The role of Glial Cells in Alzheimer’s disease part1(Neuroscience)
- Glial Cells — The Key Elements of Alzheimer´s Disease(PubMed)
Author : David Dzamba, Lenka Harantova, Olena Butenko, Miroslava Anderova
Abstract : Alzheimer’s disease (AD) is a complex neurodegenerative disorder with major clinical hallmarks of memory loss, dementia, and cognitive impairment. Besides the extensive neuron-oriented research, an increasing body of evidence suggests that glial cells, namely astrocytes, microglia, NG2 glia and oligodendrocytes, may play an important role in the pathogenesis of this disease. In the first part of this review, AD pathophysiology in humans is briefly described and compared with disease progression in routinely used animal models. The relevance of findings obtained in animal models of AD is also discussed with respect to AD pathology in humans. Further, this review summarizes recent findings regarding the role/participation of glial cells in pathogenesis of AD, focusing on changes in their morphology, functions, proteins and gene expression profiles. As for astrocytes and microglia, they are fundamental for the progression and outcome of AD either because they function as effector cells releasing cytokines that play a role in neuroprotection, or because they fail to fulfill their homeostatic functions, ultimately leaving neurons to face excitotoxicity and oxidative stress. Next, we turn our attention towards NG2 glia, a novel and distinct class of glial cells in the central nervous system (CNS), whose role in a variety of human CNS diseases has begun to emerge, and we also consider the participation of oligodendrocytes in the pathogenesis and progression of AD. Since AD is currently an incurable disease, in the last part of our review we hypothesize about possible glia-oriented treatments and provide a perspective of possible future advancements in this field.
2. Critical Involvement of Glial Cells in Manganese Neurotoxicity(PubMed)
Author : Jazmín Soto-Verdugo , Arturo Ortega
Abstract : Over the years, most of the research concerning manganese exposure was restricted to the toxicity of neuronal cells. Manganese is an essential trace element that in high doses exerts neurotoxic effects. However, in the last two decades, efforts have shifted toward a more comprehensive approach that takes into account the involvement of glial cells in the development of neurotoxicity as a brain insult. Glial cells provide structural, trophic, and metabolic support to neurons. Nevertheless, these cells play an active role in adult neurogenesis, regulation of synaptogenesis, and synaptic plasticity. Disturbances in glial cell function can lead to neurological disorders, including neurodegenerative diseases. This review highlights the pivotal role that glial cells have in manganese-induced neurotoxicity as well as the most sounding mechanisms involved in the development of this phenomenon
3.Glial cells of the human fovea (PubMed)
Author : Kimberley Delaunay , Lilly Khamsy , Laura Kowalczuk , Alexandre Moulin , Michaël Nicolas , Leonidas Zografos , Patricia Lassiaz , Francine Behar-Cohen
Abstract : Purpose: The exact cellular types that form the human fovea remain a subject of debate, and few studies have been conducted on human macula to solve this question. The purpose of this study was to perform immunohistochemistry on fresh human samples to characterize the glial cells that form the human fovea.
Methods: Immunohistochemistry was performed using antibodies against proteins expressed in astrocytes or in retinal Müller glial cells or both types of cells on six human macula obtained from eyes enucleated for peripheral intraocular tumors and on two postmortem eyes from healthy donors. The posterior poles of the enucleated eyes were cryosectioned and stained with antibodies against the glial proteins GFAP, vimentin, CRALBP, glutamine synthetase, and connexin 43.
Results: A population of cells positive for GFAP and negative for glutamine synthetase and CRALBP that express connexin 43 were identified at the roof of the foveal pit. These cells are distinct from the Müller cone cells described by Yamada and Gass, suggesting that another type of foveal glial cells, most likely astrocytes, are present in the human fovea.
Conclusions: This study showed that in humans, astrocytic glial cells cover the foveal pit. Their roles in macula homeostasis and mechanisms of macular diseases disease remain to be determined.
