scholarly journals Cell Type Specific Expression of Toll-Like Receptors in Human Brains and Implications in Alzheimer’s Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Henriette R. Frederiksen ◽  
Henriette Haukedal ◽  
Kristine Freude
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cellular Response ◽  
The Body ◽  
Cellular Damage ◽  
Whole Body ◽  
Toll Like Receptors ◽  
Cell Type ◽  
Cell Type Specific ◽  
The Brain

Toll-like receptors mediate important cellular immune responses upon activation via various pathogenic stimuli such as bacterial or viral components. The activation and subsequent secretion of cytokines and proinflammatory factors occurs in the whole body including the brain. The subsequent inflammatory response is crucial for the immune system to clear the pathogen(s) from the body via the innate and adaptive immune response. Within the brain, astrocytes, neurons, microglia, and oligodendrocytes all bear unique compositions of Toll-like receptors. Besides pathogens, cellular damage and abnormally folded protein aggregates, such as tau and Amyloid beta peptides, have been shown to activate Toll-like receptors in neurodegenerative diseases such as Alzheimer’s disease. This review provides an overview of the different cell type-specific Toll-like receptors of the human brain, their activation mode, and subsequent cellular response, as well as their activation in Alzheimer’s disease. Finally, we critically evaluate the therapeutic potential of targeting Toll-like receptors for treatment of Alzheimer’s disease as well as discussing the limitation of mouse models in understanding Toll-like receptor function in general and in Alzheimer’s disease.

scholarly journals Astrocytic Propagation of Tau in the Context of Alzheimer's Disease

2021 ◽  
Vol 15 ◽  
Author(s):  
Rebecca M. Fleeman ◽  
Elizabeth A. Proctor
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Significance ◽  
Glial Cells ◽  
Cell Type ◽  
Tau Pathology ◽  
Specific Effects ◽  
Signaling Mechanisms ◽  
Cell Type Specific ◽  
The Brain

More than 6 million Americans are currently living with Alzheimer's disease (AD), and the incidence is growing rapidly with our aging population. Numerous therapeutics have failed to make it to the clinic, potentially due to a focus on presumptive pathogenic proteins instead of cell-type-specific signaling mechanisms. The tau propagation hypothesis that inter-neuronal tau transfer drives AD pathology has recently garnered attention, as accumulation of pathological tau in the brain has high clinical significance in correlating with progression of cognitive AD symptoms. However, studies on tau pathology in AD are classically neuron-centric and have greatly overlooked cell-type specific effects of tau internalization, degradation, and propagation. While the contribution of microglia to tau processing and propagation is beginning to be recognized and understood, astrocytes, glial cells in the brain important for maintaining neuronal metabolic, synaptic, trophic, and immune function which can produce, internalize, degrade, and propagate tau are understudied in their ability to affect AD progression through tau pathology. Here, we showcase evidence for whether tau uptake by astrocytes may be beneficial or detrimental to neuronal health and how astrocytes and their immunometabolic functions may be key targets for future successful AD therapies.

scholarly journals Transferrin Biosynthesized in the Brain Is a Novel Biomarker for Alzheimer’s Disease

Metabolites ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 616
Author(s):  
Kyoka Hoshi ◽  
Hiromi Ito ◽  
Eriko Abe ◽  
Takashi J. Fuwa ◽  
Mayumi Kanno ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Hippocampal Neurons ◽  
Neurological Diseases ◽  
Ultra Performance Liquid Chromatography ◽  
Cell Type ◽  
Post Translational Modification ◽  
A Cell ◽  
Cell Type Specific ◽  
The Brain

Glycosylation is a cell type-specific post-translational modification that can be used for biomarker identification in various diseases. Aim of this study is to explore glycan-biomarkers on transferrin (Tf) for Alzheimer’s disease (AD) in cerebrospinal fluid (CSF). Glycan structures of CSF Tf were analyzed by ultra-performance liquid chromatography followed by mass spectrometry. We found that a unique mannosylated-glycan is carried by a Tf isoform in CSF (Man-Tf). The cerebral cortex contained Man-Tf as a major isofom, suggesting that CSF Man-Tf is, at least partly, derived from the cortex. Man-Tf levels were analyzed in CSF of patients with neurological diseases. Concentrations of Man-Tf were significantly increased in AD and mild cognitive impairment (MCI) comparing with other neurological diseases, and the levels correlated well with those of phosphorylated-tau (p-tau), a representative AD marker. Consistent with the observation, p-tau and Tf were co-expressed in hippocampal neurons of AD, leading to the notion that a combined p-tau and Man-Tf measure could be a biomarker for AD. Indeed, levels of p-tau x Man-Tf showed high diagnostic accuracy for MCI and AD; 84% sensitivities and 90% specificities for MCI and 94% sensitivities and 89% specificities for AD. Thus Man-Tf could be a new biomarker for AD.

Alzheimer’s disease and its related Dementia types: A review on their management via nanotechnology based therapeutic strategies

2021 ◽  
Vol 18 ◽  
Author(s):  
Panoraia I. Siafaka ◽  
Gökce Mutlu ◽  
Neslihan Üstündağ Okur
Keyword(s):  
Alzheimer’S Disease ◽  
Drug Delivery ◽  
Alzheimer's Disease ◽  
Vascular Dementia ◽  
Drug Delivery Systems ◽  
Delivery Systems ◽  
The Body ◽  
Daily Routine ◽  
Mixed Dementia ◽  
The Brain

Background: Dementia and its related types such as Alzheimer’s disease, vascular dementia and mixed dementia belong to brain associated diseases, resulting in long-term progressive memory loss. These diseases are so severe that can affect a person's daily routine. Up to date, treatment of de- mentias is still an unmet challenge due to their complex pathophysiology and unavailable efficient pharmacological approaches. The use of nanotechnology based pharmaceutical products could possibly improve the management of dementia given that nanocarriers could more efficiently deliver drugs to the brain. Objective: The objective of this study is to provide the current nanotechnology based drug delivery systems for the treatment of various dementia types. In addition, the current diagnosis biomarkers for the mentioned dementia types along with their available pharmacological treatment are being dis- cussed. Method: An extensive review of the current nanosystems such as brain drug delivery systems against Alzheimer’s disease, vascular dementia and mixed dementia was performed. Moreover, nan- otheranostics as possible imaging markers for such dementias were also reported. Results: The field of nanotechnology is quite advantageous for targeting dementia given that nanoscale drug delivery systems easily penetrate the blood brain barrier and circulate in the body for prolonged time. These nanoformulations consist of polymeric nanoparticles, solid lipid nanoparticles, nanostruc- tured lipid carriers, microemulsions, nanoemulsions, and liquid crystals. The delivery of the nan- otherapeutics can be achieved via various administration routes such as transdermal, injectable, oral, and more importantly, through the intranasal route. Nonetheless, the nanocarriers are mostly limited to Alzheimer’s disease targeting; thus, nanocarriers for other types of dementia should be developed. Conclusion: To conclude, understanding the mechanism of neurodegeneration and reviewing the cur- rent drug delivery systems for Alzheimer’s disease and other dementia types are significant for medical and pharmaceutical society to produce efficient therapeutic choices and novel strategies based on mul- tifunctional and biocompatible nanocarriers, which can deliver the drug sufficiently into the brain.

scholarly journals Cell Type-Specific Human APP Transgene Expression by Hippocampal Interneurons in the Tg2576 Mouse Model of Alzheimer’s Disease

2019 ◽  
Vol 13 ◽  
Author(s):  
Corinna Höfling ◽  
Emira Shehabi ◽  
Peer-Hendrik Kuhn ◽  
Stefan F. Lichtenthaler ◽  
Maike Hartlage-Rübsamen ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Model ◽  
Transgene Expression ◽  
Tg2576 Mouse ◽  
Cell Type ◽  
Model Of Alzheimer’S Disease ◽  
Cell Type Specific

scholarly journals Single-nucleus transcriptome analysis reveals dysregulation of angiogenic endothelial cells and neuroprotective glia in Alzheimer’s disease

2020 ◽  
Vol 117 (41) ◽  
pp. 25800-25809 ◽  
Author(s):  
Shun-Fat Lau ◽  
Han Cao ◽  
Amy K. Y. Fu ◽  
Nancy Y. Ip
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Endothelial Cells ◽  
Transcriptome Analysis ◽  
Cell Type ◽  
Angiogenic Growth Factors ◽  
Cellular Targets ◽  
Therapeutic Development ◽  
Single Nucleus ◽  
Cell Type Specific

Alzheimer’s disease (AD) is the most common form of dementia but has no effective treatment. A comprehensive investigation of cell type-specific responses and cellular heterogeneity in AD is required to provide precise molecular and cellular targets for therapeutic development. Accordingly, we perform single-nucleus transcriptome analysis of 169,496 nuclei from the prefrontal cortical samples of AD patients and normal control (NC) subjects. Differential analysis shows that the cell type-specific transcriptomic changes in AD are associated with the disruption of biological processes including angiogenesis, immune activation, synaptic signaling, and myelination. Subcluster analysis reveals that compared to NC brains, AD brains contain fewer neuroprotective astrocytes and oligodendrocytes. Importantly, our findings show that a subpopulation of angiogenic endothelial cells is induced in the brain in patients with AD. These angiogenic endothelial cells exhibit increased expression of angiogenic growth factors and their receptors (i.e.,EGFL7,FLT1, andVWF) and antigen-presentation machinery (i.e.,B2MandHLA-E). This suggests that these endothelial cells contribute to angiogenesis and immune response in AD pathogenesis. Thus, our comprehensive molecular profiling of brain samples from patients with AD reveals previously unknown molecular changes as well as cellular targets that potentially underlie the functional dysregulation of endothelial cells, astrocytes, and oligodendrocytes in AD, providing important insights for therapeutic development.

scholarly journals TRANSGENIC MOUSE MODELS OF ALZHEIMER’S DISEASE

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S835-S835
Author(s):  
Charnae A Henry-Smith ◽  
Xianlin Han
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Mouse Models ◽  
Myelin Sheath ◽  
Thinking Skills ◽  
Drug Dosage ◽  
Whole Body ◽  
To Receive ◽  
The Brain

Abstract Alzheimer’s disease is a progressive brain disease that slowly destroys memory and thinking skills. Alzheimer’s is characterized by an increase in Aβ plaques , and tau tangles. Neurons in the brain have axons covered in myelin sheath that connect microglia and astrocytes. The myelin sheath is composed of about 70% lipid composition; Sulfatide contributing to 30% overall. Sulfatide changes the morphology of primary microglia to their activated form. To study the role of microglia activation and sulfatide levels, three different mouse models were created: APP KI mice, CST Whole Body Ko mice, and cCST (conditional) KO. In order to create the genotype of the APP KI mice, a breeding mouse line was created. The APP KI gene had to be introduced in Plp1-Cre and cCST KO crossed mice to receive a working mouse model. During the duration of breeding for the APP KI mice, a preliminary experiment was performed on the CST KO mice. These mice were given the PLX3397 diet with the aim to remove the microglia and to see the effect of Aβ plaques. The PLX3397 will reduce the microglia targeting the CSF1R. After consuming the diet, the mice were harvested to collect tissues from the brain and spinal cord. Lipidomics and immunohistology were performed. In conclusion, we will continue the breeding of the CST flox/flox / Plp1-Cre / APP KI mice, and the drug dosage and treatment to be used in our APP KI mice will be based on preliminary data from our CST mice.

scholarly journals Proteinase-Activated Receptor-2 Exerts Protective and Pathogenic Cell Type-Specific Effects in Alzheimer’s Disease

2007 ◽  
Vol 179 (8) ◽  
pp. 5493-5503 ◽  
Author(s):  
Amir Afkhami-Goli ◽  
Farshid Noorbakhsh ◽  
Avril J. Keller ◽  
Nathalie Vergnolle ◽  
David Westaway ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cell Type ◽  
Specific Effects ◽  
Cell Type Specific

scholarly journals Influencia del estrés en la Enfermedad de Alzheimer. // Stress influence in Alzheimer’s disease

Ciencia Unemi ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 123
Author(s):  
Maria Alejandra Vallejo-Johnson ◽  
Patricia Marcial-Velastegui
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neuronal Damage ◽  
The Body ◽  
Daily Routine ◽  
Stressful Situation ◽  
The Individual ◽  
Stress Influences ◽  
The Brain

Existen diversos estudios que proponen las causas de la Enfermedad de Alzheimer (EA), las cuales pueden ser: biológicas, genéticas, cronológicas y ambientales, dentro de ésta última se encuentra el estrés como una influencia para el inicio de dicha patología. Según las distintas teorías del estrés, el sujeto, al encontrarse frente a una situación estresante, sufre diversos cambios en su cuerpo para sobrellevar dicho acontecimiento. El cerebro es el encargado de poner al cuerpo en alerta y en marcha para actuar frente a dicho cambio. El estrés prolongado conlleva a alteraciones en las vías cerebrales, específicamente un daño neuronal del hipocampo, el cual es el encargado de los recuerdos y memoria. Éste al verse afectado, repercute en la memoria del sujeto y por lo tanto empieza a fallar; el sujeto se ve en la incapacidad para recordar y realizar distintas actividades rutinarias. Mediante la investigación documental y encuestas a profesionales de la salud, se obtuvo información tanto del estrés como de la Enfermedad de Alzheimer para luego concluir en la influencia del mismo en el origen de la enfermedad. Se concluye que el estrés perenne repercute en la muerte de neuronas del hipocampo lo que conlleva a la EA. AbstractThere are different studies that propose that the causes of Alzheimer might be biological, genetic, chronological and environmental. Within the environmental aspects, the stress influences the beginning of this pathology. There are several studies that propose the causes of Alzheimer's disease (AD), which can be: biological, genetic, chronological and environmental, within the latter is the stress that influences the beginning of this pathology. According to different theories of stress, the individual, while facing a stressful situation, experiences many changes in the body in order to deal with this situation. The brain is in charge of alerting the body to protect itself against that change. The long-term stress alters the brain pathways, producing specifically a neuronal damage in the hippocampus that is responsible for memories and memory. This affects memory and therefore individual begins to fail, and then, the person cannot remember how to do the daily routine. Through bibliographical research and surveys applied to healthcare professionals, information was obtained on both stress and Alzheimer's disease to establish the influence of that condition on the disease. The study concludes that long-term stress affects the death of neurons in the hippocampus, which leads to AD.

scholarly journals How Your Blood Knows Your Brain Is Sick

2020 ◽  
Vol 8 ◽  
Author(s):  
Sabrina Loudjani ◽  
Sridar Narayanan ◽  
Arsalan S. Haqqani ◽  
AmanPreet Badhwar
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Complex Disease ◽  
The Body ◽  
The Brain

Alzheimer’s disease (AD) is a complex disease that attacks the brain that mostly affects people 65 years and older. AD affects more and more people each year. A major problem with AD is that it is diagnosed too late. A big goal is to find ways to help doctors identify the disease early, so they can better help AD patients. Biomarkers are something that can tell you if a part of the body is feeling healthy or is being attacked by a disease. This article will describe one exciting new category of biomarkers that carry information from the brain into the blood. These biomarkers can be used to see how healthy the brain is feeling or if it is getting hurt by a disease like AD.

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