scholarly journals Isoforsythiaside Attenuates Alzheimer’s Disease via Regulating Mitochondrial Function Through the PI3K/AKT Pathway

2020 ◽  
Vol 21 (16) ◽  
pp. 5687 ◽  
Author(s):  
Chunyue Wang ◽  
Jie Hao ◽  
Xin Liu ◽  
Chenliang Li ◽  
Xuyang Yuan ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Viability ◽  
Mitochondrial Function ◽  
B Cell Lymphoma ◽  
Akt Pathway ◽  
Mitochondrial Apoptosis ◽  
Expression Levels ◽  
The Brain ◽  
Apoptosis Proteins

Improving mitochondrial dysfunction and inhibiting apoptosis has always been regarded as a treatment strategy for Alzheimer’s disease (AD). Isoforsythiaside (IFY), a phenylethanoid glycoside isolated from the dried fruit of Forsythia suspensa, displays antioxidant activity. This study examined the neuroprotective effects of IFY and its underlying mechanisms. In the L-glutamate (L-Glu)-induced apoptosis of HT22 cells, IFY increased cell viability, inhibited mitochondrial apoptosis, and reduced the intracellular levels of reactive oxygen species (ROS), caspase-3, -8 and -9 after 3 h of pretreatment and 12–24 h of co-incubation. In the APPswe/PSEN1dE9 transgenic (APP/PS1) model, IFY reduced the anxiety of mice, improved their memory and cognitive ability, reduced the deposition of beta amyloid (Aβ) plaques in the brain, restrained the phosphorylation of the tau protein to form neurofibrillary tangles, inhibited the level of 4-hydroxynonenal in the brain, and improved phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway-related mitochondrial apoptosis. In Aβ1-42-induced U251 cells, IFY relieved the mitochondrial swelling, crest ruptures and increased their electron density after 3 h of pretreatment and 18–24 h of co-incubation. The improved cell viability and mitochondrial function after IFY incubation was blocked by the synthetic PI3K inhibitor LY294002. Taken together, these results suggest that IFY exerts a protective effect against AD by enhancing the expression levels of anti-apoptosis proteins and reducing the expression levels of pro-apoptosis proteins of B-cell lymphoma-2 (BCL-2) family members though activating the PI3K/AKT pathway.

scholarly journals Protective effects of a natural product, curcumin, against amyloid β induced mitochondrial and synaptic toxicities in Alzheimer's disease

2016 ◽  
Vol 64 (8) ◽  
pp. 1220-1234 ◽  
Author(s):  
P Hemachandra Reddy ◽  
Maria Manczak ◽  
Xiangling Yin ◽  
Mary Catharine Grady ◽  
Andrew Mitchell ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Viability ◽  
Natural Product ◽  
Mitochondrial Biogenesis ◽  
Mitochondrial Function ◽  
Mitochondrial Dynamics ◽  
Amyloid Β ◽  
Synaptic Activity ◽  
Protective Effects

The purpose of our study was to investigate the protective effects of a natural product—‘curcumin’— in Alzheimer's disease (AD)-like neurons. Although much research has been done in AD, very little has been reported on the effects of curcumin on mitochondrial biogenesis, dynamics, function and synaptic activities. Therefore, the present study investigated the protective effects against amyloid β (Aβ) induced mitochondrial and synaptic toxicities. Using human neuroblastoma (SHSY5Y) cells, curcumin and Aβ, we studied the protective effects of curcumin against Aβ. Further, we also studied preventive (curcumin+Aβ) and intervention (Aβ+curcumin) effects of curcumin against Aβ in SHSY5Y cells. Using real time RT-PCR, immunoblotting and immunofluorescence analysis, we measured mRNA and protein levels of mitochondrial dynamics, mitochondrial biogenesis and synaptic genes. We also assessed mitochondrial function by measuring hydrogen peroxide, lipid peroxidation, cytochrome oxidase activity and mitochondrial ATP. Cell viability was studied using the MTT assay. Aβ was found to impair mitochondrial dynamics, reduce mitochondrial biogenesis and decrease synaptic activity and mitochondrial function. In contrast, curcumin enhanced mitochondrial fusion activity and reduced fission machinery, and increased biogenesis and synaptic proteins. Mitochondrial function and cell viability were elevated in curcumin treated cells. Interestingly, curcumin pre- and post-treated cells incubated with Aβ showed reduced mitochondrial dysfunction, and maintained cell viability and mitochondrial dynamics, mitochondrial biogenesis and synaptic activity. Further, the protective effects of curcumin were stronger in pretreated SHSY5Y cells than in post-treated cells, indicating that curcumin works better in prevention than treatment in AD-like neurons. Our findings suggest that curcumin is a promising drug molecule to treat AD patients.

scholarly journals Metformin Ameliorates Aβ Pathology by Insulin-Degrading Enzyme in a Transgenic Mouse Model of Alzheimer’s Disease

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Xin-Yi Lu ◽  
Shun Huang ◽  
Qu-Bo Chen ◽  
Dapeng Zhang ◽  
Wanyan Li ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transgenic Mice ◽  
Mrna Expression ◽  
Insulin Degrading Enzyme ◽  
Antidiabetic Drug ◽  
Degrading Enzyme ◽  
Expression Levels ◽  
The Brain ◽  
Mrna Expression Levels

Alzheimer’s disease (AD) is the most common neurodegenerative disease. The accumulation of amyloid beta (Aβ) is the main pathology of AD. Metformin, a well-known antidiabetic drug, has been reported to have AD-protective effect. However, the mechanism is still unclear. In this study, we tried to figure out whether metformin could activate insulin-degrading enzyme (IDE) to ameliorate Aβ-induced pathology. Morris water maze and Y-maze results indicated that metformin could improve the learning and memory ability in APPswe/PS1dE9 (APP/PS1) transgenic mice. 18F-FDG PET-CT result showed that metformin could ameliorate the neural dysfunction in APP/PS1 transgenic mice. PCR analysis showed that metformin could effectively improve the mRNA expression level of nerve and synapse-related genes (Syp, Ngf, and Bdnf) in the brain. Metformin decreased oxidative stress (malondialdehyde and superoxide dismutase) and neuroinflammation (IL-1β and IL-6) in APP/PS1 mice. In addition, metformin obviously reduced the Aβ level in the brain of APP/PS1 mice. Metformin did not affect the enzyme activities and mRNA expression levels of Aβ-related secretases (ADAM10, BACE1, and PS1). Meanwhile, metformin also did not affect the mRNA expression levels of Aβ-related transporters (LRP1 and RAGE). Metformin increased the protein levels of p-AMPK and IDE in the brain of APP/PS1 mice, which might be the key mechanism of metformin on AD. In conclusion, the well-known antidiabetic drug, metformin, could be a promising drug for AD treatment.

scholarly journals PI3K–AKT Signaling Activation and Icariin: The Potential Effects on the Perimenopausal Depression-Like Rat Model

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3700 ◽  
Author(s):  
Li-Hua Cao ◽  
Jing-Yi Qiao ◽  
Hui-Yuan Huang ◽  
Xiao-Yan Fang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Rat Model ◽  
Significant Risk ◽  
B Cell Lymphoma ◽  
Brain Homogenate ◽  
Serum Levels ◽  
Akt Signaling ◽  
Akt Pathway ◽  
Expression Levels ◽  
Increased Risk ◽  
The Brain

Icariin is a prenylated flavonol glycoside isolated from Epimedium herb, and has been shown to be its main bioactive component. Recently, the antidepressant-like mechanism of icariin has been increasingly evaluated and demonstrated. However, there are few studies that have focused on the involvement of the phosphatidylinositol 3-kinase (PI3K)/serine-threonine protein kinase (AKT) signaling in mediating the perimenopausal depression effects of icariin. Perimenopausal depression is a chronic recurrent disease that leads to an increased risk of suicide, and poses a significant risk to public health. The aim of the present study was to explore the effect of icariin on the expression of the PI3K–AKT pathway related to proteins in a rat model of perimenopausal depression. Eighty percent of the left ovary and the entire right ovary were removed from the model rats. A perimenopausal depression model was created through 18 days of chronic unpredictable stimulation, followed by the gavage administration of target drugs for 30 consecutive days. We found that icariin administered at various doses significantly improved the apparent symptoms in the model rats, increased the organ indices of the uterus, spleen, and thymus, and improved the pathological changes in the ovaries. Moreover, icariin administration elevated the serum levels of female hormone estradiol (E2), testosterone (T), and interleukin (IL)-2, decreased those of follicle stimulating hormone (FSH) and luteotropic hormone (LH), promoted the expression levels of estrogen receptor (ER) and ERα in the hypothalamus, and increased those of serotonin (5-HT), dopamine (DA), and noradrenaline (NA) in the brain homogenate. Furthermore, icariin elevated the expression levels of AKT, phosphorylation-akt (p-AKT), PI3K (110 kDa), PI3K (85 kDa), and B-cell lymphoma 2 (Bcl-2) in the ovaries, and inhibited those of Bax. These results show that icariin administration rebalanced the disordered sex hormones in perimenopausal depression rats, regulated the secretion of neurotransmitters in the brain, boosted immune function, and improved the perimenopausal syndrome. The mechanism of action may be related to the regulation of the expression of PI3K–AKT pathway-related proteins.

scholarly journals Mitochondrial Dysfunction in Alzheimer’s Disease: A Biomarker of the Future?

Biomedicines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 63
Author(s):  
Simon M. Bell ◽  
Katy Barnes ◽  
Matteo De Marco ◽  
Pamela J. Shaw ◽  
Laura Ferraiuolo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mitochondrial Function ◽  
Imaging Techniques ◽  
The Body ◽  
Atp Production ◽  
Disease Modifying Therapies ◽  
Mitochondrial Functions ◽  
Species Production ◽  
The Brain

Alzheimer’s disease (AD) is the most common cause of dementia worldwide and is characterised pathologically by the accumulation of amyloid beta and tau protein aggregates. Currently, there are no approved disease modifying therapies for clearance of either of these proteins from the brain of people with AD. As well as abnormalities in protein aggregation, other pathological changes are seen in this condition. The function of mitochondria in both the nervous system and rest of the body is altered early in this disease, and both amyloid and tau have detrimental effects on mitochondrial function. In this review article, we describe how the function and structure of mitochondria change in AD. This review summarises current imaging techniques that use surrogate markers of mitochondrial function in both research and clinical practice, but also how mitochondrial functions such as ATP production, calcium homeostasis, mitophagy and reactive oxygen species production are affected in AD mitochondria. The evidence reviewed suggests that the measurement of mitochondrial function may be developed into a future biomarker for early AD. Further work with larger cohorts of patients is needed before mitochondrial functional biomarkers are ready for clinical use.

scholarly journals PLCG2 as a Risk Factor for Alzheimer's Disease

2020 ◽  
Author(s):  
Andy Po-Yi Tsai ◽  
Chuanpeng Dong ◽  
Christoph Preuss ◽  
Miguel Moutinho ◽  
Peter Bor-Chian Lin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Missense Variant ◽  
Parahippocampal Gyrus ◽  
Carrier Status ◽  
Eqtl Analysis ◽  
Expression Levels ◽  
Amyloid Pathology ◽  
The Brain

Abstract Background Alzheimer's disease (AD) is characterized by robust microgliosis and phenotypic changes that accompany disease pathogenesis. Indeed, genetic variants in microglial genes are linked to risk for late-onset AD (LOAD). Phospholipase C 𝛾 2 (PLCG2) participates in the transduction of signals emanating from immune cell-surface receptors that regulate the inflammatory response and is selectively expressed by microglia in the brain. A rare variant in PLCG2 (P522R) was previously found to be protective against LOAD. Here, we performed association analysis to identify a new genetic variation in PLCG2 that is associated with elevated risk for LOAD.Methods Using whole genome sequencing (N=1,894) and RNA-Seq (N=1,077) data from the AMP-AD cohort, we investigated whether a missense variant in PLCG2 (M28L) was associated with risk for LOAD. We have examined the homology model and space-filling model of PLCG2 generated with PyMOL to investigate the protein structure of PLCG2 with substitutions of LOAD risk and protective variants in PLCG2 . Gene expression analysis and expression quantitative trait loci (eQTL) of PLCG2 were conducted. We also evaluated the relationship between PLCG2 expression levels and amyloid plaque density and expression levels of microglia specific markers ( AIF1 and TMEM119 ). Age, sex, and APOE ε4 carrier status were used as covariates. Finally, we investigated the longitudinal changes PLCG2 expression in the 5XFAD mouse model of AD and it relationship to amyloid pathology progression.Results A rare missense variant in PLCG2 (M28L) confers increased AD risk ( p =0.047; OR=1.164 [95% CI=1.002-1.351]). PLCG2 is highly expressed in the brain and was significantly up-regulated in the parahippocampal gyrus, superior temporal gyrus, and inferior temporal gyrus in LOAD. Higher PLCG2 expression levels were associated with increased brain amyloid deposition. The findings were validated in 5xFAD mice, showing a disease progression-dependent increase in Plcg2 expression with amyloid pathology. Furthermore, eQTL analysis identified several variants as associated with increased PLCG2 expression levels in the brain and other organs.Conclusions Our results provide further evidence that PLCG2 and the M28L variant confers increase risk for LOAD and may play an important role in AD pathophysiology.

scholarly journals PLCG2 as a Risk Factor for Alzheimer's Disease.

2020 ◽  
Author(s):  
Andy P. Tsai ◽  
Chuanpeng Dong ◽  
Christoph Preuss ◽  
Miguel Moutinho ◽  
Peter Bor-Chian Lin ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Late Onset ◽  
Missense Variant ◽  
Parahippocampal Gyrus ◽  
Carrier Status ◽  
Eqtl Analysis ◽  
Expression Levels ◽  
Amyloid Pathology ◽  
The Brain

Abstract Background Alzheimer's disease (AD) is characterized by robust microgliosis and phenotypic changes that accompany disease pathogenesis. Indeed, genetic variants in microglial genes are linked to risk for late-onset AD (LOAD). Phospholipase C 𝛾 2 (PLCG2) participates in the transduction of signals emanating from immune cell-surface receptors that regulate the inflammatory response and is selectively expressed by microglia in the brain. A rare variant in PLCG2 (P522R) was previously found to be protective against LOAD. Here, we performed association analysis to identify a new genetic variation in PLCG2 that is associated with elevated risk for LOAD. Methods Using whole genome sequencing (N=1,894) and RNA-Seq (N=1,077) data from the AMP-AD cohort, we investigated whether a missense variant in PLCG2 (M28L) was associated with risk for LOAD. We have examined the homology model and space-filling model of PLCG2 generated with PyMOL to investigate the protein structure of PLCG2 with substitutions of LOAD risk and protective variants in PLCG2 . Gene expression analysis and expression quantitative trait loci (eQTL) of PLCG2 were conducted. We also evaluated the relationship between PLCG2 expression levels and amyloid plaque density and expression levels of microglia specific markers ( AIF1 and TMEM119 ). Age, sex, and APOE ε4 carrier status were used as covariates. Finally, we investigated the longitudinal changes PLCG2 expression in the 5XFAD mouse model of AD and it relationship to amyloid pathology progression. Results A rare missense variant in PLCG2 (M28L) confers increased AD risk ( p =0.047; OR=1.164 [95% CI=1.002-1.351]). PLCG2 is highly expressed in the brain and was significantly up-regulated in the parahippocampal gyrus, superior temporal gyrus, and inferior temporal gyrus in LOAD. Higher PLCG2 expression levels were associated with increased brain amyloid deposition. The findings were validated in 5xFAD mice, showing a disease progression-dependent increase in Plcg2 expression with amyloid pathology. Furthermore, eQTL analysis identified several variants as associated with increased PLCG2 expression levels in the brain and other organs. Conclusions Our results provide further evidence that PLCG2 and the M28L variant confers increase risk for LOAD and may play an important role in AD pathophysiology.

scholarly journals Brain CHID1 Expression Correlates with NRGN and CALB1 in Healthy Subjects and AD Patients

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 882
Author(s):  
Paola Castrogiovanni ◽  
Cristina Sanfilippo ◽  
Rosa Imbesi ◽  
Grazia Maugeri ◽  
Debora Lo Furno ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Calcium Binding ◽  
Meta Analysis ◽  
Inverse Correlation ◽  
Brain Regions ◽  
Brain Disorder ◽  
Expression Levels ◽  
Healthy Control ◽  
The Brain

Alzheimer’s disease is a progressive, devastating, and irreversible brain disorder that, day by day, destroys memory skills and social behavior. Despite this, the number of known genes suitable for discriminating between AD patients is insufficient. Among the genes potentially involved in the development of AD, there are the chitinase-like proteins (CLPs) CHI3L1, CHI3L2, and CHID1. The genes of the first two have been extensively investigated while, on the contrary, little information is available on CHID1. In this manuscript, we conducted transcriptome meta-analysis on an extensive sample of brains of healthy control subjects (n = 1849) (NDHC) and brains of AD patients (n = 1170) in order to demonstrate CHID1 involvement. Our analysis revealed an inverse correlation between the brain CHID1 expression levels and the age of NDHC subjects. Significant differences were highlighted comparing CHID1 expression of NDHC subjects and AD patients. Exclusive in AD patients, the CHID1 expression levels were correlated positively to calcium-binding adapter molecule 1 (IBA1) levels. Furthermore, both in NDHC and in AD patient’s brains, the CHID1 expression levels were directly correlated with calbindin 1 (CALB1) and neurogranin (NRGN). According to brain regions, correlation differences were shown between the expression levels of CHID1 in prefrontal, frontal, occipital, cerebellum, temporal, and limbic system. Sex-related differences were only highlighted in NDHC. CHID1 represents a new chitinase potentially involved in the principal processes underlying Alzheimer’s disease.

scholarly journals TRPML1 Participates in the Progression of Alzheimer’s Disease by Regulating the PPARγ/AMPK/Mtor Signalling Pathway

2017 ◽  
Vol 43 (6) ◽  
pp. 2446-2456 ◽  
Author(s):  
Lu Zhang ◽  
Yu Fang ◽  
Xuan Cheng ◽  
Yajun Lian ◽  
Hongliang Xu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Protein Expression ◽  
Cell Viability ◽  
Neuronal Apoptosis ◽  
Signalling Pathway ◽  
Primary Neurons ◽  
Expression Levels ◽  
Related Proteins

Background: TRPML1 is reported to be involved in the pathogenesis of Alzheimer’s disease (AD) by regulating autophagy; however, the underlying mechanism is not completely clear. Methods: We developed an APP/PS1 transgenic animal model that presents with AD. TRPML1 was also overexpressed in these mice. Protein expression levels were determined by Western blot. Morris water maze (MWM) and recognition tasks were performed to characterize cognitive ability. TUNEL assays were analysed for the detection of neuronal apoptosis. Primary neurons were isolated and treated with the vehicle, Aβ1-42 or Aβ1-42 + mTOR activator, as well as infected with the recombinant adenovirus TRPML1 overexpression vector in vitro. Cell viability was measured by the MTS assay, and lysosomal Ca2+ was also measured. Results: In the APP/PS1 transgenic mice, TRPML1 was downregulated, the PPARγ/AMPK signalling pathway was activated, the mTOR/S6K signalling pathway was suppressed, and autophagic lysosome reformation (ALR)-related proteins were upregulated. TRPML1 overexpression or treatment with PPARγ and AMPK inhibitors or an mTOR activator reduced the expression levels of ALR-related proteins, rescued the memory and recognition impairments and attenuated neuronal apoptosis in mice with the APP/PS1 transgenes. In vitro experiments showed that TRPML1 overexpression or treatment with the mTOR activator propranolol attenuated the Aβ1-42-suppressed cell viability and the Aβ1-42-decreased lysosomal [Ca2+] ion concentration in primary neurons. TRPML1 overexpression or treatment with the mTOR activator propranolol also attenuated the Aβ1-42-inhibited mTOR/S6K signalling pathway and the Aβ1-42-induced ALR-related protein expression levels. Conclusion: TRPML1 is involved in the pathogenesis of AD by regulating autophagy at least in part through the PPARγ/AMPK/mTOR signallingpathway.

Cerebral blood flow regulation by nitric oxide in neurological disorders

2009 ◽  
Vol 87 (8) ◽  
pp. 581-594 ◽  
Author(s):  
Noboru Toda ◽  
Kazuhide Ayajiki ◽  
Tomio Okamura
Keyword(s):  
Nitric Oxide ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cell Viability ◽  
No Production ◽  
Pathogenic Factors ◽  
The Central Nervous System ◽  
The Brain

There has been a rapid increase in the amount of information on the physiological and pathophysiological roles of nitric oxide (NO) in the brain. This molecule, which is formed by the constitutive isoforms of NO synthase, endothelial (eNOS) and neuronal (nNOS), plays an obligatory role in the regulation of cerebral blood flow and cell viability and in the protection of nerve cells or fibres against pathogenic factors associated with Alzheimer’s disease, Huntington’s disease, seizures, and migraine. Cerebral blood flow is impaired by decreased formation of NO from endothelial cells, autonomic nitrergic nerves, or brain neurons and also by increased production of reactive oxygen species (ROS). The NO–ROS interaction is an important topic in discussing blood flow and cell viability in the brain. Excessive production of NO by inducible NOS (iNOS) and nNOS in the brain participates in neurotoxicity. Recent studies on brain circulation have provided useful information about the involvement of impaired NO availability or uncontrolled NO production in cerebral pathogenesis, including Alzheimer’s disease, seizures, vascular headaches, and inflammatory disorders. Insight into the role of NO in the brain will contribute to our better understanding of cerebral hemodynamic dysfunction and will aid in developing novel therapeutic measures in diseases of the central nervous system.

Longitudinal Changes in Individual BrainAGE in Healthy Aging, Mild Cognitive Impairment, and Alzheimer’s Disease

GeroPsych ◽  
2012 ◽  
Vol 25 (4) ◽  
pp. 235-245 ◽  
Author(s):  
Katja Franke ◽  
Christian Gaser
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Aging ◽  
Brain Aging ◽  
Elderly Subjects ◽  
Additional Increase ◽  
Longitudinal Changes ◽  
Novel Method ◽  
The Brain

We recently proposed a novel method that aggregates the multidimensional aging pattern across the brain to a single value. This method proved to provide stable and reliable estimates of brain aging – even across different scanners. While investigating longitudinal changes in BrainAGE in about 400 elderly subjects, we discovered that patients with Alzheimer’s disease and subjects who had converted to AD within 3 years showed accelerated brain atrophy by +6 years at baseline. An additional increase in BrainAGE accumulated to a score of about +9 years during follow-up. Accelerated brain aging was related to prospective cognitive decline and disease severity. In conclusion, the BrainAGE framework indicates discrepancies in brain aging and could thus serve as an indicator for cognitive functioning in the future.

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