Abstract Energy-producing pathways are novel therapeutic targets for the treatment of neurodevelopmental disorders. Here, we focussed on correcting metabolic defects in a catastrophic paediatric epilepsy, Dravet syndrome which is caused by mutations in sodium channel NaV1.1 gene, SCN1A. We utilized a translatable zebrafish model of Dravet syndrome (scn1lab) which exhibits key characteristics of patients with Dravet syndrome and shows metabolic deficits accompanied by down-regulation of gluconeogenesis genes, pck1 and pck2. Using a metabolism-based small library screen, we identified compounds that increased gluconeogenesis via up-regulation of pck1 gene expression in scn1lab larvae. Treatment with PK11195, a pck1 activator and a translocator protein ligand, normalized dys-regulated glucose levels, metabolic deficits, translocator protein expression and significantly decreased electrographic seizures in mutant larvae. Inhibition of pck1 in wild-type larvae mimicked metabolic and behaviour defects observed in scn1lab mutants. Together, this suggests that correcting dys-regulated metabolic pathways can be therapeutic in neurodevelopmental disorders such as Dravet syndrome arising from ion channel dysfunction.
Various natural agents, including grape seed extract (GSE), have shown considerable chemopreventive and anti-cancer efficacy against different cancers in pre-clinical studies; however, their specific protein targets are largely unknown and thus, their clinical usefulness is marred by limited scientific evidences about their direct cellular targets. Accordingly, herein, employing, for the first time, the recently developed drug affinity responsive target stability (DARTS) technique, we aimed to profile the potential protein targets of GSE in human colorectal cancer (CRC) cells. Unlike other methods, which can cause chemical alteration of the drug components to allow for detection, this approach relies on the fact that a drug bound protein may become less susceptible to proteolysis and hence the enriched proteins can be detected by Mass Spectroscopy methods. Our results, utilizing the DARTS technique followed by examination of the spectral output by LC/MS and the MASCOT data, revealed that GSE targets endoplasmic reticulum (ER) stress response proteins resulting in overall down regulation of proteins involved in translation and that GSE also causes oxidative protein modifications, specifically on methionine amino acids residues on its protein targets. Corroborating these findings, mechanistic studies revealed that GSE indeed caused ER stress and strongly inhibited PI3k-Akt–mTOR pathway for its biological effects in CRC cells. Furthermore, bioenergetics studies indicated that GSE also interferes with glycolysis and mitochondrial metabolism in CRC cells. Together, the present study identifying GSE molecular targets in CRC cells, combined with its efficacy in vast pre-clinical CRC models, further supports its usefulness for CRC prevention and treatment. Keywords: Chemoprevention, colorectal cancer, DARTS, grape seed extract.
Parkinson's disease (PD) is an age-related neurodegenerative disease in which the role of reactive oxygen species (ROS) is strongly implicated. The presence of oxidative stress has been detected in human and experimental PD using both direct and indirect indices. Scavenging ROS is, therefore, an important therapeutic avenue for the treatment of PD. Manganic porphyrins are catalytic antioxidants that scavenge a wide range of ROS. In this study, we tested the therapeutic effects of a compound [5,15-bis(methoxycarbonyl)-10,20-bis-trifluoromethyl-porphyrinato manganese (III) chloride (AEOL11207)] belonging to a new generation of lipophilic manganic porphyrins for neuroprotection and oral bioavailability in the mouse 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of parkinsonism. Groups of adult C57BL/6 mice were administered MPTP with varying subcutaneous or oral dosing regimens of AEOL11207. Neurotoxicity was assessed by measurement of striatal dopamine levels and quantification of tyrosine hydroxylase-positive neurons in the substantial nigra pars compacta one week after the first dose of MPTP. Glutathione depletion, lipid peroxidation, and 3-nitrotyrosine (3-NT) formation were measured as indicators of oxidative stress in the ventral midbrain in vivo . AEOL11207 administered either by subcutaneous or oral routes protected against MPTP-induced dopamine depletion in the striatum as well as dopaminergic neuronal loss, glutathione depletion, lipid peroxidation, and 3-NT formation in the ventral midbrain. Neuroprotection correlated with brain metalloporphyrin concentrations. This is the first demonstration of neuroprotection by an orally active catalytic antioxidant in the MPTP mouse model and suggests its potential clinical utility for the treatment of chronic neurodegenerative diseases such as PD.
The use of chemical warfare agents is an ongoing, significant threat to both civilians and military personnel worldwide. Nerve agents are by far the most formidable toxicants in terms of their lethality and toxicity. Nerve agents initiate neurotoxicity by the irreversible inhibition of acetylcholinesterase and resultant accumulation of acetylcholine in excitable tissues. The cholinergic toxidrome presents as miosis, lacrimation, diarrhea, fasciculations, seizures, respiratory arrest and coma. Current medical countermeasures can attenuate acute mortality and confer limited protection against secondary neuronal injury when given rapidly after exposure. However, there is an urgent need for the development of novel, add-on neuroprotective therapies to prevent mortality and long-term toxicity of nerve agents. Increasing evidence suggests that pathways other than direct acetylcholinesterase inhibition contribute to neurotoxicity and secondary neuronal injury. Among these, oxidative stress is emerging as a key therapeutic target for nerve agent toxicity. In this review, we discuss the rationale for targeting oxidative stress in nerve agent toxicity and highlight research investigating antioxidant therapy as a neuroprotective medical countermeasure to attenuate oxidative stress, neuroinflammation and neurodegeneration.
Background: Visual perception has hindered the development of blinded, placebo‐controlled ultraviolet light exposure conditions in humans. New acrylic thermoplastics that block or transmit ultraviolet light have visual properties that may provide a solution. Methods: In a series of triangle taste tests, 60 subjects were tested for the ability to visually perceive ultraviolet light transmission by two of four types of acrylic thermoplastics. Results: Forty‐six of sixty (67%) subjects were unable to visually detect ultraviolet light transmitting acrylics among ultraviolet blocking acrylics in both an ambient light background condition and an ambient light background condition with ultraviolet A light supplementation. Conclusion: Acrylic thermoplastics allow for the production of blinded, placebo‐controlled ultraviolet light exposure conditions by eliminating visual discrimination differences between active and control groups.