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Journal of Alzheimer's Disease : JAD 2022Alzheimer's disease (AD) is a neurodegenerative disease characterized by the accumulation of amyloid-β (Aβ) peptide in the brain.
BACKGROUND
Alzheimer's disease (AD) is a neurodegenerative disease characterized by the accumulation of amyloid-β (Aβ) peptide in the brain.
OBJECTIVE
To gain a better insight into alterations in major biochemical pathways underlying AD.
METHODS
We compared metabolomic profiles of hippocampal tissue of 20-month-old female Tg2576 mice expressing the familial AD-associated hAPP695SW transgene with their 20-month-old wild type female littermates.
RESULTS
The hAPP695SW transgene causes overproduction and accumulation of Aβ in the brain. Out of 180 annotated metabolites, 54 metabolites differed (30 higher and 24 lower in Tg2576 versus wild-type hippocampal tissue) and were linked to the amino acid, nucleic acid, glycerophospholipid, ceramide, and fatty acid metabolism. Our results point to 1) heightened metabolic activity as indicated by higher levels of urea, enhanced fatty acid β-oxidation, and lower fatty acid levels; 2) enhanced redox regulation; and 3) an imbalance of neuro-excitatory and neuro-inhibitory metabolites in hippocampal tissue of aged hAPP695SW transgenic mice.
CONCLUSION
Taken together, our results suggest that dysregulation of multiple metabolic pathways associated with a concomitant shift to an excitatory-inhibitory imbalance are contributing mechanisms of AD-related pathology in the Tg2576 mouse.
Topics: Aged; Alzheimer Disease; Amyloid beta-Peptides; Animals; Brain; Disease Models, Animal; Female; Hippocampus; Humans; Metabolomics; Mice; Mice, Transgenic; Signal Transduction; Transgenes
PubMed: 34958022
DOI: 10.3233/JAD-215084 -
Plant Biotechnology Journal Aug 2013The advances of modern plant technologies, especially genetically modified crops, are considered to be a substantial benefit to agriculture and society. However,... (Review)
Review
The advances of modern plant technologies, especially genetically modified crops, are considered to be a substantial benefit to agriculture and society. However, so-called transgene escape remains and is of environmental and regulatory concern. Genetic use restriction technologies (GURTs) provide a possible solution to prevent transgene dispersal. Although GURTs were originally developed as a way for intellectual property protection (IPP), we believe their maximum benefit could be in the prevention of gene flow, that is, bioconfinement. This review describes the underlying signal transduction and components necessary to implement any GURT system. Furthermore, we review the similarities and differences between IPP- and bioconfinement-oriented GURTs, discuss the GURTs' design for impeding transgene escape and summarize recent advances. Lastly, we go beyond the state of the science to speculate on regulatory and ecological effects of implementing GURTs for bioconfinement.
Topics: Genetic Techniques; Plants; Plants, Genetically Modified; Transgenes
PubMed: 23730743
DOI: 10.1111/pbi.12084 -
Molecular Therapy : the Journal of the... Oct 2006
Topics: Animals; Genetic Therapy; Genetic Vectors; Humans; Mutagenesis; Transgenes
PubMed: 16920032
DOI: 10.1016/j.ymthe.2006.08.002 -
Drug News & Perspectives May 2007Nonviral-mediated gene transfer was used in human gene therapy clinical trials that dealt with the treatment of inherited or acquired genetic disorders and cancer.... (Review)
Review
Nonviral-mediated gene transfer was used in human gene therapy clinical trials that dealt with the treatment of inherited or acquired genetic disorders and cancer. Several preclinical studies are currently ongoing to employ nonviral vectors in genetic immunization programs for a variety of infectious diseases. The interest in nonviral-mediated gene transfer is motivated by two main reasons: (I) nonviral-based vectors do not derive from infectious agents and are minimally toxic; and (II) they can be easily produced in large quantities. However, the main drawbacks of nonviral-mediated gene transfer are related to low transfection efficiency of target cells, especially in vivo, and to the transient nature of transgene expression. These drawbacks render nonviral-mediated gene transfer not particularly suitable for the treatment of pathological conditions that require long-term transgene expression, such as neurodegenerative disorders and inherited or acquired genetic diseases. On these grounds, the optimal application of nonviral-mediated gene transfer is in immunotherapy for cancer and infectious diseases, as a transient expression of the transgene might be sufficient to trigger effective and durable host immune responses. The purpose of this review is to summarize the standpoint of nonviral vector development.
Topics: Animals; DNA; Drug Delivery Systems; Gene Transfer Techniques; Genetic Vectors; Humans; Transgenes
PubMed: 17637935
DOI: 10.1358/dnp.2007.20.4.1103528 -
Life Science Alliance Jun 2023Precise determination of transgene zygosity is essential for use of transgenic mice in research. Because integration loci of transgenes are usually unknown due to their...
Precise determination of transgene zygosity is essential for use of transgenic mice in research. Because integration loci of transgenes are usually unknown due to their random insertion, assessment of transgene zygosity remains a challenge. Current zygosity genotyping methods (progeny testing, qPCR, and NGS-computational biology analysis) are time consuming, prone to error or technically challenging. Here, we developed a novel method to determine transgene zygosity requiring no knowledge of transgene insertion loci. This method applies allele-specific restriction enzyme digestion of PCR products (RE/PCR) to rapidly and reliably quantify transgene zygosity. We demonstrate the applicability of this method to three transgenic strains of mice ( Tg, , and ) harboring a unique restriction enzyme site on either the transgene or its homologous sequence in the mouse genome. This method is as accurate as the gold standard of progeny testing but requires 2 d instead of a month or more. It is also exceedingly more accurate than the most commonly used approach of qPCR quantification. Our novel method represents a significant technical advance in determining transgene zygosities in mice.
Topics: Mice; Animals; Genotype; Alleles; Transgenes; Mice, Transgenic; Base Sequence
PubMed: 37037594
DOI: 10.26508/lsa.202201729 -
Regulatory Toxicology and Pharmacology... Mar 2020Regulations governing the safety assessment of genetically engineered (GE) crops require studies that measure the expression levels of the transgene products (proteins...
Regulations governing the safety assessment of genetically engineered (GE) crops require studies that measure the expression levels of the transgene products (proteins and double-stranded RNA) in the GE crop; furthermore, the regulations also often mandate the inclusion of an entry of the GE crop that is sprayed with the herbicide to which tolerance was engineered and a non-sprayed entry of the GE crop in said studies. The hypothesized unique risk of altered transgene expression in response to application of herbicides related to herbicide-tolerant GE crops, compared with application of other herbicides, is not readily apparent. Field studies were conducted with GE maize, soybean, and cotton breeding stacks containing multiple herbicide tolerance traits; studies included plots that were sprayed with the trait-related herbicides and plots that were unsprayed. The GE herbicide-tolerance traits and complimentary herbicides investigated here comprise the majority of those that are currently in commercial use. Transgene product expression was characterized in crop tissues that were collected throughout the growing season. Results confirm the expectation, which is based on the fact that modes of action and regulatory elements in the genetic constructs of the herbicide-tolerance traits are well understood, that applying herbicides associated with GE herbicide-tolerance traits does not meaningfully affect transgene expression. These findings call into question the routine requirement for the inclusion of herbicide sprayed and non-sprayed entries in transgene-expression studies designed to support risk assessment.
Topics: Crops, Agricultural; Genetic Engineering; Herbicides; Plants, Genetically Modified; Transgenes; Zea mays
PubMed: 31884154
DOI: 10.1016/j.yrtph.2019.104572 -
International Journal of Molecular... Nov 2021It is vital to develop high-throughput methods to determine transgene copy numbers initially and zygosity during subsequent breeding. In this study, the target sequence...
It is vital to develop high-throughput methods to determine transgene copy numbers initially and zygosity during subsequent breeding. In this study, the target sequence of the previously reported endogenous reference gene was analyzed using 633 maize inbred lines, and two SNPs were observed. These SNPs significantly increased the PCR efficiency, while the newly developed gene assay (hmg-taq-F2/R2) excluding these SNPs reduced the efficiency into normal ranges. The TaqMan amplification efficiency of and with newly developed primers was calculated as 0.993 and 1.000, respectively. The inter-assay coefficient of variation (CV) values for the and genes varied from 1.18 to 2.94%. The copy numbers of the transgene using new TaqMan assays were identical to those using dPCR. Significantly, the precision of one repetition reached 96.7% of that of three repetitions of single-copy plants analyzed by simple random sampling, and the actual accuracy reached 95.8%, confirmed by T and T progeny. With the high-throughput DNA extraction and automated data analysis procedures developed in this study, nearly 2700 samples could be analyzed within eight hours by two persons. The combined results suggested that the new gene assay developed here could be a universal maize reference gene system, and the new assay has high throughput and high accuracy for large-scale screening of maize varieties around the world.
Topics: DNA Copy Number Variations; DNA Primers; Gene Dosage; Plant Breeding; Plants, Genetically Modified; Transgenes; Zea mays
PubMed: 34830369
DOI: 10.3390/ijms222212487 -
Nucleic Acids Research Oct 2023Artificial microRNAs (amiRNAs) are highly specific, 21-nucleotide (nt) small RNAs designed to silence target transcripts. In plants, their application as...
Artificial microRNAs (amiRNAs) are highly specific, 21-nucleotide (nt) small RNAs designed to silence target transcripts. In plants, their application as biotechnological tools for functional genomics or crop improvement is limited by the need of transgenically expressing long primary miRNA (pri-miRNA) precursors to produce the amiRNAs in vivo. Here, we analyzed the minimal structural and sequence requirements for producing effective amiRNAs from the widely used, 521-nt long AtMIR390a pri-miRNA from Arabidopsis thaliana. We functionally screened in Nicotiana benthamiana a large collection of constructs transiently expressing amiRNAs against endogenous genes and from artificially shortened MIR390-based precursors and concluded that highly effective and accurately processed amiRNAs can be produced from a chimeric precursor of only 89 nt. This minimal precursor was further validated in A. thaliana transgenic plants expressing amiRNAs against endogenous genes. Remarkably, minimal but not full-length precursors produce authentic amiRNAs and induce widespread gene silencing in N. benthamiana when expressed from an RNA virus, which can be applied into leaves by spraying infectious crude extracts. Our results reveal that the length of amiRNA precursors can be shortened without affecting silencing efficacy, and that viral vectors including minimal amiRNA precursors can be applied in a transgene-free manner to induce whole-plant gene silencing.
Topics: MicroRNAs; Gene Silencing; Plants, Genetically Modified; Nicotiana; Transgenes; Arabidopsis
PubMed: 37713607
DOI: 10.1093/nar/gkad747 -
Cancer Science May 2008Cancer gene therapy, in which pharmacologically active compounds are administered to cancer patients in a genetic form, has been examined not only in animals but also in... (Review)
Review
Cancer gene therapy, in which pharmacologically active compounds are administered to cancer patients in a genetic form, has been examined not only in animals but also in cancer patients. Viral vector-induced severe side effects in patients have greatly underscored the importance of non-viral gene transfer methods. Even though the importance of pharmacokinetics is undoubtedly understood in the development of anticancer therapies, its importance has been less well recognized in non-viral cancer gene therapy. When transgene products express their activity within transduced cells, such as herpes simplex virus type 1 thymidine kinase and short hairpin RNA, the pharmacokinetics of the vectors and the expression profiles of the transgenes will determine the efficacy of gene transfer. The percentage of cells transduced is highly important if few by-stander effects are expected. If transgene products are secreted from cells into the blood circulation, such as interferons and interleukins, the pharmacokinetics of transgenes becomes a matter of significant importance. Then, any approach to increasing the level and duration of transgene expression will increase the therapeutic effects of cancer gene therapy. Here we review the pharmacokinetics of both non-viral vectors and transgene products, and discuss what should be done to achieve safer and more effective non-viral cancer gene therapy.
Topics: Genetic Therapy; Genetic Vectors; Humans; Models, Biological; Neoplasms; Transgenes
PubMed: 18294288
DOI: 10.1111/j.1349-7006.2008.00774.x -
Advanced Drug Delivery Reviews Jul 2009Numerous preclinical studies have demonstrated the efficacy of viral gene delivery vectors, and recent clinical trials have shown promising results. However, the tight... (Review)
Review
Numerous preclinical studies have demonstrated the efficacy of viral gene delivery vectors, and recent clinical trials have shown promising results. However, the tight control of transgene expression is likely to be required for therapeutic applications and in some instances, for safety reasons. For this purpose, several ligand-dependent transcription regulatory systems have been developed. Among these, the tetracycline-regulatable system is by far the most frequently used and the most advanced towards gene therapy trials. This review will focus on this system and will describe the most recent progress in the regulation of transgene expression in various organs, including the muscle, the retina and the brain. Since the development of an immune response to the transactivator was observed following gene transfer in the muscle of nonhuman primate, focus will be therefore, given on the immune response to transgene products of the tetracycline inducible promoter.
Topics: Animals; Anti-Bacterial Agents; Gene Expression Regulation; Humans; Primates; Tetracycline; Transcriptional Activation; Transgenes
PubMed: 19394373
DOI: 10.1016/j.addr.2008.12.016