Effect of selegiline as a monomine oxidase B inhibitor on the expression of neurotrophin mRNA levels in a contusion rat model of spinal cord injury.

OBJECTIVE: Spinal cord injury (SCI) is followed by a cascade of events at the site of injury, including vascular ischemia, an increase in free radicals, inflammation, and neuronal death. In these individuals, protection of nerves and supporting cells, as well as prevention of neuronal damage, may improve recovery opportunities. Neurotrophins are a family of polypeptides that regulate nerve differentiation, growth, and survival. Selegiline is a selective monoamine oxidase B (MAO-B) inhibitor used to treat Parkinson's disease. Selegiline has been found to have neuroprotective properties and may be useful for the expression of neurotrophins. The aim of this study was to evaluate the expression levels of neurotrophin genes in spinal cord rats treated with selegiline. METHODS: Rats were divided into four groups: injury (control), laminectomy, sham (injured rat received 1 ml saline intraperitoneally) and treatment (injured rat received 5 mg/kg selegiline intraperitoneally for 7 days; once a day). The BBB scale (Basso, Beattie and Bresnahan) was performed once a week for 4 weeks to assess motor function after a spinal cord injury. On day 28 after SCI, the rat was sacrificed and the spinal cord lesion removed. A real-time PCR approach was used to assess neurotrophin gene expression. RESULTS: The results showed that administration of selegiline improves locomotor function and increases mRNA levels of BDNF, GDNF, NT-3, and NT-4. CONCLUSION: In summary, the results of this study suggest that selegiline may be an appropriate treatment for spinal cord injuries.

Methamphetamine administration impairs behavior, memory and underlying signaling pathways in the hippocampus.

Methamphetamine (METH) is a strong psychostimulant drug which can essentially affect different brain regions. Hippocampus as one of main components of limbic system plays key roles in processing of short term, long term and spatial memory. Herein, we explored the changes in behavior, synaptic transmission and hippocampal volume along with gliosis following METH treatment. Besides, using genome-wide expression profiling, we applied a pathway-based approach to detect significantly dysregulated signaling pathways. In this regard, we found that METH administration interrupts spatial memory and long term potentiation (LTP). Additionally, stereological analysis revealed a significant alteration in hippocampal volume along with increased gliosis upon METH treatment. We also identified several signaling cascades chiefly related to synaptic transmission which were considerably interrupted in the hippocampus of METH-treated rats. Taken together, our data suggests a potential link between behavioral disruptions and dysregulated signaling pathways.

Lovastatin alters neurotrophin expression in rat hippocampus­derived neural stem cells in vitro.

Neural stem/progenitor cells hold valuable potential for the treatment of neurodegenerative disorders. The modulation of intrinsic growth factor expression, such as neurotrophins and their receptors, is a necessary step in achieving neural stem cells (NSCs) therapy. The statins have recently been reported to provide both anti­inflammatory and neuroprotective effects. In the developing and mature nervous systems, neurotrophic factors are known to impact neuronal growth and survival. In this study, we investigated for a positive effect of lovastatin on the expression of neurotrophins in the neonatal rat hippocampus­derived NSCs. NSCs were isolated and cultured up to passage three. To confirm cellular identity, immunocytochemical evaluation and flow cytometry analysis were performed using specific antibodies. To determine the optimum concentration of lovastatin, the MTT assay was used. Neurotrophin expression was evaluated using quantitative real­time reverse transcription­polymerase chain reaction (RT­qPCR). Flow cytometry results demonstrated that NSCs were positive for nestin, a marker for neural progenitor cells. An increase in cellular viability was observed with a 24 h exposure of lovastatin. Moreover, results showed an increase in mRNA expression for all neurotrophins compared to the control group. Taken together, the results of this study add to the growing body of literature on the neuroprotective effects of statins in neurological disorders. Lovastatin is a promising therapeutic agent for the treatment of neurodegenerative disorders.

Neuroprotective effects of lovastatin in the pilocarpine rat model of epilepsy according to the expression of neurotrophic factors.

Studies have suggested that neurotrophic factors (NTFs) are involved in the status epilepticus development. This indicates their essential role in mediating acquired epileptic conditions. Therefore, modulating the expression of NTFs may inhibit seizure-induced cell loss in the epileptic lesions. In this study, we examined the anti-apoptotic, anti-necrotic and regulatory effects of lovastatin on the expression of NTFs in the pilocarpine rat model of temporal lobe epilepsy (TLE). A total of 32 male Wistar rats were divided into 4 groups (n = 8 per group): i) normal; ii) non-treated epileptic group [intraperitoneal (i.p.) administration of 350-400 mg/kg pilocarpine]; iii) treatment group (pilocarpine-treated rats treated followed by 5 mg/kg lovastatin); and iv) vehicle epileptic rats treated with Carboxymethyl cellulose (CMC). Animals that had a behavioral score of 4-5 according to the Racine scale were selected for study participation. Three days after the first seizure, pilocarpine-treated rats received i.p. injections of lovastatin for 14 days. The rats were killed and prepared for histopathologic analysis as well as real-time RT-PCR 17 days after the first seizure. The results of this study showed increased mRNA expression of glial cell line-derived neurotrophic factor (GDNF) and Ciliary neurotrophic factor (CNTF) and decreased expressions of Brain-derived neurotrophic factor (BDNF), Neurotrophin-3 (NT-3), and Neurotrophin-4 (NT-4) mRNA in the epileptic rats treated with lovastatin. Histological analysis of neurodegeneration in the brain sections showed that the number of hippocampal apoptotic and necrotic cells significantly decreased in the treatment groups. Furthermore, numerical density of neurons per area was significantly higher in the treated groups compared with the untreated groups. Collectively, the results of this study have shown that lovastatin could attenuate seizure-induced expression of neurotrophic factors and consequently reduce hippocampal cell death in the pilocarpine rat model of TLE.

Di-(2-ethylhexyl) Phthalate-Induced Hippocampus-Derived Neural Stem Cells Proliferation.

The brain and spinal cord have a limited capacity for self-repair under damaged conditions. One of the best options to overcome these limitations involves the use of phytochemicals as potential therapeutic agents. In this study, we have aimed to investigate the effects of di-(2-ethylhexyl) phthalate (DEHP) on hippocampus-derived neural stem cells (NSCs) proliferation to search phytochemical candidates for possible treatment of neurological diseases using endogenous capacity. In this experimental study, neonatal rat hippocampus-derived NSCs were cultured and treated with various concentrations of DEHP (0, 100, 200, 400 and 600 µM) and Cirsium vulgare (C. vulgare) hydroethanolic extract (0, 200, 400, 600, 800 and 1000 µg/ml) for 48 hours under in vitro conditions. Cell proliferation rates and quantitative Sox2 gene expression were evaluated using MTT assay and real-time reverse transcription polymerase chain reaction (RT-PCR). We observed the highest average growth rate in the 400 µM DEHP and 800 µg/ml C. vulgare extract treated groups. Sox2 expression in the DEHP-treated NSCs significantly increased compared to the control group. Gas chromatography/mass spectrometry (GC/ MS) results demonstrated that the active ingredients that naturally occurred in the C. vulgare hydroethanolic extract were 2-ethyl-1-hexanamine, n-heptacosane, 1-cyclopentanecarboxylic acid, 1-heptadecanamine, 2,6-octadien-1-ol,2,6,10,14,18,22-tetracosahexaene, and DEHP. DEHP profoundly stimulated NSCs proliferation through Sox2 gene overexpression. These results provide and opportunity for further use of the C. vulgure phytochemicals for prevention and/or treatment of neurological diseases via phytochemical mediated-proliferation of endogenous adult NSCs.