scholarly journals Layered hydrogels accelerate iPSC-derived neuronal maturation and reveal migration defects caused by MeCP2 dysfunction

2016 ◽  
Vol 113 (12) ◽  
pp. 3185-3190 ◽  
Author(s):  
Zhen-Ning Zhang ◽  
Beatriz C. Freitas ◽  
Hao Qian ◽  
Jacques Lux ◽  
Allan Acab ◽  
...  
Keyword(s):  
Neurodevelopmental Disorders ◽  
Neural Progenitor Cells ◽  
Specific Effect ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Mechanical Stimuli ◽  
Wide Range ◽  
Cellular Phenotypes ◽  
The Brain

Probing a wide range of cellular phenotypes in neurodevelopmental disorders using patient-derived neural progenitor cells (NPCs) can be facilitated by 3D assays, as 2D systems cannot entirely recapitulate the arrangement of cells in the brain. Here, we developed a previously unidentified 3D migration and differentiation assay in layered hydrogels to examine how these processes are affected in neurodevelopmental disorders, such as Rett syndrome. Our soft 3D system mimics the brain environment and accelerates maturation of neurons from human induced pluripotent stem cell (iPSC)-derived NPCs, yielding electrophysiologically active neurons within just 3 wk. Using this platform, we revealed a genotype-specific effect of methyl-CpG-binding protein-2 (MeCP2) dysfunction on iPSC-derived neuronal migration and maturation (reduced neurite outgrowth and fewer synapses) in 3D layered hydrogels. Thus, this 3D system expands the range of neural phenotypes that can be studied in vitro to include those influenced by physical and mechanical stimuli or requiring specific arrangements of multiple cell types.

scholarly journals Application of Human Induced Pluripotent Stem Cell-Derived Cellular and Organoid Models for COVID-19 Research

2021 ◽  
Vol 9 ◽  
Author(s):  
Yumei Luo ◽  
Mimi Zhang ◽  
Yapei Chen ◽  
Yaoyong Chen ◽  
Detu Zhu
Keyword(s):  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Life Cycles ◽  
Global Public Health ◽  
Health Crisis ◽  
Infection Mechanisms ◽  
Induced Pluripotent ◽  
The Brain

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid international spread has caused the coronavirus disease 2019 (COVID-19) pandemics, which is a global public health crisis. Thus, there is an urgent need to establish biological models to study the pathology of SARS-CoV-2 infection, which not only involves respiratory failure, but also includes dysregulation of other organs and systems, including the brain, heart, liver, intestines, pancreas, kidneys, eyes, and so on. Cellular and organoid models derived from human induced pluripotent stem cells (iPSCs) are ideal tools for in vitro simulation of viral life cycles and drug screening to prevent the reemergence of coronavirus. These iPSC-derived models could recapitulate the functions and physiology of various human cell types and assemble the complex microenvironments similar with those in the human organs; therefore, they can improve the study efficiency of viral infection mechanisms, mimic the natural host-virus interaction, and be suited for long-term experiments. In this review, we focus on the application of in vitro iPSC-derived cellular and organoid models in COVID-19 studies.

The non-cell-autonomous component of ALS: new in vitro models and future challenges

2014 ◽  
Vol 42 (5) ◽  
pp. 1270-1274 ◽  
Author(s):  
Laura Ferraiuolo
Keyword(s):  
Motor Neurons ◽  
Neural Progenitor Cells ◽  
Neurodegenerative Disorder ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
In Vitro Models ◽  
Future Challenges ◽  
Induced Pluripotent ◽  
Als Patients

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disorder affecting the motor nerves. At present, there is no effective therapy for this devastating disease and only one Food and Drug Administration (FDA)-approved drug, riluzole, is known to moderately extend survival. In the last decade, the field of ALS has made a remarkable leap forward in understanding some of the genetic causes of this disease and the role that different cell types play in the degenerative mechanism affecting motor neurons. In particular, astrocytes have been implicated in disease progression, and multiple studies suggest that these cells are valuable therapeutic targets. Recent technological advancements have provided new tools to generate astrocytes from ALS patients either from post-mortem biopsies or from skin fibroblasts through genetic reprogramming. The advent of induced pluripotent stem cell (iPSC) technology and the newly developed induced neural progenitor cells (iNPCs) have created unprecedented exciting opportunities to unravel the mechanisms involved in neurodegeneration and initiate high-throughput drug screenings.

scholarly journals Microglia in Neurodegenerative Events—An Initiator or a Significant Other?

2021 ◽  
Vol 22 (11) ◽  
pp. 5818
Author(s):  
Gaylia Jean Harry
Keyword(s):  
Neurovascular Unit ◽  
Cell Types ◽  
In Vitro Assays ◽  
Significant Other ◽  
Neurodegenerative Process ◽  
Target Sites ◽  
Systemic Factors ◽  
Injury And Repair ◽  
The Brain

A change in microglia structure, signaling, or function is commonly associated with neurodegeneration. This is evident in the patient population, animal models, and targeted in vitro assays. While there is a clear association, it is not evident that microglia serve as an initiator of neurodegeneration. Rather, the dynamics imply a close interaction between the various cell types and structures in the brain that orchestrate the injury and repair responses. Communication between microglia and neurons contributes to the physiological phenotype of microglia maintaining cells in a surveillance state and allows the cells to respond to events occurring in their environment. Interactions between microglia and astrocytes is not as well characterized, nor are interactions with other members of the neurovascular unit; however, given the influence of systemic factors on neuroinflammation and disease progression, such interactions likely represent significant contributes to any neurodegenerative process. In addition, they offer multiple target sites/processes by which environmental exposures could contribute to neurodegenerative disease. Thus, microglia at least play a role as a significant other with an equal partnership; however, claiming a role as an initiator of neurodegeneration remains somewhat controversial.

scholarly journals Human iPSC-Based Modeling of Central Nerve System Disorders for Drug Discovery

2021 ◽  
Vol 22 (3) ◽  
pp. 1203
Author(s):  
Lu Qian ◽  
Julia TCW
Keyword(s):  
Drug Discovery ◽  
Disease Modeling ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Central Nerve System ◽  
Human Ipscs ◽  
Nerve System

A high-throughput drug screen identifies potentially promising therapeutics for clinical trials. However, limitations that persist in current disease modeling with limited physiological relevancy of human patients skew drug responses, hamper translation of clinical efficacy, and contribute to high clinical attritions. The emergence of induced pluripotent stem cell (iPSC) technology revolutionizes the paradigm of drug discovery. In particular, iPSC-based three-dimensional (3D) tissue engineering that appears as a promising vehicle of in vitro disease modeling provides more sophisticated tissue architectures and micro-environmental cues than a traditional two-dimensional (2D) culture. Here we discuss 3D based organoids/spheroids that construct the advanced modeling with evolved structural complexity, which propels drug discovery by exhibiting more human specific and diverse pathologies that are not perceived in 2D or animal models. We will then focus on various central nerve system (CNS) disease modeling using human iPSCs, leading to uncovering disease pathogenesis that guides the development of therapeutic strategies. Finally, we will address new opportunities of iPSC-assisted drug discovery with multi-disciplinary approaches from bioengineering to Omics technology. Despite technological challenges, iPSC-derived cytoarchitectures through interactions of diverse cell types mimic patients’ CNS and serve as a platform for therapeutic development and personalized precision medicine.

Df31 is a novel nuclear protein involved in chromatin structure in Drosophila melanogaster

2001 ◽  
Vol 114 (1) ◽  
pp. 37-47 ◽  
Author(s):  
G. Crevel ◽  
H. Huikeshoven ◽  
S. Cotterill
Keyword(s):  
Cell Types ◽  
Drosophila Embryo ◽  
Cell Fractionation ◽  
General Function ◽  
Structural Protein ◽  
Chromosomal Structure ◽  
Binding Characteristics ◽  
Wide Range ◽  
Cellular Dna

We originally isolated the Df31 protein from Drosophila embryo extracts as a factor which could decondense Xenopus sperm, by removing the sperm specific proteins and interacting with histones to facilitate their loading onto DNA. We now believe that this protein has a more general function in cellular DNA metabolism. The Df31 gene encodes a very hydrophilic protein with a predicted molecular mass of 18.5 kDa. Immunostaining showed that Df31 was present in a wide range of cell types throughout differentiation and in both dividing and non-dividing cells. In all cases the protein is present in large amounts, comparable with the level of nucleosomes. Injection of antisense oligonucleotides to lower the level of Df31 in embryos caused severe disruption of the nuclear structure. Large irregular clumps of DNA were formed, and in most cases the amount of DNA associated with each clump was more than that found in a normal nucleus. Immunofluorescence, cell fractionation, and formaldehyde cross-linking show that Df31 is associated with chromatin and that a significant fraction of it binds very tightly. It also shows the same binding characteristics when loaded onto chromatin in vitro. Chromatin fractionation shows that Df31 is tightly associated with nucleosomes, preferentially with oligonucleosomes. Despite this no differences were observed in the properties of nucleosomes loaded in the in vitro system in the presence and absence of Df31. These results suggest that Df31 has a role in chromosomal structure, most likely acting as a structural protein at levels of folding higher than that of nucleosomes.

scholarly journals Establishment of a Human Induced Pluripotent Stem Cell-Derived Neuromuscular Co-Culture Under Optogenetic Control

2020 ◽  
Author(s):  
Elliot W. Swartz ◽  
Greg Shintani ◽  
Jijun Wan ◽  
Joseph S. Maffei ◽  
Sarah H. Wang ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Calcium Flux ◽  
Electrode Arrays ◽  
Spinal Motor Neurons ◽  
Culture Model ◽  
Skeletal Myotubes ◽  
Induced Pluripotent

SummaryThe failure of the neuromuscular junction (NMJ) is a key component of degenerative neuromuscular disease, yet how NMJs degenerate in disease is unclear. Human induced pluripotent stem cells (hiPSCs) offer the ability to model disease via differentiation toward affected cell types, however, the re-creation of an in vitro neuromuscular system has proven challenging. Here we present a scalable, all-hiPSC-derived co-culture system composed of independently derived spinal motor neurons (MNs) and skeletal myotubes (sKM). In a model of C9orf72-associated disease, co-cultures form functional NMJs that can be manipulated through optical stimulation, eliciting muscle contraction and measurable calcium flux in innervated sKM. Furthermore, co-cultures grown on multi-electrode arrays (MEAs) permit the pharmacological interrogation of neuromuscular physiology. Utilization of this co-culture model as a tunable, patient-derived system may offer significant insights into NMJ formation, maturation, repair, or pathogenic mechanisms that underlie NMJ dysfunction in disease.

scholarly journals Two peptides targeting endothelial receptors are internalized into murine brain endothelial cells

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249686
Author(s):  
Diána Hudecz ◽  
Sara Björk Sigurdardóttir ◽  
Sarah Christine Christensen ◽  
Casper Hempel ◽  
Andrew J. Urquhart ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transferrin Receptor ◽  
Vesicular Transport ◽  
Brain Diseases ◽  
Brain Endothelial Cells ◽  
Binding Studies ◽  
Wide Range ◽  
Murine Brain ◽  
The Brain

The blood-brain barrier (BBB) is one of the main obstacles for therapies targeting brain diseases. Most macromolecules fail to pass the tight BBB, formed by brain endothelial cells interlinked by tight junctions. A wide range of small, lipid-soluble molecules can enter the brain parenchyma via diffusion, whereas macromolecules have to transcytose via vesicular transport. Vesicular transport can thus be utilized as a strategy to deliver brain therapies. By conjugating BBB targeting antibodies and peptides to therapeutic molecules or nanoparticles, it is possible to increase uptake into the brain. Previously, the synthetic peptide GYR and a peptide derived from melanotransferrin (MTfp) have been suggested as candidates for mediating transcytosis in brain endothelial cells (BECs). Here we study uptake, intracellular trafficking, and translocation of these two peptides in BECs. The peptides were synthesized, and binding studies to purified endocytic receptors were performed using surface plasmon resonance. Furthermore, the peptides were conjugated to a fluorophore allowing for live-cell imaging studies of their uptake into murine brain endothelial cells. Both peptides bound to low-density lipoprotein receptor-related protein 1 (LRP-1) and the human transferrin receptor, while lower affinity was observed against the murine transferrin receptor. The MTfp showed a higher binding affinity to all receptors when compared to the GYR peptide. The peptides were internalized by the bEnd.3 mouse endothelial cells within 30 min of incubation and frequently co-localized with endo-lysosomal vesicles. Moreover, our in vitro Transwell translocation experiments confirmed that GYR was able to cross the murine barrier and indicated the successful translocation of MTfp. Thus, despite binding to endocytic receptors with different affinities, both peptides are able to transcytose across the murine BECs.

scholarly journals CellMap: Characterizing the types and composition of iPSC-derived cells from RNA-seq data

2021 ◽  
Author(s):  
Zhengyu Ouyang ◽  
Nathanael Bourgeois ◽  
Eugenia Lyashenko ◽  
Paige Cundiff ◽  
Patrick F Cullen ◽  
...  
Keyword(s):  
Single Cell ◽  
Induced Pluripotent Stem Cell ◽  
Cell Types ◽  
Model Systems ◽  
Rna Seq ◽  
Cell Type ◽  
Fine Grained ◽  
Single Nucleus ◽  
Induced Pluripotent

Induced pluripotent stem cell (iPSC) derived cell types are increasingly employed as in vitro model systems for drug discovery. For these studies to be meaningful, it is important to understand the reproducibility of the iPSC-derived cultures and their similarity to equivalent endogenous cell types. Single-cell and single-nucleus RNA sequencing (RNA-seq) are useful to gain such understanding, but they are expensive and time consuming, while bulk RNA-seq data can be generated quicker and at lower cost. In silico cell type decomposition is an efficient, inexpensive, and convenient alternative that can leverage bulk RNA-seq to derive more fine-grained information about these cultures. We developed CellMap, a computational tool that derives cell type profiles from publicly available single-cell and single-nucleus datasets to infer cell types in bulk RNA-seq data from iPSC-derived cell lines.

scholarly journals Development of an LDL Receptor-Targeted Peptide Susceptible to Facilitate the Brain Access of Diagnostic or Therapeutic Agents

Biology ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 161
Author(s):  
Séverine André ◽  
Lionel Larbanoix ◽  
Sébastien Verteneuil ◽  
Dimitri Stanicki ◽  
Denis Nonclercq ◽  
...  
Keyword(s):  
Ldl Receptor ◽  
Density Lipoprotein ◽  
Therapeutic Agents ◽  
In Vivo Studies ◽  
Phage Display Technology ◽  
Brain Penetration ◽  
Wide Range ◽  
The Brain

Blood-brain barrier (BBB) crossing and brain penetration are really challenging for the delivery of therapeutic agents and imaging probes. The development of new crossing strategies is needed, and a wide range of approaches (invasive or not) have been proposed so far. The receptor-mediated transcytosis is an attractive mechanism, allowing the non-invasive penetration of the BBB. Among available targets, the low-density lipoprotein (LDL) receptor (LDLR) shows favorable characteristics mainly because of the lysosome-bypassed pathway of LDL delivery to the brain, allowing an intact discharge of the carried ligand to the brain targets. The phage display technology was employed to identify a dodecapeptide targeted to the extracellular domain of LDLR (ED-LDLR). This peptide was able to bind the ED-LDLR in the presence of natural ligands and dissociated at acidic pH and in the absence of calcium, in a similar manner as the LDL. In vitro, our peptide was endocytosed by endothelial cells through the caveolae-dependent pathway, proper to the LDLR route in BBB, suggesting the prevention of its lysosomal degradation. The in vivo studies performed by magnetic resonance imaging and fluorescent lifetime imaging suggested the brain penetration of this ED-LDLR-targeted peptide.

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