Transcription Factor Retinoid-Related Orphan Receptor γt: A Promising Target for the Treatment of Psoriasis

Innovative Approaches to Psoriasis: Small Molecules Targeting Key Signaling Pathways

BACKGROUND

Psoriasis (Pso) is a chronic, immune-mediated dermatological condition characterized by dysregulated inflammatory responses and the hyperproliferation of keratinocytes. Biologics, which target specific cytokines such as IL-17 and IL-23, have revolutionized the management by addressing key drivers of its pathophysiology. Despite their efficacy, biologics are not without limitations, including the need for intermittent administration and ongoing monitoring. In contrast, small molecules offer a promising alternative by selectively inhibiting key signaling pathways that modulate pro-inflammatory cytokines involved in the inflammatory cascade.

METHODS AND RESULTS

This review suggests a new therapeutic strategy for Pso treatment, emphasizing the intricate relationships between small molecules and important signaling pathways involved in the pathophysiology of skin conditions. Improving treatment outcomes and reducing the side effects associated with conventional medicines, this review aims to better understand how tailored small-molecule inhibitors might efficiently control these pathways. This creative approach promotes the creation of individualized treatment plans that can greatly enhance the quality of life of patients with Psoby utilizing the knowledge gathered from recent developments in signaling pathway research.

CONCLUSION

This review delves into the molecular mechanisms underlying Pso and explores how small molecules can be harnessed to enhance treatment outcomes, presenting a new paradigm for managing this chronic skin disorder.

Artemisinin analogues are effective in the treatment of psoriasis by targeting RORγt

Psoriasis is a chronic inflammatory skin autoimmune disease. Th17 cells, when pathologically activated, significantly contribute to the progression of psoriasis. The symptoms of this skin condition could be notably alleviated by targeting and suppressing the activity of these cells. Retinoic acid receptor-associated orphan nuclear hormone receptor γ-t (RORγt), a critical transcription factor in Th17 cells, emerges as a promising therapeutic target for autoimmune conditions which are mediated by the dysregulation of these cells. In this study, we designed and synthesised a series of artemisinin analogues based on the chemical structure of artemisinin, and screened 3 compounds, QHS-1, QHS-2, and QHS-3, with better inhibition efficiency of RORγt activity. We found that each of the three artemisinin analogues were demonstrated efficacy in curbing IMQ-induced skin inflammation and the abnormal proliferation of keratinocytes within the BALB/c mouse model of psoriasis. Our findings indicate that the three artemisinin analogues not only effectively mitigated skin inflammation and the abnormal proliferation of keratinocytes in the IMQ-induced psoriasis model of BALB/c mice but also curtailed the infiltration of immune cells and the production of pro-inflammatory cytokines in the dermis. Furthermore, these compounds modulated the cytokine expression profiles within Th17 cells. They exerted a suppressive effect on the activity of Th17 cells by targeting RORγt, thereby dampening the inflammatory response in the dorsal skin of the mice. This inhibition led to a reduction in the pathological proliferation of keratinocytes. In conclusion, our research underscores the promising therapeutic potential of artemisinin analogues in the treatment of psoriasis, offering a slate of candidate compounds which could pave the way for novel drug development in this field.

Identification of potential biomarkers and therapeutic targets in psoriasis based on NF-κB pathway-related genes

Psoriasis, a common chronic and relapsing inflammatory skin disease, requires the identification of new potential biomarkers to improve its diagnosis and treatment. Dysregulation of the Nuclear factor kappa B (NF-κB) signaling pathway is a hallmark of chronic inflammatory diseases. Accordingly, this study aims to identify NF-κB-related biomarkers for psoriasis diagnosis and treatment. Psoriasis-related datasets were downloaded from the Gene Expression Omnibus to screen for differentially expressed genes (DEGs). The intersection of DEGs with NF-κB-related genes yielded NF-κB_DEGs. A protein-protein interaction network was constructed for NF-κB_DEGs, and hub genes were identified using the MCODE plugin. Through LASSO regression, NF-κB-related characteristic genes for psoriasis were identified and a diagnostic model was developed. This model was validated using the GSE13355 and GSE30999 datasets. Disparities in immune cell infiltration between control and psoriasis groups were assessed via single-sample gene set enrichment analysis. Lastly, we predicted functionally similar genes, related pathways, transcription factors (TFs), microRNAs (miRNAs), and potential therapeutic drugs for the characteristic genes. We uncovered four NF-κB-associated genes-LYN, MALT1, MYD88, and PTGS2-that hold significant diagnostic value for psoriasis. A diagnostic model leveraging these genes exhibited high reliability and effectiveness in both training and validation datasets. Immune profiling revealed marked differences between psoriasis and control groups, with substantial enrichment of dendritic cells (DCs), macrophages, B cells, and T cells in psoriasis samples. We also identified 20 genes functionally related to our characteristic genes, which were primarily involved in pathways such as IκB kinase/NF-κB signaling and Toll-like receptor signaling. Furthermore, we predicted 70 TFs (including SP1, FOS, and JUN) and 17 miRNAs (including hsa-let-7b, hsa-miR-30a, and hsa-miR-155) associated with these genes. Among potential therapeutic candidates, Quercetin emerged as the most promising, scoring highest in our comprehensive evaluation. Our study identified four potential biomarkers-LYN, MALT1, MYD88, and PTGS2-which hold considerable value for the diagnosis and therapy of psoriasis.

Therapeutic Advancements in Psoriasis and Psoriatic Arthritis

Background: Within the past few years, many new therapies have emerged for psoriasis and psoriatic arthritis (PsA). Current topical therapies-including corticosteroids, vitamin D analogs, tapinarof, and roflumilast-remain the mainstay for mild disease, while oral systemic and biologic options are for moderate to severe cases. Biologics-such as Tumor necrosis factor-alpha (TNF-alpha), Interleukin 12/23 (IL-12/23), Interleukin-17 (IL-17), and Interleukin-23 (IL-23)-have revolutionized care by providing highly effective and safer alternatives. Oral small molecules, including Janus kinase (JAK) and tyrosine kinase 2 (TYK2) inhibitors, further expand the therapeutic options. Objectives: The goal for this review article was to examine current and latest treatments for psoriasis and PsA and discuss whether these emerging therapeutic options address the unmet needs of current treatments. Methods: The search for this review article included PubMed, Google Scholar, and ClinicalTrials.gov for relevant articles and current clinical trials using keywords. Results: A wide range of novel psoriatic and PsA therapies are currently undergoing clinical trials. These include selective JAK inhibitors, TYK2 inhibitors, retinoic acid-related orphan receptor (RORγT) inhibitors, oral IL-23 receptor inhibitors, oral IL-17A inhibitors, nanobody products, sphingosine-1-phosphate (S1P1R) antagonists, A3 adenosine receptor (A3AR) agonists, heat shock protein (HSP) 90 inhibitors, and rho-associated protein kinases (ROCK-2) inhibitors. Conclusions: These different mechanisms of action not only expand treatment options but may offer potential solutions for patients who do not achieve adequate response with existing therapies. However, the safety and contraindications of these newer agents remain an important consideration to ensure appropriate patient selection and minimize potential risks. Certain mechanisms may pose increased risks for infection, cardiovascular manifestations, malignancy, or other immune-related adverse events, necessitating careful monitoring and individualized treatment decisions. Ongoing clinical research aims to address unmet needs for patients who do not respond to previous agents to achieve sustained remission, monitor long-term safety outcomes, and assess patient preferences for delivery, including a preference for oral delivery. Oral IL-23 inhibitors hold potential due to their robust safety profiles. In contrast, oral IL-17 inhibitors and TYK-2 inhibitors are effective but may present side effects that could impact their acceptability. It is essential to balance efficacy, safety, and patient preferences to guide the selection of appropriate therapies.

A Snapshot of Biomarkers in Psoriasis

A persistent long-standing, inflammatory skin condition that is brought on by a variety of factors is psoriasis. It is distinguished by itchy, scaly, reddish plaques, particularly on areas of the body that are frequently chafed, including the extensor sites of the limbs. Recent developments in molecular-targeted therapy that use biologics or small-molecule inhibitors can effectively cure even the worst psoriatic indications. The outstanding clinical outcomes of treatment help to clarify the disease's detrimental consequences on quality of life. Biomarkers that identify deep remission are essential for developing uniform treatment plans. Blood protein markers such as AMPs that are consistently quantifiable can be very helpful in routine clinical practice. The metabolic pathways involve biomarkers that can not only help diagnose psoriasis in a clinical setting but also indicate its severity based on the levels present in the body. Machine learning and AI have made a diagnosis of the expression of genes as biomarkers more accessible. In this article, biomarkers, as well as their key role in psoriasis, are discussed.

Investigating the Origin of Epimerization Attenuation during Pd-Catalyzed Cross-Coupling Reactions

Palladium-catalyzed cross-couplings remain among the most robust methodologies to form carbon-carbon and carbon-heteroatom bonds. In particular, carbon-nitrogen (C-N) couplings (Buchwald-Hartwig aminations) find widespread use in fine chemicals industries. The use of base in these reactions is critical for catalyst activation and proton sequestration. Base selection also plays an important role in process design, as strongly basic conditions can impact sensitive stereocenters and result in erosion of stereochemical purity. Herein we investigate the role of a Pd catalyst in suppressing base-mediated epimerization of a sultam stereocenter during a C-N cross-coupling reaction to access the RORγ inhibitor GDC-0022. Online high-performance liquid chromatography-mass spectrometry (HPLC-MS) was employed to acquire reaction time course profiles and to delineate epimerization behavior, identify decomposition pathways, and monitor Pd-containing species. Our ability to monitor organopalladium complexes in real time by HPLC-MS provided strong evidence that the degree of epimerization was correlated to the Pd speciation in solution. Specifically, Pd(II) complexes were associated with mitigating epimerization of six-membered sultams. Additional studies showed that the suppression of epimerization in the presence of Pd(II) can impact Pd-catalyzed reactions of other substrates such as enolizable ketones, thus providing practical insight on the execution and optimization of such processes.

GRP78 Downregulation in Keratinocytes Promotes Skin Inflammation through the Recruitment and Activation of CCR6+ IL-17A-Producing γδ T Cells

The migration of γδ T lymphocytes toward skin lesions and their concomitant pathogenic IL-17A production play a crucial role in the pathogenesis of psoriasis. However, the regulatory mechanisms of IL-17A production by γδ T cells and their migration remain to be fully explored. Intracellular GRP78 is a molecular chaperone that regulates endoplasmic reticulum stress, whereas secretory GRP78, as a member of the resolution-associated molecular patterns, exerts immunoregulatory effects. In this study, we reported that both the intracellular GRP78 in skin lesions and secretory GRP78 in the serum were significantly decreased in patients with psoriasis. A GRP78 knockdown exacerbated imiquimod-induced skin inflammation, whereas the application of recombinant GRP78 protein or BIP inducer X (a GRP78 inducer) attenuated the dermatitis. Mechanistically, the GRP78 knockdown in keratinocytes enhanced the production of chemokines, specifically CCL20, which regulates γδ T-cell migration. Moreover, recombinant GRP78 was found to directly bind to γδ T cells to suppress its migration ability and proinflammatory capacities by downregulating the CCR6 and IL-17A expression. Collectively, our results uncovered a pivotal role of GRP78 in the pathogenesis of psoriasis, which was mainly exerted by regulating the interaction between keratinocytes and γδ T cells, and might provide a promising target for psoriasis therapy.

Novel pharmacotherapies and breakthroughs in psoriasis treatment: 2024 and beyond

INTRODUCTION

The use of the current available therapies for psoriasis management may sometimes be limited by reduced patients' compliance, safety issues for patients' comorbidities, primary lack of efficacy, loss of effectiveness, development of side effects. In this context, several clinical trials investigating the use of both topical and systemic therapies are ongoing, and other new drugs will be approved soon.

AREAS COVERED

The aim of this manuscript is to review current literature and to provide an overview of the current and future trends in psoriasis treatment. A comprehensive review of the English-language medical literature was performed using Pubmed and clinicaltrials.gov databases.

EXPERT OPINION

Although several therapies are currently available for psoriasis' treatment, unmet needs still exist for patients with moderate and severe psoriasis and hence expanding the therapeutic armamentarium is desirable for a more personalized approach. The ongoing development of innovative therapies could provide effective and safe therapies in the future enhancing the therapeutic management of moderate-severe unresponsive psoriasis.

Therapeutic Potential of Targeting the JAK/STAT Pathway in Psoriasis: Focus on TYK2 Inhibition

Psoriasis is an inflammatory skin disease with a chronic relapsing course and an often-detrimental impact on patients' quality of life. Thanks to incredible advances in research over the past few decades, the therapeutic armamentarium of psoriasis is now reasonably broad and structured, with several therapeutic agents that have demonstrated successful long-term control of this condition. However, there are still unfulfilled gaps resulting from the inherent limitations of existing therapies, which have paved the way for the identification of new therapeutic strategies or the improvement of existing ones. A great deal of attention has recently been paid to the JAK/STAT pathway, playing a crucial role in chronic inflammatory skin diseases, including psoriasis. Indeed, in a disease with such a complex pathogenesis, the possibility to antagonize multiple molecular pathways via JAK/STAT inhibition offers an undeniable therapeutic advantage. However, data from clinical trials evaluating the use of oral JAK inhibitors in immune-mediated disorders, such as RA, have arisen safety concerns, suggesting a potentially increased risk of class-specific AEs such as infections, venous thromboembolism, and malignancies. New molecules are currently under investigation for the treatment of psoriasis, such as deucravacitinib, an oral selective inhibitor that binds to the regulatory domain of TYK2, brepocitinib (PF-06700841) and PF-06826647 that bind to the active site in the catalytic domain. Due to the selective TYK2 blockade allowing the inhibition of key cytokine-mediated signals, such as those induced by IL-12 and IL-23, anti-TYK2 agents appear to be very promising as the safety profile seems to be superior compared with pan-JAK inhibitors. The aim of our review is to thoroughly explore the rationale behind the usage of JAK inhibitors in PsO, their efficacy and safety profiles, with a special focus on oral TYK2 inhibitors, as well as to provide a forward-looking update on novel therapeutic strategies targeting the TYK2 pathway in psoriasis.

Functional Genomics and Insights into the Pathogenesis and Treatment of Psoriasis

Psoriasis is a lifelong, systemic, immune mediated inflammatory skin condition, affecting 1-3% of the world's population, with an impact on quality of life similar to diseases like cancer or diabetes. Genetics are the single largest risk factor in psoriasis, with Genome-Wide Association (GWAS) studies showing that many psoriasis risk genes lie along the IL-23/Th17 axis. Potential psoriasis risk genes determined through GWAS can be annotated and characterised using functional genomics, allowing the identification of novel drug targets and the repurposing of existing drugs. This review is focused on the IL-23/Th17 axis, providing an insight into key cell types, cytokines, and intracellular signaling pathways involved. This includes examination of currently available biological treatments, time to relapse post drug withdrawal, and rates of primary/secondary drug failure, showing the need for greater understanding of the underlying genetic mechanisms of psoriasis and how they can impact treatment. This could allow for patient stratification towards the treatment most likely to reduce the burden of disease for the longest period possible.

Small Molecules in the Management of Psoriasis and Psoriatic Arthritis

Psoriasis is a common chronic, immune-mediated inflammatory skin disease associated with various comorbidities. Managing psoriasis is often challenging as the therapy is decided based on the area of the disease, associated comorbidities and impairment in quality of life, besides the patient's preference. Making progress in the development of new molecules that can be used topically or orally, effectively controlling the disease with minimal side effects and providing long-lasting remissions are the needs of the hour. Recent developments in understanding the complexities of the pathogenesis of psoriasis have resulted in the reinforcement of treatment modalities, leading to the evolution of various biologics and small-molecule inhibitors. In comparison with biologics, both patients and treating physicians prefer small molecules for various reasons such as avoiding injections and side effects that are associated with biologics biologics. Moreover small molecules are economical than biologics. Newer small molecules, both topical and oral, are promising additions to the therapeutic arsenal in the management of psoriasis in the future.

Association of IL-17F rs763780 polymorphism and risk of psoriasis in Turkish population: a case-control study

BACKGROUND

Psoriasis represents a chronic inflammatory phenotype shaped by genetic interactions, characterized by keratinocyte hyperproliferation and commonly affecting the skin and joints. Experimental and clinical studies suggest that the IL-17F gene locus plays a role as a central cytokine in the immunopathogenesis of psoriasis.

OBJECTIVES

Based on the central role of IL-17F in the pathogenesis of psoriasis, the authors thought that variations in this gene could affect the susceptibility and severity of this disease. Therefore, in this study, the authors aimed to analyze whether the IL-17F rs763780 variant has an effect on psoriasis pathogenesis in the Turkish population.

METHOD

In this case-control study, the study group consisted of 603 people (201 psoriasis patients (73 males/128 females)/402 controls (146 males/256 females) were genotyped in terms of IL-17F rs763780 polymorphism with TaqMan 5' Allelic Discrimination Test.

RESULTS

The genotype distributions of the IL-17F rs763780 polymorphism between patients and control groups were statistically different, and the TC (heterozygous genotype) and CC (homozygous mutant genotype) genotypes were more represented in the patients group than in the control group (24.9% vs. 10.2%; 2.0% vs. 0.2%, respectively). In addition, the variant C allele was higher in the patients group and this was statistically significant (p < 0.001), and the C allele carriage was associated with a 3.14-fold increased risk of psoriasis (95% CI 2.015‒24.921).

STUDY LIMITATIONS

The present study has some limitations. The first limitation is the relatively small sample size. The second limitation is that the authors could not measure IL-17F expression levels. However, the present study data draw attention to the importance of IL-17F which deserves to be studied in a larger sample group.

CONCLUSION

We report that IL-17F rs763780 TC and CC genotype and C allele are associated with an increased risk of psoriasis in the Turkish population.

New and Emerging Oral/Topical Small-Molecule Treatments for Psoriasis

The introduction of biologic therapies has led to dramatic improvements in the management of moderate-to-severe psoriasis. Even though the efficacy and safety of the newer biologic agents are difficult to match, oral administration is considered an important advantage by many patients. Current research is focused on the development of oral therapies with improved efficacy and safety compared with available alternatives, as exemplified by deucravacitinib, the first oral allosteric Tyk2 inhibitor approved for the treatment of moderate to severe psoriasis in adults. Recent advances in our knowledge of psoriasis pathogenesis have also led to the development of targeted topical molecules, mostly focused on intracellular signaling pathways such as AhR, PDE-4, and Jak-STAT. Tapinarof (an AhR modulator) and roflumilast (a PDE-4 inhibitor) have exhibited favorable efficacy and safety outcomes and have been approved by the FDA for the topical treatment of plaque psoriasis. This revision focuses on the most recent oral and topical therapies available for psoriasis, especially those that are currently under evaluation and development for the treatment of psoriasis.

Volatile Oil Containing Plants as Phytopharmaceuticals to Treat Psoriasis: A Review

INTRODUCTION

Psoriasis is a chronic skin condition caused by an autoimmune response that accelerates the life cycle of skin cells, resulting in the characteristic symptoms of scaling, inflammation, and itching.

METHODS

Palliative treatment options for psoriasis often prioritize the use of volatile oils. These oils contain monoterpenes, sesquiterpenes, and phenylpropanoids that are intricately linked to the molecular cascades involved in the pathogenesis and symptoms of psoriasis. To evaluate the antipsoriatic efficacy of volatile oils and their components, we conducted a systematic review of scientific studies. Our literature search encompassed various online databases, including PubMed, BIREME, SCIELO, Open Grey, Scopus, and ScienceDirect. The selected studies included experimental in vitro/in vivo assessments as well as clinical studies that examined the potential of volatile oils and their extracts as antipsoriatic agents. We excluded conference proceedings, case reports, editorials, and abstracts. Ultimately, we identified and evaluated a total of 12 studies for inclusion in our analysis.

RESULTS

The data collected, compiled, and analyzed strongly support the interaction between volatile oils and their constituents with the key molecular pathways involved in the pathogenesis of psoriasis and the development of its symptoms. Volatile oils play a significant role in the palliative treatment of psoriasis, while their chemical constituents have the potential to reduce the symptoms and recurrence of this condition.

CONCLUSION

The current review highlights that the constituents found in volatile oils offer distinct chemical frameworks that can be regarded as promising starting points for the exploration and development of innovative antipsoriatic agents.

Signaling pathways and targeted therapies for psoriasis

Psoriasis is a common, chronic, and inflammatory skin disease with a high burden on individuals, health systems, and society worldwide. With the immunological pathologies and pathogenesis of psoriasis becoming gradually revealed, the therapeutic approaches for this disease have gained revolutionary progress. Nevertheless, the mechanisms of less common forms of psoriasis remain elusive. Furthermore, severe adverse effects and the recurrence of disease upon treatment cessation should be noted and addressed during the treatment, which, however, has been rarely explored with the integration of preliminary findings. Therefore, it is crucial to have a comprehensive understanding of the mechanisms behind psoriasis pathogenesis, which might offer new insights for research and lead to more substantive progress in therapeutic approaches and expand clinical options for psoriasis treatment. In this review, we looked to briefly introduce the epidemiology, clinical subtypes, pathophysiology, and comorbidities of psoriasis and systematically discuss the signaling pathways involving extracellular cytokines and intracellular transmission, as well as the cross-talk between them. In the discussion, we also paid more attention to the potential metabolic and epigenetic mechanisms of psoriasis and the molecular mechanistic cascades related to its comorbidities. This review also outlined current treatment for psoriasis, especially targeted therapies and novel therapeutic strategies, as well as the potential mechanism of disease recurrence.

Challenges and Future Trends in the Treatment of Psoriasis

Psoriasis is a chronic inflammatory skin disorder, and current treatments include topical therapies, phototherapy, systemic immune modulators, and biologics, aiming to alleviate symptoms and improve quality of life. However, challenges persist, such as adverse effects, treatment resistance, high costs, and variability in response among individuals. The future of psoriasis treatment shows promising emerging trends. New biologic agents targeting novel pathways, such as interleukin 23 inhibitors like mirikizumab, offer enhanced efficacy. Small molecule inhibitors like RORγt inhibitors and ROCK2 inhibitors provide additional treatment options. Combination therapies, including biologics with methotrexate, may improve treatment response. Advancements in topical treatments utilizing microneedles and nanoparticle-based carriers can enhance drug delivery and improve therapeutic outcomes. Biomarkers and multi-omics technologies hold potential for personalized treatment approaches, thus aiding in diagnosis, predicting treatment response, and guiding therapeutic decisions. Collaboration among researchers, clinicians, and industry stakeholders is crucial to translating these scientific breakthroughs into clinical practice. By addressing current challenges and exploring these promising trends, we can optimize psoriasis management and improve the lives of those affected by this chronic condition.

Small molecule inhibitors of RORγt for Th17 regulation in inflammatory and autoimmune diseases

As a ligand-dependent transcription factor, retinoid-associated orphan receptor γt (RORγt) that controls T helper (Th) 17 cell differentiation and interleukin (IL)-17 expression plays a critical role in the progression of several inflammatory and autoimmune conditions. An emerging novel approach to the therapy of these diseases thus involves controlling the transcriptional capacity of RORγt to decrease Th17 cell development and IL-17 production. Several RORγt inhibitors including both antagonists and inverse agonists have been discovered to regulate the transcriptional activity of RORγt by binding to orthosteric- or allosteric-binding sites in the ligand-binding domain. Some of small-molecule inhibitors have entered clinical evaluations. Therefore, in current review, the role of RORγt in Th17 regulation and Th17-related inflammatory and autoimmune diseases was highlighted. Notably, the recently developed RORγt inhibitors were summarized, with an emphasis on their optimization from lead compounds, efficacy, toxicity, mechanisms of action, and clinical trials. The limitations of current development in this area were also discussed to facilitate future research.

Molecular treatment trajectories within psoriatic T lymphocytes: a mini review

Multiple biological processes in mammalian cells are implicated in psoriasis (Ps) development and progression, as well as in the pathogenic mechanisms associated with this chronic immune-mediated inflammatory disease (IMID). These refer to molecular cascades contributing to the pathological topical and systemic reactions in Ps, where local skin-resident cells derived from peripheral blood and skin-infiltrating cells originating from the circulatory system, in particular T lymphocytes (T cells), are key actors. The interplay between molecular components of T cell signalling transduction and their involvement in cellular cascades (i.e. throughout Ca2+/CaN/NFAT, MAPK/JNK, PI3K/Akt/mTOR, JAK/STAT pathways) has been of concern in the last few years; this is still less characterised than expected, even though some evidence has accumulated to date identifying them as potential objects in the management of Ps. Innovative therapeutic strategies for the use of compounds such as synthetic Small Molecule Drugs (SMDs) and their various combinations proved to be promising tools for the treatment of Ps via incomplete blocking, also known as modulation of disease-associated molecular tracks. Despite recent drug development having mainly centred on biological therapies for Ps, yet displaying serious limitations, SMDs acting on specific pathway factor isoforms or single effectors within T cell, could represent a valid innovation in real-world treatment patterns in patients with Ps. Of note, due to the intricate crosstalk between intracellular pathways, the use of selective agents targeting proper tracks is, in our opinion, a challenge for modern science regarding the prevention of disease at its onset and also in the prediction of patient response to Ps treatment.

Psoriasis: A Primer for General Physicians

Psoriasis is a multisystem, polygenic, inflammatory condition that typically causes changes in the skin. Although there is a significant genetic component, environmental factors like infections can have a significant impact on triggering the disease. A major part of the pathogenesis of psoriasis is played by the Interleukin (IL) IL23/IL17 axis along with the immune-related cells mainly macrophages and dendritic cells (DCs). Additionally, the role of various cytokines along with the toll-like receptors has also been pointed out in immunopathogenesis. These have been supported by the efficacy of biological therapies including TNF alpha inhibitors and inhibitors of IL17 and IL23. We have summarized the topical as well as systemic therapies for psoriasis including biologics. The article throws light on a few emerging therapeutic options like modulators of sphingosine 1-phosphate receptor 1 and Rho-associated kinase 2 inhibitors.

Perspective insights of small molecules, phytoconstituents and biologics in the management of psoriasis: A focus on targeting major inflammatory cytokine pathways

Psoriasis is an enduring, pruritic and papulosquamous skin ailment that poses a significant burden on public health. It is mainly characterized by hyperkeratosis, acanthosis, parakeratosis, scaly and erythematous plaques. Biomarkers like interleukin-17, interleukin-12 and -23 and tumor necrosis factor-α serve as key drivers of psoriatic pathogenesis. Triggered release of pro-inflammatory cytokines from various up-regulated pathways leads to psoriatic inflammation. Several target moieties like biologics, small molecules and herbal moieties play a fundamental role in the repression of pathogenesis of psoriasis. Biologics and small molecules engaged in the management of psoriasis have been emphasized in detail. An insight into nano-carrier interventions on herbal moieties and clinical aspects of psoriasis are also highlighted. This review emphasizes various pathological targets involved in psoriasis.

Traditional uses, phytochemistry, pharmacology, and toxicity of Eriobotrya japonica leaves: A summary

ETHNOPHARMACOLOGICAL RELEVANCE

Eriobotrya japonica Lindl. has been included in "The Plant List" (http://www.theplantlist.org) and is the most widely researched species in its genus. E. japonica is a subtropical evergreen fruit tree belonging to the Rosaceae family. Its dried leaves are widely used in traditional Chinese herbal medicine to treat coughing caused by pulmonary inflammation, dyspnea due to asthma and cough, nausea caused by stomach disorders, restlessness, and thirst. Furthermore, it is used to treat stomach ache, ulcers, chronic bronchitis, cancer, and diabetes mellitus in Japanese folk medicine. However, no systematic reports on E. japonica leaves have been published before.

AIM OF THE STUDY

This review summarizes the available information on the traditional uses, phytochemistry, pharmacology, toxicity, and quality control of various extracts and phytoconstituents of E. japonica leaves.

MATERIALS AND METHODS

Relevant publications between 1931 and 2022 were considered. Chinese and English studies on E. japonica leaves were collected from databases, including PubMed, Web of Science, Elsevier, ACS Publications, Springer, and CNKI (Chinese). The traditional uses, phytochemistry, pharmacology, toxicity, and quality control of E. japonica leaves were reviewed.

RESULTS

Briefly, 164 compounds, including triterpenes, flavonoids, sesquiterpene glycosides, megastigmane derivatives, phenylpropanoids, and organic acids, have been identified from E. japonica leaves, in addition to 169 volatile oils. More than half of these compounds have not yet been reported to have pharmacological activities. Triterpenes and flavonoids are the most important bioactive compounds responsible for pharmacological activities, such as antidiabetic, anti-inflammatory, and antitumor activities. Other beneficial physiological effects such as antioxidant, hepatoprotective, bronchodilatory, antitussive, and expectorant effects and tracheal smooth muscle relaxation, protection against myocardial ischemia injury, and improved cognitive activities have also been reported. High doses of E. japonica leaf extracts have been used in laboratory animals, and no side effects or toxicity-symptoms have been observed.

CONCLUSIONS

The pharmacological activities of E. japonica leaves support their use in traditional Chinese herbal medicine. However, several aspects, such as the bioavailability, pharmacodynamics, pharmacokinetics, mechanism of action, and structure-activity relationships of the pure compounds isolated from E. japonica leaves, have not been studied yet and warrant further studies.

Delivery and diffusion of retinal in dermis and epidermis through the combination of prodrug nanoparticles and detachable dissolvable microneedles

To minimize chemical degradation of retinal, we graft this aldehyde on chitosan chains to make them self-assemble into pro-retinal nanoparticles (PRNs), which we then load into detachable dissolvable microneedles (DDMNs) made of 1:1 (by weight) hyaluronic acid/maltose. The presence of PRNs in the hyaluronic acid-maltose needle matrix also helps improve the microneedles' mechanical strength. Ex vivo administration of PRN-loaded DDMNs on fresh porcine ear skin shows, as observed by stereomicroscopic and confocal fluorescence microscopic analyses of the cross-sectioned tissue pieces, complete deposition followed by dissolution of the needles and diffusion of the PRNs in epidermis and dermis. Rats administered with a single dose of PRN-loaded DDMNs show significantly increased epidermal thickness as compared to rats administered with control DDMNs (no PRN). Both the PRN-loaded DDMNs and the control DDMNs produce no skin irritation in rats.

Treatments for psoriasis: A journey from classical to advanced therapies. How far have we reached?

Psoriasis is considered an autoimmune, inflammatory disorder with a genetic basis. The underlying aetiology is yet unclear. Evidence suggests the congregation of immune cells and their secreted inflammatory cytokines, leukocytes, and other inflammation-promoting factors in large amounts within the epidermal layers of the skin, driving an inflammatory milieu. Although psoriasis is not a fatal condition, patients experience severe pain and suffering. It has a debilitating effect on the physiological and psychological state of the patient. Its distinguishing features are inflammation, formation of plaques on the skin and hyperproliferation of keratinocytes. Therapeutic strategies for treating psoriasis witnessed a radical improvement from traditional therapies to the approval of specific therapies like biologics and small molecules. The emerging evidence about new pharmacological targets and mechanisms in psoriasis has widened the scope for expanding therapeutic strategies. Our review discusses the existing treatments for plaque psoriasis and updates on therapies based on novel pharmacological targets in clinical development.

Potential effects and mechanisms of Chinese herbal medicine in the treatment of psoriasis

ETHNOPHARMACOLOGICAL RELEVANCE

Psoriasis is a chronic inflammatory dermatosis related to high morbidity and mortality. The incidence of psoriasis is increasing in recent decades. Some patients with psoriasis are anxious about the underlying side effects of synthetic drugs they are on. Therefore, they are eager to seek alternative and efficient therapy, such as Chinese herbal medicine (CHM). Researchers have found some CHM provides best source for the development of anti-psoriatic drugs because of their structural diversity and fewer adverse reactions. Some of CHM formulas or active constituents extracted from CHM have been rapidly developed into clinical drugs with good efficacy. At present, along with the CHM formulas, single CHM and its active components have been extensively accepted and utilized in the treatment of psoriasis, whose therapeutic mechanisms hitherto have not been thoroughly illustrated.

AIM OF THE STUDY

This review aimed to comprehensively summarize about the existing therapeutic mechanisms of CHM in the treatment of psoriasis and to provide a reference to develop future related studies in this field.

MATERIALS AND METHODS

Relevant literatures about how CHM treated psoriasis were acquired from published scientific studies (including PubMed, CNKI, Web of Science, Baidu Scholar, The Plant List, Elsevier and SciFinder). All plants appearing in the review have been included in The Plant List or Medicinal Plant Names Services (MPNS).

RESULTS

In this review, we collect numerous literatures about how CHM treats psoriasis via immune cells, signaling pathways and disease-related mediators and systematically elucidates potential mechanisms from the point of the suppression of oxidative stress, the inhibition of abnormal abnormal proliferation and differentiation, the inhibition of immune responses, and the suppression of angiogenesis.

CONCLUSIONS

Psoriasis is considered as a complicated disease caused by interaction among various mechanisms. The CHM formulas, single CHM and its active components have considerable positive reports about the treatment of psoriasis, which brings hope for a promising future of CHM in the clinical therapy of psoriasis. In the paper, we have concluded that the existing therapeutic mechanisms of CHM in the treatment of psoriasis.

Vitamin D Signaling in Psoriasis: Pathogenesis and Therapy

Psoriasis is a systemic, chronic, immune-mediated disease that affects approximately 2-3% of the world's population. The etiology and pathophysiology of psoriasis are still unknown, but the activation of the adaptive immune system with the main role of T-cells is key in psoriasis pathogenesis. The modulation of the local neuroendocrine system with the downregulation of pro-inflammatory and the upregulation of anti-inflammatory messengers represent a promising adjuvant treatment in psoriasis therapies. Vitamin D receptors and vitamin D-mediated signaling pathways function in the skin and are essential in maintaining the skin homeostasis. The active forms of vitamin D act as powerful immunomodulators of clinical response in psoriatic patients and represent the effective and safe adjuvant treatments for psoriasis, even when high doses of vitamin D are administered. The phototherapy of psoriasis, especially UVB-based, changes the serum level of 25(OH)D, but the correlation of 25(OH)D changes and psoriasis improvement need more clinical trials, since contradictory data have been published. Vitamin D derivatives can improve the efficacy of psoriasis phototherapy without inducing adverse side effects. The anti-psoriatic treatment could include non-calcemic CYP11A1-derived vitamin D hydroxyderivatives that would act on the VDR or as inverse agonists on RORs or activate alternative nuclear receptors including AhR and LXRs. In conclusion, vitamin D signaling can play an important role in the natural history of psoriasis. Selective targeting of proper nuclear receptors could represent potential treatment options in psoriasis.

Chinese herbal medicine Jia Wei Jing Xie Yin (JWJXY) ameliorates psoriasis via suppressing the Th17 cell response

Background

Psoriasis is a chronic autoimmune disease. At present, it is very difficult to treat; however, clinical trials have shown that the traditional Chinese medicine (TCM) treatment of psoriasis has certain advantages. The Chinese herbal medicine Jia Wei Jing Xie Yin (JWJXY) has its origins in Jing Xie Yin, a medicine created by the TCM doctor Wu Jun. Previous studies have shown that JWJXY has good clinical efficacy for patients with blood-heat type psoriasis, but its mechanism is unknown.

Methods

This paper aimed to further study the therapeutic effect and mechanism of JWJXY on an imiquimod (IMQ)-induced, psoriasis-like mouse model (0.4 mL, i.g., 6 days). The histopathological skin changes were observed by hematoxylin and eosin (HE) staining, the infiltration of cluster of differentiation 11B (CD11b) and cluster of differentiation 4 (CD4) cells was observed by immunohistochemistry, lymphocyte subsets were detected by flow cytometry, T helper (Th)17 cell expression was perceived by flow cytometry, and Th17 cell-related gene expression was detected by real-time quantitative polymerase chain reaction (qPCR).

Results

JWJXY significantly reduced the skin thickness of the IMQ-induced model mouse. Compared with that in the vehicle group, the skin tissue of the mice in the JWJXY group showed significantly reduced infiltration of CD11b⁺ and CD4⁺ T cells. Flow cytometry results showed that JWJXY decreased the proportion of B220 and Th17 cells in the spleen tissue of the mice. There was no significant effect on the proportion of Th1 or regulatory T cells (Treg) cells. Compared with that in the vehicle group, the skin tissue of the mice in the JWJXY group showed significantly decreased expression of interleukin-17A (IL-17A), IL-17F, retinoic acid receptor-related orphan receptor gamma t (RORγt), IL-1β, interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) messenger RNA (mRNA).

Conclusions

The study confirmed the therapeutic effect of JWJXY on psoriasis. Its mechanism of action might be to inhibit the Th17 cell response but not the Th1 and Treg response.

Novel Therapeutic Target(s) for Psoriatic Disease

Psoriasis and psoriatic arthritis, together known as psoriatic disease, is highly prevalent chronic relapsing inflammatory disease affecting skin, joints or both and is associated with several comorbidities such as cardiovascular, metabolic, psychiatric, renal disease etc. The etiopathogenesis of psoriasis is complex and mainly driven by aberrant immune response owing to the genetic susceptibility and various environmental factors such as trauma, infections and drugs. Recent advances in understanding molecular and cellular pathways have identified tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-23, IL-22 as major contributors in psoriasis pathogenesis. Advances in the knowledge of pathophysiology, the interaction of autoinflammation and clinical phenotypes have led to the development of highly effective targeted therapeutic agents which include TNF-α, IL-17, IL-23, IL-1 α/β or IL-36 inhibitors or receptor blockers, small molecule drugs like phosphodiesterase-4 inhibitors (apremilast), Janus kinase (JAK) inhibitors, retinoic acid receptor-related orphan receptor γt (RORγt) inhibitors. These novel drugs have promised the potential of improved disease control. In recent years, the transition from biologics to biosimilars especially with TNF-α inhibitors had significant impact on decreasing health care cost and increasing therapeutic options to the patients. However, selection of right treatment for an individual patient still remains challenging. Moreover, interplay between different epigenetic mechanisms such as the DNA methylation, chromatin modifications and noncoding RNA regulation has recently been started to be deciphered. Enzymes inhibitors involved in epigenetic pathways such as DNA methyltransferases and histone deacetylases demonstrated to restore normal epigenetic patterns in clinical settings and have provided the potential as novel therapeutic targets for psoriasis. In this review, we will discuss novel biologic agents and newer therapeutic approaches in treatment of psoriatic disease.

Disturbed expression of vitamin D and retinoic acid-related orphan receptors α and γ and of megalin in inflammatory skin diseases

The pathogenesis of inflammatory skin diseases is associated with the abnormal activity of keratinocytes and immune cells infiltrate. Vitamin D₃ deficiency can correlate with the increased incidence, severity and duration of inflammatory skin disorders. The exact mechanism on how vitamin D₃ influences inflammatory skin diseases still requires clarification. However, it can be associated with the disturbances in transmembrane glycoprotein-LRP2/megalin, which is implicated in vitamin D₃ transport to the cell, and defects in vitamin D-signalling through the nuclear receptors. Therefore, by using immunohistochemistry, we analysed the expression of LRP2/megalin, VDR, RORα and RORγ in allergic contact dermatitis, lichen simplex chronicus, sarcoidosis and psoriasis in comparison with the normal skin. We observed decreased expression of LRP2/megalin in all inflammatory lesions in comparison with the normal skin. Significant differences were also noticed in VDR, RORα and RORγ levels between inflammatory lesions and normal skin. Our research indicates disturbed expression of LRP2/megalin, VDR, RORα and RORγ in inflammatory skin lesions in comparison with normal skin. Therefore, we suggest that changes in the activity of these proteins may play role in pathogenesis of inflammatory skin disorders. Furthermore, we suggest that LRP2/megalin, VDR, RORα and RORy may serve as targets in therapy of these diseases.

Experimental Pharmacological Management of Psoriasis

Psoriasis is a chronic, relapsing, immune-mediated systemic disease. Its pathogenesis is complex and not fully understood yet. Genetic and epigenetic factors interact with molecular pathways involving TNF-α, IL-23/IL-17 axis, and peculiar cytokines, as IL-36 or phosphodiesterase 4. This review discusses the mechanisms involved in the development of the disease, as well as the therapeutic options proposed following the investigation of the inflammatory psoriatic pathways. We performed a comprehensive search using the words “psoriasis” and the newest molecules currently under investigation and approval. From these data, a new scenario in psoriasis is occurring to personalize the therapies - especially systemic ones and those using small molecules – and avoid topical and injectable drugs. We reported the newest therapeutic opportunities, including the inhibitors of Janus kinase/tyrosine kinase 2, phosphodiesterase-4 and IL-36 receptor. Today, more than 20 molecules are under investigation for the treatment of cutaneous psoriasis. Most of them are constituted by small molecules or biologic therapies. This underlines how psoriasis needs systemic therapies, due to its complex pathogenesis and multisystemic involvement.

Therapeutic Development Based on the Immunopathogenic Mechanisms of Psoriasis

Psoriasis, a complex inflammatory autoimmune skin disorder that affects 2–3% of the global population, is thought to be genetically predetermined and induced by environmental and immunological factors. In the past decades, basic and clinical studies have significantly expanded knowledge on the molecular, cellular, and immunological mechanisms underlying the pathogenesis of psoriasis. Based on these pathogenic mechanisms, the current disease model emphasizes the role of aberrant Th1 and Th17 responses. Th1 and Th17 immune responses are regulated by a complex network of different cytokines, including TNF-α, IL-17, and IL-23; signal transduction pathways downstream to the cytokine receptors; and various activated transcription factors, including NF-κB, interferon regulatory factors (IRFs), and signal transducer and activator of transcriptions (STATs). The biologics developed to specifically target the cytokines have achieved a better efficacy and safety for the systemic management of psoriasis compared with traditional treatments. Nevertheless, the current therapeutics can only alleviate the symptoms; there is still no cure for psoriasis. Therefore, the development of more effective, safe, and affordable therapeutics for psoriasis is important. In this review, we discussed the current trend of therapeutic development for psoriasis based on the recent discoveries in the immune modulation of the inflammatory response in psoriasis.

Key Signaling Pathways in Psoriasis: Recent Insights from Antipsoriatic Therapeutics

Psoriasis is a common chronic inflammatory skin disease associated with several comorbidities and reduced quality of life. In the past decades, highly effective targeted therapies have led to breakthroughs in the management of psoriasis, providing important insights into the pathogenesis. This article reviews the current concepts of the pathophysiological pathways and the recent progress in antipsoriatic therapeutics, highlighting key targets, signaling pathways and clinical effects in psoriasis.

Small-molecule modulators of the circadian clock: Pharmacological potentials in circadian-related diseases

Disruption of circadian oscillations has a wide-ranging impact on health, with the potential to induce the development of clock-related diseases. Small-molecule modulators of the circadian clock (SMMCC) target core or noncore clock proteins, modulating physiological effects as a consequence of agonist, inverse agonist, or antagonist interference. These pharmacological modulators are usually identified using chemical screening of large libraries of active compounds. However, target-based screens, chemical optimization, and circadian crystallography have recently assisted in the identification of these compounds. In this review, we focus on established and novel SMMCCs targeting both core and noncore clock proteins, identifying their circadian targets, detailed circadian effects, and specific physiological effects. In addition, we discuss their therapeutic potential for the treatment of diverse clock-related disorders (such as metabolic-associated disorders, autoimmune diseases, mood disorders, and cancer) and as chronotherapeutics. Future perspectives are also considered, such as clinical trials, and potential safety hazards, including those in the absence of clinical trials.

Leflunomide Sustained Skin Delivery Based on Sulfobetaine-Modified Chitosan Nanoparticles Embedded in Biodegradable Polyesters Films

The aim of the present study was to prepare a leflunomide (LFD) sustained release transdermal delivery system for the treatment of psoriasis. In this context, LFD-loaded nanoparticles (NPs) based on either neat chitosan (CS) or CS modified with [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SDAEM, a sulfobetaine zwitterionic compound) were initially prepared via ionotropic gelation and characterized in terms of in vitro dissolution, physicochemical, and antibacterial properties. Results showed that the use of the SDAEM-modified CS resulted in the formation of LFD-loaded NPs with improved wetting and solubilization properties, better in vitro dissolution profile characteristics (i.e., higher dissolution rate and extent), and improved (enhanced) antibacterial properties. The resultant LFD-loaded NPs were then embedded in suitable thin-film skin patches, prepared via spin-coating, utilizing two different biodegradable polyesters, namely methoxy polyethylene glycol-b-poly(L-lactide) (mPEG-b-PLA, at a ratio of 25/75 mPEG to PLA) and poly(lactic-co-glycolic acid) (PLGA at a ratio of 75/25 DL-lactide/glycolide copolymer). Results showed the formation of polymeric thin-films with no agglomeration (or trapped air) and uniform structure in all cases, while the LFD-loaded NPs were successfully embedded in the polymeric matrix. Analysis of the obtained in vitro dissolution profiles revealed a sustained release profile of the drug for up to approximately twelve days, while between the two proposed systems, the use of CS-SDAEM NPs (independently of the polyester type) was the most promising formulation approach.

Resolvin E1 Regulates Th17 Function and T Cell Activation

Resolvin E1 (RvE1) is a specialized pro-resolving lipid mediator derived from eicosapentaenoic acid and plays a critical role in resolving inflammation and tissue homeostasis. T_h17 cells are a distinct group of T helper (T_h) cells with tissue-destructive functions in autoimmune and chronic inflammatory diseases via the secretion of IL-17. Dendritic cell (DC)-mediated antigen presentation regulates the T_h17-induced progression of inflammation and tissue destruction. In this study, we hypothesized that the RvE1 would restore homeostatic balance and inflammation by targeting the T_h17 function. We designed three experiments to investigate the impact of RvE1 on different phases of T_h17 response and the potential role of DCs: First CD4⁺ T cells were induced by IL-6/TGF_β to measure the effect of RvE1 on T_h17 differentiation in an inflammatory milieu. Second, we measured the impact of RvE1 on DC-stimulated T_h17 differentiation in a co-culture model. Third, we measured the effect of RvE1 on DC maturation. RvE1 blocked the CD25, CCR6 and IL-17 expression; IL-17, IL-21, IL-10, and IL-2 production, suggesting inhibition of T cell activation, T_h17 stimulation and chemoattraction. RvE1 also suppressed the activation of DCs by limiting their pro-inflammatory cytokine production. Our findings collectively demonstrated that the RvE1 targeted the T_h17 activation and the DC function as a potential mechanism for inflammatory resolution and acquired immune response.

Differential Gene Expression Patterns in Blood and Cerebrospinal Fluid of Multiple Sclerosis and Neuro-Behçet Disease

Inflammatory demyelinating disorders of the central nervous system are debilitating conditions of the young adult, here we focus on multiple sclerosis (MS) and neuro-Behçet disease (NBD). MS is an autoimmune disorder of the central nervous system. NBD, a neurological manifestation of an idiopathic chronic relapsing multisystem inflammatory disease, the behçet disease. The diagnosis of MS and NBD relies on clinical symptoms, magnetic resonance imaging and laboratory tests. At first onset, clinical and imaging similarities between the two disorders may occur, making differential diagnosis challenging and delaying appropriate management. Aiming to identify additional discriminating biomarker patterns, we measured and compared gene expression of a broad panel of selected genes in blood and cerebrospinal fluid (CSF) cells of patients suffering from NBD, MS and non inflammatory neurological disorders (NIND). To reach this aim, bivariate and multivariate analysis were applied. The Principal Analysis Component (PCA) highlighted distinct profiles between NBD, MS, and controls. Transcription factors foxp3 in the blood along with IL-4, IL-10, and IL-17 expressions were the parameters that are the main contributor to the segregation between MS and NBD clustering. Moreover, parameters related to cellular activation and inflammatory cytokines within the CSF clearly differentiate between the two inflammatory diseases and the controls. We proceeded to ROC analysis in order to identify the most distinctive parameters between both inflammatory neurological disorders. The latter analysis suggested that IL-17, CD73 in the blood as well as IL-1β and IL-10 in the CSF were the most discriminating parameters between MS and NBD. We conclude that combined multi-dimensional analysis in blood and CSF suggests distinct mechanisms governing the pathophysiology of these two neuro-inflammatory disorders.

Therapeutics targeting the IL-23 and IL-17 pathway in psoriasis

Psoriasis is a chronic inflammatory disease characterised by sharply demarcated erythematous and scaly skin lesions accompanied by systemic manifestations. Classified by WHO as one of the most serious non-infectious diseases, psoriasis affects 2-3% of the global population. Mechanistically, psoriatic lesions result from hyperproliferation and disturbed differentiation of epidermal keratinocytes that are provoked by immune mediators of the IL-23 and IL-17 pathway. Translational immunology has had impressive success in understanding and controlling psoriasis. Psoriasis is the first disease to have been successfully treated with therapeutics that directly block the action of the cytokines of this pathway; in fact, therapeutics that specifically target IL-23, IL-17, and IL-17RA are approved for clinical use and show excellent efficacy. Furthermore, inhibitors of IL-23 and IL-17 intracellular signalling, such as TYK2 or RORγt, are in clinical development. Although therapies that target the IL-23 and IL-17 pathway also improve psoriatic arthritis symptoms, their effects on long-term disease modification and psoriasis-associated comorbidities still need to be explored.

Pentacyclic triterpene compounds from loquat leaves reduce skin inflammation and epidermal hyperplasia in psoriasis via inhibiting the Th17 cells

Psoriasis is a refractory inflammatory skin disease affecting 2 %-3 % of the world population, characterized by the infiltration and hyper-proliferation of inflammatory cells and aberrant differentiation of keratinocytes. Targeting the IL-23/ Th17 axis has been well recognized as a promising therapeutic strategy, as the IL-23/ Th17 signal plays a vital role in the pathology of psoriasis. Three pentacyclic triterpene compounds isolated from loquat leaves have been reported with significant inhibitory effects on RORγt transcription activity and Th17 cell differentiation, and excellent performance in preventing lupus nephritis pathogenesis. However, the potential effects of these pentacyclic triterpene compounds on psoriasis remain unknown. In this study, we demonstrated the potent therapeutic effects of these pentacyclic triterpene compounds on psoriasis. These three pentacyclic triterpene compounds significantly alleviated skin inflammation as well as aberrant keratinocyte proliferation in an imiquimod-induced mouse psoriasis model. These compounds also inhibited the infiltration of immune cells and the level of pro-inflammatory cytokine in the dermis, as well as the cells number and changed the cytokine profiling expression of Th17 cells. These compounds could reduce the amount of CD4⁺ and CD8⁺ T cells in local lymph node, but not in spleen, which is different from hydrocortisone, the positive control treatment. These results suggest better performance of these compounds than steroids on treating psoriasis with less side effects on the integrated immune system. In summary, our findings uncover the potent therapeutic effects of pentacyclic triterpene compounds on psoriasis, providing potential candidate compounds for drug development.

New Treatment Addressing the Pathogenesis of Psoriasis

Psoriasis is an immune cell-mediated inflammatory skin disease. The interleukin (IL)23/IL17 axis plays an important role in the development of psoriasis. The effectiveness of biologic treatments such as tumor necrosis factor (TNF)α inhibitors (infliximab, adalimumab, certolizumab pegol), IL23 inhibitors (ustekinumab, guselkumab, tildrakizumab, risankizumab), and IL17 inhibitors (secukinumab, ixekizumab, brodalumab) have verified these findings. Immune-related cells such as dendritic cells (DCs) and macrophages, in addition to Toll-like receptors and cytokines such as interferon (IFN)α, TNFα, IFNɤ, IL12, IL22, IL23, and IL17, are related to the pathogenesis of psoriasis. Here, we first review new insights regarding the pathogenesis of psoriasis, as it relates to DCs, Langerhans cells, macrophages, the signal transducer and activator of transcription 3 pathway, and aryl hydrocarbon receptor in cutaneous vascular endothelial cells. Based on these findings, we summarize currently available oral treatments and biologics. Furthermore, we describe a new treatment option including Janus kinase inhibitor, tyrosine kinase 2 inhibitor, modulator of sphingosine 1-phosphate receptor 1, and Rho-associated kinase 2 inhibitor.

Decoding IL-23 Signaling Cascade for New Therapeutic Opportunities

The interleukin 23 (IL-23) is a key pro-inflammatory cytokine in the development of chronic inflammatory diseases, such as psoriasis, inflammatory bowel diseases, multiple sclerosis, or rheumatoid arthritis. The pathological consequences of excessive IL-23 signaling have been linked to its ability to promote the production of inflammatory mediators, such as IL-17, IL-22, granulocyte-macrophage colony-stimulating (GM-CSF), or the tumor necrosis factor (TNFα) by target populations, mainly Th17 and IL-17-secreting TCRγδ cells (Tγδ17). Due to their pivotal role in inflammatory diseases, IL-23 and its downstream effector molecules have emerged as attractive therapeutic targets, leading to the development of neutralizing antibodies against IL-23 and IL-17 that have shown efficacy in different inflammatory diseases. Despite the success of monoclonal antibodies, there are patients that show no response or partial response to these treatments. Thus, effective therapies for inflammatory diseases may require the combination of multiple immune-modulatory drugs to prevent disease progression and to improve quality of life. Alternative strategies aimed at inhibiting intracellular signaling cascades using small molecule inhibitors or interfering peptides have not been fully exploited in the context of IL-23-mediated diseases. In this review, we discuss the current knowledge about proximal signaling events triggered by IL-23 upon binding to its membrane receptor to bring to the spotlight new opportunities for therapeutic intervention in IL-23-mediated pathologies.

Discovery of BMS-986251: A Clinically Viable, Potent, and Selective RORγt Inverse Agonist

Novel tricyclic analogues were designed, synthesized, and evaluated as RORγt inverse agonists. Several of these compounds were potent in an IL-17 human whole blood assay and exhibited excellent oral bioavailability in mouse pharmacokinetic studies. This led to the identification of compound 5, which displayed dose-dependent inhibition of IL-17F production in a mouse IL-2/IL-23 stimulated pharmacodynamic model. In addition, compound 5 was studied in mouse acanthosis and imiquimod-induced models of skin inflammation, where it demonstrated robust efficacy comparable to a positive control. As a result of this excellent overall profile, compound 5 (BMS-986251) was selected as a clinically viable developmental candidate.

Tazarotene-loaded in situ gels for potential management of psoriasis: biocompatibility, anti-inflammatory and analgesic effect

Psoriasis is a chronic autoinflammatory disorder characterized by patches of abnormal skin. For psoriasis management, the application of topical retinoids as Tazarotene is recommended. However, Tazarotene could induce skin irritation limiting its use. Herein, it is evaluated the possible usage of in situ gels for tazarotene skin delivery. The topical in situ gels were developed using thermosensitive poloxamers via cold method. They were examined for their appearance, sol-gel temperature, clarity, pH, viscosity, in vitro release, and stability. Their biocompatibility was evaluated by investigating their cytotoxicity and irritation inducing capacity. The possible anti-inflammatory and analgesic activities were determined by measuring the nitric oxide and prostaglandin E₂ levels production in LPS-stimulated RAW264.7 murine macrophage cells. It was revealed that the in situ gels had no cytotoxic effect (∼95-100% cell viability) and nor irritation potential (∼97% cell viability), according to the in vitro EpiDerm™ reconstituted skin irritation test. Additionally, the 10% tazarotene-in situ gels showed possible analgesic activity since the production of prostaglandin E₂ (PGE₂) was decreased. In further, both concentrations of 5% and 10% tazarotene-in situ gels inhibited significantly the nitrite oxide production at 16% and 19%, respectively. Finally, the prepared in situ gels can act as a potential non-irritant alternative option for tazarotene topical skin delivery.

Th17 Cells in Inflammatory Bowel Disease: An Update for the Clinician

Studies in humans strongly implicate Th17 cells in the pathogenesis of inflammatory bowel disease. Thus, Th17 cells are major targets of approved and emerging biologics. Herein, we review the role of Th17 in IBD with a clinical focus.

Transcriptional Regulators of T Helper 17 Cell Differentiation in Health and Autoimmune Diseases

T helper (Th) 17 cells are a subtype of CD4 T lymphocytes characterized by the expression of retinoic acid-receptor (RAR)-related orphan receptor (ROR)γt transcription factor, encoded by gene Rorc. These cells are implicated in the pathology of autoimmune inflammatory disorders as well as in the clearance of extracellular infections. The main function of Th17 cells is the production of cytokine called interleukin (IL)-17A. This review highlights recent advances in mechanisms regulating transcription of IL-17A. In particular, we described the lineage defining transcription factor RORγt and other factors that regulate transcription of Il17a or Rorc by interacting with RORγt or by binding their specific DNA regions, which may positively or negatively influence their expression. Moreover, we reported the eventual involvement of those factors in Th17-related diseases, such as multiple sclerosis, rheumatoid arthritis, psoriasis, and Crohn's disease, characterized by an exaggerated Th17 response. Finally, we discussed the potential new therapeutic approaches for Th17-related diseases targeting these transcription factors. The wide knowledge of transcriptional regulators of Th17 cells is crucial for the better understanding of the pathogenic role of these cells and for development of therapeutic strategies aimed at fighting Th17-related diseases.

EFLA 945 restricts AIM2 inflammasome activation by preventing DNA entry for psoriasis treatment

Psoriasis is a chronic inflammatory skin disease that affects about 2% of the general population. Activation of the Absent in Melanoma 2 (AIM2) inflammasome is crucial for immune defense, but it can also cause inflammatory and autoimmune diseases, including psoriasis. We currently lack an AIM2 inflammasome inhibitor that could be used therapeutically. Here, we show that EFLA 945, a safe product of red grape vine leaf extracts, can restrict AIM2 inflammasome activation. Mechanistically, EFLA945 prevents DNA entry into THP-1-derived macrophages, and thereby inhibits cytoplasmic DNA-dependent apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization, caspase-1 activation, and the secretion of interleukin (IL)-1β and IL-18. The major phytochemicals of EFLA 945, resveratrol and peonidin 3-O-glucoside (P3G), appear to be the potential bioactive compounds responsible for its ability to restrict AIM2-dependent IL-1β secretion. Importantly, in an in vivo mouse model, EFLA 945 attenuates imiquimod (IMQ)-induced psoriasis-related pro-inflammatory responses in topical psoriatic skin, including caspase-1 activation, IL-1β maturation, and IL-17 production, and decreases the severity of psoriasis. Together, these results demonstrate that the safe natural product, EFLA 945, can restrict the AIM2 inflammasome activation through preventing DNA entry and may prove beneficial for treating psoriasis.

Glucocorticoids and Glucocorticoid-Induced-Leucine-Zipper (GILZ) in Psoriasis

Psoriasis is a prevalent chronic inflammatory human disease initiated by impaired function of immune cells and epidermal keratinocytes, resulting in increased cytokine production and hyperproliferation, leading to skin lesions. Overproduction of Th1- and Th17-cytokines including interferon (IFN)-γ, tumor necrosis factor (TNF)-α, interleukin (IL)-23, IL-17, and IL-22, is a major driver of the disease. Glucocorticoids (GCs) represent the mainstay protocol for treating psoriasis as they modulate epidermal differentiation and are potent anti-inflammatory compounds. The development of safer GC-based therapies is a high priority due to potentially severe adverse effects associated with prolonged GC use. Specific efforts have focused on downstream anti-inflammatory effectors of GC-signaling such as GC-Induced-Leucine-Zipper (GILZ), which suppresses Th17 responses and antagonizes multiple pro-inflammatory signaling pathways involved in psoriasis, including AP-1, NF-κB, STAT3, and ROR-γt. Here we review evidence regarding defective GC signaling, GC receptor (GR) function, and GILZ in psoriasis. We discuss seemingly contradicting data on the loss- and gain-of-function of GILZ in the imiquimod-induced mouse model of psoriasis. We also present potential therapeutic strategies aimed to restore GC-related pathways.