Mesoporous NiO-samaria doped ceria for low-temperature solid oxide fuel cells.

In order to prepare anode material for low-temperature solid oxide fuel cells (SOFCs), the mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyltrimethyl-ammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB). In addition, Ni-SDC anode-supported SOFC single cells with YSZ electrolyte and LSM cathode were fabricated and the performance of single cells was evaluated at 600 °C. The microstructure of NiO-SDC was characterized by XRD, EDX, SEM, and BET, and the results showed that the mesoporous NiO-SDC with 10 nm pores could be obtained. It was found that the surface area and the electrical performance were strongly influenced by the Ni content in Ni-SDC cermets. After calcined at 600 °C, the surface area of NiO-SDC was between 90-117 m2/g at 35-45 Ni wt%, which was sufficiently high for providing large TPB in SOFC anode. The optimum Ni content for cell performance was around 45 wt% and the corresponding MPD was 0.36 W/cm2. Indeed, the mesoporous NiO-SDC cermet may be of interest for use as an anode for low-temperature SOFCs.

Effects of maternal nonylphenol exposure on the proliferation of glial cells in the brain of male offspring mice.

Glial cells play a significant role in maintaining brain homeostasis and normal brain development, and their functions can be impaired by exposure to endocrine disruptors. 4-n-Nonylphenol (NP), a representative endocrine disruptor, is widely used in personal care products and industrial materials. NP accumulates in various organs, including the brain, of living organisms and adversely influences brain health. However, studies on the effects of NP on glial cells are limited. This study aims to investigate the effects of NP on glial cells using primary mixed glial cells and offspring mice exposed to NP during gestation and lactation. In vitro experiments revealed that NP exposure stimulated the astrocytes and microglia proliferation but not oligodendrocytes. NP exposure activated microglia and reduced myelin protein expression in oligodendrocytes. Moreover, maternal NP exposure increased the numbers of microglia and oligodendrocytes in the cerebral cortex of adult offspring. NP exposure caused anxiety- and depressive-like behaviors in adult mice. Collectively, these findings suggest that maternal NP exposure negatively affects the brain development in adult offspring mice.

Capsaicin sensitizes malignant glioma cells to TRAIL-mediated apoptosis via DR5 upregulation and survivin downregulation.

Capsaicin, a pungent ingredient of red chili peppers, has been reported to possess antitumor activities. Here, we show that subtoxic doses of capsaicin effectively sensitize multiple malignant glioma cell lines to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis. Although TRAIL alone mediated partial proteolytic processing of procaspase-3 in glioma cells, cotreatment with capsaicin and TRAIL efficiently restored complete activation of caspases. We found that treatment of various gliomas with capsaicin significantly upregulated DR5, a death receptor of TRAIL, and downregulated the caspase inhibitor survivin. The induction of DR5 was mediated by CHOP/GADD153. The reduction in survivin protein level was associated with downregulation of cyclin B and Cdc2 expression, suggesting that inhibition of Cdc2 activity might contribute to capsaicin-induced survivin downregulation. Taken together, these results indicate that the activity of capsaicin toward DR5 and survivin contributes to the amplification of caspase cascades, thereby restoring TRAIL sensitivity in malignant glioma cells. Interestingly, normal astrocytes were resistant to combined treatment with capsaicin and TRAIL. Neither capsaicin-induced DR5 upregulation/survivin downregulation nor the partial processing of procaspase-3 by TRAIL was induced in astrocytes. Thus, a combined regimen using capsaicin and TRAIL may provide a safe and effective strategy for treating malignant gliomas.

Silibinin sensitizes human glioma cells to TRAIL-mediated apoptosis via DR5 up-regulation and down-regulation of c-FLIP and survivin.

Silibinin, a flavonoid isolated from Silybum marianum, has been reported to have cancer chemopreventive and therapeutic effects. Here, we show that treatment with subtoxic doses of silibinin in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces rapid apoptosis in TRAIL-resistant glioma cells, but not in human astrocytes, suggesting that this combined treatment may offer an attractive strategy for safely treating gliomas. Although the proteolytic processing of procaspase-3 by TRAIL was partially blocked in glioma cells, cotreatment with silibinin efficiently recovered TRAIL-induced caspase activation in these cells. Silibinin treatment up-regulated DR5, a death receptor of TRAIL, in a transcription factor CHOP-dependent manner. Furthermore, treatment with silibinin down-regulated the protein levels of the antiapoptotic proteins FLIP(L), FLIP(S), and survivin through proteasome-mediated degradation. Taken together, our results show that the activity of silibinin to modulate multiple components in the death receptor-mediated apoptotic pathway is responsible for its ability to recover TRAIL sensitivity in TRAIL-resistant glioma cells.

RNAi Screening-based Identification of USP10 as a Novel Regulator of Paraptosis.

Accumulating reports demonstrate that apoptosis does not explain all the effects of cancer therapy due to the innate and acquired apoptotic resistance of malignant cancer cells. Recently, paraptosis, a type of programmed cell death accompanied by dilation of mitochondria and/or the endoplasmic reticulum (ER), has garnered interest in cancer research as an alternative way to kill apoptosis-resistant cancers. We describe here the adaptation and validation of a high-content cell-based assay to screen and identify novel paraptotic regulators employing the malignant breast cancer cells undergoing curcumin-induced paraptosis. We used YFP-Mito cells, which express fluorescence selectively in mitochondria, to select paraptosis-related genes whose corresponding siRNAs appeared to modulate mitochondrial dilation, a morphological feature of paraptosis. From the selected 38 candidate genes, we chose ubiquitin specific peptidase 10 (USP10), a ubiquitin specific protease, as a strongly active candidate that warranted further evaluation of its involvement in paraptosis. We found that both siRNA-mediated knockdown of USP10 and treatment with the USP10 inhibitor, spautin-1, effectively attenuated curcumin-induced paraptosis. This systematic assay, in which a siRNA library is screened for the ability to ameliorate paraptotic changes in mitochondria, may enable researchers to identify potent regulators of paraptosis and new candidate genes/drugs to combat malignant breast cancer.

Quercetin sensitizes human hepatoma cells to TRAIL-induced apoptosis via Sp1-mediated DR5 up-regulation and proteasome-mediated c-FLIPS down-regulation.

This study demonstrates that combined treatment with subtoxic doses of quercetin (3',3',4',5,7-pentahydroxyflavone), a flavonoid found in many fruits and vegetables, plus tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces rapid apoptosis in TRAIL-resistant hepatocellular carcinoma (HCC) cells. Effective induction of apoptosis by the combined treatment with quercetin and TRAIL was not blocked by overexpression of Bcl-xL, which is known to confer resistance to various chemotherapeutic agents. These results suggest that this combined treatment may provide an attractive strategy for treating resistant HCCs. While the proteolytic processing of procaspase-3 by TRAIL was partially blocked in various HCC cells treated with TRAIL alone, co-treatment with quercetin efficiently recovered TRAIL-induced caspase activation. We found that quercetin treatment of HCC cells significantly up-regulated the mRNA and protein levels of DR5, a death receptor of TRAIL, in a transcription factor Sp1-dependent manner. Furthermore, treatment with quercetin significantly decreased the protein levels of c-FLIP, an inhibitor of caspase-8, through proteasome-mediated degradation. Finally, administration of small interfering RNA against DR5 or overexpression of c-FLIPS, but not c-FLIPL, significantly attenuated quercetin-stimulated TRAIL-induced apoptosis. Collectively, these findings show that quercetin recovers TRAIL sensitivity in various HCC cells via up-regulation of DR5 and down-regulation of c-FLIPS.

Robust dose-response curve estimation applied to high content screening data analysis.

BACKGROUND AND METHOD: Successfully automated sigmoidal curve fitting is highly challenging when applied to large data sets. In this paper, we describe a robust algorithm for fitting sigmoid dose-response curves by estimating four parameters (floor, window, shift, and slope), together with the detection of outliers. We propose two improvements over current methods for curve fitting. The first one is the detection of outliers which is performed during the initialization step with correspondent adjustments of the derivative and error estimation functions. The second aspect is the enhancement of the weighting quality of data points using mean calculation in Tukey's biweight function. RESULTS AND CONCLUSION: Automatic curve fitting of 19,236 dose-response experiments shows that our proposed method outperforms the current fitting methods provided by MATLAB®;'s nlinfit function and GraphPad's Prism software.

Release of Ca2+ from the endoplasmic reticulum and its subsequent influx into mitochondria trigger celastrol-induced paraptosis in cancer cells.

Celastrol, a triterpene extracted from the Chinese "Thunder of God Vine", is known to have anticancer activity, but its underlying mechanism is not completely understood. In this study, we show that celastrol kills several breast and colon cancer cell lines by induction of paraptosis, a cell death mode characterized by extensive vacuolization that arises via dilation of the endoplasmic reticulum (ER) and mitochondria. Celastrol treatment markedly increased mitochondrial Ca2+ levels and induced ER stress via proteasome inhibition in these cells. Both MCU (mitochondrial Ca2+ uniporter) knockdown and pretreatment with ruthenium red, an inhibitor of MCU, inhibited celastrol-induced mitochondrial Ca2+ uptake, dilation of mitochondria/ER, accumulation of poly-ubiquitinated proteins, and cell death in MDA-MB 435S cells. Inhibition of the IP3 receptor (IP3R) with 2-aminoethoxydiphenyl borate (2-APB) also effectively blocked celastrol-induced mitochondrial Ca2+ accumulation and subsequent paraptotic events. Collectively, our results show that the IP3R-mediated release of Ca2+ from the ER and its subsequent MCU-mediatedinflux into mitochondria critically contribute to celastrol-induced paraptosis in cancer cells.

Phenotypic MicroRNA Microarrays.

Microarray technology has become a very popular approach in cases where multiple experiments need to be conducted repeatedly or done with a variety of samples. In our lab, we are applying our high density spots microarray approach to microscopy visualization of the effects of transiently introduced siRNA or cDNA on cellular morphology or phenotype. In this publication, we are discussing the possibility of using this micro-scale high throughput process to study the role of microRNAs in the biology of selected cellular models. After reverse-transfection of microRNAs and siRNA, the cellular phenotype generated by microRNAs regulated NF-κB expression comparably to the siRNA. The ability to print microRNA molecules for reverse transfection into cells is opening up the wide horizon for the phenotypic high content screening of microRNA libraries using cellular disease models.