Mouse Skin Tissue Research Articles

Effects of Skin Environmental Changes by Steam Towel, Ethanol, l-Menthol and Carpronium on the Drug Behavior in the Minoxidil Nanoparticles-applied Mice

We previously designed the formulation containing minoxidil (MXD) nanoparticles (MXD-NPs), and found that the MXD-NPs can mainly deliver MXD into hair bulbs via hair follicles pathway, and that the therapeutic efficiency for hair growth is higher in comparison with the formulation containing dissolved MXD. In this study, we investigated whether the skin environmental changes by the treatment of steam towel, ethanol, l-menthol and commercially available (CA) carpronium affect the drug behavior in the MXD-NPs-applied mice. The steam towel, ethanol, l-menthol and CA-carpronium were pre-treated 3 min before MXD-NPs application, and the MXD content in the hair bulge, bulb, skin tissue and blood of mice were measured 4 h after MXD-NPs application. No significant difference of MXD levels in the blood was observed by the pre-treatment of steam towel, ethanol, l-menthol and CA-carpronium. On the other hand, the pre-treatment of steam towel and l-menthol enhanced the MXD levels in hair bulge and/or bulb. Although, the MXD levels in hair bulge and bulb were not changed by the pre-treatment of ethanol, the MXD levels in skin tissue was higher than that of saline-pre-treated group (control). The MXD levels in hair bulge, bulb and skin tissue of mice pre-treated with CA-carpronium were remarkably higher in comparison with control. In conclusion, we showed that the changes in skin environment by the steam towel, ethanol, l-menthol and CA-carpronium affected the absorption of MXD-NPs, and these increased MXD levels in the hair bulb and blood by the combination may enhance the therapeutic efficiency without side effects.

HPLC/QTOF-MS metabolomics analysis applied to identify skin biomarkers of UVC-induced skin injury in mice and preventive effects of abietic acid

Abietic acid (AA) is a main constituent from pine resin, which has definite therapeutical effects for treating skin ulcers and tumor. Here, we explored the metabolome changes in skin tissues of mice with UVC-induced skin injury treated with AA by a HPLC-QTOF-MS/MS method. Model mice were induced with UVC irradiation. Skin histopathological changes were examined by routine HE staining. Metabolomic analysis technology and pattern recognition statistical method were applied to analyze the metabolites in the skin tissues of mice to study the therapeutic effect of AA on UVC-induced skin injury in mice. Ceramides, sphingosines, glycyl-L-glutamine, dihydroorotic acid, adenosine, dCMP and lyso-phosphatidylcholines can be used as biomarkers of UVC-induced skin injury. AA can improve the pathological tissue from the pathway of skin lipid and purine pyrimidine metabolism to achieve the therapeutic effect. AA can effectively treat UVC-induced skin injury in mice.

Cynanoside F Controls Skin Inflammation by Suppressing Mitogen-Activated Protein Kinase Activation.

Atopic dermatitis (AD) is a chronic inflammatory skin disease accompanied by severe itching and dry skin. Currently, the incidence of AD due to excessive activation of immune cells by various environmental factors is increasing worldwide, and research on inflammatory response inhibitors with fewer side effects is continuously needed. Cynanoside F (CF) is one of the pregnane-type compounds in the root of Cynanchum atratum, an oriental medicinal herb that has been shown to have antioxidant, antitumor, and anti-inflammatory effects. Although CF has been isolated as a component in Cynanchum atratum, the scientific role of CF has not yet been explored. In this study, we evaluated the effect of CF on AD and revealed the mechanism using in vitro and in vivo experimental models. CF significantly reduced lipopolysaccharide (LPS)-induced protein expression levels of interleukin-1β (IL-1β), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2), which are important proinflammatory mediators in the RAW264.7 macrophage cell line. CF did not inhibit the nuclear factor-kappa B (NF-κB) signaling activated by LPS but significantly reduced the phosphorylation of mitogen-activated protein kinases (MAPKs), such as p38 MAPK, JNK, and ERK. CF consistently inhibited the activity of the activator protein-1 (AP-1) transcription factor, a downstream molecule of MAPK signaling. In addition, in an experiment using an oxazolone-induced AD mouse model, the CF-treated group showed a marked decrease in epidermal thickness, the number of infiltrated mast cells, and the amount of histamine. The mRNA levels of IL-1β, interleukin-4 (IL-4), and thymic stromal lymphopoietin (TSLP) were consistently lowered in the group treated with CF. Moreover, the phosphorylation of c-Jun and c-Fos protein levels, which are the AP-1 components, were lowered in the skin tissues of CF-treated mice. These results provide the first evidence that CF has an inhibitory effect on AD and suggest the possibility of CF being developed as a potential therapeutic agent for AD.

Establishment of a humanized animal model of systemic sclerosis in which T helper-17 cells from patients with systemic sclerosis infiltrate and cause fibrosis in the lungs and skin

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by inflammation, microangiopathy, and progressive fibrosis in the skin and internal organs. To evaluate the pathophysiologic mechanisms and efficacies of potential therapeutics for SSc, a preclinical model recapitulating the disease phenotypes is needed. Here, we introduce a novel animal model for SSc using immunodeficient mice injected with peripheral blood mononuclear cells (PBMCs) from SSc patients. Human PBMCs acquired from SSc patients and healthy controls were transferred into NOD.Cg-PrkdcscidIl2rgtm1Wjl (NSG) mice with concurrent bleomycin injection. Blood, skin, and lung tissues were acquired and analyzed after PBMC engraftment. In addition, we investigated whether the humanized murine model could be used to assess the efficacy of potential therapeutics for SSc. Human PBMCs from SSc patients and healthy controls were engrafted into the blood, skin, and lung tissues of NSG mice. Histological analysis of affected tissues from mice treated with SSc PBMCs (SSc hu-mice) demonstrated substantial inflammation, fibrosis and vasculopathy with human immune cell infiltration and increased expression of IL-17, TGF-β, CCL2, CCL3, and CXCL9. The proportions of circulating and tissue-infiltrating T helper 17 (Th17) cells were elevated in SSc hu-mice. These cells showed increased expression of CXCR3 and phosphorylated STAT3. SSc hu-mice treated with rebamipide and other potential Th17-cell-modulating drugs presented significantly reduced tissue fibrosis. Mice injected with patient-derived PBMCs show promise as an animal model of SSc.

Regulatory mechanism of deferoxamine on macrophage polarization and wound healing in mice with deep tissue injury

Regulatory mechanism of deferoxamine on macrophage polarization and wound healing in mice with deep tissue injury

Adipose-derived stem cells-derived exosomes facilitate cutaneous wound healing by delivering XIST and restoring discoidin domain receptor 2

BackgroundAdipose-derived stem cells (ADSCs) and their derived exosomes (ADSC-Exos) have shown potential functions in tissue repair. This study focuses on the effects of ADSCs-Exos on cutaneous wound healing and the potential involvement of the long non-coding RNA (lncRNA) XIST/microRNA-96-5p (miR-96-5p)/discoidin domain receptor 2 (DDR2) axis. MethodsExos were isolated from the ADSCs and identified. A mouse model of full-thickness skin wounds was established. The mice were treated with ADSC-Exos to evaluate the function of ADSC-Exos in wound healing. Mouse dermal fibroblasts (MDFs) were co-cultured with the ADSC-Exos for in vitro experiments. The most differentially expressed lncRNAs in mouse skin tissues after ADSC-Exo treatment were screened by microarray analysis. The downstream molecules were analyzed by bioinformatics tools. Gain- and loss-of-function studies were performed to examine the functions of the XIST/miR-96-5p/DDR2 axis in wound healing. ResultsADSC-Exos facilitated wound healing in mice, reduced inflammatory infiltration, and increased collagen deposition in the wound skin tissues. In vitro, the ADSC-Exos promoted proliferation, migration of the MDFs. XIST was the most upregulated lncRNA in MDFs after ADSC-Exo treatment. Downregulation of XIST suppressed the promoting role of ADSC-Exos in wound healing. XIST bound to miR-96-5p to restore the expression of DDR2 mRNA. Either silencing of miR-96-5p or overexpression of DDR2 restored the promoting functions of ADSC-Exos in proliferation and migration of MDFs. ConclusionThis study demonstrates that ADSC-Exos-carried XIST accelerates cutaneous wound healing through suppressing miR-96-5p and restoring the DDR2 expression.

Single-cell sequencing reveals the antifibrotic effects of YAP/TAZ in systemic sclerosis

Systemic sclerosis (SSc) is a heterogeneous disease with skin fibrosis. Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) is associated with fibrotic response. This work attempted to determine the precise mechanism of YAP/TAZ in SSc. Single-cell sequencing (scRNA-seq) was used to analyse the differential gene expression between SSc patients and healthy volunteers, showing that the YAP/TAZ signalling pathway was enriched in the fibroblasts of SSc patients. Subsequently, enzyme-linked immunosorbent assay and immunohistochemical analyses were conducted to examine the levels of YAP and TAZ in mild and severe SSc patients. YAP and TAZ were highly expressed in the serum and skin tissues of mild and severe SSc patients, especially severe SSc patients. Additionally, an SSc mouse model was induced by bleomycin, and the impacts of YAP/TAZ knockdown on the pathological changes in skin and lung tissues were detected by haematoxylin and eosin staining and Masson staining. Knockdown of YAP and TAZ inhibited α-SMA mRNA and protein expression in skin and lung tissues of SSc mice. Inhibition of YAP and TAZ reduced skin inflammation and thickness and repressed lung inflammation and fibrosis in SSc mice. Importantly, knockdown of YAP and TAZ synergistically inhibited inflammation and fibrosis in skin and lung tissues in SSc mice. In conclusion, this work demonstrated that knockdown of YAP and TAZ exerted a synergistic effect on alleviating SSc in mice. Thus, this work suggests that YAP/TAZ is a potential target for SSc treatment.

Investigation on the growth factor regulatory network of dermal fibroblasts in mouse full-thickness skin defect wounds based on single-cell RNA sequencing

Investigation on the growth factor regulatory network of dermal fibroblasts in mouse full-thickness skin defect wounds based on single-cell RNA sequencing

Mitoribosomal Deregulation Drives Senescence via TPP1-Mediated Telomere Deprotection.

While mitochondrial bioenergetic deregulation has long been implicated in cellular senescence, its mechanistic involvement remains unclear. By leveraging diverse mitochondria-related gene expression profiles derived from two different cellular senescence models of human diploid fibroblasts, we found that the expression of mitoribosomal proteins (MRPs) was generally decreased during the early-to-middle transition prior to the exhibition of noticeable SA-β-gal activity. Suppressed expression patterns of the identified senescence-associated MRP signatures (SA-MRPs) were validated in aged human cells and rat and mouse skin tissues and in aging mouse fibroblasts at single-cell resolution. TIN2- and POT1-interaction protein (TPP1) was concurrently suppressed, which induced senescence, accompanied by telomere DNA damage. Lastly, we show that SA-MRP deregulation could be a potential upstream regulator of TPP1 suppression. Our results indicate that mitoribosomal deregulation could represent an early event initiating mitochondrial dysfunction and serve as a primary driver of cellular senescence and an upstream regulator of shelterin-mediated telomere deprotection.

Landmark-based retrieval of inflamed skin vessels enabled by 3D correlative intravital light and volume electron microscopy

The nanometer spatial resolution of electron microscopy imaging remains an advantage over light microscopy, but the restricted field of view that can be inspected and the inability to visualize dynamic cellular events are definitely drawbacks of standard transmission electron microscopy (TEM). Several methods have been developed to overcome these limitations, mainly by correlating the light microscopical image to the electron microscope with correlative light and electron microscopy (CLEM) techniques. Since there is more than one method to obtain the region of interest (ROI), the workflow must be adjusted according to the research question and biological material addressed. Here, we describe in detail the development of a three-dimensional CLEM workflow for mouse skin tissue exposed to an inflammation stimulus and imaged by intravital microscopy (IVM) before fixation. Our aim is to relocate a distinct vessel in the electron microscope, addressing a complex biological question: how do cells interact with each other and the surrounding environment at the ultrastructural level? Retracing the area over several preparation steps did not involve any specific automated instruments but was entirely led by anatomical and artificially introduced landmarks, including blood vessel architecture and carbon-coated grids. Successful retrieval of the ROI by electron microscopy depended on particularly high precision during sample manipulation and extensive documentation. Further modification of the TEM sample preparation protocol for mouse skin tissue even rendered the specimen suitable for serial block-face scanning electron microscopy (SBF-SEM).

Abstract 2090: Humanized IL36R mice provide a preclinical tool for the evaluation of therapeutic drugs targeting IL36R

Abstract The IL36 family of cytokines (IL36a, IL36b, and IL36g) is part of the IL-1 superfamily and triggers proinflammatory signaling through the IL36 receptor complex. This heterodimer complex is formed by the IL36 Receptor (IL1RL2) and IL-1R co-receptor accessory protein (IL-1RAcP). IL36R is present on a diverse variety of cell types, including the surface of dendritic cells, CD4+ T cells, and epithelial cells in various tissues. IL36 signaling can exert widespread inflammation, and its activity is implicated in several inflammatory diseases affecting epithelial tissues, including inflammatory bowel disease, rheumatoid arthritis, and psoriasis. Thus, identification of novel therapeutics targeting this pathway are of significant clinical interest. To provide a preclinical platform for efficacy assessments of novel anti-human IL36R drugs, we generated a humanized hIL36R knock-in mouse model. In this model, a chimeric IL1RL2 coding sequence, which is composed of the human IL1RL2 extracellular region and the mouse Il1rl2 cytoplasmic region, was inserted after the 5’UTR of mouse Il1rl2 gene using CRISPR-Cas9-based gene editing technology. The mouse cytoplasmic region was maintained to ensure intact downstream signaling. Polymerase chain reaction assessment of mRNA isolated from the lung tissue of edited homozygous humanized IL36R mice confirmed the absence of mouse Il1rl2 transcripts. Finally, to confirm the expression of human IL36R protein, immunohistochemistry was performed on the small intestine and skin tissue of humanized mice subjected to a chemical induction of psoriasis. Psoriasis-like symptoms were achieved by application of imiquimod cream on the back skin of the mice for 5 consecutive days. As expected, IL36R protein expression was detected in both tissues isolated from the homozygous humanized mice. These results indicate the successful generation of humanized IL36R mice, and suggest that this model will be an effective tool for future in vivo efficacy evaluation of immunomodulatory drugs targeting human IL36R. Citation Format: Xiaofei Zhou, Jiahui Chang, Jenna Frame, Chong Li, Zhifang Bai, Yuelei Shen. Humanized IL36R mice provide a preclinical tool for the evaluation of therapeutic drugs targeting IL36R [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2090.

Role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice

Role and mechanism of Vγ4 T cells in impaired wound healing of rapamycin-induced full-thickness skin defects in mice

Endothelial Cell-Derived Extracellular Vesicles Target TLR4 via miRNA-326-3p to Regulate Skin Fibroblasts Senescence.

Backgrounds Skin aging could be regulated by the aberrant expression of microRNAs. In this manuscript, we explain that endothelial cell-derived extracellular vesicles could act as supporters to deliver exogenous miR-326-3p to accelerate skin fibroblasts senescence. Methods β-galactosidase senescence staining assay, Hoechst 33258 apoptosis staining assay, and Ki67 staining assay were used to evaluate the biological function of mouse skin fibroblasts. Real-time PCR was applied to assay miRNAs and mRNAs expressions. Western blot was used to detect TLR4 protein expression. The target gene of miRNA were identified using a double luciferase reporter assay. miR-326-3p mimic/inhibitor and siRNA-TLR4 can demonstrate a nonnegligible link between miR-326-3p-TLR4 and skin aging. Results In coculture experiment, senescence endothelial cells could promote the skin fibroblasts senescence and apoptosis via extracellular vesicles pathway. In contrast, miR-326-3p mimics accelerated senescence and apoptosis of skin fibroblasts, while miR-326-3p inhibitor could dramatically delay skin fibroblasts senescence and apoptosis. TLR4 was proved to be a miR-326-3p directly target gene via double luciferase assay. After skin fibroblasts transfected with siRNA-TLR4, cellular senescence and apoptosis were significantly increased. Furthermore, the skin tissues of aging mice were shown with overexpression of miR-326-3p and decrease of TLR4 gene and protein expression levels. Conclusions Endothelial cell-derived extracellular vesicles delivery of miR-326-3p was found to have a function in skin fibroblasts via target TLR4. Therefore, endothelial cell-derived extracellular vesicles in antiaging therapies might be a new treatment way for delaying skin aging.

SOD3 Suppresses the Expression of MMP-1 and Increases the Integrity of Extracellular Matrix in Fibroblasts.

The superoxide dismutase (SOD) family functions as a reactive oxygen species (ROS)-scavenging system by converting superoxide anions into hydrogen peroxide in the cytosol (SOD1), mitochondria (SOD2), and extracellular matrix (SOD3). In this study, we examined the potential roles of SOD family members in skin aging. We found that SOD3 expression levels were significantly more reduced in the skin tissues of old mice and humans than in young counterparts, but SOD1 and SOD2 expression levels remained unchanged with aging. Accordingly, we analyzed the effects of SOD3 on intracellular ROS levels and the integrity of the extracellular matrix in fibroblasts. The treatment of foreskin fibroblasts with recombinant SOD3 reduced the intracellular ROS levels and secretion of MMP-1 while increasing the secretion of type I collagen. The effects of SOD3 were greater in fibroblasts treated with the TNF-α. SOD3 treatment also decreased the mRNA levels and promoter activity of MMP-1 while increasing the mRNA levels and promoter activities of COL1A1 and COL1A2. SOD3 treatment reduced the phosphorylation of NF-κB, p38 MAPK, ERK, and JNK, which are essential for MMP-1 transactivation. In a three-dimensional culture of fibroblasts, SOD3 decreased the amount of type I collagen fragments produced by MMP-1 and increased the amount of nascent type I procollagen. These results demonstrate that SOD3 reduces intracellular ROS levels, suppresses MMP-1 expression, and induces type I collagen expression in fibroblasts. Therefore, SOD3 may play a role in delaying or preventing skin aging.

Synthesis and In-Vivo Evaluation of Benzoxazole Derivatives as Promising Anti-Psoriatic Drugs for Clinical Use.

2-(4-Chlorophenyl)-5-benzoxazoleacetic acid (CBA) and its ester, methyl-2-(4-chloro-phenyl)-5-benzoxazoleacetate (MCBA), were synthesized, and their structures were confirmed by 1HNMR, IR, and mass spectrophotometry. The anti-psoriatic activities of CBA and MCBA were tested using an imiquimod (IMQ)-induced psoriatic mouse model, in which mice were treated both topically (1% w/w) and orally (125 mg/kg) for 14 days. The erythema intensity, thickness, and desquamation of psoriasis were scored by calculating the psoriasis area severity index (PASI). The study also included the determination of histopathological alterations in the skin tissues of treated mice. Topical and oral administration of CBA and MCBA led to a reduction in erythema intensity, thickness, and desquamation, which was demonstrated by a significant decrease in the PASI value. In addition, skin tissues of mice treated with CBA and MCBA showed less evidence of psoriatic alterations, such as hyperkeratosis, parakeratosis, scale crust, edema, psoriasiform, and hyperplasia. After administration of either topical or oral dosing, the anti-psoriatic effects were found to be stronger in MCBA-treated than in CBA-treated mice. These effects were comparable to those produced by Clobetasol propionate, the reference drug. This drug discovery could be translated into a potential new drug for future clinical use in psoriasis treatment.

MDL-800, the SIRT6 Activator, Suppresses Inflammation via the NF-κB Pathway and Promotes Angiogenesis to Accelerate Cutaneous Wound Healing in Mice.

Sirtuin 6 (SIRT6) is an NAD+-dependent deacetylase belonging to the sirtuin family. It has been shown to participate in wound healing and some inflammation-related disorders. However, the effect of MDL-800, a highly efficient and selective SIRT6 activator, on wound healing and inflammation has not been reported. Therefore, this study investigated whether MDL-800 confers anti-inflammatory effects and promotes wound healing and uncovered the molecular mechanisms involved. This was achieved using mouse models of full-thickness wounds. Results showed that MDL-800 significantly downregulated inflammation by attenuating the release of inflammatory mediators and improved collagen deposition and neovascularization of wounds, thereby accelerating cutaneous wound healing. Furthermore, MDL-800 significantly downregulated expression levels of TNF-α and IL-6 in the dorsal skin tissue of mice via the NF-κB pathway. These results demonstrated that MDL-800 exerted anti-inflammatory and prohealing effects, indicating that the SIRT6/NF-κB/IκB signaling pathway may play an important role in wound healing.

Tea saponin extracted from seed pomace of Camellia oleifera Abel ameliorates DNCB-induced atopic dermatitis-like symptoms in BALB/c mice

Tea saponin (TS) has antibacterial and anti-inflammatory properties. However, the antipruritic and anti-inflammatory effects on atopic dermatitis (AD) are unknown. This study, therefore, evaluated the therapeutic effects of TS from seed pomace of C. oleifera on AD in 2,4-Dinitrochlorobenzene (DNCB)-caused BALB/c mice. The major compositions were separated and analyzed by ultrahigh-performance liquid chromatography Q-Exactive Orbitrap mass spectrometry. The antipruritic efficacy as well as the anti-inflammatory activity of TS were assessed using skin lesions, scratching tendency, and cytokine levels in DNCB-caused BALB/c mice. Twenty-six TS were preliminarily identified, and the dermatitis results revealed that TS could significantly reduce the degree of dermatitis and scratching in AD mice induced by DNCB. TS also normalized the skin barriers and inhibited the generation of inflammatory cytokines in the serum and skin tissue of mice. Overall, TS possesses antipruritic and anti-inflammatory properties, making it a potential natural resource for dermatitis treatment.

Development and Evaluation of a Film Forming System Containing Myricetin and Miconazole Nitrate for Preventing Candida albicans Catheter-Related Infection.

Background: Candida albicans catheter-related infection (CRI) is a great challenge in clinic now, mainly due to the difficulty in eradicating the biofilms. Purpose: In this study, the mechanism of the antibiofilm effect of myricetin (MY) on C. albicans was illustrated. A film forming system (FFS) containing MY and miconazole nitrate (MN) was developed, optimized, and evaluated. The anti-infection effect of MY+MN@FFS against C. albicans CRI was investigated in vivo. Study Design and Methods: To clarify the mechanism of the action of MY, the influence of MY on each key process of the formation of C. albicans biofilms was evaluated. To deliver MY and MN into the skin and form a drug reservoir on the surface of the skin, the FFS was used as a carrier and MY+MN@FFS was developed, optimized, and evaluated. After preliminary confirmation of drug safety, a percutaneously inserted C. albicans CRI mouse model was established to investigate the in vivo anti-infection effect of MY+MN@FFS by fluorescence microscopy and scanning electron microscopy on the outer surface of the catheters, hematoxylin/eosin staining, and periodic acid-Schiff staining of the mice skin tissues. Results: MY was found to inhibit the morphological transition of C. albicans and the secretion of exopolysaccharides, resulting in a reduction in biofilms. MY+MN@FFS exhibited excellent properties and no irritation to mice skin. In an in vivo anti-infection study, MY+MN@FFS exhibited an excellent preventive effect against percutaneously inserted C. albicans CRI. Conclusion: MY+MN@FFS might be a potential approach for effectively preventing percutaneously inserted C. albicans CRI in clinic.

Coassembly of Warm Temperature-Sensitive Transient Receptor Potential Vanilloid (TRPV) 3 and TRPV4 Channel Complexes with Distinct Functional Properties.

Heteromeric assembly of temperature-sensitive transient receptor potential (TRP) ion channels has been suggested to underlie the molecular basis of fine-tuning of temperature detection and chemical sensation. However, whether warm temperature-sensitive TRP vanilloid (TRPV) 3 and TRPV4 channels robustly expressed in the skin can form heteromeric assembly remains largely unknown. In this study, we show that TRPV3 and TRPV4 channels can coassemble into functional heterotetrameric channels with distinct properties. Confocal imaging reveals a colocalization and association of TRPV3 and TRPV4 proteins in cell membrane. Coimmunoprecipitation analysis demonstrates a strong protein-protein interaction between TRPV3 and TRPV4 subunits from heterogeneously expressed cells or mouse skin tissues through their C termini but not in TRPV3 knockout tissues. Coexpression of TRPV3 and TRPV4 channels yields a heterotetrameric channel complexes characterized by an intermediate single-channel conductance, distinct activation threshold, and pharmacology. Taken together, our findings demonstrate a heterotetrameric assembly of TRPV3 and TRPV4 channels, which may help explain the role of temperature-sensitive TRPV channels in fine-tuning of environmental detection and sensation in the skin. SIGNIFICANCE STATEMENT: The coassembly of transient receptor potential vanilloid (TRPV) 3 and TRPV4 channel complexes increases the functional diversity within the channel subfamily, which may serve as a molecular basis for fine-tuning of environmental detection and temperature sensation in mammals.

The medicinal mushroom Ganoderma lucidum attenuates UV-induced skin carcinogenesis and immunosuppression.

The medicinal mushroom Ganoderma lucidum is traditionally used for treating multiple diseases, including cancer. This study examined skin cancer preventive activity of a commercial product containing spore and fruiting body in 30:8 ratio (GLSF). Extracts of GLSF and spore component (GLS) were prepared using artificial gastrointestinal juice and examined on JB6 cells. GLSF and GLS dose-dependently inhibited epidermal growth factor-induced JB6 transformation at non-toxic concentrations. SKH-1 mice which were fed with diets containing GLSF (1.25%), GLS (0.99%) or the fruiting body (GLF) (0.26%) were exposed to chronic low-dose ultraviolet (UV) radiation to assess their effects on skin carcinogenesis. GLSF, but not GLS or GLF, reduced skin tumor incidence and multiplicity. In non-tumor skin tissues of mice, GLSF attenuated UV-induced epidermal thickening, expression of Ki-67, COX-2 and NF-κB, while in tumor tissues, GLSF increased expression of CD8 and Granzyme B. To examine the effects of GLSF on UV-induced immunosuppression, mice which were fed with GLSF were evaluated for the contact hypersensitivity (CHS) response to dinitrofluorobenzene (DNFB). GLSF significantly reversed UV-mediated suppression of DNFB-induced CHS by increasing CD8+ and decreasing CD4+ and FoxP3+ T-cells in mouse ears. Therefore, GLSF prevents skin cancer probably via attenuating UV-induced immunosuppression.