Search Results (181)

The glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) are ligand-activated transcription factors that regulate epidermal homeostasis, inflammation, and function. Prior studies using epidermal-specific conditional single and double knockout mice have shown their importance in skin physiology; however, clinically human disease is largely treated pharmacologically. Our objective was to examine how systemic MR/GR antagonism affects cutaneous gene expression and epidermal thickness in aged (18-month-old) C57BL/6J female mice. Mice were treated with selective GR (relacorilant), selective MR (eplerenone), or dual GR/MR (miricorilant) antagonists for 8 weeks. Quantitative RT-qPCR analysis of the skin showed that miricorilant significantly upregulated Sgk1, a GR/MR target. Miricorilant also increased the expression of keratinocyte differentiation markers and downregulated key inflammatory cytokines and Col3a1, a collagen subtype associated with tissue remodeling. Relacorilant suppressed Scnn1g, a subunit of the epithelial sodium channel. None of the antagonists significantly altered proliferation markers, epidermal thickness, or regulators of glucocorticoid activity. Our findings show that miricorilant downregulated inflammatory cytokines and increased differentiation marker expression without affecting epidermal thickness, suggesting its potential to treat inflammatory skin diseases. The results contrast with data from GR/MR knockout studies, highlighting the likely significance of receptor dynamics. Further studies of antagonist effects on receptor interactions with co-regulators appear warranted. Full article

T lymphocytes in human skin play essential roles in immune surveillance and tissue homeostasis, with distinct populations residing in the epidermal and dermal compartments. To characterize the molecular basis of their compartmentalized functional specialization, we performed proteomic analysis of total T cell populations isolated from healthy human skin, combining flow cytometry and liquid chromatography–tandem mass spectrometry. We quantified 5985 proteins across epidermal and dermal T cell populations, identifying 2177 significantly differentially expressed proteins (FDR < 0.05), including 1008 with >2-fold changes. Compared with dermal T cells, epidermal T cells showed elevated intensity of tissueresidency marker CD69, co-stimulatory protein CD27, complement components (C3, C4a, and Factors B and D), and proteins involved in oxidative phosphorylation and cholesterol metabolism. Epidermal T cells also exhibited higher levels of antimicrobial S100 proteins, chemokine receptor CCR6, IL-18, and MHC class I molecules, while, in contrast, dermal T cells showed increased expression of CXCR4, IL-16, and MHC class II-related proteins. While these distinct proteomic signatures suggest compartment-specific adaptations in metabolism, immune surveillance, and antigen presentation, the results should be interpreted as exploratory, given methodological limitations. Nonetheless, this study provides a valuable molecular resource for understanding the specialization of T cells within different skin layers and offers a basis for future investigations into skin immune biology and its potential implications in disease. Full article

Skin aging is characterized by compromised epidermal homeostasis and dermo-epidermal junction (DEJ) integrity, resulting in reduced stem cell potential and impaired tissue regeneration. This study investigated the effects of Andrographis paniculata extract (APE) on keratinocyte stem cells (KSCs) and DEJ composition in human skin. Using human skin explants and cell culture models, we demonstrated that APE treatment enhances DEJ composition by increasing Collagen IV and Laminin production while decreasing MMP-9 expression, without altering epidermal structure or differentiation. In the same model, APE preserved stemness potential by upregulating markers related to niche components (collagen XVII and β1-integrin), proliferation (Ki-67 and KRT15), and stem cell capacity (Survivin and LRIG1). In vitro studies revealed that APE selectively stimulated KSC proliferation without affecting transit amplifying cells and promoted Collagen IV and Laminin secretion, particularly in KSCs. Furthermore, in a co-culture model simulating a compromised DEJ (UVB-induced), APE increased Laminin production in KSCs, suggesting a protective effect against photo-damage. These findings indicate that APE enhances DEJ composition and preserves stem cell potential, highlighting its promise as a candidate for skin anti-aging strategies targeting stem cell maintenance and extracellular matrix stability to promote skin regeneration and repair. Full article

Objectives: Light intensity is a critical environmental factor regulating plant growth, development, and stress adaptation. However, the physiological and molecular mechanisms underlying light responses in Aconitum kusnezoffii, a valuable alpine medicinal plant, remain poorly understood. This study aimed to elucidate the adaptive strategies of A. kusnezoffii under different light intensities through integrated physiological and transcriptomic analyses. Methods: Two-year-old A. kusnezoffii plants were exposed to three controlled light regimes (790, 620, and 450 lx). Leaf anatomical traits were assessed via histological sectioning and microscopic imaging. Antioxidant enzyme activities (CAT, POD, and SOD), membrane lipid peroxidation (MDA content), osmoregulatory substances, and carbon metabolites were quantified using standard biochemical assays. Transcriptomic profiling was conducted using Illumina RNA-seq, with differentially expressed genes (DEGs) identified through DESeq2 and functionally annotated via GO and KEGG enrichment analyses. Results: Moderate light (620 lx) promoted optimal leaf structure by enhancing palisade tissue development and epidermal thickening, while reducing membrane lipid peroxidation. Antioxidant defense capacity was elevated through higher CAT, POD, and SOD activities, alongside increased accumulation of soluble proteins, sugars, and starch. Transcriptomic analysis revealed DEGs enriched in photosynthesis, monoterpenoid biosynthesis, hormone signaling, and glutathione metabolism pathways. Key positive regulators (PHY and HY5) were upregulated, whereas negative regulators (COP1 and PIFs) were suppressed, collectively facilitating chloroplast development and photomorphogenesis. Trend analysis indicated a “down–up” gene expression pattern, with early suppression of stress-responsive genes followed by activation of photosynthetic and metabolic processes. Conclusions: A. kusnezoffii employs a coordinated, multi-level adaptation strategy under moderate light (620 lx), integrating leaf structural optimization, enhanced antioxidant defense, and dynamic transcriptomic reprogramming to maintain energy balance, redox homeostasis, and photomorphogenic flexibility. These findings provide a theoretical foundation for optimizing artificial cultivation and light management of alpine medicinal plants. Full article

Environmental exposure to per- and polyfluoroalkyl substances (PFASs) has been increasingly associated with skin disorders, including atopic dermatitis (AD); however, the underlying molecular mechanisms remain unclear. This study aimed to evaluate the effects of perfluorononanoic acid (PFNA) and perfluorooctanoic acid (PFOA)—two widely detected PFASs—on epidermal function and gene expression in Human Epithelial Keratinocyte, neonatal (HEKn). We assessed cell viability, morphology, and transcriptomic changes using in vitro assays and RNA-seq analysis from a neonatal cohort. PFASs induced dose-dependent cytotoxicity and downregulation of barrier-related genes. Ingenuity pathway analysis identified calcitriol as a suppressed upstream regulator. Functional validation revealed that calcitriol partially reversed the PFAS-induced suppression of antimicrobial peptide genes. These findings support the hypothesis that PFASs may contribute to AD-like skin pathology by impairing vitamin D receptor signaling and antimicrobial defense, and calcitriol demonstrates potential as a protective modulator. This study provides mechanistic insights into the impact of environmental toxicants on skin homeostasis and suggests a potential protective role for calcitriol in PFAS-induced skin barrier damage. Full article

Background: Long non-coding RNAs (lncRNAs) are increasingly recognized as pivotal regulators in both inflammatory and neoplastic skin disorders. Their implications in numerous biological processes, including gene expression, immune responses, and epidermal homeostasis, suggest potential applications as diagnostic and prognostic markers, as well as therapeutic targets. Methods: We conducted a literature search on lncRNAs involved in both psoriasis and cutaneous squamous cell carcinoma (cSCC), highlighting overlapping pathogenic mechanisms. Results: Several lncRNAs, such as HOTAIR, MALAT-1, H19, and uc.291, display dysregulated expression in both psoriasis and cSCC, influencing keratinocyte proliferation and apoptosis, immune modulation, cytokine signaling, and the synthesis of epidermal proteins. Conclusions: The intersection of lncRNA function in chronic inflammation and skin carcinogenesis underscores their role in mediating the transition from psoriatic inflammation to tumorigenesis, offering new insights into disease susceptibility; further investigation through functional studies and clinical validation are required. The study of lncRNA-mediated molecular pathways is particularly relevant given the increased risk of non-melanoma skin cancers and lymphoproliferative disorders among patients with chronic and severe forms of psoriasis. Full article

Silver nanoparticles (AgNPs), lauded for their unique antibacterial and physicochemical attributes, are proliferating across industrial sectors, raising concerns about their environmental fate, in aquatic systems. While “green” synthesis offers a sustainable production route with reduced chemical byproducts, the safety of these AgNPs for aquatic fauna remains uncertain due to nanoparticle-specific effects. Conversely, mast cells play crucial roles in fish immunity, orchestrating innate and adaptive immune responses by releasing diverse mediators and recognizing danger signals. Goblet cells are vital for mucosal immunity and engaging in immune surveillance, regulation, and microbiota interactions. The interplay between these two cell types is critical for maintaining mucosal homeostasis, is central to defending against fish diseases and is highly responsive to environmental cues. This study investigates the acute dermatotoxicity of environmentally relevant AgNP concentrations (0, 0.031, 0.250, and 5.000 μg/L) on zebrafish epidermis. A 96 h assay revealed a biphasic response: initial mucin hypersecretion at lower AgNP levels, suggesting an early stress response, followed by a concentration-dependent collapse of mucosal integrity at higher exposures, with mucus degradation and alarm cell depletion. A rapid and generalized increase in epidermal mucus production was observed across all AgNP exposure groups within two hours of exposure. Further mechanistic insights into AgNP-induced toxicity were revealed by concentration-dependent alterations in goblet cell dynamics. Lower AgNP concentrations initially led to an increase in both goblet cell number and size. However, at the highest concentration, this trend reversed, with a significant decrease in goblet cell numbers and size evident between 48 and 96 h post-exposure. The simultaneous presence of neutral and acidic mucins indicates a dynamic epidermal response suggesting a primary physical barrier function, with acidic mucins specifically upregulated early on to enhance mucus viscosity, trap AgNPs, and inhibit pathogen invasion, a clear defense mechanism. The subsequent reduction in mucin-producing cells at higher concentrations signifies a critical breakdown of this protective strategy, leaving the epidermis highly vulnerable to damage and secondary infections. These findings highlight the vulnerability of fish epidermal defenses to AgNP contamination, which can potentially compromise osmoregulation and increase susceptibility to threats. Further mechanistic research is crucial to understand AgNP-induced epithelial damage to guide sustainable nanotechnology. Full article

Transient receptor potential classical or cation channels (TRPCs) are integral to tumor biology, particularly in maintaining Ca²⁺ homeostasis within cancer cells. TRPC5, a pH-sensitive member of this family, may act as a signaling molecule in the altered microenvironment of solid tumors, which are characterized by an inverted pH-gradient—with decreased extracellular and increased intracellular pH—that promotes tumor progression. This study addresses a gap in the field, as there is currently limited research on TRPC5, particularly regarding its potential role as a tumor marker. While TRPCs are known to be involved in cancer biology, the specific role of TRPC5 in solid tumors, including its potential role as a diagnostic marker, remains largely unexplored. This study is the first to examine TRPC5 expression profiles in common skin cancers, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM), and nevus cell nevi (NCN). Our findings reveal that the frequency of TRPC5 expression in BCC is significantly lower compared to SCC and epidermal portions of NCN and MM. These results suggest that TRPC5 could serve as an immunohistochemical marker to distinguish SCC from BCC. Additionally, this study lays the groundwork for future research into the role of TRPC5 in tumor progression and metastasis, especially since BCCs, which rarely metastasize, are predominantly negative for TRPC5. Full article

Breast cancer is the leading threat to the health of women, with a rising global incidence linked to social and psychological factors. Among its subtypes, triple-negative breast cancer (TNBC), which lacks estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression, is highly heterogeneous with early metastasis and a poor prognosis, making it the most challenging subtype. Mounting evidence shows that the mitochondrial quality control (MQC) system is vital for maintaining cellular homeostasis. Dysfunction of the MQC is tied to tumor cell invasiveness, metastasis, and chemoresistance. This paper comprehensively reviews the molecular link between MQC and TNBC development. We focused on how abnormal MQC affects TNBC progression by influencing chemoresistance, immune evasion, metastasis, and cancer stemness. On the basis of current studies, new TNBC treatment strategies targeting key MQC nodes have been proposed. These findings increase the understanding of TNBC pathogenesis and offer a theoretical basis for overcoming treatment challenges, providing new research angles and intervention targets for effective precision therapy for TNBC. Full article

Systemic sclerosis (SSc) is an autoimmune fibrotic disorder affecting the skin and internal organs, categorized as either limited cutaneous SSc, where distal areas of skin are involved, or diffuse cutaneous SSc, where more extensive proximal skin involvement is seen. Vascular remodelling and internal organ involvement are frequent complications in both subsets. Multiple pathogenic mechanisms have been demonstrated, including production of disease-specific autoantibodies, endothelial cell damage at an early stage, infiltration of involved tissues by immune cells, as well as environmental factors triggering the onset such as solvents and viruses. Although not strongly familial, susceptibility to SSc is associated with multiple single nucleotide polymorphisms in immunoregulatory genes relevant to antigen presentation, T cell signalling and adaptive immunity, as well as innate immunity. In addition, several lines of evidence demonstrate abnormalities within the epithelial cell layer in SSc. Macroscopically, the SSc epidermis is pigmented, thickened and stiff and strongly promotes myofibroblasts in co-culture. Moreover, multiple activating factors and pathways have been implicated in the disease epidermis, including wound healing responses, induction of damage associated molecular patterns (DAMPS) and the release of pro-fibrotic growth factors and cytokines. Similar to SSc, data from studies of cutaneous wound healing indicate a major role for epidermal keratinocytes in regulating local fibroblast responses during repair of the wound defect. Since the epithelium is strongly exposed to environmental factors and richly populated with protective immune cells, it is possible that disease-initiating mechanisms in SSc involve dysregulated immunity and tissue repair within this cell layer. Treatments designed to restore epithelial homeostasis or else disrupt epithelial–fibroblast cross-talk could be of benefit in this severe and resistant disease. Accordingly, single cell analysis has confirmed an active signature in SSc keratinocytes, which was partially reversed following a period of JAK inhibitor therapy. Full article

Maintaining the physiological acid–base balance of the skin is critical to preserving the integrity of the epidermal barrier and preventing irritation. This study investigates the short-term effects of natural soaps, prepared using cold and hot processes, on skin surface pH. A double-blind, controlled design was applied to assess changes in pH following application of soap formulations. pH levels were measured in vivo using non-invasive instrumentation at baseline and 2, 15 and 30 min post-application in 41 adult volunteers. The results demonstrated a significant increase in skin pH immediately after exposure to both types of natural soap, with elevated values persisting for up to 30 min. These changes were associated with potential disruption of the skin’s acid mantle and reduced buffering capacity. The findings highlight the importance of pH considerations in the formulation and routine use of natural cleansers. Although natural soaps are often perceived as gentle alternatives, their alkalinity may transiently disturb the skin’s acid–base homeostasis, potentially leading to increased transepidermal water loss and barrier impairment. This study supports the need for reformulation strategies and consumer awareness regarding the physicochemical impact of cleansing agents on skin health. Full article

Psoriasis is a chronic immune-mediated inflammatory skin disorder characterized by keratinocyte hyperproliferation, impaired epidermal barrier function, and immune dysregulation. The Th17/IL-23 axis plays a central role in its pathogenesis, promoting the production of key pro-inflammatory cytokines such as IL-17, IL-23, and TNF-α, which sustain chronic inflammation and epidermal remodeling. Emerging evidence suggests that SARS-CoV-2 may trigger new-onset or exacerbate existing psoriasis, likely through viral protein-induced activation of toll-like receptors (TLR2 and TLR4). This leads to NF-κB activation, cytokine release, and enhanced Th17 responses, disrupting immune homeostasis. Erythrodermic psoriasis (EP), a rare and severe variant, presents with generalized erythema and desquamation, often accompanied by systemic complications, including infection, electrolyte imbalance, and hemodynamic instability. In a murine model of SARS-CoV-2 infection, we found notable cutaneous changes: dermal collagen deposition, hair follicle destruction, and subcutaneous adipose loss. Parallel findings were seen in a rare clinical case (only the third reported case) of EP in a patient with refractory psoriasis, who developed erythroderma after off-label initiation of dupilumab therapy. The patient’s histopathology closely mirrored the changes seen in the SARS-CoV-2 model. Histological evaluations also reveal similarities between psoriasis flare-ups following dupilumab treatment and cutaneous manifestations of COVID-19, suggesting a shared inflammatory pathway, potentially mediated by heightened type 1 and type 17 responses. This overlap raises the possibility of a latent connection between SARS-CoV-2 infection and increased psoriasis severity. Since the introduction of COVID-19 vaccines, sporadic cases of EP have been reported post-vaccination. Although rare, these events imply that vaccine-induced immune modulation may influence psoriasis activity. Our findings highlight a convergence of inflammatory mediators—including IL-1, IL-6, IL-17, TNF-α, TLRs, and NF-κB—across three triggers: SARS-CoV-2, vaccination, and dupilumab. Further mechanistic studies are essential to clarify these relationships and guide management in complex psoriasis cases. Full article

Protein kinase CK2 has emerged as a pivotal regulator of cellular processes involved in skin homeostasis, including cell proliferation, differentiation and inflammatory response regulation. In fact, CK2 activity dysregulation is implicated in the pathogenesis of different skin diseases, such as psoriasis, cancer and inflammatory dermatoses. CK2 overactivation fosters keratinocyte proliferation and pro-inflammatory cytokine production through the STAT3 and Akt pathways in psoriasis, thus contributing to epidermal hyperplasia and inflammation. In the realm of oncology, CK2 overexpression correlates with tumor progression, facilitating cell survival and metastasis in melanoma and non-melanoma skin cancers. Pharmacological inhibition of CK2 has demonstrated therapeutic potential, with CX-4945 (Silmitasertib) as the most studied adenosine triphosphate-competitive inhibitor (ATP-competitive inhibitor). Preclinical models reveal that CK2 inhibitors effectively mitigate pathological features of psoriasis, regulate keratinocyte differentiation, and suppress tumor growth in skin cancers. These inhibitors also potentiate the efficacy of conventional chemotherapeutics and exhibit anti-inflammatory effects in dermatological conditions. Future research will aim to enhance the specificity and delivery of CK2-targeting therapies, including topical formulations, to minimize systemic side effects. Combination therapies integrating CK2 inhibitors with other agents might offer synergistic benefits in managing skin diseases. This review underscores CK2’s critical role in skin and its therapeutic potential as a pharmacological target, advocating for innovative approaches to harness CK2 inhibition in dermatology. Full article

Darier′s disease (DD) is a rare, autosomal dominant genodermatosis caused by pathogenic variants in the ATP2A2 gene, which encodes the SERCA2 protein, an endoplasmic reticulum ATPase Ca²⁺ transporter. These mutations impair the intracellular calcium homeostasis leading to increased protein misfolding, endoplasmic reticulum (ER) stress response, and the activation of the unfolded protein response (UPR), culminating in keratinocyte apoptosis and anomalies in interfollicular epidermal stratification. Clinically, the disease is characterized by the presence of skin lesions with hyperkeratotic papules and an increased susceptibility to inflammatory reactions, bacterial and viral infections. The histological hallmarks include acantholysis, dyskeratosis, and increased apoptotic keratinocytes, referred to as “corp ronds”. The SERCA2b isoform is expressed not only in the epidermis but it is present ubiquitously in all tissues, suggesting that its alteration may have multi-organ effects. The review aims to provide a broad overview of the pathology, from intracellular dysfunction to the clinical manifestations, elucidating the molecular effects of SERCA2 variants found in DD patients and exploring the potential cell signaling pathways that may contribute to disease progression. Beginning with an examination of the cellular alterations, our work then shifts to exploring their impact in an organ-specific context, providing insights into new potential therapeutic strategies tailored to clinical manifestations. Full article

Vitamin D, a hormone synthesized in the skin through ultraviolet B radiation (UVB), plays a crucial role not only in calcium and phosphate homeostasis but also in regulating skin homeostasis and modulating immune responses. In keratinocytes, vitamin D is converted to its active form, 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D), which interacts with the vitamin D receptor (VDR) to regulate gene expression involved in proliferation, differentiation, and antimicrobial defense. Dysregulation of this pathway has been implicated in inflammatory skin diseases such as psoriasis, atopic dermatitis, acne vulgaris, and hidradenitis suppurativa. These conditions are associated with altered epidermal differentiation, immune imbalance, and microbial interactions, where vitamin D plays a modulatory role by suppressing proinflammatory cytokines, enhancing antimicrobial peptide synthesis, and restoring skin barrier integrity. Topical vitamin D analogues have shown therapeutic benefits in psoriasis, while emerging evidence supports the adjunctive role of vitamin D supplementation in acne, hidradenitis suppurativa, and atopic dermatitis. Despite promising associations between low serum vitamin D levels and disease severity, a causal relationship remains uncertain. This review integrates molecular mechanisms with clinical findings, emphasizing the role of vitamin D in cutaneous physiology and pathology, and highlights the need for further research into targeted supplementation strategies in dermatological disorders. Full article