Pathogenic sphingosine 1-phosphate pathway in psoriasis: a critical review of its pathogenic significance and potential as a therapeutic target

Advancing psoriasis drug delivery through topical liposomes

Psoriasis, recognized as a chronic inflammatory skin disorder, disrupts immune system functionality. Global estimates by the World Psoriasis Day consortium indicate its impact on approximately 130 million people, constituting 4 to 5 percent of the worldwide population. Conventional drug delivery systems, mainly designed to alleviate psoriasis symptoms, fall short in achieving targeted action and optimal bioavailability due to inherent challenges such as the drug's brief half-life, instability, and a deficiency in ensuring both safety and efficacy. Liposomes, employed in drug delivery systems, emerge as highly promising carriers for augmenting the therapeutic efficacy of topically applied drugs. These small unilamellar vesicles demonstrate enhanced penetration capabilities, facilitating drug delivery through the stratum corneum layer of skin. This comprehensive review article illuminates diverse facets of liposomes as a promising drug delivery system to treat psoriasis. Addressing various aspects such as formulation strategies, encapsulation techniques, and targeted delivery, the review underscores the potential of liposomes in enhancing the efficacy and specificity of psoriasis treatments.

In Silico Screening of Phytochemicals as Potential Inhibitors of the JAK/STATs Pathway in Psoriasis

The skin is a dynamic tissue that consists of different layers such as stratum corneum, the site for keratinocyte development and maturation for the natural changeover of skin. In psoriasis, this natural development of keratinocytes gets disturbed and aggregation of nucleated keratinocytes takes place in the epidermis of the skin, leading to the presence of scaly skin, which makes the patient physically, socially, and psychologically ill. Various natural, semisynthetic, and synthetic treatments are available. Still, semisynthetic or synthetic are mainly used to treat psoriasis with side effects on different parts of the body, which is life threatening. Various molecular target sites are getting upregulated such as Janus kinase/Signal transducer and activator of transcription (JAK/STATs), phosphodiesterase 4 (PDE4), mitogen-activated protein kinase (MAPK), platelet selectin (Pan Selectin), Tumor Necrosis Factor Alpha (TNF-α), Interleukin-23 (IL-23), Interleukin-17 (IL-17), and Tyrosine Kinase 2 (Tyk2) in psoriasis. Plants and their bioactive compounds of flavonoids, alkaloids, resins, tannins, glycosides, and terpenoids category are used in the treatment of psoriasis as topical, oral, and biological forms. Using a computational approach, the inhibition of these molecular targets can be studied and potential molecules can be identified. This research article aims to find out the potential molecules that can inhibit the molecular sites and are effective than synthetic ones.

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.

S1PR1 mediates Th17 cell migration from the thymus to the skin in health and disease

Th17 cells play crucial roles in host defense and the pathogenesis of autoimmune diseases in the skin. While their differentiation mechanisms have been extensively studied, the origin of skin Th17 cells remains unclear. In this study, we analyzed single-cell RNA-sequencing data and identify the presence of Th17 cells in the human thymus. Thymic Th17 cells were characterized by high expression levels of Sphingosine-1-Phosphate Receptor 1 (S1PR1), a receptor crucial for T cell egress from lymphoid tissues. In mice, Th17 cell-specific knockout of S1pr1 resulted in the accumulation of Th17 cells in the thymus and a corresponding decrease in their numbers in the skin. Th17 cells that accumulated in the thymus exhibited a lower IL-17A production capacity compared to those in the skin, indicating that the local environment in the skin is important for maintaining the Th17 cell phenotype. Additionally, using a murine psoriasis model, we demonstrated that Th17 cell-specific knockout of S1pr1 reduced their migration to the inflamed skin, thereby ameliorating disease progression. Collectively, our data suggest that S1PR1 mediates Th17 cell migration from the thymus to the skin, thereby modulating their functional engagement in both homeostatic and inflammatory conditions.

Promising strategies in natural products treatments of psoriasis-update

Psoriasis is a chronic, relapsing, inflammatory skin disease and has been increasing year by year. It is linked to other serious illnesses, such as psoriatic arthritis, cardiometabolic syndrome, and depression, resulting in a notable decrease in the quality of life for patients. Existing therapies merely alleviate symptoms, rather than providing a cure. An in-depth under-standing of the pathogenesis of psoriasis is helpful to discover new therapeutic targets and develop effective novel therapeutic agents, so it has important clinical significance. This article reviews the new progress in the study of pathogenesis and natural products of psoriasis in recent years. These natural products were summarized, mainly classified as terpenoids, polyphenols and alkaloids. However, the translation of experimental results to the clinic takes a long way to go.

Identification of gene signatures and molecular mechanisms underlying the mutual exclusion between psoriasis and leprosy

Leprosy and psoriasis rarely coexist, the specific molecular mechanisms underlying their mutual exclusion have not been extensively investigated. This study aimed to reveal the underlying mechanism responsible for the mutual exclusion between psoriasis and leprosy. We obtained leprosy and psoriasis data from ArrayExpress and GEO database. Differential expression analysis was conducted separately on the leprosy and psoriasis using DEseq2. Differentially expressed genes (DEGs) with opposite expression patterns in psoriasis and leprosy were identified, which could potentially involve in their mutual exclusion. Enrichment analysis was performed on these candidate mutually exclusive genes, and a protein-protein interaction (PPI) network was constructed to identify hub genes. The expression of these hub genes was further validated in an external dataset to obtain the critical mutually exclusive genes. Additionally, immune cell infiltration in psoriasis and leprosy was analyzed using single-sample gene set enrichment analysis (ssGSEA), and the correlation between critical mutually exclusive genes and immune cells was also examined. Finally, the expression pattern of critical mutually exclusive genes was evaluated in a single-cell transcriptome dataset. We identified 1098 DEGs in the leprosy dataset and 3839 DEGs in the psoriasis dataset. 48 candidate mutually exclusive genes were identified by taking the intersection. Enrichment analysis revealed that these genes were involved in cholesterol metabolism pathways. Through PPI network analysis, we identified APOE, CYP27A1, FADS1, and SOAT1 as hub genes. APOE, CYP27A1, and SOAT1 were subsequently validated as critical mutually exclusive genes on both internal and external datasets. Analysis of immune cell infiltration indicated higher abundance of 16 immune cell types in psoriasis and leprosy compared to normal controls. The abundance of 6 immune cell types in psoriasis and leprosy positively correlated with the expression levels of APOE and CYP27A1. Single-cell data analysis demonstrated that critical mutually exclusive genes were predominantly expressed in Schwann cells and fibroblasts. This study identified APOE, CYP27A1, and SOAT1 as critical mutually exclusive genes. Cholesterol metabolism pathway illustrated the possible mechanism of the inverse association of psoriasis and leprosy. The findings of this study provide a basis for identifying mechanisms and therapeutic targets for psoriasis.

Emerging Oral Therapies for the Treatment of Psoriasis: A Review of Pipeline Agents

The introduction of biologic agents for the treatment of psoriasis has revolutionized the current treatment landscape, targeting cytokines in the interleukin (IL)-23/IL-17 pathway and demonstrating strong efficacy and safety profiles in clinical trials. These agents however are costly, are associated with a risk of immunogenicity, and require administration by intravenous or subcutaneous injection, limiting their use among patients. Oral therapies, specifically small molecule and microbiome therapeutics, have the potential to be more convenient and cost-effective agents for patients and have been a focus of development in recent years, with few targeted oral medications available for the disease. In this manuscript, we review pipeline oral therapies for psoriasis identified through a search of ClinicalTrials.gov (30 June 2022-1 October 2023). Available preclinical and clinical trial data on each therapeutic agent are discussed. Small molecules under development include tumor necrosis factor inhibitors, IL-23 inhibitors, IL-17 inhibitors, phosphodiesterase-4 inhibitors, Janus kinase inhibitors, A3 adenosine receptor agonists, and sphingosine-1-phosphate receptor 1 agonists, several of which are entering phase III trials. Oral microbials have also demonstrated success in early phase studies. As new oral therapies emerge for the treatment of psoriasis, real-world data and comparative trials are needed to better inform their use among patients.

The Role of Sphingolipids and Sphingosine-1-phosphate-Sphingosine-1-phosphate-receptor Signaling in Psoriasis

Psoriasis is a long-lasting skin condition characterized by redness and thick silver scales on the skin's surface. It involves various skin cells, including keratinocytes, dendritic cells, T lymphocytes, and neutrophils. The treatments for psoriasis range from topical to systemic therapies, but they only alleviate the symptoms and do not provide a fundamental cure. Moreover, systemic treatments have the disadvantage of suppressing the entire body's immune system. Therefore, a new treatment strategy with minimal impact on the immune system is required. Recent studies have shown that sphingolipid metabolites, particularly ceramide and sphingosine-1-phosphate (S1P), play a significant role in psoriasis. Specific S1P-S1P-receptor (S1PR) signaling pathways have been identified as crucial to psoriasis inflammation. Based on these findings, S1PR modulators have been investigated and have been found to improve psoriasis inflammation. This review will discuss the metabolic pathways of sphingolipids, the individual functions of these metabolites, and their potential as a new therapeutic approach to psoriasis.

Navigating the landscape of psoriasis therapy: novel targeted pathways and emerging trends

INTRODUCTION

Psoriasis is a chronic, inflammatory, non-communicable skin disorder that affects a patient's social and emotional well-being. It is characterized by hyperproliferation of keratinocytes, irregular shedding of skin cells, and abnormal invasion of inflammatory mediators. The treatment strategy is designed based on the severity of the disease condition starting from topical, phototherapy, systemic, and biologics. In recent years, extensive research into the underlying mechanisms of psoriasis has led to significant advancement in treatment options from small molecules to biologics.

AREA COVERED

This review focuses on intracellular and molecular mechanisms such as AhR, A3AR, RIP1, CGRP, and S1P that serve as novel pharmacological targets for psoriasis. Moreover, new molecules are approved or are under clinical investigation to interfere with these target mechanisms.

EXPERT OPINION

A detailed understanding of signaling pathways provides potential targets and molecular mechanisms for the inflammatory cascade in psoriasis. This has led to the development of small molecules targeting specific pathways. Further, the combination of nanotechnology can assist in dose reduction leading to reduced adverse effects in the management of psoriasis.