Mechanism of ellagic acid improving cognitive dysfunction in APP/PS double transgenic mice based on PI3K/AKT/GSK-3β signaling pathway / 中国药理学通报

Aim To investigate the effect of ellagic acid (EA) on cognitive function in APP/PS 1 double- transgenic mice, and to explore the regulatory mechanism of ellagic acid on the level of oxidative stress in the hippocampus of double-transgenic mice based on the phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase-3 (PI3K/AKT/GSK-3 β) signaling pathway. Methods Thirty-two SPF-grade 6-month-old APP/PS 1 double transgenic mice were randomly divided into four groups, namely, APP/PS 1 group, APP/PS1 + EA group, APP/PS1 + LY294002 group, APP/PS 1 + EA + LY294002 group, with eight mice in each group, and eight SPF-grade C57BL/6J wild type mice ( Wild type) were selected as the blank control group. The APP/PS 1 + EA group was given 50 mg · kg

[Galangin alleviates learning and memory impairments in APP/PS1 double- transgenic mice by regulating Akt/MEF2D/Beclin-1 signaling pathway].

The study aimed to investigate the effects of galangin on learning and memory impairments and Akt/MEF2 D/Beclin-1 signaling pathway in APP/PS1 double-transgenic mice. The mice in this experiment were divided into the normal group, model group, low-(25 mg·kg~(-1)), medium-(50 mg·kg~(-1)), and high-dose(100 mg·kg~(-1)) galangin groups, donepezil(3 mg·kg~(-1)) group, Akt inhibitor(25 mg·kg~(-1)) group, and autophagy inhibitor(30 mg·kg~(-1)) group, with ten in each group, and administered with the corresponding drugs for 30 successive days. On the 24 th day of medication, the water maze and dark avoidance tests were performed. The levels of p-tau, ß-amyloid peptide 1-42(Aß_(42)), acetylcholinesterase(AChE), ß-site amyloid precursor protein cleaving enzyme 1(BACE1), and amyloid precursor protein(APP) in hippocampus were detected by ELISA, the Beclin-1 mRNA expression by RT-PCR, the expression of Aß_(42) and glial fibrillary acidic protein(GFAP) by immunohistochemistry, and the expression of myocyte enhancer factor 2 D(MEF2 D) by immunofluorescence assay. The pathological changes in hippocampus were observed after HE staining, and the expression of Akt, MEF2 D, and Beclin-1 in hippocampus were assayed by Western blot. These results showed that compared with the normal group, the model group exhibited prolonged swimming time, increased number of errors and electric shocks, up-regulated p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened incubation period, decreased p-Akt and MEF2 D, and obvious hippocampal injury. Compared with the model group, donepezil and galangin shortened the swimming time, reduced the number of errors and electric shocks, down-regulated the expression of p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, prolonged the incubation period, up-regulated p-Akt and MEF2 D, and improved the pathological changes in hippocampus. Compared with the autophagy inhibitor group, galangin prolonged the swimming time, elevated the number of errors and electric shocks, enhanced the expression of p-tau, Aß_(42), APP, AChE, BACE1, GFAP, and Beclin-1, shortened the incubation period, and diminished the expression of p-Akt and MEF2 D. In conclusion, galangin improves the learning and memory impairments and hippocampal neuron injury of APP/PS1 mice, which may be related to its regulation of Akt/MEF2 D/Beclin-1 signaling pathway.

Effect of Gastrodiae Rhizoma Powder on Prevention of Dementia and Oxidation Resistance in Mice / 中国实验方剂学杂志

Objective::To study whether long-term administration of Gastrodiae Rhizoma powder can improve the learning and memory ability of APPswe/PSldE9 double transgenic (APP/PS1) Alzheimer' s disease(AD) model mice and delay the progress of AD whether these effects are related to the regulation of antioxidant stress pathway in Kelch-like epoxylopropylamine-related protein 1(Keap1)-nuclear factor E2 related factor 2 (Nrf2)/heme oxygenase(HO)-1, and further explore the neuroprotective mechanism of Gastrodiae Rhizoma powder and its role in the prevention and treatment of AD. Method::APP/PS1 double transgenic mice model, the mice consisted of five groups: normal, normal administration group, model group, Gastrodiae Rhizoma powder prevention group, Gastrodiae Rhizoma powder treatment group.The mice in the normal administration group and the Gastrodiae Rhizoma powder prevention group were given the same dose of Gastrodiae Rhizoma powder (1.5 g·kg-1) daily at the age of 8 weeks.The normal group and model group were given the same amount of normal saline at the same time, until 24 weeks old, Morris water maze was used to test the learning and memory ability of mice, and the treatment group was treated with Gastrodiae Rhizoma powder at 22 weeks old.The mice were given the same dose of Gastrodiae Rhizoma powder (1.5 g·kg-1) every day for 2 weeks.The number of crossing platform, escape latency and platform residence time of mice were detected by Morris water maze from 24 weeks old to 24 weeks old.RNA, Real-time PCR was extracted from mouse hippocampus to detect the mRNA level of Nrf2, HO-1, Keap1, and Western blot was used to detect the expression of Nrf2, HO-1, Keap1 protein in mouse hippocampus. Result::Compared with normal group, the water maze test showed that the learning and memory ability of model group was lower than that of the model group (P<0.01), and the learning and memory ability of Gastrodiae Rhizoma powder prevention group and Gastrodiae Rhizoma powder treatment group was significantly higher than that of model group (P<0.01). Compared with normal group, the levels of Nrf2, HO-1 and protein in the hippocampus in model group decreased in varying degrees (P<0.05). Compared with model group, Gastrodiae Rhizoma powder prevented Nrf2, in the hippocampus of mice in model group.The level of HO-1 in mRNA and protein increased in different degrees (P<0.05, P<0.01). Levels of Nrf2, HO-1 mRNA in Gastrodiae Rhizoma powder treatment group was significantly higher than that in Gastrodiae Rhizoma powder group (P<0.05). There was no significant difference in the expression of Nrf2, HO-1 protein.There was no significant difference in mRNA and protein levels of Keap1 among different groups. Conclusion::Morris water maze test and other results showed that Gastrodiae Rhizoma powder could improve the learning and memory ability of APP/PS1 mice, and it may enhance the expression of downstream antioxidant genes by regulating Keap1-Nrf2/HO-1 pathway.And then improve the learning and memory ability of APP/PS1 mice.

Exposure to fluoride aggravates the impairment in learning and memory and neuropathological lesions in mice carrying the APP/PS1 double-transgenic mutation.

BACKGROUND: Alzheimer's disease (AD) is responsible for 60-70% of all cases of dementia. On the other hand, the tap water consumed by hundreds of millions of people has been fluoridated to prevent tooth decay. However, little is known about the influence of fluoride on the expression of APP and subsequent changes in learning and memory and neuropathological injury. Our aim here was to determine whether exposure to fluoride aggravates the neuropathological lesions in mice carrying the amyloid precursor protein (APP)/presenilin1 (PS1) double mutation. METHODS: These transgenic or wide-type (WT) mice received 0.3 ml of a solution of fluoride (0.1 or 1 mg/ml, prepared with NaF) by intragastric administration once each day for 12 weeks. The learning and memory of these animals were assessed with the Morris water maze test. Senile plaques, ionized calcium binding adaptor molecule 1 (Iba-1), and complement component 3 (C3) expression were semi-quantified by immunohistochemical staining; the level of Aß42 was detected by Aß42 enzyme-linked immunosorbent assays (ELISAs); the levels of synaptic proteins and enzymes that cleave APP determined by Western blotting; and the malondialdehyde (MDA) content and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) measured by biochemical procedures. RESULTS: The untreated APP mice exhibited a decline in learning and memory after 12 weeks of fluoride treatment, whereas treatment of these some animals with low or high levels of fluoride led to such declines after only 4 or 8 weeks, respectively. Exposure of APP mice to fluoride elevated the number of senile plaques and level of Aß42, Iba-1, and BACE1, while reducing the level of ADAM10 in their brains. The lower levels of synaptic proteins and enhanced oxidative stress detected in the hippocampus of APP mice were aggravated to fluoride. CONCLUSIONS: These findings indicate that exposure to fluoride, even at lower concentration, can aggravate the deficit in learning and memory and neuropathological lesions of the mice that express the high level of APP.

[Effect of ßsheet blocking peptide H102 on APP metabolic enzymes in hippocampal brain of double transgenic AD mice].

OBJECTIVE: To investigate the effect of ß-sheet breaker peptide H102 on APP associated secretase in the hippocampus brain regions of APP/PS1 double transgenic mice(AD mice). METHODS: Thirty 6-month-old APP/PS1 double transgenic mice were randomly divided into AD group and H102 group, a group of C57BL/6J mice with the same age, number and background was set as controls(n=15). H102 (5.8 mg/kg) 5 µl was infused by intranasal administration to mice in H102 treatment group, and equal volume of blank solution of H102 was given to mice in control group and AD group. The ability of spatial reference memory was tested by Morris water maze after 30 days of treatment. And then immunohistochemistry tests and Western blot were used to detect the content of α-secretase (ADAM10, ADAM17), ß-secretase (BACE1), γ-secretase (PS1, APH1a, PEN2) in the hippocampus brain regions. RESULTS: Compared with the control group, the expression of BACE1, PS1, PEN-2 and APH1-a protein in the hippocampus of AD group were significantly increased, ADAM10, ADAM17 protein expression were significantly reduced (P<0.05); Compared with the model group, H102 could significantly improve the spatial learning and memory ability of AD mice, significantly decreased the expression of BACE1, PS1, PEN-2 and APH1-a protein in the hippocampus, significantly increased the expression of ADAM10 and ADAM17 protein(P<0.05). CONCLUSIONS: ß sheet peptides blocked H102 can reduce the formation of Aß in the hippocampus brain area, improve the activity of α-secretase in the hippocampus brain region, decrease the activity of ß-and γ-secretase, improve the learning and memory ability of AD mice.

Effect of FSD-C10 on modulation of inflammatory microenvironment in an Alzheimer disease double transgenic mouse model / 中国病理生理杂志

AIM:To explore the therapeutic effect of a novel Rho kinase inhibitor FSD-C10 onβ-amyloid pro-tein precursor (APP)/presenilin-1 (PS1) double transgenic mice.METHODS: The transgenic mice overexpressing hu-man APP with the Swedish mutation (695) and human PS1 with ΔE9 mutation at the age of 8 months were used in this study.The mice were randomly divided into model group and FSD-C10 intervention group, and wild-type mice at the same age served as normal controls .The mice in FSD-C10 intervention group were treated with FSD-C10 (25 mg· kg-1 · d-1 ) for 2 months by intraperitoneal injection .The mice in model group and the wild-type mice were injected with saline in the similar manner.Morris water maze (MWM) test was applied to examine the capacity of learning and memory .The Aβ1-42 deposition, Tau protein phosphorylation , and the expression of β-site APP-cleaving enzyme ( BACE) as well as inflammato-ry molecules, such as TLR-4 and NF-Κb, and M1/M2 microglial markers, such as Inos and Arg-1, were determined by the methods of immunohistochemistry and Western blot .RESULTS: Compared with model group , FSD-C10 significantly improved the learning and memory abilities of APP/PS1 double transgenic mice , accompanied by reduced Aβ1-42 deposi-tion, Tau protein phosphorylation and BACE expression in the hippocampus .The intervention of FSD-C10 decreased the protein levels of TLR-4 and p-NF-Κb, reduced the expression of Inos and increased the expression of Arg-1 in the brain tissues.CONCLUSION:The novel Rho kinase inhibitor FSD-C10 improves the capacity of spatial learning and memory in APP/PS1 double transgenic mice , which may be related to the inhibition of TLRs/NF-Κb signaling pathway , the reduction of the secretion of inflammatory molecules and the polarization of anti-inflammatory M2 microglia, thus improving the in-flammatory microenvironment of the brain in APP/PS1 double transgenic mice .

Effect of FSD-C10 on modulation of inflammatory microenvironment in an Alzheimer disease double transgenic mouse model / 中国病理生理杂志

AIM:To explore the therapeutic effect of a novel Rho kinase inhibitor FSD-C10 onβ-amyloid pro-tein precursor (APP)/presenilin-1 (PS1) double transgenic mice.METHODS: The transgenic mice overexpressing hu-man APP with the Swedish mutation (695) and human PS1 with ΔE9 mutation at the age of 8 months were used in this study.The mice were randomly divided into model group and FSD-C10 intervention group, and wild-type mice at the same age served as normal controls .The mice in FSD-C10 intervention group were treated with FSD-C10 (25 mg· kg-1 · d-1 ) for 2 months by intraperitoneal injection .The mice in model group and the wild-type mice were injected with saline in the similar manner.Morris water maze (MWM) test was applied to examine the capacity of learning and memory .The Aβ1-42 deposition, Tau protein phosphorylation , and the expression of β-site APP-cleaving enzyme ( BACE) as well as inflammato-ry molecules, such as TLR-4 and NF-Κb, and M1/M2 microglial markers, such as Inos and Arg-1, were determined by the methods of immunohistochemistry and Western blot .RESULTS: Compared with model group , FSD-C10 significantly improved the learning and memory abilities of APP/PS1 double transgenic mice , accompanied by reduced Aβ1-42 deposi-tion, Tau protein phosphorylation and BACE expression in the hippocampus .The intervention of FSD-C10 decreased the protein levels of TLR-4 and p-NF-Κb, reduced the expression of Inos and increased the expression of Arg-1 in the brain tissues.CONCLUSION:The novel Rho kinase inhibitor FSD-C10 improves the capacity of spatial learning and memory in APP/PS1 double transgenic mice , which may be related to the inhibition of TLRs/NF-Κb signaling pathway , the reduction of the secretion of inflammatory molecules and the polarization of anti-inflammatory M2 microglia, thus improving the in-flammatory microenvironment of the brain in APP/PS1 double transgenic mice .

Analysis on Effect and Mechanism of Bu-Yang Huan-Wu Decoction of Alzheimer's Disease Mice / 世界科学技术-中医药现代化

This study was aimed to investigate the effects of Bu-Yang Huan-Wu (BYHW) decoction to the learning and memory ability of APP/PS1 double transgenic mice through two behavior tests,in order to observe the Alzheimer's disease (AD) treatment effect of BYHW decoction.A total of 60 APP/PS1 double transgenic mice were randomly divided into five groups,which were the model group,the hydrochloride group,the high-,middle-,and low-dose BYHW decoction group,with ten rats in each group.The C57BL/6J mice were used as the control group.After 30 days of drug administration,all mice were subjected to behavior tests,including new object recognition experiment and step-through task.Western blot was used to detect changes of inflammatory factors,including IL-6 and TNF-α,in hippocampus of mice.The results showed that compared with the model group,the high-and middle-dose BYHW decoction can significantly decrease inflammatory factors of IL-6 and TNF-α expression in hippocampus of APP/PS1 mice.It can also obviously improve the learning and memory ability of APP/PS1 mice.It was concluded that BYHW decoction can significantly decrease the inflammatory factor expression in APP/PS 1 double transgenic AD model mice.It can obviously improve its learning and memory ability,which can be used in the treatment of AD.

[Effects of ß-sheet breaker peptide H102 on synaptic plasticity associated proteins in double transgenic AD mice].

OBJECTIVE: To investigate the effects ofß-sheet breaker peptide H102 on expression of synaptic plasticity associated proteins and learning and memory functions in double transgenic Alzheimer's disease(AD) mice,and to discuss its mechanisms. METHODS: Thirty APP-swe/PS1dE9 double transgenic male mice of 8 weeks were randomly divided into model group and H102 treatment group (15 mice per group). In addition,a group of C57BL/6J mice with the same age and background was set as normal. H102 (5.8 mg/kg) 5 µl was infused by in-tranasal administration to mice in H102 treatment group,and equal volume of blank solution of H102 (chitosan,BSA) was given to mice in con-trol group and model group. The ability of spatial reference memory was tested by Morris Water Maze after 16 weeks treatment,then immunohis-tochemistry tests and Western blot technique were used to detect the content ofß-amyloid peptide(Aß1-42) protein and phospho protein kinase C α、ß2、γ(p-PKCα, p-PKCß2, p-PKCγ), phospho-N-methyl-D-aspartate receptor1(p-NMDAR1), phospho-Calcium/Calmodulin dependent pro-tein kinaseⅡα(p-CaMKⅡα) and phospho-cAMP response element binding protein(p-CREB) of synaptic plasticity associated proteins in mice brain. RESULTS: The ability of learning and memory was significantly improved in H102 treatment group than that in model group by the test of Morris Water Maze. The contents of Aß1-42 proteins and p-PKCα, p-PKCß2, p-PKCγ, p-NMDAR1, p-CaMKⅡαand p-CREB of synaptic plas-ticity associated proteins in mice brain were improved significantly in H102 treatment group than those in model group by the test of immunohis-tochemistry tests and Western blot technique. CONCLUSIONS: ß-sheet breaker peptide H102 can significantly improve synaptic plasticity and the ability of learning and memory in double transgenic AD mice.

Effects of Abnormal Phlegmatic Temperament Granules on Behavioristics and Hippocampus Pathomorphism of APP/PS1 Transgenic Mice / 中国中医药信息杂志

Objective To investigate the effects of Abnormal Phlegmatic Temperament Granules on spatial learning and memory, histopathology morphological change in hippocampus CA1 zone; To discuss its mechanism of action.Methods Three-month-old APP/PS1 transgenic mice were randomly divided into 5 groups: model control group, positive control (donepezil 0.92 mg/kg) group, Abnormal Phlegmatic Temperament Granules high-, medium-, and low-dose groups (3, 2, 1.5 g/kg), 18 mice in each group. Another 18 three-month-old C57BL/ 6J mice were chosen as normal control group. All administration groups received relevant medicine for successive 6 months. Then the changes in learning and memory ability of mice were detected by Morris water maze test; pathomorphism in hippocampus CA1 zone was detected by HE staining method; changes of myelin sheath, microtubule, and microfilament in myelinated nerve of hippocampus CA1 zone were detected by electron microscope. Results Morris water maze test results showed that escape incubation period of APP/PS1 transgenic mice was significantly longer than the normal control group (P<0.01), and the original platform time was significantly shorter than normal control group (P<0.01); compared with model control group, Abnormal Phlegmatic Temperament Granules treatment groups escape latency time was significantly reduced (P<0.05, P<0.01). Space experiments and escape incubation period of Abnormal Phlegmatic Temperament Granules high-, medium-, low-dose groups were significantly shortened (P<0.05, P<0.01), and spatial searching test showed that the times of mice in Abnormal Phlegmatic Temperament Granules high-, medium-, low-dose groups passing through effective area increased (P<0.01). The integrity of HE staining pyramidal cell layer in the hippocampus CA1 zones of Abnormal Phlegmatic Temperament Granules high-, medium-, and low-dose groups was relatively good; cells arranged orderly; distribution was normal. Electron microscopic observation showed that compared with model control group, the hippocampus neurons nuclear had irregular shape; nuclear membrane was clear and complete; chromatin was clear; nucleolus was obvious; cell matrix was uniform; organelles were abundant; mitochondrial cristae was obvious; endoplasmic reticulum and free ribosomes were obvious. Conclusion Abnormal Phlegmatic Temperament Granules can improve spatial learning and memory in APP/PS1 mice, alleviate neuronal ultrastructure damage and ultimately improve cognitive function.

Neuroprotective effect of astrocyte protein phosphatase 2 A up-regulation on APP/PS1 double transgenic mice / 中国病理生理杂志

AIM:To investigate the protective effects of astrocyte protein phosphatase 2A (PP2A) up-regula-tion on APP/PS1 double transgenic mice.METHODS:An eGFP-wtPP2A lentivirus with glial fiber acidic protein promoter was constructed to specifically increase PP2A expression in the astrocytes.The mice were divided into wild -type mice +vector virus group (Con), APP/PS1 transgenic mice +vector virus group (APP/PS1) and APP/PS1 transgenic mice +eGFP-wtPP2A lentivirus group (PP2A) by lateral ventricular injection of the lentivirus.Four weeks after injection of the vi-rus, the immunofluorescence of brain slices were used to detect the level of β-amyloid protein ( Aβ) .Golgi staining was used to detect the changes of dendritic spine density and morphology.Electron microscopy was applied to detect the thickness of postsynaptic density (PSD).The Morris water maze test was applied to examine the learning and memory abilities of the mice.RESULTS: Up-regulation of PP2A in the astrocytes attenuated Aβlevel increasing in APP/PS1 group.Up-regulation of PP2A in the astrocytes significantly attenuated both decreases in the dendritic spine density and the percentage of mushroom-like dendritic spines in the hippocampal CA3 region of APP/PS1 mice.Up-regulation of PP2A in the astrocytes significantly attenuated the reduced thickness of PSD in APP/PS1 group.Up-regulation of PP2A in the astro-cytes attenuated the escape latency extending in APP/PS1 group .CONCLUSION: Up-regulation of PP2A in the astro-cytes reduces AD-like pathological changes, and attenuates synaptic impairment, synaptic plasticity deficits and cognitive impairment in the APP/PS1 double transgenic mice.