Selaginellin Inhibits Melanogenesis via the MAPK Signaling Pathway.

Hyperpigmented skin diseases such as melasma, freckles, and melanosis usually mar the appearance of patients. Traditional herbal medicines are highly accepted in inhibiting skin pigmentation, with advantages of high efficiency, low cost, and low side effects. Selaginellin (SEL), one of the active compounds of selaginella, has been proved to be exhibit antineoplastic, antioxidant, antisenescence, and antiapoptosis activities. In this study, we found that SEL can inhibit melanogenesis in vitro and in vivo. A mechanism study found that SEL inhibits melanogenesis through inhibiting the mitogen-activated protein kinase (MAPK) signaling pathway, then down-regulating the expression of microphthalmia-associated transcription factor (MITF) and downstream genes tyrosinase (TYR) and tyrosinase-related protein 2 (TYRP2). UVB-activated paracrine function of fibroblasts and keratinocytes promotes melanogenesis of melanocytes. Interestingly, SEL antagonizes UVB-activated paracrine function of fibroblasts and keratinocytes. These findings indicate that SEL can be a potential whitening compound to inhibit melanogenesis.

RIPK4 promotes bladder urothelial carcinoma cell aggressiveness by upregulating VEGF-A through the NF-κB pathway.

BACKGROUND: Constitutively activated nuclear factor kappa B (NF-κB) signalling plays vital roles in bladder urothelial carcinoma (BC) progression. We investigate the effect of receptor-interacting protein kinase 4 (RIPK4) on NF-κB activation and BC progression. METHODS: The expression of RIPK4 was examined in 25 cryopreserved paired bladder samples and 112 paraffin BC specimens. In vivo and in vitro assays were performed to validate effect of RIPK4 on NF-κB pathway-mediated BC progression. RESULTS: High expression of RIPK4 was observed in BC tissues and was an independent predictor for poor overall survival. Up or downregulating the expression of RIPK4 enhanced or inhibited, respectively, the migration and invasion of BC cells in vitro and in vivo. Mechanistically, RIPK4 promoted K63-linked polyubiquitination of tumour necrosis factor receptor-associated factor 2 (TRAF2), receptor-interacting protein (RIP) and NF-κB essential modulator (NEMO). RIPK4 also promoted nuclear localisation of NF-κB-p65, and maintained activation of NF-κB substantially, leading to upregulation of VEGF-A, ultimately promoting BC cell aggressiveness. CONCLUSIONS: Our data highlighted the molecular aetiology and clinical significance of RIPK4 in BC: upregulation of RIPK4 contributes to NF-κB activation, and upregulates VEGF-A, and BC progression. Targeting RIPK4 might represent a new therapeutic strategy to improve survival for patients with BC.

[Neuroprotective mechanism of hydrogen sulfide after cerebral ischemia-reperfusion in rats].

OBJECTIVE: To explore the neuroprotective mechanism of exogenous hydrogen sulfide after cerebral ischemia-reperfusion (I/R) in rats. METHODS: A total of 240 male Sprague-Dawley rats were randomly divided into 4 groups of sham-operation group (I), I/R model group (II), low-dose sodium hydrosulfide (NaHS) group (III) and high-dose NaHS group (IV) (n = 60 each). Reversible middle cerebral artery occlusion (MCAO) model was established by intraluminal suture. However, the rats of group I were operated without a blockage of middle cerebral artery. The occlusions in other groups were removed after 2 h. And at 20 min pre-removal, normal saline, 50 µmol/kg NaHS, and 100 µmol/kg NaHS were injected into the abdomens of rats in groups II, III and IV respectively. At 6 h, 24 h, 48 h and 7 d post-reperfusion, behavioral test was performed to evaluate the neurological deficiency. And triphenyltetrazolium chloride (TTC) staining was used to observe the volume of cerebral infarction. In addition, the protein expressions of tumor necrosis factor-alpha (TNF-α) and heat shock protein 20 (HSP20) in ischemic cortex were measured by immunohistochemistry and Western blot. RESULTS: Compared with I/R group, the neurological deficiency scores and volume of cerebral infarction of groups III and IV significantly decreased. Furthermore, the protein expression of HSP20 was markedly up-regulated in the groups III and IV while there was a marked down-regulation of TNF-α after reperfusion. CONCLUSION: NaHS may exert anti-necrotic and anti-inflammatory function by inducing the expression of HSP20, inhibiting the expression of TNF-α and reducing the size of cerebral infarction so as to protect neurons after I/R injury.

Article Effect and Mechanism of Ganoderma lucidum Polysaccharides on Human Fibroblasts and Skin Wound Healing in Mice.

OBJECTIVE: To investigate the effects of Ganoderma lucidum polysaccharides (GL-PS) on human fibroblasts and skin wound healing in Kunming male mice and to explore the putative molecular mechanism. METHODS: Primary human skin fibroblasts were cultured. The viability of fibroblasts treated with 0, 10, 20, 40, 80, and 160 µg/mL of GL-PS, respectively were detected by 3-4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2-Htetrazolium bromide (MTT). The migration ability of fibroblasts treated with 0, 10, 20, and 40 µg/mL of GL-PS were measured by transwell assay. The secretion of the C-terminal peptide of procollagen type I (CICP) and transforming growth factor-ß1 (TGF-ß1) in the cell supernatant was tested by enzyme-linked immunosorbent assay. The expression of ß-catenin was detected by Western blot. Furthermore, the Kunming mouse model with full-layer skin resection trauma was established, and was treated with 10, 20, and 40 mg/mL of GL-PS, respectively as external use. The size of the wound was measured daily, complete healing time in each group was recorded and the percentage of wound contraction was calculated. RESULTS: Compared with the control group, 10, 20, and 40 µg/mL of GL-PS significantly increased the viability of fibroblasts, promoted the migration ability of fibroblasts, and up-regulated the expressions of CICP and TGF-ß1 in fibroblasts (Plt;0.05 or Plt;0.01). The expression of ß-catenin in fibroblasts treated with 20 and 40 µg/mL of GL-PS was significantly higher than that of the control group (Plt;0.01). Furthermore, after external use of 10, 20, and 40 mg/mL of GL-PS, the rates of wound healing in mice were significantly higher and the wound healing time was significantly less than the control group (Plt;0.05 or Plt;0.01). CONCLUSION: A certain concentration of GL-PS may promote wound healing via activation of the Wnt/ß-catenin signaling pathway and up-regulation of TGF-ß1, which might serve as a promising source of skin wound healing.

Increased 5-hydroxymethylcytosine and Ten-eleven Translocation Protein Expression in Ultraviolet B-irradiated HaCaT Cells.

BACKGROUND: DNA hydroxymethylation refers to a chemical modification process in which 5-methylcytosine (5mC) is catalyzed to 5- hydroxymethylcytosine (5hmC) by ten-eleven translocation (TET) family proteins. Recent studies have revealed that aberrant TETs expression or 5hmC level may play important roles in the occurrence and development of various pathological and physiological processes including cancer and aging. This study aimed to explore the relation between aberrant DNA hydroxymethylation with skin photoaging and to investigate the levels of TETs, 5mC, and 5hmC expression 24 h after 40 mJ/cm2 and 80 mJ/cm2 doses of ultraviolet B (UVB) irradiation to HaCaT cells. METHODS: To explore whether aberrant DNA hydroxymethylation is also related to skin photoaging, 40 mJ/cm2 and 80 mJ/cm2 doses of UVB were chosen to treat keratinocytes (HaCaT cells). After 24 h of UVB irradiation, 5mC and 5hmC levels were determined by immunohistochemistry (IHC) and immunofluorescence (IF), and at the same time, the expression levels of matrix metalloproteinase 1 (MMP-1) and TETs were assessed by reverse transcription-polymerase chain reaction or Western blot analysis. RESULTS: After 40 mJ/cm2 and 80 mJ/cm2 doses of UVB exposure, both IHC and IF results showed that 5hmC levels increased significantly, while the 5mC levels did not exhibit significant changes in HaCaT cells, compared with HaCat cells without UVB exposure. Moreover, compared with HaCat cells without UVB exposure, the levels of TET1, TET2, and TET3 mRNA and protein expression were significantly upregulated (mRNA: P = 0.0022 and 0.0043 for TET1; all P < 0.0001 for TET2; all P = 0.0006 for TET3; protein: P = 0.0012 and 0.0006 for TET1; all P = 0.0022 for TET2; and all P = 0.0002 for TET3), and the levels of MMP-1 mRNA expression increased dose dependently in 40 mJ/cm2 and 80 mJ/cm2 UVB-irradiated groups. CONCLUSION: UVB radiation could cause increased 5hmC and TET expression, which might become a novel biomarker in UVB-related skin aging.