Search Results (225)

Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen frequently associated with delayed wound healing, particularly in chronic skin injuries. Its capability to form biofilms, secrete virulence factors, and the faculty to compete with other microorganisms makes it a major challenge in clinical wound management. Recent literature reveals different molecular and cellular mechanisms through which P. aeruginosa disrupts the wound healing process. Findings highlight that it interferes with key phases of healing by modulating host immune responses, degrading extracellular matrix components, and inhibiting keratinocyte migration. Its quorum-sensing systems regulate the expression of critical virulence factors such as exotoxin A, elastases, pyocyanin, and rhamnolipids. Additionally, the production of the biofilm matrix components alginate, and polysaccharides provide protection against host defenses and antibiotics. Interactions with other microorganisms, including antagonistic effects on Staphylococcus epidermidis and synergistic relationships with Staphylococcus aureus, modify the wound microbiota. Promising therapeutic alternatives have shown efficacy in disrupting biofilms and reducing virulence. These insights remark the importance of targeting both P. aeruginosa and its ecological interactions to enhance wound healing outcomes and develop more effective treatments. This review aimed to highlight the pathogenic role of P. aeruginosa and its interactions with other microbial species in the context of skin wound healing. Full article

The lung is increasingly recognized as an organ with dual endocrine and respiratory roles, participating in a complex bidirectional crosstalk with systemic hormones and local/paracrine activity. Endocrine and paracrine pathways regulate lung development, ventilation, immunity, and repair, while pulmonary cells express hormone receptors and secrete mediators with both local and systemic effects, defining the concept of the “endocrine lung”. This narrative review summarizes current evidence on the endocrine–pulmonary axis. Thyroid hormones, glucocorticoids, sex steroids, and metabolic hormones (e.g., insulin, leptin, adiponectin) critically influence alveologenesis, surfactant production, ventilatory drive, airway mechanics, and immune responses. Conversely, the lung produces mediators such as serotonin, calcitonin gene-related peptide, endothelin-1, leptin, and keratinocyte growth factor, which regulate vascular tone, alveolar homeostasis, and immune modulation. We also describe the respiratory manifestations of major endocrine diseases, including obstructive sleep apnea and lung volume alterations in acromegaly, immunosuppression and myopathy in Cushing’s syndrome, hypoventilation in hypothyroidism, restrictive “diabetic lung”, and obesity-related phenotypes. In parallel, chronic pulmonary diseases such as chronic obstructive pulmonary disease, interstitial lung disease, and sleep apnea profoundly affect endocrine axes, promoting insulin resistance, hypogonadism, GH/IGF-1 suppression, and bone metabolism alterations. Pulmonary neuroendocrine tumors further highlight the interface, frequently presenting with paraneoplastic endocrine syndromes. Finally, therapeutic interactions are discussed, including the risks of hypothalamic–pituitary–adrenal axis suppression with inhaled corticosteroids, immunotherapy-induced endocrinopathies, and inhaled insulin. Future perspectives emphasize mapping pulmonary hormone networks, endocrine phenotyping of chronic respiratory diseases, and developing hormone-based interventions. Full article

A fast-paced lifestyle contributes to heightened emotional stress, driving the demand for milder and safer cosmetic ingredients that can counteract stress-induced skin damage—a focus of cutting-edge research in the field. Aim: The aim was to elucidate the role and mechanistic basis of tea (Camellia sinensis) seed meal saponin (Sap) in regulating stress-induced sebum overproduction and inflammatory responses. Methods: The composition and chemical structure of Sap were analyzed using UV-vis absorption spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), and ultra-high-performance liquid chromatography–mass spectrometry (UHPLC-MS). In vitro models of cortisone-induced excessive lipid accumulation and the tumor necrosis factor-alpha (TNF-α)-stimulated inflammatory models were established on sebaceous gland cells (SZ95) and normal human epidermal keratinocytes (NHEKs), respectively. Cortisol and inflammatory cytokine secretion levels in cells were detected using ELISA. Additionally, the signaling pathways were revealed by Western blot (WB) and real-time quantitative polymerase chain reaction (RT-PCR). Results: Five saponins were identified in the Sap extract, all belonging to the oleanolic-acid-type pentacyclic triterpenes. Sap treatment significantly attenuated cortisone-induced cortisol secretion and lipid accumulation in SZ95 sebocytes. Mechanistically, Sap inhibited the 11β-HSD1/SREBP-1 pathway, which mediates its sebosuppressive effects, while concurrently down-regulating the mRNA expression of key downstream transcription factors and enzymes, including SREBP-1, FAS, and ACC. Additionally, Sap treatment significantly attenuated TNF-α-stimulated cortisol secretion and inflammatory cytokine (IL-1β, IL-6, and IL-8) production in NHEK cells through the inhibition of the 11β-HSD1/TLR2/NF-κB signaling pathway. Conclusion: Sap demonstrated dual inhibitory effects, suppressing both emotional-stress-induced sebum overproduction and inflammatory cytokines secretion. Full article

Inflammatory facial dermatoses (atopic dermatitis [AD], acne vulgaris, contact dermatitis, seborrheic dermatitis, rosacea, perioral dermatitis, and demodicosis, etc.) often profoundly impact patients’ appearance and psychological well-being. In this narrative review, we wanted to present the current knowledge on the role of skin microbiota in common facial dermatoses. Skin keratinocytes are the primary producers of antimicrobial peptides (AMPs) and express Toll-like receptors (TLRs), which stimulate the T helper (Th1) immune response, with the production of interferon (IFN). They can also produce certain pro-inflammatory cytokines, namely IL-1β, IL-18, IL-6, IL-10, and the tumor necrosis factor (TNF). In healthy infants, the bacterial skin microbiota is predominantly composed of Firmicutes (genera Staphylococcus and Streptococcus), as well as Actinobacteria, Proteobactera, and Bacteroidota. The genera Cutibacterium and Staphylococcus, which have antimicrobial effects and compete with pathogens for nutrients/ecological niches, coexist symbiotically on the skin and can reduce the expression of TLR2 and TLR4. In patients with AD, lesional/non-lesional skin was found to have increased colonization by Staphylococcus aureus which reduces effector T lymphocytes’ ability to produce cytokines, such as IL-17A and IFN-γ, leading to decreased AMP production and impaired skin microbiota immune functionality. In patients with rosacea, the overexpression of TLR2 may stimulate elevated pro-inflammatory cytokine production (IL-8, IL-1β, and TNF-α, etc.), exacerbating the inflammatory response. Also, increased colonization by Malassezia yeasts triggers a Th2 immune response and cytokine secretion (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, TNF-α, beta-defensin, IFN-γ, nitric oxide, and histamine), and participates in signaling pathways. Insight into these factors may further improve clinical approaches to patients with facial dermatoses. Full article

Snail slime (SS) is a natural secretion rich in bioactive components such as glycoproteins, hyaluronic acid, glycolic acid (GA), and antimicrobial peptides. GA, a key component of SS, is known for its exfoliative properties. This study investigates SS’s effects on keratinocytes (HaCaT) and endothelial cells (ECs), comparing its properties to those of GA. HaCaT cell viability and cytotoxicity, ROS release, and inflammation-related signaling (PI3K/Akt/NF-κB and COX-2 gene expression) were assessed. Extracellular matrix (ECM) remodeling was evaluated by gene expression of MMPs. In ECs, a preliminary evaluation of SS’s effect was conducted in terms of cell viability and migration. Results demonstrated that SS is well tolerated by keratinocytes whereas GA exhibits cytotoxicity, suggesting that SS’s natural composition mitigates GA’s adverse effects. SS induced a controlled, brief inflammatory response, via the PI3K/Akt/NF-κB pathway, unlike GA, responsible for stronger and sustained pro-inflammatory events. Additionally, SS, through the upregulation of MMPs, contributes to ECM remodeling. In ECs, SS preserves viability and also enhances migration, thus supporting wound healing. These findings highlight SS’s ability to balance pro-inflammatory events, making it a promising candidate for advanced dermatological applications, underscoring SS’s potential in modulating key cellular signaling pathways, and supporting its future therapeutic prospects in wound healing. Full article

Background: Secondary rejection remains a major obstacle in skin allografting. Some viruses, such as human herpesvirus and cytomegalovirus, evade immune detection through proteins like the unique short glycoprotein 11 (US11), which down-regulates major histocompatibility complex (MHC) class I expression. This study explores the use of recombinant US11 protein as a biopharmaceutical approach to reduce MHC-I expression and thus decrease alloreactivity in human primary keratinocytes. Methods: Human keratinocytes were treated with recombinant US11 protein, and MHC-I expression was assessed via Western blot and flow cytometry. To evaluate immunomodulatory effects, US11-stimulated keratinocytes were co-cultured with peripheral blood mononuclear cells (PBMCs), and interferon-gamma (IFN-γ) levels were measured by ELISA. Additionally, ex vivo human skin tissue was stimulated with US11 to assess long-term MHC-I modulation. Results: US11 treatment significantly reduced MHC-I surface expression in keratinocytes. Co-cultures showed decreased IFN-γ secretion, indicating lower T cell activation. Human skin tissue stimulated with US11 exhibited reduced MHC-I expression after 7 days. Conclusions: This proof-of-concept study suggests that recombinant US11 protein may serve as an effective biopharmaceutical to reduce keratinocyte immunogenicity. Further in vitro and in vivo studies are warranted to validate its potential for clinical application in skin transplantation. Full article

Wound healing is a complex process in which TGFβ plays a key role. Previous studies have shown that syringin, a phenylpropanoid glycoside present in lilac bark (Syringa vulgaris L.), stimulates TGFβ expression in human monocyte-derived macrophages in addition to inhibiting the secretion of pro-inflammatory cytokines. Here, we investigated the effect of syringin on migration, invasion, and TGFβ production, as well as the effect on the release of pro-inflammatory cytokines in human dermal fibroblasts (NHDF) and keratinocytes (HaCaT) and its mechanism of action. NHDF and HaCaT cells were treated with the tested compound (12.5–100 µM), and a scratch assay was performed. The effect of migration using modified Boyden chambers was analyzed. TGFβ and IL-6 release were also assessed using ELISA kits. Cell proliferation was assessed using MTT and BrdU incorporation tests, while cytotoxicity was assessed using a neutral red uptake test. Smad2 and Smad3 phosphorylation were assessed using Western Blotting. ACTA2, COL1A1, and TIMP3 expression was analyzed using qPCR. Cells treated with syringin showed an increase in invasion potential in the scratch assay. A significant increase in skin fibroblast migration through the porous membrane was also observed. Syringin increased TGFβ release and inhibited IL-6 release by NHDF and HaCaT cells. No effect of syringin on cell proliferation or cytotoxic effects was observed. Western blot analysis showed significant activation of Smad2 and Smad3 in the presence of syringin in NHDF cells, but not in HaCaT. Quantitative PCR analysis revealed a strong increase in ACTA2 and COL1A1 gene expression in fibroblast cells treated with syringin. The present study demonstrated that syringin present in S. vulgaris stem bark increased dermal fibroblasts and keratinocytes’ wound healing function through activation of cell migration. Full article

Atopic dermatitis (AD) is a chronic, relapsing inflammatory skin disorder affecting 10–20% of the population. In this study, we investigate the anti-inflammatory effect on the skin of eight compounds isolated from Digitalis purpurea L., using tumor necrosis factor-α (TNF-α)/interferon-γ (IFN-γ)-stimulated human keratinocytes (HaCaT cells) and a three-dimensional (3D) reconstructed human skin model. Among the tested compounds, desrhamnosyl acteoside exhibited the most potent activity, significantly reducing the secretion of pro-inflammatory cytokines (IL-6, IL-8) and chemokines (CCL17, CCL22), suppressing the expression of inflammatory proteins, and modulating key signaling pathways, including NF-κB, JAK2/STAT1, and MAPK. Notably, this is the first report demonstrating that desrhamnosyl acteoside simultaneously targets all three pathways, indicating a multi-modal mechanism distinct from conventional single-target approaches. In the 3D skin model, desrhamnosyl acteoside further exhibited barrier-protective effects by downregulating inflammatory mediators and upregulating epidermal differentiation markers such as involucrin and loricrin. These findings reveal a previously uncharacterized phytochemical with dual anti-inflammatory and barrier-restorative activities, supporting its potential as a novel therapeutic candidate for AD and other inflammatory skin diseases. 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

Exosomes, small extracellular vesicles secreted by various cell types, have gained significant attention in cancer investigations. Isolation and characterization of exosomes derived from DOK (dysplastic oral keratinocyte), SCC (squamous cell carcinoma) and HaCaT (normal skin keratinocyte) cell lines and microRNA profiling were conducted. Magnetic sorting was applied to obtain pure exosomes. Morphology and size were characterized by transmission electron microscopy and nanoparticle tracking analysis. Validation of membrane exosomal markers (CD9, CD63) was performed via Western blotting. MiR-21, miR-31, and miR-133 levels were analyzed in exosomes and parent cells by qPCR. Biological effects of the exosomes were tested by adding them to fibroblast cultures and determining the expression of relevant carcinogenesis markers by qPCR. Exosomes appeared as cup-shaped nano-sized particles, and there was no difference regarding particle diameter and concentration between the three types of exosomes. The oncogenic miR-21 was significantly upregulated both in SCC and SCC-derived exosomes compared to DOK and HaCaT cells and their respective exosomes. However, miR-31 unexpectedly showed the highest expression in normal cells and the lowest in HaCaT exosomes. MiR-133, the tumor suppressor miRNA, was downregulated in both SCC and DOK cells compared to normal (HaCaT) cells, while the opposite situation was observed in exosomes, with HaCaT cells showing the lowest levels of miR-133. The differences in exosome content were reflected in signaling pathway activation in exosome-treated fibroblasts, with SCC exosomes exerting the most potent effect on several cancer-related pathways, notably PIK3/AKT, PTEN, and NOTCH signaling cascades. Full article

Oxidative stress has been directly implicated in the pathogenesis of various skin disorders, making it a promising target for therapeutic intervention. Bauhinia forficata Link (BFL), commonly referred to as “plant insulin,” is well known for its antioxidant and antihyperglycemic properties; however, its potential role in skin protection remains unexplored. In this study, we investigated the protective effects of BFL against H₂O₂-induced oxidative stress and inflammation in HaCaT keratinocytes. The major phytochemical constituents of BFL were identified by high-performance liquid chromatography (HPLC). Its antioxidant capacity was evaluated using 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), oxygen radical absorbance capacity (ORAC), and superoxide dismutase (SOD). In an H₂O₂-induced oxidative stress model, we assessed intracellular reactive oxygen species (ROS) levels and apoptosis using flow cytometry. Cellular respiration was analyzed using a Seahorse XFp analyzer, while molecular mechanisms were examined by reverse transcription polymerase chain reaction (RT-PCR) and western blotting. Our results demonstrated that BFL significantly reduced intracellular ROS levels and apoptosis, primarily by activating the nuclear factor erythroid 2–related factor 2 (Nrf2)/PINK1 pathway, which promoted mitochondrial quality control and redox homeostasis. Additionally, BFL suppressed inflammatory responses by downregulating the nuclear factor-κB (NF-κB) signaling pathway and reducing the secretion of pro-inflammatory cytokines interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha (TNF-α). These findings suggest that BFL is a potent antioxidant and anti-inflammatory agent, with potential as an adjunctive therapy for oxidative stress-related skin conditions. Full article

Wild soybean (Glycine soja, GS) is a traditional medicine used to treat inflammation. In this study, the anti-atopic properties of GS leaf and stem extract on skin inflammation were evaluated in the Dermatophagoides farinae-extract-induced mouse model and keratinocytes. Oral administration of the GS extract reduced scratching, dermatitis score, transepidermal water loss, thickness of epidermis, inflammatory cell accumulation, and serum concentrations of thymic stromal lymphopoietin and immunoglobulin E. GS downregulated the expression of inflammatory gene markers of atopic dermatitis (AD), including interleukin (IL)-6; regulated on activation, normal T cell expressed and secreted (RANTES); thymus- and activation-regulated chemokine (TARC); and macrophage-derived chemokine (MDC) and upregulated the expression of filaggrin, a keratinocyte differentiation marker, in skin tissue. GS downregulated Janus kinase 1, signal transducer and activation of transcription (STAT) 1, and STAT3 pathways. Using ultra-performance liquid chromatography, we identified seven flavonoids in GS extract, including apigenin, epicatechin, genistein, genistin, daidzin, daidzein, and soyasaponin Bb. GS, apigenin, and genistein reduced the expression of IL-6, MDC, TARC, and RANTES and increased filaggrin via the downregulation of STAT3 phosphorylation in interferon-γ/tumor necrosis factor-α-stimulated keratinocytes. Our results suggest that GS leaf and stem extract ameliorates AD-like skin inflammation by regulating the immune response and restoring skin barrier function. Full article

Severe skin damage poses a significant clinical challenge, as limited availability of skin donors, postoperative skin defects, and scarring often impair skin function. Traditional two-dimensional (2D) nanofibers exhibit small pore sizes that hinder cellular infiltration, unable to simulate the three-dimensional (3D) structure of the skin. To address these issues, we developed 3D porous nanofiber scaffolds composed of polycaprolactone–polylactic acid–mussel adhesive protein (PLGA-PCL-MAP) using low-temperature electrospinning combined with nano-spray technology. Meanwhile, this 3D scaffold features high porosity, enhanced water absorption, and improved air permeability. The incorporation of mussel adhesive protein (MAP) further increased the scaffold’s adhesive properties and biocompatibility. In vitro experiments demonstrated that the 3D nanofiber scaffolds significantly promoted the adhesion, proliferation, and migration of epidermal keratinocytes (HaCaTs) and human fibroblasts (HFBs), while providing ample space for inward cellular growth. Successful co-culture of HaCaT and HFBs within the scaffold revealed key functional outcomes: HaCaTs expressed keratinocyte differentiation markers CK10 and CK14, while HFBs actively secreted extracellular matrix components critical for wound healing, including collagen I, collagen III, and fibronectin. This skin substitute with a composite structure of epidermis and dermis based on three-dimensional nanofiber scaffolds can be used as an ideal skin replacement and is expected to be applied in wound repair in the future. Full article

Background: Cannabis sativa L. (C. sativa) has a long history of medicinal use. Its inflorescences contain bioactive compounds like non-psychotropic cannabidiol (CBD), which is well known for its anti-inflammatory potential in skin conditions such as psoriasis, and psychotropic Δ-9-tetrahydrocannabinol (THC). Keratinocytes, the main cells in the epidermis, are crucial for regulating skin inflammation by producing mediators like IL-8 when stimulated by agents like TNFα. Methods: This study explores the anti-inflammatory effects of a standardized C. sativa extract (CSE) with 5% CBD and less than 0.2% THC in human keratinocytes challenged by TNFα. The aim of this study is to analyze the specific contributions of the main constituents of CSE to inflammatory responses in human keratinocytes by fractionating the extract and examining the effects of its individual components. Results: MTT assays showed that CSE was non-toxic to HaCaT cells up to 50 μg/mL. CSE inhibited NF-κB activity and reduced IL-8 secretion in a concentration-dependent manner, with mean IC₅₀ values of 28.94 ± 10.40 μg/mL and 20.06 ± 2.78 μg/mL (mean ± SEM), respectively. Fractionation of CSE into four subfractions revealed that the more lipophilic fractions (A and B) were the most effective in inhibiting NF-κB, indicating that cannabinoids and cannflavins are key contributors. Pure CBD is one of the most active cannabinoids in reducing NF-κB-driven transcription (together with THC and cannabigerol), and due to its abundance in CSE, it is primarily responsible for the anti-inflammatory activity. Conclusions: This study highlights CBD’s significant role in reducing inflammation in human keratinocytes and underscores the need to consider the synergistic interactions of several molecules within C. sativa extracts for maximum efficacy. Standardized extracts are essential for reproducible results due to the variability in responses. Full article

Atopic dermatitis (AD), a chronic inflammatory skin condition, is a common allergic disorder. The human skin, the largest organ, serves as the first barrier in protecting the body against various external threats. Human epidermal keratinocytes (HEKs) in the epidermal layer and human dermal fibroblasts (HDFs) in the dermis of the skin are implicated in AD-associated skin inflammation through the secretion of diverse inflammatory mediators, including chemokines. Sigesbeckia pubescens Makino (SP), a traditional Korean and Chinese herbal remedy, is used for treating inflammatory conditions. While several pharmacological effects of SP extract (SPE) have been documented, its specific inhibitory effect on AD-related skin inflammation remains unexplored. Hence, oral administration of SPE to NC/Nga mice reduced the severity of house dust mite extract-induced dermatitis, accompanied by lowered levels of serum inflammatory mediators, decreased epidermal thickness, reduced mast cell infiltration, and restoration of skin barrier function within skin lesions. In conclusion, SPE has demonstrated the ability to alleviate skin inflammation and protect the skin barrier and shows potential as a therapeutic option for AD. SPE inhibited proinflammatory chemokine production by modulating the Janus kinase (JAK) 2/signal transducer and activator of transcription proteins (STAT) 1/STAT3 signaling pathway in IFN-γ- and TNF-α-stimulated skin cells. Full article