Experimental Dermatology最新文献

Vitamin D activates the vitamin D receptor (VDR), which dimerizes preferentially with the retinoid X receptor-α (RXRα). This heterodimer connects with genetic elements responsive to vitamin D, inhibiting or stimulating gene activity. We performed Nanostring® analysis of VDR/RXRα to compare the mRNA expression of this heterodimer and their correlated transcriptomes in non-melanoma skin cancer (basal cell carcinomas (BCC) and squamous cell carcinomas (SCC)) and melanocytic lesions (intradermal nevi (IN), and melanomas (MM)) with control skin. To evaluate VDR, RXRα and other 22 correlated genes in BCC, SCC, IN and MM, paraffin samples had their transcriptomes analysed using Nanostring®, a platform that allows multiple mRNA analyses. There were 46 samples, including 11 BCC, 10 SCC, 10 IN, 12 MM and 3 pools of control skins. Most mRNAs differed between the lesion groups and the control group. BCC and SCC NCOR2 were upregulated; in MM and IN, RXRγ was higher than in the control group. TP53, FOXO3 and MED1 showed a significant difference when we compared the BCC group to the SCC group. Melanoma and intradermal nevi differed only in AhR. VDR and RXRα were lower than the control in all groups. The panel shows a clear difference between the non-melanocytic cancers and, on the other hand, a slight difference between the melanocytic lesions. The study of vitamin D's influence through its receptor and RXRα is an exciting issue for understanding the importance of this pathway, and the present study can impact the prevention and treatment strategies, mainly in non-melanocytic tumours.

Atopic dermatitis (AD) is the most prevalent chronic inflammatory skin disorder, characterised by intense pruritus and recurrent eczematous lesions. Recently, the US FDA has approved Janus kinase (JAK) inhibitors for oral treatment in AD patients. However, oral immunomodulatory agents have demonstrated adverse effects. In previous studies, we demonstrated the efficacy of topical taurodeoxycholate (TDCA), a G protein-coupled receptor 19 (GPCR19) agonist, on AD. In this study, we further evaluated the efficacy of orally administered TDCA on MC903- and dinitrochlorobenzene (DNCB)-induced AD mouse models. Oral administration of TDCA significantly ameliorated AD symptoms and reduced both epidermal and dermal thickness. Additionally, oral TDCA treatment inhibited the infiltration of myeloid and lymphoid cells into AD lesions. TDCA also suppressed the expression of thymic stromal lymphopoietin (TSLP), interleukin (IL)-4, IL-13, IL-33, IL-1β, tumour necrosis factor-alpha (TNF-α) and chemokine (C-C motif) ligand 17 in the skin and blood. Given the previously demonstrated safety profiles of TDCA, oral TDCA may offer a beneficial and safer alternative for AD patients.

The pivotal roles of acetylcholine (ACh) in physiological processes encompass both the nervous and non-neuronal cholinergic systems (NNCS). This review delineates the synthesis, release, receptor interactions, and degradation of ACh within the nervous system, and explores the NNCS in depth within skin cells including keratinocytes, endothelial cells, fibroblasts, macrophages, and other immune cells. We highlight the NNCS's essential functions in maintaining epidermal barrier integrity, promoting wound healing, regulating microcirculation, and modulating inflammatory responses. The potential of the NNCS as a therapeutic target for localized ACh regulation in the skin is discussed, though the translation of these findings into clinical practice remains uncertain due to the complexity of cholinergic signalling and the lack of comprehensive human studies. The review progresses to therapeutic modulation strategies of the NNCS, including AChE inhibitors, nicotinic and muscarinic receptor agonists and antagonists, choline uptake enhancers, and botulinum toxin, highlighting their relevance in dermatology. We highlight the impact of the NNCS on prevalent skin diseases such as psoriasis, atopic dermatitis, rosacea, acne, bullous diseases, hyperhidrosis and hypohidrosis, illustrating its significance in disease pathogenesis and therapy. This comprehensive overview aims to enhance understanding of the NNCS's role in skin health and disease, offering a foundation for future research and therapeutic innovation.

Cutaneous squamous cell carcinoma (cSCC) is a common form of skin cancer, but treatments for advanced cases have limited efficacy. Trophoblast cell-surface antigen 2 (TROP2) is a cell-surface protein that is widely expressed in various tumours, where it exerts significant influence over critical processes such as tumour cell growth, apoptosis, migration, invasion and metastasis. Sacituzumab govitecan, an antibody-drug conjugate (ADC) targeting TROP2, is emerging as a promising strategy for anticancer therapy. In this study, we investigated TROP2 expression in cSCC tissues from 51 patients and evaluated its function in the A431 human SCC cell line. Immunohistochemical analysis revealed TROP2 expression on the plasma membrane of cSCC tissues and A431 cells. A431 cells showed sensitivity to sacituzumab govitecan with a significant concentration-dependent decrease in viable cell number. In addition, Knockdown of TROP2 resulted in decreased expression of cyclin D1 and BCL-2, along with reduced cell viability. Knockdown of TROP2 also resulted in decreased expression of vimentin, along with reduced migratory capacity. These findings suggest that TROP2 plays a crucial role in cSCC cell proliferation and migration, and highlight the potential of sacituzumab govitecan as a promising therapeutic option for cSCC.

The epidermis, the most superficial layer of the human skin, serves a critical barrier function, protecting the body from external pathogens and allergens. Dysregulation of epidermal differentiation contributes to barrier dysfunction and has been implicated in the pathology of various dermatological diseases, including atopic dermatitis (AD). Mucopolysaccharide polysulphate (MPS) is a moisturising agent used to treat xerosis in patients with AD. However, its mechanism of action on keratinocytes, the main constituents of the epidermis, remains unclear. In this study, we investigated the effect of MPS on keratinocytes by subjecting adult human epidermal and three-dimensional cultured keratinocytes to MPS treatment, followed by transcriptome analysis. The analysis revealed that MPS treatment enhances keratinocyte differentiation and suppresses proliferation. We focused on amphiregulin (AREG), a membrane protein that belongs to the epidermal growth factor (EGF) family and possesses a heparin-binding domain, as a significant target among the genes altered by MPS. MPS exerted an inhibitory effect directly on AREG, rather than on EGF receptors or other members of the EGF family. Furthermore, AREG leads to a reduction in epidermal barrier function, whereas MPS contributes to barrier enhancement via AREG inhibition. Collectively, these findings suggest that MPS modulates barrier function through AREG inhibition, offering insights into potential therapeutic strategies for skin barrier restoration.

The hair follicle can cycle throughout a lifetime, undergoing periods of growth (anagen), regression (catagen) and relative quiescence (telogen). The time that a hair follicle spends in each of these stages is crucial to determine the length of hair fibre that it produces. Perturbations in this regard can manifest in various hair diseases such as anagen effluvium, or acute and chronic telogen effluvium. The established ‘dogma’ when considering how many hair follicles there are in each stage has long been that the majority are in anagen (85%–90%), followed by telogen (10%–15%) and catagen (1%–2%). These values are based on various studies using different methodologies such as hair plucking, phototrichograms and histology. However, these methods have flaws when it comes to differentiating between catagen and telogen follicles. We sought to determine the catagen: telogen ratio through the ex vivo stereomicroscopic examination of hundreds of hair follicles removed from the occipital scalp of 14 Caucasian males during routine hair transplantation procedures. Using this methodology, and in agreement with a similar observation by another research group, we found that the percentage of catagen hair follicles was higher (7.5%) than telogen (3.5%) in all patients assessed. Consequently, we believe that the percentage of catagen follicles is clearly underestimated and therefore challenge the current established dogma.

Changes in the expression of cornified envelope (CE) components are a hallmark of numerous pathological skin conditions and aging, underlying the importance of this stratum corneum structure in the homeostasis of the epidermal barrier. We performed a detailed characterisation of LCE6A, a member of the Late Cornified Envelope protein family. Immunohistochemical and immunoblot experiments confirmed that LCE6A is expressed late during epidermal differentiation. Crosslinking assays of recombinant LCE6A performed either in situ on human skin sections or in vitro demonstrated that LCE6A is indeed a substrate of transglutaminases and crosslinked to CEs. LCE6A-derived peptides containing a glutamine-lysine sequence retained these properties of the full-length protein and reinforced the mechanical resistance of CE submitted to sonication. We designed P26, a LCE6A-derived biomimetic peptide that similarly reinforced CE in vitro, and evaluated its protective properties ex vivo, on human skin explants, and in two double blind and vehicle-controlled clinical trials. P26 was able to protect the skin from barrier disruption, to limit the damage resulting from a defective barrier, and could improve the signs of aging such as loss of skin firmness and increased skin roughness. Hence, our detailed characterisation of LCE6A as a component of the CE enabled us to develop a LCE6A-derived peptide, biologically active with a new and original mode of action that could be of great interest as a cosmetic ingredient and a pharmacologic agent.

Hidradenitis Suppurativa (HS) is a chronic, debilitating, auto-inflammatory condition often associated with inflammatory arthritis, significantly impacting patients' quality of life. Early diagnosis of both conditions is crucial for optimal management. The objective of this study was to determine the prevalence and factors associated with the development of inflammatory arthritis among HS patients. A cross-sectional study was conducted between November 2021 and February 2023 at an academic dermatology centre in Canada. Adult patients with HS were consecutively sampled, and 52 patients consented to participate and completed assessments. Variables examined included age, sex, HS severity, treatment, ethnicity, family history, lifestyle factors and comorbidities. The main outcomes were rheumatologist-confirmed inflammatory arthritis diagnosis and associated risk factors. Among 52 patients (24 males, 28 females; mean age: 37.4 years), 12 had inflammatory arthritis. Multivariate analysis revealed that Blacks (OR = 0.10, p < 0.001, CI: 0.026–0.343) and Asians (OR = 0.02, p < 0.001, CI: 0.005–0.109) had lower inflammatory arthritis odds compared to Whites. Every 1-year increase in age at HS onset correlated with a 1.17-fold increase in the odds of developing inflammatory arthritis (OR: 1.17, p < 0.001, CI: 1.12–1.24). Smoking (OR = 0.01, p < 0.001, CI: 0.002–0.49), hypertension (OR: 0.23, p = 0.04, CI: 0.057–0.930) and depression (OR: 0.12, p < 0.001, CI: 0.041–0.330) reduced inflammatory arthritis odds. White ethnicity and older age at HS onset were positively associated with inflammatory arthritis, while smoking, hypertension and depression were negatively associated. These findings suggest a distinct subset of HS patients with inflammatory arthritis that warrant further prospective studies. This study contributes to the understanding of inflammatory arthritis in HS patients and emphasises the importance of rheumatology referral during dermatologic clinic visits.