scholarly journals Increased Cerebrospinal Fluid Production as a Possible Mechanism Underlying Caffeine's Protective Effect against Alzheimer's Disease

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.

2011 ◽  
Vol 5 ◽  
pp. PMC.S6509 ◽  
Author(s):  
Peter Wostyn ◽  
Kurt Audenaert ◽  
Peter Paul De Deyn

Alzheimer's disease is known to be the most common form of dementia in the elderly. It is clinically characterized by impairment of cognitive functions, as well as changes in personality, behavioral disturbances and an impaired ability to perform activities of daily living. To date, there are no effective ways to cure or reverse the disease. Genetic studies of early-onset familial Alzheimer's disease cases revealed causative mutations in the genes encoding β-amyloid precursor protein and the γ-secretase-complex components presenilin-1 and presenilin-2, supporting an important role of β-amyloid in the pathogenesis of Alzheimer's disease. Compromised function of the choroid plexus and defective cerebrospinal fluid production and turnover, with diminished clearance of β-amyloid, may play an important role in late-onset forms of Alzheimer's disease. If reduced cerebrospinal fluid turnover is a risk factor for Alzheimer's disease, then therapeutic strategies to improve cerebrospinal fluid flow are reasonable. However, the role of deficient cerebrospinal fluid dynamics in Alzheimer's disease and the relevance of choroidal proteins as potential therapeutic targets to enhance cerebrospinal fluid turnover have received relatively little research attention. In this paper, we discuss several choroidal proteins, such as Na+-K+ ATPase, carbonic anhydrase, and aquaporin 1, that may be targets for pharmacological up-regulation of cerebrospinal fluid formation. The search for potentially beneficial drugs useful to ameliorate Alzheimer's disease by facilitating cerebrospinal fluid production and turnover may be an important area for future research. However, the ultimate utility of such modulators in the management of Alzheimer's disease remains to be determined. Here, we hypothesize that caffeine, the most commonly used psychoactive drug in the world, may be an attractive therapeutic candidate for treatment of Alzheimer's disease since long-term caffeine consumption may augment cerebrospinal fluid production. Other potential mechanisms of cognitive protection by caffeine have been suggested by recent studies.


2021 ◽  
Vol 11 (2) ◽  
pp. 215
Author(s):  
Donovan A. McGrowder ◽  
Fabian Miller ◽  
Kurt Vaz ◽  
Chukwuemeka Nwokocha ◽  
Cameil Wilson-Clarke ◽  
...  

Alzheimer’s disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer’s disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer’s disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer’s disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer’s disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.


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.


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.


2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Sung-Soo Jang ◽  
Hee Jung Chung

Alzheimer’s disease (AD) is an irreversible brain disorder characterized by progressive cognitive decline and neurodegeneration of brain regions that are crucial for learning and memory. Although intracellular neurofibrillary tangles and extracellular senile plaques, composed of insoluble amyloid-β(Aβ) peptides, have been the hallmarks of postmortem AD brains, memory impairment in early AD correlates better with pathological accumulation of soluble Aβoligomers and persistent weakening of excitatory synaptic strength, which is demonstrated by inhibition of long-term potentiation, enhancement of long-term depression, and loss of synapses. However, current, approved interventions aiming to reduce Aβlevels have failed to retard disease progression; this has led to a pressing need to identify and target alternative pathogenic mechanisms of AD. Recently, it has been suggested that the disruption of Hebbian synaptic plasticity in AD is due to aberrant metaplasticity, which is a form of homeostatic plasticity that tunes the magnitude and direction of future synaptic plasticity based on previous neuronal or synaptic activity. This review examines emerging evidence for aberrant metaplasticity in AD. Putative mechanisms underlying aberrant metaplasticity in AD will also be discussed. We hope this review inspires future studies to test the extent to which these mechanisms contribute to the etiology of AD and offer therapeutic targets.


2008 ◽  
Vol 4 ◽  
pp. T145-T145
Author(s):  
John S.K. Kauwe ◽  
Carlos Cruchaga ◽  
Kevin Mayo ◽  
Chiara Fenoglio ◽  
Sarah Bertelsen ◽  
...  

2017 ◽  
Vol 58 (3) ◽  
pp. 821-828 ◽  
Author(s):  
Mikael Edsbagge ◽  
Ulf Andreasson ◽  
Khalid Ambarki ◽  
Carsten Wikkelsø ◽  
Anders Eklund ◽  
...  

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