Down-modulation of Bis reduces the invasive ability of glioma cells induced by TPA, through NF-κB mediated activation of MMP-9.

Bcl-2 interacting cell death suppressor (Bis) has been shown to have anti-apoptotic and anti-stress functions. Recently, increased Bis expression was reported to correlate with glioma aggressiveness. Here, we investigated the effect of Bis knockdown on the acquisition of the invasive phenotype of A172 glioma cells, induced by 12-O-Tetradecanoylphorbol-3-acetate (TPA), using a Transwell assay. Bis knockdown resulted in a significant decrease in the migration and invasion of A172 cells. Furthermore, Bis knockdown notably decreased TPA-induced matrix metalloproteinase-9 (MMP-9) activity and mRNA expression, as measured by zymography and quantitative real time PCR, respectively. A luciferase reporter assay indicated that Bis suppression significantly down-regulated NF-κB-driven transcription. Finally, we demonstrated that the rapid phosphorylation and subsequent degradation of IκB-α induced by TPA was remarkably delayed by Bis knockdown. These results suggest that Bis regulates the invasive ability of glioma cells elicited by TPA, by modulating NF-κB activation, and subsequent induction of MMP-9 mRNA.

Expression of Bis in the mouse gastrointestinal system.

The Bcl-2 interacting death suppressor (Bis) protein is known to be involved in a variety of pathophysiological conditions. We recently generated bis-deficient mice, which exhibited early lethality with typical nutritional deprivation status. To further investigate the molecular basis for the malnutrition phenotype of bis deficient mice, we explored Bis expression in the digestive system of normal mice. Western blot analysis and quantitative real time reverse transcription polymerase chain reaction analysis indicated that Bis expression is highest in the esophagus, followed by the stomach, colon, jejunum and ileum. Immunohistochemical data indicated that Bis expression is restricted to the stratified squamous epitheliums in the esophagus and forestomach, and was not notable in the columnar epitheliums in the stomach, small intestine and colon. In addition, strong Bis immunoreactivity was detected in the striated muscles surrounding the esophagus and smooth muscles at a lesser intensity throughout the gastrointestinal (GI) tract. Ganglionated plexuses, located in submucous layers, as well as intermuscular layers, were specifically immunoreactive for Bis. Immunofluorescence studies revealed that Bis is co-localized in glial fibrillary acidic protein-expressing enteric glial cells. Immunostaining with neuron specific esterase antibodies indicate that Bis is also present in the cell bodies of ganglions in the enteric nervous system (ENS). Our findings indicate that Bis plays a role in regulating GI functions, such as motility and absorption, through modulating signal transmission between the ENS and smooth muscles or the intestinal epitheliums.

Anthocyanin Extracts from Black Soybean (Glycine max L.) Protect Human Glial Cells Against Oxygen-Glucose Deprivation by Promoting Autophagy.

Anthocyanins have received growing attention as dietary antioxidants for the prevention of oxidative damage. Astrocytes, which are specialized glial cells, exert numerous essential, complex functions in both healthy and diseased central nervous system (CNS) through a process known as reactive astrogilosis. Therefore, the maintenance of glial cell viability may be important because of its role as a key modulator of neuropathological events. The aim of this study was to investigate the effect of anthocyanin on the survival of glial cells exposed to oxidative stress. Our results demonstrated that anthocyanin extracts from black soybean increased survival of U87 glioma cells in a dose dependent manner upon oxygen-glucose deprivation (OGD), accompanied by decrease levels of reactive oxygen species (ROS). While treatment cells with anthocyanin extracts or OGD stress individually activated autophagy induction, the effect was significantly augmented by pretreatment cells with anthocyanin extracts prior to OGD. The contribution of autophagy induction to the protective effects of anthocyanin was verified by the observation that silencing the Atg5 expression, an essential regulator of autophagy induction, reversed the cytoprotective effect of anthocyanin extracts against OGD stress. Treatment of U87 cells with rapamycin, an autophagy inducer, increased cell survival upon OGD stress comparable to anthocyanin, indicating that autophagy functions as a survival mechanism against oxidative stress-induced cytotoxicity in glial cells. Our results, therefore, provide a rationale for the use of anthocyanin as a preventive agent for brain dysfunction caused by oxidative damage, such as a stroke.

Enhanced chondrogenic responses of human articular chondrocytes onto silk fibroin/wool keratose scaffolds treated with microwave-induced argon plasma.

Silk fibroin (SF) is a natural, degradable, fibrous protein that is biocompatible, is easily processed, and possesses unique mechanical properties. Another natural material, wool keratose (WK), is a soluble derivative of wool keratin, containing amino acid sequences that induce cell adhesion. Here, we blended SF and WK to improve the poor electrospinability of WK and increase the adhesiveness of SF. We hypothesized that microwave-induced argon plasma treatment would improve chondrogenic cell growth and cartilage-specific extracellular matrix formation on a three-dimensional SF/WK scaffold. After argon plasma treatment, static water contact angle measurement revealed increased hydrophilicity of the SF/WK scaffold, and scanning electron microscopy showed that treated SF/WK scaffolds had deeper and more cylindrical pores than nontreated scaffolds. Attachment and proliferation of neonatal human knee articular chondrocytes on treated SF/WK scaffolds increased significantly, followed by increased glycosaminoglycan synthesis. Our results suggest that microwave-induced, plasma-treated SF/WK scaffolds have potential in cartilage tissue engineering.