Development of NMDAR antagonists with reduced neurotoxic side effects: a study on GK11.

The NMDAR glutamate receptor subtype mediates various vital physiological neuronal functions. However, its excessive activation contributes to neuronal damage in a large variety of acute and chronic neurological disorders. NMDAR antagonists thus represent promising therapeutic tools that can counteract NMDARs' overactivation.

Challenges in the development of rodent models of mild traumatic brain injury.

Approximately 75% of traumatic brain injuries (TBI) are classified mild (mTBI). Despite the high frequency of mTBI, it is the least well studied. The prevalence of mTBI among service personnel returning from Operations Iraqi Freedom (OIF) and Enduring Freedom (OEF) and the recent reports of an association between repeated mTBI and the early onset of Alzheimer's and other types of dementias in retired athletes has focused much attention on mTBI.

Proteomic study of amyloid beta (25-35) peptide exposure to neuronal cells: Impact on APE1/Ref-1's protein-protein interaction.

The genotoxic, extracellular accumulation of amyloid β (Aβ) protein and subsequent neuronal cell death are associated with Alzheimer's disease (AD). APE1/Ref-1, the predominant apurinic/apyrimidinic (AP) endonuclease and essential in eukaryotic cells, plays a central role in the base excision repair (BER) pathway for repairing oxidized and alkylated bases and single-strand breaks (SSBs) in DNA. APE1/Ref-1 is also involved in the redox activation of several trans-acting factors (TFs) in various cell types, but little is known about its role in neuronal functions.

The role of eNOS, iNOS, and NF-kappaB in upregulation and activation of cyclooxygenase-2 and infarct size reduction by atorvastatin.

Pretreatment with atorvastatin (ATV) reduces infarct size (IS) and increases myocardial expression of phosphorylated endothelial nitric oxide synthase (p-eNOS), inducible NOS (iNOS), and cyclooxygenase-2 (COX2) in the rat. Inhibiting COX2 abolished the ATV-induced IS limitation without affecting p-eNOS and iNOS expression. We investigated 1) whether 3-day ATV pretreatment limits IS in eNOS(-/-) and iNOS(-/-) mice and 2) whether COX2 expression and/or activation by ATV is eNOS, iNOS, and/or NF-kappaB dependent.

Caffeinated coffee blunts the myocardial protective effects of statins against ischemia-reperfusion injury in the rat.

Purpose: We asked whether caffeinated coffee (CC) blunts the infarct size (IS)-limiting effects of atorvastatin (ATV).

Background: Adenosine receptor activation is essential for mediating the IS-limiting effects of statins. Caffeine is a nonspecific adenosine receptor blocker, and thus drinking CC may block the myocardial protective effects of statins.

The cardioprotective effect of a statin and cilostazol combination: relationship to Akt and endothelial nitric oxide synthase activation.

Background: Atorvastatin (ATV) protects against ischemia-reperfusion by upregulating Akt and subsequently, endothelial nitric oxide synthase (eNOS) phosphorylation at Ser-1177. However, when given orally, high doses of ATV (10 mg/kg/d) are needed to achieve maximal protective effect in the rat. Protein kinase A (PKA) also phosphorylates eNOS at Ser-1177.

The central role of adenosine in statin-induced ERK1/2, Akt, and eNOS phosphorylation.

Statins activate phosphatidylinositol-3-kinase, which activates ecto-5'-nucleotidase and phosphorylates 3-phosphoinositide-dependent kinase-1 (PDK-1). Phosphorylated (P-)PDK-1 phosphorylates Akt, which phosphorylates endothelial nitric oxide synthase (eNOS). We asked if the blockade of adenosine receptors (A(1), A(2A), A(2B), or A(3) receptors) could attenuate the induction of Akt and eNOS by atorvastatin (ATV) and whether ERK1/2 is involved in the ATV regulation of Akt and eNOS.

Enhanced cardioprotection against ischemia-reperfusion injury with a dipyridamole and low-dose atorvastatin combination.

Atorvastatin (ATV) limits infarct size (IS) by activating Akt and ecto-5-nucleotidase, which generates adenosine. Activated Akt and adenosine activate endothelial nitric oxide synthase (eNOS). When given orally, high doses (10 mg/kg) are needed to achieve full protection.

Immunohistochemical staining of transgenic beta-galactosidase in burned skin is a better indicator of transfection efficiency than histochemical techniques.

The non-mammalian reporter gene LacZ, encoding the protein beta-galactosidase (beta-Gal), has long been used to test the efficiency of gene transfer into cells in culture or tissues in vivo. Biodistribution and dose-response transfection experiments rely upon a sensitive and specific technique for accurate results. We conducted an experiment to compare two techniques of identifying beta-galactosidase expression.

The transcription factor Yin Yang 1 is an activator of BACE1 expression.

The beta-site amyloid precursor protein-cleaving enzyme 1 (BACE1) is a prerequisite for the generation of beta-amyloid peptides, the principle constituents of senile plaques in the brains of patients with Alzheimer's disease (AD). BACE1 expression and enzymatic activity are increased in the AD brain, but the regulatory mechanisms of BACE1 expression are largely unknown. Here we show that Yin Yang 1 (YY1), a highly conserved and multifunctional transcription factor, binds to its putative recognition sequence within the BACE1 promoter and stimulates BACE1 promoter activity in rat pheochromocytoma 12 (PC12) cells, rat primary neurones and astrocytes.

Delayed cell death signaling in traumatized central nervous system: hypoxia.

There are two different ways for cells to die: necrosis and apoptosis. Cell death has traditionally been described as necrotic or apoptotic based on morphological criteria. There are controversy about the respective roles of apoptosis and necrosis in cell death resulting from trauma to the central nervous system (CNS).

One path to cell death in the nervous system.

Both acute and chronic insults to the nervous system can result in changes in homeostasis that result in cell death or recovery processes that alter function. The signaling mechanisms for this broad spectrum of events that impair neurological function span the gamut from abrupt injury to the slow onset of neurodegenerative diseases in extreme aging. A common element in all of these events is the triggering of signal cascades that determine cellular commitment to apoptosis as a ameliorative alternative to inflammatory necrosis.

Insulin-like growth factor-I cDNA gene transfer in vitro and in vivo.

Our hypothesis is that gene transfer of an IGF-I CMV-cDNA with cholesterol containing cationic liposomes is an efficient tool for transient transfection of growth factors in vitro and in vivo. In vitro, we transiently cotransfected IGF-I cDNA with a CMV construct and a Lac Z beta-galactosidase cDNA/CMV construct using cholesterol containing cationic liposomes and measured beta-galactosidase and IGF-I mRNA and protein. In vivo, we subcutaneously injected 3-month-old male Sprague-Dawley rats with IGF-I cDNA and beta-galactosidase cDNA into rat skin.

NGF levels decrease in the spinal cord and dorsal root ganglion after spinal hemisection.

To examine changes in nerve growth factor (NGF) levels in spinal cord and dorsal root ganglia (DRG) after spinal injury, male Sprague-Dawley rats weighing 150-175 g were given spinal hemisections. NGF content was measured at various post-surgical times and compared with naive controls (n = 4 per time point) in the spinal cord, DRG and blood serum by ELISA techniques (Promega). Levels of NGF in the blood serum were significantly increased 8-fold at 48h but were significantly decreased in the spinal cord and DRG by 2- to 4-fold until 7 days postsurgery (ANOVA, p < 0.

Brain-derived neurotrophic factor (BDNF) protects cultured rat cerebellar granule neurons against glucose deprivation-induced apoptosis.

In the present study, cell death induced by glucose deprivation in primary cultures of cerebellar granule neurons was examined. Glucose deprivation-induced apoptotic cell death was demonstrated using the terminal transferase-mediated (TdT) deoxyuridine triphosphate (d-UTP)-biotin nick end labeling (TUNEL) method and DNA fragmentation assays. When the effects of different neurotrophins on the survival of cerebellar granule neurons after glucose deprivation were assessed, BDNF, but not NT-3 or NGF, was found to protect cerebellar granule neurons against glucose deprivation-induced cell death.

Oxidative defense enzyme activity and mRNA levels in lenses of diabetic rats.

This study examines the mRNA expression and enzyme activity of oxidative defense enzymes during the course of streptozotocin-induced hyperglycemic cataract development. Diabetes was produced in 5-wk-old male Sprague-Dawley rats by administering streptozotocin ip and mRNA expression and enzyme activity were monitored on d 4, 8, 12, 16, 20, 40, 60, and 80; concomitantly, the onset and progress of cataract was followed by digital image analysis. Peak enzyme activity and mRNA expression were attained between d 20 and 40.

Regulation of antioxidant enzyme expression by NGF.

The rapid decreases in viability seen in H2O2-treated PC12 cells reflect enhanced susceptibility of neural cell types to oxidant injury. The dose-response relationship between NGF concentration and survival after H2O2 treatment resembles that for NGF effects on PC12 survival in serumless medium. Previously we have shown that NGF treatment enhances the activity of GSH-Px and catalase which catalyze the degradation of H2O2.

Increased uptake of L-cysteine and L-cystine by nerve growth factor in rat pheochromocytoma cells.

Nerve growth factor is a neurotrophic factor which promotes cell survival and differentiation in the central and peripheral nervous system. The rat pheochromocytoma (PC12) cell has been frequently used to study the actions of nerve growth factor (NGF). Our previous studies demonstrate that pretreatment with NGF for 24 h protects PC12 cells from oxidative stress by increasing glutathione (GSH) concentrations and the activity of gamma-glutamylcysteine synthetase, which is a rate-limiting enzyme in GSH synthesis.

Regulation of gamma-glutamylcysteine synthetase activity by nerve growth factor.

Nerve growth factor is a neurotrophic factor that regulates neuronal cell development, maintenance, and injury responses in the peripheral and central nervous system. Nerve growth factor reduces injury owing to oxidative stress in rat pheochromocytoma (PC12) cells by increasing intracellular glutathione, in part owing to its stimulation of the activity of gamma-glutamylcysteine synthetase, which is the rate-limiting enzyme in the synthesis of glutathione. Here we show that nerve growth factor did not increase the activity of gamma-glutamylcysteine synthetase in PC12 cells at the transcriptional level.

Altered NGF protein levels in different brain areas after immunolesion.

Nerve growth factor (NGF) provides critical trophic support to the cholinergic basal forebrain neurons that express high levels of the low-affinity NGF receptor (p75NGFR) in the adult rat brain. Intraventricular injection of 192 IgG-saporin, made by coupling the monoclonal antibody to p75NGFR 192 IgG to the cytotoxin saporin, selectively destroys the p75NGFR-bearing neurons in the basal forebrain and was used here to examine the effects of selective cholinergic lesions on brain NGF protein levels. We showed that 192 IgG-saporin produced significant long-lasting elevation of NGF protein levels in the hippocampus, cortex, and olfactory bulb, with profound reductions of ChAT activities representing complete cholinergic deafferentations of these areas.

Regional CNS uptake of blood-borne nerve growth factor.

Nerve growth factor (NGF), in addition to being a neurotrophic substance, has effects on the endocrine and immune systems. For example, intravenous injection of NGF results in a cascade of events leading to an increase in glucocorticoid secretion. While this response appears to be mediated centrally, there has been no evidence that circulating NGF has access to the CNS.

Role of nerve growth factor in oxidant homeostasis: glutathione metabolism.

Free radicals are generated in the CNS by ongoing oxygen metabolism and biological events associated with injury and inflammation. Increased free radical levels may also persist in some chronic neurological diseases and in the aged. Nerve growth factor (NGF) is a member of the neurotrophin family of proteins that can regulate neuronal development, maintenance, and recovery from injury.