scholarly journals The Role of Lipid Environment in Ganglioside GM1-Induced Amyloid β Aggregation

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 226
Author(s):  
Vladimir Rudajev ◽  
Jiri Novotny
Keyword(s):  
Spatial Organization ◽  
Amyloid Β ◽  
Conformational Flexibility ◽  
Membrane Microdomains ◽  
Ganglioside Gm1 ◽  
Neuronal Tissue ◽  
Neuronal Membranes ◽  
Negative Role ◽  
Lipid Environment

Ganglioside GM1 is the most common brain ganglioside enriched in plasma membrane regions known as lipid rafts or membrane microdomains. GM1 participates in many modulatory and communication functions associated with the development, differentiation, and protection of neuronal tissue. It has, however, been demonstrated that GM1 plays a negative role in the pathophysiology of Alzheimer’s disease (AD). The two features of AD are the formation of intracellular neurofibrillary bodies and the accumulation of extracellular amyloid β (Aβ). Aβ is a peptide characterized by intrinsic conformational flexibility. Depending on its partners, Aβ can adopt different spatial arrangements. GM1 has been shown to induce specific changes in the spatial organization of Aβ, which lead to enhanced peptide accumulation and deleterious effect especially on neuronal membranes containing clusters of this ganglioside. Changes in GM1 levels and distribution during the development of AD may contribute to the aggravation of the disease.

Role for lipid rafts in regulating interleukin-2 receptor signaling

Blood ◽  
2001 ◽  
Vol 98 (5) ◽  
pp. 1489-1497 ◽  
Author(s):  
Mina D. Marmor ◽  
Michael Julius
Keyword(s):  
Lipid Rafts ◽  
Interleukin 2 ◽  
Phosphatidyl Inositol ◽  
Membrane Microdomains ◽  
Lipid Microdomains ◽  
Interleukin 2 Receptor ◽  
Lipid Environment ◽  
Plasma Membrane Microdomains ◽  
Nonionic Detergents

Lipid rafts are plasma membrane microdomains characterized by a unique lipid environment enriched in gangliosides and cholesterol, leading to their insolubility in nonionic detergents. Many receptors are constitutively or inducibly localized in lipid rafts, which have been shown to function as platforms coordinating the induction of signaling pathways. In this report, the first evidence is provided for a role of these lipid microdomains in regulating interleukin-2 receptor (IL-2R) signaling. It is demonstrated that antibody- or ligand-mediated immobilization of components of lipid rafts, glycosyl-phosphatidyl-inositol–anchored proteins, and the GM1 ganglioside, respectively, inhibit IL-2–induced proliferation in T cells. IL-2Rα is shown to be constitutively enriched in rafts and further enriched in the presence of immobilized anti–Thy-1. In contrast, IL-2Rβ and IL-2Rγ, as well as JAK1 and JAK3, are found in soluble membrane fractions, and their localization is not altered by anti–Thy-1. IL-2–mediated heterotrimerization of IL-2R chains is shown to occur within soluble membrane fractions, exclusively, as is the activation of JAK1 and JAK3. As predicted by these results, the disruption of lipid raft integrity did not impair IL-2–induced signaling. Thus, the sequestration of IL-2Rα within lipid microdomains restricts its intermolecular interactions and regulates IL-2R signaling through impeding its association with IL-2Rβ and IL-2Rγ.

scholarly journals The glycolipid GM1 reshapes asymmetric biomembranes and giant vesicles by curvature generation

2018 ◽  
Vol 115 (22) ◽  
pp. 5756-5761 ◽  
Author(s):  
Raktim Dasgupta ◽  
Markus S. Miettinen ◽  
Nico Fricke ◽  
Reinhard Lipowsky ◽  
Rumiana Dimova
Keyword(s):  
Spontaneous Curvature ◽  
Intensity Analysis ◽  
Ganglioside Gm1 ◽  
Local Curvature ◽  
Giant Vesicles ◽  
Neuron Morphology ◽  
Receptor Proteins ◽  
Neuronal Membranes ◽  
Dynamics Simulations

The ganglioside GM1 is present in neuronal membranes at elevated concentrations with an asymmetric spatial distribution. It is known to generate curvature and can be expected to strongly influence the neuron morphology. To elucidate these effects, we prepared giant vesicles with GM1 predominantly present in one leaflet of the membrane, mimicking the asymmetric GM1 distribution in neuronal membranes. Based on pulling inward and outward tubes, we developed a technique that allowed the direct measurement of the membrane spontaneous curvature. Using vesicle electroporation and fluorescence intensity analysis, we were able to quantify the GM1 asymmetry across the membrane and to subsequently estimate the local curvature generated by the molecule in the bilayer. Molecular-dynamics simulations confirm the experimentally determined dependence of the membrane spontaneous curvature as a function of GM1 asymmetry. GM1 plays a crucial role in connection with receptor proteins. Our results on curvature generation of GM1 point to an additional important role of this ganglioside, namely in shaping neuronal membranes.

scholarly journals Mouse TRPA1 function and membrane localization are modulated by direct interactions with cholesterol

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Justyna B Startek ◽  
Brett Boonen ◽  
Alejandro López-Requena ◽  
Ariel Talavera ◽  
Yeranddy A Alpizar ◽  
...  
Keyword(s):  
Gradient Centrifugation ◽  
Membrane Microdomains ◽  
Membrane Localization ◽  
Cholesterol Depletion ◽  
Transmembrane Segments ◽  
Neuropeptide Release ◽  
Chemical Stimuli ◽  
Lipid Environment ◽  
The Impact

The cation channel TRPA1 transduces a myriad of noxious chemical stimuli into nociceptor electrical excitation and neuropeptide release, leading to pain and neurogenic inflammation. Despite emergent evidence that TRPA1 is regulated by the membrane environment, it remains unknown whether this channel localizes in membrane microdomains or whether it interacts with cholesterol. Using total internal reflection fluorescence microscopy and density gradient centrifugation we found that mouse TRPA1 localizes preferably into cholesterol-rich domains and functional experiments revealed that cholesterol depletion decreases channel sensitivity to chemical agonists. Moreover, we identified two structural motifs in transmembrane segments 2 and 4 involved in mTRPA1-cholesterol interactions that are necessary for normal agonist sensitivity and plasma membrane localization. We discuss the impact of such interactions on TRPA1 gating mechanisms, regulation by the lipid environment, and role of this channel in sensory membrane microdomains, all of which helps to understand the puzzling pharmacology and pathophysiology of this channel.

A Geographical Study on Positive And Negative Role of Private Housing Cooperative Societies in Mysore City

2012 ◽  
Vol 3 (8) ◽  
pp. 55-58
Author(s):  
K.K. Somashekara K.K. Somashekara ◽  
◽  
B.N. Shivalingappa B.N. Shivalingappa
Keyword(s):  
Geographical Study ◽  
Housing Cooperative ◽  
Negative Role ◽  
Private Housing

Microglia in Alzheimer’s Disease

2020 ◽  
Vol 17 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Patrick Süß ◽  
Johannes C.M. Schlachetzki
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Disorder ◽  
Current Knowledge ◽  
Imaging Techniques ◽  
Amyloid Β ◽  
Disease Stage ◽  
Disease Modifying Therapy ◽  
Transcriptomic Signature

: Alzheimer’s Disease (AD) is the most frequent neurodegenerative disorder. Although proteinaceous aggregates of extracellular Amyloid-β (Aβ) and intracellular hyperphosphorylated microtubule- associated tau have long been identified as characteristic neuropathological hallmarks of AD, a disease- modifying therapy against these targets has not been successful. An emerging concept is that microglia, the innate immune cells of the brain, are major players in AD pathogenesis. Microglia are longlived tissue-resident professional phagocytes that survey and rapidly respond to changes in their microenvironment. Subpopulations of microglia cluster around Aβ plaques and adopt a transcriptomic signature specifically linked to neurodegeneration. A plethora of molecules and pathways associated with microglia function and dysfunction has been identified as important players in mediating neurodegeneration. However, whether microglia exert either beneficial or detrimental effects in AD pathology may depend on the disease stage. : In this review, we summarize the current knowledge about the stage-dependent role of microglia in AD, including recent insights from genetic and gene expression profiling studies as well as novel imaging techniques focusing on microglia in human AD pathology and AD mouse models.

scholarly journals Neuronutraceuticals Modulate Lipopolysaccharide- or Amyloid-β 1-42 Peptide-Induced Transglutaminase 2 Overexpression as a Marker of Neuroinflammation in Mouse Microglial Cells

2021 ◽  
Vol 11 (12) ◽  
pp. 5718
Author(s):  
Nicola Gaetano Gatta ◽  
Andrea Parente ◽  
Francesca Guida ◽  
Sabatino Maione ◽  
Vittorio Gentile
Keyword(s):  
Microglial Cell ◽  
Amyloid Β ◽  
Transglutaminase 2 ◽  
Microglial Cells ◽  
Tissue Type ◽  
Microglial Cell Line ◽  
Bv2 Cells ◽  
Important Marker

Background: Tissue type 2 transglutaminase (TG2, E.C. 2.3.2,13) is reported to be involved in the phagocytosis of apoptotic cells in mouse microglial BV2 cells and peripheral macrophages. In this study, by using lipopolysaccharide (LPS)- or amyloid-β 1-42 (Aβ 1-42) peptide-stimulated microglial cell line BV2 and mouse primary microglial cells, we examined the effects of different neuronutraceutical compounds, such as curcumin (Cu) and N-Palmitoylethanolamine (PEA), known for their anti-inflammatory activity, on TG2 and several inflammatory or neuroprotective biomarker expressions. Methods: Mouse BV2 cells were treated with LPS or Aβ1-42 in the presence of curcumin or PEA, in order to evaluate the expression of TG2 and other inflammatory or neuroprotective markers using Real Time-PCR and Western blot analyses. Results: Curcumin and PEA were capable of reducing TG2 expression in mouse microglial cells during co-treatment with LPS or Aβ 1-42. Conclusions: The results show the role of TG2 as an important marker of neuroinflammation and suggest a possible use of curcumin and PEA in order to reduce LPS- or Aβ1-42-induced TG2 overexpression in mouse microglial cells.

scholarly journals Astrocytes and neuroinflammation in Alzheimer's disease

2014 ◽  
Vol 42 (5) ◽  
pp. 1321-1325 ◽  
Author(s):  
Emma C. Phillips ◽  
Cara L. Croft ◽  
Ksenia Kurbatskaya ◽  
Michael J. O’Neill ◽  
Michael L. Hutton ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Inflammatory Responses ◽  
Amyloid Β ◽  
Synaptic Dysfunction ◽  
Amyloid Β Peptide ◽  
Substantial Evidence ◽  
Models Of Disease ◽  
Opposing Effects

Increased production of amyloid β-peptide (Aβ) and altered processing of tau in Alzheimer's disease (AD) are associated with synaptic dysfunction, neuronal death and cognitive and behavioural deficits. Neuroinflammation is also a prominent feature of AD brain and considerable evidence indicates that inflammatory events play a significant role in modulating the progression of AD. The role of microglia in AD inflammation has long been acknowledged. Substantial evidence now demonstrates that astrocyte-mediated inflammatory responses also influence pathology development, synapse health and neurodegeneration in AD. Several anti-inflammatory therapies targeting astrocytes show significant benefit in models of disease, particularly with respect to tau-associated neurodegeneration. However, the effectiveness of these approaches is complex, since modulating inflammatory pathways often has opposing effects on the development of tau and amyloid pathology, and is dependent on the precise phenotype and activities of astrocytes in different cellular environments. An increased understanding of interactions between astrocytes and neurons under different conditions is required for the development of safe and effective astrocyte-based therapies for AD and related neurodegenerative diseases.

scholarly journals Role of Membrane Microdomains in Compartmentation of cAMP Signaling

PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e95835 ◽  
Author(s):  
Shailesh R. Agarwal ◽  
Pei-Chi Yang ◽  
Monica Rice ◽  
Cherie A. Singer ◽  
Viacheslav O. Nikolaev ◽  
...  
Keyword(s):  
Camp Signaling ◽  
Membrane Microdomains

scholarly journals Ganglioside incorporation and release by the isolated perfused rat liver

1991 ◽  
Vol 274 (2) ◽  
pp. 581-585 ◽  
Author(s):  
S C Kivatinitz ◽  
A Miglio ◽  
R Ghidoni
Keyword(s):  
Rat Liver ◽  
The Other ◽  
Regulatory Role ◽  
Isolated Perfused Rat Liver ◽  
Order Kinetic ◽  
Perfused Rat Liver ◽  
Ganglioside Gm1 ◽  
First Order ◽  
Pseudo First Order

The fate of exogenous ganglioside GM1 labelled in the sphingosine moiety, [Sph-3H]GM1, administered as a pulse, in the isolated perfused rat liver was investigated. When a non-recirculating protocol was employed, the amount of radioactivity in the liver and perfusates was found to be dependent on the presence of BSA in the perfusion liquid and on the time elapsed after the administration of the ganglioside. When BSA was added to the perfusion liquid, less radioactivity was found in the liver and more in the perfusate at each time tested, for up to 1 h. The recovery of radioactivity in the perfusates followed a complex course which can be described by three pseudo-first-order kinetic constants. The constants, in order of decreasing velocity, are interpreted as: (a) the dilution of the labelled GM1 by the constant influx of perfusion liquid; (b) the washing off of GM1 loosely bound to the surface of liver cells; (c) the release of gangliosides from the liver. Process (b) was found to be faster in the presence of BSA, probably owing to the ability of BSA to bind gangliosides. The [Sph-3H]GM1 in the liver underwent metabolism, leading to the appearance of products of anabolic (GD1a, GD1b) and catabolic (GM2, GM3) origin; GD1a appeared before GM2 and GM3 but, at times longer than 10 min, GM2 and GM3 showed more radioactivity than GD1a. At a given time the distribution of the radioactivity in the perfusates was quite different from that of the liver. In fact, after 60 min GD1a was the only metabolite present in any amount, the other being GM3, the quantity of which was small. This indicates that the liver is able to release newly synthesized gangliosides quite specifically. When a recirculating protocol was used, there were more catabolites and less GD1a than with the non-recirculating protocol. A possible regulatory role of ganglioside re-internalization on their own metabolism in the liver is postulated.

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