scholarly journals Protective Effects of Colivelin Against Alzheimer's Disease in a PDAPP Mouse Model

2016 ◽  
Vol 38 (3) ◽  
pp. 1138-1146 ◽  
Author(s):  
Rong Yin ◽  
Kai Yin ◽  
ZhiQiang Guo ◽  
ZhiQiang Zhang ◽  
LiPin Chen ◽  
...  

Background: Alzheimer's disease (AD) is characterized with progressive memory loss and severe cognitive impairments, which affect everyday life and human health in the elderly. It is required that an effective and safe protective reagent against AD should be developed. It has been reported that humanin (HN) exerts neuroprotective effects against AD. In this study, we investigated the effect of a novel and more effective HN derivative, Colivelin (CLN) on AD. Methods: PDAPPV717I transgenic AD model mice (derived from parental C57/BL6 mice) were used in our study as AD model. Morris water maze test was used to test the memory impairment of AD mice and the levels of Aβ40 and Aβ42 were determined by an Elisa assay. We used an Immunohistochemistry and Immunofluorescence staining method to check the GFAP and MAP2 positive cells, and TUNEL to assess the apoptotic cells. Western blot assay was used to check the expression and phosphorylation level of p38. Results: We found that CLN improved the memory impairment induced by AD and reduced the deposit of Aβ40 and Aβ42. CLN also inhibited cell apoptosis and activation of caspase 3 in brain tissues of AD mice. Inflammation in AD mice was alleviated by CLN treatment, including the accumulation of GFAP positive cells and the inflammatory cytokines. With both structure of AGA-HNG and ANDF, CLN exhibited significantly stronger effects than synchronously administration of AGA-HNG and ADNF, suggesting CLN as a novel potential effective therapeutic reagent for AD patients. Finally, we found that CLN inhibited phosphorylation of p38 in AD mice and p38 inhibitor, SB203580 weakened the therapeutic effect of CLN. Conclusion: CLN effectively improved the memory dysfunction in PDAPP mice, and our data suggests CLN as a novel and effective reagent which may have great potentials in AD therapy.

2020 ◽  
Vol 11 (1) ◽  
pp. 391-401
Author(s):  
Jiang Cheng ◽  
Guowei Wang ◽  
Na Zhang ◽  
Fang Li ◽  
Lina Shi ◽  
...  

AbstractBackground:Alzheimer’s disease (AD) is an ultimately fatal, degenerative brain disease in the elderly people. In the current work, we assessed the defensive capability of isovitexin (IVX) through an intracerebroventricular injection of streptozotocin (STZ)-induced AD mouse model.Methods:Mice were separated into four cohorts: sham-operated control mice; STZ-intoxicated Alzheimer’s mice; IVX cohort, IVX + STZ; and Ant-107 cohort, antagomiR-107 + IVX/STZ as in the IVX cohort.Results:The outcomes indicated that IVX administration ameliorated spatial memory loss and blunted a cascade of neuro-noxious episodes – including increased amyloid-beta (Aβ) and degraded myelin basic protein burden, neuroinflammation (represented by elevated caspase-1, TNF-α and IL-6 levels) and autophagic dysfunction (represented by altered LC3-II, Atg7 and beclin-1 expressions) – via the inhibition of PI3K/Akt/mTOR signalling axis. We considered the question of whether the epigenetic role of microRNA-107 (miR-107) has any impact on these events, by using antagomiR-107.Conclusion:This probing underscored that miR-107 could be a pivotal regulatory button in the activation of molecular signals linked with the beneficial autophagic process and anti-inflammatory activities in relation to IVX treatment. Hence, this report exemplifies that IVX could guard against Aβ toxicity and serve as an effectual treatment for patients afflicted with AD.


2011 ◽  
Vol 5 (2) ◽  
pp. 108-113 ◽  
Author(s):  
Maria Niures P.S. Matioli ◽  
Arnaldo Etzel ◽  
João A.G.G. Prats ◽  
Wares F. de O. Medeiros ◽  
Taiguara R. Monteiro ◽  
...  

Abstract Alzheimer's disease (AD) is the most common cause of dementia in the elderly. Efforts to determine risk factors for the development of AD are important for risk stratification and early diagnosis. Furthermore, there are no standardized practices for memory screening. Lack of knowledge on AD, perception of memory loss as part of normal aging, and poor socioeconomic conditions may also be implicated in the current situation of dementia. Objective: To evaluate knowledge of AD in a literate population of elders and correlate these findings with sociodemographic characteristics. Methods: A descriptive survey design study enrolled 994 volunteers from September 2007 to May 2008 in the city of Santos, São Paulo, Brazil, to answer a brief questionnaire consisting of 8 simple questions about knowledge of AD and worries about memory loss. Results: Greater knowledge about AD was associated with eight or more years of education, female gender and age between 60 and 70 years. Also, 52.8% of responders (95% CI - 49.5-56.0%) answered that memory loss is part of normal aging and 77.5% (95% CI - 74.7-80.1%) had never sought a doctor to evaluate their memories. Conclusion: Our study results reinforced that the first line of preventing late diagnosis of dementia is to act in health promotion, especially by targeting subjects older than 70 years of male gender and with lower educational level. It also provided evidence that strategies to promote physician initiative in treating memory problems are also paramount.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Peter Wostyn ◽  
Debby Van Dam ◽  
Kurt Audenaert ◽  
Peter Paul De Deyn

Alzheimer's disease (AD), the most common type of dementia among older people, is characterized by the accumulation of β-amyloid (Aβ) senile plaques and neurofibrillary tangles composed of hyperphosphorylated tau in the brain. Despite major advances in understanding the molecular etiology of the disease, progress in the clinical treatment of AD patients has been extremely limited. Therefore, new and more effective therapeutic approaches are needed. Accumulating evidence from human and animal studies suggests that the long-term consumption of caffeine, the most commonly used psychoactive drug in the world, may be protective against AD. The mechanisms underlying the suggested beneficial effect of caffeine against AD remain to be elucidated. In recent studies, several potential neuroprotective effects of caffeine have been proposed. Interestingly, a recent study in rats showed that the long-term consumption of caffeine increased cerebrospinal fluid (CSF) production, associated with the increased expression of Na+-K+ATPase and increased cerebral blood flow. Compromised function of the choroid plexus and defective CSF production and turnover, with diminished clearance of Aβ, may be one mechanism implicated in the pathogenesis of late-onset AD. If reduced CSF turnover is a risk factor for AD, then therapeutic strategies to improve CSF flow are reasonable. In this paper, we hypothesize that long-term caffeine consumption could exert protective effects against AD at least in part by facilitating CSF production, turnover, and clearance. Further, we propose a preclinical experimental design allowing evaluation of this hypothesis.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Dongdong Zhang ◽  
Zhe Wang ◽  
Chenxia Sheng ◽  
Weijun Peng ◽  
Shan Hui ◽  
...  

Icariin is a prenylated flavonol glycoside derived from the Chinese herbEpimedium sagittatumthat exerts a variety of pharmacological activities and shows promise in the treatment and prevention of Alzheimer’s disease. In this study, we investigated the neuroprotective effects of icariin against amyloid beta protein fragment 25–35 (Aβ25–35) induced neurotoxicity in cultured rat pheochromocytoma PC12 cells and explored potential underlying mechanisms. Our results showed that icariin dose-dependently increased cell viability and decreasedAβ25–35-induced apoptosis, as assessed by MTT assay and Annexin V/propidium iodide staining, respectively. Results of western blot analysis revealed that the selective phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 suppressed icariin-induced Akt phosphorylation, suggesting that the protective effects of icariin are associated with activation of the PI3K/Akt signaling pathway. LY294002 also blocked the icariin-induced downregulation of proapoptotic factors Bax and caspase-3 and upregulation of antiapoptotic factor Bcl-2 inAβ25–35-treated PC12 cells. These findings provide further evidence for the clinical efficacy of icariin in the treatment of Alzheimer’s disease.


Author(s):  
Xiao- Bei Zhang ◽  
Jintao Li ◽  
Juanhua Gu ◽  
Yue-Qin Zeng

: Alzheimer’s disease (AD) is one of the most common neurodegenerative diseases with chronic, progressive, and irreversible characteristics, affecting nearly 50 million older adults worldwide. The pathogenesis of AD includes the formation of senile plaques, the abnormal aggregation of tau protein and the gradual degeneration and death of cerebral cortical cells. The main symptoms are memory loss, cognitive decline and behavioral disorders. Studies indicate that cannabidiol(CBD) possesses various pharmacological activities including anti-inflammatory, anti-oxidation and neuroprotective activities. It has been suggested as a potential multi-target medicine for treatment of AD. In this review, we aim to summarize the underlying mechanisms and protective effects of CBD on signaling pathways and central receptors involved in the pathogenesis of AD, including the endocannabinoid system(eCBs), the Transient receptor potential vanilloid type 1(TRPV1) receptor, and the Peroxisome proliferator-activated receptor (PPAR) receptor.


2020 ◽  
Vol 8 (2) ◽  
pp. 199 ◽  
Author(s):  
V. Prakash Reddy ◽  
Puspa Aryal ◽  
Sara Robinson ◽  
Raheemat Rafiu ◽  
Mark Obrenovich ◽  
...  

Polyphenolic antioxidants, including dietary plant lignans, modulate the gut–brain axis, which involves transformation of these polyphenolic compounds into physiologically active and neuroprotector compounds (called human lignans) through gut bacterial metabolism. These gut bacterial metabolites exert their neuroprotective effects in various neurodegenerative diseases, such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), and also have protective effects against other diseases, such as cardiovascular diseases, cancer, and diabetes. For example, enterolactone and enterodiol, the therapeutically relevant polyphenols, are formed as the secondary gut bacterial metabolites of lignans, the non-flavonoid polyphenolic compounds found in plant-based foods. These compounds are also acetylcholinesterase inhibitors, and thereby have potential applications as therapeutics in AD and other neurological diseases. Polyphenols are also advanced glycation end product (AGE) inhibitors (antiglycating agents), and thereby exert neuroprotective effects in cases of AD. Thus, gut bacterial metabolism of lignans and other dietary polyphenolic compounds results in the formation of neuroprotective polyphenols—some of which have enhanced blood–brain barrier permeability. It is hypothesized that gut bacterial metabolism-derived polyphenols, when combined with the nanoparticle-based blood–brain barrier (BBB)-targeted drug delivery, may prove to be effective therapeutics for various neurological disorders, including traumatic brain injury (TBI), AD, and PD. This mini-review addresses the role of polyphenolic compounds in the gut–brain axis, focusing on AD.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Chunyue Wang ◽  
Xueying Cai ◽  
Ruochen Wang ◽  
Siyu Zhai ◽  
Yongfeng Zhang ◽  
...  

Abstract Background Endoplasmic reticulum (ER) stress is involved in the progression of Alzheimer’s disease (AD). Verbascoside (VB), an active phenylethanoid glycoside that was first isolated from Verbascum sinuatum (the wavyleaf mullein), possesses anti-inflammatory, antioxidative, and anti-apoptotic effects. The purpose of this study was to elucidate the beneficial effects of VB in amyloid β (Aβ)1–42-damaged human glioma (U251) cells and in APPswe/PSEN1dE9 transgenic (APP/PS1) mice. Methods U251 cells were co-incubated with 10 μM of Aβ1-42 and treated with VB. The protective effects of VB were investigated by using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide assay, flow cytometry, fluorescence staining, and transmission electron microscopy. APP/PS1 transgenic mice were treated for 6 weeks with VB. Learning and memory were evaluated using a Morris water maze test. Immunohistochemistry, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling, thioflavin-S staining, and proteomics analysis were performed to study the potential neuroprotective mechanism. Enzyme-linked immunosorbent assays and western blot were performed to analyze altered protein levels of brain lysates in APP/PS1 mice and/or Aβ1-42-damaged U251 cells. Results In Aβ1-42-damaged U251 cells, VB significantly improved cell viability, inhibited apoptosis, reduced calcium accumulation and the intracellular concentrations of reactive oxygen species, and improved the morphology of mitochondria and ER. In APP/PS1 mice, 6-week administration of VB significantly improved memory and cognition. VB inhibited apoptosis, reduced the deposition of Aβ, reduced the formation of neurofibrillary tangles formed by hyperphosphorylated tau protein, and downregulated the expression levels of 4-hydroxynonenal and mesencephalic astrocyte-derived neurotrophic factor in the brains of APP/PS1 mice. Proteomics analysis of mouse hippocampus suggested that the neuroprotective effect of VB may be related to the reduction of ER stress. This was indicated by the fact that VB inhibited the three branches of the unfolded protein response, thereby attenuating ER stress and preventing apoptosis. Conclusions The results confirmed that VB possesses significant neuroprotective effects, which are related to the reduction of ER stress. These findings support the status of VB as a potentially effective treatment for AD and warrant further research.


2020 ◽  
Vol 6 (33) ◽  
pp. eabb9036
Author(s):  
Bradlee L. Heckmann ◽  
Brett J. W. Teubner ◽  
Emilio Boada-Romero ◽  
Bart Tummers ◽  
Clifford Guy ◽  
...  

Noncanonical functions of autophagy proteins have been implicated in neurodegenerative conditions, including Alzheimer’s disease (AD). The WD domain of the autophagy protein Atg16L is dispensable for canonical autophagy but required for its noncanonical functions. Two-year-old mice lacking this domain presented with robust β-amyloid (Aβ) pathology, tau hyperphosphorylation, reactive microgliosis, pervasive neurodegeneration, and severe behavioral and memory deficiencies, consistent with human disease. Mechanistically, we found this WD domain was required for the recycling of Aβ receptors in primary microglia. Pharmacologic suppression of neuroinflammation reversed established memory impairment and markers of disease pathology in this novel AD model. Therefore, loss of the Atg16L WD domain drives spontaneous AD in mice, and inhibition of neuroinflammation is a potential therapeutic approach for treating neurodegeneration and memory loss. A decline in expression of ATG16L in the brains of human patients with AD suggests the possibility that a similar mechanism may contribute in human disease.


2016 ◽  
Vol 27 (1) ◽  
pp. 61-70 ◽  
Author(s):  
Chenhui Ji ◽  
Guo-Fang Xue ◽  
Guanglai Li ◽  
Dongfang Li ◽  
Christian Hölscher

AbstractGlucose-dependent insulinotropic polypeptide (GIP) is a member of the incretin hormones and growth factors. Neurons express the GIP receptor, and GIP and its agonists can pass through the blood brain barrier and show remarkable neuroprotective effects by protecting synapse function and numbers, promoting neuronal proliferation, reducing amyloid plaques in the cortex and reducing the chronic inflammation response of the nervous system. Long-acting analogues of GIP that are protease resistant had been developed as a treatment for type 2 diabetes. It has been found that such GIP analogues show good protective effects in animal models of Alzheimer’s disease. Novel dual agonist peptides that activate the GIP receptor and another incretin receptor, glucagon-like peptide -1 (GLP-1), are under development that show superior effects in diabetic patients compared to single GLP-1 agonists. The dual agonists also show great promise in treating neurodegenerative disorders, and there are currently several clinical trials ongoing, testing GLP-1 mimetics in people with Alzheimer’s or Parkinson’s disease.


2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Kexin Wang ◽  
Hongyan Li ◽  
Hongxing Wang ◽  
Jun-hui Wang ◽  
Feng Song ◽  
...  

Neurons suffer detrimental effects from β-amyloid toxicity in Alzheimer’s disease. The exercise hormone, irisin, is found to induce a neuroprotective gene program and facilitates the beneficial effects on cognitive function. But no effort is made to test its direct protective effects on neurons against the Aβ-induced cell toxicity so far. In the present study, we investigated whether irisin could protect neurons against Aβ- (25–35) induced cell damage and explored the possible underlying mechanisms. Primary cell cultures of astrocytes and neurons were established. Conditioned medium from astrocyte was collected for the treatment and biochemistry assay study. To explore the protein expression changes, Western blot and ELISA assays were used in these in vitro cell culture models. Exposure of hippocampal neurons to 10 μM Aβ (25–35) caused significant reduction on cell viability, and the toxic effect was not significantly reduced by the coadministration of irisin. However, pretreated astrocyte-conditioned medium with irisin for 12 hours notably protected the neurons from the toxicity of Aβ. Also, we found that irisin could attenuate the release of IL-6 and IL-1β from cultured astrocytes and decrease the expression level of COX-2 and phosphorylation of AKT. Last, we found that irisin could reduce NFκB activation in astrocyte exposed to Aβ by preventing the phosphorylation and the loss of IκBα. Our finding may provide novel evidence for the future application of irisin in the treatment of Alzheimer’s disease and the memory dysfunction in diabetes mellitus.


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