Hazelnut and neuroprotection: Improved memory and hindered anxiety in response to intra-hippocampal Aβ injection

Objectives: Corylus avellana L. (hazelnut) is known to be a delicious and nutritious food. This study was carried out to evaluate the use of hazelnut as a therapy for memory impairment because in Iranian traditional medicine, it is recommended for those suffering from a particular type of dementia, with symptoms of Alzheimer's disease.

Methods: In this study, rats were fed with hazelnut kernel [(without skin) 800?mg/kg/day] during 1 week before stereotaxic surgery to 24?hours before behavioral testing (in general, for 16 consecutive days) and the effect of hazelnut eating on memory, anxiety, neuroinflammation and apoptosis was assessed in the amyloid beta-injected rat.

Results: The results of this study showed that feeding with hazelnut improved memory, (which was examined by using Y-maze test and shuttle box apparatus), and reduced anxiety-related behavior, that was evaluated using elevated plus maze. Also, western blotting analysis of cyclooxygenase-2, interleukin-1β, tumor necrosis factor-α, B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein, and caspase-3 showed that hazelnut has an ameliorating effect on the neuroinflammation and apoptosis caused by Aβ.

Discussion: These ?ndings suggest that hazelnut, as a dietary supplement, improves healthy aging and could be a beneficial diet for the treatment of AD.     

Nutrition for the ageing brain: Towards evidence for an optimal diet

As people age they become increasingly susceptible to chronic and extremely debilitating brain diseases. The precise cause of the neuronal degeneration underlying these disorders, and indeed normal brain ageing remains however elusive. Considering the limits of existing preventive methods, there is a desire to develop effective and safe strategies. Growing preclinical and clinical research in healthy individuals or at the early stage of cognitive decline has demonstrated the beneficial impact of nutrition on cognitive functions. The present review is the most recent in a series produced by the Nutrition and Mental Performance Task Force under the auspice of the International Life Sciences Institute Europe (ILSI Europe). The latest scientific advances specific to how dietary nutrients and non-nutrient may affect cognitive ageing are presented. Furthermore, several key points related to mechanisms contributing to brain ageing, pathological conditions affecting brain function, and brain biomarkers are also discussed. Overall, findings are inconsistent and fragmented and more research is warranted to determine the underlying mechanisms and to establish dose-response relationships for optimal brain maintenance in different population subgroups. Such approaches are likely to provide the necessary evidence to develop research portfolios that will inform about new dietary recommendations on how to prevent cognitive decline.     

腹腔注射LPS建立认知功能障碍相关的中枢神经系统免疫炎症小鼠模型

目的:建立认知功能障碍相关的中枢神经系统免疫炎症小鼠模型。方法:实验采用9~11周的C57/6J雄性小鼠,腹腔注射脂多糖(lipopolysaccharide,LPS)500μg/kg或750μg/kg。采用Morris水迷宫和避暗实验评价小鼠的认知功能,爬杆试验检测小鼠的运动协调性。免疫荧光法观察小鼠海马区神经元特异性微管相关蛋白2(microtubule-associated protein 2,MAP-2)的表达和小胶质细胞的形态和数量。Western blot实验检测小鼠脑组织匀浆液中环氧合酶2(cyclo-oxygenase-2,COX-2)和诱导型一氧化氮合酶(inducible nitric oxide synthase,iNOS)蛋白的表达。结果:Morris水迷宫结果提示,与对照组相比,LPS组小鼠逃避潜伏期延长,目标象限停留时间及穿越目标象限次数减少(P0.05);避暗实验结果提示LPS组均能使小鼠的潜伏期缩短,错误次数增加(P0.05);爬杆实验结果提示LPS组小鼠爬完全程时间高于正常对照组;LPS组小鼠海马区的神经元减少,小胶质细胞增加,COX-2和i NOS蛋白表达增加(P0.01)。结论:腹腔注射LPS可引起小鼠认知功能障碍,模拟认知功能障碍相关的中枢炎症动物模型。     

Human bone marrow mesenchymal stem cells-derived exosomes protect against nerve injury via regulating immune microenvironment in neonatal hypoxic-ischemic brain damage model

Neonatal hypoxic-ischemic (HI) brain injury is a serious injury caused by various perinatal factors, which has become a heavy mental burden to the family. The molecular mechanism underlying neonatal hypoxic-ischemic brain injury remains largely unknown. Human bone marrow mesenchymal stem cells (hBMSCs) have caused wide public concern due to the immunomodulatory properties. Exosomes can polarize human microglia and thus changed it into an anti-inflammatory phenotype to reduce the release of pro-inflammatory factors. However, it is unclear whether hBMSCs-exosomes have effect on neonatal hypoxic-ischemic brain injury. In this study, we aimed at investigating the role of hBMSCs-exosomes in regulating immune response and nerve injury in neonatal hypoxic-ischemic brain damage model. In the research, we identified the exosome secretion of hBMSCs could transferred into human microglia (HMC). Moreover, we determined the importance of hBMSCs-exosomes in regulating HMC polarization and inflammatory response. Our research findings might provide a new insight into slowing the disease progression of neonatal hypoxic-ischemic brain injury.     

Dendrimer-based targeted intravitreal therapy for sustained attenuation of neuroinflammation in retinal degeneration

Retinal neuroinflammation, mediated by activated microglia, plays a key role in the pathogenesis of photoreceptor and retinal pigment epithelial cell loss in age-related macular degeneration and retinitis pigmentosa. Targeted drug therapy for attenuation of neuroinflammation in the retina was explored using hydroxyl-terminated polyamidoamine (PAMAM) dendrimer-drug conjugate nanodevices. We show that, upon intravitreal administration, PAMAM dendrimers selectively localize within activated outer retinal microglia in two rat models of retinal degeneration, but not in the retina of healthy controls. This pathology-dependent biodistribution was exploited for drug delivery, by covalently conjugating fluocinolone acetonide to the dendrimer. The conjugate released the drug in a sustained manner over 90 days. In vivo efficacy was assessed using the Royal College of Surgeons (RCS) rat retinal degeneration model over a four-week period when peak retinal degeneration occurs. One intravitreal injection of 1 μg of FA conjugated to 7 μg of the dendrimer was able to arrest retinal degeneration, preserve photoreceptor outer nuclear cell counts, and attenuate activated microglia, for an entire month. These studies suggest that PAMAM dendrimers (with no targeting ligands) have an intrinsic ability to selectively localize in activated microglia, and can deliver drugs inside these cells for a sustained period for the treatment of retinal neuroinflammation.     

PGE2 EP1 receptor exacerbated neurotoxicity in a mouse model of cerebral ischemia and Alzheimer's disease

Stroke and Alzheimer's disease (AD) are major age-related neurodegenerative diseases that may worsen the prognosis of each other. Our study was designed to delineate the prostaglandin E(2) EP1 receptor role in AD and in the setting of cerebral ischemia. Genetic deletion of the prostaglandin EP1 receptor significantly attenuated the more severe neuronal damage (38.5 ± 10.6%) and memory loss induced by ischemic insult observed in AD transgenic mice (percentage of viable hippocampal CA1 neurons: 11.2 ± 2.9%) when compared with wild type mice (45.1 ± 9.1%). In addition, we found that the amyloid plaques were reduced in EP1 deleted AD mice. β-amyloid-induced toxicity (18.0 ± 7.1%) and Ca(2+) response (91.8 ± 12.9%) were also reduced in EP1(-/-) neurons compared with control neurons in in vitro. Hence, EP1 might mediate most of the toxicity associated with cyclooxygenase-2 and contribute substantially to the cell death pathways in AD and stroke. Exploring potential therapeutic agent targeting EP1 receptor could potentially benefit treatments for stroke and AD patients.     

Microglia-inhibiting activity of Parkinson's disease drug amantadine

Amantadine is currently used as an antiviral and an antiparkinsonian drug. Although the drug is known to bind a viral proton channel protein, the mechanism of action in Parkinson's disease (PD) remains to be determined. This study investigated whether the drug has an inhibitory effect on microglial activation and neuroinflammation, which have been implicated in the progression of neurodegenerative processes. Using cultured microglial cells, it was demonstrated that the drug inhibited inflammatory activation of microglia and a signaling pathway that governs the microglial activation. The drug reduced the expression and production of proinflammatory mediators in bacterial lipopolysaccharide-stimulated microglia cells. The microglia-inhibiting activity of amantadine was also demonstrated in a microglia/neuron coculture and animal models of neuroinflammation and Parkinson's disease. Collectively, our results suggest that amantadine may act on microglia in the central nervous system to inhibit their inflammatory activation, thereby attenuating neuroinflammation. These results provide a molecular basis of the glia-targeted mechanism of action for amantadine.     

Peripheral nerve-derived HIV-1 is predominantly CCR5-dependent and causes neuronal degeneration and neuroinflammation

HIV-related peripheral neuropathy is a major neurological complication of HIV infection, although little is known about its pathogenesis. We amplified HIV-1 C2V3 envelope sequences from peroneal nerves obtained from HIV/AIDS patients. Sequence analysis and infectious recombinant viruses containing peripheral nerve-derived C2V3 sequences indicated a predominance of CCR5-dependent and macrophage-tropic HIV-1, although dual tropic viruses using both CCR5 and CXCR4 were identified. The neuropathogenic effects of recombinant HIV-1 clones were investigated using a novel dorsal root ganglion culture system that was comprised of sensory neurons, macrophages and Schwann cells from transgenic rats expressing human CD4 and CCR5 on monocytoid cells. Despite restricted viral replication, HIV-1 infection caused a reduction in the percentage of neurons with neuritic processes together with significant neurite retraction, which was accompanied by induction of IL-1beta and TNF-alpha expression, depending on the individual virus. Our results suggest that HIV-1 infection of the peripheral nervous system causes axonal degeneration, possibly through the induction of pro-inflammatory cytokines.     

TNF-α诱导的血脑屏障的改变在急性心肌梗死后抑郁中的作用及机制探讨

心肌梗死后抑郁障碍的发生使人们认识到心脑在病理上存在一定联系。患有急性心肌梗死患者具有三倍的风险发展为抑郁。反之,抑郁症状可以增加心血管病的风险。这两种情况的并存与患者预后不良有密切关系。尽管导致这一交互作用的潜在机制尚不明确,但是有人认为炎性反应可能在其中发挥巨大作用。急性心肌梗死诱发的外周组织细胞因子的释放可以引发脑内皮渗漏和血脑屏障完整性的破坏,因此可以诱发神经炎性反应的发生。本文试图从心肌梗死后抑郁发生机制中揭示心脑之间的关系,并为临床心肌梗死后抑郁的治疗提供生物学依据。     

In vivo imaging of neuroinflammation

We briefly outline the rationale for employing positron emission tomography (PET), using the ligand [¹¹C](R)-PK11195, the binding site for which is highly expressed by activated microglia, in order (a) to detect in vivo neuroinflammatory changes occurring in a variety of brain diseases and at different disease stages and (b) to monitor the progression of neuroinflammation as a generic in vivo marker of ‘disease activity’. The use of [¹¹C](R)-PK11195 PET is described as a systematic attempt at measuring the emerging phenomenology of tissue pathology itself—as opposed to measuring, for example, the loss of neuronal function or structure—and as a proof of principle for the clinical utility of imaging glial cells in vivo.