Role of ALDP (ABCD1) and mitochondria in X-linked adrenoleukodystrophy

Peroxisomal disorders have been associated with malfunction of peroxisomal metabolic pathways, but the pathogenesis of these disorders is largely unknown. X-linked adrenoleukodystrophy (X-ALD) is associated with elevated levels of very-long-chain fatty acids (VLCFA; C(>22:0)) that have been attributed to reduced peroxisomal VLCFA beta-oxidation activity. Previously, our laboratory and others have reported elevated VLCFA levels and reduced peroxisomal VLCFA beta-oxidation in human and mouse X-ALD fibroblasts. In this study, we found normal levels of peroxisomal VLCFA beta-oxidation in tissues from ALD mice with elevated VLCFA levels. Treatment of ALD mice with pharmacological agents resulted in decreased VLCFA levels without a change in VLCFA beta-oxidation activity. These data indicate that ALDP does not determine the rate of VLCFA beta-oxidation and that VLCFA levels are not determined by the rate of VLCFA beta-oxidation. The rate of peroxisomal VLCFA beta-oxidation in human and mouse fibroblasts in vitro is affected by the rate of mitochondrial long-chain fatty acid beta-oxidation. We hypothesize that ALDP facilitates the interaction between peroxisomes and mitochondria, resulting, when ALDP is deficient in X-ALD, in increased VLCFA accumulation despite normal peroxisomal VLCFA beta-oxidation in ALD mouse tissues. In support of this hypothesis, mitochondrial structural abnormalities were observed in adrenal cortical cells of ALD mice.     

Microglial Phagocytosis of Dopamine Neurons at Early Phases of Apoptosis

Transection of the medial forebrain bundle caused apoptosis of dopamine neurons in the rat substantia nigra. Immunohistochemical localization of activated microglia and tyrosine hydroxylase in the axotomized substantia nigra showed that activation of microglia was rapid and OX-6 (MHC-II marker)-positive and ED1 (lysosomal phagocytic marker)-positive microglia were apposed to structurally intact tyrosine hydroxylase-positive dopamine neurons, indicating microglial phagocytosis of degenerating dopamine neurons. The occurrence of microglial phagocytosis at early stages of apoptosis may indicate the evolution of apoptosis into an irreversible state. Alternatively, interventions that suppress early activation of microglia might lead to novel mechanisms for neuron protection.     

Modeling and docking of the three-dimensional structure of the human melanocortin 4 receptor

A three-dimensional structure of the human melanocortin 4 receptor (hMC4R) is constructed in this study using a computer-aided molecular modeling approach. Human melanocortin 4 receptor is a G Protein-Coupled Receptor (GPCR). We structurally aligned transmembrane helices with bovine rhodopsin transmembrane domains, simulated both intracellular and extracellular loop domains on homologous loop regions in other proteins of known 3D structure and modeled the C terminus on the corresponding part of bovine rhodopsin. Then tandem minimization and dynamics calculations were run to refine the crude structure. The simulative model was tested by docking with a triplet peptide (RFF) ligand. It was found that the ligand is located among transmembrane regions TM3, TM4, TM5, and TM6 of hMC4R. In consistence with mutational and biochemical data, binding site is mainly formed as a hydrophobic and negatively charged pocket. The model constructed here might provide a structural framework for making rational predictions in relevant fields.     

Effect of dietary pectin on the production of immunoglobulins and cytokines by mesenteric lymph node lymphocytes in mouse colitis induced with dextran sulfate sodium

The present study explores the dietary effect of pectin on the MLN lymphocyte functions of mice with dextran sulfate sodium (DS)-induced colitis. We found that the immunoglobulin (Ig)A level in mesenteric lymph node (MLN) lymphocytes was high, while the IgE level was lower, in mice fed with pectin than in those fed with cellulose. Interestingly, the fecal IgA concentration of the pectin-fed mice was significantly higher than that of the cellulose-fed mice. The concentrations of interferon-gamma and interleukin (IL)-2 treated with concanavalin A (ConA) were significantly higher in the pectin-fed group than in the cellulose-fed group. Although dietary pectin did not affect the IL-4 and IL-10 levels, the activation-induced IL-4 and IL-10 secretion was lower in MLN cells of the pectin-fed mice than of the cellulose-fed mice following DS-induced colitis. Based on these findings, we propose that the effect of dietary pectin on mice with DS-induced colitis is mediated by the manipulation of Th1 cells. Furthermore, the inhibitory effect of IL-4 and IL-10 by dietary pectin may play an important role in promoting a change in Th1/Th2 balance toward Th1-dominant immunity.     

Effects of degree of hydrolysis and pH on the solubility of heme-iron enriched peptide in hemoglobin hydrolysate

Hemoglobin was hydrolyzed with Esperase and Flavourzyme as the endopeptidase and exopeptidase, respectively. The solubility of the heme-iron enriched peptide fraction decreased as the degree of hydrolysis of the hydrolysate increased. When the pH of a hydrolysate was adjusted to 5.0 after simultaneous hydrolysis with the two enzymes, the solubility of heme-iron enriched peptide was nearly zero, and 98% of the heme-iron enriched peptide fraction was recovered as a precipitate. These results indicated that an effective separation method for the production of heme-iron enriched peptide could be established by pH adjustment of the hemoglobin hydrolysate with high degree of hydrolysis.     

The effect of manipulating ecdysteroid signaling on embryonic eye development in the locust<Emphasis Type="Italic"> Schistocerca americana</Emphasis>

Adult body plan differentiation in holometabolous insects depends on global induction and control by ecdysteroid hormones during the final phase of postembryogenesis. Studies in Drosophila melanogaster and Manduca sexta have shown that this pertains also to the development of the compound eye retina. It is unclear whether the hormonal control of postembryonic eye development in holometabolous insects represents evolutionary novelty or heritage from hemimetabolous insects, which develop compound eyes during embryogenesis. We therefore investigated the effect of manipulating ecdysteroid signaling in cultured embryonic eye primordia of the American desert locust Schistocerca americana, in which ecdysteroid level changes are known to induce three rounds of embryonic molt. Although at a considerably reduced rate compared to in vivo development, early differentiation and terminal maturation of the embryonic retina was observed in culture even if challenged with the ecdysteroid antagonist cucurbitacin B. Supplementing cultures with 20-hydroxyecdysone (20E) accelerated differentiation and maturation, and enhanced cell proliferation. Considering these results, and the relation between retina differentiation and ecdysteroid level changes during locust embryogenesis, we conclude that ecdysteroids are not an essential but possibly a modulatory component of embryonic retina development in S. americana. We furthermore found evidence that 20E initiated precocious epithelial morphogenesis of the posterior retinal margin indicating a more general role of ecdysteroids in insect embryogenesis.Electronic Supplementary Material Supplementary material is available in the online version of this article at Edited by C. Desplan     

Sol-gel-derived titanium oxide/copolymer composite based glucose biosensor

A new type of sol-gel-derived titanium oxide/copolymer composite material was developed and used for the construction of glucose biosensor. The composite material merged the best properties of the inorganic species, titanium oxide and the organic copolymer, poly(vinyl alcohol) grafting 4-vinylpyridine (PVA-g-PVP). The glucose oxidase entrapped in the composite matrix retained its bioactivity. Morphologies of the composite-modified electrode and the enzyme electrode were characterized with a scanning electron microscope. The dependence of the current responses on enzyme-loading and pH was studied. The response time of the biosensor was < 20 s and the linear range was up to 9 microM with a sensitivity of 405 nA/microM. The biosensor was stable for at least 1 month. In addition, the tetrathiafulvalene-mediated enzyme electrode was constructed for the decrease of detection potential and the effect of three common physiological sources that might interfere was also investigated.     

The removal by crab shell of mixed heavy metal ions in aqueous solution

In order to examine the inhibition effect of other heavy metal ions on the removal by crab shell of heavy metal ions in aqueous solutions, three ions (Pb(2+), Cd(2+), Cr(3+)) were used in single, binary and ternary systems. In single heavy metal ion systems, the removals of Cr(3+) and Pb(2+) were much higher than that of Cd(2+). In binary heavy metal ions systems, Cd(2+) did not affect Pb(2+) removal while Cr(3+) had a severe inhibition effect on the removal of Pb(2+). Cd(2+) removal was slightly affected by the presence of Pb(2+); however, it was severely affected by the presence of Cr(3+). The inhibitory effect of Cd(2+) on Cr(3+) was relatively lower than that of Pb(2+).     

Characterization of ligands for galectins, natural galactoside-binding immunoglobulin G subfractions and sarcolectin and also of the expression of calcyclin in thyroid lesions

The purpose of this study was to characterize ligands for galectins, natural galactoside-binding immunoglobulin G subfractions and sarcolectin and also the expression of calcyclin in various benign and malignant thyroid lesions. The extent of the binding of eight glycochemical probes was quantitatively assessed using computer-assisted microscopy on 76 thyroid lesions including 10 not-otherwise-specified multinodular goiters (S_MNG), 11 multinodular goiters with adenomatous hyperplasia (AH_MNG), 8 normomacrovesicular (NM_ADE) and 12 microvesicular (MIC_ADE) adenomas, and 9 papillary (P_CAR), 10 follicular variants of papillary (FvarP_CAR), 7 follicular (F_CAR) and 9 anaplastic (A_CAR) carcinomas. The 8 histochemical probes included 5 animal lectins (including galectins and sarcolectin), 1 polyclonal antibody (raised against calcyclin) and 2 immunoglobulin G subfractions from human serum with selectivity to alpha- and beta-galactosyl residues. The results show that multinodular goiters with adenomatous hyperplasia exhibited histochemical characteristics intermediate to those of normal multinodular goiters and microvesicular adenomas. Normomacrovesicular adenomas behaved very distinctly from microvesicular ones. Microvesicular adenomas were more closely related to differentiated thyroid carcinomas than any other type of benign thyroid lesions of epithelial origin. Papillary and follicular carcinomas seemed to represent the two extremes of the same biological entity with the follicular variant of the papillary carcinoma serving as a biological link between these two extremes. Anaplastic carcinomas behaved in a significantly different manner when compared to the differentiated forms of thyroid carcinomas. The results suggest that the patterns of expression of the glycoconjugates investigated in the present study may constitute useful tools for characterizing lesions in the human thyroid.