Brain Hippocampus Tissues Research Articles

Brain Targeting of Citicoline Sodium via Hyaluronic Acid-Decorated Novel Nano-Transbilosomes for Mitigation of Alzheimer's Disease in a Rat Model: Formulation, Optimization, in vitro and in vivo Assessment.

Alzheimer's disease (AD) is one of the furthermost advanced neurodegenerative disorders resulting in cognitive and behavioral impairment. Citicoline sodium (CIT) boosts the brain's secretion of acetylcholine, which aids in membrane regeneration and repair. However, it suffers from poor blood-brain barrier (BBB) permeation, which results in lower levels of CIT in the brain. This study targeted to encapsulate CIT into novel nano-platform transbilosomes decorated with hyaluronic acid CIT-HA*TBLs to achieve enhanced drug delivery from the nose to the brain. A method of thin-film hydration was utilized to prepare different formulae of CIT-TBLs using the Box-Behnken design. The optimized formula was then hyuloranated via integration of HA to form the CIT-HA*TBLs formula. Furthermore, AD induction was performed by aluminum chloride (Alcl3), animals were allocated, and brain hippocampus tissue was isolated for ELISA and qRT-PCR analysis of malondialdehyde (MDA), nuclear factor kappa B (NF-kB), and microRNA-137 (miR-137) coupled with immunohistochemical amyloid-beta (Aβ1-42) expression and histopathological finding. The hyuloranated CIT-HA*TBLs formula, which contained the following ingredients: PL (300 mg), Sp 60 (43.97 mg), and SDC (20 mg). They produced spherical droplets at the nanoscale (178.94 ±12.4 nm), had a high entrapment efficiency with 74.92± 5.54%, had a sustained release profile of CIT with 81.27 ±3.8% release, and had ex vivo permeation of CIT with 512.43±19.58 μg/cm2. In vivo tests showed that CIT-HA*TBL thermogel dramatically reduces the hippocampus expression of miR-137 and (Aβ1-42) expression, boosting cholinergic neurotransmission and decreasing MDA and NF-kB production. Furthermore, CIT-HA*TBLs thermogel mitigate histopathological damage in compared to the other groups. Succinctly, the innovative loading of CIT-HA*TBLs thermogel is a prospectively invaluable intranasal drug delivery system that can raise the efficacy of CIT in Alzheimer's management.

Natural Killer Cells Improve Cognitive Function and Support to Induce Amyloid Beta Clearance by Functional Recovery of Impaired Microglia in Natural Killer Cell‐treated Alzheimer’s Diseases Mouse Model

AbstractBackgroundDysfunction of microglia that plays a pivotal role in amyloid beta clearance is recognized to be involved in pathological progression of the Alzheimer’s diseases. Natural killer (NK) cells participate in homeostatic immune‐modulation and immune‐surveillance by secreting immune‐boosting signaling molecules. These molecules can serve as cell‐based therapeutics for AD. In this study, we found that the activated NK cells eliminated Aβ plaques, resulting in a marked improvement in behavior in mice with AD. This improvement may be associated with the recovery in microglial function due to the upregulation of phagocytic activity and autophagy genes.MethodNK cells were isolated, using a negative selection process, from the spleens of BALB/c mice and subsequently expanded to 1×108 cells.ResultThe cultured NK cells were intravenously administered into APP/PS1 mutant mice. There was dramatic reduction of Aβ deposition in the cortex and dentate gyrus areas of the brain in these mice following the NK cell treatment. While phosphate‐buffered saline APP/PS1 control mice exhibited learning deficits in the escape platform, the NK cell‐treated mice showed reduced escape latency in the Morris water maze test. Mouse microglia, in the AD model, were isolated using CD11b positive magnetic activated cell sorting method. RNA sequencing was performed using total RNA isolated from mouse brain hippocampus tissue, to explore differential gene expression levels. Hierarchical cluster heat maps revealed the recovered gene populations in the NK‐treated microglial group. The percentage of genes upregulated in the total gene ontology groups were significantly altered in NK treated/sham ratio group (i.e., 171 upregulated immune response‐related genes). The homeostatic and disease‐associated microglia (DAM)‐related genes that were increased in microglia isolated from APP/PS1 mouse brain were downregulated after NK treatment. KEGG pathway analysis projected the autophagy signaling pathways as critical pathways associated with amyloid beta clearance. Our analysis showed that treatment of mice with NK cells recovered gene signatures involved in phagocytic activity.ConclusionThese findings show that NK cells, which are known to have low in vivo toxicity, could be a potential therapeutic option for AD that could be rapidly translated to the clinic.

Protective effects of cerebrolysin against chemotherapy (carmustine) induced cognitive impairment in Albino mice

Chemotherapy-induced cognitive impairment (CICI) comprises different neurological problems, including difficulty in learning new things, concentrating and making decisions that affect daily life activities. Clinical reports indicate that around 70% of cancer patients receiving chemotherapy suffer from cognitive impairment. The purpose of the present study is to examine the effects of widely used anticancer medication (Carmustine) on cognitive function using mice model and investigation of the neuroprotective effects of Cerebrolysin (CBN). Cerebrolysin (CBN) is a mixture of several neurotrophic factors and active peptides with anti-inflammatory, antioxidant, and neuroprotective actions. Our study aimed to establish a mice model of Carmustine (BCNU)-induced cognitive deficits and determine the protective effects of CBN. BCNU (10 mg/kg, i.v.) was administered to mice for 28 days, and behavioral parameters were measured on a weekly basis. CBN (44 and 88 mg/kg, i.p.) was administered daily from day 1 to 28 to BCNU treatment mice. All animals were sacrificed on day 29 and brain hippocampus tissues were used for biochemical, neuroinflammatory, neurotransmitters analysis. BCNU administration animals showed impaired cognition and memory, confirmed from behavioral analysis. Further, BCNU increased oxidative stress, inflammatory cytokines release and altered neurotransmitters concentration as compared to the control group (p < 0.01). However, mice treated with CBN (44 and 88 mg/kg, i.p.) significantly and dose-dependently improved cognitive functions, reduced oxidative stress markers, inflammatory cytokines and restored neurotransmitters concentration as compared to BCNU administered mice (p < 0.05). The finding of current study suggested that CBN could be the promising compound to reverse cognitive impairment associated with use of chemotherapy.

Neuroprotective Effect of Fucoxanthin against Intracerebroventricular Streptozotocin (ICV-STZ) Induced Cognitive Impairment in Experimental Rats.

Alzheimer's disease (AD) is a neurological disorder characterized by loss of memory and cognitive functions caused by oxidative stress, neuroinflammation, change in neurotransmitter levels, and excessive deposition of Aβ(1-42) plaques. Fucoxanthin is a carotenoid with potential antioxidant, anti-inflammatory, and neuroprotective actions. In the present study, fucoxanthin was employed as a protective strategy in Intracerebroventricular Streptozotocin (ICV-STZ) induced experimental model of cognitive impairment. STZ was injected twice ICV (3 mg/kg) on alternate days 1 and 3, and Wistar rats were evaluated for the memory analysis using Morris water maze and elevated plus-maze. Fucoxanthin at low 50 mg/kg, p.o. and high dose 100 mg/kg, p.o. was administered for 14 days. All animals were sacrificed on day 29, and brain hippocampus tissue after isolation was used for biochemical (MDA, nitrite, GSH, SOD and Catalase), neuroinflammatory (TNF-α, IL-1β, and IL-6), neurotransmitters (ACh, GABA Glutamate), Aβ(1-42) and Tau protein measurements. STZ-infused rats showed significant impairment in learning and memory, increased oxidative stress (MDA, nitrite), reduced antioxidant defense (GSH, SOD and Catalase), promoted cytokine release, and change in neurotransmitters level. However, fucoxanthin improved cognitive functions, restored antioxidant levels, reduced inflammatory markers dose-dependently, and restored neurotransmitters concentration. The finding of the current study suggests that fucoxanthin could be the promising compound for improving cognitive functions through antioxidant, anti-inflammatory, and neuroprotective mechanisms, and inhibition of acetylcholinesterase (AChE) enzyme activities, Aβ(1-42) accumulation, and tau protein.

Evaluating behavioral, biochemical and histopathological effects of the MgO nanoparticles administration on memory in the Alzheimer-like model of male rat

Objective(s): This study has investigated the effects of acute and chronic administration of MgO nanoparticles (NP), on the memory, serum magnesium ions level, total antioxidant capacity and histopathological changes of the rat hippocampus in the Alzheimer-like model induced by streptozotocin (STZ). Materials and Methods: Adult male Wistar rats divided into: control, sham (STZ+ saline) and MgO NP 1 and 5 mg/kg groups. To induce Alzheimer’s disease, all rats except control group, received STZ (3 mg/kg/ 5 µl of saline) into the lateral ventricles during anesthesia. One week after surgery, passive avoidance learning was started by shuttle box device and saline or MgO NP acutely and chronically was administered after training. Memory tests were done at 90 minutes and 24 hours after training and one week after chronic administration. Immediately after the memory test, serum magnesium levels and total antioxidant capacity were measured, also the brain hippocampus tissue was removed for histopathological evaluation. STZ significantly impairs memory up to a week after the training. Results: Acute and chronic administration of MgO NP significantly improved short and long-term memory in the Alzheimer’s rats. Serum magnesium level decreased in the Alzheimer’s rats and MgO NP increased it in a dose-dependent manner. MgO NP 1 mg/kg significantly increased serum total antioxidant capacity. MgO NP improved STZ-induced cell lesions in different parts of the hippocampus. Conclusions: It seems that MgO NP have the potential to improve brain lesions that have led to loss of memory and can be considered as an important component candidate for Alzheimer’s disease.

Functional Network of the Long Non-coding RNA Growth Arrest-Specific Transcript 5 and Its Interacting Proteins in Senescence.

Increasing studies show that long non-coding RNAs (lncRNAs) play essential roles in various fundamental biological processes. Long non-coding RNA growth arrest-specific transcript 5 (GAS5) showed differential expressions between young and old mouse brains in our previous RNA-Seq data, suggesting its potential role in senescence and brain aging. Examination using quantitative reverse transcription-polymerase chain reaction revealed that GAS5 had a significantly higher expression level in the old mouse brain hippocampus region than the young one. Cellular fractionation using hippocampus-derived HT22 cell line confirmed its nucleoplasm and cytoplasm subcellular localization. Overexpression or knockdown of GAS5 in HT22 cell line revealed that GAS5 inhibits cell cycle progression and promotes cell apoptosis. RNA-Seq analysis of GAS5-knockdown HT22 cells identified differentially expressed genes related to cell proliferation (e.g., DNA replication and nucleosome assembly biological processes). RNA pull-down assay using mouse brain hippocampus tissues showed that potential GAS5 interacting proteins could be enriched into several Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and some of them are involved in senescence-associated diseases such as Parkinson’s and Alzheimer’s diseases. These results contribute to understand better the underlying functional network of GAS5 and its interacting proteins in senescence at brain tissue and brain-derived cell line levels. Our study may also provide a reference for developing diagnostic and clinic biomarkers of GAS5 in senescence and brain aging.

Neuroprotection of Tropical Fruit Juice Mixture via the Reduction of iNOS Expression and CRH Level in β-Amyloid-Induced Rats Model of Alzheimer's Disease.

This study aimed to determine the effects of tropical fruit juice mixture (pomegranate, white guava, and Roselle) on biochemical, behavioral, and histopathological changes of β-amyloid- (Aβ-) induced rats. Formulation 8 (F8) of tropical fruit juice mixture was chosen for this present study due to its high phenolic content and antioxidant capacity. Forty Wistar male rats were divided into five groups: dPBS (sham-operated control), dAβ (Aβ control), JPBS (F8 and PBS), JAβ (F8 and Aβ), and IBFAβ (ibuprofen and Aβ). F8 (5 ml/kg BW), and ibuprofen (10 ml/kg BW) was given orally daily for four weeks before the intracerebroventricular infusion of Aβ for two weeks. Histological analysis and neuronal count of hippocampus tissue in the Cornu Ammonis (CA1) region showed that supplementation with F8 was able to prevent Aβ-induced tissue damage and neuronal shrinkage. However, no significant difference in locomotor activity and novel object recognition (NOR) percentage was detected among different groups at day 7 and day 14 following Aβ infusion. Only effect of time differences (main effect of day) was observed at day 7 as compared to day 14, where reduction in locomotor activity and NOR percentage was observed in all groups, with F (1, 7) = 6.940, p < 0.05 and F (1, 7) = 7.152, p < 0.05, respectively. Besides, the MDA level of the JAβ group was significantly lower (p < 0.01) than that of the dPBS group. However, no significant changes in SOD activity were detected among different groups. Significant reduction in plasma CRH level (p < 0.05) and iNOS expression (p < 0.01) in the brain was detected in the JAβ group as compared to the dAβ group. Hence, our current findings suggest that the tropical fruit juice mixture (F8) has the potential to protect the rats from Aβ-induced neurotoxicity in brain hippocampus tissue possibly via its antioxidant properties and the suppression of iNOS expression and CRH production.

Intranasal MMI-0100 Attenuates Aβ1-42- and LPS-Induced Neuroinflammation and Memory Impairments via the MK2 Signaling Pathway.

Background: Accumulating evidence suggests inhibiting neuroinflammation as a potential target in therapeutic or preventive strategies for Alzheimer's disease (AD). MAPK-activated protein kinase II (MK2), downstream kinase of p38 mitogen activated protein kinase (MAPK) p38 MAPK, was unveiled as a promising option for the treatment of AD. Increasing evidence points at MK2 as involved in neuroinflammatory responses. MMI-0100, a cell-penetrating peptide inhibitor of MK2, exhibits anti-inflammatory effects and is in current clinical trials for the treatment of pulmonary fibrosis. Therefore, it is important to understand the actions of MMI-0100 in neuroinflammation.Methods: The mouse memory function was evaluated using novel object recognition (NOR) and object location recognition (OLR) tasks. Brain hippocampus tissue samples were analyzed by quantitative PCR, Western blotting, and immunostaining. Near-infrared fluorescent and confocal microscopy experiments were used to detect the brain uptake and distribution after intranasal MMI-0100 application.Results: Central MMI-0100 was able to ameliorate the memory deficit induced by Aβ1−42 or LPS in novel object and location memory tasks. MMI-0100 suppressed LPS-induced activation of astrocytes and microglia, and dramatically decreased a series of pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β, COX-2, and iNOS via inhibiting phosphorylation of MK2, but not ERK, JNK, and p38 in vivo and in vitro. Importantly, one of the reasons for the failure of macromolecular protein or peptide drugs in the treatment of AD is that they cannot cross the blood–brain barrier. Our data showed that intranasal administration of MMI-0100 significantly ameliorates the memory deficit induced by Aβ1−42 or LPS. Near-infrared fluorescent and confocal microscopy experiment results showed that a strong fluorescent signal, coming from mouse brains, was observed at 2 h after nasal applications of Cy7.5-MMI-0100. However, brains from control mice treated with saline or Cy7.5 alone displayed no significant signal.Conclusions: MMI-0100 attenuates Aβ1−42- and LPS-induced neuroinflammation and memory impairments via the MK2 signaling pathway. Meanwhile, these data suggest that the MMI-0100/MK2 system may provide a new potential target for treatment of AD.

Development of DNA aptamers targeting low-molecular-weight amyloid-β peptide aggregates in vitro.

We have developed a novel functional nucleic acid aptamer to amyloid-β peptide 1-40 (Aβ1-40) and investigated its potential to detect Aβ peptide fragments in neuropathologically confirmed Alzheimer brain hippocampus tissues samples. Our results demonstrate that the aptamer candidate RNV95 could detect tetrameric/pentameric low-molecular-weight Aβ aggregates in autopsy hippocampal tissue from two neuropathologically confirmed Alzheimer disease cases. Although these are preliminary observations, detailed investigations are under way. This is the first demonstration of aptamer-Aβ binding in Alzheimer brain tissues.

Study on protective effect of ketogenic diet against hippocampal neurons of kainic acid-induced epileptic rats

Objective To investigate the protective effects of ketogenic diet on hippocampal neurons of kainic acid (KA)-induced epileptic rats. Methods A total of 40 healthy male specific pathogen free (SPF) Sprague-Dawley (SD) rats were randomly divided into 4 groups, with each group containing 10 rats. Epileptic rat models were formed by injection of KA through lateral ventricle with brain stereotactic instrument. According to Racine classification, epileptic seizures in rats above grade Ⅳ were defined successful. Then the rats were given different dietary treatment: Group C with normal saline and normal diet, Group K with normal saline and ketogenic diet, Group E with KA and normal diet, Group EK with KA and ketogenic diet. All rats were observed for 21 d, and were recorded each body weight. The epileptic seizure frequency and duration were observed at 12:00-15:00 daily. At the 21st day, all rats were put to death, and the brain hippocampus tissues were separated. Neuron injury of rat hippocampal CA3 region in Group E and EK was observed by HE staining. Normal neuron number of rat hippocampal CA3 region in Group E and EK was counted by Nissl staining. Results Group C and K had no epileptic seizures, and the neuron number in hippocampal CA3 region was normal. Rats in both Group E and EK had grade Ⅳ or Ⅴ seizures. The number of seizures in Group EK [(17.90 ± 4.12) times] after 21-day ketogenic diet was decreased significantly compared to Group E [(30.50 ± 4.40) times] after 21-day normal diet ( t = 6.606, P = 0.000). The seizure duration in Group EK [(212.70 ± 17.75) s] after 21-day ketogenic diet was shortened compared to Group E [(335.00 ± 14.21) s] after 21-day normal diet ( t = 17.011, P = 0.000). The normal neuron number in hippocampal CA3 region in Group EK (117.67 ± 7.51) was more than those in Group E (71.33 ± 6.11), with statistically significant difference ( t = 9.614, P = 0.000). Conclusions Ketogenic diet has protective effect on hippocampal neurons of kainic acid-induced epileptic rats. DOI: 10.3969/j.issn.1672-6731.2015.11.011

Brain injury caused by deep hypothermic low-flow cardiopulmonary bypass surgery, an experimental study on piglets

Objective To evaluate the effect and mechanisms of prolonged deep hypothermic low-flow cardiopulmonary bypass (CPB) cardiac surgery to the immature brain on piglets. Methods 15 Beijing Landrace piglets were divided into study group (n=10) and control group (n=5).Routine CPB was established after median thoracotomy in study group under anesthesia.Lowflow CPB(50 ml·kg-1·min-1)was started when the temperature of the animal dropped down to 25 ℃.The aorta was reopened after 120 min cross-clamping.Brain hippocampus tissues were harvested after 120 min following CPB ceased.In control group,hippocampus tissues were harvested after median thoracotomy under anesthesia.In study group,venous blood samples were taken immediately after anesthesia induction (T1),5 min (T2) and 120 min (T3) after the CPB shutdown,and interleukin (IL)-6,tumor necrosis factor (TNF)-α were tested through enzyme-linked immunosorbent assay(ELISA).In both groups,HE staining for pathological examination of brain hippocampus tissues was adopted; and hippocampus tissues homogenates,contents of neuron-specific enolase (NSE),S100 protein β subtypes (S100β) were detected by ELISA method.Results 1 piglet from study group was died by heart arrest after CPB;the other 9 piglets in study group and all 5 in control group completed to the end of the experiment.In study group,compared with T1,IL-6,TNF-α were increased by 7.01％(P＜0.05),3.52％(P＜0.05)in T2,and by 5.10％(P＜0.05),1.47％(P＞0.05)in T3.Compared with control group,study group showed pathological changes of brain damage,and NSE,S100β were also increased by 40.08％(P＜0.05)、29.66％(P＜0.05). Conclusions Deep hypothermic low-flow CPB would result in brain injury on piglets and its key mechanism might be inflammatory injury. Key words: Hypothermic low-flow; Cardiopulmonary bypass; Cardiac surgery; Brain injury; Piglets

Raman signature from brain hippocampus could aid Alzheimer's disease diagnosis

Micro-Raman spectroscopy (MRS) is used for the first time to our knowledge to investigate brain hippocampus tissue from Alzheimer's disease (AD) infected rats. In situ Raman analysis of tissue sections provides distinct spectra useful for distinguishing AD from normal state. The biochemical changes of brain hippocampus tissue including the deposit of beta-amyloid (Abeta) protein, the increase of cholesterol, and hyperphosphorylated tau are observed through MRS when AD occurs. A more convincing multi-Raman criterion based on single Raman peaks, and further in combination with statistical analysis of the entire Raman spectrum, is found capable of classifying brain hippocampus tissues with different pathological features. This study demonstrates the brain hippocampus is an important candidate for considering the early pathological state of AD, and Raman signatures from the brain hippocampus could aid AD diagnosis. In addition, Raman results undoubtedly confirm simultaneous changes of cholesterol and Abeta in the progression of AD.