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1.
Equine Vet J ; 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39267222

RESUMEN

Gene doping, the use of gene therapy or genetic manipulation to enhance athletic performance, has emerged as a potential threat to the integrity and welfare of equine sports, such as horse racing and equestrian sports. This review aims to provide an overview of gene doping in horses, including the underlying technologies, potential applications, detection methods, ethical concerns and future perspectives. By understanding the current landscape of gene doping in horses, stakeholders can work together to develop strategies to safeguard the integrity of equine sports.

2.
Genes (Basel) ; 15(9)2024 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-39336823

RESUMEN

BACKGROUND/OBJECTIVES: Transgene applications, ranging from gene therapy to the development of stable cell lines and organisms, rely on maintaining the expression of transgenes. To date, the use of plasmid-based transgenes has been limited by the loss of their expression shortly after their delivery into the target cells. The short-lived expression of plasmid-based transgenes has been largely attributed to host-cell-mediated degradation and/or silencing of transgenes. The development of chromatin-based strategies for gene delivery has the potential to facilitate defining the requirements for establishing epigenetic states and to enhance transgene expression for numerous applications. METHODS: To assess the impact of "priming" plasmid-based transgenes to adopt accessible chromatin states to promote gene expression, nucleosome positioning elements were introduced at promoters of transgenes, and vectors were pre-assembled into nucleosomes containing unmodified histones or mutants mimicking constitutively acetylated states at residues 9 and 14 of histone H3 or residue 16 of histone H4 prior to their introduction into cells, then the transgene expression was monitored over time. RESULTS: DNA sequences capable of positioning nucleosomes could positively impact the expression of adjacent transgenes in a distance-dependent manner in the absence of their pre-assembly into chromatin. Intriguingly, the pre-assembly of plasmids into chromatin facilitated the prolonged expression of transgenes relative to plasmids that were not pre-packaged into chromatin. Interactions between pre-assembled chromatin states and nucleosome positioning-derived effects on expression were also assessed and, generally, nucleosome positioning played the predominant role in influencing gene expression relative to priming with hyperacetylated chromatin states. CONCLUSIONS: Strategies incorporating nucleosome positioning elements and the pre-assembly of plasmids into chromatin prior to nuclear delivery can modulate the expression of plasmid-based transgenes.


Asunto(s)
Ensamble y Desensamble de Cromatina , Histonas , Nucleosomas , Transgenes , Nucleosomas/genética , Nucleosomas/metabolismo , Histonas/genética , Histonas/metabolismo , Ensamble y Desensamble de Cromatina/genética , Humanos , Cromatina/genética , Cromatina/metabolismo , Plásmidos/genética , Regiones Promotoras Genéticas , Animales
3.
Mol Ther Oncol ; 32(3): 200833, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39184876

RESUMEN

Effective transgene expression is critical for genetically engineered cell therapy. Therefore, one of CAR-T cell therapy's critical areas of interest, both in registered products and next-generation approaches is the expression of transgenes. It turns out that various constitutive promoters used in clinical products may influence CAR-T cell antitumor effectiveness and impact the manufacturing process. Furthermore, next-generation CAR-T starts to install remotely controlled inducible promoters or even autonomous expression systems, opening new ways of priming, boosting, and increasing the safety of CAR-T. In this article, a wide range of constitutive and inducible promoters has been grouped and structured, making it possible to compare their pros and cons as well as clinical usage. Finally, logic gates based on Synthetic Notch have been elaborated, demonstrating the coupling of desired external signals with genetically engineered cellular responses.

4.
Drug Test Anal ; 2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-38992991

RESUMEN

Due to the ease of collection, transport and storage, the use of dried blood spots (DBS) offers an attractive alternative matrix for detection of the abuse of gene therapy, otherwise known as gene doping. This study evaluated the recovery, extraction efficiency and resulting detection capability of DNA from DBS by evaluating different target types, DNA extraction kits, the number of punches and blood tube preservatives. The long-term storage stability of low-copy-number transgene targets in DBS was not assessed in this study but would be noteworthy to investigate further. DNA was quantified using two detection methods: qPCR and digital PCR (dPCR). Using six punches with the Qiagen Investigator kit gave the best overall DNA yield compared with other extraction methods. Including three punches, however, gave better DNA extraction efficiency. Reference material could be detected using qPCR and dPCR in DBS spiked with 5000 copies/mL of blood (approximately 15 copies per 3 mm of punch). The optimal DNA extraction protocol was used on DBS samples from a custom recombinant adeno-associated virus administration study and showed successful detection of vector targets in DBS samples.

5.
New Phytol ; 243(2): 526-536, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38803120

RESUMEN

Forests make immense contributions to societies in the form of ecological services and sustainable industrial products. However, they face major challenges to their viability and economic use due to climate change and growing biotic and economic threats, for which recombinant DNA (rDNA) technology can sometimes provide solutions. But the application of rDNA technologies to forest trees faces major social and biological obstacles that make its societal acceptance a 'wicked' problem without straightforward solutions. We discuss the nature of these problems, and the social and biological innovations that we consider essential for progress. As case studies of biological challenges, we focus on studies of modifications in wood chemistry and transformation efficiency. We call for major innovations in regulations, and the dissolution of method-based market barriers, that together could lead to greater research investments, enable wide use of field studies, and facilitate the integration of rDNA-modified trees into conventional breeding programs. Without near-term adoption of such innovations, rDNA-based solutions will be largely unavailable to help forests adapt to the growing stresses from climate change and the proliferation of forest pests, nor will they be available to provide economic and environmental benefits from expanded use of wood and related bioproducts as part of an expanding bioeconomy.


Asunto(s)
Biotecnología , Bosques , Biotecnología/métodos , Madera , Árboles , Cambio Climático
6.
Clin Genet ; 105(4): 364-375, 2024 04.
Artículo en Inglés | MEDLINE | ID: mdl-38129135

RESUMEN

Biallelic loss-of-function mutation of NUP210L, encoding a testis-specific nucleoporin, has been reported in an infertile man whose spermatozoa show uncondensed heads and histone retention. Mice with a homozygous transgene intronic insertion in Nup210l were infertile but spermatozoa had condensed heads. Expression from this insertion allele is undefined, however, and residual NUP210L production could underlie the milder phenotype. To resolve this issue, we have created Nup210lem1Mjmm , a null allele of Nup210l, in the mouse. Nup210lem1Mjmm homozygotes show uniform mild anomalies of sperm head morphology and decreased motility, but nuclear compaction and histone removal appear unaffected. Thus, our mouse model does not support that NUP210L loss alone blocks spermatid nuclear compaction. Re-analyzing the patient's exome data, we identified a rare, potentially pathogenic, heterozygous variant in nucleoporin gene NUP153 (p.Pro485Leu), and showed that, in mouse and human, NUP210L and NUP153 colocalize at the caudal nuclear pole in elongating spermatids and spermatozoa. Unexpectedly, in round spermatids, NUP210L and NUP153 localisation differs between mouse (nucleoplasm) and human (nuclear periphery). Our data suggest two explanations for the increased phenotypic severity associated with NUP210L loss in human compared to mouse: a genetic variant in human NUP153 (p.Pro485Leu), and inter-species divergence in nuclear pore function in round spermatids.


Asunto(s)
Histonas , Infertilidad Masculina , Masculino , Ratones , Humanos , Animales , Histonas/genética , Histonas/metabolismo , Proteínas de Complejo Poro Nuclear/genética , Proteínas de Complejo Poro Nuclear/metabolismo , Espermatogénesis/genética , Semen/metabolismo , Espermatozoides/metabolismo , Testículo/metabolismo , Infertilidad Masculina/genética
7.
Cancers (Basel) ; 15(17)2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37686488

RESUMEN

Prostate cancer is a common cancer among men and typically progresses slowly for several decades before becoming aggressive and spreading to other organs, leaving few treatment options. While large animals have been studied, the dog's prostate is anatomically similar to humans and has been used to study spontaneous prostate cancer. However, most research currently focuses on the mouse as a model organism due to the ability to genetically modify their prostatic tissues for molecular analysis. One milestone in this research was the identification of the prostate-specific promoter Probasin, which allowed for the prostate-specific expression of transgenes. This has led to the generation of mice with aggressive prostatic tumors through overexpression of the SV40 oncogene. The Probasin promoter is also used to drive Cre expression and has allowed researchers to generate prostate-specific loss-of-function studies. Another landmark moment in the process of modeling prostate cancer in mice was the orthoptic delivery of viral particles. This technology allows the selective overexpression of oncogenes from lentivirus or the use of CRISPR to generate complex loss-of-function studies. These genetically modified models are complemented by classical xenografts of human prostate tumor cells in immune-deficient mice. Overall, pre-clinical models have provided a portfolio of model systems to study and address complex mechanisms in prostate cancer for improved treatment options. This review will focus on the advances in each technique.

8.
Drug Test Anal ; 2023 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-37671588

RESUMEN

Gene doping in horses is a threat to the fairness in sport and has serious implications for animal welfare. To investigate the effect of long-term storage on the detection of AAV in plasma and whole blood, samples from an administration study using an adeno-associated virus serotype 6 expressing green fluorescence protein (AAV6-GFP) were stored at -20°C for 8 months before analysis. The AAV vector was detected in stored plasma samples, following the same detection profile as the fresh plasma samples. The stored blood showed lower overall DNA detection but followed the same detection profile as the plasma samples. This study provides confidence that re-analysing plasma samples and/or analysing a frozen 'B' sample with different matrix such as whole blood after prolonged storage will still result in the detection of gene doping material.

9.
Wei Sheng Yan Jiu ; 52(4): 561-578, 2023 Jul.
Artículo en Chino | MEDLINE | ID: mdl-37679068

RESUMEN

OBJECTIVE: To evaluate the protein efficiency ratio(PER) of genetically modified pork powder with fat-1 gene(GM group), and thus evaluate whether the nutritional evaluation value of fat-1 gene pork powder has changed. METHODS: Sixty weaned SD rats(60-80 g) were randomly divided into casein group, parental control group and GM group according to sex and weight, 20 rats in each group, half of each sex. The rats in the three groups were fed with corresponding formulated feed containing 10% protein for 28 days. The body weight and food intake of each group were recorded weekly. Blood was collected at the end of the experiment to determine hematology and blood biochemical indexes. The food utilization rate, organ/body weigh indexes, PER and corrected PER were calculated. RESULTS: The weight of rats in all groups increased steadily during the experimental period. Statistically significant differences were found in some hematology and blood biochemical indexes and organ/body weigh indexes. No biologically significant changes were found. The food utilization rate of GM group was higher than that of casein group(P<0.05), which was equivalent to that in the parental control group. The PER of both genetically modified pork powder with fat-1 gene and parental white pork powder were higher than that of casein(P<0.05). CONCLUSION: The PER of genetically modified pork powder with fat-1 gene was equal to that of its parental white pork powder.


Asunto(s)
Carne de Cerdo , Carne Roja , Porcinos , Animales , Ratas , Ratas Sprague-Dawley , Caseínas , Polvos
11.
Plants (Basel) ; 12(13)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37447074

RESUMEN

Mexico harbors over 50% of maize's genetic diversity in the Americas. Native maize varieties are actively managed by small-scale producers within a diverse array of cultivation systems. Seed lot use, exchange and admixture has consequences for the in situ conservation of such varieties. Here we analyze native maize seed management dynamics from 906 small-scale producers surveyed in three Mexican states: Mexico City, Oaxaca and Chiapas. Furthermore, we analyze how their management practices can relate to transgene presence, which was experimentally documented for maize samples associated with the applied surveys. Through a data mining approach, we investigated which practices might be related with a higher probability of transgene presence. The variables found to have a strong spatial association with transgene presence were: for Mexico City, maize producers with larger parcels; for Oaxaca, producer's age (43-46 years) and the sale of seed; for Chiapas, the use of agricultural machinery and younger producers (37-43 years). Additionally, transgene presence and frequency within the socioeconomic regions of Oaxaca and Chiapas was analyzed. In Oaxaca, higher transgene frequencies occurred in regions where transgene presence had been previously reported. In Chiapas, the border regions with Guatemala as well as a region where reproduction of improved seed takes place, the highest proportion of positive samples were found. A detailed mapping of regional seed markets and seed exchange sites together with deployment of national and local biosecurity measures, could help prevent the further spread of transgenes into native maize varieties, as well as improve conservation efforts.

12.
Transgenic Res ; 32(5): 399-409, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37326744

RESUMEN

The presence and levels of transgenic maize in Mexico and the effect this could have on local landraces or closely related species such as teosinte has been the subject of several previous reports, some showing contrasting results. Cultural, social and political factors all affect maize cultivation in Mexico and although since 1998 there has been a moratorium on the commercial cultivation of transgenic maize, Mexico imports maize, mainly from the USA where transgenic cultivars are widely grown. Additionally extensive migration between rural areas in Mexico and the USA and customs of seed exchange between farmers may also play an unintentional role in the establishment of transgenic seed. A comprehensive study of all Mexican maize landraces throughout the country is not feasible, however this report presents data based on analysis of 3204 maize accessions obtained from the central region of Mexico (where permits have never been authorized for cultivation of transgenic maize) and the northern region (where for a short period authorization for experimental plots was granted). The results of the study confirm that transgenes are present in all the geographical areas sampled and were more common in germplasm obtained in the northern region. However, there was no evidence that regions where field trials had been authorized showed higher levels of transgene presence or that the morphology of seed lots harboring transgenic material was significantly modified in favor of expected transgenic phenotypes.


Asunto(s)
Zea mays , Animales , Plantas Modificadas Genéticamente/genética , Zea mays/genética , México , Transgenes , Animales Modificados Genéticamente
13.
Drug Test Anal ; 15(8): 879-888, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37056164

RESUMEN

Illicit administration of transgene into horses is a form of gene doping that has been a key concern in equine sports. The large number of potential performance-enhancing transgenes has demanded a cost-effective and reliable detection method. Multiplex qPCR is a relevant technique, but the cross-talking between fluorophores and high background noise limits the method sensitivity and specificity. This study reports a simpler multiplexing approach by using the same fluorophore for four hydrolysis probes each targeting one of the four transgenes: human growth hormone, insulin-like growth factor 1, equine erythropoietin and interleukin-10. Any positive findings from this multiplex qPCR assay can then be confirmed by individual qPCR assays to identify potential transgene(s). This has effectively eliminated the cross-talking issue and allowed an improved signal-to-noise than conventional multiplex qPCR assay. It has also removed the limitation imposed by the available choice of fluorophores and optical channels of qPCR instruments on the number of transgenes that can be analysed in a multiplex qPCR assay. This novel multiplex qPCR has been successfully validated. The estimated limits of detection were ~1500-2500 copies/mL of blood, thus demonstrating comparable sensitivity with the corresponding duplex qPCR assays. Concurring results were obtained by analysing hundreds of official blood samples provided by racehorses with this multiplex qPCR assay and the accredited individual duplex qPCR assays. This novel multiplex qPCR assay for detecting multiple transgenes is a cost-effective screening method using a conventional laboratory setup and has opened up the potential to include the testing of additional transgenes in a single assay.


Asunto(s)
Doping en los Deportes , Eritropoyetina , Humanos , Animales , Caballos/genética , Doping en los Deportes/prevención & control , Transgenes , Eritropoyetina/genética , Sensibilidad y Especificidad , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos
14.
Circ Res ; 132(11): e171-e187, 2023 05 26.
Artículo en Inglés | MEDLINE | ID: mdl-37057625

RESUMEN

BACKGROUND: Cardiac contractile function requires high energy from mitochondria, and Ca2+ from the sarcoplasmic reticulum (SR). Via local Ca2+ transfer at close mitochondria-SR contacts, cardiac excitation feedforward regulates mitochondrial ATP production to match surges in demand (excitation-bioenergetics coupling). However, pathological stresses may cause mitochondrial Ca2+ overload, excessive reactive oxygen species production and permeability transition, risking homeostatic collapse and myocyte loss. Excitation-bioenergetics coupling involves mitochondria-SR tethers but the role of tethering in cardiac physiology/pathology is debated. Endogenous tether proteins are multifunctional; therefore, nonselective targets to scrutinize interorganelle linkage. Here, we assessed the physiological/pathological relevance of selective chronic enhancement of cardiac mitochondria-SR tethering. METHODS: We introduced to mice a cardiac muscle-specific engineered tether (linker) transgene with a fluorescent protein core and deployed 2D/3D electron microscopy, biochemical approaches, fluorescence imaging, in vivo and ex vivo cardiac performance monitoring and stress challenges to characterize the linker phenotype. RESULTS: Expressed in the mature cardiomyocytes, the linker expanded and tightened individual mitochondria-junctional SR contacts; but also evoked a marked remodeling with large dense mitochondrial clusters that excluded dyads. Yet, excitation-bioenergetics coupling remained well-preserved, likely due to more longitudinal mitochondria-dyad contacts and nanotunnelling between mitochondria exposed to junctional SR and those sealed away from junctional SR. Remarkably, the linker decreased female vulnerability to acute massive ß-adrenergic stress. It also reduced myocyte death and mitochondrial calcium-overload-associated myocardial impairment in ex vivo ischemia/reperfusion injury. CONCLUSIONS: We propose that mitochondria-SR/endoplasmic reticulum contacts operate at a structural optimum. Although acute changes in tethering may cause dysfunction, upon chronic enhancement of contacts from early life, adaptive remodeling of the organelles shifts the system to a new, stable structural optimum. This remodeling balances the individually enhanced mitochondrion-junctional SR crosstalk and excitation-bioenergetics coupling, by increasing the connected mitochondrial pool and, presumably, Ca2+/reactive oxygen species capacity, which then improves the resilience to stresses associated with dysregulated hyperactive Ca2+ signaling.


Asunto(s)
Señalización del Calcio , Retículo Sarcoplasmático , Femenino , Ratones , Animales , Retículo Sarcoplasmático/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Miocardio/metabolismo , Miocitos Cardíacos/metabolismo , Mitocondrias Cardíacas/metabolismo , Calcio/metabolismo
15.
Front Genet ; 14: 1121462, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36968584

RESUMEN

Climate change is significantly impacting agricultural production worldwide. Peanuts provide food and nutritional security to millions of people across the globe because of its high nutritive values. Drought and heat stress alone or in combination cause substantial yield losses to peanut production. The stress, in addition, adversely impact nutritional quality. Peanuts exposed to drought stress at reproductive stage are prone to aflatoxin contamination, which imposes a restriction on use of peanuts as health food and also adversely impact peanut trade. A comprehensive understanding of the impact of drought and heat stress at physiological and molecular levels may accelerate the development of stress tolerant productive peanut cultivars adapted to a given production system. Significant progress has been achieved towards the characterization of germplasm for drought and heat stress tolerance, unlocking the physiological and molecular basis of stress tolerance, identifying significant marker-trait associations as well major QTLs and candidate genes associated with drought tolerance, which after validation may be deployed to initiate marker-assisted breeding for abiotic stress adaptation in peanut. The proof of concept about the use of transgenic technology to add value to peanuts has been demonstrated. Advances in phenomics and artificial intelligence to accelerate the timely and cost-effective collection of phenotyping data in large germplasm/breeding populations have also been discussed. Greater focus is needed to accelerate research on heat stress tolerance in peanut. A suits of technological innovations are now available in the breeders toolbox to enhance productivity and nutritional quality of peanuts in harsh environments. A holistic breeding approach that considers drought and heat-tolerant traits to simultaneously address both stresses could be a successful strategy to produce climate-resilient peanut genotypes with improved nutritional quality.

16.
C R Biol ; 345(4): 149-174, 2023 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-36847123

RESUMEN

Plant varieties exhibiting unstable or variegated phenotypes, or showing virus recovery have long remained a mystery. It is only with the development of transgenic plants 40 years ago that the epigenetic features underlying these phenomena were elucidated. Indeed, the study of transgenic plants that did not express the introduced sequences revealed that transgene loci sometimes undergo transcriptional gene silencing (TGS) or post-transcriptional gene silencing (PTGS) by activating epigenetic defenses that naturally control transposable elements, duplicated genes or viruses. Even when they do not trigger TGS or PTGS spontaneously, stably expressed transgenes driven by viral promoters set apart from endogenous genes in their epigenetic regulation. As a result, transgenes driven by viral promoters are capable of undergoing systemic PTGS throughout the plant, whereas endogenous genes can only undergo local PTGS in cells where RNA quality control is impaired. Together, these results indicate that the host genome distinguishes self from non-self at the epigenetic level, allowing PTGS to eliminate non-self, and preventing PTGS to become systemic and kill the plant when it is locally activated against deregulated self.


Les phénotypes instables ou mosaïques de certaines variétés de plantes, et la capacité de certaines plantes à récupérer après une infection virale sont longtemps demeurés des mystères. Ce n'est qu'avec le développement des plantes transgéniques il y a 40 ans que les caractéristiques épigénétiques de ces phénomènes ont été élucidées. En effet, l'étude de plantes transgéniques qui n'exprimaient pas les séquences introduites a révélé que les transgènes pouvaient parfois subir une extinction transcriptionnelle (TGS) ou post-transcriptionnelle (PTGS) en activant des défenses épigénétiques endogènes naturellement dirigées contre les éléments transposables, les gènes dupliqués ou les virus. Même lorsqu'ils ne subissent pas le TGS ou le PTGS spontanément, les transgènes exprimés de façon stable sous le contrôle de promoteurs viraux se distinguent des gènes endogènes par leurs caractéristiques épigénétiques. Il en résulte que les transgènes exprimés sous le contrôle de promoteurs viraux sont capables de subir un PTGS systémique dans l'ensemble de la plante, alors que les gènes endogènes ne peuvent subir qu'un PTGS restreint aux cellules où le contrôle de qualité des ARN (RQC) est défectueux. L'ensemble de ces données indique que le génome des plantes distingue le soi du non-soi au niveau épigénétique, permettant d'une part au PTGS d'éliminer le non-soi, et d'autre part d'empêcher le PTGS de devenir systémique et de tuer la plante quand il est activé localement pour éliminer le soi défectueux.


Asunto(s)
Epigénesis Genética , Silenciador del Gen , Plantas Modificadas Genéticamente/genética , Transgenes , Regulación de la Expresión Génica de las Plantas
17.
Curr Drug Deliv ; 20(4): 350-370, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35593362

RESUMEN

Cancer immunotherapy has advanced significantly in recent years. Nanocarriers like liposomes can improve cancer immunotherapy and even stronger immune responses by improving cell type-specific distribution. Liposomes are lipid bilayer vesicles that are biodegradable and biocompatible and are often used as smart delivery systems for both hydrophobic and hydrophilic bioactive. Whereas the idea of employing liposomes for administering drugs has been known since the 1960s, the early 2000s saw continuing technological advances and formulations for drug entrapment and manufacturing. Modern deterministic studies have tried discovering more about how genetic material is delivered through liposomes. Liposomes' interactions with cells are still a bit of mystery. Liposome-mediated transmission of genetic material experiences systemic impediments perlysosomal degradation, endosomal escape, and nuclear uptake. Controlling the physical architecture and chemical properties of liposome structures, such as lipid-to-DNA charge, ester bond composition, size, and ligand complexation structure, is critical for targeting liposomes' success as vehicles for gene delivery. This analysis focuses on advancements in ligand-targeted liposomes and theranostic (diagnostic) liposomes for cancer diagnosis and treatment. This review will explore the numerous transgene mechanisms and molecular targets implicated in cancer cell death and the associated benefits of using liposomal formulations throughout the years. This sequence of breakthroughs will interest aspiring researchers and the pharmaceutical industry involved in liposome development.


Asunto(s)
Liposomas , Neoplasias , Humanos , Liposomas/química , Ligandos , Neoplasias/tratamiento farmacológico , Composición de Medicamentos , Terapia Genética , Sistemas de Liberación de Medicamentos
18.
Plants (Basel) ; 11(23)2022 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-36501227

RESUMEN

The commercialization of transgenic herbicide-resistant (HR) crops may cause gene flow risk. If a transgene in progenies of transgenic crops and wild relatives is silencing, these progenies should be killed by the target herbicide, thus, the gene flow risk could be decreased. We obtained the progenies of backcross generations between wild Brassca juncea (AABB, 2n = 36) and glufosinate-resistant transgenic Brassica napus (AACC, 2n = 38, PAT gene located on the C-chromosome). They carried the HR gene but did not express it normally, i.e., gene silencing occurred. Meanwhile, six to nine methylation sites were found on the promoter of PAT in transgene-silencing progenies, while no methylation sites occurred on that in transgene-expressing progenies. In addition, transgene expressing and silencing backcross progenies showed similar fitness with wild Brassica juncea. In conclusion, we elaborate on the occurrence of transgene-silencing event in backcross progenies between transgenic crop utilizing alien chromosomes and their wild relatives, and the DNA methylation of the transgene promoter was an important factor leading to gene silencing. The insertion site of the transgene could be considered a strategy to reduce the ecological risk of transgenic crops, and applied to cultivate lower gene flow HR crops in the future.

19.
Acta Naturae ; 14(3): 46-56, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36348722

RESUMEN

Accurate measurement of tumor size and margins is crucial for successful oncotherapy. In the last decade, non-invasive imaging modalities, including optical imaging using non-radioactive substrates, deep-tissue imaging with radioactive substrates, and magnetic resonance imaging have been developed. Reporter genes play the most important role among visualization tools; their expression in tumors and metastases makes it possible to track changes in the tumor growth and gauge therapy effectiveness. Oncolytic viruses are often chosen as a vector for delivering reporter genes into tumor cells, since oncolytic viruses are tumor-specific, meaning that they infect and lyse tumor cells without damaging normal cells. The choice of reporter transgenes for genetic modification of oncolytic viruses depends on the study objectives and imaging methods used. Optical imaging techniques are suitable for in vitro studies and small animal models, while deep-tissue imaging techniques are used to evaluate virotherapy in large animals and humans. For optical imaging, transgenes of fluorescent proteins, luciferases, and tyrosinases are used; for deep-tissue imaging, the most promising transgene is the sodium/iodide symporter (NIS), which ensures an accumulation of radioactive isotopes in virus-infected tumor cells. Currently, NIS is the only reporter transgene that has been shown to be effective in monitoring tumor virotherapy not only in preclinical but also in clinical studies.

20.
Cell Rep Methods ; 2(11): 100317, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36447645

RESUMEN

Naive human induced pluripotent stem cells (iPSCs) can be generated by reprogramming somatic cells with Sendai virus (SeV) vectors. However, only dermal fibroblasts have been successfully reprogrammed this way, and the process requires culture on feeder cells. Moreover, SeV vectors are highly persistent and inhibit subsequent differentiation of iPSCs. Here, we report a modified SeV vector system to generate transgene-free naive human iPSCs with superior differentiation potential. The modified method can be applied not only to fibroblasts but also to other somatic cell types. SeV vectors disappear quickly at early passages, and this approach enables the generation of naive iPSCs in a feeder-free culture. The naive iPSCs generated by this method show better differentiation to trilineage and extra-embryonic trophectoderm than those derived by conventional methods. This method can expand the application of iPSCs to research on early human development and regenerative medicine.


Asunto(s)
Células Madre Pluripotentes Inducidas , Humanos , Reprogramación Celular/genética , Virus Sendai/genética , Vectores Genéticos , Diferenciación Celular/genética
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