scholarly journals Non-codon Optimized PiggyBac Transposase Induces Developmental Brain Aberrations: A Call for in vivo Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Franziska Vierl ◽  
Manpreet Kaur ◽  
Magdalena Götz
Keyword(s):  
Viral Vectors ◽  
Radial Glia ◽  
Insert Size ◽  
Seamless Integration ◽  
Piggybac Transposon ◽  
Radial Glial Cells ◽  
Basal Progenitor ◽  
Function Expression ◽  
Fate Determinants

In this perspective article, we briefly review tools for stable gain-of-function expression to explore key fate determinants in embryonic brain development. As the piggyBac transposon system has the highest insert size, a seamless integration of the transposed sequence into the host genome, and can be delivered by transfection avoiding viral vectors causing an immune response, we explored its use in the murine developing forebrain. The original piggyBac transposase PBase or the mouse codon-optimized version mPB and the construct to insert, contained in the piggyBac transposon, were introduced by in utero electroporation at embryonic day 13 into radial glia, the neural stem cells, in the developing dorsal telencephalon, and analyzed 3 or 5 days later. When using PBase, we observed an increase in basal progenitor cells, often accompanied by folding aberrations. These effects were considerably ameliorated when using the piggyBac plasmid together with mPB. While size and strength of the electroporated region was not correlated to the aberrations, integration was essential and the positive correlation to the insert size implicates the frequency of transposition as a possible mechanism. We discuss this in light of the increase in transposing endogenous viral vectors during mammalian phylogeny and their role in neurogenesis and radial glial cells. Most importantly, we aim to alert the users of this system to the phenotypes caused by non-codon optimized PBase application in vivo.

Topical Review: Neuronal Migration in Cortical Development

2004 ◽  
Vol 19 (3) ◽  
pp. 274-279
Author(s):  
Shigeaki Kanatani ◽  
Hidenori Tabata ◽  
Kazunori Nakajima
Keyword(s):  
Neuronal Migration ◽  
Radial Glia ◽  
Asymmetric Cell Division ◽  
Time Lapse ◽  
Radial Glial Cells ◽  
Daughter Cells ◽  
Radial Glial ◽  
Time Lapse Imaging ◽  
Mitotic Behavior

Cortical formation in the developing brain is a highly complicated process involving neuronal production (through symmetric or asymmetric cell division) interaction of radial glia with neuronal migration, and multiple modes of neuronal migration. It has been convincingly demonstrated by numerous studies that radial glial cells are neural stem cells. However, the processes by which neurons arise from radial glia and migrate to their final destinations in vivo are not yet fully understood. Recent studies using time-lapse imaging of neuronal migration are giving investigators an increasingly more detailed understanding of the mitotic behavior of radial glia and the migrating behavior of their daughter cells. In this review, we describe recent progress in elucidating neuronal migration in brain formation and how neuronal migration is disturbed by mutations in genes that control this process. ( J Child Neurol 2005;20:274—279).

scholarly journals Directed Differentiation of Human Pluripotent Stem Cells into Radial Glia and Astrocytes Bypasses Neurogenesis

2021 ◽  
Author(s):  
Vukasin M. Jovanovic ◽  
Claire Malley ◽  
Carlos A. Tristan ◽  
Seungmi Ryu ◽  
Pei-Hsuan Chu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Pluripotent Stem Cells ◽  
Radial Glia ◽  
Human Pluripotent Stem Cells ◽  
Alexander Disease ◽  
Radial Glial Cells ◽  
Neural Lineage ◽  
Astrocyte Differentiation

AbstractDerivation of astrocytes from human pluripotent stem cells (hPSCs) is inefficient and cumbersome, impeding their use in biomedical research. Here, we developed a highly efficient chemically defined astrocyte differentiation strategy that overcomes current limitations. This approach largely bypasses neurogenesis, which otherwise precedes astrogliogenesis during brain development and in vitro experiments. hPSCs were first differentiated into radial glial cells (RGCs) exhibiting in vivo-like radial glia signatures. Activation of NOTCH and JAK/STAT pathways in bona fide RGCs resulted in direct astrogliogenesis confirmed by expression of various glial markers (NFIA, NFIB, SOX9, CD44, S100B, GFAP). Transcriptomic and genome-wide epigenetic analyses confirmed RGC-to-astrocyte differentiation and absence of neurogenesis. The morphological and functional identity of hPSC-derived astrocytes was confirmed by using an array of methods (e.g. electron microscopy, calcium imaging, co-culture with neurons, grafting into mouse brains). Lastly, the scalable protocol was adapted to a robotic platform and used to model Alexander disease. In conclusion, our findings uncover remarkable plasticity in neural lineage progression that can be exploited to manufacture large numbers of human hPSC-derived astrocytes for drug development and regenerative medicine.

scholarly journals Transcriptional priming as a conserved mechanism of lineage diversification in the developing mouse and human neocortex

2020 ◽  
Vol 6 (45) ◽  
pp. eabd2068
Author(s):  
Zhen Li ◽  
William A. Tyler ◽  
Ella Zeldich ◽  
Gabriel Santpere Baró ◽  
Mayumi Okamoto ◽  
...  
Keyword(s):  
Glial Cells ◽  
Radial Glia ◽  
Radial Glial Cells ◽  
Human Neocortex ◽  
Intermediate Progenitors ◽  
Cell Diversity ◽  
Radial Glial ◽  
The Rich ◽  
Lineage Diversification

How the rich variety of neurons in the nervous system arises from neural stem cells is not well understood. Using single-cell RNA-sequencing and in vivo confirmation, we uncover previously unrecognized neural stem and progenitor cell diversity within the fetal mouse and human neocortex, including multiple types of radial glia and intermediate progenitors. We also observed that transcriptional priming underlies the diversification of a subset of ventricular radial glial cells in both species; genetic fate mapping confirms that the primed radial glial cells generate specific types of basal progenitors and neurons. The different precursor lineages therefore diversify streams of cell production in the developing murine and human neocortex. These data show that transcriptional priming is likely a conserved mechanism of mammalian neural precursor lineage specialization.

The Synergy between CRISPR and Chemical Engineering

2019 ◽  
Vol 19 (3) ◽  
pp. 147-171
Author(s):  
Cia-Hin Lau ◽  
Chung Tin
Keyword(s):  
Viral Vectors ◽  
Chemical Engineering ◽  
Target Genes ◽  
New Technologies ◽  
Rapid Development ◽  
Genetic Circuits ◽  
Viral Packaging ◽  
Conditional Control ◽  
Logic Operations

Gene therapy and transgenic research have advanced quickly in recent years due to the development of CRISPR technology. The rapid development of CRISPR technology has been largely benefited by chemical engineering. Firstly, chemical or synthetic substance enables spatiotemporal and conditional control of Cas9 or dCas9 activities. It prevents the leaky expression of CRISPR components, as well as minimizes toxicity and off-target effects. Multi-input logic operations and complex genetic circuits can also be implemented via multiplexed and orthogonal regulation of target genes. Secondly, rational chemical modifications to the sgRNA enhance gene editing efficiency and specificity by improving sgRNA stability and binding affinity to on-target genomic loci, and hence reducing off-target mismatches and systemic immunogenicity. Chemically-modified Cas9 mRNA is also more active and less immunogenic than the native mRNA. Thirdly, nonviral vehicles can circumvent the challenges associated with viral packaging and production through the delivery of Cas9-sgRNA ribonucleoprotein complex or large Cas9 expression plasmids. Multi-functional nanovectors enhance genome editing in vivo by overcoming multiple physiological barriers, enabling ligand-targeted cellular uptake, and blood-brain barrier crossing. Chemical engineering can also facilitate viral-based delivery by improving vector internalization, allowing tissue-specific transgene expression, and preventing inactivation of the viral vectors in vivo. This review aims to discuss how chemical engineering has helped improve existing CRISPR applications and enable new technologies for biomedical research. The usefulness, advantages, and molecular action for each chemical engineering approach are also highlighted.

Non-Viral Vectors for Gene Delivery

2018 ◽  
Vol 9 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Aparna Bansal ◽  
Himanshu
Keyword(s):  
Gene Therapy ◽  
Viral Vectors ◽  
Transfection Efficiency ◽  
Gene Transfection ◽  
Expression System ◽  
Target Cells ◽  
Specific Expression ◽  
Naked Dna

Introduction: Gene therapy has emerged out as a promising therapeutic pave for the treatment of genetic and acquired diseases. Gene transfection into target cells using naked DNA is a simple and safe approach which has been further improved by combining vectors or gene carriers. Both viral and non-viral approaches have achieved a milestone to establish this technique, but non-viral approaches have attained a significant attention because of their favourable properties like less immunotoxicity and biosafety, easy to produce with versatile surface modifications, etc. Literature is rich in evidences which revealed that undoubtedly, non–viral vectors have acquired a unique place in gene therapy but still there are number of challenges which are to be overcome to increase their effectiveness and prove them ideal gene vectors. Conclusion: To date, tissue specific expression, long lasting gene expression system, enhanced gene transfection efficiency has been achieved with improvement in delivery methods using non-viral vectors. This review mainly summarizes the various physical and chemical methods for gene transfer in vitro and in vivo.

scholarly journals Generation of tetracycline-controllable CYP3A4-expressing Caco-2 cells by the piggyBac transposon system

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Moe Ichikawa ◽  
Hiroki Akamine ◽  
Michika Murata ◽  
Sumito Ito ◽  
Kazuo Takayama ◽  
...  
Keyword(s):  
Small Intestine ◽  
Drug Absorption ◽  
Cell Model ◽  
Negative Effects ◽  
Piggybac Transposon ◽  
Drug Metabolizing Enzyme ◽  
Metabolizing Enzyme ◽  
Cyp3a4 Expression

AbstractCaco-2 cells are widely used as an in vitro intestinal epithelial cell model because they can form a monolayer and predict drug absorption with high accuracy. However, Caco-2 cells hardly express cytochrome P450 (CYP), a drug-metabolizing enzyme. It is known that CYP3A4 is the dominant drug-metabolizing enzyme in human small intestine. In this study, we generated CYP3A4-expressing Caco-2 (CYP3A4-Caco-2) cells and attempted to establish a model that can simultaneously evaluate drug absorption and metabolism. CYP3A4-Caco-2 cells were generated by piggyBac transposon vectors. A tetracycline-controllable CYP3A4 expression cassette (tet-on system) was stably transduced into Caco-2 cells, thus regulating the levels of CYP3A4 expression depending on the doxycycline concentration. The CYP3A4 expression levels in CYP3A4-Caco-2 cells cultured in the presence of doxycycline were similar to or higher than those of adult small intestine. The CYP3A4-Caco-2 cells had enough ability to metabolize midazolam, a substrate of CYP3A4. CYP3A4 overexpression had no negative effects on cell proliferation, barrier function, and P-glycoprotein activity in Caco-2 cells. Thus, we succeeded in establishing Caco-2 cells with CYP3A4 metabolizing activity comparable to in vivo human intestinal tissue. This cell line would be useful in pharmaceutical studies as a model that can simultaneously evaluate drug absorption and metabolism.

Highly efficient cell-mediated gene transfer using non-viral vectors and FuGene™6: in vitro and in vivo studies

2000 ◽  
Vol 57 (8) ◽  
pp. 1326-1333 ◽  
Author(s):  
I. Hellgren* ◽  
V. Drvota ◽  
R. Pieper ◽  
S. Enoksson ◽  
P. Blomberg ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Viral Vectors ◽  
In Vivo Studies ◽  
Highly Efficient

scholarly journals Seamless integration of bioelectronic interface in an animal model via in vivo polymerization of conjugated oligomers

2021 ◽  
Author(s):  
Giuseppina Tommasini ◽  
Gwennaël Dufil ◽  
Federica Fardella ◽  
Xenofon Strakosas ◽  
Eugenio Fergola ◽  
...  
Keyword(s):  
Animal Model ◽  
Conjugated Oligomers ◽  
Seamless Integration

scholarly journals Tissue-Specific Transcriptional Targeting of a Replication-Competent Retroviral Vector

2002 ◽  
Vol 76 (24) ◽  
pp. 12783-12791 ◽  
Author(s):  
Christopher R. Logg ◽  
Aki Logg ◽  
Robert J. Matusik ◽  
Bernard H. Bochner ◽  
Noriyuki Kasahara
Keyword(s):  
Tumor Cells ◽  
Viral Vectors ◽  
High Efficiency ◽  
Leukemia Virus ◽  
Transduction Efficiency ◽  
Promoter Strength ◽  
Cell Type ◽  
Cell Type Specificity ◽  
Tissue Specific

ABSTRACT The inability of replication-defective viral vectors to efficiently transduce tumor cells in vivo has prevented the successful application of such vectors in gene therapy of cancer. To address the need for more efficient gene delivery systems, we have developed replication-competent retroviral (RCR) vectors based on murine leukemia virus (MLV). We have previously shown that such vectors are capable of transducing solid tumors in vivo with very high efficiency. While the natural requirement of MLV infection for cell division imparts a certain degree of specificity for tumor cells, additional means for confining RCR vector replication to tumor cells are desirable. Here, we investigated the parameters critical for successful tissue-specific transcriptional control of RCR vector replication by replacing various lengths of the MLV enhancer/promoter with sequences derived either from the highly prostate-specific probasin (PB) promoter or from a more potent synthetic variant of the PB promoter. We assessed the transcriptional specificity of the resulting hybrid long terminal repeats (LTRs) and the cell type specificity and efficiency of replication of vectors containing these LTRs. Incorporation of PB promoter sequences effectively restricted transcription from the LTR to prostate-derived cells and imparted prostate-specific RCR vector replication but required the stronger synthetic promoter and retention of native MLV sequences in the vicinity of the TATA box for optimal replicative efficiency and specificity. Our results have thus identified promoter strength and positioning within the LTR as important determinants for achieving both high transduction efficiency and strict cell type specificity in transcriptionally targeted RCR vectors.

Inherent hepatocytic heterogeneity determines expression and retention of edited F9 alleles post-AAV/CRISPR infusion

2021 ◽  
Vol 118 (42) ◽  
pp. e2110887118
Author(s):  
Qiang Wang ◽  
Lin Zhang ◽  
Guo-Wei Zhang ◽  
Jian-Hua Mao ◽  
Xiao-Dong Xi ◽  
...  
Keyword(s):  
Viral Vectors ◽  
Gene Editing ◽  
Regulatory Region ◽  
Factor Ix ◽  
Host Cells ◽  
Clotting Factor ◽  
Dependent Manner ◽  
Coding Region ◽  
Therapeutic Benefits

Infusing CRISPR/donor-loaded adeno-associated viral vectors (AAV/CRISPR) could enable in vivo hepatic gene editing to remedy hemophilia B (HB) with inherited deficiency of clotting factor IX (FIX). Yet, current regimens focus on correcting HB with simple mutations in the coding region of the F9, overlooking those carrying complicated mutations involving the regulatory region. Moreover, a possible adverse effect of treatment-related inflammation remains unaddressed. Here we report that a single DNA cutting-mediated long-range replacement restored the FIX-encoding function of a mutant F9 (mF9) carrying both regulatory and coding defects in a severe mouse HB model, wherein incorporation of a synthetic Alb enhancer/promoter-mimic (P2) ensured FIX elevation to clinically meaningful levels. Through single-cell RNA sequencing (scRNA-seq) of liver tissues, we revealed that a subclinical hepatic inflammation post-AAV/CRISPR administration regulated the vulnerability of the edited mF9-harboring host cells to cytotoxic T lymphocytes (CTLs) and the P2 activity in a hepatocytic subset–dependent manner via modulating specific sets of liver-enriched transcription factors (LETFs). Collectively, our study establishes an AAV/CRISPR-mediated gene-editing protocol applicable to complicated monogenetic disorders, underscoring the potentiality of improving therapeutic benefits through managing inflammation.

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