The Effect of Psyllium Hydrocolloid and Cholestyramine on Hepatic Bile Lipid Composition in Man

The effects of a mucoid - psyllium hydrocolloid - and an anion exchange polymercholestryamine - on the total cholesterol, total phospholipid, total bile salt, cholate, chenodeoxycholate, and deoxycholate concentrations of hepatic bile were determined in six post-cholecystectomy patients. Bile was obtained by drainage through an indwelling T-tube, which was clamped except during bile collection. Psyllium hydrocolloid treatment (12 gm/day) for 6 to 29 days had little or no effect on the cholesterol or phospholipid concentration of hepatic bile, but increased the total bile salt pool by gradually increasing the concentration of deoxycholate. Cholestyramine treatment (12 gm/day) for 8 to 12 days had no significant effect on cholesterol, phospholipid or total bile salt concentrations. There was a significant increase in the tri- to di-hydroxy bile salt ratio due to decreases in chenodeoxycholate and deoxycholate concentrations. The ratio of taurine to glycine conjugates decreased because of reductions in concentrations of taurine conjugates and compensating increases in glycine conjugates. The influence of these changes on bile micelle stability and cholesterol solubility is discussed. It is concluded that the changes effected by psyllium hydrocolloid may result in more stable bile micelles and greater cholesterol solubility. No definite conclusions can be reached with respect to cholestyramine\u27s effects

An experiment of the combined treatment of traditional Lei-huo-jiu therapy with Chinese medicine for the lacrimal gland of Sjögren’s syndrome

This experiment chooses nonobese diabetic (NOD) mouse as the animal model of Sjögren’s syndrome and investigates the morphologic changes, the expression of inflammatory factors and growth factors of this mouse’s lacrimal gland in response to a combined treatment of traditional Lei-huo-jiu therapy alone and in combination with Chinese medicine. The methods were to (1) use a morphological approach to directly observe pathological changes of the lacrimal gland in response to combined treatment and (2) to detect the level of tumor necrosis factor (TNF)-α, interleukin (IL)-1, and nuclear factor kappa B (NF-κB) in lacrimal gland tissue caused by the combined treatments using a immunohistochemical approach. There is a reduction of the mast cell’s degranulation and modulation of the level of cytokines in TNF-α, IL-1, and NF-κB in the combined therapy group. The combined treatment of traditional Lei-huo-jiu therapy with Chinese medicine can improve the pathological changes of the lacrimal gland tissue of the NOD mouse through modulating the level of TNF-α, IL-1, and NF-κB which results in improved tear secretion and function of the lacrimal gland

Pharmacological screening using an FXN-EGFP cellular genomic reporter assay for the therapy of Friedreich ataxia

Copyright @ 2013 Li et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Friedreich ataxia (FRDA) is an autosomal recessive disorder characterized by neurodegeneration and cardiomyopathy. The presence of a GAA trinucleotide repeat expansion in the first intron of the FXN gene results in the inhibition of gene expression and an insufficiency of the mitochondrial protein frataxin. There is a correlation between expansion length, the amount of residual frataxin and the severity of disease. As the coding sequence is unaltered, pharmacological up-regulation of FXN expression may restore frataxin to therapeutic levels. To facilitate screening of compounds that modulate FXN expression in a physiologically relevant manner, we established a cellular genomic reporter assay consisting of a stable human cell line containing an FXN-EGFP fusion construct, in which the EGFP gene is fused in-frame with the entire normal human FXN gene present on a BAC clone. The cell line was used to establish a fluorometric cellular assay for use in high throughput screening (HTS) procedures. A small chemical library containing FDA-approved compounds and natural extracts was screened and analyzed. Compound hits identified by HTS were further evaluated by flow cytometry in the cellular genomic reporter assay. The effects on FXN mRNA and frataxin protein levels were measured in lymphoblast and fibroblast cell lines derived from individuals with FRDA and in a humanized GAA repeat expansion mouse model of FRDA. Compounds that were established to increase FXN gene expression and frataxin levels included several anti-cancer agents, the iron-chelator deferiprone and the phytoalexin resveratrol.Muscular Dystrophy Association (USA), the National Health and Medical Research Council (Australia), the Friedreich’s Ataxia Research Alliance (USA), the Brockhoff Foundation (Australia), the Friedreich Ataxia Research Association (Australasia), Seek A Miracle (USA) and the Victorian Government’s Operational Infrastructure Support Program

Advances of the FRIB project

The Facility for Rare Isotope Beams (FRIB) Project has entered the phase of beam commissioning starting from the room-temperature front end and the superconducting linac segment of first 15 cryomodules. With the newly commissioned helium refrigeration system supplying 4.5K liquid helium to the quarter-wave resonators and solenoids, the FRIB accelerator team achieved the sectional key performance parameters as designed ahead of schedule accelerating heavy ion beams above 20MeV/u energy. Thus, FRIB accelerator becomes world's highest-energy heavy ion linear accelerator. We also validated machine protection and personnel protection systems that will be crucial to the next phase of commissioning. FRIB is on track towards a national user facility at the power frontier with a beam power two orders of magnitude higher than operating heavy-ion facilities. This paper summarizes the status of accelerator design, technology development, construction, commissioning as well as path to operations and upgrades

Substrate docking to γ-secretase allows access of γ-secretase modulators to an allosteric site

γ-Secretase generates the peptides of Alzheimer's disease, Aβ40 and Aβ42, by cleaving the amyloid precursor protein within its transmembrane domain. γ-Secretase also cleaves numerous other substrates, raising concerns about γ-secretase inhibitor off-target effects. Another important class of drugs, γ-secretase modulators, alter the cleavage site of γ-secretase on amyloid precursor protein, changing the Aβ42/Aβ40 ratio, and are thus a promising therapeutic approach for Alzheimer's disease. However, the target for γ-secretase modulators is uncertain, with some data suggesting that they function on γ-secretase, whereas others support their binding to the amyloid precursor. In this paper we address this controversy by using a fluorescence resonance energy transfer-based assay to examine whether γ-secretase modulators alter Presenilin-1/γ-secretase conformation in intact cells in the absence of its natural substrates such as amyloid precursor protein and Notch. We report that the γ-secretase allosteric site is located within the γ-secretase complex, but substrate docking is needed for γ-secretase modulators to access this site

Evidence for a Common Mechanism of SIRT1 Regulation by Allosteric Activators

A molecule that treats multiple age-related diseases would have a major impact on global health and economics. The SIRT1 deacetylase has drawn attention in this regard as a target for drug design. Yet controversy exists around the mechanism of sirtuin-activating compounds (STACs). We found that specific hydrophobic motifs found in SIRT1 substrates such as PGC-1α and FOXO3a facilitate SIRT1 activation by STACs. A single amino acid in SIRT1, Glu[superscript 230], located in a structured N-terminal domain, was critical for activation by all previously reported STAC scaffolds and a new class of chemically distinct activators. In primary cells reconstituted with activation-defective SIRT1, the metabolic effects of STACs were blocked. Thus, SIRT1 can be directly activated through an allosteric mechanism common to chemically diverse STACs.Glenn Foundation for Medical ResearchEllison Medical FoundationJuvenile Diabetes Research Foundation InternationalUnited Mitochondrial Disease FoundationNational Institutes of Health (U.S.)National Institute of Allergy and Infectious Diseases (U.S.

Gender- and Age-Dependent γ-Secretase Activity in Mouse Brain and Its Implication in Sporadic Alzheimer Disease

Alzheimer disease (AD) is an age-related disorder. Aging and female gender are two important risk factors associated with sporadic AD. However, the mechanism by which aging and gender contribute to the pathogenesis of sporadic AD is unclear. It is well known that genetic mutations in γ-secretase result in rare forms of early onset AD due to the aberrant production of Aβ42 peptides, which are the major constituents of senile plaques. However, the effect of age and gender on γ-secretase has not been fully investigated. Here, using normal wild-type mice, we show mouse brain γ-secretase exhibits gender- and age-dependent activity. Both male and female mice exhibit increased Aβ42∶Aβ40 ratios in aged brain, which mimics the effect of familial mutations of Presenilin-1, Presenlin-2, and the amyloid precursor protein on Aβ production. Additionally, female mice exhibit much higher γ-secretase activity in aged brain compared to male mice. Furthermore, both male and female mice exhibit a steady decline in Notch1 γ-secretase activity with aging. Using a small molecule affinity probe we demonstrate that male mice have less active γ-secretase complexes than female mice, which may account for the gender-associated differences in activity in aged brain. These findings demonstrate that aging can affect γ-secretase activity and specificity, suggesting a role for γ-secretase in sporadic AD. Furthermore, the increased APP γ-secretase activity seen in aged females may contribute to the increased incidence of sporadic AD in women and the aggressive Aβ plaque pathology seen in female mouse models of AD. In addition, deceased Notch γ-secretase activity may also contribute to neurodegeneration. Therefore, this study implicates altered γ-secretase activity and specificity as a possible mechanism of sporadic AD during aging

Resveratrol, by Modulating RNA Processing Factor Levels, Can Influence the Alternative Splicing of Pre-mRNAs

Alternative pre-mRNA splicing defects can contribute to, or result from, various diseases, including cancer. Aberrant mRNAs, splicing factors and other RNA processing factors have therefore become targets for new therapeutic interventions. Here we report that the natural polyphenol resveratrol can modulate alternative splicing in a target-specific manner. We transfected minigenes of several alternatively spliceable primary mRNAs into HEK293 cells in the presence or absence of 1, 5, 20 and 50 µM resveratrol and measured exon levels by semi-quantitative PCR after separation by agarose gel electrophoresis. We found that 20 µg/ml and 50 µg/ml of resveratrol affected exon inclusion of SRp20 and SMN2 pre-mRNAs, but not CD44v5 or tau pre-mRNAs. By Western blotting and immunofluorescence we showed that this effect may be due to the ability of resveratrol to change the protein level but not the localization of several RNA processing factors. The processing factors that increased significantly were ASF/SF2, hnRNPA1 and HuR, but resveratrol did not change the levels of RBM4, PTBP1 and U2AF35. By means of siRNA-mediated knockdown we depleted cells of SIRT1, regarded as a major target of resveratrol, and showed that the effect on splicing was not dependent on SIRT1. Our results suggest that resveratrol might be an attractive small molecule to treat diseases in which aberrant splicing has been implicated, and justify more extensive research on the effects of resveratrol on the splicing machinery