Search results for "Neurotoxins"

Toxic Tau Oligomers Modulated by Novel Curcumin Derivatives

2019

AbstractThe pathological aggregation and accumulation of tau, a microtubule-associated protein, is a common feature amongst more than 18 different neurodegenerative diseases that are collectively known as tauopathies. Recently, it has been demonstrated that the soluble and hydrophobic tau oligomers are highly toxic in vitro due to their capacity towards seeding tau misfolding, thereby propagating the tau pathology seen across different neurodegenerative diseases. Modulating the aggregation state of tau oligomers through the use of small molecules could be a useful therapeutic strategy to target their toxicity, regardless of other factors involved in their formation. In this study, we screen…

Dopamine, Noradrenaline and Serotonin Receptor Densities in the Striatum of Hemiparkinsonian Rats following Botulinum Neurotoxin-A Injection.

2017

Abstract Parkinson’s disease (PD) is characterized by a degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) that causes a dopamine (DA) deficit in the caudate-putamen (CPu) accompanied by compensatory changes in other neurotransmitter systems. These changes result in severe motor and non-motor symptoms. To disclose the role of various receptor binding sites for DA, noradrenaline, and serotonin in the hemiparkinsonian (hemi-PD) rat model induced by unilateral 6-hydroxydopamine (6-OHDA) injection, the densities of D1, D2/D3, α1, α2, and 5HT2A receptors were longitudinally visualized and measured in the CPu of hemi-PD rats by quantitative in vitro receptor autorad…

The Anemonia viridis Venom: Coupling Biochemical Purification and RNA-Seq for Translational Research

2018

Blue biotechnologies implement marine bio-resources for addressing practical concerns. The isolation of biologically active molecules from marine animals is one of the main ways this field develops. Strikingly, cnidaria are considered as sustainable resources for this purpose, as they possess unique cells for attack and protection, producing an articulated cocktail of bioactive substances. The Mediterranean sea anemone Anemonia viridis has been studied extensively for years. In this short review, we summarize advances in bioprospecting of the A. viridis toxin arsenal. A. viridis RNA datasets and toxin data mining approaches are briefly described. Analysis reveals the major pool of neurotoxi…

Triclosan-Evoked Neurotoxicity Involves NMDAR Subunits with the Specific Role of GluN2A in Caspase-3-Dependent Apoptosis

2018

Triclosan (TCS) is an antimicrobial agent that is used extensively in personal care and in sanitising products. A number of studies have shown the presence of TCS in different human tissues such as blood, adipose tissue, the liver, brain as well as in breast milk and urine. N-Methyl-D-aspartate receptors (NMDARs) are glutamate-gated ion channels that are widely expressed in the central nervous system and which play key roles in excitatory synaptic transmission. There is, however, no data on the involvement of NMDAR subunits in the apoptotic and neurotoxic effects of TCS. Our experiments are the first to show that TCS used at environmentally relevant concentrations evoked NMDA-dependent effe…

Preoperative Botulinum Toxin and Progressive Pneumoperitoneum Are Useful in the Treatment of Large Incisional Hernias.

2019

Treatment of masseteric hypertrophy with botulinum toxin: A report of two cases

2010

BAS, BURCU/0000-0003-0593-3400; Kutuk, Nukhet/0000-0001-6563-1899 WOS: 000279667400021 PubMed: 20173718 Masseter muscle hypertrophy is a rare condition of unknown cause which is important in the differential diagnosis of head and neck masses, located in the cheek. Several treatment options reported for masseter hypertrophy, which range from simple pharmacotherapy to more invasive surgical reduction. Botulinum toxin type A is a powerful neurotoxin which is produced by the anaerobic organism Clostridium botulinum and when injected into a muscle causes interference with the neurotransmitter mechanism producing selective paralysis and subsequent atrophy of the muscle. Injection of botulinum tox…

Impaired calcium homeostasis in aged hippocampal neurons

2009

Abstract Development of neurodegenerative diseases such as Alzheimer's and Parkinson's disease is strongly age-associated. The impairment of calcium homeostasis is considered to be a key pathological event leading to neuronal dysfunction and cell death. However, the exact impact of aging on calcium homeostasis in neurons remains largely unknown. In the present work we have investigated intracellular calcium levels in cultured primary hippocampal neurons from young (2 months) and aged (24 months) rat brains. Upon stimulation with glutamate or hydrogen peroxide aged neurons in comparison to young neurons demonstrated an increased vulnerability to these disease-related toxins. Measurement of c…

Exposure to gp120 of HIV-1 induces an increased release of arachidonic acid in rat primary neuronal cell culture followed by NMDA receptor-mediated n…

1995

After incubation of highly enriched neurons from rat cerebral cortex with the HIV-1 coat protein gp120 for 18 h, cells showed fragmentation of DNA at internucleosomal linkers followed by NMDA receptor-mediated neurotoxicity. We report that in response to exposure to gp120 cells react with an increased release of arachidonic acid (AA) via activation of phospholipase A2. This process was not inhibited by NMDA receptor antagonists. To investigate the role of AA on the sensitivity of the NMDA receptor towards its agonist, low concentrations of NMDA were co-administered with AA. This condition enhanced the NMDA-mediated cytotoxicity. Administration of mepacrine reduced cytotoxicity caused by gp1…

Novel imine antioxidants at low nanomolar concentrations protect dopaminergic cells from oxidative neurotoxicity.

2009

Strong evidence indicates that oxidative stress may be causally involved in the pathogenesis of Parkinson's disease. We have employed human dopaminergic neuroblastoma cells and rat primary mesencephalic neurons to assess the protective potential of three novel bisarylimine antioxidants on dopaminergic cell death induced by complex I inhibition or glutathione depletion. We have found that exceptionally low concentrations (EC(50) values approximately 20 nM) of these compounds (iminostilbene, phenothiazine, and phenoxazine) exhibited strong protective effects against the toxicities of MPP(+), rotenone, and l-buthionine sulfoximine. Investigating intracellular glutathione levels, it was found t…

Aß(25-35) and its C-and/or N-blocked derivatives: copper driven structural features and neurotoxicity

2006

The toxic properties of beta-amyloid protein, Abeta(1-42), the major component of senile plaques in Alzheimer's disease, depend on nucleation-dependent oligomerization and aggregation. In addition, Abeta(1-42) toxicity is favored by the presence of trace metals, which affect the secondary structure of the peptide. A peptide comprising 11 residues within Abeta(1-42) [Abeta(25-35)] aggregates and retains the neurotoxic activity of Abeta(1-42). We have used both Abeta(25-35) and its C-amidated or N-acetylated/C-amidated derivatives to investigate the role of copper(II) in modulating the conformation and aggregation state as well as the neurotoxic properties of amyloid peptides. Electrospray io…