Neuroprotective Effect of the Novel Compound ITH33/IQM9.21 Against Oxidative Stress and Na+ and Ca2+ Overload in Motor Neuron-like NSC-34 Cells

Cytotoxicity Models in Chromaffin Cells to Evaluate Neuroprotective Compounds

Primary cultures of bovine chromaffin cells are considered a good model to evaluate potential neuroprotective compounds for two major reasons: (i) they share many common features to neurons as they synthesize, store, and release neurotransmitters; they are excitable cells that express voltage-dependent calcium, potassium, and sodium channels; they express different neuronal receptor subtypes; and (ii) they can be easily cultured in high quantities from adult animals; as adult para-neurons, they can be used to reproduce different neurodegenerative-like cytotoxicity models. In this chapter, we describe protocols to mimic calcium overload (veratridine and thapsigargin) and oxidative stress (rotenone plus oligomycin-A and 6-hydroxydopamine) to evaluate potential neuroprotective compounds.

Resveratrol: A potential therapeutic natural polyphenol for neurodegenerative diseases associated with mitochondrial dysfunction

Most polyphenols can cross blood-brain barrier, therefore, they are widely utilized in the treatment of various neurodegenerative diseases (ND). Resveratrol, a natural polyphenol contained in blueberry, grapes, mulberry, etc., is well documented to exhibit potent neuroprotective activity against different ND by mitochondria modulation approach. Mitochondrial function impairment is the most common etiology and pathological process in various neurodegenerative disorders, viz. Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and amyotrophic lateral sclerosis. Nowadays these ND associated with mitochondrial dysfunction have become a major threat to public health as well as health care systems in terms of financial burden. Currently available therapies for ND are limited to symptomatic cures and have inevitable toxic effects. Therefore, there is a strict requirement for a safe and highly effective drug treatment developed from natural compounds. The current review provides updated information about the potential of resveratrol to target mitochondria in the treatment of ND.

Neuroprotection by urate on the mutant hSOD1-related cellular and Drosophila models of amyotrophic lateral sclerosis: Implication for GSH synthesis via activating Akt/GSK3β/Nrf2/GCLC pathways

Oxidative stress has been considered as a principal mechanism of motor neuron death in amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease which could be caused by dominant mutations in an antioxidant enzyme superoxide dismutase-1 (SOD1). The aim of the present study was to investigate the potential neuroprotective effects and mechanisms of urate, an important endogenous antioxidant and a biomarker of favorable ALS progression rates, in the mutant human SOD1-related cellular and Drosophila models of ALS. Our results showed that urate treatment provided neuroprotective effects as confirmed by enhanced survival, attenuated motor impairments, reduced oxidative damage and increased antioxidant defense in hSOD1-G85R-expressing Drosophila models of ALS. In vitro studies, we demonstrated that urate protected motor neurons (NSC-34 cells) against hSOD1-G93A-induced cell damage and apoptosis by decreasing reactive oxygen specials (ROS) production and oxidative damage. Moreover, urate markedly increased the expression and activation of nuclear factor erythroid 2-related factor 2 (Nrf2), stimulated Nrf2-targeted antioxidant gene glutathione cysteine ligase catalytic subunit (GCLC) expression and glutathione (GSH) synthesis by upregulating Akt/GSK3β pathway. Furthermore, the inhibition of Akt pathway with LY294002 abolished urate-mediated elevation of GSH synthesis and neuroprotective effects both in vivo and in vitro. Overall, these results suggested that, in addition to its direct scavenging of ROS, urate markedly enhanced GSH expression by activating Akt/GSK3β/Nrf2/GCLC pathway, and thus offering neuroprotective effects on motor neurons against oxidative stress.

Profiling donepezil template into multipotent hybrids with antioxidant properties

Alzheimer’s disease is debilitating neurodegenerative disorder in the elderly. Current therapy relies on administration of acetylcholinesterase inhibitors (AChEIs) -donepezil, rivastigmine, galantamine, and N-methyl-d-aspartate receptor antagonist memantine. However, their therapeutic effect is only short-term and stabilizes cognitive functions for up to 2 years. Given this drawback together with other pathological hallmarks of the disease taken into consideration, novel approaches have recently emerged to better cope with AD onset or its progression. One such strategy implies broadening the biological profile of AChEIs into so-called multi-target directed ligands (MTDLs). In this review article, we made comprehensive literature survey emphasising on donepezil template which was structurally converted into plethora of MTLDs preserving anti-cholinesterase effect and, at the same time, escalating the anti-oxidant potential, which was reported as a crucial role in the pathogenesis of the Alzheimer’s disease.

Midazolam prevents motor neuronal death from oxidative stress attack mediated by JNK-ERK pathway

Midazolam is a sedative used by patients with mechanical ventilation. However, the potential clinical value is not fully explored. In this report, we made use of a neuroblastoma-spinal cord hybrid motor neuron-like cell line NSC34, and elucidated the potential role of Midazolam on these cells under the insult of oxidative stress. We found the protective effect of Midazolam on motor neurons against cytotoxicity induced by the combination of oligomycin A and rotenone (O/R) or phenylarsine oxide. The characteristics of apoptosis, such as the ratio of TUNEL+ cells or the expression level of cleaved Caspase-3, was decreased by 22 or 45% in the presence of Midazolam. Furthermore, this effect was correlated with the JNK-ERK signaling pathway. Either phosphorylation of ERK or JNK was positively or negatively modulated with the treatment of Midazolam in NSC34 cells attacked by reactive oxygen species. Meanwhile, inhibition or activation of the JNK-ERK pathway regulated the protective effect of Midazolam on NSC34 cells with oxidative stress insult. Collectively, this study elucidated a previously unidentified clinical effect of Midazolam, and put forward the great promise that Midazolam may be considered as a potential candidate to the treatment of motor neuron disease.

ITH33/IQM9.21 provides neuroprotection in a novel ALS model based on TDP-43 and Na+/Ca2+ overload induced by VTD

Therapeutic options for amyotrophic lateral sclerosis (ALS) are scarce and controversial. Although the aetiology of neuronal vulnerability is unknown, growing evidence supports a complex network in which multiple toxicity pathways, rather than a single mechanism, are involved in the pathogenesis of ALS. However, most cellular models only explain single pathogenic mechanisms. The present study proposes the two main cytotoxic mechanisms: (1) veratridine (VTD), which induced Na⁺ and Ca²⁺ overload; and (2) the TARD DNA-binding protein 43 (TDP-43) in NSC-34 cell line as an in vitro model of ALS. The study was carried out by MTT as an indirect measurement of cell viability and by flow cytometry to determine cell death stages. The impact of Ca²⁺ overload combined with TDP-43 overexpression increased early apoptosis of NSC-34 cells. Furthermore, we found that ITH33/IQM9.21 (ITH33) exerted a neuroprotective effect in this model by reducing activation of the apoptotic pathway. Therefore, treatment with VTD in TDP-43 overexpressing NSC-34 cells is a good in vitro ALS model that makes it possible to test new neuroprotective compounds such as ITH33.