scholarly journals Intranasal MSC-derived A1-exosomes ease inflammation, and prevent abnormal neurogenesis and memory dysfunction after status epilepticus

2017 ◽  
Vol 114 (17) ◽  
pp. E3536-E3545 ◽  
Author(s):  
Qianfa Long ◽  
Dinesh Upadhya ◽  
Bharathi Hattiangady ◽  
Dong-Ki Kim ◽  
Su Yeon An ◽  
...  

Status epilepticus (SE), a medical emergency that is typically terminated through antiepileptic drug treatment, leads to hippocampus dysfunction typified by neurodegeneration, inflammation, altered neurogenesis, as well as cognitive and memory deficits. Here, we examined the effects of intranasal (IN) administration of extracellular vesicles (EVs) secreted from human bone marrow-derived mesenchymal stem cells (MSCs) on SE-induced adverse changes. The EVs used in this study are referred to as A1-exosomes because of their robust antiinflammatory properties. We subjected young mice to pilocarpine-induced SE for 2 h and then administered A1-exosomes or vehicle IN twice over 24 h. The A1-exosomes reached the hippocampus within 6 h of administration, and animals receiving them exhibited diminished loss of glutamatergic and GABAergic neurons and greatly reduced inflammation in the hippocampus. Moreover, the neuroprotective and antiinflammatory effects of A1-exosomes were coupled with long-term preservation of normal hippocampal neurogenesis and cognitive and memory function, in contrast to waned and abnormal neurogenesis, persistent inflammation, and functional deficits in animals receiving vehicle. These results provide evidence that IN administration of A1-exosomes is efficient for minimizing the adverse effects of SE in the hippocampus and preventing SE-induced cognitive and memory impairments.

Author(s):  
Kavian Ghandehari

The incidence of seizures in relation to stroke is 8.9%, with a frequency of 10.6 and 8.6% in haemorrhagic and ischaemic stroke, respectively. In subarachnoid haemorrhage the incidence is 8.5%. Due to the fact that infarcts are significantly more frequent than haemorrhages, seizures are mainly related to occlusive vascular disease of the brain. The general view is to consider stroke-related seizures as harmless complications in the course of a prolonged vascular disease involving the heart and brain. Seizures can be classified as those of early and those of late onset in a paradigm comparable to post-traumatic epilepsy, with an arbitrary dividing point of two weeks after the event. Most early-onset seizures occur during the first day after the stroke. Late-onset seizures occur three times more often than early-onset ones. A first late-onset epileptic event is most likely to take place between six months and two years after the stroke. However, up to 28% of patients develop their first seizure several years later. Simple partial seizures, with or without secondary generalisation, account for about 50% of total seizures, while complex partial spells, with or without secondary generalisation, and primary generalised tonic–clonic insults account for approximately 25% each. Status epilepticus occurs in 12% of stroke patients, but the recurrence rate after an initial status epilepticus is not higher than after a single seizure. Inhibitory seizures, mimicking transient ischaemic attacks, are observed in 7.1% of cases. The only clinical predictor of late-onset seizures is the initial presentation of partial anterior circulation syndrome due to a territorial infarct. Patients with total anterior circulation syndrome have less chance of developing epileptic spells, not only due to their shorter life expectancy but also due to the fact that the large infarcts are sharply demarcated in these patients. The optimal timing and type of antiepileptic drug treatment for patients with post-stroke seizures is still a controversial issue. Prospective studies in the literature showed that immediate treatment after a first unprovoked seizure does not improve the long-term remission rate. However, because of the physical and psychological influences of recurrent seizures, prophylactic treatment should be considered after a first unprovoked event in an elderly person at high risk of recurrence, taking into consideration the individuality of the patient and a discussion with the patient and his/her family about the risks and benefits of both options latest studies regarding post-stroke seizure treatment showed that 'new-generation' drugs, such as lamotrigine, gabapentin and levetiracetam, in low doses would be reasonable. Although several studies suggest that seizures alter the functional recovery after a stroke, it remains difficult to determine whether or not the occurrence of a second seizure in an untreated stroke patient might hamper the overall outcome. However, repeated seizures and status epilepticus worsen the neurological and mental condition of stroke patienton The decision to initiate antiepileptic drug treatment after a first or a second post-stroke seizure should therefore be individualized, primarily based on the functional impact of the first seizure episode and the patient's preference. Several converging findings suggest that the majority of first-generation antiepileptic drugs, particularly phenytoin, are not the most appropriate choice in stroke patients because of their potential harmful impact on functional recovery and bone health, their suboptimal pharmacokinetic profile and interaction with anticoagulants or salicylates, their greater likelihood to be poorly tolerated, and the lack of level A evidence regarding their specific use in elderly patients. Among the new-generation drugs that do not interact with anticoagulants, antiplatelet agents, or bone health, lamotrigine and gabapentine are the only two drugs that proved to be more effective than immediate-release carbamazepine in elderly patients, providing level A evidence for their use in this indication. In addition, gabapentin remains the only drug that has been specifically evaluated in stroke patients, demonstrating a high rate of long-term seizure freedom. At present, low-dose lamotrigine or gabapentin appears to represent the optimal first-line therapy for post-stroke seizure and epilepsy in elderly patients or in younger patients requiring anticoagulants. However, low-dose extended-release carbamazepine might be a reasonable and less expensive option in patients with appropriate bone health who do not requiring anticoagulat. Based on the stroke management guidelines antiepileptic drugs should not be administered as preventive management in any type of stroke patients without seizure.  


Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 176 ◽  
Author(s):  
Sung Nam ◽  
Misun Seo ◽  
Jin-Seok Seo ◽  
Hyewhon Rhim ◽  
Sang-Soep Nahm ◽  
...  

Ascorbic acid is essential for normal brain development and homeostasis. However, the effect of ascorbic acid on adult brain aging has not been determined. Long-term treatment with high levels of D-galactose (D-gal) induces brain aging by accumulated oxidative stress. In the present study, mice were subcutaneously administered with D-gal (150 mg/kg/day) for 10 weeks; from the seventh week, ascorbic acid (150 mg/kg/day) was orally co-administered for four weeks. Although D-gal administration alone reduced hippocampal neurogenesis and cognitive functions, co-treatment of ascorbic acid with D-gal effectively prevented D-gal-induced reduced hippocampal neurogenesis through improved cellular proliferation, neuronal differentiation, and neuronal maturation. Long-term D-gal treatment also reduced expression levels of synaptic plasticity-related markers, i.e., synaptophysin and phosphorylated Ca2+/calmodulin-dependent protein kinase II, while ascorbic acid prevented the reduction in the hippocampus. Furthermore, ascorbic acid ameliorated D-gal-induced downregulation of superoxide dismutase 1 and 2, sirtuin1, caveolin-1, and brain-derived neurotrophic factor and upregulation of interleukin 1 beta and tumor necrosis factor alpha in the hippocampus. Ascorbic acid-mediated hippocampal restoration from D-gal-induced impairment was associated with an enhanced hippocampus-dependent memory function. Therefore, ascorbic acid ameliorates D-gal-induced impairments through anti-oxidative and anti-inflammatory effects, and it could be an effective dietary supplement against adult brain aging.


1997 ◽  
Vol 10 (4) ◽  
pp. 109-115
Author(s):  
B. Gordon

Recent developments in the functional and neural bases of several aspects of memory are described including long term cortical memory storage, the transition from immediate to permanent memory mediated by medial temporal structures, working memory, memory retrieval, and implicit memory. These are linked to current data on the nature of anterograde and retrograde amnesia in the degenerative diseases, and also to issues in the clinical diagnosis of memory impairments. Understanding the bases of memory can inform the diagnosis of memory impairments in degenerative diseases, and the patterns of impairment seen in the degenerative diseases can help contribute to knowledge of the mechanisms of normal memory.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mariano Guardia Clausi ◽  
Alexander M. Stessin ◽  
Zirun Zhao ◽  
Stella E. Tsirka ◽  
Samuel Ryu

AbstractThe efficacy of combining radiation therapy with immune checkpoint inhibitor blockade to treat brain tumors is currently the subject of multiple investigations and holds significant therapeutic promise. However, the long-term effects of this combination therapy on the normal brain tissue are unknown. Here, we examined mice that were intracranially implanted with murine glioma cell line and became long-term survivors after treatment with a combination of 10 Gy cranial irradiation (RT) and anti-PD-1 checkpoint blockade (aPD-1). Post-mortem analysis of the cerebral hemisphere contralateral to tumor implantation showed complete abolishment of hippocampal neurogenesis, but neural stem cells were well preserved in subventricular zone. In addition, we observed a drastic reduction in the number of mature oligodendrocytes in the subcortical white matter. Importantly, this observation was evident specifically in the combined (RT + aPD-1) treatment group but not in the single treatment arm of either RT alone or aPD-1 alone. Elimination of microglia with a small molecule inhibitor of colony stimulated factor-1 receptor (PLX5622) prevented the loss of mature oligodendrocytes. These results identify for the first time a unique pattern of normal tissue changes in the brain secondary to combination treatment with radiotherapy and immunotherapy. The results also suggest a role for microglia as key mediators of the adverse treatment effect.


2021 ◽  
pp. 105477382110381
Author(s):  
Kelly Haskard-Zolnierek ◽  
Courtney Wilson ◽  
Julia Pruin ◽  
Rebecca Deason ◽  
Krista Howard

Individuals with hypothyroidism suffer from symptoms including impairments to cognition (i.e., “brain fog”). Medication can help reduce symptoms of hypothyroidism; however, brain fog may hinder adherence. The aim of this study was to determine if memory impairment and cognitive failures are related to treatment nonadherence in 441 individuals with hypothyroidism. Participants with a diagnosis of hypothyroidism and currently prescribed a thyroid hormone replacement medication were placed in two groups according to adherence level and compared on validated scales assessing impairments to memory and cognition. Results indicated a significant association between treatment nonadherence and self-reported brain fog, represented by greater cognitive and memory impairments. Nonadherent individuals indicated impairments with prospective, retrospective, and short- and long-term memory; and more cognitive failures, compared to adherent individuals. Findings suggest the importance of interventions to enhance adherence for individuals with brain fog, such as encouraging the use of reminders.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jing Liu ◽  
Zhihao Zhao ◽  
Nasha Qiu ◽  
Quan Zhou ◽  
Guowei Wang ◽  
...  

AbstractAnti-programmed cell death-1 (PD-1)/programmed cell death-ligand 1 (PD-L1) antibodies are currently used in the clinic to interupt the PD-1/PD-L1 immune checkpoint, which reverses T cell dysfunction/exhaustion and shows success in treating cancer. Here, we report a histone demethylase inhibitor, 5-carboxy-8-hydroxyquinoline (IOX1), which inhibits tumour histone demethylase Jumonji domain-containing 1A (JMJD1A) and thus downregulates its downstream β-catenin and subsequent PD-L1, providing an antibody-independent paradigm interrupting the PD-1/PD-L1 checkpoint. Synergistically, IOX1 inhibits cancer cells’ P-glycoproteins (P-gp) through the JMJD1A/β-catenin/P-gp pathway and greatly enhances doxorubicin (DOX)-induced immune-stimulatory immunogenic cell death. As a result, the IOX1 and DOX combination greatly promotes T cell infiltration and activity and significantly reduces tumour immunosuppressive factors. Their liposomal combination reduces the growth of various murine tumours, including subcutaneous, orthotopic, and lung metastasis tumours, and offers a long-term immunological memory function against tumour rechallenging. This work provides a small molecule-based potent cancer chemo-immunotherapy.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Hong Zheng ◽  
Pengtao Xu ◽  
Qiaoying Jiang ◽  
Qingqing Xu ◽  
Yafei Zheng ◽  
...  

Abstract Background Modification of the gut microbiota has been reported to reduce the incidence of type 1 diabetes mellitus (T1D). We hypothesized that the gut microbiota shifts might also have an effect on cognitive functions in T1D. Herein we used a non-absorbable antibiotic vancomycin to modify the gut microbiota in streptozotocin (STZ)-induced T1D mice and studied the impact of microbial changes on cognitive performances in T1D mice and its potential gut-brain neural mechanism. Results We found that vancomycin exposure disrupted the gut microbiome, altered host metabolic phenotypes, and facilitated cognitive impairment in T1D mice. Long-term acetate deficiency due to depletion of acetate-producing bacteria resulted in the reduction of synaptophysin (SYP) in the hippocampus as well as learning and memory impairments. Exogenous acetate supplement or fecal microbiota transplant recovered hippocampal SYP level in vancomycin-treated T1D mice, and this effect was attenuated by vagal inhibition or vagotomy. Conclusions Our results demonstrate the protective role of microbiota metabolite acetate in cognitive functions and suggest long-term acetate deficiency as a risk factor of cognitive decline.


2012 ◽  
Vol 72 (6) ◽  
pp. 943-952 ◽  
Author(s):  
Michael W. Marlatt ◽  
Michelle C. Potter ◽  
Paul J. Lucassen ◽  
Henriette van Praag

2010 ◽  
Vol 23 (5) ◽  
pp. 441-454 ◽  
Author(s):  
Eljim P. Tesoro ◽  
Gretchen M. Brophy

Seizures are serious complications seen in critically ill patients and can lead to significant morbidity and mortality if the cause is not identified and treated quickly. Uncontrolled seizures can lead to status epilepticus (SE), which is considered a medical emergency. The first-line treatment of seizures is an intravenous (IV) benzodiazepine followed by anticonvulsant therapy. Refractory SE can evolve into a nonconvulsive state requiring IV anesthetics or induction of pharmacological coma. To prevent seizures and further complications in critically ill patients with acute neurological disease or injury, short-term seizure prophylaxis should be considered in certain patients.


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