmonary infection exhibited varied ILC3 statuses. ILC3s in lung expanded a lot at 48 h while intestinal ILC3s decreased at 72 h response to LPS challenge, with higher expression of marked genes related to TNF-alpha effects on cytokine activity, cell motility and apoptosis pathway. The main findings in our study may serve as valuable resources for understanding the roles that ILC3s play upon LPS challenge, which may offer opportunities for translating ILC3s as therapeutic targets to regulate LPS-induced pulmonary inflammation.

Anti-Inflammatory Effects of Curcumin-Based Nanoparticles Containing α-Linolenic Acid in a Model of Psoriasis In Vitro

Background/Objectives. Psoriasis is a common chronic skin inflammatory disorder pathogenetically associated with genetic, environmental, and immunological factors. The hallmarks of psoriatic lesions include sustained inflammation related to alterations in the innate and adaptive immune response, uncontrolled keratinocyte proliferation, differentiation, and death, as well as dysregulated crosstalk between immune cells and keratinocytes. In search of novel therapeutic strategies based on the use of natural products and dietary components to combine to the available conventional and innovative therapeutics, we explored the anti-inflammatory, antioxidant, and immunomodulatory activities of Curcumin (CU)-based solid lipid nanoparticles (SLNs) carrying the omega-3 fatty acid linolenic acid (LNA) in an in vitro model of psoriasis that had been previously constructed and characterized by us. Methods. This in vitro model consists of differentiated in vitro THP-1 macrophages (Mφs) and NCTC-2544 keratinocytes exposed or not to conditioned medium (CM) from Mφs treated with the Toll-like receptor-7 ligand imiquimod (IMQ). Results. In Mφs, the treatment with CU-LNA-SLNs inhibited the IMQ-induced expression of proinflammatory cytokines (IL-23, IL-8, IL-6: 43%, 26.5% and 73.7% inhibition, respectively, vs IMQ-treated Mφs), as well as the hyperproliferative response (12.8% inhibition vs IMQ-treated Mφs) and the increase in cell death observed in keratinocytes treated with Mφ-derived CM (64.7% inhibition). Moreover, in the same conditions, CU-LNA-SLNs reverted to control levels of the increased keratinocyte expression of two markers of ferroptosis, a form of death recently involved in the pathogenesis of psoriasis (TFRC and MDA: 13.4% and 56.1% inhibition, respectively). Conclusions. These results suggest that CU-LNA-SLNs could inhibit psoriatic inflammation, as well as the hyperproliferation and death of keratinocytes in psoriatic lesions, and could be considered as a new possible therapeutic strategy for psoriasis to be further evaluated for the topic treatment of psoriatic skin in vivo.

TRPV1+ neurons promote cutaneous immunity against Schistosoma mansoni

Immunity against skin-invasive pathogens requires mechanisms that rapidly detect, repel or immobilize the infectious agent. While bacteria often cause painful cutaneous reactions, host skin invasion by the human parasitic helminth Schistosoma mansoni often goes unnoticed. This study investigated the role of pain-sensing skin afferents that express the ion channel Transient Receptor Potential Vanilloid 1 (TRPV1) in the detection and initiation of skin immunity against S. mansoni . Data show that mice infected with S. mansoni have reduced behavioral responses to painful stimuli and sensory neurons exposed from infected mice have significantly less calcium influx and neuropeptide release in response to the TRPV1 agonist capsaicin. Using both gain- and loss-of-function approaches, data show that TRPV1+ neurons are critical regulators of S. mansoni survival during migration from the skin into the pulmonary tract. Moreover, TRPV1+ neurons were both necessary and sufficient to promote proliferation and cytokine production from dermal γδ T cells as well as neutrophil and monocyte skin accumulation post-infection. These results suggest a model in which S. mansoni may have evolved to inhibit TRPV1+ neuron activation as a countermeasure that limits IL-17-mediated inflammation, facilitating systemic dissemination and chronic parasitism.

One sentence summary

The parasitic helminth Schistosoma mansoni averts IL-17-dependent protective immunity by suppressing skin-innervating TRPV1+ neurons.

Harnessing the Anti-Inflammatory Effects of Perinatal Tissue Derived Therapies for the Treatment of Inflammatory Skin Diseases: A Comprehensive Review

Dealing with chronic inflammatory skin conditions like atopic dermatitis and psoriasis can be extremely difficult. Current treatments, such as topical corticosteroids, often have limitations and side effects. However, researchers have discovered that the placenta's remarkable properties may provide a breakthrough in effectively addressing these skin conditions. The placenta comprises three essential tissues: decidua, placental membrane, and umbilical cord. Placental derivatives have shown significant potential in treating psoriasis by reducing inflammatory cytokines and inhibiting keratinocyte proliferation. In the case of atopic dermatitis, umbilical cord stem cells have demonstrated anti-inflammatory effects by targeting critical factors and promoting anti-inflammatory cytokines. The scope of benefits associated with placental derivatives transcends these specific applications. They also potentially address other inflammatory skin diseases, such as vitiligo, by stimulating melanin production. Moreover, these derivatives have been leveraged in the treatment of pemphigus and epidermolysis bullosa (EB), showcasing potential as a wound dressing that could eliminate the necessity for painful dressing changes in EB patients. In summary, the integration of placental derivatives stands to revolutionize our approach to inflammatory skin conditions owing to their distinct properties and the prospective benefits they offer. This comprehensive review delves into the current applications of placental derivatives in addressing inflammatory skin diseases, presenting a novel treatment approach.

Current therapeutic overview and future perspectives regarding the treatment of psoriasis

Psoriasis is a chronic inflammatory skin disease affecting millions of people worldwide, characterized by rapid proliferation of keratinocytes, immune cell infiltration, and systemic inflammation. Over time, treatment strategies have evolved significantly from traditional topical therapies and phototherapy to advanced systemic options such as biologics and, more recently, oral small molecule drugs. This review aims to provide an in-depth examination of current psoriasis therapies, with a focus on biologics, oral small molecules, and new and emerging treatments. Several classes of biologic therapies have received regulatory approval for psoriasis, including inhibitors of TNF-α, IL-12/23, IL-17, and IL-23. Biologics have transformed psoriasis care, offering improved disease management and quality of life for patients, with generally favorable safety profiles. However, challenges such as high cost, potential immunogenicity and complexity of administration have sparked interest in alternative treatment options. Oral small molecules, particularly Janus kinase (JAK) inhibitors, have gained attention for their efficacy and ease of use, being orally administered drugs. These drugs mark a shift in therapeutic paradigms by providing an oral option that precisely targets specific signaling pathways. In addition to existing therapies, this review also highlights emerging treatments that could shape the future of psoriasis care, including new small-molecule inhibitors. Early clinical trials suggest that these agents could improve treatment outcomes for psoriasis patients. Current research is increasingly focused on understanding disease recurrence, particularly the influence of tissue-resident memory T cells (TRMs). Avoiding the proliferation of these cells may be crucial in attenuating recurrence. In particular, interleukin-23 (IL-23), produced by CD301b+ cells, has been linked to stimulation of TRM cell proliferation in the skin. This finding highlights that IL-23 inhibitors and treatments targeting CD301b+ cells are promising strategies for maintaining remission and preventing relapse. In summary, the landscape of psoriasis treatments is advancing rapidly, with an increasing focus on personalized, patient-specific therapies. Research is expected to continue to refine and improve therapeutic approaches for this complex disease.

Macrophages dying from ferroptosis promote microglia-mediated inflammatory responses during spinal cord injury

The neurological deficits following traumatic spinal cord injury are associated with severe patient disability and economic consequences. Currently, an increasing number of studies are focusing on the importance of ferroptosis during acute organ injuries. However, the spatial and temporal distribution patterns of ferroptosis during SCI and the details of its role are largely unknown. In this study, in vivo experiments revealed that microglia are in close proximity to macrophages, the major cell type that undergoes ferroptosis following SCI. Furthermore, we found that ferroptotic macrophages aggravate SCI by inducing the proinflammatory properties of microglia. In vitro studies further revealed ferroptotic macrophages increased the expression of IL-1β, IL-6, and IL-23 in microglia. Mechanistically, due to the activation of the NF-κB signaling pathway, the expression of IL-1β and IL-6 was increased. In addition, we established that increased levels of oxidative phosphorylation cause mitochondrial reactive oxygen species generation and unfolded protein response activation and trigger an inflammatory response marked by an increase in IL-23 production. Our findings identified that targeting ferroptosis and IL-23 could be an effective strategy for promoting neurological recovery after SCI.

T cells promote distinct transcriptional programs of cutaneous inflammatory disease in keratinocytes and dermal fibroblasts

T cells and structural cells coordinate appropriate inflammatory responses and restoration of barrier integrity following insult. Dysfunctional T cells precipitate skin pathology occurring alongside altered structural cell frequencies and transcriptional states, but to what extent different T cells promote disease-associated changes remains unclear. We show that functionally diverse circulating and skin-resident CD4+CLA+ T cell populations promote distinct transcriptional outcomes in human keratinocytes and fibroblasts associated with inflamed or healthy tissue. We identify Th17 cell-induced genes in keratinocytes that are enriched in psoriasis patient skin and normalized by anti-IL-17 therapy. We also describe a CD103+ skin-resident T cell-induced transcriptional module enriched in healthy controls that is diminished during psoriasis and scleroderma and show that CD103+ T cell frequencies are altered during disease. Interrogating clinical data using immune-dependent transcriptional signatures defines the T cell subsets and genes distinguishing inflamed from healthy skin and allows investigation of heterogeneous patient responses to biologic therapy.

Limonin Exhibits Anti-Inflammatory Effects by Inhibiting mTORC1 and Mitochondrial Reactive Oxygen Species in Psoriatic-like Skin Inflammation

Psoriasis is a chronic inflammatory skin disorder characterized by abnormal immune responses and keratinocyte hyperproliferation. Limonin, a bioactive compound found in citrus fruits, has anti-inflammatory properties in various models; however, its effects on psoriasis are not fully understood. We investigated the therapeutic potential of limonin in a 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced psoriasis mouse model. Mice were treated with TPA to induce psoriasis-like skin lesions, followed by intraperitoneal administration of limonin (200 or 400 μg/mouse) for six days. The results showed that limonin improved psoriasis-related symptoms in a psoriasis-like mouse model by suppressing the mRNA expression of pro-inflammatory cytokines and inflammation-related antimicrobial peptides and regulating the expansion of myeloid cells and T cells. Specifically, limonin reduced glucose uptake and oxidative phosphorylation to shift the metabolic program in the inflamed skin cells of psoriasis-like mice. Limonin activates AMPK and proteins related to mTOR inhibition, thereby suppressing the mTOR signaling pathway. It also inhibits mitochondrial mass and mitochondrial ROS production, thereby preventing the development of dysfunctional mitochondria in inflamed skin cells. Overall, limonin modulates key immune responses and metabolic pathways related to inflammation and mitochondrial health in psoriasis. Therefore, it is a promising natural candidate for the treatment of psoriasis and various inflammatory skin diseases.

Psoriatic arthritis in psoriasis: optimizing the current screening system for psoriatic arthritis based on serum data from U.S. and Chinese populations

Background

Psoriatic arthritis (PSA) is an inflammatory joint disease associated with psoriasis (PSO) that can be easily missed. Existing PSA screening tools ignore objective serologic indicators. The aim of this study was to develop a disease screening model and the Psoriatic Arthritis Inflammation Index (PSAII) based on serologic data to enhance the efficiency of PSA screening.

Method

A total of 719 PSO and PSA patients from the National Health and Nutrition Examination Survey (NHANES) (as training set and test set) and 135 PSO and PSA patients who were seen at The First Affiliated Hospital of Zhejiang Chinese Medical University (as external validation set) were selected, 31 indicators for these patients were collected as potential input features for the model. Least Absolute Shrinkage and Selection Operator (LASSO) was used to identify PSA-related features. Five models of logistic regression (LR), random forest, k-nearest neighbor, gradient augmentation and neural network were developed in the training set using quintuple cross validation. And we developed PSAII based on the results of LASSO regression and weights of logistic model parameters. All performance metrics are derived on the test set and the external validation set.

Results

Five variables were selected to build models, including age, lymphocyte percentage, neutrophil count, eosinophilic count, and C-reactive protein. In all established models, the LR model performed the best, with an Area Under Curve (AUC) of 0.87 (95% confidence interval (CI): 0.83-0.90) on the test set; on the external validation set the AUC was 0.82 (95%CI: 0.74-0.90). The PSAII formula was PSAII = percentage of lymphocytes × C-reactive protein/(neutrophil count × eosinophilic count × 10). The AUC of PSAII in the test is 0.93 (95%CI: 0.88-0.97), and the cutoff value is 18. The AUC of the external validation set is 0.81 (95%CI: 0.72-0.89).

Conclusions

This study developed and validated five models to assist screening for PSA by analyzing serum data from NHANES and Chinese populations. The LR model demonstrated the best performance. We created PSAII for PSA screening. However, the high false positive rate of PSAII makes it necessary to combine it with other PSA screening tools when applied.

Daturataturin A Ameliorates Psoriasis by Regulating PPAR Pathway

Psoriasis is a kind of severe immune-mediated systemic skin disorder, becoming a worldwide public health concern. Daturataturin A (DTA), a withanolide compound, exerts excellent anti-inflammatory and anti-proliferative properties. The objective of this study is to elucidate the effect of DTA on psoriasis and its potential mechanism. We established psoriasis-like keratinocytes model by stimulating HaCaT cells with M5 cocktail cytokines including Interleukin (IL)-17A, IL-22, oncostatin M, IL-1α, and tumor necrosis factor-α (TNF-α), followed by intervention with DTA. The potential effects and mechanisms of DTA on psoriasis were evaluated in vitro. DTA was found to be able to inhibit hyperproliferation, promote apoptosis, decrease the release of pro-inflammatory cytokines, downregulate keratin expression, and improve lipid metabolism via regulating the peroxisome proliferator-activated receptor (PPAR) signaling pathway by M5 cocktail cytokines stimulation in HaCaT cells. DTA ameliorated lipid metabolism of psoriasis and exerted the potential anti-psoriasis effects by regulating PPAR pathway in vitro, suggesting that DTA may act as a new therapeutic agent for psoriasis.

Skin Stretching Techniques: A Review of Clinical Application in Wound Repair

Background

The repair of skin defect wounds is a long-term goal of clinical pursuit. Currently, free or pedicled skin flap transplantation is commonly used to repair skin defects. However, these methods may lead to complications such as flap necrosis, thrombosis, scarring, diminished sensation, and pigmentation in both the donor and recipient areas. Since its introduction in 1976, skin stretching techniques were widely used for minor skin and soft-tissue defects in the surgical field.

Methods

A narrative review was conducted to identify relevant articles about the skin stretching techniques for promoting wound healing. We searched the Web of Science and PubMed databases for all articles containing different combinations of "skin stretch techniques" and "wound repair," "skin defects," and "tissue expansion."

Results

Through the screening of 500 articles, 84 representative and persuasive articles were selected in this review. These studies collectively demonstrate the technique's effectiveness in reducing wound size, facilitating primary closure, and improving cosmetic outcomes. Reported complications were generally minor, including transient erythema and mild discomfort, with rare instances of skin necrosis.

Conclusions

Skin stretch techniques emerge as a promising approach for managing large-area wounds, offering the advantage of achieving primary healing without compromising surrounding healthy tissue. However, to optimize its clinical application, further research is warranted, particularly in addressing challenges related to precise stretching and infection management.

Investigation of paeonol in dermatological diseases: an animal study review

Cortex Moutan is the root bark of the buttercup plant Paeonia suffruticosa Andr, of Ranunculaceae family. It has been utilized in Chinese medicine for thousands of years to treat a multitude of diseases, and traditional Chinese documents allege that it has heat-clearing, antipyretic, anti-inflammatory and detoxicating properties. Paeonol is a bioactive substance extracted from Cortex Moutan, which is considered to be one of its most effective metabolites. Recent studies have illustrated that paeonol treatment can alleviate skin damage, relieve the inflammatory response in patients with numerous dermatological conditions, and inhibit anomalous proliferation of skin tissue. Accordingly, paeonol may serve as a potential therapeutic agent for a variety of skin conditions. This review summarizes the physicochemical properties and pharmacokinetics (PK) characteristics of paeonol, and mechanisms of operation in diverse skin diseases, including dermatitis, psoriasis, pruritus, photoaging, hyperpigmentation, and hyperplasticscar. Additionally, much of the evidence is based on animal experiments. Furthermore, it explores the prospects of enhancing paeonol's efficacy through extraction, synthesis, and formulation innovations, as well as strategies to overcome its limitations in dermatological therapy. This review aims to provide a more reliable theoretical basis for the clinical application of paeonol.

Constrained Pseudo-Time Ordering for Clinical Transcriptomics Data

Time series RNASeq studies can enable understanding of the dynamics of disease progression and treatment response in patients. They also provide information on biomarkers, activated and repressed pathways, and more. While useful, data from multiple patients is challenging to integrate due to the heterogeneity in treatment response among patients, and the small number of timepoints that are usually profiled. Due to the heterogeneity among patients, relying on the sampled time points to integrate data across individuals is challenging and does not lead to correct reconstruction of the response patterns. To address these challenges, we developed a new constrained based pseudo-time ordering method for analyzing transcriptomics data in clinical and response studies. Our method allows the assignment of samples to their correct placement on the response curve while respecting the individual patient order. We use polynomials to represent gene expression over the duration of the study and an EM algorithm to determine parameters and locations. Application to four treatment response datasets shows that our method improves on prior methods and leads to accurate orderings that provide new biological insight on the disease and response.

Spatial transcriptomics reveals organized and distinct immune activation in cutaneous granulomatous disorders

BACKGROUND

Noninfectious (inflammatory) cutaneous granulomatous disorders include cutaneous sarcoidosis (CS), granuloma annulare (GA), necrobiosis lipoidica (NL), and necrobiotic xanthogranuloma (NXG). These disorders share macrophage-predominant inflammation histologically, but the inflammatory architecture and the pattern of extracellular matrix alteration varies. The underlying molecular explanations for these differences remain unclear.

OBJECTIVE

We sought to understand spatial gene expression characteristics in these disorders.

METHODS

We performed spatial transcriptomics in cases of CS, GA, NL, and NXG to compare patterns of immune activation and other molecular features in a spatially resolved fashion.

RESULTS

CS is characterized by a polarized, spatially organized type 1-predominant response with classical macrophage activation. GA is characterized by a mixed but spatially organized pattern of type 1 and type 2 polarization with both classical and alternative macrophage activation. NL showed concomitant activation of type 1, type 2, and type 3 immunity with a mixed pattern of macrophage activation. Activation of type 1 immunity was shared among, CS, GA, and NL and included upregulation of IL-32. NXG showed upregulation of CXCR4-CXCL12/14 chemokine signaling and exaggerated alternative macrophage polarization. Histologic alteration of extracellular matrix correlated with hypoxia and glycolysis programs and type 2 immune activation.

CONCLUSIONS

Inflammatory cutaneous granulomatous disorders show distinct and spatially organized immune activation that correlate with hallmark histologic changes.

Identification of Key Genes Related to Immune-Lipid Metabolism in Skin Barrier Damage and Analysis of Immune Infiltration

Several physical and chemical factors regulate skin barrier function. Skin barrier dysfunction causes many inflammatory skin diseases, such as atopic dermatitis and psoriasis. Activation of the immune response may lead to damage to the epidermal barrier. Abnormal lipid metabolism is defined as abnormally high or low values of plasma lipid components such as plasma cholesterol and triglycerides. The mouse skin barrier damage model was used for RNA sequencing. Bioinformatics analysis and validation were performed. Differently expressed genes (DEGs) related to immune and lipid metabolism were screened by differentially expressed gene analysis, and the enriched biological processes and pathways of these genes were identified by GO-KEGG. The interactions between DEGs were confirmed by constructing a PPI network. GSEA, transcription factor regulatory network, and immune infiltration analyses were performed for the 10 genes. Expression validation was performed by public datasets. The expression of key genes in mouse skin tissue was detected by qPCR. The expression of differentially expressed immune cell markers in the skin was detected by immunofluorescence. Based on the trans epidermal water loss (TEWL) score, the expression of key genes was detected by qPCR before skin barrier injury, at 4h and 7d, and at recovery from injury. Il17a, Il6, Tnf, Itgam, and Cxcl1 were immune-related key genes. Pla2g2f, Ptgs2, Plb1, Pla2g3, and Pla2g2d were key genes for lipid metabolism. Database validation and experimental results revealed that the expression trends of these genes were consistent with our analyses. The research value of these genes has been demonstrated through mouse datasets and experimental validation, and future therapeutic approaches may be able to mitigate the disease by targeting these genes to modulate the function of the skin barrier.

Incidentally cured psoriasis in a patient with refractory/relapsed diffuse large B-cell lymphoma receiving CD19 CAR-T cell therapy: a case report

Chimeric antigen receptor T (CAR-T) cell therapy is a new treatment for cancers, but reports on curing immune-related skin diseases are limited. We report a case of successful CAR-T-cell therapy in a patient with refractory/relapsed diffuse large B-cell lymphoma (R/R DLBCL) who was incidentally cured of chronic generalized plaque psoriasis. The patient, a 65-year-old male who had a known history of psoriasis for 45 years, did not receive immunotherapy for psoriasis during this period. Imaging, molecular biology and immunology diagnostics confirmed DLBCL. After several weeks of standard-dose R-CHOP chemotherapy, the patient achieved partial remission, but according to CT, the patient relapsed, and there was no significant improvement in her psoriasis symptoms. Subsequently, the patient was enrolled in the CD19 CAR-T-cell therapy group. Four weeks after CAR-T-cell infusion, the patient's abdominal pain disappeared, and there was a significant improvement in overall skin lesions. One year later, follow-up results indicated complete remission of R/R DLBCL (confirmed by PET-CT), with only minimal residual psoriatic skin lesions limited to the patient's neck. The results of using CAR-T-cell therapy to achieve an incidental cure for psoriasis highlight the potential for exploring cell-based therapies for complex autoinflammatory skin diseases.

Fast Clinical Response of Bimekizumab in Nail Psoriasis: A Retrospective Multicenter 36-Week Real-Life Study

(1) Background/Objectives: Nail psoriasis (NP) is a chronic and difficult-to-treat disease, which causes significant social stigma and impairs the patients' quality of life. Moreover, nail psoriasis is a true therapeutic challenge for clinicians. The presence of nail psoriasis can be part of a severe form of psoriasis and can have predictive value for the development of psoriatic arthritis. Our real-world-evidence multicenter study aims to evaluate the efficacy of bimekizumab in nail psoriasis. (2) Methods: A retrospective analysis of a multicenter observational study included 834 patients affected by moderate-to-severe psoriasis, in 33 Dermatologic Units in Italy, treated with bimekizumab from December 2022 to September 2023. Clinimetric assessments were based on Psoriasis Area and Severity Index (PASI), Dermatology Life Quality Index (DLQI), and Physician's Global Assessment of Fingernail Psoriasis (PGA-F) for the severity of nail psoriasis at 0, 12, 24, and 36 weeks. (3) Results: Psoriatic nail involvement was present in 27.95% of patients. The percentage of patients who achieved a complete clearance of NP in terms of PGA-F 0 was 31.7%, 57%, and 88.5% at week 4, 16, and 36, respectively. PASI 100 was achieved by 32.03% of patients at week 4, by 61.8% at week 16, and by 78.92% of patients at week 36. The mean baseline PASI was 16.24. The mean DLQI values for the entire group of patients at baseline, at week 4, at week 16, and at week 36 were 14.62, 3.02, 0.83, and 0.5, respectively. (4) Conclusions: Therapies that promote the healing of both the skin and nails in a short time can also ensure a lower risk of subsequently developing arthritis which is disabling over time. Bimekizumab proved to be particularly effective to treat NP, with a fast response in terms of complete clearance, with over 88.5% of patients free from NP after 36 weeks. The findings of our real-world study showed that patients with moderate-to-severe PsO and concomitant NP had significantly faster and more substantial improvements in NP up to 36 weeks with respect to previous research findings. Considering the rapid healing of the nail, the dual inhibition of IL17 A and F might have a great value in re-establishing the dysregulation of keratin 17 at the nail level.

Advances in psoriasis research: From pathogenesis to therapeutics

Psoriasis is a chronic inflammatory condition affecting approximately 2 % to 3 % of the global population. The pathogenesis of psoriasis is complex, involving immune dysregulation, hyperproliferation and angiogenesis. It is a multifactorial disease which is influenced by genetic and environmental factors. The development of various therapeutic agents, such as JAK inhibitors, small molecules, and biologics with potential anti-psoriatic properties was possible with the vast understanding of the pathogenesis of psoriasis. Various signalling pathways, including NF-κB, JAK-STAT, S1P, PDE-4, and A3AR that are involved in the pathogenesis of psoriasis as well as the preclinical models utilised in the research of psoriasis have been highlighted in this review. The review also focuses on technological advancements that have contributed to a better understanding of psoriasis. Then, the molecules targeting the respective signalling pathways that are still under clinical trials or recently approved as well as the latest breakthroughs in therapeutic and drug delivery approaches that can contribute to the improvement in the management of psoriasis are highlighted in this review. This review provides an extensive understanding of the current state of research in psoriasis, giving rise to opportunities for researchers to discover future therapeutic breakthroughs and personalised interventions. Efficient treatment options for individuals with psoriasis can be achieved by an extensive understanding of pathogenesis, therapeutic agents, and novel drug delivery strategies.

ERAP1 and ERAP2 gene variants as potential clinical biomarkers of anti-interleukin-17A response in psoriasis vulgaris

BACKGROUND

Interleukin (IL)-17A is a proinflammatory cytokine that plays an essential role in the development of psoriasis. Although treatment with anti-IL-17A monoclonal antibodies has demonstrated high efficacy in patients with psoriasis, not all patients respond equally well, highlighting the need for biomarkers to predict treatment response. Specific single-nucleotide polymorphisms (SNPs) in the genes encoding endoplasmic reticulum aminopeptidases 1 and 2 (ERAP1 and ERAP2) have been associated with psoriasis and other immune-mediated diseases.

OBJECTIVES

To investigate the association between the ERAP1 and ERAP2 genotypes and response to secukinumab treatment in patients with psoriasis.

METHODS

In total, 75 patients with plaque psoriasis were included. All patients were genotyped for the ERAP1 rs27524, rs27044, rs30187, rs2287987 and rs26653 SNPs, the ERAP2 rs2248374 SNP, and the status of the human leucocyte antigen HLA-C*06:02 gene.

RESULTS

Our results demonstrated that individuals with specific ERAP1 and ERAP2 genotypes had a considerably lower response rate to secukinumab treatment. Patients with the ERAP2 rs2248374 GG genotype had a more than sixfold increased risk of treatment failure compared with patients with the rs2248374 AG or AA genotypes. Stratifying for HLA-C*06:02 status, the ERAP2 GG genotype pointed towards an increased risk of treatment failure among HLA-C*06:02-positive patients, although this was not statistically significant.

CONCLUSIONS

Taken together, this unique study breaks new ground by identifying distinct ERAP1 and ERAP2 gene variants that may serve as potential biomarkers for predicting the treatment response to secukinumab in patients with psoriasis. Notably, our data extend existing knowledge by linking specific ERAP1 and ERAP2 gene variants to treatment outcome.

Therapeutic Advances in Psoriasis: From Biologics to Emerging Oral Small Molecules

Psoriasis is a persistent, inflammatory condition affecting millions globally, marked by excessive keratinocyte proliferation, immune cell infiltration, and widespread inflammation. Over the years, therapeutic approaches have developed significantly, shifting from conventional topical treatments and phototherapy to more sophisticated systemic interventions such as biologics and, recently, oral small-molecule drugs. This review seeks to present a comprehensive investigation of the existing psoriasis treatment options, focusing on biologic agents, oral small molecules, and emerging treatments. Several categories of biologic treatments have received regulatory approval for psoriasis, including TNF-α, IL-17, IL-12/23, and IL-23 inhibitors. Biologics have revolutionized the treatment of psoriasis. These targeted therapies offer significant improvement in disease control and quality of life, with acceptable safety profiles. However, limitations such as cost, potential immunogenicity, and administration challenges have driven the exploration of alternative treatment modalities. Oral small molecules, particularly inhibitors of Janus kinase (JAK), have emerged as options due to their convenience and efficacy. These agents represent a paradigm shift in the management of the condition, offering oral administration and targeted action on specific signaling pathways. In addition to existing therapies, the review explores emerging treatments that hold promise for the future of psoriasis care. These include innovative small-molecule inhibitors. Early-stage clinical trials suggest these agents may enhance outcomes for psoriasis patients. In conclusion, the therapeutic landscape of psoriasis is rapidly evolving, emphasizing targeted, patient-centered treatments. Ongoing research and development are expected to lead to more personalized and effective management strategies for this complex condition.

Novel Factors Regulating Proliferation, Migration, and Differentiation of Fibroblasts, Keratinocytes, and Vascular Smooth Muscle Cells during Wound Healing

Chronic diabetic foot ulcers (DFUs) are a significant complication of diabetes mellitus, often leading to amputation, increased morbidity, and a substantial financial burden. Even with the advancements in the treatment of DFU, the risk of amputation still exists, and this occurs due to the presence of gangrene and osteomyelitis. Nonhealing in a chronic DFU is due to decreased angiogenesis, granulation tissue formation, and extracellular matrix remodeling in the presence of persistent inflammation. During wound healing, the proliferation and migration of fibroblasts, smooth muscle cells, and keratinocytes play a critical role in extracellular matrix (ECM) remodeling, angiogenesis, and epithelialization. The molecular factors regulating the migration, proliferation, and differentiation of these cells are scarcely discussed in the literature. The literature review identifies the key factors influencing the proliferation, migration, and differentiation of fibroblasts, keratinocytes, and vascular smooth muscle cells (VSMCs), which are critical in wound healing. This is followed by a discussion on the various novel factors regulating the migration, proliferation, and differentiation of these cells but not in the context of wound healing; however, they may play a role. Using a network analysis, we examined the interactions between various factors, and the findings suggest that the novel factors identified may play a significant role in promoting angiogenesis, granulation tissue formation, and extracellular matrix remodeling during wound healing or DFU healing. However, these interactions warrant further investigation to establish their role alone or synergistically.

DNMT inhibitor, 5-aza-2'-deoxycytidine mitigates di(2-ethylhexyl) phthalate-induced aggravation of psoriasiform inflammation in mice via reduction in global DNA methylation in dermal and peripheral compartments

Psoriasis is classified as an autoimmune disorder characterized by abnormal immune response leading to the development of chronic dermal inflammation. Most individuals have a genetic vulnerability that may be further influenced by epigenetic changes occurring due to multiple variables such as pollutant exposure. Epigenetic modifications such as DNA methylation possess a dynamic nature, enabling cellular differentiation and adaptation by controlling gene expression. Di(2-ethylhexyl) phthalate (DEHP) and psoriatic inflammation are known to cause modification of DNA methylation via DNA methyltransferase (DNMT). However, it is not known whether DEHP, a ubiquitous plasticizer affects psoriatic inflammation via DNMT modulation. Therefore, this study investigated the effect of DNMT inhibitor, 5-aza-2'-deoxycytidine (AZA) on DEHP-induced changes in the expression of DNMT1, global DNA methylation, and anti-/inflammatory parameters (p-STAT3, IL-17A, IL-6, iNOS, IL-10, Foxp3, Nrf2, HO-1) in the skin and the peripheral adaptive/ myeloid immune cells (CD4+ T cells/CD11b+ cells) in imiquimod (IMQ) model of psoriasiform inflammation. Further, psoriasis-associated clinical/histopathological features (ear thickness, ear weight, ear PASI score, MPO activity, and H&E staining of the ear and the back skin) were also analyzed in IMQ model. Our data show that IMQ-treated mice with DEHP exposure had increased DNMT1 expression and DNA methylation which was associated with elevated inflammatory (p-STAT3, IL-17A, IL-6, iNOS) and downregulated anti-inflammatory mediators (IL-10, Foxp3, Nrf2, HO-1) in the peripheral immune cells (CD4+ T cells/CD11b+ cells) and the skin as compared to IMQ-treated mice. Treatment with DNMT1 inhibitor caused reduction in inflammatory and elevation in anti-inflammatory parameters with significant improvement in clinical/histopathological symptoms in both IMQ-treated and DEHP-exposed IMQ-treated mice. In conclusion, our study shows strong evidence indicating that DNMT1 plays an important role in DEHP-induced exacerbation of psoriasiform inflammation in mice through hypermethylation of DNA.

Basophils Play a Protective Role in the Recovery of Skin Barrier Function from Mechanical Injury in Mice

Physical trauma disrupts skin barrier function. How the skin barrier recovers is not fully understood. We evaluated in mice the mechanism of skin barrier recovery after mechanical injury inflicted by tape stripping. Tape stripping disrupted skin barrier function as evidenced by increased transepidermal water loss. We show that tape stripping induces IL-1-, IL-23-, and TCRγδ+-dependent upregulation of cutaneous Il17a and Il22 expression. We demonstrate that IL-17A and IL-22 induce epidermal hyperplasia, promote neutrophil recruitment, and delay skin barrier function recovery. Neutrophil depletion improved the recovery of skin barrier function and decreased epidermal hyperplasia. Single-cell RNA sequencing and flow cytometry analysis of skin cells revealed basophil infiltration into tape-stripped skin. Basophil depletion upregulated Il17a expression, increased neutrophil infiltration, and delayed skin barrier recovery. Comparative analysis of genes differentially expressed in tape-stripped skin of basophil-depleted mice and Il17a-/- mice indicated that basophils counteract the effects of IL-17A on the expression of epidermal and lipid metabolism genes important for skin barrier integrity. Our results demonstrate that basophils play a protective role by downregulating Il17a expression after mechanical skin injury, thereby counteracting the adverse effect of IL-17A on skin barrier function recovery, and suggest interventions to accelerate this recovery.

Evaluation of Kynu, Defb2, Camp, and Penk Expression Levels as Psoriasis Marker in the Imiquimod-Induced Psoriasis Model

Background

Psoriasis is a noncontagious auto-inflammatory chronic skin disease. So far, some of the inflammatory genes were upregulated in mouse model of psoriasis. This study examined changes in skin mRNA expression of L-kynureninase (Kynu), cathelicidin antimicrobial peptide (Camp), beta-defensin 2 (Defb2), and proenkephalin (Penk) in a mouse model of imiquimod-induced psoriasis.

Materials and Methods

Tree groups of C57BL/6 female mice were allocated. The imiquimod (IMQ) cream was administered to the mice dorsal skin of the two groups to induce psoriatic inflammation. In the treatment group, IMQ was administered 10 min after hydrogel-containing M7 anti-IL-17A aptamer treatment. Vaseline (Vas) was administered to the negative control group. The psoriatic skin lesions were evaluated based on the psoriasis area severity index (PASI) score, histopathology, and mRNA expression levels of Kynu, Camp, Defb2, and Penk using real-time PCR. In order to assess the systemic response, the spleen and lymph node indexes were also evaluated.

Results

The PASI and epidermal thickness scores were 6.01 and 1.96, respectively, in the IMQ group, and they significantly decreased after aptamer administration to 1.15 and 0.90, respectively (P < 0.05). Spleen and lymph node indexes showed an increase in the IMQ group, followed by a slight decrease after aptamer treatment (P > 0.05). Additionally, the mRNA expression levels of Kynu, Defb2, Camp, and Penk genes in the IMQ-treated region showed a significant 2.70, 4.56, 3.29, and 2.61-fold increase relative to the Vas mice, respectively (P < 0.05). The aptamer-treated region exhibited a significant decrease in these gene expression levels (P < 0.05). A positive correlation was found between Kynu, Penk, and Camp expression levels and erythema, as well as Camp expression with PASI, scaling, and thickness (P < 0.05).

Conclusion

According to our results, it seems that Kynu, Camp, and Penk can be considered appropriate markers for the evaluation of psoriasis in IMQ-induced psoriasis. Also, the anti-IL-17 aptamer downregulated these important genes in this mouse model.

Wogonin ameliorates the proliferation, inflammatory response, and pyroptosis in keratinocytes via NOD-like receptor family pyrin domain containing 3/Caspase-1/Gasdermin-D pathway

BACKGROUND

Psoriasis refers to a highly prevalent and immunologically mediated dermatosis with considerable deterioration in life quality. Wogonin, a sort of flavonoid, has been mentioned to elicit protective activities in skin diseases. However, whether Wogonin is implicated in the treatment of psoriasis and its specific mechanisms are not fully understood.

AIM

The present work attempted to elaborate the role of Wogonin during the process of psoriasis and to concentrate on the associated action mechanism.

METHODS

Cell counting kit-8 (CCK-8) method was initially applied to assay the viability of human keratinocyte HaCaT cells treated by varying concentrations of Wogonin. To mimic psoriasis in vitro, HaCaT cells were exposed to M5 cytokines. CCK-8 and 5-Ethynyl-2'-deoxyuridine  assays were adopted for the measurement of cell proliferation. Inflammatory levels were examined with enzyme-linked immunosorbent assay. Immunofluorescence staining tested nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) and Caspase-1 expressions. Western blot examined the protein expressions of proliferation-, inflammation-, pyroptosis-associated factors, and NLRP3.

RESULTS

Wogonin treatment antagonized the proliferation, inflammatory response, and NLRP3/caspase-1/Gasdermin-D (GSDMD)-mediated pyroptosis in M5-challenged HaCaT cells. Besides, NLRP3 elevation partially abrogated the effects of Wogonin on M5-induced proliferation, inflammatory response, and NLRP3/caspase-1/GSDMD-mediated pyroptosis in HaCaT cells.

CONCLUSION

In a word, Wogonin might exert anti-proliferation, anti-inflammatory and anti-pyroptosis activities in M5-induced cell model of psoriasis and the blockade of NLRP3/Caspase-1/GSDMD pathway might be recognized as a potential mechanism underlying the protective mechanism of Wogonin in psoriasis, suggesting Wogonin as a prospective anti-psoriasis drug.

Targeting STING in dendritic cells alleviates psoriatic inflammation by suppressing IL-17A production

Psoriasis is a common chronic inflammatory skin disease driven by the aberrant activation of dendritic cells (DCs) and T cells, ultimately leading to increased production of cytokines such as interleukin (IL)-23 and IL-17A. It is established that the cGAS-STING pathway is essential for psoriatic inflammation, however, the specific role of cGAS-STING signaling in DCs within this context remains unclear. In this study, we demonstrated the upregulation of cGAS-STING signaling in psoriatic lesions by analyzing samples from both clinical patients and imiquimod (IMQ)-treated mice. Using a conditional Sting-knockout transgenic mouse model, we elucidated the impact of cGAS-STING signaling in DCs on the activation of IL-17- and IFN-γ-producing T cells in psoriatic inflammation. Ablation of the Sting hampers DC activation leads to decreased numbers of IL-17-producing T cells and Th1 cells, and thus subsequently attenuates psoriatic inflammation in the IMQ-induced mouse model. Furthermore, we explored the therapeutic potential of the STING inhibitor C-176, which reduces psoriatic inflammation and enhances the anti-IL-17A therapeutic response. Our results underscore the critical role of cGAS-STING signaling in DCs in driving psoriatic inflammation and highlight a promising psoriasis treatment.

Piperlongumine regulates genes involved in the skin barrier in epidermal keratinocyte HaCaT cells

Given that the skin is the largest tissue in the human body, performing external barrier functions with innate and adaptive immunity and undergoing substantial changes during aging, it is under investigation as a major target of various bioactive molecules. In the present study, we examined the biological activity of the senolytic piperlongumine by analyzing alterations in mRNA expression of notable skin genes using transformed aneuploid immortal epidermal keratinocytes, HaCaT cells. We observed that piperlongumine increased the mRNA expression of genes playing critical roles in skin barrier function. In addition, piperlongumine increased expression enzymes involved in the synthesis of ceramide, a major component of intercellular lipids. Furthermore, we measured the protein levels of various cytokines secreted by epidermal keratinocytes and found changes in the release of GRO-αβγ, CCL5, and MCP1. Additionally, we observed that piperlongumine treatment modulated the expression of keratinocyte-specific aging markers and influenced telomerase activity. Based on these findings, piperlongumine could regulate the physiological activity of epidermal keratinocytes to induce beneficial effects in human skin by regulating important skin-related genes.

LncRNA MIR181A2HG negatively regulates human keratinocytes proliferation by binding SRSF1

Psoriasis is a common chronic inflammatory skin disease. Abnormal proliferation of keratinocytes plays an important role in the pathogenesis of psoriasis. Long non-coding RNAs (lncRNAs) are involved in the regulation of a variety of cell biological processes. The purpose of this study was to investigate the potential role of lncRNA MIR181A2HG in the proliferation of human keratinocytes. qRT-PCR and Western blotting were performed to measure the expression levels of MIR181A2HG, SRSF1, KRT6, and KRT16 in tissue specimens and HaCaT keratinocytes. The effects of MIR181A2HG on HaCaT keratinocytes proliferation were evaluated using Cell Counting Kit-8 (CCK-8) assays, 5-Ethynyl-2'-deoxyuridine (EdU) incorporation, and cell-cycle assays. RNA pulldown-mass spectrometry (MS) was applied to identify the proteins interacting with MIR181A2HG. RNA pull-down-Western blotting and RNA immunoprecipitation coupled with real-time quantitative reverse transcription-PCR (RIP-qRT-PCR) assays were used to determine the interactions between MIR181A2HG and its RNA-binding proteins (RBPs). MIR181A2HG was down-regulated in psoriasis tissues. MIR181A2HG overexpression induced G0/G1 and G2/M phase cell cycle arrest and decreased the protein levels of KRT6, KRT16, Cyclin D1, CDK4, and Cyclin A2 in HaCaT keratinocytes. MIR181A2HG knockdown showed the opposite effect. By using RNA pulldown-MS, 356 proteins were identified to interact with MIR181A2HG potentially. Bioinformatics analysis showed that NOP56 and SRSF1 may be RNA binding proteins (RBPs) that may be interact with MIR181A2HG. Furthermore, by using RNA pull-down-Western blotting and RIP-qRT-PCR, SRSF1 was determined to interact with MIR181A2HG. Moreover, silencing of SRSF1 inhibited keratinocytes proliferation, which could be reversed with the knockdown of MIR181A2HG. Our findings indicated that MIR181A2HG can negatively regulate HaCaT keratinocytes proliferation by binding SRSF1, suggesting that MIR181A2HG and SRSF1 may serve as potential targets for the treatment of psoriasis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-024-00621-6.

CD169+ Skin Macrophages Function as a Specialized Subpopulation in Promoting Psoriasis-like Skin Disease in Mice

Skin macrophages are critical to maintain and restore skin homeostasis. They serve as major producers of cytokines and chemokines in the skin, participating in diverse biological processes such as wound healing and psoriasis. The heterogeneity and functional diversity of macrophage subpopulations endow them with multifaceted roles in psoriasis development. A distinct subpopulation of skin macrophages, characterized by high expression of CD169, has been reported to exist in both mouse and human skin. However, its role in psoriasis remains unknown. Here, we report that CD169+ macrophages exhibit increased abundance in imiquimod (IMQ) induced psoriasis-like skin lesions. Specific depletion of CD169+ macrophages in CD169-ditheria toxin receptor (CD169-DTR) mice inhibits IMQ-induced psoriasis, resulting in milder symptoms, diminished proinflammatory cytokine levels and reduced proportion of Th17 cells within the skin lesions. Furthermore, transcriptomic analysis uncovers enhanced activity in CD169+ macrophages when compared with CD169- macrophages, characterized by upregulated genes that are associated with cell activation and cell metabolism. Mechanistically, CD169+ macrophages isolated from IMQ-induced skin lesions produce more proinflammatory cytokines and exhibit enhanced ability to promote Th17 cell differentiation in vitro. Collectively, our findings highlight the crucial involvement of CD169+ macrophages in psoriasis development and offer novel insights into the heterogeneity of skin macrophages in the context of psoriasis.

Cang-ai volatile oil ameliorates imiquimod-induced psoriatic skin lesions by suppressing the ILC3s

ETHNOPHARMACOLOGICAL RELEVANCE

Cang-ai volatile oil (CAVO) is an aromatic Chinese medicine with potent antibacterial and immune regulatory properties. While CAVO has been used to treat upper respiratory tract infections, depression, otomycosis, and bacterial infections in the skin, its effect on psoriasis is unknown.

AIM OF THE STUDY

This study explores the effect and mechanism of CAVO in psoriasis intervention.

MATERIAL AND METHODS

The effect of CAVO on the expression of IL-6 and IL-1β was assessed in TNF-α-induced HaCaT cells using enzyme-linked immunosorbent assay (ELISA). Mice were given imiquimod (IMQ) and administered orally with different CAVO doses (0.03 and 0.06 g/kg) for 5 days. The levels of inflammatory cytokines related to group-3 innate lymphoid cells (ILC3s) in the skin were assessed using hematoxylin and eosin (H&E) staining, ELISA, and western blotting (WB). The frequency of ILC3s in mice splenocytes and skin cells was evaluated using flow cytometry.

RESULTS

The results demonstrated that CAVO decreased the expression of IL-6 and IL-1β in TNF-α- induced HaCaT cells. CAVO significantly reduced the severity of psoriatic symptoms in IMQ-induced mice. The expression of inflammatory cytokines in the skin, such as IL-1β, IL-6, IL-8, IL-22, IL-23, and IL-17 A were decreased, whereas IL-10 levels were increased. The mRNA expressions of TNF-α, IL-23 A, IL-23 R, IL-22, IL-17 A, and RORγt were down-regulated in skin tissues. CAVO also decreased the levels of NF-κB, STAT3, and JAK2 proteins.

CONCLUSIONS

CAVO potentially inhibits ILC3s activation to relieve IMQ-induced psoriasis in mice. These effects might be attributed to inhibiting the activation of NF-κB, STAT3, and JAK2 signaling pathways.

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.

Metabolic dysfunction associated steatotic liver disease in patients with plaque psoriasis: a case-control study and serological comparison

Background

The relationship between plaque psoriasis and both MASLD and lean MASLD has not been sufficiently explored in the current literature.

Method

This retrospective and observational study was carried out from January 2021 to January 2023 at The First Affiliated Hospital of Zhejiang Chinese Medical University. Patients diagnosed with plaque psoriasis and a control group consisting of individuals undergoing routine physical examinations were enrolled. The incidence of MASLD and lean MASLD among these groups was compared. Additionally, patients with plaque psoriasis were divided into those with MASLD, those with lean MASLD, and a control group with only psoriasis for a serological comparative analysis.

Results

The incidence of MASLD in the observation group and the control group was 43.67% (69/158) and 22.15% (35/158), respectively (p < 0.01). Furthermore, the incidence of lean MASLD within the observation group and the control group was 10.76% (17/158) and 4.43% (7/158), respectively (p < 0.01). After controlling for potential confounding variables, plaque psoriasis was identified as an independent risk factor for MASLD with an odds ratio of 1.88 (95% cl: 1.10-3.21). In terms of serological comparison, compared to the simple psoriasis group, we observed a significant elevation in the tumor marker CYFRA21-1 levels in both groups compared to the control group with simple psoriasis (p < 0.01). Moreover, the MASLD group exhibited elevated levels of inflammatory markers and psoriasis score, whereas these effects were mitigated in the lean MASLD group.

Conclusion

The prevalence of MASLD and lean MASLD is higher among patients with psoriasis. Those suffering from psoriasis along with MASLD show increased psoriasis scores and inflammatory markers compared to those without metabolic disorders. MASLD likely worsens psoriasis conditions, indicating the necessity of targeted health education for affected individuals to reduce the risk of MASLD, this education should include guidelines on exercise and diet. In serological assessments, elevated levels of cytokeratin 19 fragment (CYFRA21-1) were noted in both MASLD and lean MASLD groups, implying a potential synergistic role between psoriasis and MASLD.

Discovery of biomarkers in the psoriasis through machine learning and dynamic immune infiltration in three types of skin lesions

Introduction

Psoriasis is a chronic skin disease characterized by unique scaling plaques. However, during the acute phase, psoriatic lesions exhibit eczematous changes, making them difficult to distinguish from atopic dermatitis, which poses challenges for the selection of biological agents. This study aimed to identify potential diagnostic genes in psoriatic lesions and investigate their clinical significance.

Methods

GSE182740 datasets from the GEO database were analyzed for differential analysis; machine learning algorithms (SVM-RFE and LASSO regression models) are used to screen for diagnostic markers; CIBERSORTx is used to determine the dynamic changes of 22 different immune cell components in normal skin lesions, psoriatic non-lesional skin, and psoriatic lesional skin, as well as the expression of the diagnostic genes in 10 major immune cells, and real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry are used to validate results.

Results

We obtained 580 differentially expressed genes (DEGs) in the skin lesion and non-lesion of psoriasis patients, 813 DEGs in mixed patients between non-lesions and lesions, and 96 DEGs in the skin lesion and non-lesion of atopic dermatitis, respectively. Then 144 specific DEGs in psoriasis via a Veen diagram were identified. Ultimately, UGGT1, CCNE1, MMP9 and ARHGEF28 are identified for potential diagnostic genes from these 144 specific DEGs. The value of the selected diagnostic genes was verified by receiver operating characteristic (ROC) curves with expanded samples. The the area under the ROC curve (AUC) exceeded 0.7 for the four diagnosis genes. RT-qPCR results showed that compared to normal human epidermis, the expression of UGGT1, CCNE1, and MMP9 was significantly increased in patients with psoriasis, while ARHGEF28 expression was significantly decreased. Notably, the results of CIBERSORTx showed that CCNE1 was highly expressed in CD4+ T cells and neutrophils, ARHGEF28 was also expressed in mast cells. Additionally, CCNE1 was strongly correlated with IL-17/CXCL8/9/10 and CCL20. Immunohistochemical results showed increased nuclear expression of CCNE1 in psoriatic epidermal cells relative to normal.

Conclusion

Based on the performance of the four genes in ROC curves and their expression in immune cells from patients with psoriasis, we suggest that CCNE1 possess higher diagnostic value.

IL-6 Up-Regulates Expression of LIM-Domain Only Protein 4 in Psoriatic Keratinocytes through Activation of the MEK/ERK/NF-κB Pathway

Psoriasis is a chronic inflammatory skin disease characterized by the activation of keratinocytes and the infiltration of immune cells. Overexpression of the transcription factor LIM-domain only protein 4 (LMO4) promoted by IL-23 has critical roles in regulating the proliferation and differentiation of psoriatic keratinocytes. IL-6, an autocrine cytokine in psoriatic epidermis, is a key mediator of IL-23/T helper 17-driven cutaneous inflammation. However, little is known about how IL-6 regulates the up-regulation of LMO4 expression in psoriatic lesions. In this study, human immortalized keratinocyte cells, clinical biopsy specimens, and an animal model of psoriasis induced by imiquimod cream were used to investigate the role of IL-6 in the regulation of keratinocyte proliferation and differentiation. Psoriatic epidermis showed abnormal expression of IL-6 and LMO4. IL-6 up-regulated the expression of LMO4 and promoted keratinocyte proliferation and differentiation. Furthermore, in vitro and in vivo studies showed that IL-6 up-regulates LMO4 expression by activating the mitogen-activated extracellular signal-regulated kinase (MEK)/extracellular signal-regulated kinase (ERK)/NF-κB signaling pathway. These results suggest that IL-6 can activate the NF-κB signaling pathway, up-regulate the expression of LMO4, lead to abnormal proliferation and differentiation of keratinocytes, and promote the occurrence and development of psoriasis.

Inflammatory Memory in Chronic Skin Disease

Inflammation is a hallmark of remitting-relapsing dermatological diseases. Although a large emphasis has been placed on adaptive immune cells as mediators of relapse, evidence in epithelial and innate immune biology suggests that disease memory is widespread. In this study, we bring to the fore the concept of inflammatory memory or nonspecific training of long-lived cells in the skin, highlighting the epigenetic and other mechanisms that propagate memory at the cellular level. We place these findings in the context of psoriasis, a prototypic flaring disease known to have localized memory, and underscore the importance of targeting memory to limit disease flares.

Gasdermin B (GSDMB) in psoriatic patients-a preliminary comprehensive study on human serum, urine and skin

Psoriasis is one of the most common skin diseases and a crucial issue to manage in contemporary dermatology. The search for the details of its pathogenesis, markers and treatment is continuously ongoing. Our aim was to investigate the role of gasdermin B (GSDMB) in psoriasis, the second protein from the gasdermin family, involved in cell death and proliferation. GSDMB serum and urinary concentrations have never been studied in psoriatics, neither tissue expression of GSDMB by immunohistochemistry. The study included 60 psoriatic patients and 30 volunteers without dermatoses as controls. The serum and urinary GSDMB were evaluated by ELISA. Tissue expression of GSDMB was analyzed by immunohistochemistry. The serum and absolute urine concentrations of GSDMB were significantly higher in psoriatic patients than controls without skin diseases (p = 0.0137, p = 0.039 respectively). Urinary GSDMB/creatinine concentration ratio was significantly lower in patients compared to controls (p = 0.0241). The expression of GSDMB in the dermis and epidermis was significantly more prevalent in psoriatic plaque compared to the non-lesional skin and healthy skin of controls (p = 0.0012, p = 0.017, respectively). Serum GSDMB correlated positively with the age of patients (R = 0.41; p = 0.001). Our study adds to the current state of knowledge about psoriasis concerning the potential involvement of GSDMB. Possibly it could be engaged in keratinocytes migration, which requires further research. Elevated serum GSDMB and decreased urinary GSDMB/creatinine concentration ratio could potentially be investigated as psoriasis biomarkers. GSDMB could be investigated in the future as a potential therapeutic target.

Rh family C glycoprotein contributes to psoriatic inflammation through regulating the dysdifferentiation and cytokine secretion of keratinocytes

BACKGROUND

Keratinocyte dysdifferentiation and proinflammatory cytokine production play a central role in psoriatic inflammation. According to recent studies, the Rh family C glycoprotein (RHCG) enhances cell proliferation and disrupts cell differentiation. However, the specific role of RHCG psoriasis development remains unclear.

OBJECTIVE

We here explored the effect of RHCG on keratinocytes under psoriatic inflammation.

METHODS

The cell counting kit‑8 assay was conducted to assess proliferation. RHCG protein expression was assessed through western blotting and enzyme-linked immunosorbent assays. The expression of proinflammatory cytokines and differentiation markers was analyzed through a quantitative reverse-transcription polymerase chain reaction.

RESULTS

Both RHCG mRNA and protein levels increased in psoriatic skin. Notably, cultured keratinocytes treated with an M5 cocktail, which mimics psoriatic inflammation, exhibited higher RHCG expression. Furthermore, RHCG overexpression promoted keratinocyte proliferation, accompanied by an increase in the production of interleukin (IL)-1β, IL-6, and IL-8, and tumor necrosis factor-α. RHCG overexpression also resulted in higher expression of keratin 17, a differentiation marker. Conversely, RHCG gene knockdown reduced keratinocyte proliferation and cytokine secretion. RHCG inhibition in cells recovered both keratin 1 and loricrin expression. Additionally, RHCG overexpression facilitated the phosphorylation of nuclear factor-kappa B and extracellular signal-regulated protein kinase signaling pathways. Importantly, when these signaling pathways were inhibited, the effect of RHCG on keratinocytes was attenuated.

CONCLUSION

These findings support the substantial role of RHCG in psoriatic inflammation development and suggest that RHCG serves as a potential target for psoriasis treatment.

Bcat2-Mediated Branched-Chain Amino Acid Catabolism Is Linked to the Aggravated Inflammation in Obese with Psoriasis Mice

SCOPE

The global prevalence of obesity has significantly increased, presenting a major health challenge. High-fat diet (HFD)-induced obesity is closely related to the disease severity of psoriasis, but the mechanism is not fully understood.

METHODS AND RESULTS

The study utilizes the HFD-induced obesity model along with an imiquimod (IMQ)-induced psoriasis-like mouse model (HFD-IMQ) to conduct transcriptomics and metabolomic analyses. HFD-induced obese mice exhibits more severe psoriasis-like lesions compared to normal diet (ND)-IMQ mice. The expression of genes of the IL-17 signaling pathway (IL-17A, IL-17F, S100A9, CCL20, CXCL1) is significantly upregulated, leading to an accumulation of T cells and neutrophils in the skin. Moreover, the study finds that there is an inhibition of the branched-chain amino acids (BCAAs) catabolism pathway, and the key gene branched-chain amino transferase 2 (Bcat2) is significantly downregulated, and the levels of leucine, isoleucine, and valine are elevated in the HFD-IMQ mice. Furthermore, the study finds that the peroxisome proliferator-activated receptor gamma (PPAR γ) is inhibited, while STAT3 activity is promoted in HFD-IMQ mice.

CONCLUSION

HFD-induced obesity significantly amplifies IL-17 signaling and exacerbates psoriasis, with a potential role played by Bcat2-mediated BCAAs metabolism. The study suggests that BCAA catabolism and PPAR γ-STAT3 exacerbate inflammation in psoriasis with obesity.

Deciphering the causal association and co-disease mechanisms between psoriasis and breast cancer

Background

Prior research has indicated a link between psoriasis and the susceptibility to breast cancer (BC); however, a definitive causal relationship remains elusive. This study sought to elucidate the causal connection and shared underlying mechanisms between psoriasis and BC through bidirectional Mendelian randomization (MR) and bioinformatic approaches.

Methods

We employed a bidirectional MR approach to examine the potential causal connection between psoriasis and BC. Genetic data pertaining to psoriasis and BC were sourced from extensive published genome-wide association studies. The inverse -variance weighted or wald ratio served as the primary method for estimating causal effects. Sensitivity analysis of the MR results was applied with multiple methods. Leveraged datasets from the Gene Expression Omnibus and the Cancer Genome Atlas repositories to identify common differentially expressed genes, shedding light on the shared mechanisms underlying these two conditions.

Results

The MR analysis revealed that when considering psoriasis as an exposure factor, the incidences of BC (OR=1.027) and estrogen receptor negative (ER-) BC (OR=1.054) were higher than in the general population. When using Her2+ BC as an exposure factor, the risk of psoriasis was 0.822 times higher (OR=0.822) than in the general population. Sensitivity analysis indicated that the results were robust. Transcriptome analysis showed that CXCL13 and CCL20 were activated in both BC and psoriasis. Both diseases were also linked to neutrophil chemotaxis, the IL-17 pathway, and the chemokine pathway.

Conclusion

The results suggest that psoriasis may increase the risk of BC, especially ER- BC, while reverse MR suggests a decreased risk of psoriasis in Her2+ BC. Transcriptome analysis revealed a shared mechanism between psoriasis and BC.