Simultaneous Pericytes and M2 Microglia Transplantation Improve Cognitive Function in Mice Model of mPFC Ischemia.

Cerebral ischemia is one of the major problems threatening global health. Many of the cerebral ischemia survivors would suffer from the physical and cognitive disabilities for their whole lifetime. Cell based-therapies have been introduced as a therapeutic approach for alleviating ischemia-enforced limitations. Photothrombotic stroke model was applied on the left medial prefrontal cortex (mPFC) of adult male BALB/c mice. Then, pericytes isolated from brain microvessels of adult male BALB/c mice, microglia isolated from brain cortices of the neonatal male BALB/c mice, and M2 phenotype shifted microglia by IL-4 treatment were used for transplantation into the injured area after 24 h of ischemia induction. The behavioural outcomes evaluated by social interaction and Barnes tests and the levels of growth associated protein (GAP)-43 and inflammatory cytokine interleukin (IL)-1 protein were assessed by western blotting 7 days after cell transplantation. Animals in both of the microglia + pericytes and microglia M2 + pericytes transplanted groups showed better performance in social memory as well as enhanced spatial learning and memory compared to ischemic controls. Also, improved escape latency was only observed in microglia M2 + pericytes (p < 0.01) group compared to ischemic controls. GAP-43 showed significant protein expression in microglia + pericytes and microglia M2 + pericytes groups compared to the control group. Conversely, IL-1 levels diminished in all of the pericytes microglia + pericytes, and microglia M2 + pericytes groups compared to the ischemic controls. Current study highlights efficiency of M2 microglia and pericytes combinatory transplantation therapeutic role on relieving ischemic stroke outcomes.

Effect of intranasal administration of caffeine on mPFC ischemia­induced cognitive impairment in BALB/c mice.

Caffeine is a psychoactive compound used widely to enhance cognitive functions in human or animal studies. The present study examined the effects of caffeine on cognitive performance and inflammatory factors in mice with medial prefrontal cortex (mPFC) ischemia. Mice underwent a photothrombotic mPFC ischemic stroke and were treated with normal saline or caffeine at different doses intranasally for 7 days. The sham surgery animals received normal saline intranasally. The Morris water maze test and social interaction test were performed to assess spatial and social memories, respectively. In addition, the levels of inflammatory proteins, including tumor necrosis factor­alpha, interleukin­6, and interleukin­10, were measured in the mPFC using immunoblotting. The results showed that mPFC ischemia impaired spatial memory and social behaviors, and caffeine at doses of 0.05 and 0.1 mg improved behavioral outcomes in the ischemic groups. Also, caffeine reversed ischemia­induced high levels of pro­inflammatory biomarkers and enhanced the expression of the anti­inflammatory mediator. Our findings indicate that caffeine alleviated mPFC ischemia­induced memory disturbances, probably through the modulation of the inflammatory mediators.

Cardioprotective effect of Rosa canina L. methanolic extract on heat shock induced cardiomyocyte injury: An experimental study.

Introduction: Overexposure to heat conditions can affect the functioning of the cardiovascular system and may promote cardiovascular disorders. Heat shock induced myocardial injury via increasing endoplasmic reticulum response-mediated apoptosis. This study investigated the impact of pretreatment with Rosa canina (RC), a natural antioxidant, on myocardial damage induced by heat stress exposure and underlying mechanisms in cardiomyocytes in rats. Methods: Sixty adult male Wistar rats were allocated into five groups, including Control: received normal saline (NS), Heat Stress (HS), and HS+RC groups. Animals in the HS groups were subjected to heat stress (43 ºC) for 15 minutes once a day for two weeks. Animals in the HS+RC groups received three doses of RC (250, 500, and 1000 mg/mL) one hour before being subjected to heat shock. The endoplasmic reticulum (ER) transmembrane kinases, including PKR-like endoplasmic reticulum kinase (PERK), immunoreactivity of CCAAT/enhancer-binding protein homologous protein (CHOP), and eukaryotic translation initiation factor 2-alpha (eIF2α) as well as caspase 8 were detected by Western blot. The levels of reactive oxygen species (ROS) were assessed. Moreover, histopathological changes and apoptosis were also assayed in the heart tissue by using histopathological and TUNEL assays. Results: Heat exposure increased the level of ROS and induced oxidative damage in the heart tissue. The results demonstrated that RC administration decreased the overproduction of ROS induced by heat stress in cardiomyocytes. Moreover, heat stress up regulated the expression of p-PERK, p-eIF2α,and CHOP protein while pretreatment with RC decreased expression of ER stress-related markers in cardiomyocytes. Besides, RC diminished heat stress-induced cellular damage and apoptosis associated with inhibition of caspase 8 activation, a pro-apoptotic protein in cardiomyocytes. Conclusion: These findings indicate that RC exerts a protective effect on heart tissue, at least in part,through inactivation of PERK/eIF2α/CHOP pathway or inhibition of ER stress and oxidative stress triggeredapoptosis in cardiomyocytes induced by heat stress.

Physical and cognitive training attenuate hippocampal ischemia-induced memory impairments in rat.

The present study aimed to evaluate the preventive role of physical and cognitive training separately or in combination on memory dysfunction, inflammatory factors and apoptotic markers in the hippocampal-ischemia model of rat. The ischemia model was established by infusion of endothelin-1 (ET-1) into the animal's hippocampus using stereotaxic surgery. Physical, cognitive and combination training groups exposed to voluntary running wheel exercise or modified Barnes maze cognitive task or combination of this interventions for 4 weeks, respectively. Next, Morris water maze (MWM) and novel object recognition (NOR) tasks were used to assess recognition and spatial learning and memories. Western blotting was used to evaluate the protein levels of Nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), tumor necrosis factor-alpha receptor 1 (TNFR1), cytochrome c, Bcl-2-associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), and cleaved caspase-3 in the hippocampal tissue. Hippocampal ischemia significantly impaired recognition and spatial learning and memory with an increase of inflammatory and apoptotic proteins in the hippocampus tissue. Interventions in combination or separately significantly improved performance of ischemia-received animals in memory tasks. Furthermore, both physical and cognitive paradigms also reduced inflammatory and apoptotic factors in the hippocampus of ischemia-received rats. These findings indicate that physical and cognitive training separately or in combination attenuates the deleterious effect of ischemia on cognition through its anti-inflammatory and anti-apoptotic properties.

Nicotinamide Mononucleotide and Melatonin Alleviate Aging-induced Cognitive Impairment via Modulation of Mitochondrial Function and Apoptosis in the Prefrontal Cortex and Hippocampus.

Given the fact that both melatonin and nicotinamide mononucleotide (NMN) act as pleiotropic agents in various age-related cognitive disorders, we aimed to investigate the effect of these compounds separately and together on the cognitive outcomes, mitochondrial function, and apoptosis in aged rats. Forty old and ten young (24 and 3 months old, respectively) male Wistar rats were randomly allocated into five groups: Young+Normal saline (NS), Aged+NS, Aged+Melatonin, Aged+NMN, and Aged+melatonin+NMN. Melatonin (10 mg/kg) and NMN (100 mg/kg) were administered, separately or in combination for 28 every other day in aged animals. The Barnes maze and novel object recognition test were used to assess spatial and episodic-like memories, respectively. Also, apoptosis and alterations in mitochondrial function including reactive oxygen species (ROS) and ATP levels as well as mitochondrial membrane potential were assessed in both prefrontal cortex (PFC) and hippocampus (HIP) regions. Behavioral results revealed that NMN and melatonin separately or in combination, alleviate aging-induced memory impairment. Moreover, agents' co-administration declined mitochondrial dysfunction and apoptotic cell count both in PFC and HIP regions. The agents separately or in combination (more potent) could induce neuroprotective effect and improve learning and memory in aged animals.

Cognitive Rehabilitation Improves Ischemic Stroke-Induced Cognitive Impairment: Role of Growth Factors.

Cognitive dysfunction is the most common nonphysical impairment in the stroke survivors. This impairment has a negative impact on patients' quality of life affects their daily living activities. Both pharmacological and nonpharmacological interventions are employed to improve cognitive impairment. Recently, nonpharmacological interventions have attracted great attention. Cognitive rehabilitation is considered as a therapeutic strategy to improve and maintain cognitive skills in patients with stroke. Enriched environment (EE), as a cognitive rehabilitation strategy, has been shown to facilitate physical, cognitive, as well as social abilities. Moreover, EE has been shown to increase endogenous growth factors. Growth factors have pivotal role in neurogenesis, synaptogenesis, as well as brain remodeling through neuron development, differentiation, and survival. In addition, administration of exogenous growth factors prevents cognitive dysfunction. Here, we review preclinical and clinical evidence of cognitive rehabilitation and role of growth factors in treating poststroke cognitive impairment.

Rosa canina L. methanolic extract prevents heat stress-induced memory dysfunction in rats.

NEW FINDINGS: What is the central question of this study? Heat stress has harmful effects on the brain structure and synaptic density via induction of oxidative stress and neuroinflammation, which result in neuronal damage in the hippocampus and thereby cognitive impairments. In this study, we investigate the effect of Rosa canina treatment on cognitive function in heat stress-exposed rats and its underlying mechanisms. What is the main finding and its importance? We show that R. canina improves cognitive deficits induced by heat stress by attenuation of oxidative stress and neuroinflammation and by upregulation of synaptic proteins in the hippocampus. ABSTRACT: The aim of the study was to evaluate the effects of aqueous methanolic extract of Rosa canina (RC) dried fruits on oxidative stress, inflammation, synaptic degeneration and memory dysfunction induced by heat stress (HS) in rats. Sixty adult male Wistar rats were randomly divided into five groups as follows: the control group received normal saline (NS); the HS group was exposed to heat stress (43°C) for 15 min once a day for 2 weeks; and HS+R groups were exposed to heat stress and received one of three doses (250, 500 or 1000 mg kg-1 ) of RC methanolic extract for 2 weeks. A passive avoidance test and a Y-maze test were performed to assess learning and memory. The levels of reactive oxygen species were assessed. The serum cortisol concentration and hippocampal total antioxidant capacity, superoxide dismutase and glutathione peroxidase were also detected using spectrophotometry. The protein expressions of c-Fos, heat-shock protein-70, tumour necrosis factor-α, growth-associated protein 43, post-synaptic density-95 and synaptophysin were evaluated in the hippocampal tissue. The results showed that RC significantly improved cognitive dysfunction induced by HS, which was accompanied by downregulation of tumour necrosis factor-α and upregulation of growth-associated protein 43 and synaptophysin proteins in the hippocampus of HS-exposed rats. Furthermore, RC significantly attenuated serum cortisol concentrations and upregulated heat shock protein-70 and c-Fos in the hippocampus. In addition, the administration of RC attenuated reactive oxygen species levels and enhanced antioxidant defense in the hippocampus. These findings indicate that RC attenuated the deleterious effect of HS on cognition through its antioxidant properties and by enhancing synaptic function and plasticity.