Coexpression of constitutively active GSK-3beta[S9A] rescued the axonal pathology induced by overexpression of human tau in transgenic mice (Spittaels et al., (2000) J. Biol. Chem. 275, 41340-41349). We isolated dorsal root ganglion (DRG) neuronal cultures from adult tau4R- and tau4R x GSK-3beta-transgenic mice to define the mechanisms at the cellular and subcellular level. DRG from tau4R-trans...

Recently we demonstrated that IGF-1 expression is increased in the diabetic kidney and that it may involve in renal hypertrophy and extracellular matrix protein (ECM) accumulation in mesangial cells as seen in diabetic glomerulopathy. The present study investigates the molecular mechanism(s) of IGF-1 and Akt/glycogen synthase kinase-3beta (GSK-3beta) signaling pathway in the regulation of fibro...

Lithocholate (LC) (10-300 microM) in physiological solution is sensed by vascular myocyte large conductance, calcium- and voltage-gated potassium (BK) channel beta(1) accessory subunits, leading to channel activation and arterial dilation. However, the structural features in steroid and target that determine LC action are unknown. We tested LC and close analogs on BK channel (pore-forming cbv1+...

Phytochemical investigation of the ethanolic extract of defatted fruits of Malva sylvestris Linn. (Malvaceae) led to the isolation of six new steroidal lactones and a homomonoterpenic glucoside along with beta-sitosterol-3-beta-D-glucopyranoside. The structures of new phytoconstituents have been elucidated as cholest-5-en-3a-ol-18(21)-olide (sylvestrosterol A), cholest-9(11)-en-3alpha-ol-18(21)...

1. When [(14)C]cholesterol was incubated with rat liver mitochondria, radioactive 26-hydroxycholesterol, 3beta-hydroxychol-5-enoic acid and other bile acids were isolated from the incubation mixture. 2. In the absence of added 26-hydroxycholesterol, the specific radioactivity of the 26-hydroxycholesterol formed from [(14)C]cholesterol during the incubation was higher than that of the 3beta-hydr...

A phytochemical study of two plant species, Viscum cruciatum Sieber and Crataegus monogyna Jacq., was completed to investigate the influence of the parasite Viscum cruciatum on the host Crataegus monogyna. The study was carried out with two samples and consisted of hexane extracts of the Viscum cruciatum parasitizing on Crataegus monogyna and C monogyna. In these samples ursolic acid, beta-sito...

The dehydrogenation reaction of cholest-7-en-3beta-ol (I) to cholesta-5,7-dien-3beta-ol (II) in the presence of NADH was studied in rat liver microsomes and in microsomal acetone powder preparations, using [3alpha-3H]cholest-7-en-3beta-ol. It was found that the reaction was inhibited by menadione, adenosine diphosphate, potassium ferricyanide, and cytochrome c while p-cresol had no effect. Thes...

Increased airway smooth muscle (ASM) mass, a characteristic finding in asthma, may be caused by hyperplasia or hypertrophy. Cell growth requires increased translation of contractile apparatus mRNA, which is controlled, in part, by glycogen synthase kinase (GSK)-3beta, a constitutively active kinase that inhibits eukaryotic initiation factor-2 activity and binding of methionyl tRNA to the riboso...

hGSTA3-3 (human Alpha-class glutathione transferase 3-3) efficiently catalyses steroid Delta(5)-Delta(4) double-bond isomerization in vitro, using glutathione as a cofactor. This chemical transformation is an obligatory reaction in the biosynthesis of steroid hormones and follows the oxidation of 3beta-hydroxysteroids catalysed by 3beta-HSD (3beta-hydroxysteroid dehydrogenase). The isomerizatio...

Glycogen synthase kinase-3 (GSK-3) plays important roles in the regulation of glycogen and protein synthesis. In Alzheimer's disease it is responsible for hyperphosphorylation of tau. However, the role of GSK-3beta in brain aging and in neurodegenerative diseases is not fully elucidated. Our aim was to determine the protein level of GSK-3beta and its active, tyrosine 216-phosphorylated form in ...