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We conducted large‐scale screening test on drugs that were already approved for other diseases to find pigmentation‐modulating agents. Among drugs with potential for pigmentation control, we selected sorafenib and further investigated the effect on pigmentation using HM3KO melanoma cells. As a result of treating melanoma cells with sorafenib, pigmentation was promoted in terms of melanin content and tyrosinase activity. Sorafenib increased mRNA and protein levels of pigmentation‐related genes such as MITF, tyrosinase and TRP1. To uncover the action mechanism, we investigated the effect of sorafenib on the intracellular signalling pathways. Sorafenib reduced phosphorylation of AKT and ERK, suggesting that sorafenib induces pigmentation through inhibition of the AKT and ERK pathways. In addition, sorafenib significantly increased the level of active β‐catenin, together with activation of β‐catenin signalling. Mechanistic study revealed that sorafenib decreased phosphorylation of serine 9 (S9) of GSK3β, while it increased phosphorylation of tyrosine 216 (Y216) of GSK3β. These results suggest that sorafenib activates the β‐catenin signalling through the regulation of GSK3β phosphorylation, thereby affecting the pigmentation process. [ABSTRACT FROM AUTHOR]

Whether osteoarthritis (OA) is associated with alterations in the epigenetic status of anabolic factors is largely unknown. To answer the question, we investigated the DNA methylation and histone modification of SOX-9 gene promoter, a typical anabolic gene, in the articular cartilage from nine patients with femoral neck fractures without OA and from nine hip OA patients. Methylation-specific PCR (MSP) and bisulfite sequencing analysis (BSQ) showed that the methylation of SOX-9 promoter was increased in OA cartilage compared to normal cartilage. The decreased SOX-9 gene and protein expression in OA chondrocytes was reversed by the treatment of 5-azacytidine (5-AzaC), the demethylating agent. Methylation of SOX-9 proximal promoters reduced the binding affinity of transcription factors CCAAT-binding factor/nuclear factor-Y and cyclic adenosine monophosphate (cAMP) response element-binding. There was a significant increase in H3K9 and H3K27 trimethylation and a significant decrease in the acetylation of H3K9, 15, 18, 23, and 27 at SOX-9 promoters in OA chondrocytes. These findings suggest that hip OA is associated with a change in the epigenetic status of SOX-9 promoter, including increased DNA methylation and altered histone modification. © 2013 American Society for Bone and Mineral Research. [ABSTRACT FROM AUTHOR]

Abstract: Receptor-interacting protein 3 (RIP3) has been implicated in ischemic necrosis of retinal cells. An in silico analysis followed by experimental validation identified death associated protein (Daxx) as a novel substrate of RIP3. In vitro binding studies revealed that RIP3 binds to the serine/proline/threonine-rich domain (amino acid 625–740) of Daxx. Upon ischemic insult, RIP3 phosphorylated Daxx at Ser-668 in the retinal ganglion cells, triggering nuclear export of Daxx. Depletion of RIP3 significantly inhibited nuclear export of Daxx and attenuated cell death to a great extent. Collectively, the findings of this study demonstrate that phosphorylation of Daxx by RIP3 comprises an important part of ischemic necrosis in rat retinal ganglion cells. Structured summary of protein interactions: Daxx binds to Rip3 by pull down(View Interaction: 1, 2) Rip3 and Daxx colocalize by fluorescence microscopy(View interaction) Rip3 physically interacts with Daxx by anti bait coimmunoprecipitation (View interaction) Daxx binds to Rip1 bypull down(View interaction) [Copyright &y& Elsevier]

The cytotoxic effect of 3- O-acetyloleanolic acid, an oleanolic acid derivative isolated from the seeds of Vigna sinensis K., was investigated in human colon carcinoma HCT-116 cells. 3- O-acetyloleanolic acid dose-dependently inhibited the viability of HCT-116 cells. Apoptosis was characterized by detection of cell surface annexin V and sub-G1 apoptotic cell populations. The number of immunostained cells with annexin V-FITC was increased after treatment with 3- O-acetyloleanolic acid. The sub-G1 cell population was also increased. Expression of TRAIL-mediated apoptosis signaling-related death receptor DR5 was increased in 3- O-acetyloleanolic acid-treated HCT-116 cells. Activation of caspase-8 and caspase-3, critical mediators of extrinsic apoptosis signaling, was also increased by 3- O-acetyloleanolic acid. The results indicate that 3- O-acetyloleanolic acid induces apoptosis in HCT-116 cells mediated by an extrinsic apoptosis signaling cascade via up-regulation of DR5. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]