scholarly journals Human iPSC-derived astrocytes transplanted into the mouse brain undergo morphological changes in response to amyloid-β plaques

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Pranav Preman ◽  
Julia TCW ◽  
Sara Calafate ◽  
An Snellinx ◽  
Maria Alfonso-Triguero ◽  
...  

Abstract Background Increasing evidence for a direct contribution of astrocytes to neuroinflammatory and neurodegenerative processes causing Alzheimer’s disease comes from molecular and functional studies in rodent models. However, these models may not fully recapitulate human disease as human and rodent astrocytes differ considerably in morphology, functionality, and gene expression. Results To address these challenges, we established an approach to study human astrocytes within the mouse brain by transplanting human induced pluripotent stem cell (hiPSC)-derived astrocyte progenitors into neonatal brains. Xenografted hiPSC-derived astrocyte progenitors differentiated into astrocytes that integrated functionally within the mouse host brain and matured in a cell-autonomous way retaining human-specific morphologies, unique features, and physiological properties. In Alzheimer´s chimeric brains, transplanted hiPSC-derived astrocytes responded to the presence of amyloid plaques undergoing morphological changes that seemed independent of the APOE allelic background. Conclusions In sum, we describe here a promising approach that consist of transplanting patient-derived and genetically modified astrocytes into the mouse brain to study human astrocyte pathophysiology in the context of Alzheimer´s disease.

2020 ◽  
Author(s):  
Pranav Preman ◽  
Julia TCW ◽  
Sara Calafate ◽  
An Snellinx ◽  
Maria Alfonso-Triguero ◽  
...  

ABSTRACTBackgroundIncreasing evidence for a direct contribution of astrocytes to neuroinflammatory and neurodegenerative processes causing Alzheimer’s disease comes from molecular studies in rodent models. However, these models may not fully recapitulate human disease as human and rodent astrocytes differ considerably in morphology, functionality, and gene expression.MethodsTo address these challenges, we established an approach to study human astroglia within the context of the mouse brain by transplanting human induced pluripotent stem cell (hiPSC)-derived glia progenitors into neonatal brains of immunodeficient mice.ResultsXenografted (hiPSC)-derived glia progenitors differentiate into astrocytes that integrate functionally within the mouse host brain and mature in a cell-autonomous way retaining human-specific morphologies, unique features and physiological properties. In Alzheimer’s chimeric brains, transplanted hiPSC-derived astrocytes respond to the presence of amyloid plaques with various morphological changes that seem independent of the APOE allelic background.ConclusionIn sum, this chimeric model has great potential to analyze the role of patient-derived and genetically modified astroglia in Alzheimer’s disease.


2020 ◽  
Author(s):  
Pranav Preman ◽  
Julia TCW ◽  
Sara Calafate ◽  
An Snellinx ◽  
Maria Alfonso-Triguero ◽  
...  

Abstract Background: Increasing evidence for a direct contribution of astrocytes to neuroinflammatory and neurodegenerative processes causing Alzheimer’s disease comes from molecular studies in rodent models. However, these models may not fully recapitulate human disease as human and rodent astrocytes differ considerably in morphology, functionality, and gene expression. Methods: To address these challenges, we established an approach to study human astroglia within the context of the mouse brain by transplanting human induced pluripotent stem cell (hiPSC)-derived glia progenitors into neonatal brains of immunodeficient mice. Results: Xenografted (hiPSC)-derived glia progenitors differentiate into astrocytes that integrate functionally within the mouse host brain and mature in a cell-autonomous way retaining human-specific morphologies, unique features and physiological properties. In Alzheimer´s chimeric brains, transplanted hiPSC-derived astrocytes respond to the presence of amyloid plaques with various morphological changes that seem independent of the APOE allelic background. Conclusion: In sum, this chimeric model has great potential to analyze the role of patient-derived and genetically modified astroglia in Alzheimer’s disease. Keywords: human induced pluripotent stem cells (hiPSCs), astrocytes, chimeric mouse models, Alzheimer’s disease, amyloid plaques, APOE


2017 ◽  
Vol 312 (6) ◽  
pp. H1144-H1153 ◽  
Author(s):  
Sam Chai ◽  
Xiaoping Wan ◽  
Drew M. Nassal ◽  
Haiyan Liu ◽  
Christine S. Moravec ◽  
...  

Two-pore K+ (K2p) channels have been described in modulating background conductance as leak channels in different physiological systems. In the heart, the expression of K2p channels is heterogeneous with equivocation regarding their functional role. Our objective was to determine the K2p expression profile and their physiological and pathophysiological contribution to cardiac electrophysiology. Induced pluripotent stem cells (iPSCs) generated from humans were differentiated into cardiomyocytes (iPSC-CMs). mRNA was isolated from these cells, commercial iPSC-CM (iCells), control human heart ventricular tissue (cHVT), and ischemic (iHF) and nonischemic heart failure tissues (niHF). We detected 10 K2p channels in the heart. Comparing quantitative PCR expression of K2p channels between human heart tissue and iPSC-CMs revealed K2p1.1, K2p2.1, K2p5.1, and K2p17.1 to be higher expressed in cHVT, whereas K2p3.1 and K2p13.1 were higher in iPSC-CMs. Notably, K2p17.1 was significantly lower in niHF tissues compared with cHVT. Action potential recordings in iCells after K2p small interfering RNA knockdown revealed prolongations in action potential depolarization at 90% repolarization for K2p2.1, K2p3.1, K2p6.1, and K2p17.1. Here, we report the expression level of 10 human K2p channels in iPSC-CMs and how they compared with cHVT. Importantly, our functional electrophysiological data in human iPSC-CMs revealed a prominent role in cardiac ventricular repolarization for four of these channels. Finally, we also identified K2p17.1 as significantly reduced in niHF tissues and K2p4.1 as reduced in niHF compared with iHF. Thus, we advance the notion that K2p channels are emerging as novel players in cardiac ventricular electrophysiology that could also be remodeled in cardiac pathology and therefore contribute to arrhythmias. NEW & NOTEWORTHY Two-pore K+ (K2p) channels are traditionally regarded as merely background leak channels in myriad physiological systems. Here, we describe the expression profile of K2p channels in human-induced pluripotent stem cell-derived cardiomyocytes and outline a salient role in cardiac repolarization and pathology for multiple K2p channels.


2021 ◽  
Vol 14 ◽  
Author(s):  
Jacob B. Ruden ◽  
Mrinalini Dixit ◽  
José C. Zepeda ◽  
Brad A. Grueter ◽  
Laura L. Dugan

N-methyl-D-aspartate (NMDA) receptors are critical for higher-order nervous system function, but in previously published protocols to convert human induced pluripotent stem cells (iPSCs) to mature neurons, functional NMDA receptors (NMDARs) are often either not reported or take an extended time to develop. Here, we describe a protocol to convert human iPSC-derived neural progenitor cells (NPCs) to mature neurons in only 37 days. We demonstrate that the mature neurons express functional NMDARs exhibiting ligand-activated calcium flux, and we document the presence of NMDAR-mediated electrically evoked postsynaptic current. In addition to being more rapid than previous procedures, our protocol is straightforward, does not produce organoids which are difficult to image, and does not involve co-culture with rodent astrocytes. This could enhance our ability to study primate/human-specific aspects of NMDAR function and signaling in health and disease.


2018 ◽  
Vol 24 (10) ◽  
pp. 605-615 ◽  
Author(s):  
Katsuhisa Matsuura ◽  
Kyoji Ito ◽  
Nobuaki Shiraki ◽  
Shoen Kume ◽  
Nobuhisa Hagiwara ◽  
...  

2018 ◽  
Author(s):  
Bogdan A Mirauta ◽  
Daniel D Seaton ◽  
Dalila Bensaddek ◽  
Alejandro Brenes ◽  
Marc J Bonder ◽  
...  

AbstractRealising the potential of human induced pluripotent stem cell (iPSC) technology for drug discovery, disease modelling and cell therapy requires an understanding of variability across iPSC lines. While previous studies have characterized iPS cell lines genetically and transcriptionally, little is known about the variability of the iPSC proteome. Here, we present the first comprehensive proteomic iPSC dataset, analysing 202 iPSC lines derived from 151 donors. We characterise the major genetic determinants affecting proteome and transcriptome variation across iPSC lines and identify key regulatory mechanisms affecting variation in protein abundance. Our data identified >700 human iPSC protein quantitative trait loci (pQTLs). We mapped trans regulatory effects, identifying an important role for protein-protein interactions. We discovered that pQTLs show increased enrichment in disease-linked GWAS variants, compared with RNA-based eQTLs.


2021 ◽  
Author(s):  
Qiyan Mao ◽  
Achyuth Acharya ◽  
Alejandra Rodriguez-delaRosa ◽  
Fabio Marchiano ◽  
Benoit Dehapiot ◽  
...  

Human muscle is a hierarchically organised tissue with its contractile cells called myofibers packed into large myofiber bundles. Each myofiber contains periodic myofibrils built by hundreds of contractile sarcomeres that generate large mechanical forces. To better understand the mechanisms that coordinate human muscle morphogenesis from tissue to molecular scales, we adopted a simple in vitro system using induced pluripotent stem cell-derived human myogenic precursors. When grown on an unrestricted two-dimensional substrate, developing myofibers spontaneously align and self-organise into higher-order myofiber bundles, which grow and consolidate to stable sizes. Following a transcriptional boost of sarcomeric components, myofibrils assemble into chains of periodic sarcomeres that emerge across the entire myofiber. By directly probing tension we found that tension build-up precedes sarcomere assembly and increases within each assembling myofibril. Furthermore, we found that myofiber ends stably attach to other myofibers using integrin-based attachments and thus myofiber bundling coincides with stable myofiber bundle attachment in vitro. A failure in stable myofiber attachment results in a collapse followed by a disassembly of the myofibrils. Overall, our results strongly suggest that mechanical tension across sarcomeric components as well as between differentiating myofibers is key to coordinate the multi-scale self-organisation of muscle morphogenesis.


2021 ◽  
Vol 118 (15) ◽  
pp. e2025847118
Author(s):  
Dorit Trudler ◽  
Kristopher L. Nazor ◽  
Yvonne S. Eisele ◽  
Titas Grabauskas ◽  
Nima Dolatabadi ◽  
...  

Parkinson’s disease is characterized by accumulation of α-synuclein (αSyn). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal death in part via microglial activation. Heretofore, it remained unknown if oligomeric/fibrillar αSyn could activate the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome in human microglia and whether anti-αSyn antibodies could prevent this effect. Here, we show that αSyn activates the NLRP3 inflammasome in human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) via dual stimulation involving Toll-like receptor 2 (TLR2) engagement and mitochondrial damage. In vitro, hiMG can be activated by mutant (A53T) αSyn secreted from hiPSC-derived A9-dopaminergic neurons. Surprisingly, αSyn–antibody complexes enhanced rather than suppressed inflammasome-mediated interleukin-1β (IL-1β) secretion, indicating these complexes are neuroinflammatory in a human context. A further increase in inflammation was observed with addition of oligomerized amyloid-β peptide (Aβ) and its cognate antibody. In vivo, engraftment of hiMG with αSyn in humanized mouse brain resulted in caspase-1 activation and neurotoxicity, which was exacerbated by αSyn antibody. These findings may have important implications for antibody therapies aimed at depleting misfolded/aggregated proteins from the human brain, as they may paradoxically trigger inflammation in human microglia.


2020 ◽  
Vol 319 (5) ◽  
pp. H1112-H1122 ◽  
Author(s):  
Weizhen Li ◽  
Julie L. Han ◽  
Emilia Entcheva

We identify cell culture density and cell-cell contact as an important factor in determining the expression of a key ion channel at the transcriptional and the protein levels, KCNJ2/Kir2.1, and its contribution to the electrophysiology of human induced pluripotent stem cell-derived cardiomyocytes. Our results indicate that studies on isolated cells, out of tissue context, may underestimate the cellular ion channel properties being characterized.


2019 ◽  
Vol 20 (18) ◽  
pp. 4381 ◽  
Author(s):  
Andreas Brodehl ◽  
Hans Ebbinghaus ◽  
Marcus-André Deutsch ◽  
Jan Gummert ◽  
Anna Gärtner ◽  
...  

In the last few decades, many pathogenic or likely pathogenic genetic mutations in over hundred different genes have been described for non-ischemic, genetic cardiomyopathies. However, the functional knowledge about most of these mutations is still limited because the generation of adequate animal models is time-consuming and challenging. Therefore, human induced pluripotent stem cells (iPSCs) carrying specific cardiomyopathy-associated mutations are a promising alternative. Since the original discovery that pluripotency can be artificially induced by the expression of different transcription factors, various patient-specific-induced pluripotent stem cell lines have been generated to model non-ischemic, genetic cardiomyopathies in vitro. In this review, we describe the genetic landscape of non-ischemic, genetic cardiomyopathies and give an overview about different human iPSC lines, which have been developed for the disease modeling of inherited cardiomyopathies. We summarize different methods and protocols for the general differentiation of human iPSCs into cardiomyocytes. In addition, we describe methods and technologies to investigate functionally human iPSC-derived cardiomyocytes. Furthermore, we summarize novel genome editing approaches for the genetic manipulation of human iPSCs. This review provides an overview about the genetic landscape of inherited cardiomyopathies with a focus on iPSC technology, which might be of interest for clinicians and basic scientists interested in genetic cardiomyopathies.


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