Purpose. The present study investigated the potential effects of long-term T3 treatment on glioma tumor cell lines. Thyroid hormone action on cell growth, differentiation and survival during development may be of therapeutic relevance Methods and Results 1321N1 cell line, an astrocytoma grade II, and U87MG, a glioblastoma grade IV, were exposed for 2 and 4 days in medium deprived of T3 and in m...

1 Transient accumulation of extracellular ATP reflects both release of ATP from intracellular stores and altered rates of ATP metabolism by ecto-enzymes. Ecto-nucleoside triphosphate diphosphohydrolases (eNTPDases) and ecto-nucleotide pyrophosphatases (eNPPs) degrade ATP, while ecto-nucleotide diphosphokinases (eNDPKs) synthesize ATP from ambient ADP. 2 Although the methylene ATP analogs betaga...

Dysfunction of D-amino acid oxidase (DAO) and DAO activator (DAOA)/G72 genes have been linked to neuropsychiatric disorders. The glutamate hypothesis of schizophrenia has proposed that increased DAO activity leads to decreased D-serine, which subsequently may lead to N-methyl-D-aspartate (NMDA) receptor hypofunction. It has been shown that DAOA binds to DAO and increases its activity. However, ...

Phenylketonuria is a genetic defect that, without strict dietary control, results in the accumulation of phenylalanine (Phe) in body fluids. If a low-Phe diet is not maintained during pregnancy, the offspring of phenylketonuric women are born with mental retardation and microcephaly. Primary cultures of rat cerebellar granule cells, rat cortical astrocytes, human fetal astrocytes, and human neu...

Recent evidence supporting a role for phosphoinositides in the endocytosis of phospholipase C-coupled receptors has prompted an investigation of whether there exists a similar requirement for the internalization of adenylyl cyclase-linked receptors. When 1321N1 astrocytoma cells, which possess both muscarinic cholinergic receptors (mAChRs) that couple to phospholipase C and beta-adrenergic rece...

We previously reported that ATP release from 1321N1 human astrocytoma cells could be stimulated either by activation of G protein-coupled receptors (GPCR) or by hypotonic stress. Cheema et al. (Cheema TA, Ward CE, Fisher SK. J Pharmacol Exp Ther 315: 755-763, 2005) have demonstrated that thrombin activation of protease-activated receptor 1 (PAR1) in 1321N1 cells and primary astrocytes acts syne...

Over time, mounting evidence has demonstrated extra-gastric manifestations of Helicobacter pylori infection. As such, a number studies the potential contribution H. infection to incidence and progression Alzheimer's disease (AD). Considering unanswered questions regarding effect on brain activity, we sought investigate impact expression AD-associated risk factors. We used two clinical strains o...

The relative capacities of muscarinic cholinergic receptor (MR) and bradykinin (BK)-receptor activation to increase phosphoinositide hydrolysis and to increase cytosolic Ca2+ were compared in NG108-15 neuroblastoma x glioma and 1321N1 human astrocytoma cells. In 1321N1 cells, the muscarinic cholinergic agonist carbachol and BK each stimulated a concentration-dependent accumulation of inositol p...

Thrombin and insulin receptor signaling via phosphoinositide (PI)-specific phospholipase C (PLC) and PI 3-kinase was studied in [3H]inositol-labelled 1321N1 cells. Thrombin stimulated a dramatic, transient activation of PLC which is probably mediated via receptors of the 'tethered-ligand' type, since it was both reproduced by, and abolished following, pretreatment of cells with a synthetic pept...

Glial cells release neurotrophic factors that maintain neurons functionally. Previously, we have shown that the scabronines isolated from Sarcodon scabrosus enhanced the secretion of neurotrophic factors from 1321N1 human astrocytoma cells. In the present study, we examined the mechanism of newly synthesized scabronine G-methylester (ME)-induced secretion of neurotrophic factors from 1321N1 cel...