Secretion of full-length Tau or Tau fragments in cell culture models. Propagation of Tau in vivo and in vitro

AbstractThe microtubule-associated protein Tau plays a crucial role in stabilizing neuronal microtubules. In Tauopathies, Tau loses its ability to bind microtubules, detach from them and forms intracellular aggregates. Increasing evidence in recent years supports the notion that Tau pathology spreading throughout the brain in AD and other Tauopathies is the consequence of the propagation of specific Tau species along neuroanatomically connected brain regions in a so-called “prion-like” manner. A number of steps are assumed to be involved in this process, including secretion, cellular uptake, transcellular transfer and/or seeding, although the precise mechanisms underlying propagation of Tau pathology are not fully understood yet. This review summarizes recent evidence on the nature of the specific Tau species that are propagated and the different mechanisms of Tau pathology spreading.

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In vitro models of the blood–brain barrier: An overview of commonly used brain endothelial cell culture models and guidelines for their use

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x16630991 ◽

2016 ◽

Vol 36 (5) ◽

pp. 862-890 ◽

Cited By ~ 269

Author(s):

Hans C Helms ◽

N Joan Abbott ◽

Malgorzata Burek ◽

Romeo Cecchelli ◽

Pierre-Olivier Couraud ◽

...

Keyword(s):

Cell Culture ◽

Endothelial Cell ◽

Blood Brain Barrier ◽

Brain Parenchyma ◽

Brain Barrier ◽

Blood Brain ◽

Culture Models ◽

Cell Culture Models ◽

The Brain

The endothelial cells lining the brain capillaries separate the blood from the brain parenchyma. The endothelial monolayer of the brain capillaries serves both as a crucial interface for exchange of nutrients, gases, and metabolites between blood and brain, and as a barrier for neurotoxic components of plasma and xenobiotics. This “blood-brain barrier” function is a major hindrance for drug uptake into the brain parenchyma. Cell culture models, based on either primary cells or immortalized brain endothelial cell lines, have been developed, in order to facilitate in vitro studies of drug transport to the brain and studies of endothelial cell biology and pathophysiology. In this review, we aim to give an overview of established in vitro blood–brain barrier models with a focus on their validation regarding a set of well-established blood–brain barrier characteristics. As an ideal cell culture model of the blood–brain barrier is yet to be developed, we also aim to give an overview of the advantages and drawbacks of the different models described.

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Optimizations of In Vitro Mucus and Cell Culture Models to Better Predict In Vivo Gene Transfer in Pathological Lung Respiratory Airways: Cystic Fibrosis as an Example

Pharmaceutics ◽

10.3390/pharmaceutics13010047 ◽

2020 ◽

Vol 13 (1) ◽

pp. 47

Author(s):

Rosy Ghanem ◽

Véronique Laurent ◽

Philippe Roquefort ◽

Tanguy Haute ◽

Sophie Ramel ◽

...

Keyword(s):

Cystic Fibrosis ◽

Gene Therapy ◽

Cell Culture ◽

Gene Transfer ◽

Gene Delivery ◽

Culture Models ◽

Transfer Strategies ◽

Cell Culture Models

The respiratory epithelium can be affected by many diseases that could be treated using aerosol gene therapy. Among these, cystic fibrosis (CF) is a lethal inherited disease characterized by airways complications, which determine the life expectancy and the effectiveness of aerosolized treatments. Beside evaluations performed under in vivo settings, cell culture models mimicking in vivo pathophysiological conditions can provide complementary insights into the potential of gene transfer strategies. Such models must consider multiple parameters, following the rationale that proper gene transfer evaluations depend on whether they are performed under experimental conditions close to pathophysiological settings. In addition, the mucus layer, which covers the epithelial cells, constitutes a physical barrier for gene delivery, especially in diseases such as CF. Artificial mucus models featuring physical and biological properties similar to CF mucus allow determining the ability of gene transfer systems to effectively reach the underlying epithelium. In this review, we describe mucus and cellular models relevant for CF aerosol gene therapy, with a particular emphasis on mucus rheology. We strongly believe that combining multiple pathophysiological features in single complex cell culture models could help bridge the gaps between in vitro and in vivo settings, as well as viral and non-viral gene delivery strategies.

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Turnover of the Active Fraction of IRS1 Involves Raptor-mTOR- and S6K1-Dependent Serine Phosphorylation in Cell Culture Models of Tuberous Sclerosis

Molecular and Cellular Biology ◽

10.1128/mcb.01254-05 ◽

2006 ◽

Vol 26 (17) ◽

pp. 6425-6434 ◽

Cited By ~ 119

Author(s):

O. Jameel Shah ◽

Tony Hunter

Keyword(s):

Cell Culture ◽

Tuberous Sclerosis ◽

High Speed ◽

Serine Phosphorylation ◽

Feedback Signal ◽

Insulin Receptor Substrates ◽

Igf I ◽

Culture Models ◽

Cell Culture Models

ABSTRACT The TSC1-TSC2/Rheb/Raptor-mTOR/S6K1 cell growth cassette has recently been shown to regulate cell autonomous insulin and insulin-like growth factor I (IGF-I) sensitivity by transducing a negative feedback signal that targets insulin receptor substrates 1 and 2 (IRS1 and -2). Using two cell culture models of the familial hamartoma syndrome, tuberous sclerosis, we show here that Raptor-mTOR and S6K1 are required for phosphorylation of IRS1 at a subset of serine residues frequently associated with insulin resistance, including S307, S312, S527, S616, and S636 (of human IRS1). Using loss- and gain-of-function S6K1 constructs, we demonstrate a requirement for the catalytic activity of S6K1 in both direct and indirect regulation of IRS1 serine phosphorylation. S6K1 phosphorylates IRS1 in vitro on multiple residues showing strong preference for RXRXXS/T over S/T,P sites. IRS1 is preferentially depleted from the high-speed pellet fraction in TSC1/2-deficient mouse embryo fibroblasts or in HEK293/293T cells overexpressing Rheb. These studies suggest that, through serine phosphorylation, Raptor-mTOR and S6K1 cell autonomously promote the depletion of IRS1 from specific intracellular pools in pathological states of insulin and IGF-I resistance and thus potentially in lesions associated with tuberous sclerosis.

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Conjunctival melanoma and electrochemotherapy: preliminary results using 2D and 3D cell culture models in vitro

Acta Ophthalmologica ◽

10.1111/aos.13993 ◽

2018 ◽

Vol 97 (4) ◽

pp. e632-e640 ◽

Cited By ~ 4

Author(s):

Miltiadis Fiorentzis ◽

Periklis Katopodis ◽

Helen Kalirai ◽

Berthold Seitz ◽

Arne Viestenz ◽

...

Keyword(s):

Cell Culture ◽

3D Cell Culture ◽

Conjunctival Melanoma ◽

Preliminary Results ◽

Culture Models ◽

2D And 3D ◽

Cell Culture Models

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Applying phasor approach analysis of multiphoton FLIM measurements to probe the metabolic activity of three-dimensional in vitro cell culture models

Scientific Reports ◽

10.1038/srep42730 ◽

2017 ◽

Vol 7 (1) ◽

Cited By ~ 25

Author(s):

Pirmin H. Lakner ◽

Michael G. Monaghan ◽

Yvonne Möller ◽

Monilola A. Olayioye ◽

Katja Schenke-Layland

Keyword(s):

Cell Culture ◽

Metabolic Activity ◽

Three Dimensional ◽

In Vitro Cell Culture ◽

Culture Models ◽

Cell Culture Models

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Neurotoxic astrocytic glypican-4 drives APOE4-dependent tau pathology

10.1101/2021.07.07.451493 ◽

2021 ◽

Author(s):

Sivaprakasam Ramamoorthy ◽

Kirill Gorbachev ◽

Ana Pereira

Keyword(s):

Late Onset ◽

Low Density Lipoprotein ◽

Density Lipoprotein ◽

Brain Regions ◽

Tau Proteins ◽

Tau Pathology ◽

Density Lipoprotein Receptor ◽

Apoe Receptor ◽

The Brain

Apolipoprotein E4 (APOE4) is the crucial genetic risk factor of late-onset Alzheimer disease (AD). Aggregation of tau proteins into insoluble filaments and their spreading across the brain regions are major drivers of neurodegeneration in tauopathies, including in AD. However, the exact mechanisms through which APOE4 induces tau pathology remains unknown. Here, we report that the astrocyte-secreted protein glypican-4 (GPC-4), a novel binding partner of APOE4, drives tau pathology. GPC-4 preferentially interacts with APOE4 in comparison to other APOE isoforms and post-mortem APOE4-carrying AD brains highly express GPC-4 in neurotoxic astrocytes. The astrocyte-secreted GPC-4 induced both tau accumulation and propagation in vitro. CRISPR/dCas9 mediated activation of GPC-4 in a tauopathy animal model robustly induced tau pathology. Further, APOE4-induced tau pathology was greatly diminished in the absence of GPC-4. We found that GPC-4 promoted the stabilization of the APOE receptor low-density lipoprotein receptor-related protein 1 (LRP1) on the cellular surface, which effectively facilitates endocytosis of tau protein. Together, our data comprehensively demonstrate that one of the key APOE4-induced tau pathologies is directly mediated by GPC-4.

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