Keratinocyte Cell Research Articles

Modulating the γ-ray Protection Properties of Melanin via a Highly Conjugated Catechol Structure.

Melanin is a dark pigment found in many organisms that interacts with various forms of electromagnetic radiation, such as X-rays, γ-rays, and Ultraviolet visible light, providing protection against radiation damage to the host. The mechanism by which melanin protects against ionizing radiation involves dissipating energy around the cell nucleus to form a perinuclear cap. Additionally, melanin reacts with the free radicals produced by the radiolysis of water, quenching reactive oxygen species. In this study, we introduced a conjugated monomer, hexahydroxytriphenylene (HHTP), which has a rigid planar structure, into selenomelanin. The aim was to increase the physical shielding ability of selenomelanin while increasing its free radical content. Our findings indicated that incorporating HHTP molecules into selenomelanin effectively increased the unpaired electron content of selenomelanin and protected immortalized human keratinocyte (HaCaT) cells from 10 Gy γ-rays exposure. Additionally, eumelanin supplemented with HHTP molecules demonstrated excellent biocompatibility and offered similar protection to HaCaT cells exposed to 10 Gy γ-rays at high concentrations. This study is important for optimizing the functionality of melanin through the modulation of its conjugated structure.

Is Silver a Precious Metal for G-Quadruplex Stabilization Mediated by Porphyrins?

Cancer is a leading cause of death, so continuous efforts into cancer therapy are imperative. In tumor cells, telomerase and oncogene activity are key points for uncontrolled cell growth. Targeting these processes with ligands that inhibit telomerase and/or reduce oncogene expression has been identified as a promising cancer therapy. This study evaluated the selectivity and affinity of the silverII complex of 5,10,15,20-tetrakis(N-methyl-4-pyridinium)porphyrin (AgTMPyP) to stabilize DNA sequences capable of forming G4 structures mimicking the telomeric and oncogene regions, using spectroscopic, biochemical methods and in vitro assays. The tetracationic silver complex was compared with the free base, H2TMPyP, and the zincII complex, ZnTMPyP. The results obtained from UV-Vis and fluorescence methods pointed to a great affinity and good selectivity of AgTMPyP to G4 structures, especially for the oncogene MYC. In general, an increase in the ability of the studied ligands for 1O2 generation when interacting with oncogenic and telomeric G4 sequences was found. The results of the PCR stop assays proved that AgTMPyP has the ability to inhibit Taq polymerase. Additionally, in vitro assays demonstrated that the silverII complex exhibits low cytotoxicity against HaCaT— an immortalized, non-tumorigenic, skin keratinocytes cell line—and, although nonexclusive, AgTMPyP shows nuclear co-localization.

Selective Lipophilization of Natural Phenolic Alcohols Induced by In Situ Choline Chloride-Based Natural Deep Eutectic Solvents.

In this scientific work, a novel and green method for selective lipophilization of EVOO's bioactive phenolic alcohols (PAs), namely, tyrosol, hydroxytyrosol, and its metabolite homovanillyl alcohol as fatty acid esters, is elucidated. The PAs have been employed as hydrogen bond donors in the formation of natural deep eutectic solvents (NADES) with choline chloride (ChCl). The fast and cheap esterification method by in situ formation of choline chloride-based deep eutectic solvents promotes the derivatization of PAs with various fatty acids as acylating agents in the absence of organic solvents and catalysts. Furthermore, given the growing interest in the application of NADES formed by bioactive molecules in the pharmacological and cosmetic fields, we analyzed the activity of antioxidant enzymes, superoxide dismutase, and glutathione S-transferase of three chemical formulations obtained after the formation of PA-oleate in the H2O2-treated HaCat human keratinocytes cell line, assessing also their toxicity via the MTT assay.

The Potential of Tecoma stans (Linn.) Flower Extract as a Natural Antioxidant and Anti-Aging Agent for Skin Care Products

Tecoma stans belongs to the Bignoniaceae family and possesses various pharmacological activities, including antimicrobial, anti-inflammatory, antifungal, antioxidant, and wound-healing activities. Although numerous studies have highlighted the beneficial effects of T. stans extracts, the impacts of different solvents on its biological activities, particularly its inhibitory effect on skin degradation enzymes (collagenase, elastase, and hyaluronidase assay), have not been reported. This study aims to explore the effects of different solvent extractions on the total phenolic and total flavonoid contents, antioxidant and anti-aging activities, and cytotoxicity. The most suitable extract was selected for incorporation into an anti-aging product. T. stans flowers were extracted using hexane, ethyl acetate, absolute ethanol, and deionized water through maceration. The aqueous extract yielded the highest extraction efficiency (40.73%), followed by absolute ethanol, ethyl acetate, and hexane. The phytochemical screening results revealed that all T. stans flower extracts contained phenolics, flavonoids, terpenoids, and alkaloids. Among the various solvents tested for T. stans flower extraction, absolute ethanol demonstrated the highest total phenolic content (24.10 ± 2.07 mg gallic acid equivalents (GAE)/g extract), followed by deionized water (20.83 ± 1.28 mg GAE/g extract). The highest total flavonoid content was observed in the ethyl acetate extract (205.11 ± 7.83 mg catechin equivalents (CE)/g extract), with ethanol showing a significantly lower concentration (140.67 ± 1.92 mg CE/g extract). In terms of antioxidant activity, the aqueous extract exhibited the most potent effects, with IC50 values of 0.600 ± 0.005 mg/mL for the DPPH• assay and 0.207 ± 0.001 mg/mL for the ABTS•+ assay. For anti-aging assays, the absolute ethanolic extract demonstrated the highest enzyme inhibition activity at 1 mg/mL, with collagenase, elastase, and hyaluronidase inhibition rates of 89.49% ± 2.96%, 94.61% ± 2.33%, and 82.56% ± 2.27%, respectively. Moreover, at a concentration of 50 µg/mL, the absolute ethanolic extract exhibited lower cytotoxicity, with human keratinocyte (HaCaT) cell viability of 78% ± 8.47%, which was significantly higher than that of the other extracts. An anti-aging gel containing 0.05% w/w of the ethanolic T. stans extract demonstrated physical and physicochemical stability during three months of storage at ambient temperatures, 4 °C, 45 °C, as well as after six cycles of heating/cooling tests. These findings suggest that the ethanolic extract of T. stans flower has potential as a safe and effective anti-aging agent for cosmeceutical products.

Assessment of in vitro dynamics of pathogenic environmental Acanthamoeba T4 and T9 genotypes isolated from three recreational lakes in Klang Valley, Malaysia over the HaCaT cell monolayer

ABSTRACT Free-living amoebae of the genus Acanthamoeba are causative agents of keratitis and amoebic encephalitis. They are widely found in various ecological environments. Therefore, the present study brings results that can help to better understand the genotypes of the environmental isolates and their pathogenicity. This study procured 26 Acanthamoeba isolates from three recreational lakes in 2022. Polymerase chain reaction amplification was performed on positive Acanthamoeba samples. The thermotolerance, osmotolerance, and cytopathogenicity in human keratinocyte (HaCaT) cells of the samples were also evaluated. The phylogenetic analysis demonstrated that 12 isolates were of genotype T4, two (T9), six (T17), four (T8), and one each from T5 and T11. The thermo- and osmotolerance assays indicated that eight Acanthamoeba samples were potentially pathogenic. Two T4 and one T9 genotype also recorded 33-, 42-, and 133-kDa serine-type proteases, respectively. The HaCaT cell monolayer revealed that three T4 and one T9 samples achieved cytopathic effects within the 50–100% range, hence significantly cytotoxic. The lactate dehydrogenase secretion results demonstrated that three (T4) and one (T9) sample exhibited exceptional toxicity (over 40%) compared to the other samples. The responses of Acanthamoeba members with similar genotypes to pathogenicity indicator assays varied considerably, rendering correlation of pathogenicity with specific genotypes challenging.

Dermatological Nanotechnology: Gelatin films with O/W emulsions for skin lesion repair.

The development of films, scaffolds, hydrogels, and other innovations based on biopolymers for the treatment of skin injuries is on the rise. Therefore, it is important to focus on their functionality, influence on human use, and environmental impact. This work investigates the antimicrobial capacity of gelatin films that incorporate O/W emulsions encapsulating bactericidal and healing active ingredients (EA). Their biocompatibility was evaluated in vitro in human skin keratinocyte and murine fibroblast cell cultures, as well as in vivo using the zebrafish model. Finally, its potential to heal wounds was assessed through a keratinocyte cell migration assay. The EA films exhibited antimicrobial activity against Pseudomonas aeruginosa and Staphylococcus aureus. The films were biocompatible with monolayer cultures, without affecting cell viability, metabolic activity, or membrane integrity. The films did not exhibit general toxicological effects in zebrafish nor specific organ toxicity in the heart, liver, or brain. Further, the EA films promoted keratinocyte migration in the wound healing assay. In conclusion, the films could be used as a potential treatment for various types of skin injuries, being safe for both potential human application and the environment after use and disposal.

Dental pulp stem cells promote malignant transformation of oral epithelial cells through mitochondrial transfer.

Oral epithelial dysplasia includes a range of clinical oral mucosal diseases with potentially malignant traits. Dental pulp stem cells (DPSCs) are potential candidates for cell-based therapies targeting various diseases. However, the effect of DPSCs on the progression of oral mucosal precancerous lesions remains unclear. Animal experiments were conducted to assess the effect of human DPSCs (hDPSCs). We measured the proliferation, motility and mitochondrial respiratory function of the human dysplastic oral keratinocyte (DOK) cells cocultured with hDPSCs. Mitochondrial transfer experiments were performed to determine the role mitochondria from hDPSCs in the malignant transformation of DOK cells. hDPSCs injection accelerated carcinogenesis in 4NQO-induced oral epithelial dysplasia in mice. Coculture with hDPSCs increased the proliferation, migration, invasion and mitochondrial respiratory function of DOK cells. Mitochondria from hDPSCs could be transferred to DOK cells, and activated mTOR signaling pathway in DOK cells. Our study demonstrates that hDPSCs activate the mTOR signaling pathway through mitochondrial transfer, promoting the malignant transformation of oral precancerous epithelial lesions.

Pulsed Electric Field Pretreatment Enhances the Enzyme Hydrolysis of Baker’s Yeast

Baker’s yeast is a key starting material for producing extracts with diverse compositions and applications. This study investigates the effect of pulsed electric field (PEF) pretreatment, which induces irreversible electropermeabilization, on the enzymatic hydrolysis of yeast. Cell suspensions were exposed to monopolar rectangular pulses in a continuous flow system followed by 4 h of incubation with Alcalase at concentrations of 0.2% and 0.5%. PEF pretreatment significantly improved enzymatic hydrolysis, with maximum intracellular content recovery under electrical conditions resulting in outlet temperatures of 56–58 °C. The released protein reached 163.7 ± 13 mg per gram of dry cell weight (DCW). SDS-PAGE analysis showed that the extracts predominantly contained peptides with molecular masses below 4.7 kDa. The phenolic content was comparable to that of cell lysates obtained after mechanical disruption. The free α-amino nitrogen content and total antioxidant activity reached 218.2 ± 26 mg/gDCW and 53.4 ± 4.6 mg TE/gDCW, respectively, representing 3.2-fold and 2.65-fold increases compared to cell lysates. The hydrolysates from PEF-pretreated cells demonstrated a positive effect on the proliferation of the human keratinocyte cell line HaCat. The obtained data lead to the conclusion that PEF pretreatment is a promising approach to enhance the production of yeast hydrolysates with various applications.

Effects of Arborvitae (Thuja plicata) Essential Oil on Cervical Cancer Cells: Insights into Molecular Mechanisms.

This study aimed to assess the effects of AEO in an in vitro model of cell lines derived from cervical cancer-namely, HeLa and SiHa-by screening for AEO's cytotoxic properties and examining its influence on the modulation of gene expression. Cervical cancer stands as a prevalent global health concern, affecting millions of women worldwide. The current treatment modalities encompass surgery, radiation, and chemotherapy, but significant limitations and adverse effects constrain their effectiveness. Therefore, exploring novel treatments that offer enhanced efficacy and reduced side effects is imperative. Arborvitae essential oil, extracted from Thuja Plicata, has garnered attention for its antimicrobial, anti-inflammatory, immunomodulatory, and tissue-remodeling properties; however, its potential in treating cervical cancer remains uncharted. The objective of this study was to delve into the molecular mechanisms induced by arborvitae essential oil in order to learn about its anticancer effects on cervical cancer cell lines. The methods used in this study were assessments of cell viability using WST-1 and annexin V- propidium iodide, mRNA sequencing, and subsequent bioinformatics analysis. The findings unveiled a dose-dependent cytotoxic effect of arborvitae essential oil on both HeLa and SiHa cell lines. Minor effects were observed only at very low doses in the HaCaT non-tumorigenic human keratinocyte cells. RNA-Seq bioinformatics analysis revealed the regulatory impact of arborvitae essential oil on genes enriched in the following pathways: proteasome, adherens junctions, nucleocytoplasmic transport, cell cycle, proteoglycans in cancer, protein processing in the endoplasmic reticulum, ribosome, spliceosome, mitophagy, cellular senescence, and viral carcinogenesis, among others, in both cell lines. It is worth noting that the ribosome and spliceosome KEGG pathways are the most significantly enriched pathways in HeLa and SiHa cells. Arborvitae essential oil shows potential as a cytotoxic and antiproliferative agent against cervical cancer cells, exerting its cytotoxic properties by regulating many KEGG pathways.

Therapeutic potential of sulforaphane throughout suppression of antimicrobial peptides in psoriatic HaCaT keratinocyte cells

Therapeutic potential of sulforaphane throughout suppression of antimicrobial peptides in psoriatic HaCaT keratinocyte cells

Fabrication of Bioactive Helix aspersa Extract-Loaded Chitosan-Based Bilayer Wound Dressings for Skin Tissue Regeneration.

In recent years, there has been a notable shift toward exploring plant and animal extracts for the fabrication of tissue engineering structures that seamlessly integrate with the human body, providing both biological compatibility and physical reinforcement. In this particular investigation, we synthesized bilayer wound dressings by incorporating snail (Helix aspersa) secretions, comprising mucus and slime, into chitosan matrices via lyophilization and electrospinning methodologies. A nanofiber layer was integrated on top of the porous structure to mimic the epidermal layer for keratinocyte activity as well as acting as an antibacterial barrier against possible infection, whereas a porous structure was designed to mimic the dermal microenvironment for fibroblast activity. Comprehensive assessments encompassing physical characterization, antimicrobial efficacy, in vitro bioactivity, and wound healing potential were conducted on these bilayer dressings. Our findings revealed that the mucus and slime extract loading significantly altered the morphology in terms of nanofiber diameter and average pore size. Snail extracts loaded on a nanofiber layer of bilayer dressings showed slight antimicrobial activity against Staphylococcus epidermidis and Escherichia coli. An in vitro release study of slime extract loaded in the nanofiber layer indicated that both groups 1 and 2 showed a burst release up to 6 h, and a sustained release was observed up to 96 h for group 1, whereas slime extract release from group 2 continued up to 72 h. In vitro bioactivity assays unveiled the favorable impact of mucus and slime extracts on NIH/3T3 fibroblast and HS2 keratinocyte cell attachment, proliferation, and glycosaminoglycan synthesis. Furthermore, our investigations utilizing the in vitro scratch assay showcased the proliferative and migratory effects of mucus and slime extracts on skin cells. Collectively, our results underscore the promising prospects of bioactive snail secretion-loaded chitosan constructs for facilitating skin regeneration and advancing wound healing therapies.

Development of dihydrooxyresveratrol-loaded nanostructured lipid carriers for safe and effective treatment of hyperpigmentation

Hyperpigmentation, a dermatological concern caused by increased melanin production, affects many people worldwide. Traditional skin-brightening products target inhibition of cellular tyrosinase activity but often contain harmful toxicants. Oxyresveratrol (OXR) is a robust tyrosinase inhibitor, but its instability, poor water solubility, and low skin permeation limit its use. This study aimed to overcome these challenges by modifying OXR to dihydrooxyresverstrol (DHO) and encapsulating both compounds into nanostructured lipid carriers (NLCs). The developed NLCs loaded with OXR (OXR-NLC) and DHO (DHO-NLC) achieve desirable physicochemical properties, high percentages of entrapment efficiency, and stability for at least three months during 4–40 ℃ of storage. DHO itself and NLC formulation of OXR dramatically enhanced the photostability of OXR. Additionally, NLC formulations significantly promoted controlled release and facilitated penetration through the skin-like hydrophobic membrane of OXR and DHO. Importantly, these NLC formulations exhibited no cytotoxicity on human keratinocyte cells up to 500 µg/mL and effectively reduced melanogenesis in B16F10 cells. Our findings indicate that DHO-loaded NLC offers a promising strategy for developing cosmeceutical products to address hyperpigmentation and promote skin lightening.

Stannous fluoride protects gingival keratinocytes against infection and oxidative stress by Porphyromonas gingivalis outer membrane vesicles

ObjectiveTo determine whether outer membrane vesicles (OMVs) of the periodontal pathogen Porphyromonas gingivalis (P. gingivalis) can infect gingival keratinocytes and stimulate reactive oxygen species (ROS) production, and to assess whether stannous fluoride (SnF2), stannous chloride (SnCl2) or 0.454% SnF2 toothpaste diluents can inhibit OMV infection.MethodsOMVs were isolated from P. gingivalis culture and their morphology was characterized using scanning electron microscopy and transmission electron microscopy. OMVs were harvested, separated from parent bacteria, labeled with fluorescent probes, and added to proliferating gingival keratinocytes. Infection was monitored by measuring uptake of fluorescence. Free radicals and ROS were quantified by adding a separate CellROX fluorescent probe following 24 h incubation with OMVs, and automated fluorescence imaging was used to assess ROS generation rates. A dose response range of SnF2 and SnCl2 concentrations as well as 0.454% SnF2 toothpaste dilutions were added to OMVs to examine their potential to neutralize OMV infectivity and protect gingival keratinocytes from development of oxidative stress. The mechanism of SnF2 inhibition of OMV infection was studied by binding SnF2 with purified lipopolysaccharides (LPS) from the bacterial culture and examining the binding of stannous to LPS using mass spectrometry.ResultsLarge numbers of OMVs were formed in P. gingivalis culture medium. They were purified along with isolating soluble LPS. Fluorescence imaging revealed that OMVs infected gingival keratinocytes and promoted oxidative stress in a dose-dependent manner. SnF2, SnCl2, and SnF2 toothpaste inhibited OMV infectivity (p < 0.05) and likewise protected gingival keratinocytes from oxidative stress (p < 0.05). Stannous precipitated LPS and OMVs from solution, forming insoluble aggregates easily isolated by centrifugation. Mass spectroscopic analysis revealed that stannous was bound to LPS in a one-to-one molecular equivalent ratio.ConclusionSnF2 not only kills bacteria, but also inhibits bacterial virulence factors, such as LPS and OMVs. SnF2, SnCl2 and stannous-containing toothpastes can precipitate OMVs and LPS to in principle protect gingival keratinocyte cells from infection leading to inflammation and oxidative stress.

ARHGAP29 promotes keratinocyte proliferation and migration in vitro and is dispensable for in vivo wound healing.

RhoA GTPases play critical roles in actin cytoskeletal remodeling required for controlling a diverse range of cellular functions including cell proliferation, adhesion, migration and changes in cell shape, all required for cutaneous wound healing. RhoA cycles between an active GTP-bound and an inactive GDP-bound form, a process regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). ARHGAP29 is a GAP expressed in skin keratinocytes and is decreased in the absence of interferon regulator factor 6, a critical regulator of cell proliferation, migration, and wound healing. However, the role for ARHGAP29 in keratinocyte biology is unknown. We generated ARHGAP29 knockdown keratinocyte cell lines and show they displayed increased filamentous actin, phospho-myosin regulatory light chain, cell area and population doubling time. Furthermore, we found that ARHGAP29 knockdown keratinocytes displayed significant delays in scratch wound closure in both single and collective cell migration conditions; these delays were rescued by both adding back ARHGAP29 or adding a ROCK inhibitor to ARHGAP29 knockdown cells. In vivo, however, Arhgap29 heterozygotes or keratinocyte-specific knockouts showed on-time wound healing. These data demonstrate that ARHGAP29 is required for keratinocyte morphology, proliferation and migration in vitro but is dispensable during wound healing in vivo.

Photoprotective and bioinspired cerium-encapsulating lignin nanocapsules for multifunctional UV protection applications

Herein, Kraft lignin (KL) was used to encapsulate cerium oxide to synthesize a sunscreen with broad-spectrum sun protection factor (SPF), reactive oxygen species (ROS) scavenging, and antiphotoaging properties. Cerium encapsulated kraft lignin nanoparticles (K@CeNP) displayed the smallest zeta-average size of 93 nm, radical scavenging activity (RSA%) of 99 % at 500 µg/mL, and superior UV-blocking performance in both UVA and UVB regions. The successful encapsulation of cerium oxide within KL was also evaluated by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analyses. The cytotoxicity, UVA-induced photoprotective assay, UVA-induced oxidative stress and antiphotoaging were accessed on human keratinocyte cell lines (HaCaT) and human dermal fibroblasts (HDFs). The UVA-induced photoprotective effect and ROS level was analysed by exposing HaCat and HDFs to UVA radiation levels of 1000 mJ/cm2.The biocompatibility and UVA-induced cell viability of K@CeNP were much higher than those of K-LNP at all tested concentrations. The in-vitro ROS level was assessed by a DCF-DA assay while the antiphotoaging-activity was analysed by the senescence associated- Beta gal (SA- β gal) activity. Immediately after irradiation, K@CeNP showed a pronounced effect, reducing ROS by 77 % at 80 µg/mL in comparison to UVA control group. In addition, treatment with K@CeNP led to significant reduction in the SA- β gal activity. These findings highlight the applicability of lignin-based sunscreen that offers multifunctional benefits, effectively protecting the skin against UV rays while providing antioxidant and antiphotoaging benefits.

Anti-glycative effects of asiatic acid in human keratinocyte cells

Anti-glycative effects of asiatic acid in human keratinocyte cells

The Effect of Low-Frequency Magnetic Fields with Low Induction and Red LED Light on Keratinocyte Biological Activity-An In Vitro Research Model.

For several decades, there has been growing interest in the influence of low-frequency magnetic fields (LFMFs) and red LED light on the healing process. Keratinocytes are cells that play a significant role in the process of wound healing and tissue regeneration. A human keratinocyte cell line (HaCaT) was exposed to an LFMF with low induction (180-195 Hz; 60 µT, magnetostimulation), red LED light (630 nm; 300 mW, LED therapy), and their combined action (magneto-LED therapy) in in vitro culture conditions. On day 4 and 8 of the experiment, the following parameters were determined: adhesion/proliferation, adenylate kinase (AK), nitric oxide (NO), cytokines (IL-1β, IL-6, IL-8, IL-10, IL-12p70, TNF-α), metalloproteinases (MMP-2, MMP-9), and collagen IV. It was shown that magnetostimulation caused an increase in keratinocyte adhesion/proliferation and IL-8 secretion and a decrease in IL-12 secretion. The LED therapy resulted in a transient increase in the secretion of NO and cytokines IL-1, IL-12, and IL-6 in keratinocytes. The use of magneto-LED therapy resulted in an increase in keratinocyte adhesion/proliferation, the secretion of cytokines IL-6 and IL-8, and NO with a simultaneous decrease in MMP-9 secretion. The results of our studies showed that the action of an LFMF with low-induction and LED light on keratinocytes can modulate the biological activity of keratinocytes towards improving the skin healing process.

Moisturizing and antioxidant factors of skin barrier restoring cream with shea butter, silkflo and vitamin E in human keratinocyte cells.

Moisturizers are integral to daily skincare routines, reflecting the increasing trend among people towards cosmetic products, particularly for skin care. They significantly contribute to preserving skin health, particularly by regulating the epidermal barrier and moisture levels within the skin. This study aims to explore the moisturizing and antioxidant effect of skin barrier restoring cream Moiz MM (MZ) with shea butter, silkflo and vitamin E by investigating its protective effect against oxidative stress-induced cellular damage and therapeutic mechanisms in human keratinocytes cells (HaCaT). The invitro antioxidant activity of MZ was evaluated by DPPH, ABTS and NO assays. For the cell culture study, HaCaT cells were cultured and stimulated using H2O2 and then treated with different concentrations of MZ. Then, it was subjected to DCFH-DA staining, reverse transcriptase PCR and western blot analysis for the evaluation of various skin-moisture-related components in human keratinocyte cells. Type I procollagen was examined using ELISA technique. The results highlighted that oxidative stress in HaCaT cells decreased type I procollagen synthesis, while MZ treatment significantly increased the synthesis. Moreover, the viability of HaCaT cells was not affected in the presence of MZ, which demonstrates its non-toxic effect. Furthermore, MZ can counteract H2O2-mediated oxidative stress by enhancing the antioxidant enzyme activity such as superoxide dismutase and catalase, and decrease reactive oxygen species generation in skin cells. Additionally, MZ greatly promotes hyaluronic acid production by enhancing the expression of the hyaluronic acid synthase-1 gene and Aquaporin 3 protein. This study suggests that MZ has the potential to serve as a moisturizing and antioxidant skincare formula.

Comparison of Different Keratinocyte Cell Line Models for Analysis of NLRP1 Inflammasome Activation.

The NLRP1 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-1) inflammasome is the most important inflammasome in human keratinocytes. It plays a crucial role in regulating innate immunity in the skin. This study aimed to evaluate NLRP1 inflammasome activation and the corresponding levels of detection in different keratinocyte cell lines to identify a suitable in vitro model for analyzing inflammasome activation in keratinocytes. We compared NLRP1 inflammasome activation, expression, and cell death among primary keratinocytes and immortalized keratinocyte cell lines HaCaT, HaSKpw, and SVTERT upon stimulation with ultraviolet B (UVB) irradiation or talabostat. The effects of both NLRP1 inducers on cell death and the modification of NLRP1 molecules were examined using fluorescence-activated cell sorting analysis, Western blotting, and an enzyme-linked immunosorbent assay. The key inflammasome components had varied expression levels among the keratinocyte cell models, with the highest expression observed in primary keratinocytes. Moreover, our data showed that both UVB and talabostat triggered cell death, and NLRP1 inflammasome activation was readily detected in primary keratinocytes but not in the analyzed immortalized keratinocyte cell lines. Therefore, we do not recommend the use of the immortalized keratinocyte cell lines HaCaT, HaSKpw, and SVTERT for analyzing inflammasome activation in keratinocytes; we strongly recommend the use of primary keratinocytes for these studies.

Novel Insights Into the Ultrastructural and Immunofluorescence Characteristics of Limb Skin in the Red-Eared Slider Turtle (Trachemys scripta elegans).

The red-eared slider turtle, a species facing environmental challenges and habitat loss, exhibits a complex skin architecture that is crucial for its adaptation and survival. Our study aims to provide a comprehensive characterization of the turtle's skin structure and to elucidate the distribution and localization of its various cellular components, with a focus on understanding the skin's role in adaptation and ecological interactions. To achieve these goals, we employed light microscopy, transmission electron microscopy (TEM), and comprehensive immunofluorescence using 10 specific antibodies. The forelimb skin displays large- and moderate-sized scales with variations in color, including dark, yellow, and gray hues, likely contributing to camouflage and protection. The skin consists of corneous material, the epidermis, the dermis, and the hypodermis. The stratum basalis, stratum spinosum, and peri-corneous layer constitute the three distinct layers of the epidermis. There are four distinct types of chromatophores, including melanocytes located in the epidermis, while melanophores, xanthophores, and iridophores are found within the dermal layer. The skin also exhibits well-developed peripheral nerves, blood vessels, and subcutaneous muscles. Immunofluorescence staining further elucidates the distribution and localization of various skin cells. E-cadherin and CK14 are strongly expressed in the epidermal layers, excluding the corneous material. E-cadherin surrounds keratinocyte cells in the epidermis, facilitating cell-cell adhesion, while CK14 is present inside the keratinocyte cells, contributing to their internal structural integrity. Sox10 and CD117 identify the four chromatophore types, with Melan-A specifically detecting only melanocytes and melanophores and not labeling xanthophores and iridophores. Tom20 is used to detect mitochondrial distribution and intensity in the skin, revealing a high density of mitochondria in all epidermal layers, especially in melanocytes and melanophores, compared to xanthophores and iridophores. Numerous telocytes, spindle-shaped with extensions called telopods, are detected in the dermis using CD34, PDGFRα, and vimentin. The skin of the red-eared slider also shows abundant myofibroblasts and well-developed vascularization, with numerous blood vessels detected using α-SMA. This novel study offers an in-depth examination of the limb skin of the red-eared slider through the use of 10 distinct antibodies, uncovering the intricate interactions among its cellular components and providing valuable insights into its anatomical structure and physiological adaptations. Our findings contribute to a better understanding of the turtle's skin, which may aid in its conservation and management.