Prevention of in vitro and in vivo acute ischemic neuronal damage by (2S)-1-(4-amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl) phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate (SUN N8075), a novel neuroprotective agent with antioxidant properties

Neuropeptide VGF-Derived Peptide LQEQ-19 has Neuroprotective Effects in an In Vitro Model of Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative disease caused by the loss of upper and lower motor neurons resulting in muscle weakness and paralysis. Recently, VGF, a neuropeptide that is a precursor of bioactive polypeptides, was found to be decreased in ALS patients, and its inducer exerted protective effects in models of ALS. These findings suggested that VGF was involved in the pathology of ALS. Here, we investigated the neuroprotective effects of various VGF-derived peptides in an in vitro ALS model. We applied seven VGF-derived peptides (TLQP-21, AQEE-30, AQEE-11, LQEQ-19, QEEL-16, LENY-13, and HVLL-7) to the motor neuron-derived cell line, NSC-34, expressing SOD1^G93A, which is one of the mutated proteins responsible for familial ALS. Nuclear staining revealed that AQEE-30 and LQEQ-19, which are derived from the C-terminal polypeptide of the VGF precursor protein, attenuated neuronal cell death. Furthermore, immunoblot analysis demonstrated that LQEQ-19 promoted the phosphorylation of Akt and extracellular signal-regulated kinase (ERK) 1/2, and inhibiting these mitogen-activated MAP kinases (MAPKs) with phosphoinositide 3-kinase or MEK/ERK inhibitors, eliminated the neuroprotective effects of LQEQ-19. In conclusion, these results suggest that VGF C-terminal peptides exert their neuroprotective effects via activation of MAPKs such as Akt and ERK1/2. Furthermore, these findings indicate that VGF-derived peptides have potential application in ALS therapy.

VGF and striatal cell damage in in vitro and in vivo models of Huntington's disease

Huntington's disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements, and at present there is no effective treatment for HD. Therapeutic options for HD are limited to symptomatic treatment approaches and there is no cure for this devastating disease. Here, we examined whether SUN N8075, (2S)-1-(4-amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl)phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate, which exerts neuroprotective effects by antioxidant effects and induction of VGF nerve growth factor inducible (VGF), has beneficial effects in STHdh cells derived from striatum of knock-in HD mice and R6/2 HD mice. In an in vitro study, SUN N8075 inhibited the cell death caused by mutant huntingtin (mHtt) and upregulated the VGF mRNA level via the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, 30 amino acid of VGF C-terminal peptide, AQEE-30 inhibited the cell death and the aggregation of mHtt. In an in vivo study, SUN N8075 improved the survival and the clasping response in the R6/2 mice. Furthermore, SUN N8075 increased the number of surviving neurons in the striatum of the R6/2 mice. These findings suggest that SUN N8075 may be an effective candidate for HD treatments.

Recent advances on the neuroprotective potential of antioxidants in experimental models of Parkinson's disease

Parkinson’s disease (PD), a neurodegenerative movement disorder of the central nervous system (CNS) is characterized by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta region of the midbrain. Although the etiology of PD is not completely understood and is believed to be multifactorial, oxidative stress and mitochondrial dysfunction are widely considered major consequences, which provide important clues to the disease mechanisms. Studies have explored the role of free radicals and oxidative stress that contributes to the cascade of events leading to dopamine cell degeneration in PD. In general, in-built protective mechanisms consisting of enzymatic and non-enzymatic antioxidants in the CNS play decisive roles in preventing neuronal cell loss due to free radicals. But the ability to produce these antioxidants decreases with aging. Therefore, antioxidant therapy alone or in combination with current treatment methods may represent an attractive strategy for treating or preventing the neurodegeneration seen in PD. Here we summarize the recent discoveries of potential antioxidant compounds for modulating free radical mediated oxidative stress leading to neurotoxicity in PD.

2-decenoic acid ethyl ester, a compound that elicits neurotrophin-like intracellular signals, facilitating functional recovery from cerebral infarction in mice

In our previous study, we found that trans-2-decenoic acid ethyl ester (DAEE), a derivative of a medium-chain fatty acid, elicits neurotrophin-like signals including the activation of extracellular signal-regulated kinases 1 and 2 (ERK1/2) in cultured mouse cortical neurons. Here, we examined the efficacy of intraperitoneal administration of DAEE on the treatment of a mouse model of the cerebral infarction caused by unilateral permanent middle cerebral artery occlusion (PMCAO). DAEE-treatment (100 μg/kg body weight injected at 0.5, 24, 48, 72 h after PMCAO) significantly restored the mice from PMCAO-induced neurological deficits including motor paralysis when evaluated 48, 72, and 96 h after the PMCAO. Furthermore, DAEE facilitated the phosphorylation of ERK1/2 on the infarction side of the brain when analyzed by Western immunoblot analysis, and it enhanced the number of phosphorylated ERK1/2-positive cells in the border areas between the infarction and non-infarction regions of the cerebral cortex, as estimated immunohistochemically. As the infarct volume remained unchanged after DAEE-treatment, it is more likely that DAEE improved the neurological condition through enhanced neuronal functions of the remaining neurons in the damaged areas rather than by maintaining neuronal survival. These results suggest that DAEE has a neuro-protective effect on cerebral infarction.

SUN N8075, a novel radical scavenger, protects against retinal cell death in mice

In this study, we examined the effect of SUN N8075, a radical scavenger with neuroprotective properties, on murine retinal damage induced by intravitreous injection of N-methyl-d-aspartate (NMDA) or high-intraocular pressure (IOP). In both models, systemic administration of SUN N8075 decreased the cell loss in the ganglion cell layer (GCL) after retinal damage occurred. Moreover, SUN N8075 reduced the number of apoptotic cells and the expression of an oxidative stress marker in GCL in the NMDA model. These findings suggest that SUN N8075 has a neuroprotective effect against retinal damage, presumably via the radical scavenging effect.

Protective effects of SUN N8075, a novel agent with antioxidant properties, in in vitro and in vivo models of Parkinson's disease

SUN N8075 is a novel antioxidant with neuroprotective properties. This study was designed to elucidate its neuroprotective effects against 6-hydroxy dopamine (6-OHDA)-induced cell death and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity (known as in vitro and in vivo models of Parkinson's disease, respectively). In the in vitro study, on human neuroblastoma SH-SY5Y cells, SUN N8075 decreased the hydrogen peroxide (H2O2)-induced production of reactive oxygen species and protected against 6-OHDA-induced cell death. In the in vivo study, SUN N8075, when injected intraperitoneally (i.p.) twice with a 5-h interval, inhibited lipid peroxidation (viz. the production of thiobarbituric acid reactive substance) in the mouse forebrain at 1 h after the second injection. Mice were injected i.p. with MPTP (10 mg/kg) four times at 1-h intervals, and brains were analyzed 7 days later. SUN N8075 at 30 mg/kg (i.p., twice) exhibited a protective effect against the MPTP-induced decrease in tyrosine hydroxylase (TH)-positive fibers in the striatum. Moreover, SUN N8075 at 10 and 30 mg/kg (i.p., twice) had a similar protective effect against the MPTP-induced decrease in TH-positive cells in the substantia nigra. Further, SUN N8075 30 mg/kg (i.p. twice) markedly suppressed the MPTP-induced accumulation of 8-hydroxy-deoxyguanosine (8-OHdG) in the striatum. These findings indicate that SUN N8075 exerts protective effects, at least in part via an anti-oxidation mechanism, in these in vitro and in vivo models of Parkinson's disease.

Computational models of neuronal biophysics and the characterization of potential neuropharmacological targets

The identification and characterization of potential pharmacological targets in neurology and psychiatry is a fundamental problem at the intersection between medicinal chemistry and the neurosciences. Exciting new techniques in proteomics and genomics have fostered rapid progress, opening numerous questions as to the functional consequences of ligand binding at the systems level. Psycho- and neuro-active drugs typically work in nerve cells by affecting one or more aspects of electrophysiological activity. Thus, an integrated understanding of neuropharmacological agents requires bridging the gap between their molecular mechanisms and the biophysical determinants of neuronal function. Computational neuroscience and bioinformatics can play a major role in this functional connection. Robust quantitative models exist describing all major active membrane properties under endogenous and exogenous chemical control. These include voltage-dependent ionic channels (sodium, potassium, calcium, etc.), synaptic receptor channels (e.g. glutamatergic, GABAergic, cholinergic), and G protein coupled signaling pathways (protein kinases, phosphatases, and other enzymatic cascades). This brief review of neuromolecular medicine from the computational perspective provides compelling examples of how simulations can elucidate, explain, and predict the effect of chemical agonists, antagonists, and modulators in the nervous system.