Background: Fibroblast growth factor 21, a novel regulator of glucose and lipid metabolism, has robust protective properties in neurons. However, its expression and function in glia are unknown. Valproic acid, a mood stabilizer and anticonvulsant, is a histone deacetylase inhibitor and a dynamic gene regulator.
View Article and Find Full Text PDFHistone deacetylase (HDAC) 6 exists exclusively in cytoplasm and deacetylates cytoplasmic proteins such as α-tubulin. HDAC6 dysfunction is associated with several pathological conditions in the central nervous system. This study investigated the beneficial effects of tubastatin A (TubA), a novel specific HDAC6 inhibitor, in a rat model of transient middle cerebral artery occlusion (MCAO) and an in vitro model of excitotoxicity.
View Article and Find Full Text PDFAstrocyte elevated gene-1 (AEG-1) has been reported to regulate the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and is also regulated by it. This study investigated how AEG-1 participates in the survival pathway of motor neurons in amyotrophic lateral sclerosis (ALS). We found reduced levels of AEG-1 in ALS motor neurons, both in vivo and in vitro, compared to wild type controls.
View Article and Find Full Text PDFTraumatic brain injury (TBI) is a leading cause of disability and death from trauma to central nervous system (CNS) tissues. For patients who survive the initial injury, TBI can lead to neurodegeneration as well as cognitive and motor deficits, and is even a risk factor for the future development of neurodegenerative disorders such as Alzheimer's disease. Preclinical studies of multiple neuropathological and neurodegenerative disorders have shown that lithium, which is primarily used to treat bipolar disorder, has considerable neuroprotective effects.
View Article and Find Full Text PDFFibroblast growth factor-21 (FGF-21) is a new member of the FGF super-family and an important endogenous regulator of glucose and lipid metabolism. It has been proposed as a therapeutic target for diabetes and obesity. Its function in the central nervous system (CNS) remains unknown.
View Article and Find Full Text PDFObject: Although traumatic brain injury (TBI) is the leading cause of death and morbidity in young adults, no effective pharmaceutical treatment is available. By inhibiting glycogen synthase kinase-3 (GSK-3) and histone deacetylases (HDACs), respectively, lithium and valproate (VPA) have beneficial effects in diverse neurodegenerative diseases. Furthermore, in an excitotoxic neuronal model and in animal models of amyotrophic lateral sclerosis, Huntington disease, and stroke, combined treatment with lithium and VPA produces more robust neuroprotective effects than treatment with either agent alone.
View Article and Find Full Text PDFBackground And Purpose: Enhanced angiogenesis facilitates neurovascular remodeling processes and promotes brain functional recovery after stroke. Previous studies from our laboratory demonstrated that valproate (VPA), a histone deacetylase inhibitor, protects against experimental brain ischemia. The present study investigated whether VPA could enhance angiogenesis and promote long-term functional recovery after ischemic stroke.
View Article and Find Full Text PDFBackground And Purpose: The migratory efficiency of mesenchymal stem cells (MSC) toward cerebral infarct after transplantation is limited. Valproate (VPA) and lithium enhance in vitro migration of MSC by upregulating CXC chemokine receptor 4 and matrix metalloproteinase-9, respectively. Ability of VPA and lithium to promote MSC homing and to improve functional recovery was assessed in a rat model of cerebral ischemia.
View Article and Find Full Text PDFEmerging evidence suggests that the mood stabilizers lithium and valproate (VPA) have broad neuroprotective and neurotrophic properties, and that these occur via inhibition of glycogen synthase kinase 3 (GSK-3) and histone deacetylases (HDACs), respectively. Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by impaired movement, cognitive and psychiatric disturbances, and premature death. We treated N171-82Q and YAC128 mice, two mouse models of HD varying in genetic backgrounds and pathological progressions, with a diet containing therapeutic doses of lithium, VPA, or both.
View Article and Find Full Text PDFValproic acid (VPA), a histone deacetylase (HDAC) inhibitor, is known to protect against cerebral ischemia. The effects of VPA on blood-brain barrier (BBB) disruption were investigated in rats subjected to transient middle cerebral artery occlusion (MCAO). Postischemic VPA treatment remarkably attenuated MCAO-induced BBB disruption and brain edema.
View Article and Find Full Text PDFThe mood-stabilizing and anticonvulsant drug valproic acid (VPA) inhibits histone deacetylases (HDACs). The aim of the present study was to determine the effect of HDAC inhibition on overall and target gene promoter-associated histone methylation in rat cortical neurons and astrocytes. We found that VPA and other HDAC inhibitors, including sodium butyrate (SB), trichostatin A (TSA), and the Class I HDAC inhibitors MS-275 and apicidin all increased levels of histone 3 lysine 4 dimethylation and trimethylation (H3K4Me2 and H3K4Me3); these processes are linked to transcriptional activation in rat cortical neurons and astrocytes.
View Article and Find Full Text PDFMesenchymal stem cells (MSCs) show high potential for the therapy of several human diseases; however, the effectiveness of MSC transplantation has been hampered by the relatively poor migratory capacity of these cells toward disease target sites. This study investigated whether treatment of MSCs with two mood stabilizers-valproic acid (VPA) and lithium-would enhance cell migration and, if so, to explore the mechanisms underlying their effects. Short-term (3 h) exposure of MSCs to a relatively high concentration (2.
View Article and Find Full Text PDFInhibition of glycogen synthase kinase-3 (GSK-3) by pharmacological tools can produce antidepressant-like effects in rodents. However, the GSK-3 isoform(s) and brain region(s) involved in regulating these behavioural effects remain elusive. We studied the effects of bilateral intra-hippocampal injections of lentivirus-expressing short-hairpin (sh)RNA targeting GSK-3β on behavioural performance in mice subjected to chronic stress.
View Article and Find Full Text PDFNeuroprotective properties of the mood stabilizer valproic acid (VPA) are implicated in its therapeutic efficacy. Heat-shock protein 70 (HSP70) is a molecular chaperone, neuroprotective and anti-inflammatory agent. This study aimed to investigate underlying mechanisms and functional significance of HSP70 induction by VPA in rat cortical neurons.
View Article and Find Full Text PDFIn the healthy adult brain, neurogenesis normally occurs in the subventricular zone (SVZ) and hippocampal dentate gyrus (DG). Cerebral ischemia enhances neurogenesis in neurogenic and non-neurogenic regions of the ischemic brain of adult rodents. This study demonstrated that post-insult treatment with a histone deacetylase inhibitor, sodium butyrate (SB), stimulated the incorporation of bromo-2'-deoxyuridine (BrdU) in the SVZ, DG, striatum, and frontal cortex in the ischemic brain of rats subjected to permanent cerebral ischemia.
View Article and Find Full Text PDFLithium and valproic acid (VPA) are two primary drugs used to treat bipolar mood disorder and have frequently been used in combination to treat bipolar patients resistant to monotherapy with either drug. Lithium, a glycogen synthase kinase-3 (GSK-3) inhibitor, and VPA, a histone deacetylase (HDAC) inhibitor, have neuroprotective effects. The present study was undertaken to demonstrate synergistic neuroprotective effects when both drugs were coadministered.
View Article and Find Full Text PDFWe investigated the cytoprotective effects of lithium, the mood-stabilizer, on thapsigargin-induced stress on the endoplasmic reticulum (ER) in rat PC12 cells. Protracted lithium pretreatment of PC12 cells elicited cytoprotection against thapsigargin-induced cytotoxicity. Lithium protection was concurrent with inhibition of thapsigargin-induced intracellular calcium increase and with elevated expression of the molecular chaperone GRP78.
View Article and Find Full Text PDFNeurotrophin-induced neuroprotection against apoptosis was investigated using immature cultured cerebellar granule cells (CGC) from newborn rat pups. Apoptotic cell death induced by treatment with cytosine arabinoside (AraC) was confirmed by DNA fragmentation and quantified by cell survival assays. AraC was most effective in inducing apoptosis when added to CGC on the day of culture preparation, while less or no effect was observed when added at 24 or 48h after plating, respectively.
View Article and Find Full Text PDFValproic acid (VPA), used to treat bipolar mood disorder and seizures, also inhibits histone deacetylase (HDAC). Here, we found that VPA and other HDAC inhibitors, butyrate and trichostatin A, robustly protected mature cerebellar granule cell cultures from excitotoxicity induced by SYM 2081 ((2S, 4R)-4-methylglutamate), an inhibitor of excitatory amino-acid transporters and an agonist of low-affinity kainate receptors. These neuroprotective effects required protracted treatment and were correlated with enhanced acetylated histone levels, indicating HDAC inhibition.
View Article and Find Full Text PDFGrowing evidence from in vitro studies supports that valproic acid (VPA), an anti-convulsant and mood-stabilizing drug, has neuroprotective effects. The present study investigated whether VPA reduces brain damage and improves functional outcome in a transient focal cerebral ischemia model of rats. Subcutaneous injection of VPA (300 mg/kg) immediately after ischemia followed by repeated injections every 12 h, was found to markedly decrease infarct size and reduce ischemia-induced neurological deficit scores measured at 24 and 48 h after ischemic onset.
View Article and Find Full Text PDFLithium has long been one of the primary drugs used to treat bipolar mood disorder. However, neither the etiology of this disease nor the therapeutic mechanism(s) of this drug is well understood. Several lines of clinical evidence suggest that lithium has neurotrophic actions.
View Article and Find Full Text PDFCurr Opin Genet Dev
April 2003
In eukaryotes, mRNAs are monitored for errors in gene expression by RNA surveillance where untranslatable mRNAs are selectively degraded by the nonsense-mediated mRNA decay (NMD) pathway. Depending on the organism, three to seven genes are required for NMD. Besides RNA surveillance, the genes required for NMD serve a second purpose by controlling the overall abundance of a substantial fraction of the transcriptome.
View Article and Find Full Text PDFThe number of neurons in the brain is controlled by production of new neurons and neuronal death. Neural progenitor proliferation in the developing and adult brain plays a prominent role in the production of new neurons. Here, we examined the effects of lithium, a mood-stabilizing drug, on neuronal proliferation in rat primary neuronal cultures.
View Article and Find Full Text PDFIn rat cerebellar granule cells, glutamate induced rapid activation of c-Jun N-terminal kinase (JNK) and p38 kinase to phosphorylate c-Jun (at Ser63) and p53 (at Ser15), respectively, and a subsequent marked increase in activator protein-1 (AP-1) binding that preceded apoptotic death. These glutamate-induced effects and apoptosis could largely be prevented by long-term (7 days) pretreatment with 0.5-2 mm lithium, an antibipolar drug.
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