Endothelial dysfunction induces atherosclerosis: increased aggrecan expression promotes apoptosis in vascular smooth muscle cells.

Endothelial dysfunction-induced lipid retention is an early feature of atherosclerotic lesion formation. Apoptosis of vascular smooth muscle cells (VSMCs) is one of the major modulating factors of atherogenesis, which accelerates atherosclerosis progression by causing plaque destabilization and rupture. However, the mechanism underlying VSMC apoptosis mediated by endothelial dysfunction in relation to atherosclerosis remains elusive.

Enhancement of liposome mediated gene transfer by adding cholesterol and cholesterol modulating drugs.

Cholesterol is an important cell membrane component and has been used as co-lipid for cationic liposome to enhance gene delivery. However, the role of cholesterol in transfection efficiency has not been fully understood. In this study, transfection efficiency of liposome was measured after cholesterol was added to the cell culture medium.

Perfusion Assessment Using Intravoxel Incoherent Motion-Based Analysis of Diffusion-Weighted Magnetic Resonance Imaging: Validation Through Phantom Experiments.

Objectives: The aims of this study were to demonstrate the theoretical meaning of intravoxel incoherent motion (IVIM) parameters and to compare the robustness of 2 biexponential fitting methods through magnetic resonance experiments using IVIM phantoms.

Materials And Methods: Intravoxel incoherent motion imaging was performed on a 3 T magnetic resonance imaging scanner using 15 b values (0-800 s/mm) for 4 phantoms with different area fractions of the flowing water compartment (FWC%), at the infusion flow rates of 0, 1, 2, and 3 mL/min. Images were quantitatively analyzed using monoexponential free biexponential, and segmented biexponential fitting models.

Multivalent di-nucleosome recognition enables the Rpd3S histone deacetylase complex to tolerate decreased H3K36 methylation levels.

The Rpd3S histone deacetylase complex represses cryptic transcription initiation within coding regions by maintaining the hypo-acetylated state of transcribed chromatin. Rpd3S recognizes methylation of histone H3 at lysine 36 (H3K36me), which is required for its deacetylation activity. Rpd3S is able to function over a wide range of H3K36me levels, making this a unique system to examine how chromatin regulators tolerate the reduction of their recognition signal.

Sitagliptin increases tau phosphorylation in the hippocampus of rats with type 2 diabetes and in primary neuron cultures.

Increasing evidence supports an association between Alzheimer's disease (AD) and diabetes. In this context, anti-diabetic agents such as rosiglitazone and glucagon-like peptide (GLP)-1 have been reported to reduce pathologies associated with AD, including tau hyperphosphorylation, suggesting that such agents might be used to treat AD. One such anti-diabetic agent is sitagliptin, which acts through inhibition of dipeptidyl peptidase (DPP)-IV to increase GLP-1 levels.

Reconstitution of modified chromatin templates for in vitro functional assays.

To study the functions of histone modifications in the context of chromatin, it is necessary to be able to prepare nucleosomal templates that carry specific posttranslational modifications in a defined biochemical system. Here, we describe two sets of protocols for reconstituting designer nucleosomes that contain specifically modified histones. The resulting nucleosomes are suitable for electromobility shift assays, chromatin remodeling assays, and other functional and structural studies.

Structural basis of cooperativity in human UDP-glucose dehydrogenase.

Background: UDP-glucose dehydrogenase (UGDH) is the sole enzyme that catalyzes the conversion of UDP-glucose to UDP-glucuronic acid. The product is used in xenobiotic glucuronidation in hepatocytes and in the production of proteoglycans that are involved in promoting normal cellular growth and migration. Overproduction of proteoglycans has been implicated in the progression of certain epithelial cancers, while inhibition of UGDH diminished tumor angiogenesis in vivo.

PICH and BLM limit histone association with anaphase centromeric DNA threads and promote their resolution.

Centromeres nucleate the formation of kinetochores and are vital for chromosome segregation during mitosis. The SNF2 family helicase PICH (Plk1-interacting checkpoint helicase) and the BLM (the Bloom's syndrome protein) helicase decorate ultrafine histone-negative DNA threads that link the segregating sister centromeres during anaphase. The functions of PICH and BLM at these threads are not understood, however.

Inhibitory effects of gallic acid and quercetin on UDP-glucose dehydrogenase activity.

We have examined polyphenols as potential inhibitors of UDP-glucose dehydrogenase (UGDH) activity. Gallic acid and quercetin decreased specific activities of UGDH and inhibited the proliferation of MCF-7 human breast cancer cells. Western blot analysis showed that gallic acid and quercetin did not affect UGDH protein expression, suggesting that UGDH activity is inhibited by polyphenols at the post-translational level.

Soluble expression and purification of synthetic human bone morphogenetic protein-2 in Escherichia coli.

A 345-bp gene that encodes human bone morphogenetic protein-2 (hBMP-2) has been synthesized. The codon usage of the resulting gene was modified to include those triplets that are utilized in highly expressed Escherichia coli genes. The hBMP-2 gene was efficiently expressed in E.

Small-interfering-RNA-mediated silencing of human glutamate dehydrogenase induces apoptosis in neuroblastoma cells.

In the nervous system, GDH (glutamate dehydrogenase) is enriched in astrocytes and is important for recycling glutamate, a major excitatory neurotransmitter. The function of hGDH (human GDH) may be important in neurodegenerative diseases such as Parkinson's disease. To test the effect of decreased hGDH expression, several vector-based plasmidlinked hGDH siRNAs (small interfering RNAs) were expressed intracellularly in BE(2)C human neuroblastoma cells.

Alteration of the quaternary structure of human UDP-glucose dehydrogenase by a double mutation.

There are conflicting views for the polymerization process of human UDP-glucose dehydrogenase (UGDH) and no clear evidence has been reported yet. Based on crystal coordinates for Streptococcus pyogenes UGDH, we made double mutant A222Q/S233G. The double mutagenesis had no effects on expression, stability, and secondary structure.

Protective effect of benzothiazole derivative KHG21834 on amyloid beta-induced neurotoxicity in PC12 cells and cortical and mesencephalic neurons.

We have investigated the effect of KHG21834, a benzothiazole derivative, on the amyloid beta protein (Abeta)-induced cell death in rat pheochromocytoma (PC12) cells and rat cortical and mesencephalic neuron-glia cultures. KHG21834 attenuated the Abeta(25-35)-induced apoptotic death in PC12 cells determined by characteristic morphological alterations and positive in situ terminal end-labeling (TUNEL). In the cortical neuron-glia cultures, KHG21834 reduced the Abeta(25-35)-induced apoptosis determined by TUNEL staining.

Amino acid changes within antenna helix are responsible for different regulatory preferences of human glutamate dehydrogenase isozymes.

Human glutamate dehydrogenase (hGDH) exists in hGDH1 (housekeeping isozyme) and in hGDH2 (nerve-specific isozyme), which differ markedly in their allosteric regulation. Because they differ in only 16 of their 505 amino acids, the regulatory preferences must arise from amino acid residues that are not common between hGDH1 and hGDH2. To our knowledge none of the mutagenesis studies on the hGDH isozymes to date have identified the amino acid residues fully responsible for the different regulatory preferences between hGDH1 and hGDH2.

Expression, purification, crystallization, and preliminary X-Ray analysis of the human UDP-glucose dehydrogenase.

UDP-glucose dehydrogenase (UGDH) catalyzes the synthesis of UDP-glucuronic acid from UDP-glucose resulting in the formation of proteoglycans that are involved in promoting normal cellular growth and migration. Overproduction of proteoglycans has been implicated in the progression of certain epithelial cancers. Here, human UGDH (hUGDH) was purified and crystallized from a solution of 0.

Calpain activation in okadaic-acid-induced neurodegeneration.

Calpain activation has been implicated in the pathogenesis of Alzheimer's disease. Okadaic acid, a protein phosphatase-2A inhibitor, has been used in Alzheimer's disease research models to increase tau phosphorylation and induce neuronal death. We previously reported that okadaic acid induced predominant activation of caspase-3 in immature neurons, but less activation in mature neurons.

Okadaic acid induces JNK activation, bim overexpression and mitochondrial dysfunction in cultured rat cortical neurons.

Apoptosis via tau phosphorylation has been implicated in the selective neuronal losses seen in Alzheimer's disease (AD). Previous studies in vivo and in cultured neurons have shown that okadaic acid (OA) evokes tau phosphorylation to initiate a neurodegeneration that resembles the pathogenesis of AD. In an effort to identify additional key molecules in this neurodegeneration, we treated cultured rat neurons with OA and examined the apoptosis-related effects, such as changes in mitochondrial activity and expression levels of JNK, Bim, Bad, Bax and caspase-3.

Inhibition of human UDP-glucose dehydrogenase expression using siRNA expression vector in breast cancer cells.

UDP-glucose dehydrogenase (UGDH) catalyzes two oxidations of UDP-glucose to yield UDP-glucuronic acid. Pathological over-production of extracellular matrix components may be linked to the availability of UDP-glucuronic acid, therefore UGDH is a potential therapeutic target. RNA interference (RNAi) has been adapted to knock down the expression of human UGDH.

Regulation of glutamate level in rat brain through activation of glutamate dehydrogenase by Corydalis ternata.

When treated with protopine and alkalized extracts of the tuber of Corydalis ternata for one year, significant decrease in glutamate level and increase in glutamate dehydrogenase (GDH) activity was observed in rat brains. The expression of GDH between the two groups remained unchanged as determined by Western and Northern blot analysis, suggesting a post-translational regulation of GDH activity in alkalized extracts treated rat brains. The stimulatory effects of alkalized extracts and protopine on the GDH activity was further examined in vitro with two types of human GDH isozymes, hGDH1 (house-keeping GDH) and hGDH2 (nerve-specific GDH).

Activation of monoamine oxidase isotypes by prolonged intake of aluminum in rat brain.

Rats were fed 100 microM aluminum maltolate for one year in their drinking water. Brain aluminum contents have increased 4.2-fold in the aluminum-treated group, whereas no significant changes in the body weight, brain weight, and brain protein content were observed.

Identification of ADP-ribosylation site in human glutamate dehydrogenase isozymes.

When the influence of ADP-ribosylation on the activities of the purified human glutamate dehydrogenase isozymes (hGDH1 and hGDH2) was measured in the presence of 100 microM NAD+ for 60 min, hGDH isozymes were inhibited by up to 75%. If incubations were performed for longer time periods up to 3 h, the inhibition of hGDH isozymes did not increased further. This phenomenon may be related to the reversibility of ADP-ribosylation in mitochondria.

Monastrol, a selective inhibitor of the mitotic kinesin Eg5, induces a distinctive growth profile of dendrites and axons in primary cortical neuron cultures.

Various factors including some motor proteins regulate microtubule (MT) transport and influence the formation of neuronal processes. Eg5, a slow and non-processive (+)-end directed motor molecule, is expressed in developing and differentiated neurons. However, how Eg5 works in neurons is still elusive.