Epigenetic control of inflammation in Atopic Dermatitis

Understanding Atopic Dermatitis in Asian and European Population Cohorts Using Complementary Omics Techniques

Atopic dermatitis is highly heterogeneous with respect to pathogenesis, clinical manifestations, and treatment response. There is evidence that ancestry and skin type each contribute to this heterogeneity, indicating the need to improve understanding of disease mechanisms in diverse populations. Methods to integrate multiomics studies have been well-described, but this review focuses on the importance and the strategies needed to integrate data across different ancestral groups, focusing, because of data availability, on Asian and European populations. Skin scientists and clinicians will each benefit from an understanding of how the multiple complimentary layers of omics data may inform future clinical management, from insight into disease pathogenesis and treatment targets.

Investigating the efficacy of gliclazide encapsulated hydrogel in the preclinical mice model for atopic dermatitis

Atopic dermatitis (AD) is a chronic skin inflammatory ailment commonly observed in young children and adults. Various therapeutic modalities are already explored for mitigation of AD but for prolong application very few modalities are recommended. Considering these challenges, we have successfully developed gliclazide-loaded hydrogels using the physical dispersion method. For preclinical assessment, we developed a DNCB induced an AD-like phenotype in mice, characterized by increased dermatitis index, scratching interval, ear thickness and weight, spleen and lymph node enlargement, mast cell infiltration, and elevated oxidative stress. However, topical application of the GLZ hydrogel significantly improved these DNCB-induced symptoms. Mice treated with the GLZ hydrogel exhibited a marked reduction in inflammatory markers in histological evaluations. Specifically, there was a decrease in epidermal thickness and mast cell infiltration compared to the DNCB + Vehicle group. Additionally, the topical GLZ hydrogel attenuated the AD-like phenotype by reducing oxidative stress markers. Importantly, these therapeutic effects occurred without significantly affecting blood glucose levels, highlighting the safety of the topical GLZ hydrogel. These findings demonstrate the potential of GLZ-loaded hydrogels as an effective and safe topical treatment for alleviating the symptoms of AD by targeting oxidative stress and inflammation.

circRNA/TLR interaction: key players in immune regulation and autoimmune diseases

Circular RNAs are a class of non-coding RNAs with covalently closed loops. They have been revealed to regulate immune responses by affecting gene expression. Although initially considered splicing byproducts, new studies have indicated their role in transcriptional and post-transcriptional control, especially with TLRs. TLRs start inflammatory signaling and let the innate immune system recognize PAMPs. circRNAs interact context-dependently with TLR pathways to influence immune homeostasis and inflammation in either pathogenic or protective roles. In autoimmune diseases, dysregulated circRNA expression can aggravate immune responses and damage tissue. CircRNAs can interact with RNA-binding proteins, function as molecular sponges for miRNAs, and change inflammatory pathways like the NF-κB signaling cascade, influencing immune responses. They control adaptive immunity, function of antigen-presenting cells, and cytokine generation. The stability and presence of circRNAs in many body fluids make them therapeutic targets and biomarkers for inflammatory and autoimmune diseases. The several immune control roles of circRNA-TLR interactions are discussed in this review, as well as their consequences for immunologically mediated disease diagnosis and treatment.

The Relationship Between Chronic Pruritus, Attention-Deficit/Hyperactivity Disorder, and Skin Picking-A Case Series and Narrative Review

Chronic pruritus (CP), attention-deficit/hyperactivity disorder (ADHD), and skin picking disorder (SPD) are medical conditions that involve both somatic and psychosocial dimensions, posing unique challenges in clinical management. While CP and SPD are often observed together, the link between ADHD and these conditions is less recognized. This conceptual work describes three women who suffered from a complex interplay of CP, ADHD, and SPD treated at our specialized bi-disciplinary psychodermatological pruritus clinic. Based on our clinical observation and a narrative review of the literature, we assume a bidirectional, triangular relationship between CP, ADHD, and SPD. To support this assumption, we propose two hypotheses: (1) a neurodevelopmental hypothesis, emphasizing that an underlying neurodevelopmental disorder, in this case, ADHD, might present with symptoms like dysfunction of sensory processing, impulsivity, and attention deficits as shared features that reinforce CP and SPD, and (2) a neuroinflammatory hypothesis, suggesting that similar neuroinflammatory signatures promote the co-occurrence of CP, ADHD, and SPD. In addition, we provide specific suggestions derived from our clinical experience on how to manage patients with this complex combination of conditions. Elucidating the interplay between CP, ADHD, and SPD might help develop personalized treatment strategies and improve outcomes.

Research progress in OX40/OX40L in allergic diseases

OX40/OX40L are costimulatory molecules in the tumor necrosis factor superfamily. Numerous studies have shown that OX40/OX40L are involved in immune regulation, especially in the proliferation and differentiation of T cells and the generation of memory T cells, which play important roles in allergic diseases. In recent years, the use of OX40/OX40L as therapeutic targets for treating T-cell-mediated diseases has attracted the interest of scholars. This paper reviews the role of OX40/OX40L in allergic diseases and the progress in clinical treatments targeting this signaling pathway.

Inflammatory Memory in Epidermal Stem Cells - A New Strategy for Recurrent Inflammatory Skin Diseases

The ability of the skin to "remember" has been a potential mechanism for studying recurrent skin diseases. While it has been thought that the ability to retain past encounters is the prerogative of immune cells, it has recently been discovered that skin tissue stem cells can also take on this task. Epithelial stem cells undergoing inflammation retain their "memory" through epigenetic reprogramming and exhibit rapid epithelialization and epidermal proliferation upon secondary stimulation. This is a non-specific memory modality independent of conventional immune memory, in which histone modifications (acetylation and methylation) and specific transcription factors (AP-1 and STAT3) are involved in the establishment of inflammatory memories, and AIM2/Caspase-1/IL-1β mainly performs the rapid effects of memory. This finding is intriguing for addressing recurrent inflammatory skin diseases, which may explain the fixed-site recurrence of inflammatory skin diseases and develop new therapeutic strategies in the future. However, more research is still needed to decipher the mysteries of memory.

Interleukin-31: The Inflammatory Cytokine Connecting Pruritus and Cancer

Interleukin 31 (IL-31) is a proinflammatory cytokine, mainly secreted by Type II helper T cells. It signals through a heterodimeric receptor complex composed of IL-31 receptor α and oncostatin-M receptor β chain. The hallmark feature of IL-31, in its pathological role, is its ability to induce pruritus in mammals. Pruritus is a common symptom and major reason of morbidity in cancer patients, compromising their quality of life. Although, IL-31 is differentially expressed in different tumor types and could promote or inhibit cancer progression, high expression of IL-31 is a contributing factor to advanced stage tumor and severity of pruritus. The simultaneous existence of pruritus and cancer could either result from the aberrations in common proteins that co-exist in both cancer and pruritus or the therapeutic treatment of cancer could indirectly induce pruritus. Although the biology of IL-31 has predominantly been described in skin diseases such as atopic dermatitis and other inflammatory diseases, the precise role of IL-31 in the tumor biology of different cancer types remains elusive. Herein, we summarize the current understanding on the role of this cytokine in the pathogenesis of different cancers.

Severe Allergy as a Chronic Inflammatory Condition From a Systems Biology Perspective

Persistent and unresolved inflammation is a common underlying factor observed in several and seemingly unrelated human diseases, including cardiovascular and neurodegenerative diseases. Particularly, in atopic conditions, acute inflammatory responses such as those triggered by insect venom, food or drug allergies possess also a life-threatening potential. However, respiratory allergies predominantly exhibit late immune responses associated with chronic inflammation, that can eventually progress into a severe phenotype displaying similar features as those observed in other chronic inflammatory diseases, as is the case of uncontrolled severe asthma. This review aims to explore the different facets and systems involved in chronic allergic inflammation, including processes such as tissue remodelling and immune cell dysregulation, as well as genetic, metabolic and microbiota alterations, which are common to other inflammatory conditions. Our goal here was to deepen on the understanding of an entangled disease as is chronic allergic inflammation and expose potential avenues for the development of better diagnostic and intervention strategies.

Deciphering epigenetic regulations in the inflammatory pathways of atopic dermatitis

Atopic dermatitis, commonly referred to as atopic eczema, is a persistent inflammatory skin disorder that predominantly manifests in children but may endure into adulthood. Its clinical management poses challenges due to the absence of a definitive cure, and its prevalence varies across ethnicities, genders, and geographic locations. The epigenetic landscape of AD includes changes in DNA methylation, changes in histone acetylation and methylation, and regulation by non-coding RNAs. These changes affect inflammatory and immune mechanisms, and research has identified AD-specific variations in DNA methylation, particularly in the affected epidermis. Histone modifications, including acetylation, have been associated with the disruption of skin barrier function in AD, suggesting the potential therapeutic benefit of histone deacetylase inhibitors such as belinostat. Furthermore, non-coding RNAs, particularly microRNAs and long non-coding RNAs (lncRNAs), have been implicated in modulating various cellular processes central to AD pathogenesis. Therapeutic implications in AD include the potential use of DNA methylation inhibitors and histone deacetylase inhibitors to correct aberrant methylation patterns and modulate gene expression related to immune responses and skin barrier functions. Additionally, the emerging role of lncRNAs suggests the possibility of using small interfering RNAs or antisense oligonucleotides to inhibit lncRNAs and adjust their regulatory impact on gene expression. In conclusion, the importance of epigenetic elements in AD is becoming increasingly clear as studies highlight the contribution of DNA methylation, histone modifications and, control by non-coding RNAs to the onset and progression of the disease. Understanding these epigenetic changes provides valuable insights for developing targeted therapeutic strategies.

Non-coding RNAs mediated inflammation in breast cancers

Breast cancer is the major cancer that affects women all over the world. The awareness over past several decades has led to intensive screening and detection as well as successful treatments. Still, the breast cancer mortality is unacceptable and needs to be urgently addressed. Among many factors, inflammation has often been associated with tumorigenesis, including breast cancer. More than a third of all breast cancer deaths are marked by deregulated inflammation. The exact mechanisms are still not completely known but among the many putative factors, the epigenetic changes, particularly those mediated by non-coding RNAs are fascinating. microRNAs, long non-coding RNAs as well as circular RNAs seem to impact the inflammation in breast cancer which further highlights their important regulatory role in breast cancer pathogenesis. Understanding inflammation in breast cancer and its regulation by non-coding RNAs is the primary objective of this review article. We attempt to provide the most complete information on the topic in hopes of opening new areas of research and discoveries.

Hinokitiol as a modulator of TLR4 signaling and apoptotic pathways in atopic dermatitis

Atopic dermatitis (AD) poses a significant global health challenge, characterized by dysregulated inflammation and apoptotic processes. This study explores the therapeutic efficacy of hinokitiol, employing a comprehensive in vivo and in vitro approach. Assessment of inflammation-related markers in the animal model included observation of physical appearance, Western blotting, ELISA, and H&E staining. Additionally, the cell culture model enabled the evaluation of apoptosis and ROS levels using MTT assay, crystal violet staining, Western blot, and DCFDA assays. The results revealed hinokitiol's proficiency in ameliorating ear and skin morphology in the DNCB-induced AD model, mediated through the TLR4/MyD88 pathway. Notably, hinokitiol intervention led to a reduction in both M1 and M2 macrophage phenotypes. In vitro investigations demonstrated hinokitiol's ability to enhance cell viability and morphology under TNF-α and IFN-γ induction. Mechanistically, hinokitiol exhibited regulatory effects on apoptosis-related proteins, including Bax, Cytochrome c, Caspase-3, and PARP, thereby averting cellular damage. These findings suggest that hinokitiol is a promising natural compound with significant potential for alleviating inflammation and apoptosis in AD, indicating potential avenues for future therapeutic developments.