Application of Baricitinib in Dermatology

Up-and-Coming Drugs for the Treatment of Vitiligo

Vitiligo is a chronic autoimmune disease that causes depigmented patches on the skin. It affects 0.5%-2.0% of the global population. It goes beyond physical appearance, often leading to stigmatization, low self-esteem, and depression, burdening patients with psychosocial challenges. The pathogenesis of vitiligo involves the loss of melanocytes due to autoreactive CD8+ T cells, triggered by environmental stressors and exacerbated by cellular vulnerabilities and immune responses. The release of danger signals and pro-inflammatory factors initiates an immune cascade perpetuating melanocyte destruction, mainly driven by interferon-γ and the C-X-C motif chemokine ligand 9/10-chemokine receptor 3 axis. Long-lasting tissue-resident memory T cells (Trms) and cytokines contribute to lesion persistence. Current treatments focus on topical steroids and tacrolimus, systemic steroids, and phototherapies, but their efficacy remains suboptimal, necessitating the development of new therapeutic options. Building on recent advancements in understanding the immunological mechanisms in vitiligo pathogenesis, with the initiation of Food and Drug Administration approval of topical ruxolitinib, various potential treatment options such as JAK inhibitors, cytokine blockers, and Trm or regulatory T cell targeting agents are being clinically researched and anticipated for vitiligo based on both preclinical and clinical data. This review aims to categorize and summarize the diverse investigational drugs currently undergoing clinical trials for vitiligo. By examining clinical outcomes, it is anticipated that this review will bring hope to dermatologists and patients regarding vitiligo, a condition that has historically posed challenges and transform it into a realm of potential possibilities.

CS12192, a novel JAK3/JAK1/TBK1 inhibitor, attenuates autoimmune dermatoses in murine models

OBJECTIVE

Autoimmune dermatosis (AID) occurs when the body's immune system attacks skin or tissue, leading to various types of skin disorders or injuries. Recent studies show that Janus kinases (JAKs) play critical roles in autoimmune diseases including AID by regulating multiple cytokine signaling pathways. CS12192, a novel JAK3/JAK1/TBK1 inhibitor, has been reported to exert ameliorative effects in rheumatoid arthritis. However, the efficacy of CS12192 on AID is undetermined. This study aims to investigate the therapeutic efficacy of CS12192 on psoriasis (PSO), systemic lupus erythematosus (SLE) and atopic dermatitis (AD) in mouse models.

METHODS

Interleukin-23 (IL-23)-induced PSO model, spontaneous SLE model of MRL/MpJ-Faslpr/J (MRL/lpr) mice, and oxazolone (OXA) and dinitrochlorobenzene (DNCB)-induced murine AD models were used for the evaluation of curative effects of CS12192, respectively. The skin lesion, biochemical parameters, ear thickness, ear weight and histopathology were assessed accordingly.

RESULTS

In PSO model, mice treated with CS12192 show reduced ear thickness and ear weight as compared with vehicle. In SLE model, CS12192 ameliorates cutaneous parameters such as lymphadenectasis and skin lesion but not systematic parameters such as proteinuria concentration and score, serum dsDNA and BUN concentration. In AD models, CS12192 dose-dependently improves ear swelling and reduces histological scores, exerting equivalent efficacy with baricitinib, a marketed JAK1/JAK2 inhibitor.

CONCLUSION

Our findings suggest that the novel JAK3/JAK1/TBK1 inhibitor CS12192 is potentially to alleviate autoimmune dermatosis.

Monotropein mitigates atopic dermatitis-like skin inflammation through JAK/STAT signaling pathway inhibition

Atopic dermatitis (AD) is a globally increasing chronic inflammatory skin disease with limited and potentially side-effect-prone treatment options. Monotropein is the predominant iridoid glycoside in Morinda officinalis How roots, which has previously shown promise in alleviating AD symptoms. This study aimed to systematically investigate the pharmacological effects of monotropein on AD using a 2, 4-dinitrochlorobenzene (DNCB)/Dermatophagoides farinae extract (DFE)-induced AD mice and tumor necrosis factor (TNF)-α/interferon (IFN)-γ-stimulated keratinocytes. Oral administration of monotropein demonstrated a significant reduction in AD phenotypes, including scaling, erythema, and increased skin thickness in AD-induced mice. Histological analysis revealed a marked decrease in immune cell infiltration in skin lesions. Additionally, monotropein effectively downregulated inflammatory markers, encompassing pro-inflammatory cytokines, T helper (Th)1 and Th2 cytokines, and pro-inflammatory chemokines in skin tissues. Notably, monotropein also led to a considerable decrease in serum immunoglobulin (Ig)E and IgG2a levels. At a mechanistic level, monotropein exerted its anti-inflammatory effects by suppressing the phosphorylation of Janus kinase / signal transducer and activator of transcription proteins in both skin tissues of AD-induced mice and TNF-α/IFN-γ-stimulated keratinocytes. In conclusion, monotropein exhibited a pronounced alleviation of AD symptoms in the experimental models used. These findings underscore the potential application of monotropein as a therapeutic agent in the context of AD, providing a scientific basis for further exploration and development.

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.

Mass Spectrometry-Based Proteomics Analysis Unveils PTPRS Inhibits Proliferation and Inflammatory Response of Keratinocytes in Psoriasis

In this study, we used data-independent acquisition-mass spectrometry (DIA-MS) to analyze the serum proteome in psoriasis vulgaris (PsO). The serum proteomes of seven healthy controls and eight patients with PsO were analyzed using DIA-MS. Weighted gene co-expression network analysis was used to identify differentially expressed proteins (DEPs) that were closely related to PsO. Hub proteins of PsO were also identified. The Proteomics Drug Atlas 2023 was used to predict candidate hub protein drugs. To confirm the expression of the candidate factor, protein tyrosine phosphatase receptor S (PTPRS), in psoriatic lesions and the psoriatic keratinocyte model, immunohistochemical staining, quantitative real-time polymerase chain reaction, and western blotting were performed. A total of 129 DEPs were found to be closely related to PsO. The hub proteins for PsO were PVRL1, FGFR1, PTPRS, CDH2, CDH1, MCAM, and THY1. Five candidate hub protein drugs were identified: encorafenib, leupeptin, fedratinib, UNC 0631, and SCH 530348. PTPRS was identified as a common pharmacological target for these five drugs. PTPRS knockdown in keratinocytes promoted the proliferation and expression of IL-1α, IL-1β, IL-23A, TNF-α, MMP9, CXCL8, and S100A9. PTPRS expression was decreased in PsO, and PTPRS negatively regulated PsO. PTPRS may be involved in PsO pathogenesis through the inhibition of keratinocyte proliferation and inflammatory responses and is a potential treatment target for PsO.

Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches

Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.

A systematic review of case series and clinical trials investigating systemic oral or injectable therapies for the treatment of vitiligo

AIMS AND OBJECTIVES

The purpose of this study is to investigate the effectiveness and safety of oral and injectable systemic treatments, such as methotrexate, azathioprine, cyclosporine, tofacitinib, baricitinib, corticosteroids, statins, zinc, apremilast, etc., for treating vitiligo lesions.

METHOD

Databases including PubMed, Scopus, and Web of Science were meticulously searched for studies spanning from 2010 to August 2023, focusing on systemic oral and injectable therapies for vitiligo, using comprehensive keywords and search syntaxes tailored to each database. Key data extracted included study design, treatment efficacy, patient outcomes, patient satisfaction, and safety profiles.

RESULTS

In a total of 42 included studies, oral mini-pulse corticosteroid therapy (OMP) was the subject of six studies (14.2%). Minocycline was the focus of five studies (11.9%), while methotrexate, apremilast, and tofacitinib each were examined in four studies (9.5%). Antioxidants and Afamelanotide were the subjects of three studies each (7.1%). Cyclosporine, simvastatin, oral zinc, oral corticosteroids (excluding OMP) and injections, and baricitinib were each explored in two studies (4.8%). Azathioprine, mycophenolate mofetil, and Alefacept were the subjects of one study each (2.4%).

CONCLUSION

Systemic treatments for vitiligo have been successful in controlling lesions without notable side effects. OMP, Methotrexate, Azathioprine, Cyclosporine, Mycophenolate mofetil, Simvastatin, Apremilast, Minocycline, Afamelanotide, Tofacitinib, Baricitinib, Antioxidants, and oral/injectable corticosteroids are effective treatment methods. However, oral zinc and alefacept did not show effectiveness.

Periplogenin inhibits pathologic synovial proliferation and infiltration in rheumatoid arthritis by regulating the JAK2/3-STAT3 pathway

Rheumatoid arthritis (RA) is an autoimmune disease that affects joints, causing inflammation, synovitis, and erosion of cartilage and bone. Periplogenin is an active ingredient in the anti-rheumatic and anti-inflammatory herb, cortex periplocae. We conducted a study using a CIA model and an in vitro model of fibroblast-like synoviocytes (FLS) induced by Tumor Necrosis Factor-alpha (TNF-α) stimulation. We evaluated cell activity, proliferation, and migration using the CCK8 test, EDU kit, and transwell assays, as well as network pharmacokinetic analysis of periplogenin targets and RA-related effects. Furthermore, we measured inflammatory factors and matrix metalloproteinases (MMPs) expression using ELISA and qRT-PCR assays. We also evaluated joint destruction using HE and Safranin O-Fast Green Staining and examined the changes in the JAK2/3-STAT3 pathway using western blot. The results indicated that periplogenin can effectively inhibit the secretion of inflammatory factors, suppress the JAK2/3-STAT3 pathway, and impede the proliferation and migration of RA FLS. Thus, periplogenin alleviated the Synovial inflammatory infiltration of RA.

Infectious adverse events in patients with atopic dermatitis treated with baricitinib

Baricitinib is a JAK1-2 inhibitor recently approved in Europe and Japan for the treatment of moderate-to-severe atopic dermatitis in adult patients at doses of 2 and 4 mg daily. The aim of this article is to discuss the safety profile of baricitinib in atopic dermatitis using data from clinical trials and the supporting literature, with a focus on infectious adverse events. An integrated analysis of safety data from eight clinical trials described infections as the most frequent treatment-emergent adverse events, mainly of mild-to-moderate severity, notably upper respiratory tract infections and herpes simplex exacerbations. Real-world data are still limited and will contribute to precisely profile the patients that might benefit from this treatment.

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.

Inflammation and Psoriasis: A Comprehensive Review

Psoriasis is an immune-mediated disease with a strong genetic component that brings many challenges to sick individuals, such as chronic illness, and which has multiple associated comorbidities like cardiovascular disease, metabolic syndrome, inflammatory bowel disease, and psychological disorders. Understanding the interplay between the innate and adaptative immune system has led to the discovery of specific cytokine circuits (Tumor Necrosis Factor-alpha (TNF-α), IL-23, IL-17), which has allowed scientists to discover new biomarkers that can be used as predictors of treatment response and pave the way for personalized treatments. In this review, we describe the footprint psoriasis leaves on the skin and beyond, key pathophysiological mechanisms, current available therapeutic options, and drawbacks faced by existing therapies, and we anticipate potential future perspectives that may improve the quality of life of affected individuals.

Efficacy and safety of baricitinib in patients with alopecia areata: evidence to date

Alopecia areata (AA) is a chronic, tissue-specific autoimmune disorder, characterized by non-scaring hair loss, with a global prevalence of approximately 2%. Typically, it affects a young population, with initial onset frequently occurring before the age of 30 years. Even though the exact pathogenesis of AA remains unclear, the predominant hypothesis is the breakdown of immune privilege of the hair follicle, resulting in increased self-antigen and major histocompatibility complex expression in the follicular epithelium. The relapsing nature of the disease negatively impacts patients' quality of life and makes them more susceptible to developing psychiatric comorbidities. Although many treatment modalities have been proposed, there are no currently available treatments able to induce and sustain disease remission. Traditional treatment modalities, despite being widely used, present limited results and a high risk of adverse effects. Hence, there exists an unfulfilled requirement for treatments that are both more efficient and safer. The latest understanding of the pathophysiology of AA and its connection to the JAK-STAT pathway has prompted the advancement of JAK inhibitors. These small-molecule agents function by obstructing the JAK-STAT intracellular signalling pathway. Baricitinib an orally administered, selective JAK1 and JAK2 inhibitor is a promising alternative to the available treatments, and is already approved for the treatment of AA.

Emerging role of baricitinib in dermatology practice: All we need to know!

Baricitinib is a competitive inhibitor of the Janus Kinase family of non-receptor protein kinases, predominantly acting against JAK-1 and JAK-2 subtypes. By downregulating transcription of various pro-inflammatory cytokines, this drug has shown efficacy across various dermatoses. Approved for severe cases of alopecia areata and moderate-severe atopic dermatitis in adults, baricitinib is being increasingly tried across many other indications with promising results. It is prudent that dermatologists remain aware of boxed warnings and precautions with the use of this much-discussed molecule, including its infectious, thrombotic, cardiovascular, and malignant ramifications. Long-term data on the use of baricitinib in dermatological conditions are lacking and further research is warranted since most data on safety profile is extrapolated from its use in rheumatology. The present review aims to highlight the immunopathogenic mechanisms of JAK-1/2 blockade, approved and off-label uses in dermatology, along with a concise review of laboratory monitoring and the side-effect profile of baricitinib.

Baricitinib is Effective in Treating Progressing Vitiligo in vivo and in vitro

Objective

To evaluate the clinical efficacy and safety of baricitinib, a Janus kinase (JAK) inhibitor, in treating patient with progressing vitiligo, and to further explore the regulation of baricitinib on melanocytes (MCs) in vitro.

Methods

Four patients with progressing vitiligo were treated with oral baricitinib for a total of 12 weeks. MCs were cultured in vitro and irradiated by high-dose ultraviolet B (UVB, 150mJ/cm²) to make an MC damaged model (MC-Ds). Baricitinib was added at a final concentration of 25 μM. Dopamine staining and NaOH method were used to measure the tyrosinase activity and melanin level, respectively, real-time quantitative polymerase chain reaction (RT-qPCR) was used to measure the mRNA levels of tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1).

Results

Significant re-pigmentation was observed in the week 12 without obvious side effects. Depigmentation occurred in 2 patients at the 3-month follow-up. Laboratory research found that higher doses of UVB irradiation (150mJ/cm²) could decrease melanin content of MCs, baricitinib (25 μM) could significantly promote tyrosinase activity, melanin content, and TYR, TRP-1 gene expression of MC-Ds.

Conclusion

Our preliminary study showed that baricitinib was effective and safe in treating progressing vitiligo. Baricitinib could promote tyrosinase activity, melanin content and TYR, TRP1 gene expression of MC-Ds in vitro.