Elevated cerebrospinal fluid lactate levels and the pathomechanism of calcification in Fahr's disease.

In this study, we report the case of a 68-year-old man complaining of involuntary movement of his left shoulder and lower jaw plus dyspnea. On cranial computed tomography and magnetic resonance imaging, marked and symmetrical calcification at the basal ganglia and dentate nuclei was documented. An elevated cerebrospinal fluid (CSF) lactate level was confirmed by spinal tap examination and magnetic resonance spectroscopy. The raised CSF lactate level, clinical characteristics such as diabetes, bilateral hearing loss and symmetrical cerebral calcification strongly suggested some kinds of mitochondrial disease. However, gene analysis of peripheral blood leukocytes revealed no typical or known mutations. Under the diagnosis of Fahr's disease, we treated him with haloperidol, which completely abolished his symptoms. In Ellsworth-Howard test, he showed markedly decreased phosphaturic response to parathyroid hormone with same pattern as type 2 pseudohypoparathyroidism. This abnormal response in our patient, probably due to respiratory alkalosis reflecting chronic hyperventilation, might in part explain similar mechanism of ectopic calcification underlying these two diseases.

Selective induction of DeltaFosB in the brain after transient forebrain ischemia accompanied by an increased expression of galectin-1, and the implication of DeltaFosB and galectin-1 in neuroprotection and neurogenesis.

Transient forebrain ischemia causes selective induction of DeltaFosB, an AP-1 (activator protein-1) subunit, in cells within the ventricle wall or those in the dentate gyrus in the rat brain prior to neurogenesis, followed by induction of nestin, a marker for neuronal precursor cells, or galectin-1, a beta-galactoside sugar-binding lectin. The adenovirus-mediated expression of FosB or DeltaFosB induced expression of nestin, glial fibrillary acidic protein and galectin-1 in rat embryonic cortical cells. DeltaFosB-expressing cells exhibited a significantly higher survival and proliferation after the withdrawal of B27 supplement than the control or FosB-expressing cells. The decline in the DeltaFosB expression in the survivors enhanced the MAP2 expression. The expression of DeltaFosB in cells within the ventricle wall of the rat brain also resulted in an elevated expression of nestin. We therefore conclude that DeltaFosB can promote the proliferation of quiescent neuronal precursor cells, thus enhancing neurogenesis after transient forebrain ischemia.

Galectin-1beta, a natural monomeric form of galectin-1 lacking its six amino-terminal residues promotes axonal regeneration but not cell death.

We previously identified a novel N-terminally processed form of galectin-1, galectin-1beta (Gal-1beta) whose expression was induced by DeltaFosB. In the present study, the biochemical properties and biological functions of Gal-1beta were compared with the full-length form of galectin-1 (Gal-1alpha). We first purified recombinant mouse Gal-1alpha and beta (rmGal-1alpha, beta) to near homogeneity. The rmGal-1alpha exists as a monomer under oxidized conditions and forms a dimer under reduced conditions, while the rmGal-1beta exists as a monomer regardless of redox conditions. The affinity of rmGal-1beta to beta-lactose was approximately two-fold lower than that of rmGal-1alpha under reduced conditions. The viability of Jurkat cells efficiently decreased when they were exposed to rmGal-1alpha, however, rmGal-1beta barely induced such a reduction. In contrast, both rmGal-1alpha and rmGal-1beta exhibited an equivalent capacity to promote axonal regeneration from the dorsal root ganglion explants. Our results suggest that the biochemical properties of rmGal-1beta determine its biological functions.

Preparation of enantiomerically pure 2'-substituted 2-diphenylphosphino-1,1'-binaphthyls by reductive cleavage of the carbon-phosphorus bond in a borane complex of 2-diphenylphosphino-2'-diphenylphosphinyl-1,1'-binaphthyl.

Reaction of (S)-2'-boranatodiphenylphosphino-2-diphenylphosphinyl-1,1'-binaphthyl (3, borane complex of BINAP monoxide) with an excess of n-butyllithium in THF at -78 degrees C brought about a selective cleavage of the carbon-phosphorus bond between the binaphthyl and diphenylphosphinyl groups to generate the binaphthyllithium 14, the treatment of which with electrophiles MeOD, I(2), and ClSnMe(3) gave, after removal of the borane, the corresponding 2'-substituted 2-diphenylphosphino-1,1'-binaphthyls (E-MOP 9: E = D, I, SnMe(3)), without loss of the enantiomeric purity.

Surface expression and rapid internalization of macrosialin (mouse CD68) on elicited mouse peritoneal macrophages.

Macrosialin, the mouse homolog of human CD68, is a heavily glycosylated transmembrane protein found almost exclusively in macrophages. Its function remains uncertain. It has a high affinity for oxidized low-density lipoprotein (LDL) in ligand blots and antibodies against the human homolog, CD68, inhibit the binding of oxidized LDL to a human monocyte-derived cell line (THP-1). However, there is still controversy as to whether macrosialin, found predominantly in late endosomes, is expressed at all on the plasma membrane. The present studies, done in thioglycollate-elicited peritoneal macrophages, confirm that macrosialin is predominantly intracellular but show clearly that 10-15% of it is expressed on the cell surface. Exchange with intracellular pools occurs at an extremely high rate. The results are compatible with a surface function, including internalization of bound ligands or adhesion to surfaces.

Comparison of the effect of bezafibrate on improvement of atherogenic lipoproteins in Japanese familial combined hyperlipidemic patients with or without impaired glucose tolerance.

The effect of bezafibrate on plasma lipoproteins was investigated in Japanese familial combined hyperlipidemic patients with or without an impaired glucose tolerance accompanied by a low-density lipoprotein subclass, with the major gradient gel peak at a particle diameter of less than 25.5 nm. Bezafibrate treatment at a dose of 400 mg/d for 12 weeks produced an antiatherogenic effect on lipoprotein profiles, as reflected by a decrease in plasma triglyceride levels, an increase in plasma high-density lipoprotein-cholesterol levels, induction of the large-size subclass of low-density lipoprotein, and disappearance of intermediate-density lipoproteins. The plasma total and low-density lipoprotein-cholesterol-lowering effect of bezafibrate was significant in patients without impaired glucose tolerance but was not significant in patients with impaired glucose tolerance. Bezafibrate increased lipoprotein lipase activity and decreased the activity of cholesteryl ester transfer protein, both in patients with or without impaired glucose tolerance. There was no difference in the distribution of signal peptide insertion/deletion or Xbal polymorphisms of the apolipoprotein B gene in patients with or without impaired glucose tolerance. Mechanisms other than lipoprotein lipase, cholesteryl ester transfer protein activities, and an apolipoprotein B gene polymorphism may be responsible for the resistance to lowering of plasma total and low-density lipoprotein cholesterol levels with bezafibrate treatment in familial combined hyperlipidemic patients with impaired glucose tolerance.

Pentaerythritol tetranicotinate (niceritrol) decreases plasma lipoprotein(a) levels.

We determined the most effective dosage of pentaerythritol tetranicotinate (niceritrol) to reduce plasma lipoprotein(a) [Lp(a)] levels in 44 Japanese patients (16 men and 28 women; mean age, 59.2 +/- 10.8 years) with hyperlipidemia types IIa, IIb, and IV. Patients received oral niceritrol at a dosage of 750 mg (3 tablets)/d for 8 weeks, followed by 1,500 mg (6 tablets)/d for 8 weeks. Administration of niceritrol 750 mg/d for 8 weeks decreased total and low-density lipoprotein (LDL) cholesterol in patients with type IIa hyperlipidemia and decreased triglycerides in patients with type IV hyperlipidemia, but did not affect Lp(a). However, niceritrol 1,500 mg/d for 8 weeks decreased Lp(a) in patients with initial Lp(a) levels greater than 30 mg/dL in addition to decreasing total and LDL cholesterol and triglycerides. These results suggest that the effective dosage of niceritrol to reduce the serum Lp(a) concentration in Japanese hyperlipidemic patients with a high Lp(a) level (> or = 30 mg/dL) is greater than 1,500 mg/d.

Opposite effects on cholesterol metabolism and their mechanisms induced by dietary oleic acid and palmitic acid in hamsters.

The effects of dietary oleic acid on cholesterol metabolism were investigated and compared with those of palmitic acid in hamsters. Addition of 5% oleic acid to a 0.1% cholesterol-supplemented diet decreased plasma total cholesterol, very low density lipoprotein (VLDL) cholesterol, and low density lipoprotein (LDL) cholesterol, increased hepatic LDL receptor activity, and decreased plasma cholesteryl ester transfer protein (CETP) activity in comparison with 0.1% cholesterol alone. In contrast, addition of 5% palmitic acid to a 0.1% cholesterol-supplemented diet increased total cholesterol and LDL-cholesterol, increased plasma CETP activity, and suppressed hepatic LDL receptor activity to a greater extent than 0.1% cholesterol alone. Neither oleic acid nor palmitic acid altered hepatic microsomal 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity, but oleic acid increased hepatic microsomal cholesterol 7 alpha-hydroxylase activity. These results suggest that dietary oleic acid inhibits the increases in total, VLDL-, and LDL-cholesterol induced by dietary cholesterol by preventing both LDL receptor suppression and increased CETP activity, whereas dietary palmitic acid augments the cholesterol-induced increases in total and LDL-cholesterol by both further suppression of LDL receptor activity and further stimulation of CETP activity.

Comparison of hypocholesterolemic effects induced by dietary linoleic acid and oleic acid in hamsters.

We investigated the differences between the hypocholesterolemic effects induced by dietary linoleic acid and those induced by oleic acid in hamsters. Addition of 5% linoleic acid or oleic acid to a 0.1% cholesterol-supplemented diet diminished the increases in plasma total and low density lipoprotein (LDL) cholesterol induced by cholesterol alone. Linoleic acid decreased high density lipoprotein (HDL) cholesterol in comparison with cholesterol alone, whereas oleic acid did not. As compared with a standard diet or a cholesterol-supplemented diet, linoleic acid and oleic acid each prevented hepatic LDL receptor suppression, although linoleic acid was more effective. Oleic acid prevented the increase in plasma cholesteryl ester transfer protein (CETP) activity induced by dietary cholesterol, whereas linoleic acid did not. Neither linoleic acid nor oleic acid altered hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity. Only oleic acid increased hepatic cholesterol 7 alpha-hydroxylase activity. These results suggest that dietary linoleic and oleic acids diminish the cholesterol-induced increases in plasma total and LDL-cholesterol by preventing hepatic LDL receptor suppression, and in the case of oleic acid by also preventing the increase in the plasma CETP activity. These effects on cholesterol 7 alpha-hydroxylase activity may influence bile lipid metabolism.

Effect of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase, acyl-coenzyme A: cholesterol acyltransferase, and bile lipid secretion in the hamster with intact enterohepatic circulation.

The effects of administration of pravastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, on hepatic cholesterol 7 alpha-hydroxylase and acyl-coenzyme A: cholesterol acyltransferase (ACAT) activities and bile lipid secretion were investigated in Syrian golden hamsters. Continuous administration of pravastatin induced no significant changes in hepatic cholesterol content, ACAT and cholesterol 7 alpha-hydroxylase activities, or bile lipid and acid composition. Abrupt withdrawal of pravastatin induced increases in hepatic cholesterol content and ACAT activity and no change in hepatic cholesterol 7 alpha-hydroxylase activity, and increased cholesterol saturation in bile. Hepatic cholesterol 7 alpha-hydroxylase activity paralleled hepatic mRNA levels of this enzyme. These results suggest that a change in hepatic cholesterol metabolism induced by continuous administration of pravastatin maintains a constant net balance of hepatic cholesterol content. In addition, the drug has no deleterious influence on metabolism of bile lipids and acids and related enzymes, except for a transient increase in cholesterol saturation in bile induced by an inappropriate increase in hepatic cholesterol content and a lack of response of cholesterol 7 alpha-hydroxylase activity to changes in hepatic cholesterol content upon abrupt withdrawal of pravastatin.

Identification of a functional receptor differing from the LDL receptor that catabolizes chylomicron remnant in Hep G2 cells.

We investigated types of lipoprotein receptors on Hep G2 cells using a monoclonal antibody against the LDL receptor. IgG-C7 inhibited the binding and internalization of 125I-labeled low density lipoprotein (LDL) in Hep G2 cells with upregulated and downregulated LDL receptors by 90% of control values. Binding and internalization of 125I-labeled chylomicron remnant in Hep G2 cells with upregulated and downregulated LDL receptors was 50% and 85%, respectively, of control values after exposure to IgG-C7. Excess unlabeled chylomicron remnant inhibited binding and internalization of 125I-labeled chylomicron remnant in Hep G2 cells with downregulated LDL receptors completely. Pronase treatment abolished binding and internalization of 125I-labeled LDL and 125I-labeled chylomicron remnant in Hep G2 cells. When solubilized fractions of Hep G2 cells were immunoprecipitated with IgG-C7, the binding activity of 125I-labeled chylomicron remnant to reconstituted vesicles was unchanged. 45Ca blotting analysis showed the presence of 45Ca binding protein (approximately 600 kDa) in Hep G2 cells. The amount of 45Ca binding protein was not affected by cholesterol and was abolished by pronase treatment. These results suggest the existence of a functional receptor other than the LDL receptor that catabolizes chylomicron remnant in Hep G2 cells and that this receptor may correspond to LDL receptor-related protein.

Partial cloning of cDNA for hamster liver cholesterol 7 alpha-hydroxylase.

A partial cDNA clone encoding cholesterol 7 alpha-hydroxylase (pHA 7 alpha-3) was isolated from a hamster liver cDNA library using rat P-450 ch7 cDNA (p 7 alpha-11) as a probe. In comparison with the complete base sequence of p 7 alpha-11, pHA 7 alpha-3 lacked about 500 base pairs at the 5' end. Circadian rhythms of mRNA for hamster liver 3-hydroxy-3-methylglutaryl coenzyme A reductase and cholesterol 7 alpha-hydroxylase were investigated with cDNA clones encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (pRed-227) and pHA 7 alpha-3. Typical circadian rhythms of mRNA for both enzymes and a time lag between the two circadian rhythms were observed. The circadian rhythm of activity for each enzyme corresponded to that of each mRNA.

Effect of dietary hydrogenated corn oil (trans-octadecenoate rich oil) on plasma and hepatic cholesterol metabolism in the hamster.

The effect of dietary hydrogenated corn oil (trans-octadecenoate-rich oil) on plasma cholesterol and triglyceride concentrations was compared with dietary palmitic acid in hamsters given a cholesterol-rich diet. The addition of dietary palmitic acid and hydrogenated corn oil accelerated the increase in plasma VLDL- and LDL-cholesterol levels and plasma triglyceride level induced by dietary cholesterol loading. Dietary cholesterol, palmitic acid and hydrogenated corn oil showed no effect on plasma HDL-cholesterol concentration. A decrease in hepatic LDL receptor activity was seen in animals fed a diet supplemented with cholesterol in combination with palmitic acid or hydrogenated corn oil in comparison with animals fed a diet supplemented with cholesterol alone. Hydrogenated corn oil (trans-octadecenoate-rich oil) appears to potentiate the effect of dietary cholesterol in elevating the plasma VLDL- and LDL-cholesterol levels through the suppression of hepatic LDL receptor activity. trans-Octadecenoate in dietary hydrogenated corn oil may be as atherogenic as dietary palmitic acid due to a suppression of hepatic LDL receptors in the presence of dietary cholesterol loading.

Analysis of neutral amino acid transport systems in the small intestine: a study of brush border membrane vesicles.

Transport of L-proline, L-leucine and L-cysteine was studied in brush border membrane vesicles prepared from guinea pig ileum. Concentrative transport of L-proline, L-leucine and L-cysteine was obtained in the presence of an Na+ gradient from, outside to inside of the vesicles, which indicated contribution of either system A (alanine-preferring) or system ASC (alanine-, serine- and cysteine-preferring) to the transport. When Na+ was replaced by Li+, L-leucine and L-cysteine maintained the same concentrative transport. However, the concentrative transport of L-proline was markedly decreased by Li+ -for-Na+ substitution. Strong exchange properties of L-leucine transport via system L (leucine-preferring) was observed with brush border membrane vesicles, in which preloaded L-methionine could be exchanged with labeled L-leucine added outside the vesicles. These results suggest that the small intestine of the guinea pig possesses classical neutral amino acid transport systems such as systems A, ASC and L.

Metabolic changes in LDL receptors and an appearance of scavenger receptors after phorbol ester-induced differentiation of U937 cells.

Metabolic changes in lipoprotein receptors after cell differentiation were investigated using U937 cells, a human tumor cell line with monoblastic characteristics. After inducing the differentiation of U937 cells into monocyte-macrophage-like cells using TPA (12-tetradecanoyl-phorbol-13-acetate), the incorpotation of [14C]oleate into cellular cholesteryl [14C]oleate was increased in comparison with U937 cells when incubated with r-beta VLDL, h-VLDL or h-LDL. A marked down-regulation of LDL receptors was observed in U937 cells upon addition of 25-hydroxycholesterol. However, this down-regulation of LDL receptors was poor in monocyte-macrophage-like cells that had been induced to differentiate from U937 cells with TPA. Acyl coenzyme A:cholesterol acyltransferase activity was increased after TPA-induced differentiation of U-937 cells. The incorporation of [14C]oleate into cellular cholesteryl [14C]oleate was also increased when incubated with acetylated h-LDL in monocyte-macrophage-like cells in comparison with U937 cells. These results suggest that a poor down-regulation of LDL receptors, which is attributable to increased acyl coenzyme A:cholesterol acyltransferase activity, and scavenger receptors are induced and that these metabolic changes in lipoprotein receptors and an increased acyl coenzyme A:cholesterol acyltransferase activity contribute to cholesterol ester accumulation in monocyte-macrophage-like cells.

[The role of cholesterol and phosphatidylcholine on very low density lipoprotein secretion from rat hepatocytes].

The role of cholesterol and phosphatidylcholine on hepatic very low density lipoprotein secretion was investigated with rat hepatocytes. Hepatic very low density lipoprotein secretion (apo B, apo E, cholesterol, triglyceride, phosphatidylcholine) was decreased by the reduction of hepatic phosphatidylcholine content. However, cholesterol loading into hepatocytes did not affect hepatic very low density lipoprotein secretion. Hepatic apolipoprotein contents were constant and were not influenced by a change of hepatic cholesterol and phosphatidylcholine contents. These results suggest that lipids, which are constituents of lipoproteins, play different roles on hepatic very low density lipoprotein secretion.

Effects of dietary cholesterol and fatty acids on plasma cholesterol level and hepatic lipoprotein metabolism.

The effects of dietary cholesterol and fatty acids on the plasma cholesterol level and rates of very low density lipoprotein (VLDL) cholesterol secretion and low density lipoprotein (LDL) transport through LDL receptors in the liver of the hamster were investigated. Increases of plasma VLDL- and LDL-cholesterol levels and VLDL-cholesterol secretion from hepatocytes were observed in animals fed a diet enriched with 0.1% cholesterol for 2 weeks in comparison with animals fed a control diet. The addition of dietary palmitic acid accelerated the effect of dietary cholesterol on plasma VLDL- and LDL-cholesterol levels and VLDL-cholesterol secretion from hepatocytes. Dietary linoleic acid accelerated the effect of dietary cholesterol on VLDL-cholesterol secretion from hepatocytes and diminished the effect on the plasma LDL-cholesterol level. Hepatic LDL receptor activity was considerably suppressed by a control diet containing 0.05% cholesterol and a further small suppression was induced by a diet enriched with 0.1% cholesterol with or without 5% palmitic acid. However, dietary linoleic acid diminished the effect of dietary cholesterol on the suppression of hepatic LDL receptor activity. These results suggest that dietary palmitic acid augments the effect of dietary cholesterol in elevating the plasma LDL-cholesterol level through acceleration of VLDL-cholesterol secretion from the liver, and that dietary linoleic acid diminishes the effect of dietary cholesterol in elevating the plasma LDL-cholesterol level by preventing the suppression of hepatic LDL receptor activity induced by cholesterol.