Uridine phosphorylase-1 promotes cell viability and cell-cycle progression in human epidermal keratinocytes via the glycolytic pathway.

Glycolysis is vital for the excessive proliferation of keratinocytes in psoriasis, and uridine phosphorylase-1 (UPP1) functions as an enhancer of cancer cell proliferation. However, little is known about whether UPP1 promotes keratinocyte proliferation and accelerates psoriasis development. This study revealed that UPP1 facilitates cell viability and cell-cycle progression in human epidermal keratinocytes (HEKs) by modulating the glycolytic pathway. Bioinformatics analysis of UPP1 gene expression and its correlation with the Reactome revealed that UPP1 mRNA expression, cell-cycle progression, the interleukin-6 (IL-6)/Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway and glycolysis were positively associated with psoriasis. Cell proliferation, the cell cycle and glycolysis were evaluated after UPP1 was silenced or overexpressed. The results showed that UPP1 overexpression increased cell proliferation, cell-cycle progression and glycolysis, which was contrary to the effects of UPP1 silencing. However, the STAT3 inhibitor diminished UPP1 expression because STAT3 can bind to the UPP1 promoter. In conclusion, UPP1 was significantly activated by the IL-6/STAT3 pathway and could modulate glycolysis to regulate cell proliferation and cell-cycle progression in keratinocytes during the development of psoriasis.

Huang Lian Jie Du Decoction enhances the anti-tumor efficacy of immune checkpoint inhibitors by activating TLR7/8 signalling in melanoma.

BACKGROUND: The clinical application of immune checkpoint inhibitors (ICIs) is limited by their drug resistance, necessitating the development of ICI sensitizers to improve cancer immunotherapy outcomes. Huang Lian Jie Du Decoction (HLJD, Oren-gedoku-to in Japanese, Hwangryunhaedok-tang in Korean), a famous traditional Chinese medicinal prescription, has exhibited potential in the field of cancer treatment. This study aims to investigate the impact of HLJD on the efficacy of ICIs in melanoma and elucidate the underlying mechanisms. METHODS: The potential synergistic effects of HLJD and ICIs were investigated on the tumor-bearing mice model of B16F10 melanoma, and the tumor infiltration of immune cells was tested by flow cytometry. The differential gene expression in tumors between HLJD and ICIs group and ICIs alone group were analyzed by RNA-seq. The effects of HLJD on oxidative stress, TLR7/8, and type I interferons (IFN-Is) signaling were further validated by immunofluorescence, PCR array, and immunochemistry in tumor tissue. RESULTS: HLJD enhanced the anti-tumor effect of ICIs, significantly inhibited tumor growth, and prolonged the survival duration in melanoma. HLJD increased the tumor infiltration of anti-tumor immune cells, especially DCs, CD4+ T cells and CD8+T cells. Mechanically, HLJD activated the oxidative stress and TLR7/8 signaling pathway and IFN-Is-related genes in tumors. CONCLUSIONS: HLJD enhanced the therapeutic benefits of ICIs in melanoma, through increasing reactive oxygen species (ROS), promoting the TLR7/8 pathway, and activating IFN-Is signaling, which in turn activated DCs and T cells.

Lung-protective effect of Punicalagin on LPS-induced acute lung injury in mice.

BACKGROUND: Punicalagin (Pun) is one of the main bioactive compounds in pomegranate peel, it possesses many properties, including antioxidant, anti-inflammation and immunosuppressive activities. The study was aimed to investigate the protective effect and mechanisms of Pun on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. METHODS AND RESULTS: Forty-eight BALB/c male mice were used to establish ALI by intratracheal-instilled 2.4 mg/kg LPS, the mice were randomly divided into model and Pun (10, 20, 40 mg/kg) groups. The other 12 mice were intratracheal-instilled same volume of water as control. After 2 h of receiving LPS, mice were administered drug through intraperitoneal injection. Lung index, histopathological changes, white blood cells and biomarkers in bronchoalveolar lavage fluid (BALF) were analyzed. The protein expression of total and phosphor p65, IκBα, ERK1/2, JNK and p38 in lung tissue was detected. The result showed that Pun could reduce the lung index and wet/dry weight (W/D) ratio, improve lung histopathological injury. In addition, Pun decreased the inflammation cells and regulated the biomarkers in BALF. Furthermore, Pun dose-dependently reduced the phosphor protein levels of p65, IκBα, ERK1/2, JNK and p38 in lung tissue, which exhibited that the effect of Pun related to mitogen-activated protein kinases (MAPKs) pathway. More importantly, there was no toxicity was observed in the acute toxicity study of Pun. CONCLUSION: Pun improves LPS-induced ALI mainly through its anti-inflammatory properties, which is associated with nuclear factor-κB (NF-κB) and MAPKs signaling pathways. The study implied that Pun maybe a potent agent against ALI in future clinic.

DUOX2 participates in skin aging induced by UVB in HSF2 cells by activating NF-κB signaling.

Skin and in particular photoaging or premature aging, are caused by a variety of factors, including hormone imbalance and exposure to ultraviolet radiation. The aim of the present study was to explore the roles of Dual oxidase 2 (DUOX2) and related NF-κB signals in skin photoaging. Cell models of photoaging were constructed by irradiating human skin fibroblast lines (HSF2) with ultraviolet B (UVB) of different doses (0, 15, 30 and 60 mj/cm2). The cell counting kit-8 (CCK8) was used to determine cell proliferation. Flow cytometry was used to determine the production of reactive oxygen species (ROS). A biochemical method was to determine the content of hydrogen peroxide, and the quantitative PCR (qPCR) was used to determine the expression of matrix metalloproteinase 2 (MMP2), matrix metalloproteinase 9 (MMP9), Col-Ⅰ and α-SMA in the cells. Enzyme-linked immunosorbent assay (ELISA) was used to determine the expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Western blot analysis was performed to determine the expression of DUOX2, p65 and p-p65. The results showed that,UVB irradiation dose- and time-dependently inhibited the proliferation of HSF2 cells. Cellular inflammatory response, ROS production and hydrogen peroxide increase was promoted. Col-Ⅰ and α-SMA were downregulated, MMP2 and MMP9 were upregulated, and the phosphorylation of NF-κB p65 was promoted. The above indicators were all reversed by interference with DUOX2. Overexpression of DUOX2 has an effect that is similar to UVB irradiation, but the effects can be significantly weakened by NF-κB inhibitor, NAC. Upregulation of DUOX2 expression plays a crucial role in UVB-induced aging of HSF2 cells. The specific mechanism is related to the promotion of ROS production and cellular inflammatory response and activation of NF-κB signals.

Nationwide Survey and Identification of Potential Stress Factor in Sensitive Skin of Chinese Women.

PURPOSE: Sensitive skin is characterized by uncomfortable sensations in response to a number of factors. We performed a large-scale study to investigate the prevalence of sensitive skin at all ages and the impacts of related factors across China. METHODS: A nationwide sampling of the Chinese population aged over 18 was conducted. Subjects were categorized into sensitive and non-sensitive groups, and critical differences between these two groups were investigated. RESULTS: In total, 22,085 questionnaires were collected from Chinese women with sensitive skin. The prevalence of sensitive skin is 49.6% and is associated with age, skin type, geographic area of subjects, and other factors. Heavy life stress and the application of several cosmetic products also affect the prevalence of sensitive skin. CONCLUSION: Having a combination or oily skin type, living in the municipalities, being under heavy stress, and applying several cosmetic products will increase skin stress and contribute to the occurrence of sensitive skin.

Curcumin against imiquimod-induced psoriasis of mice through IL-6/STAT3 signaling pathway.

BACKGROUND: To explore the possible mechanism of Curcumin (Cur) for protecting imiquimod-induced psoriasis in mice. METHODS AND RESULTS: Sixty BALB/c mice were removal the back hair about 2 cm × 3 cm and divided into five groups. The control group was used Vaseline, the model and the drug group used 5% imiquimod in the back skin for 7 days, once time a day (62.5 mg/day/mice). At the same time, control and model mice were intragastric administration of normal saline, while the drug group were orally administrated with 50, 100 and 200 mg/kg Cur, respectively. The morphology, histopathological changes were observed. The serum levels of tumor necrosis factor-alpha (TNF-α) and Interleukin-6 (IL-6) were analyzed by ELISA. The protein expression levels of phosphorylation STAT 3 and its down-stream protein expression in lesion skin were detected by western blot. The protein expression of TNF-α and IL-6 in lesion skin were analyzed by immunohistochemistry. The result showed that Cur could improve the lesion skin pathological, decrease the levels of TNF-α and IL-6 in serum and in lesion skin of psoriasis mice. In addition, Cur also reduced the protein levels of phosphorylation STAT 3 and its down-stream protein levels of Cyclin D1, Bcl-2 and Pim 1 in lesion skin of psoriasis mice. CONCLUSION: Cur could effectivly improve the pathological characteristics of psoriasis mice, which may be through the regulation of IL-6/STAT3 signaling pathway.

Inhibition of SOX4 induces melanoma cell apoptosis via downregulation of NF-κB p65 signaling.

SOX4 (SRY Box 4) has attracted attention due to its important effects on cell growth, proliferation and apoptosis, among other cellular processes. However, the role of SOX4 in melanoma cell apoptosis remains unclear. In the present study, we investigated whether inhibition of SOX4 induces melanoma cell apoptosis, and explored the possible mechanism involving the NF-κB signaling pathway. SOX4 was knocked down using a lentivirus in melanoma A2058 and SK-MEL-5 cell lines. Cell proliferation was measured by MTT assay. Apoptosis was determined by flow cytometry. Western blotting was performed to detect the protein levels of SOX4, p65 and apoptosis-related proteins, such as PARP, Bcl-2, Bax and survivin. Quantitative real-time PCR (qRT-PCR) was used to examine the mRNA levels of SOX4 and p65. To determine whether SOX4 is able to bind to the promoter of p65, a CHIP-PCR assay was performed. Our data demonstrated that SOX4 knockdown significantly induced apoptosis in melanoma cells, which was accompanied by increases in cleaved PARP and Bax, and decreases in Bcl-2 and survivin. The expression of p65 was also decreased in SOX4-knockdown melanoma cells. The CHIP-PCR assay indicated that SOX4 was able to bind to the promoter region of p65. We also observed that apoptosis in SOX4-knockdown and p65-overexpressing A2058 cells was much lower than that in SOX4-knockdown alone cells. This revealed that the overexpression of p65 partially reversed SOX4 downregulation-induced apoptosis. In conclusion, our results demonstrated that inhibition of SOX4 markedly induced melanoma cell apoptosis via downregulation of the NF-κB signaling pathway, which thus may be a novel approach for the treatment of melanoma.

SOX4 promotes melanoma cell migration and invasion though the activation of the NF-κB signaling pathway.

SOX4 has been reported to be abnormally expressed in many types of cancer, including melanoma. However, its role in cell proliferation and metastasis remains controversial. In this study, SOX4 was downregulated or overexpressed in A375, A2058 and A875 melanoma cells by siRNA or lentivirus transfection, respectively. Cell metastasis was observed by Transwell assay. In an aim to elucidate the underlying mechanisms, we determined the expression of nuclear factor-κB (NF-κB) by real-time PCR assay and western blot analysis. Our data indicated that SOX4 knockdown inhibited melanoma cell migration and invasion. In the melanoma cells in which SOX4 was downregulated, the expression levels of NF-κB/p65, matrix metalloproteinase (MMP)2 and MMP9 were suppressed at both the mRNA and protein levels. Conversely, the overexpression of SOX4 promoted melanoma cell migration and invasion. In the melanoma cells in which SOX4 was overexpressed, the expression levels of NF-κB/p65, MMP2 and MMP9 were increased at both the mRNA and protein level. On the whole, our findings indicate that SOX4 promotes melanoma cell migration and invasion through the activation of the NF-κB/p65 signaling pathway. Thus, SOX4 may prove to be a potential therapeutic target for the treatment of melanoma.

Paeoniflorin attenuates ultraviolet B-induced apoptosis in human keratinocytes by inhibiting the ROS-p38-p53 pathway.

Ultraviolet (UV) light is one of the most harmful environmental factors that contribute to skin damage. Exposure to UV induces extensive generation of reactive oxygen species (ROS), and results in photoaging and skin cancer development. One approach to protecting human skin against UV radiation is the use of antioxidants. In recent years, naturally occurring herbal compounds have gained considerable attention as protective agents for UV exposure. Paeoniflorin (PF) is a novel natural antioxidant, which is isolated from peony root (Radix Paeoniae Alba). The present study evaluated the protective effects of PF on UV­induced skin damage in vitro, and demonstrated that the effects were mediated via the ROS­p38­p53 pathway. The results of the present study demonstrated that treatment with PF (25, 50, and 100 µM) significantly increased the percentage of viable keratinocytes after UV­B exposure. In addition, cell death analysis indicated that PF treatment markedly reduced UV­B­radiation­induced apoptosis in keratinocytes, which was accompanied by increased procaspase 3 expression and decreased cleaved caspase 3 expression. Treatment with PF markedly reduced the production of ROS, and inhibited the activation of p38 and p53 in human keratinocytes, thus suggesting that the ROS­p38­p53 pathway has a role in UV­B­induced skin damage. In conclusion, the present study reported that PF was able to attenuate UV­B­induced cell damage in human keratinocytes. Notably, these effects were shown to be mediated, at least in part, via inhibition of the ROS-p38-p53 pathway.

Icariside II induces apoptosis via inhibition of the EGFR pathways in A431 human epidermoid carcinoma cells.

Improvements in skin cancer treatment are likely to derive from novel agents targeting the molecular pathways that promote tumor cell growth and survival. Icariside II (IS) is a metabolite of icariin, which is derived from Herba Epimedii. The aim of the present study was to evaluate the antitumor effects of IS and to determine the mechanism of apoptosis in A431 human epidermoid carcinoma cells. A431 cells were treated with IS (0­100 µM) for 24 or 48 h and cell viability was detected using the WST­8 assay. Apoptosis was measured by the Annexin­V/propidium iodide (PI) flow cytometric assay. Western blot analysis was used to measure the expression of cleaved caspase­9, cleaved poly ADP ribose polymerase (PARP), phosphorylated signal transducer and activator of transcription 3 (P­STAT3), phosphorylated extracellular signal-regulated kinase (P­ERK), and P­AKT. A431 cells were also pretreated with IS (0­100 µM) 2 h prior to treatment with epidermal growth factor (EGF; 100 ng/ml) for 10 min. Phosphorylated EGF receptor (P­EGFR), P­STAT3, P­ERK and P­AKT were detected by western blot analysis. The results demonstrated that IS inhibited the cell viability of the A431 cells in a dose­dependent manner. Pretreatment with LY294002 [a phosphatidylinositol 3-kinase (PI3K) inhibitor], EGF (an EGFR agonist) and AG1478 (an EGFR inhibitor) partially reversed IS­induced decreases in cell viability. Treatment with 50 µm IS resulted in an increased number of apoptotic cells mirrored by increases in cleaved caspase­9 and cleaved PARP. In addition, treatment with 50 µM IS significantly inhibited the activation of the Janus kinase (JAK)­STAT3 and mitogen­activated protein kinase (MAPK)­ERK pathways, but promoted the activation of the PI3K­AKT pathway. Furthermore, IS effectively inhibited the EGF-induced activation of the EGFR pathways. In conclusion, IS inhibited the cell viability of the A431 cells through the regulation of apoptosis. These effects were mediated, at least in part, by inhibiting the activation of the EGFR pathways.

Narrow-band UVB radiation promotes dendrite formation by activating Rac1 in B16 melanoma cells.

Melanocytes are found scattered throughout the basal layer of the epidermis. Following hormone or ultraviolet (UV) light stimulation, the melanin pigments contained in melanocytes are transferred through the dendrites to the surrounding keratinocytes to protect against UV light damage or carcinogenesis. This has been considered as a morphological indicator of melanocytes and melanoma cells. Small GTPases of the Rho family have been implicated in the regulation of actin reorganization underlying dendrite formation in melanocytes and melanoma cells. It has been proven that ultraviolet light plays a pivotal role in melanocyte dendrite formation; however, the molecular mechanism underlying this process has not been fully elucidated. The effect of small GTPases, such as Rac1 and RhoA, on the morphology of B16 melanoma cells treated with narrow-band UVB radiation was investigated. The morphological changes were observed under a phase contrast microscope and the F-actin microfilament of the cytoskeleton was observed under a laser scanning confocal microscope. The pull-down assay was performed to detect the activity of the small GTPases Rac1 and RhoA. The morphological changes were evident, with globular cell bodies and increased numbers of tree branch-like dendrites. The cytoskeletal F-actin appeared disassembled following narrow-band UVB irradiation of B16 melanoma cells. Treatment of B16 melanoma cells with narrow-band UVB radiation resulted in the activation of Rac1 in a time-dependent manner. In conclusion, the present study may provide a novel method through which narrow-band UVB radiation may be used to promote dendrite formation by activating the Rac1 signaling pathway, resulting in F-actin rearrangement in B16 melanoma cells.

Cultured human melanocytes express functional toll-like receptors 2-4, 7 and 9.

BACKGROUND: Toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs), which have been evolutionarily conserved in microbes. Human melanocytes are not simply pigment-producing cells but also have the phagocytic capacity and can produce pro-inflammatory mediators. However, the mechanisms of recognition of microbes by melanocytes have not yet been fully established. OBJECTIVE: We investigated the TLRs 1-10 expression profile in human epidermal melanocytes and assessed their functions after triggering by their specific ligands. METHODS: TLRs mRNA expression was determined by RT-PCR, and the TLR protein expression was measured by flow cytometry and immunofluorescence assays. After stimulation with various TLR ligands, the production of inflammatory cytokine IL-8 and IL-6 was measured by ELISA and the mRNA for chemokine CCL2, CCL3 and CCL5 was analyzed by real-time PCR. Phosphorylation of IkappaBalpha in TLR ligands-triggered melanocytes was determined by Western blot and the nucleus translocation of NF-kappaBp65 was analyzed by immunofluorescence. RESULTS: Human melanocytes constitutively expressed TLRs 1-4, 6, 7 and 9 mRNA. Ample amounts of TLRs 2-4, 7 and 9 were confirmed at protein level. Stimulation of melanocytes with TLRs ligands resulted in the release of cytokines (IL-8 and IL-6) and the mRNA accumulation of chemokines (CCL2, CCL3 and CCL5). Triggering of TLRs in melanocytes resulted in the up-regulation of phosphorylated IkappaBalpha and in the nucleus translocation of NF-kappaBp65. CONCLUSION: Present study indicates human melanocytes express a panel of functional TLRs. The ligation of TLRs can turn these cells into active players of the skin innate immunity.