Mesenchymal stem cells improve ischemic stroke injury by anti-inflammatory properties in rat model of middle cerebral artery occlusion

Background: Ischemic stroke is a major cause of permanent disability and inflammation has a prominent role in stroke pathology. Stem cell therapy is a new approach for stroke treatment. Mesenchymal stem cells (MSCs) are appropriate for this approach due to neuroprotective and immunomodulatory effects. Objectives: In this experimental study, the neuroprotective effects of mesenchymal stem cells (MSCs) on brain injury after transient middle cerebral artery occlusion (tMCAO) in rats was investigated with emphasis on inflammatory factors. Methods: Mesenchymal Stem Cells were isolated from bone marrow of rats and expanded by cell culture. Thirty-six male Wistar rats were randomly selected and divided to 6 groups. The MCAO model was performed in 4 groups with 24 and 72 hours of reperfusion. A single infusion of 2 × 106 MSCs was transplanted in one of the 24-hour and 72-hour groups and others received saline. In the sham groups, surgery was done without MCAO. Behavioral tests were evaluated and infarct volume was measured by staining of brain sections. Serum levels of Interleukin (IL) 1β and Tumor necrosis factor (TNF) α were measured by the enzyme linked immunosorbent assay (ELISA). Relative expression of Interleukin (IL)1β, tumor necrotizing factor (TNF)α, and IL6 genes were assessed in penumbra of the ischemic region using real time polymerase chain reaction (PCR). Results: The study results indicated that total behavioral scores were increased 72 hours after MSC transplantation (14.5 ± 2.0, P < 0.01). Moreover, MSCs decreased the infarct volume both 24 hours (18.82 ± 1.58, P < 0.01) and 72 hours (14.4 ± 1.53, P < 0.05) after MCAO. Serum levels of IL-1β and TNFα were increased after MCAO, yet MSCs transplantation decreased IL-1β (368.3 ± 109.5, P < 0.001) and TNFα (126.9 ± 38.6, P < 0.01) compared to saline. Also, relative gene expression of IL1β, TNFα, and IL6 was decreased by MSCs transplantation (P < 0.05). Conclusions: The MSCs had a neuroprotective effect in ischemic stroke via modulation of inflammatory response, and serum levels of IL1β and TNFα could be used as markers for evaluating anti-inflammatory effects of MSCs

Role of Steroid Therapy after Ischemic Stroke by N-Methyl-D-Aspartate Receptor Gene Regulation

Background: Stroke is the main cause of cerebrovascular disease mortality. Prolonged stimulation of N-methyl-D-aspartate (NMDA) receptor subtypes by the accumulation of glutamate neurotransmitter in the extracellular space after a stroke could activate cell death pathways. It is reported that progesterone provides different mechanisms of neuroprotection and could be considered as a candidate for stroke treatment. This study aimed to investigate progesterone impact on the expression of NMDA receptor subunits NR1, NR2(A and B), NR3 (A and B) after an experimental model of ischemic stroke which is followed by an in silico analysis. Methods: Progesterone was introduced subcutaneously after transient middle cerebral artery occlusion in male rats. After a period of reperfusion, a set of behavioral tests was performed to evaluate the postischemic neurological deficits. The 2,3,5-triphenyltetrazolium chloride staining method was done for quantification of infarct volume and gene expression analysis was performed in the penumbra region using reverse transcription polymerase chain reaction for NMDA receptor subunits. An AutoDock tool was employed to perform molecular docking analyses for evaluation of progesterone interaction with NMDA receptor. Results: Cerebral ischemia caused a significant downregulation in NR1, NR2A, NR2B and a profound upregulation of NR3B in cortical penumbraregion. Treatment with progesterone resu lted in upregulation of NR1, NR2A, and NR3B which could explain a possible the neuroprotection of steroids via binding to NMDA glutamate receptor. In addition, in silico analysis revealed that progesterone could strongly interact with NR1/NR2B and NR2A. Conclusion: The findings elucidate a new aspect of the neuroprotective mechanism of progesterone via NMDA receptors gene regulation. Keywords: Stroke NMDA receptor Progesterone Gene expressio

Mesenchymal stem cells improve ischemic stroke injury by anti-inflammatory properties in rat model of middle cerebral artery occlusion

Background: Ischemic stroke is a major cause of permanent disability and inflammation has a prominent role in stroke pathology. Stem cell therapy is a new approach for stroke treatment. Mesenchymal stem cells (MSCs) are appropriate for this approach due to neuroprotective and immunomodulatory effects. Objectives: In this experimental study, the neuroprotective effects of mesenchymal stem cells (MSCs) on brain injury after transient middle cerebral artery occlusion (tMCAO) in rats was investigated with emphasis on inflammatory factors. Methods: Mesenchymal Stem Cells were isolated from bone marrow of rats and expanded by cell culture. Thirty-six male Wistar rats were randomly selected and divided to 6 groups. The MCAO model was performed in 4 groups with 24 and 72 hours of reperfusion. A single infusion of 2�106 MSCs was transplanted in one of the 24-hour and 72-hour groups and others received saline. In the sham groups, surgery was done without MCAO. Behavioral tests were evaluated and infarct volume was measured by staining of brain sections. Serumlevels of Interleukin (IL) 1βand Tumornecrosis factor (TNF)αwere measured by the enzymelinked immunosorbent assay (ELISA). Relative expression of Interleukin (IL)1β, tumor necrotizing factor (TNF)α, and IL6 genes were assessed in penumbra of the ischemic region using real time polymerase chain reaction (PCR). Results: The study results indicated that total behavioral scores were increased 72 hours after MSC transplantation (14.5±2.0, P &lt; 0.01). Moreover, MSCs decreased the infarct volume both 24 hours (18.82 ± 1.58, P &lt; 0.01) and 72 hours (14.4 ± 1.53, P &lt; 0.05) after MCAO. Serum levels of IL-1βand TNFαwere increased afterMCAO, yet MSCs transplantation decreased IL-1β(368.3±109.5, P &lt; 0.001) and TNFα (126.9 ± 38.6, P &lt; 0.01) compared to saline. Also, relative gene expression of IL1β, TNFα, and IL6 was decreased by MSCs transplantation (P &lt; 0.05). Conclusions: The MSCs had a neuroprotective effect in ischemic stroke via modulation of inflammatory response, and serum levels of IL1β and TNFα could be used as markers for evaluating anti-inflammatory effects of MSCs. © 2018, Iranian Red Crescent Medical Journal

Exposure to nanoscale diesel exhaust particles: Oxidative stress, neuroinflammation, anxiety and depression on adult male mice

ABSTRACT Exposure to nanoscale diesel engines exhausted particles (DEPs) is a well-recognized risk factor for respiratory and cardiovascular diseases. Rodents as commonly used models for urban air pollution in health effect studies demonstrate constant stimulation of inflammatory responses in the main areas of the brain. Nevertheless, the primary effect of diesel exhaust particulate matter on some of the brain regions and relation by behavioral alterations still remains untouched. We evaluated the brain regional in flammatory responses to a nanosized subfraction of diesel engines exhaust particulate matter (DEPs < 200 nm) in an adult male mice brain. Adult male mice were exposed to DEPs for 3, 6, and 8 h per day, 12 weeks and five days per week. Degree of anxiety and the depression by elevated plus maze and Forced Swimming Test respectively (FST) did measurement. After behavior tests, the plasma and some of the brain regions such as olfactory bulb (OB) and hippocampus (HI) were analyzed for oxidative stress and in flammatory responses. The inflammation and oxidative stress changes in OB and HI, markedly coincides with the results of behavioral alterations. These responses corresponded with rapid induction of MDA and nitrite oxide (NO) in brain regions and neuronal nitric oxide synthase (nNOS) mRNA followed by IL6, IL1 α , and TNF α in OB and HI. The different times of DEPs exposure, leads to oxidative stress and inflammatory in plasma and brain regions. That this cumulative transport of inhaled nanoscale DEPs into the brain and creating to inflammation responses of brain regions may cause problems of brain function and anxiety and depression. Keywords: Air pollution Nanoscale diesel exhaust particles Oxidative stress Nanotoxicology Anxiety Depressio

Prenatal exposure to diesel exhaust particles causes anxiety, spatial memory disorders with alters expression of hippocampal pro-inflammatory cytokines and NMDA receptor subunits in adult male mice offspring

Air pollution by Diesel exhaust (DE) consists of gaseous compounds and diesel exhaust particles (DEPs). Previous studies show associations between prenatal exposure to diesel exhaust affects the central nervous system (CNS). However, there was not reported that these effects were caused by gaseous compounds, diesel exhaust particles, or both. A limited number of studies in rodent models have shown that exposure to DEPs can result in CNS. Here, we explored the effects of prenatal exposure to DEPs on anxiety and learning and memory in NMRI mice male offspring. Three groups of pregnant mice were exposed to 350�400 μg DEPs/m 3 for 2, 4 and 6 h daily in a closed system room. We examined anxiety and learning and memory in 8-to-9-week-old male offspring using the Elevated plus maze and Morris water maze (MWM) test. Hippocampi were isolated after the behavioral tests and measured pro-inflammatory cytokines and N-methyl-D-aspartate (NMDA) receptor expression by quantitative RT-PCR analysis. Mice exposed to DEPs in utero showed de�cits in the Elevated plus maze and Morris water maze test. In addition, DEPs exposed mice exhibited decreased hippocampal NR2A and NR3B expression. Taken together, our data suggest that maternal DEP exposure is associated with anxiety, disrupts learning and memory and reduction hippocampal NR2A and NR3B expression in male offspring. © 201

Role of toll-like receptors 2 and 4 in the neuroprotective effects of bone marrow�derived mesenchymal stem cells in an experimental model of ischemic stroke

Objective: Ischemic stroke is a major cause of death and prolonged disability worldwide. Inflammation plays an important role in post-ischemic injury. Mesenchymal stem cells (MSCs) have protective effects in stroke treatment due to their anti-inflammatory properties. Toll-like receptors (TLRs) 2 and 4 are two innate immune receptors that trigger inflammatory processes. Here, we investigated the association of these receptors with the protective effect of MSCs after middle cerebral artery occlusion (MCAO) in rats. Methods: MSCs were isolated from the bone marrow of young rats and expanded in vitro. A model of ischemic stroke was performed by transient MCAO with 24 or 72 hours of reperfusion. Two hours after ischemia/reperfusion (I/R), the rats received MSCs or saline via tail vein and the sham group underwent surgery without MCAO. The relative gene expressions of TLR2, TLR4, and MyD88 were evaluated in the ischemic penumbra by the real-time PCR technique. Active astrocyte and microglia and TLR-expressing cells were detected by immunohistochemistry (IHC). Results: MSCs significantly decreased the genes expression of TLR2 (P = 0.006), TLR4 (P = 0.038), and MyD88 (P = 0.009) after their upregulation by I/R. Moreover, the IHC results indicated that glial fibrillary acidic protein (GFAP) and ionized calcium-binding adapter molecule 1 (Iba-1) positive cells were significantly increased by I/R (P < 0.001), and MSCs significantly decreased the number of GFAP (P = 0.003), Iba-1 (P = 0.001), TLR2 (P = 0.004), and TLR4 (P = 0.007) positive cells 72 hours after I/R. Conclusion: The neuroprotective effect of MSCs in brain ischemic injury is associated with its anti-inflammatory effects and modulation of the activity of immune cells. Inhibition of TLR2 and TLR4 expression is one of the possible mechanisms of this protective effect. © 2018 Wiley Periodicals, Inc

Neuroprotective effect of melatonin on radiation-induced oxidative stress and apoptosis in the brainstem of rats

This study aimed to determine the effects of melatonin on irradiation-induced apoptosis and oxidative stress in the brainstem region of Wistar rats. Therefore, the animals underwent whole-brain X-radiation with a single dose of 25 Gy in the presence or absence of melatonin pretreatment at a concentration of 100 mg/kg BW. The rats were allocated into four groups (10 rats in each group): namely, vehicle control (VC), 100 mg/kg of melatonin alone (MLT), irradiation-only (RAD), and irradiation plus 100 mg/kg of melatonin (RAM). An hour before irradiation, the animals received intraperitoneal (IP) melatonin and then were killed after 6 hr, followed by measurement of nitric oxide (NO), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), and total antioxidant capacity (TAC) in the brainstem region. Furthermore, the western blot analysis technique was performed to assess the caspase-3 expression level. Results showed significantly higher MDA and NO levels in the brainstem tissues for the RAD group when compared with the VC group (p <.001). Moreover, the irradiated rats exhibited a significant decrease in the levels of CAT, SOD, GPx, and TAC (p <.01, p <.001, p <.001, and p <.001, respectively) in comparison to the VC group. The results of apoptosis assessment revealed that the expression level of caspase-3 significantly rose in the RAD group in comparison with the VC group (p <.001). Pretreatment with melatonin ameliorated the radiation-induced adverse effects by decreasing the MDA and NO levels (p <.001) and increasing the antioxidant enzyme activities (p <.001). Consequently, the caspase-3 protein expression level in the RAM group showed a significant reduction in comparison with the RAD group (p <.001). In conclusion, melatonin approximately showed a capacity for neuroprotective activity in managing irradiation-induced oxidative stress and apoptosis in the brainstem of rats; however, the use of melatonin as a neuroprotective agent in humans requires further study, particularly clinical trials. © 2020 Wiley Periodicals, Inc

Estrogen and progesterone attenuate glutamate neurotoxicity via regulation of EAAT3 and GLT-1 in a rat model of ischemic stroke

Objective(s): Glutamate is the most widespread neurotransmitter in the central nervous system and has several functions as a neuromodulator in the brain although in pathological conditions like ischemia it is excessively released causing cell death. Under physiological conditions, glutamate is rapidly scavenged from the synaptic cleft by excitatory amino-acid transporters (EAATs). An imbalance in glutamatergic neurotransmission could influence the expression of glutamate transporters and is a pathological feature in several neurological disorders. It has been shown that estrogen and progesterone act as neuroprotective agents after brain injury. This study aims to investigate the role of hormone therapy after middle cerebral artery occlusion (tMCAO) in the expression of GLT-1 and EAAT3 as glutamate transporters. Materials and Methods: Middle cerebral artery occlusion technique was performed in Wistar rats in order to induce focal cerebral ischemia. Estrogen, progesterone, and a combination of both hormones were injected subcutaneously in the early minutes of reperfusion. Sensorimotor functional tests were performed and infarct volume was calculated by TTC staining of brain section. Gene and protein expression of EAAT3 and GLT-1 were evaluated by RT-PCR, immunoblotting, and immunohistochemistry. Results: Behavioral scores were increased and infarct volume was reduced by hormone therapy. RT-PCR, immunoblotting, and immunohistochemistry data showed that the expression of GLT-1 and EAAT3 increased after ischemia. Also, estrogen and progesterone treatment enhanced mRNA and protein expression levels of GLT-1 and EAAT3 compared with ischemia. Conclusion: Steroids may protect brain tissue against ischemia-induced tissue degeneration by decreasing extracellular glutamate levels through the induction of glutamate transporters. © 2020 Mashhad University of Medical Sciences. All rights reserved

Prenatal exposure to diesel exhaust particles causes anxiety, spatial memory disorders with alters expression of hippocampal pro-inflammatory cytokines and NMDA receptor subunits in adult male mice offspring

Air pollution by Diesel exhaust (DE) consists of gaseous compounds and diesel exhaust particles (DEPs). Previous studies show associations between prenatal exposure to diesel exhaust affects the central nervous system (CNS). However, there was not reported that these effects were caused by gaseous compounds, diesel exhaust particles, or both. A limited number of studies in rodent models have shown that exposure to DEPs can result in CNS. Here, we explored the effects of prenatal exposure to DEPs on anxiety and learning and memory in NMRI mice male offspring. Three groups of pregnant mice were exposed to 350�400 μg DEPs/m 3 for 2, 4 and 6 h daily in a closed system room. We examined anxiety and learning and memory in 8-to-9-week-old male offspring using the Elevated plus maze and Morris water maze (MWM) test. Hippocampi were isolated after the behavioral tests and measured pro-inflammatory cytokines and N-methyl-D-aspartate (NMDA) receptor expression by quantitative RT-PCR analysis. Mice exposed to DEPs in utero showed de�cits in the Elevated plus maze and Morris water maze test. In addition, DEPs exposed mice exhibited decreased hippocampal NR2A and NR3B expression. Taken together, our data suggest that maternal DEP exposure is associated with anxiety, disrupts learning and memory and reduction hippocampal NR2A and NR3B expression in male offspring. © 201

Exposure to nanoscale diesel exhaust particles: Oxidative stress, neuroinflammation, anxiety and depression on adult male mice

Exposure to nanoscale diesel engines exhausted particles (DEPs) is a well-recognized risk factor for respiratory and cardiovascular diseases. Rodents as commonly used models for urban air pollution in health effect studies demonstrate constant stimulation of inflammatory responses in the main areas of the brain. Nevertheless, the primary effect of diesel exhaust particulate matter on some of the brain regions and relation by behavioral alterations still remains untouched. We evaluated the brain regional inflammatory responses to a nanosized subfraction of diesel engines exhaust particulate matter (DEPs < 200 nm) in an adult male mice brain. Adult male mice were exposed to DEPs for 3, 6, and 8 h per day, 12 weeks and five days per week. Degree of anxiety and the depression by elevated plus maze and Forced Swimming Test respectively (FST) did measurement. After behavior tests, the plasma and some of the brain regions such as olfactory bulb (OB) and hippocampus (HI) were analyzed for oxidative stress and inflammatory responses. The inflammation and oxidative stress changes in OB and HI, markedly coincides with the results of behavioral alterations. These responses corresponded with rapid induction of MDA and nitrite oxide (NO) in brain regions and neuronal nitric oxide synthase (nNOS) mRNA followed by IL6, IL1α and TNFα in OB and HI. The different times of DEPs exposure, leads to oxidative stress and inflammatory in plasma and brain regions. That this cumulative transport of inhaled nanoscale DEPs into the brain and creating to inflammation responses of brain regions may cause problems of brain function and anxiety and depression. © 2018 Elsevier Inc