Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 121
Filter
1.
Nanotechnology ; 2024 Jun 21.
Article in English | MEDLINE | ID: mdl-38906117

ABSTRACT

The electromagnetic field enhancement mechanisms leading to surface-enhanced Raman scattering (SERS) of R6G molecules near Ti3C2Tx MXene flakes of different shapes and sizes are analyzed theoretically. In COMSOL simulations for the enhancement factor (EF) of SERS, the dye molecule is modeled as a small sphere with polarizability spectrum based on experimental data. It is demonstrated for the first time, that in the wavelength range 500 nm - 1000 nm the enhancement of Raman signal is largely conditioned by quadrupole surface plasmon (QSP) oscillations that induce strong polarization of MXene substrate. We show that in vis-NIR spectral range quadrupole SP resonances, strengthened due to interband transitions (IBT) provide EF values of the order of 105- 107in agreement with experimental data. The weak sensitivity of the EF to the shape and size of MXene nanoparticles (NPs) is interpreted as a consequence of the low dependence of the absorption cross-section of QSP oscillations and IBT on the geometry of the flakes. This reveals a new feature - the independence of EF on the geometry of MXene substrates, allowing to avoid the monitoring of the shape and size of flakes during their synthe- sis. Thus, MXene flakes can be advantageous for easy manufacturing of universal substrates for SERS applications. The electromagnetic SERS enhancement is determined by the "lightning rod" and "hot-spot" effects due to partial overlapping of absorption spectrum of the R6G molecule with these MXene resonances.

2.
Cureus ; 16(2): e54511, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38516492

ABSTRACT

Pilomatrixoma, also called epithelioma of Malherbe, is a benign neoplasm derived from hair follicle matrix cells. It usually presents as a solitary mass in the head and neck region and is more frequent in children and young adults, females, and the Caucasian population. Lesions equal to or greater than 5 cm are categorized as giant pilomatrixomas. We present a case of a 75-year-old female, with no known medical history, who was brought to the emergency department (ED) after falling on the street. She had a giant soft head tissue tumor, severe anemia due to intralesional chronic small hemorrhages and folates and cobalamin deficiencies, and delirant speech. The anatomopathological result of the biopsy of the tumor revealed to be a pilomatrixoma. The patient was then referred to plastic surgery, with complete excision of the tumor. After surgery, she was transferred to the psychiatric team, who assumed the delirant speech to be in the context of schizophrenia. She was discharged four months after admission.

3.
Nucleic Acids Res ; 52(5): 2740-2757, 2024 Mar 21.
Article in English | MEDLINE | ID: mdl-38321963

ABSTRACT

Prime editors have high potential for disease modelling and regenerative medicine efforts including those directed at the muscle-wasting disorder Duchenne muscular dystrophy (DMD). However, the large size and multicomponent nature of prime editing systems pose substantial production and delivery issues. Here, we report that packaging optimized full-length prime editing constructs in adenovector particles (AdVPs) permits installing precise DMD edits in human myogenic cells, namely, myoblasts and mesenchymal stem cells (up to 80% and 64%, respectively). AdVP transductions identified optimized prime-editing reagents capable of correcting DMD reading frames of ∼14% of patient genotypes and restoring dystrophin synthesis and dystrophin-ß-dystroglycan linkages in unselected DMD muscle cell populations. AdVPs were equally suitable for correcting DMD iPSC-derived cardiomyocytes and delivering dual prime editors tailored for DMD repair through targeted exon 51 deletion. Moreover, by exploiting the cell cycle-independent AdVP transduction process, we report that 2- and 3-component prime-editing modalities are both most active in cycling than in post-mitotic cells. Finally, we establish that combining AdVP transduction with seamless prime editing allows for stacking chromosomal edits through successive delivery rounds. In conclusion, AdVPs permit versatile investigation of advanced prime editing systems independently of their size and component numbers, which should facilitate their screening and application.


Subject(s)
Dystrophin , Genetic Therapy , Muscular Dystrophy, Duchenne , Humans , CRISPR-Cas Systems/genetics , Dystrophin/genetics , Dystrophin/metabolism , Gene Editing , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/therapy , Myoblasts/metabolism , Myocytes, Cardiac/metabolism
4.
Mol Ther Nucleic Acids ; 34: 102066, 2023 Dec 12.
Article in English | MEDLINE | ID: mdl-38034032

ABSTRACT

The European Cooperation in Science and Technology (COST) is an intergovernmental organization dedicated to funding and coordinating scientific and technological research in Europe, fostering collaboration among researchers and institutions across countries. Recently, COST Action funded the "Genome Editing to treat Human Diseases" (GenE-HumDi) network, uniting various stakeholders such as pharmaceutical companies, academic institutions, regulatory agencies, biotech firms, and patient advocacy groups. GenE-HumDi's primary objective is to expedite the application of genome editing for therapeutic purposes in treating human diseases. To achieve this goal, GenE-HumDi is organized in several working groups, each focusing on specific aspects. These groups aim to enhance genome editing technologies, assess delivery systems, address safety concerns, promote clinical translation, and develop regulatory guidelines. The network seeks to establish standard procedures and guidelines for these areas to standardize scientific practices and facilitate knowledge sharing. Furthermore, GenE-HumDi aims to communicate its findings to the public in accessible yet rigorous language, emphasizing genome editing's potential to revolutionize the treatment of many human diseases. The inaugural GenE-HumDi meeting, held in Granada, Spain, in March 2023, featured presentations from experts in the field, discussing recent breakthroughs in delivery methods, safety measures, clinical translation, and regulatory aspects related to gene editing.

5.
Cell Rep Methods ; 3(6): 100488, 2023 06 26.
Article in English | MEDLINE | ID: mdl-37426764

ABSTRACT

Current methods to generate human primordial germ cell-like cells (hPGCLCs) from human pluripotent stem cells (hPSCs) can be inefficient, and it is challenging to generate sufficient hPGCLCs to optimize in vitro gametogenesis. We present a differentiation method that uses diluted basement membrane extract (BMEx) and low BMP4 concentration to efficiently induce hPGCLC differentiation in scalable 2D cell culture. We show that BMEx overlay potentiated BMP/SMAD signaling, induced lumenogenesis, and increased expression of key hPGCLC-progenitor markers such as TFAP2A and EOMES. hPGCLCs that were generated using the BMEx overlay method were able to upregulate more mature germ cell markers, such as DAZL and DDX4, in human fetal ovary reconstitution culture. These findings highlight the importance of BMEx during hPGCLC differentiation and demonstrate the potential of the BMEx overlay method to interrogate the formation of PGCs and amnion in humans, as well as to investigate the next steps to achieve in vitro gametogenesis.


Subject(s)
Induced Pluripotent Stem Cells , Pluripotent Stem Cells , Female , Humans , Cell Differentiation , Germ Cells , Ovary
7.
Nucleic Acids Res ; 51(7): 3465-3484, 2023 04 24.
Article in English | MEDLINE | ID: mdl-36928106

ABSTRACT

Homology-directed recombination (HDR) between donor constructs and acceptor genomic sequences cleaved by programmable nucleases, permits installing large genomic edits in mammalian cells in a precise fashion. Yet, next to precise gene knock-ins, programmable nucleases yield unintended genomic modifications resulting from non-homologous end-joining processes. Alternatively, in trans paired nicking (ITPN) involving tandem single-strand DNA breaks at target loci and exogenous donor constructs by CRISPR-Cas9 nickases, fosters seamless and scarless genome editing. In the present study, we identified high-specificity CRISPR-Cas9 nucleases capable of outperforming parental CRISPR-Cas9 nucleases in directing genome editing through homologous recombination (HR) and homology-mediated end joining (HMEJ) with donor constructs having regular and 'double-cut' designs, respectively. Additionally, we explored the ITPN principle by demonstrating its compatibility with orthogonal and high-specificity CRISPR-Cas9 nickases and, importantly, report that in human induced pluripotent stem cells (iPSCs), in contrast to high-specificity CRISPR-Cas9 nucleases, neither regular nor high-specificity CRISPR-Cas9 nickases activate P53 signaling, a DNA damage-sensing response linked to the emergence of gene-edited cells with tumor-associated mutations. Finally, experiments in human iPSCs revealed that differently from HR and HMEJ genome editing based on high-specificity CRISPR-Cas9 nucleases, ITPN involving high-specificity CRISPR-Cas9 nickases permits editing allelic sequences associated with essentiality and recurrence in the genome.


Subject(s)
CRISPR-Cas Systems , Gene Editing , Animals , Humans , CRISPR-Cas Systems/genetics , DNA Breaks, Double-Stranded , Gene Editing/methods , Genomics , Induced Pluripotent Stem Cells , Mammals
8.
Mol Ther Nucleic Acids ; 31: 746-762, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36937620

ABSTRACT

Genome editing based on dual CRISPR-Cas9 complexes (multiplexes) permits removing specific genomic sequences in living cells leveraging research on functional genomics and genetic therapies. Delivering the required large and multicomponent reagents in a synchronous and stoichiometric manner remains, however, challenging. Moreover, uncoordinated activity of independently acting CRISPR-Cas9 multiplexes increases the complexity of genome editing outcomes. Here, we investigate the potential of fostering precise multiplexing genome editing using high-capacity adenovector particles (AdVPs) for the delivery of Cas9 ortholog fusion constructs alone (forced Cas9 heterodimers) or together with their cognate guide RNAs (forced CRISPR-Cas9 heterodimers). We demonstrate that the efficiency and accuracy of targeted chromosomal DNA deletions achieved by single AdVPs encoding forced CRISPR-Cas9 heterodimers is superior to that obtained when the various components are delivered separately. Finally, all-in-one AdVP delivery of forced CRISPR-Cas9 heterodimers triggers robust DMD exon 51 splice site excision resulting in reading frame restoration and selection-free detection of dystrophin in muscle cells derived from Duchenne muscular dystrophy patients. In conclusion, AdVPs promote precise multiplexing genome editing through the integrated delivery of forced CRISPR-Cas9 heterodimer components, which, in comparison with split conventional CRISPR-Cas9 multiplexes, engage target sequences in a more coordinated fashion.

9.
Nucleic Acids Res ; 50(13): 7761-7782, 2022 07 22.
Article in English | MEDLINE | ID: mdl-35776127

ABSTRACT

Targeted chromosomal insertion of large genetic payloads in human cells leverages and broadens synthetic biology and genetic therapy efforts. Yet, obtaining large-scale gene knock-ins remains particularly challenging especially in hard-to-transfect stem and progenitor cells. Here, fully viral gene-deleted adenovector particles (AdVPs) are investigated as sources of optimized high-specificity CRISPR-Cas9 nucleases and donor DNA constructs tailored for targeted insertion of full-length dystrophin expression units (up to 14.8-kb) through homologous recombination (HR) or homology-mediated end joining (HMEJ). In muscle progenitor cells, donors prone to HMEJ yielded higher CRISPR-Cas9-dependent genome editing frequencies than HR donors, with values ranging between 6% and 34%. In contrast, AdVP transduction of HR and HMEJ substrates in induced pluripotent stem cells (iPSCs) resulted in similar CRISPR-Cas9-dependent genome editing levels. Notably, when compared to regular iPSCs, in p53 knockdown iPSCs, CRISPR-Cas9-dependent genome editing frequencies increased up to 6.7-fold specifically when transducing HMEJ donor constructs. Finally, single DNA molecule analysis by molecular combing confirmed that AdVP-based genome editing achieves long-term complementation of DMD-causing mutations through the site-specific insertion of full-length dystrophin expression units. In conclusion, AdVPs are a robust and flexible platform for installing large genomic edits in human cells and p53 inhibition fosters HMEJ-based genome editing in iPSCs.


Subject(s)
Dystrophin , Gene Editing , Muscular Dystrophy, Duchenne/genetics , Muscular Dystrophy, Duchenne/therapy , CRISPR-Cas Systems/genetics , Dystrophin/genetics , Dystrophin/metabolism , Endonucleases/genetics , Endonucleases/metabolism , Gene Editing/methods , Humans , Muscle Cells/metabolism , Muscular Dystrophy, Duchenne/pathology , Tumor Suppressor Protein p53/metabolism
10.
Micron ; 160: 103303, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35709545

ABSTRACT

In mono- and few-layer 2D materials, the exact number of layers is a critical parameter, determining the materials' properties and thus their performance in future nano-devices. Here, we evaluate in a systematic manner the signature of exfoliated free-standing mono- and few-layer MoS2 and MoTe2 in TEM experiments such as high-resolution transmission electron microscopy, electron energy-loss spectroscopy, and 3D electron diffraction. A reference for the number of layers has been determined by optical contrast and AFM measurements on a substrate. Comparing the results, we discuss strengths and limitations, benchmarking the three TEM methods with respect to their ability to identify the exact number of layers.

11.
Br J Neurosurg ; : 1-4, 2021 Nov 02.
Article in English | MEDLINE | ID: mdl-34726561

ABSTRACT

Cranioplasty with titanium mesh provides a stable and cosmetically sound option for the correction of extensive skull bone defects following trauma or tumour surgery with osseous involvement. Meningiomas are for the most part benign lesions that are amenable to surgical cure, however lesions with extradural extension pose additional challenges not only due to increased technical difficulty in achieving gross total resection but also because of distinct biological behaviour. We describe the case of a 43-years-old woman that had been submitted to gross total resection of a WHO grade I falcine and superior sagittal sinus secretory meningioma with extradural and bone extension and cranioplasty with a titanium mesh who had a recurrence 4 years later as two tumour masses on top of the titanium mesh with no adjacent soft tissue invasion, and without dural involvement. To our knowledge, this is the first reported case of meningioma growth on top of titanium cranioplasty material. Seeded or incompletely removed tumoral cells might have exploited the biocompatibility of titanium to promote tumour regrowth.

12.
Nucleic Acids Res ; 49(20): 11986-12001, 2021 11 18.
Article in English | MEDLINE | ID: mdl-34669958

ABSTRACT

Prime editing is a recent precision genome editing modality whose versatility offers the prospect for a wide range of applications, including the development of targeted genetic therapies. Yet, an outstanding bottleneck for its optimization and use concerns the difficulty in delivering large prime editing complexes into cells. Here, we demonstrate that packaging prime editing constructs in adenoviral capsids overcomes this constrain resulting in robust genome editing in both transformed and non-transformed human cells with up to 90% efficiencies. Using this cell cycle-independent delivery platform, we found a direct correlation between prime editing activity and cellular replication and disclose that the proportions between accurate prime editing events and unwanted byproducts can be influenced by the target-cell context. Hence, adenovector particles permit the efficacious delivery and testing of prime editing reagents in human cells independently of their transformation and replication statuses. The herein integrated gene delivery and gene editing technologies are expected to aid investigating the potential and limitations of prime editing in numerous experimental settings and, eventually, in ex vivo or in vivo therapeutic contexts.


Subject(s)
Adenoviridae/genetics , Gene Editing/methods , Gene Transfer Techniques , Genetic Vectors/genetics , Gene Deletion , HEK293 Cells , HeLa Cells , Humans
13.
Front Cell Dev Biol ; 9: 616610, 2021.
Article in English | MEDLINE | ID: mdl-33644053

ABSTRACT

Endothelial-to-mesenchymal transition (EndMT) plays an important role in embryonic development and disease progression. Yet, how different members of the transforming growth factor-ß (TGF-ß) family regulate EndMT is not well understood. In the current study, we report that TGF-ß2, but not bone morphogenetic protein (BMP)9, triggers EndMT in murine endothelial MS-1 and 2H11 cells. TGF-ß2 strongly upregulates the transcription factor SNAIL, and the depletion of Snail is sufficient to abrogate TGF-ß2-triggered mesenchymal-like cell morphology acquisition and EndMT-related molecular changes. Although SLUG is not regulated by TGF-ß2, knocking out Slug also partly inhibits TGF-ß2-induced EndMT in 2H11 cells. Interestingly, in addition to SNAIL and SLUG, BMP9 stimulates inhibitor of DNA binding (ID) proteins. The suppression of Id1, Id2, or Id3 expression facilitated BMP9 in inducing EndMT and, in contrast, ectopic expression of ID1, ID2, or ID3 abrogated TGF-ß2-mediated EndMT. Altogether, our results show that SNAIL is critical and indispensable for TGF-ß2-mediated EndMT. Although SLUG is also involved in the EndMT process, it plays less of a crucial role in it. In contrast, ID proteins are essential for maintaining endothelial traits and repressing the function of SNAIL and SLUG during the EndMT process. These data suggest that the control over endothelial vs. mesenchymal cell states is determined, at least in part, by a balance between the expression of SNAIL/SLUG and ID proteins.

14.
Nucleic Acids Res ; 49(2): 1173-1198, 2021 01 25.
Article in English | MEDLINE | ID: mdl-33398349

ABSTRACT

RNA-guided nucleases (RGNs) based on CRISPR systems permit installing short and large edits within eukaryotic genomes. However, precise genome editing is often hindered due to nuclease off-target activities and the multiple-copy character of the vast majority of chromosomal sequences. Dual nicking RGNs and high-specificity RGNs both exhibit low off-target activities. Here, we report that high-specificity Cas9 nucleases are convertible into nicking Cas9D10A variants whose precision is superior to that of the commonly used Cas9D10A nickase. Dual nicking RGNs based on a selected group of these Cas9D10A variants can yield gene knockouts and gene knock-ins at frequencies similar to or higher than those achieved by their conventional counterparts. Moreover, high-specificity dual nicking RGNs are capable of distinguishing highly similar sequences by 'tiptoeing' over pre-existing single base-pair polymorphisms. Finally, high-specificity RNA-guided nicking complexes generally preserve genomic integrity, as demonstrated by unbiased genome-wide high-throughput sequencing assays. Thus, in addition to substantially enlarging the Cas9 nickase toolkit, we demonstrate the feasibility in expanding the range and precision of DNA knockout and knock-in procedures. The herein introduced tools and multi-tier high-specificity genome editing strategies might be particularly beneficial whenever predictability and/or safety of genetic manipulations are paramount.


Subject(s)
Bacterial Proteins/metabolism , CRISPR-Associated Protein 9/metabolism , CRISPR-Cas Systems , Deoxyribonuclease I/metabolism , Gene Editing/methods , Bacterial Proteins/genetics , Base Sequence , CRISPR-Associated Protein 9/genetics , Clone Cells , Deoxyribonuclease I/genetics , Gene Knock-In Techniques , Gene Knockout Techniques , Genes, Reporter , Genotyping Techniques , HEK293 Cells , HeLa Cells , Heterochromatin/genetics , High-Throughput Nucleotide Sequencing , Humans , Induced Pluripotent Stem Cells , Polymorphism, Genetic , RNA, Guide, Kinetoplastida/genetics , Recombinant Proteins/metabolism , Streptococcus pyogenes/enzymology , Substrate Specificity , Transfection
15.
J Inherit Metab Dis ; 44(1): 54-71, 2021 01.
Article in English | MEDLINE | ID: mdl-32510617

ABSTRACT

Genetic therapies based on gene addition have witnessed a variety of clinical successes and the first therapeutic products have been approved for clinical use. Moreover, innovative gene editing techniques are starting to offer new opportunities in which the mutations that underlie genetic diseases can be directly corrected in afflicted somatic cells. The toolboxes underpinning these DNA modifying technologies are expanding with great pace. Concerning the ongoing efforts for their implementation, viral vector-based gene delivery systems have acquired center-stage, providing new hopes for patients with inherited and acquired disorders. Specifically, the application of genetic therapies using viral vectors for the treatment of inborn metabolic disorders is growing and clinical applications are starting to appear. While the field has matured from the technology perspective and has yielded efficacious products, it is the perception of many stakeholders that from the regulatory side further developments are urgently needed. In this review, we summarize the features of state-of-the-art viral vector systems and the corresponding gene-centered therapies they seek to deliver. Moreover, a brief summary is also given on emerging gene editing approaches built on CRISPR-Cas9 nucleases and, more recently, nickases, including base editors and prime editors. Finally, we will point at some regulatory aspects that may deserve further attention for translating these technological developments into actual advanced therapy medicinal products (ATMPs).


Subject(s)
Gene Editing/trends , Genetic Therapy/trends , Animals , CRISPR-Cas Systems , Gene Editing/methods , Gene Transfer Techniques , Genetic Diseases, Inborn/therapy , Genetic Therapy/methods , Genetic Vectors , Humans , Viruses/genetics
16.
Thyroid ; 31(6): 922-932, 2021 06.
Article in English | MEDLINE | ID: mdl-33143569

ABSTRACT

Background: The risk of malignancy (RoM) of indeterminate thyroid nodules (ITNs) shows a high variability in interinstitutional cohorts. The RoM is partially associated with the cytological degree of atypia and the ultrasound (US) pattern. This study evaluated the cancer risk of ITNs by jointly considering the cytological subcategory and the American Thyroid Association (ATA)-based US risk classification. Methods: This study features a retrospective cohort from two Brazilian centers comprising 238 ITNs with confirmed outcomes. US classification, according to ATA-based guidelines, and cytological subcategorization were determined. The cytological subgroups were as follows: (1) nuclear atypia (NA) related to papillary thyroid carcinoma (PTC) but insufficient to categorize the cytology as suspicious for malignancy; (2) architectural atypia without NA (AA); (3) both architectural and nuclear atypia (ANA); (4) oncocytic pattern (OP) without NA; and (5) NA not related to PTC (NANP). NA was divided into three subgroups: nuclear size and shape, nuclear membrane appearance, and/or chromatin aspects. Results: The overall frequency of malignancy was 39.5%. Among the cytological subcategories, the highest RoM was related to the NA (43.9%) and to the ANA (43.5%), followed by AA (29.4%), and OP (9.4%). NA was positively and independently associated with cancer (odds ratio [OR]: 4.5; confidence interval [CI: 1.2-16.6]) as was the occurrence of ANA (OR 6.6 [CI 1.5-29.5]). AA and OP were not independently associated with cancer. Both ATA-based high- and intermediate-risk categories showed an independent association with cancer (OR 6.8 [CI 2.9-15.5] and OR: 2.6 [CI 1.1-5.8], respectively). ITNs with cytological findings of NA or ANA when combined with intermediate US patterns had RoM values of 47.5% and 56.7%, respectively. Both cytological subcategories, when combined with the ATA high-suspicion class reached an RoM >70%. The type of NA with the highest odds for cancer was related to the nuclear membrane (OR 11.5). Conclusions: The RoM of ITNs can reach almost 80% when both NA and ATA-based high-risk US features are present. The presence of such cytological features also increased the RoM in the ATA-based intermediate-risk US category. In addition, AA and OP were not independently related to higher cancer risk. These results strengthen the recommendations for combing cytological subcategorization and US risk classification in the workup for ITNs before the decision of a molecular testing, clinical observation, or diagnostic surgery.


Subject(s)
Thyroid Cancer, Papillary/epidemiology , Thyroid Neoplasms/epidemiology , Thyroid Nodule/diagnostic imaging , Thyroid Nodule/pathology , Adenocarcinoma, Follicular/diagnostic imaging , Adenocarcinoma, Follicular/epidemiology , Adenocarcinoma, Follicular/pathology , Adenoma, Oxyphilic/diagnostic imaging , Adenoma, Oxyphilic/epidemiology , Adenoma, Oxyphilic/pathology , Adult , Biopsy, Fine-Needle , Carcinoma, Neuroendocrine/diagnostic imaging , Carcinoma, Neuroendocrine/epidemiology , Carcinoma, Neuroendocrine/pathology , Cohort Studies , Female , Humans , Male , Middle Aged , Retrospective Studies , Risk Assessment , Societies, Medical , Thyroid Cancer, Papillary/diagnostic imaging , Thyroid Cancer, Papillary/pathology , Thyroid Neoplasms/diagnostic imaging , Thyroid Neoplasms/pathology , Thyroid Nodule/classification
17.
Front Neurosci ; 14: 838, 2020.
Article in English | MEDLINE | ID: mdl-32973430

ABSTRACT

Inherited retinal diseases encompass a highly heterogenous group of disorders caused by a wide range of genetic variants and with diverse clinical symptoms that converge in the common trait of retinal degeneration. Indeed, mutations in over 270 genes have been associated with some form of retinal degenerative phenotype. Given the immune privileged status of the eye, cell replacement and gene augmentation therapies have been envisioned. While some of these approaches, such as delivery of genes through recombinant adeno-associated viral vectors, have been successfully tested in clinical trials, not all patients will benefit from current advancements due to their underlying genotype or phenotypic traits. Gene editing arises as an alternative therapeutic strategy seeking to correct mutations at the endogenous locus and rescue normal gene expression. Hence, gene editing technologies can in principle be tailored for treating retinal degeneration. Here we provide an overview of the different gene editing strategies that are being developed to overcome the challenges imposed by the post-mitotic nature of retinal cell types. We further discuss their advantages and drawbacks as well as the hurdles for their implementation in treating retinal diseases, which include the broad range of mutations and, in some instances, the size of the affected genes. Although therapeutic gene editing is at an early stage of development, it has the potential of enriching the portfolio of personalized molecular medicines directed at treating genetic diseases.

18.
Eng. sanit. ambient ; 25(4): 583-596, jul.-ago. 2020. tab, graf
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1133804

ABSTRACT

RESUMO O objetivo deste estudo foi investigar as águas superficiais e os níveis foliares dos elementos-traço (Cu, Zn, Cd e Pb) da Avicennia schaueriana na área de proteção ambiental (APA) Tinharé-Boipeba, litoral sul da Bahia, com ênfase na relação entre a qualidade ambiental e o gerenciamento costeiro. Mensuraram-se in situ variáveis físico-químicas nas águas superficiais, e tomaram-se alíquotas para análises microbiológicas. Também foram coletadas folhas de árvores de mangue em nove estações amostrais. Realizou-se a leitura dos elementos-traço por espectrometria de absorção atômica com chama (F-AAS). As análises físico-químicas e microbiológicas das águas superficiais, ainda que preliminares, indicaram perda de qualidade e desafios ao saneamento, os quais merecem a atenção de autoridades sanitárias ou de saúde pública e consulta à comunidade para elaboração de soluções técnicas compatíveis com os usos da natureza e modos de vida tradicionais na APA. Os níveis foliares dos metais foram normais e não tóxicos, sendo menores do que em áreas costeiras impactadas. Os bosques de mangue encontram-se em bom estado de conservação e servem de área de referência, recomendando-se o monitoramento dos elementos-traço nas folhas ou sedimentos de mangue e qualidade da água. Esta pesquisa tem relevância à conservação dos manguezais, aos usos culturais da natureza e ao gerenciamento costeiro.


ABSTRACT The objective of this study was to investigate the surface waters and leaf levels of trace elements (Cu, Zn, Cd, and Pb) of the Avicennia schaueriana in the Tinharé-Boipeba Environmental Protection Area (APA), South Coast of Bahia, with emphasis to the relationship between environmental quality and coastal management. Physical-chemical variables were measured in situ in surface waters and aliquots were taken for microbiological analysis. Also, leaves of mangrove trees were collected at nine sampling stations. The trace element reading was performed by F-AAS. Physical-chemical and microbiological analyzes of surface water, although preliminary, indicated that there is a loss of quality and challenges to sanitation, which deserve the attention of sanitary authorities, and of public health, and consultation with the community to elaborate technical solutions compatible with the uses of nature and traditional lifestyles in APA. Leaf metal levels were normal and nontoxic, being lower than in impacted coastal areas. Mangrove forests are in good state of conservation and serve as a reference area, recommending the monitoring of trace elements in mangrove leaves or sediments and water quality. This research has relevance to the conservation of mangroves, cultural uses of nature and coastal management.

19.
Cells ; 9(4)2020 04 02.
Article in English | MEDLINE | ID: mdl-32252479

ABSTRACT

Duchenne muscular dystrophy (DMD) is a fatal X-linked muscle wasting disorder arising from mutations in the ~2.4 Mb dystrophin-encoding DMD gene. RNA-guided CRISPR-Cas9 nucleases (RGNs) are opening new DMD therapeutic routes whose bottlenecks include delivering sizable RGN complexes for assessing their effects on human genomes and testing ex vivo and in vivo DMD-correcting strategies. Here, high-capacity adenoviral vectors (HC-AdVs) encoding single or dual high-specificity RGNs with optimized components were investigated for permanently repairing defective DMD alleles either through exon 51-targeted indel formation or major mutational hotspot excision (>500 kb), respectively. Firstly, we establish that, at high doses, third-generation HC-AdVs lacking all viral genes are significantly less cytotoxic than second-generation adenoviral vectors deleted in E1 and E2A. Secondly, we demonstrate that genetically retargeted HC-AdVs can correct up to 42% ± 13% of defective DMD alleles in muscle cell populations through targeted removal of the major mutational hotspot, in which over 60% of frame-shifting large deletions locate. Both DMD gene repair strategies tested readily led to the detection of Becker-like dystrophins in unselected muscle cell populations, leading to the restoration of ß-dystroglycan at the plasmalemma of differentiated muscle cells. Hence, HC-AdVs permit the effective assessment of DMD gene-editing tools and strategies in dystrophin-defective human cells while broadening the gamut of DMD-correcting agents.


Subject(s)
Adenoviridae/genetics , Gene Editing/methods , Genetic Therapy/methods , Genetic Vectors/genetics , Muscular Dystrophy, Duchenne/genetics , Humans , Muscular Dystrophy, Duchenne/pathology
20.
Cells ; 9(4)2020 04 13.
Article in English | MEDLINE | ID: mdl-32295080

ABSTRACT

Gene editing permits changing specific DNA sequences within the vast genomes of human cells. Stem cells are particularly attractive targets for gene editing interventions as their self-renewal and differentiation capabilities consent studying cellular differentiation processes, screening small-molecule drugs, modeling human disorders, and testing regenerative medicines. To integrate gene editing and stem cell technologies, there is a critical need for achieving efficient delivery of the necessary molecular tools in the form of programmable DNA-targeting enzymes and/or exogenous nucleic acid templates. Moreover, the impact that the delivery agents themselves have on the performance and precision of gene editing procedures is yet another critical parameter to consider. Viral vectors consisting of recombinant replication-defective viruses are under intense investigation for bringing about efficient gene-editing tool delivery and precise gene-editing in human cells. In this review, we focus on the growing role that adenoviral vectors are playing in the targeted genetic manipulation of human stem cells, progenitor cells, and their differentiated progenies in the context of in vitro and ex vivo protocols. As preamble, we provide an overview on the main gene editing principles and adenoviral vector platforms and end by discussing the possibilities ahead resulting from leveraging adenoviral vector, gene editing, and stem cell technologies.


Subject(s)
Gene Editing/methods , Genetic Vectors/metabolism , Genomics/methods , Stem Cells/metabolism , Tissue Engineering/methods , Humans
SELECTION OF CITATIONS
SEARCH DETAIL
...