scholarly journals TREM2 interacts with TDP-43 and mediates microglial neuroprotection against TDP-43-related neurodegeneration

Author(s):  
Manling Xie ◽  
Yong Liu ◽  
Shuyi Zhao ◽  
Lingxin Zhang ◽  
Dale Bosco ◽  
...  

Abstract Triggering receptor expressed on myeloid cell 2 (TREM2) is a surface receptor that, in the central nervous system, is exclusively expressed on microglia. TREM2 variants have been linked to increased risk for neurodegenerative diseases, but the functional effects of microglial TREM2 remain largely unknown. To this end, we investigated TAR-DNA binding protein 43 kDa (TDP-43)-related neurodegenerative disease via viral-mediated expression of human TDP-43 protein (hTDP-43) in mice or inducible expression of hTDP43 with defective nuclear localization signals in transgenic mice. We found that TREM2 deficiency impaired microglia phagocytic clearance of pathological TDP-43, and enhanced neuronal damage and motor function impairments. Mass cytometry analysis revealed that hTDP-43 induced a TREM2-dependent subpopulation of microglia with high CD11c expression and higher phagocytic ability. Using mass spectrometry, we further demonstrated an interaction between TDP-43 and TREM2, in vitro and in vivo, in hTDP-43-expressing transgenic mouse brains. We computationally identified the region within hTDP-43 that interacts with TREM2 and observed the potential interaction in ALS patient tissues. Our data reveal the novel interaction between TREM2 and TDP-43, highlighting that TDP-43 is a potential ligand for microglial TREM2 and the interaction mediates neuroprotection of microglial TREM2 in TDP-43-related neurodegeneration.

2021 ◽  
Author(s):  
Manling Xie ◽  
Yong U Liu ◽  
Shunyi Zhao ◽  
Lingxin Zhang ◽  
Dale B Bosco ◽  
...  

Triggering receptor expressed on myeloid cell 2 (TREM2) is a surface receptor that, in the central nervous system, is exclusively expressed on microglia. TREM2 variants have been linked to increased risk for neurodegenerative diseases, but the functional effects of microglial TREM2 remain largely unknown. To this end, we investigated TAR-DNA binding protein 43 kDa (TDP-43)-related neurodegenerative disease via viral-mediated expression of human TDP-43 protein (hTDP-43) in neonatal and adult mice or inducible expression of hTDP43 with defective nuclear localization signals in transgenic mice. We found that TREM2 deficiency impaired microglia phagocytic clearance of pathological TDP-43, and enhanced neuronal damage and motor function impairments. Mass cytometry analysis revealed that hTDP-43 induced a TREM2-dependent subpopulation of microglia with high CD11c expression and higher phagocytic ability. Using mass spectrometry and surface plasmon resonance analysis, we further demonstrated an interaction between TDP-43 and TREM2, in vitro and in vivo, in hTDP-43-expressing transgenic mouse brains. We computationally identified the region within hTDP-43 that interacts with TREM2 and observed the potential interaction in ALS patient tissues. Our data reveal the novel interaction between TREM2 and TDP-43, highlighting that TDP-43 is a possible ligand for microglial TREM2 and the interaction mediates neuroprotection of microglial TREM2 in TDP-43-related neurodegeneration.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 215 ◽  
Author(s):  
Peng ◽  
Wang

West Nile virus (WNV), a mosquito-borne, single-stranded flavivirus, has caused annual outbreaks of viral encephalitis in the United States since 1999. The virus induces acute infection with a clinical spectrum ranging from a mild flu-like febrile symptom to more severe neuroinvasive conditions, including meningitis, encephalitis, acute flaccid paralysis, and death. Some WNV convalescent patients also developed long-term neurological sequelae. Neither the treatment of WNV infection nor an approved vaccine is currently available for humans. Neuronal death in the central nervous system (CNS) is a hallmark of WNV-induced meningitis and encephalitis. However, the underlying mechanisms of WNV-induced neuronal damage are not well understood. In this review, we discuss current findings from studies of WNV infection in vitro in the CNS resident cells and the in vivo animal models, and provide insights into WNV-induced neuropathogenesis.


2021 ◽  
Vol 22 (12) ◽  
pp. 6196
Author(s):  
Anna Pieniazek ◽  
Joanna Bernasinska-Slomczewska ◽  
Lukasz Gwozdzinski

The presence of toxins is believed to be a major factor in the development of uremia in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Uremic toxins have been divided into 3 groups: small substances dissolved in water, medium molecules: peptides and low molecular weight proteins, and protein-bound toxins. One of the earliest known toxins is urea, the concentration of which was considered negligible in CKD patients. However, subsequent studies have shown that it can lead to increased production of reactive oxygen species (ROS), and induce insulin resistance in vitro and in vivo, as well as cause carbamylation of proteins, peptides, and amino acids. Other uremic toxins and their participation in the damage caused by oxidative stress to biological material are also presented. Macromolecules and molecules modified as a result of carbamylation, oxidative stress, and their adducts with uremic toxins, may lead to cardiovascular diseases, and increased risk of mortality in patients with CKD.


1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.


2021 ◽  
Vol 22 (9) ◽  
pp. 4670
Author(s):  
Cinzia Buccoliero ◽  
Manuela Dicarlo ◽  
Patrizia Pignataro ◽  
Francesco Gaccione ◽  
Silvia Colucci ◽  
...  

Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) is a protein that promotes transcription of numerous genes, particularly those responsible for the regulation of mitochondrial biogenesis. Evidence for a key role of PGC1α in bone metabolism is very recent. In vivo studies showed that PGC1α deletion negatively affects cortical thickness, trabecular organization and resistance to flexion, resulting in increased risk of fracture. Furthermore, in a mouse model of bone disease, PGC1α activation stimulates osteoblastic gene expression and inhibits atrogene transcription. PGC1α overexpression positively affects the activity of Sirtuin 3, a mitochondrial nicotinammide adenina dinucleotide (NAD)-dependent deacetylase, on osteoblastic differentiation. In vitro, PGC1α overexpression prevents the reduction of mitochondrial density, membrane potential and alkaline phosphatase activity caused by Sirtuin 3 knockdown in osteoblasts. Moreover, PGC1α influences the commitment of skeletal stem cells towards an osteogenic lineage, while negatively affects marrow adipose tissue accumulation. In this review, we will focus on recent findings about PGC1α action on bone metabolism, in vivo and in vitro, and in pathologies that cause bone loss, such as osteoporosis and type 2 diabetes.


2021 ◽  
Vol 12 (38) ◽  
pp. 12719-12725
Author(s):  
Maria Varghese ◽  
Rae S. Rokosh ◽  
Carolyn A. Haller ◽  
Stacy L. Chin ◽  
Jiaxuan Chen ◽  
...  

Heparin mimicking sulfated poly-amido-saccharides (sulPASs) are anticoagulants resistant to heparanases and reversed by protamine sulfate. In an in vivo murine model, sulPASs extend clotting time without the increased risk of bleeding.


1999 ◽  
Vol 43 (5) ◽  
pp. 1091-1097 ◽  
Author(s):  
Hideki Kita ◽  
Hirotami Matsuo ◽  
Hitomi Takanaga ◽  
Junichi Kawakami ◽  
Koujirou Yamamoto ◽  
...  

ABSTRACT We investigated the correlation between an in vivo isobologram based on the concentrations of new quinolones (NQs) in brain tissue and the administration of nonsteroidal anti-inflammatory drugs (NSAIDs) for the occurrence of convulsions in mice and an in vitro isobologram based on the concentrations of both drugs for changes in the γ-aminobutyric acid (GABA)-induced current response in Xenopus oocytes injected with mRNA from mouse brains in the presence of NQs and/or NSAIDs. After the administration of enoxacin (ENX) in the presence or absence of felbinac (FLB), ketoprofen (KTP), or flurbiprofen (FRP), a synergistic effect was observed in the isobologram based on the threshold concentration in brain tissue between mice with convulsions and those without convulsions. The three NSAIDs did not affect the pharmacokinetic behavior of ENX in the brain. However, the ENX-induced inhibition of the GABA response in the GABAA receptor expressed in Xenopus oocytes was enhanced in the presence of the three NSAIDs. The inhibition ratio profiles of the GABA responses for both drugs were analyzed with a newly developed toxicodynamic model. The inhibitory profiles for ENX in the presence of NSAIDs followed the order KTP (1.2 μM) > FRP (0.3 μM) > FLB (0.2 μM). These were 50- to 280-fold smaller than those observed in the absence of NSAIDs. The inhibition ratio (0.01 to 0.02) of the GABAA receptor in the presence of both drugs was well-fitted to the isobologram based on threshold concentrations of both drugs in brain tissue between mice with convulsions and those without convulsions, despite the presence of NSAIDs. In mice with convulsions, the inhibitory profiles of the threshold concentrations of both drugs in brain tissue of mice with convulsions and those without convulsions can be predicted quantitatively by using in vitro GABA response data and toxicodynamic model.


2005 ◽  
Vol 19 (7) ◽  
pp. 1884-1892 ◽  
Author(s):  
Helena Sim ◽  
Kieran Rimmer ◽  
Sabine Kelly ◽  
Louisa M. Ludbrook ◽  
Andrew H. A. Clayton ◽  
...  

Abstract The sex-determining region of the Y chromosome (SRY) plays a key role in human sex determination, as mutations in SRY can cause XY sex reversal. Although some SRY missense mutations affect DNA binding and bending activities, it is unclear how others contribute to disease. The high mobility group domain of SRY has two nuclear localization signals (NLS). Sex-reversing mutations in the NLSs affect nuclear import in some patients, associated with defective importin-β binding to the C-terminal NLS (c-NLS), whereas in others, importin-β recognition is normal, suggesting the existence of an importin-β-independent nuclear import pathway. The SRY N-terminal NLS (n-NLS) binds calmodulin (CaM) in vitro, and here we show that this protein interaction is reduced in vivo by calmidazolium, a CaM antagonist. In calmidazolium-treated cells, the dramatic reduction in nuclear entry of SRY and an SRY-c-NLS mutant was not observed for two SRY-n-NLS mutants. Fluorescence spectroscopy studies reveal an unusual conformation of SRY.CaM complexes formed by the two n-NLS mutants. Thus, CaM may be involved directly in SRY nuclear import during gonadal development, and disruption of SRY.CaM recognition could underlie XY sex reversal. Given that the CaM-binding region of SRY is well-conserved among high mobility group box proteins, CaM-dependent nuclear import may underlie additional disease states.


2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi213-vi213
Author(s):  
Nadim Tawil ◽  
Rayhaan Bassawon ◽  
Brian Meehan ◽  
Laura Montermini ◽  
Ali Nehme ◽  
...  

Abstract BACKGROUND Vascular anomalies, including thrombosis, are a hallmark of glioblastoma (GBM) and an aftermath of dysregulated cancer cell genome and epigenome. Up-regulation of podoplanin (PDPN) by cancer cells has recently been linked to an increased risk of venous thromboembolism in glioblastoma patients. Thus, regulation of this platelet activating protein by transforming events and release from cancer cells is of considerable interest. AIMS I. Investigate the pattern of PDPN expression and characterize PDPN-expressing cellular populations in GBM. II. Evaluate the contribution of oncogenic drivers to PDPN expression in GBM models. III. Investigate the potential involvement of extracellular vesicles (EVs) as a mechanism for systemic dissemination of PDPN and tissue factor (TF). IV. Examine the role of PDPN in intratumoral and systemic thrombosis. METHODS Bioinformatics (single-cell and bulk transcriptome data mining), GBM cell lines and stem cell lines, xenograft models in mice, ELISA assays for PDPN and TF, platelet (PF4) and clotting activation markers (D-dimer), EV electron microscopy, density gradient fractionation, and nano-flow cytometry. RESULTS PDPN is expressed by distinct glioblastoma cell subpopulations (mesenchymal) and downregulated by oncogenic mutations of EGFR and IDH1 genes, via changes in chromatin modifications (EZH2) and DNA methylation, respectively. GBM cells exteriorize PDPN and/or TF as cargo of exosome-like EVs shed both in vitro and in vivo. Injection of glioma PDPN-EVs activates platelets. Increase of platelet activation (PF4) or coagulation markers (D-dimer) occurs in mice harboring the corresponding glioma xenografts expressing PDPN or TF, respectively. Co-expression of PDPN and TF by GBM cells cooperatively increases tumor microthrombosis. CONCLUSION Distinct cellular subsets drive multiple facets of GBM-associated thrombosis and may represent targets for diagnosis and intervention. We suggest that the preponderance of PDPN expression as a risk factor in glioblastoma and the involvement of platelets may merit investigating anti-platelets for potential inclusion in thrombosis management in GBM.


2021 ◽  
Vol 10 (3) ◽  
pp. 109-120
Author(s):  
A. I. Mosiagina ◽  
A. V. Morgun ◽  
A. B. Salmina

There is growing research focusing on endothelial cells as separate units of the blood-brain barrier (BBB), and on the complex relationships between different types of cells within a neurovascular unit. To conduct this type of studies, researches use vastly different in vitro BBB models. The main objective of such models is to study the BBB permeability for different molecules, and to advance the current level of understanding the mechanisms of disease and to develop methods of targeted therapy for the central nervous system. The analysis of the existing Abstract in vitro BBB models and their advantages/disadvantages was conducted using the clinical trial data obtained in Russian/foreign countries. In this review, the authors highlight the most relevant assessment parameters and propose a unified classification of in vitro BBB models. According to the performed analysis, there is a tendency to move from 2D BBB models based on semipermeable inserts to 3D BBB spheroid and microfluidic organ-on-chip models. Moreover, the use of human induced pluripotent stem cells instead of animal primary cells will make it possible to reliably scale the results obtained in vitro to conditions in vivo.


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