Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Avicenna J Phytomed ; 14(1): 138-141, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38948172

RESUMO

Objective: There is escalating evidence suggesting the beneficial effects of ellagic acid (EA) on the cardiovascular system. The aim of the present study was to investigate the protective effect of EA in human umbilical vein endothelial cells (HUVECs) against high glucose (HG)- induced endothelial dysfunction and to study the potential roles of adropin and nitric oxide (NO) in this regard. Materials and Methods: The experimental groups consisted of normal and HG (30 mM, 48 hr)-treated HUVECs incubated without or with 5 or 10 µM of EA (6 groups of at least 6 replicates, each). The cell count and viability were studied. Moreover, the markers of the redox state, including malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and catalase enzymes, and ferric reducing anti-oxidant power (FRAP), were assayed. The levels of adropin and eNOS gene expression were also studied using RT-qPCR. Results: A high concentration of glucose reduced cell count and caused lipid peroxidation, reduced anti-oxidant capacity of the cells, decreased NO levels, and downregulated the expression of NOS3 (encoding eNOS) and ENHO (encoding adropin) genes. Ellagic acid reversed all these effects. Conclusion: These results suggest a significant protective effect for EA against HG-induced injury in HUVECs. The improved redox state and upregulation of NOS3 and ENHO genes seem to play critical roles in this regard.

2.
Protein J ; 43(2): 316-332, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38145445

RESUMO

Most plant and bacterial toxins are highly immunogenic with non-specific toxic effects. Human ribonucleases are thought to provide a promising basis for reducing the toxic agent's immunogenic properties, which are candidates for cancer therapy. In the cell, the ribonuclease inhibitor (RI) protein binds to the ribonuclease enzyme and forms a tight complex. This study aimed to engineer and provide a gene construct encoding an improved version of Human Pancreatic RNase 1 (HP-RNase 1) to reduce connection to RI and modulate the immunogenic effects of immunotoxins. To further characterize the interaction complex of HP-RNase 1 and RI, we established various in silico and in vitro approaches. These methods allowed us to specifically monitor interactions within native and engineered HP-RNase 1/RI complexes. In silico research involved molecular dynamics (MD) simulations of native and mutant HP-RNase 1 in their free form and when bound to RI. For HP-RNase 1 engineering, we designed five mutations (K8A/N72A/N89A/R92D/E112/A) based on literature studies, as this combination proved effective for the intended investigation. Then, the cDNA encoding HP-RNase 1 was generated by RT-PCR from blood and cloned into the pSYN2 expression vector. Consequently, wild-type and the engineered HP-RNase 1 were over-expressed in E. coli TG1 and purified using an IMAC column directed against a poly-his tag. The protein products were detected by SDS-PAGE and Western blot analysis. HP-RNase 1 catalytic activity, in the presence of various concentrations of RI, demonstrated that the mutated version of the protein is able to escape the ribonuclease inhibitor and target the RNA substrate 2.5 folds more than that of the wild type. From these data, we tend to suggest the engineered recombinant HP-RNase 1 potentially as a new immunotherapeutic agent for application in human cancer therapy.


Assuntos
Proteínas de Transporte , Simulação de Dinâmica Molecular , Engenharia de Proteínas , Ribonuclease Pancreático , Humanos , Engenharia de Proteínas/métodos , Ribonuclease Pancreático/química , Ribonuclease Pancreático/genética , Ribonuclease Pancreático/metabolismo , Neoplasias/terapia , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/tratamento farmacológico , Imunoterapia/métodos , Escherichia coli/genética , Proteínas Recombinantes/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Imunotoxinas/química , Imunotoxinas/genética , Imunotoxinas/farmacologia , Mutação
3.
Mol Biol Rep ; 50(10): 8589-8601, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37644368

RESUMO

BACKGROUND: We aimed to evaluate the various clinicopathodemographical, epidemiological, and molecular contributors to cumulatively worldwide metastatic colorectal cancer (CRC) in CRC patients from a highly populated area in northeastern Iran to pinpoint metastasis risk. METHODS: A retrospective clinical material-based cohort including a total of 6260 registered CRC patients, of whom 3829 underwent surgery, from regional university hospitals, during 2006-2016, were analyzed for the clinicopathodemographical aspects of age, sex, stage of CRC, history of smoking, type 2 diabetes (T2D), hypertension, body mass index (BMI), familial/occupational status, post-surgery survival period and mRNA/protein expression of mucin stabilizer (B3GALNT2), mucin I (MUC1), key cell cycle molecules (i.e., P53 and Ki67), and MMR-related genes. Factors were set to estimate the risk of metastatic CRC and mortality. RESULTS: Predominant adenocarcinomatous CRCs were found in colon. Post-surgery survival period of metastatic CRC patients was remarkably longer in patients aged > 50 compared to those aged < 50 years, and worse in females than males. B3GALNT2high, MUChigh, P53low, and Ki67high mRNA/protein expression in the metastatic stage III CRC along with T2D and hypertension were associated with increased metastasis/mortality, with more worsening in males, older, BMI > 25, urban residing, and employed individuals, indicative of non-genetic attributable factors. CONCLUSION: B3GALNT2, MUC1, and "Ki67" can be used as promising biomarkers for prognosis and early diagnosis of increasingly/predominantly non-genetic/environmental originated metastatic CRCs.


Assuntos
Neoplasias do Colo , Neoplasias Colorretais , Diabetes Mellitus Tipo 2 , N-Acetilgalactosaminiltransferases , Feminino , Masculino , Humanos , Mucinas/genética , Antígeno Ki-67/genética , Estudos Retrospectivos , Proteína Supressora de Tumor p53 , Ciclo Celular , Neoplasias Colorretais/genética
4.
J Biol Eng ; 17(1): 46, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37461059

RESUMO

BACKGROUND: Hormone-dependent promoters are very efficient in transgene expression. Plasmid-based reporter assays have identified regulatory sequences of the Ovalbumin promoter that are involved in response to estrogen and have shown that the deletion of the steroid-dependent regulatory element (SDRE) and negative regulatory element (NRE) leads to a steroid-independent expression of a reporter. However, the functional roles of these regulatory elements within the native genomic context of the Ovalbumin promoter have not been evaluated. RESULTS: In this study, we show that the negative effects of the NRE element on the Ovalbumin gene can be counteracted by CRISPR interference. We also show that the CRISPR-mediated deletion of SDRE and NRE promoter elements in a non-oviduct cell can lead to the significant expression of the Ovalbumin gene. In addition, the targeted knock-in of a transgene reporter in the Ovalbumin coding region and its expression confirms that the truncated promoter of the Ovalbumin gene can be efficiently used for an estrogen-independent expression of a foreign gene. CONCLUSIONS: The methodology applied in this paper allowed the study of promoter regulatory sequences in their native nuclear organization.

5.
Sci Rep ; 13(1): 12323, 2023 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-37516783

RESUMO

The cultivation and expansion of chicken primordial germ cells (cPGCs) are of critical importance for both biotechnological applications and the management of poultry genetic biodiversity. The feeder-free culture system has become the most popular approach for the cultivation and expansion of cPGCs. However, despite some success in the cultivation of cPGCs, the reproducibility of culture conditions across different laboratories remains a challenge. This study aimed to compare two defined and enriched media for the growth of cPGCs originating from the Hubbard JA57 broiler. To this end, cPGCs were isolated from the embryonic blood of Hamburger-Hamilton (HH) stages 14-16 and cultured at various time points. The Growth properties and characteristics of these cells were evaluated in two different culture conditions (the defined or enriched medium) and their migratory properties were assessed after genetic engineering and injection into the vasculature of 2.5-day-old chicken embryos. The main finding of this study was that the use of an enriched medium (the defined medium with Knock-Out Serum Replacement; KOSR) resulted in improved growth properties of cPGCs originating from the Hubbard JA57 broiler compared to a defined medium. The ability to cultivate and expand cPGCs is crucial for the generation of both genetically engineered birds and breeds of interest from local or commercial origins. Therefore, these results highlight the importance of choosing an appropriate culture medium for cPGCs growth and expansion.


Assuntos
Galinhas , Células Germinativas , Animais , Embrião de Galinha , Reprodutibilidade dos Testes , Biodiversidade , Biotecnologia
6.
Biol Proced Online ; 25(1): 18, 2023 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-37355580

RESUMO

BACKGROUND: One of the most prominent questions in the field of transgenesis is 'Where in the genome to integrate a transgene?'. Escape from epigenetic silencing and promoter shutdown of the transgene needs reliable genomic safe harbor (GSH) loci. Advances in genome engineering technologies combined with multi-omics bioinformatics data have enabled rational evaluation of GSH loci in the host genome. Currently, no validated GSH loci have been evaluated in the chicken genome. RESULTS: Here, we analyzed and experimentally examined two GSH loci in the genome of chicken cells. To this end, putative GSH loci including chicken HIPP-like (cHIPP; between DRG1 and EIF4ENIF1 genes) and chicken ROSA-like (cROSA; upstream of the THUMPD3 gene) were predicted using multi-omics bioinformatics data. Then, the durable expression of the transgene was validated by experimental characterization of continuously-cultured isogenous cell clones harboring DsRed2-ΔCMV-EGFP cassette in the predicted loci. The weakened form of the CMV promoter (ΔCMV) allowed the precise evaluation of GSH loci in a locus-dependent manner compared to the full-length CMV promoter. CONCLUSIONS: cHIPP and cROSA loci introduced in this study can be reliably exploited for consistent bio-manufacturing of recombinant proteins in the genetically-engineered chickens. Also, results showed that the genomic context dictates the expression of transgene controlled by ΔCMV in GSH loci.

7.
Comp Immunol Microbiol Infect Dis ; 97: 101984, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37119594

RESUMO

This study was designed to evaluate the safety, immunogenicity, and efficacy of a single dose of L. infantum (LiCen-/-) live attenuated candidate vaccine against canine leishmaniasis (CanL). Eighteen healthy domestic dogs with no anti-Leishmania antibodies and negative leishmanin skin test (LST) were randomly inoculated intravenously with either L. infantum (LiCen-/-) vaccine candidate in 10 dogs or phosphate-buffered saline (PBS) in 8 dogs. The safety, immunogenicity, and efficacy rate of L. infantum (LiCen-/-) vaccine candidate against CanL were evaluated by different criteria, including clinical manifestations, injection-site lesion, hematology and biochemistry values, anti-Leishmania antibodies using direct agglutination test (DAT), delayed-type hypersensitivity (DTH) using LST, and CD4+ and CD8+ T-cells subsets, as well as by measuring interferon (IFN-γ), interleukin (IL-23), IL-17, and IL-10 cytokines. Spleen aspiration and detection of Leishmania parasite using parasitological examinations (microscopy and culture) were performed in both vaccinated and control groups. Two months after intervention, each dog was challenged intraperitoneally (IP) with wide type (WT) L. infantum. Two-month follow-up post vaccination showed no clinical signs and serious side effects associated with the vaccination. A significant increase was found in the expression of IL-17, CD4+, and CD8+ gene transcripts in PBMCs, as well as increased levels of Th1 cytokines, and reduction of Th2 cytokine. The efficacy of the vaccine candidate was calculated to be 42.85%. While the time window for assessing the vaccine's effectiveness was too limited to draw any real conclusions but the preliminary results showed a moderate efficacy rate due to inoculation a single dose of L. infantum (LiCen-/-) vaccine candidate. Further investigations with more sample sizes and multiple doses of the vaccine candidate using natural challenges in the endemic areas of CanL are recommended.


Assuntos
Doenças do Cão , Leishmania infantum , Vacinas contra Leishmaniose , Leishmaniose Visceral , Leishmaniose , Animais , Cães , Leishmaniose Visceral/prevenção & controle , Leishmaniose Visceral/veterinária , Leishmaniose Visceral/diagnóstico , Interleucina-17 , Combinação Trimetoprima e Sulfametoxazol , Linfócitos T CD8-Positivos , Citocinas/metabolismo , Leishmaniose/veterinária , Vacinas Atenuadas , Doenças do Cão/parasitologia
8.
Work ; 75(3): 1059-1069, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36057811

RESUMO

BACKGROUND: Mines are often home to many dangers with a high rate of accidents and occupational diseases. One of the most effective ways to prevent these adverse incidents is to identify and control the influential factors causing human error in design and the ensuing negative consequences. OBJECTIVE: This study aimed to explore, categorize and prioritize factors affecting human errors in the mine design process. METHODS: The study has a mixed-method design combining qualitative and quantitative data. In the qualitative phase, the required data were collected by conducting semi-structured interviews with 12 surface mine designers. The causes of errors were extracted and categorized by the latent content analysis using MAXQDA2022 software. The identified causes in the qualitative phase were sent to expert designers in Q tables, and the data were analyzed by factor analysis. RESULTS: Of the identified codes in the qualitative phase, 40 main themes in five different categories (individual, organizational, external, task, and environmental factors) were determined as causes. The results of the quantitative phase suggest the existence of four different mental patterns regarding the causes of design errors (DEs). The data analysis also shows that organizational and personal factors, particularly supervision and inspection, experience, and technical knowledge, were the strongest causes of DEs and environmental (hotness, coldness, indoor air quality, and noise) and external (work-family conflict) factors being the weakest ones. CONCLUSION: This study not only identifies and categorizes the causes of design errors in the mining industry but also suggests some control strategies for these errors based on the mental patterns of the experts.


Assuntos
Doenças Profissionais , Humanos , Mineração , Pesquisa Qualitativa
10.
Sci Rep ; 12(1): 3390, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35232993

RESUMO

Various methods have been used in targeted gene knock-in applications. CRISPR-based knock-in strategies based on homology-independent repair pathways such as CRISPR HITI have been shown to possess the best efficiency for gene knock-in in mammalian cells. However, these methods suffer from the probability of plasmid backbone insertion at the target site. On the other hand, studies trying to combine the targeting ability of the Cas9 molecule and the excision/integration capacity of the PB transposase have shown random integrations. In this study, we introduce a new homology-independent knock-in strategy, Transposase-CRISPR mediated Targeted Integration (TransCRISTI), that exploits a fusion of Cas9 nuclease and a double mutant piggyBac transposase. In isogenic mammalian cell lines, we show that the TransCRISTI method demonstrates higher efficiency (72%) for site-specific insertions than the CRISPR HITI (44%) strategy. Application of the TransCRISTI method resulted in site-directed integration in 4.13% and 3.69% of the initially transfected population in the human AAVS1and PML loci, respectively, while the CRISPR HITI strategy resulted in site-directed integration in the PML locus in only 0.6% of cells. We also observed lower off-target and random insertions in the TransCRISTI group than the CRISPR HITI group. The TransCRISTI technology represents a great potential for the accurate and high-efficiency knock-in of the desired transposable elements into the predetermined genomic locations.


Assuntos
Genoma Humano , Transposases , Animais , Sistemas CRISPR-Cas , Edição de Genes/métodos , Técnicas de Introdução de Genes , Humanos , Mamíferos/metabolismo , Plasmídeos , Transposases/genética , Transposases/metabolismo
11.
Life Sci ; 295: 120409, 2022 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-35182556

RESUMO

Various DNA breaks created via programmable CRISPR/Cas9 nuclease activity results in different intracellular DNA break repair pathways. Based on the cellular repair pathways, CRISPR-based gene knock-in methods can be categorized into two major strategies: 1) Homology-independent strategies which are targeted insertion events based on non-homologous end joining, and 2) Homology-dependent strategies which are targeted insertion events based on the homology-directed repair. This review elaborates on various gene knock-in methods in mammalian cells using the CRISPR/Cas9 system and in sync with DNA-break repair pathways. Gene knock-in methods are applied in functional genomics and gene therapy. To compensate or correct genetic defects, different CRISPR-based gene knock-in strategies can be used. Thus, researchers need to make a conscious decision about the most suitable knock-in method. For a successful gene-targeted insertion, some determinant factors should be considered like cell cycle, dominant DNA repair pathway, size of insertions, and donor properties. In this review, different aspects of each gene knock-in strategy are discussed to provide a framework for choosing the most appropriate gene knock-in method in different applications.


Assuntos
Reparo do DNA/genética , Reparo do DNA/fisiologia , Técnicas de Introdução de Genes/métodos , Animais , Sistemas CRISPR-Cas/genética , Sistemas CRISPR-Cas/fisiologia , DNA/química , DNA/metabolismo , Quebras de DNA/efeitos dos fármacos , Reparo do DNA por Junção de Extremidades/genética , Edição de Genes/métodos , Humanos , Reparo de DNA por Recombinação/genética
12.
Biol Reprod ; 106(1): 24-46, 2022 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-34668968

RESUMO

Generating biopharmaceuticals in genetically engineered bioreactors continues to reign supreme. Hence, genetically engineered birds have attracted considerable attention from the biopharmaceutical industry. Fairly recent genome engineering methods have made genome manipulation an easy and affordable task. In this review, we first provide a broad overview of the approaches and main impediments ahead of generating efficient and reliable genetically engineered birds, and various factors that affect the fate of a transgene. This section provides an essential background for the rest of the review, in which we discuss and compare different genome manipulation methods in the pre-clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR era in the field of avian genome engineering.


Assuntos
Aves/genética , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Engenharia Genética/veterinária , Animais , Animais Geneticamente Modificados , Produtos Biológicos , Feminino , Técnicas de Introdução de Genes/métodos , Técnicas de Transferência de Genes/tendências , Técnicas de Transferência de Genes/veterinária , Engenharia Genética/métodos , Vetores Genéticos , Masculino , Espermatozoides
13.
Vet Res Forum ; 13(4): 521-527, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36686882

RESUMO

Stage X is one of the formation stages in birds at which the blastoderm area is distinguished by two areas of area pellucida being responsible for formation of embryonic tissues and primordial germ cells, and area opaca forming the extra-embryonic tissues. Primordial germ cells are multi-potent stem cells giving rise to spermatogonia or oogonia. The present study was carried out to describe the characteristics of primordial germ cells in stage X of pheasants' embryo using a transmission electron microscope. The blastoderm was dissected out from embryos which were already incubated for 12 hr. Toluidine blue was used for staining semi-thin sections; lead citrate and uranyl acetate were also used to stain ultra-thin sections. Images of primordial germ cells elucidated that the nucleus was situated eccentrically and had a compact spherical structure. Moreover, the nucleolus appeared elongated and was located eccentrically. The cytoplasm was composed of yolk granules and glycogen particles. Mitochondria were observed as round structures in the cytoplasm. The most important finding was that the primordial germ cells contained yolk granules, mitochondria and small amount of glycogen at this stage.

14.
Regen Med ; 16(12): 1037-1050, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34852636

RESUMO

Aim: To evaluate the suitability of using aorta elastin scaffold, in combination with human adipose-derived mesenchymal stem cells (hAd-MSCs), as an approach for cardiovascular tissue engineering. Materials & Methods: Human adipose-derived MSCs were seeded on elastin samples of decellularized bovine aorta. The samples were cultured in vitro to investigate the inductive effects of this scaffold on the cells. The results were evaluated using histological, and immunohistochemical methods, as well as MTT assay, DNA content, reverse transcription-PCR and scanning electron microscopy. Results: Histological staining and DNA content confirmed the efficacy of decellularization procedure (82% DNA removal). MTT assay showed the construct's ability to support cell viability and proliferation. Cell differentiation was confirmed by reverse transcription-PCR and positive immunohistochemistry for alfa smooth muscle actin and von Willebrand. Conclusion: The prepared aortic elastin samples act as a potential scaffold, in combination with MSCs, for applications in cardiovascular tissue engineering. Further experiments in animal models are required to confirm this.


Assuntos
Células-Tronco Mesenquimais , Engenharia Tecidual , Animais , Aorta , Bovinos , Elastina , Matriz Extracelular , Humanos , Alicerces Teciduais
15.
Sci Rep ; 11(1): 19851, 2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34615923

RESUMO

Introducing bacteriophage MS2 virus-like particles (VLPs) as gene and drug delivery tools increases the demand for optimizing their production and purification procedure. PEG precipitation method is used efficiently to purify VLPs, while the effects of pH and different electrolytes on the stability, size, and homogeneity of purified MS2 VLPs, and the encapsulated RNA sequences remained to be elucidated. In this regard, a vector, capable of producing VLP with an shRNA packed inside was prepared. The resulting VLPs in different buffers/solutions were assessed for their size, polydispersity index, and ability to protect the enclosed shRNA. We report that among Tris, HEPES, and PBS, with or without NaNO3, and also NaNO3 alone in different pH and ionic concentrations, the 100 mM NaNO3-Tris buffer with pH:8 can be used as a new and optimal MS2 VLP production buffer, capable of inhibiting the VLPs aggregation. These VLPs show a size range of 27-30 nm and suitable homogeneity with minimum 12-month stability at 4 °C. Moreover, the resulting MS2 VLPs were highly efficient and stable for at least 48 h in conditions similar to in vivo. These features of MS2 VLPs produced in the newly introduced buffer make them an appropriate candidate for therapeutic agents' delivery.


Assuntos
Levivirus/isolamento & purificação , Levivirus/fisiologia , Vírion/isolamento & purificação , Vírion/fisiologia , Soluções Tampão , Linhagem Celular , Fracionamento Químico/métodos , Humanos , Concentração de Íons de Hidrogênio , Levivirus/ultraestrutura , Nitratos/química , Tamanho da Partícula , Vírion/ultraestrutura
16.
Obes Res Clin Pract ; 15(5): 499-505, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34474970

RESUMO

BACKGROUND AND OBJECTIVE: The problem of obesity and its related complications are adversely affecting human society. We studied the effects of gassericin A, a bacteriocin produced by the intestinal bacteria, on adipocyte differentiation and development. DESIGN: Gassericin A was purified from Lactobacillus gasseri LA39 and was added to the culture medium of 3T3-L1 cells in two phases: Phase 1, 3T3-L1 cells were incubated with gassericin A while being induced to adipocytes (days 1-7); phase 2, the cells were incubated with the bacteriocin after being induced to adipocytes (days 8-12). The resultant changes in the pattern of expression of some of the important genes involved in adipogenesis were evaluated by RT-qPCR. The viability of cells and their numbers were also studied. RESULTS: In phase 1 of the study, the levels of transcripts for stearoyl CoA desaturase (SCD-1), zinc finger protein 423 (zfp-423), and glucose transporter 4 (GLUT4) genes were significantly reduced, while that of 422ap2 gene showed a significant increment (p < 0.05). In phase 2, the zfp-423 gene showed a reduction of expression and the 422ap2 gene showed an increase in expression (p < 0.05). The other genes including UCP-1 and TNF-α did not show any significant changes in neither of the groups. Gassericin A did not affect the morphology or viability of the cells, however, the numbers of cells had nearly doubled in the treatment groups. CONCLUSION: It seems that gassericin A could significantly alter the properties of adipocytes while they are in the process of development and after they have developed.


Assuntos
Adipócitos/efeitos dos fármacos , Bacteriocinas , Células 3T3-L1 , Adipogenia , Animais , Bacteriocinas/farmacologia , Diferenciação Celular , Camundongos , Obesidade/terapia
17.
Stem Cell Rev Rep ; 17(6): 2042-2053, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34181184

RESUMO

Chromatin is organized as chromosome territories in the nucleus of an interphase cell. The cell-type- and cell-state-specific organization of chromatin including the location, volume, compaction level, and spatial arrangement of chromosome territories are the major determinants of genome function. In addition, in response to different signaling stimuli and regulatory cues, it is the dynamic adaptation of chromatin structure that establishes and organizes transcriptional programs. It is known that varying levels of stemness are defined by gene regulatory networks. Accordingly, chromatin is the main milieu to host the transcriptional programs and gene regulatory networks responsible for the stemness status of a cell. In this review, our current understanding of the spatial organization of chromatin and the ways by which it defines stemness are discussed. In particular, the role of lncRNAs that regulate and affect chromatin organization and stemness properties are delineated. These roles can be categorized into the topics of specific binding to and epigenetic regulation of the promoter of pluripotency genes, their interaction with transcription factors, coordinating the intra- and inter-chromosomal looping of pluripotency-related genes, and their RNA-independent functions. This review brings together the results of studies that have begun to clarify the emerging roles of lncRNAs in the regulation of chromatin organization adapted for stemness and cancer plasticity.


Assuntos
RNA Longo não Codificante , Cromatina/genética , Epigênese Genética , Regiões Promotoras Genéticas , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Fatores de Transcrição/metabolismo
18.
FASEB J ; 35(2): e21359, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33496003

RESUMO

The ability and efficiency of targeted nucleases to perform sequence replacements or insertions into the genome are limited. This limited efficiency for sequence replacements or insertions can be explained by the dependency on DNA repair pathways, the possibility of cellular toxicity, and unwanted activation of proto-oncogenes. The piggyBac (PB) transposase uses a very efficient enzymatic mechanism to integrate DNA fragments into the genome in a random manner. In this study, we fused an RNA-guided catalytically inactive Cas9 (dCas9) to the PB transposase and used dual sgRNAs to localize this molecule to specific genomic targets. We designed and used a promoter/reporter complementation assay to register and recover cells harboring-specific integrations, where only by complementation upon correct genomic integration, the reporter can be activated. Using an RNA-guided piggyBac transposase and dual sgRNAs, we were able to achieve site-directed integrations in the human ROSA26 safe harbor region in 0.32% of cells. These findings show that the methodology used in this study can be used for targeting genomic regions. An application for this finding could be in cancer cells to insert sequences into specific target regions that are intended to be destroyed, or to place promoter cargos behind the tumor suppressor genes to activate them.


Assuntos
Sistemas CRISPR-Cas , Técnicas de Introdução de Genes/métodos , Proteína 9 Associada à CRISPR/metabolismo , Genes Reporter , Células HEK293 , Humanos , Mutagênese Insercional , RNA Guia de Cinetoplastídeos/metabolismo , Transposases/genética , Transposases/metabolismo
19.
Curr Pharm Biotechnol ; 22(7): 878-891, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32838715

RESUMO

In recent years, extensive attention has been given to the generation of new classes of ligand- specific binding proteins to supplement monoclonal antibodies. A combination of protein engineering and display technologies has been used to manipulate non-human antibodies for humanization and stabilization purposes or even the generation of new binding proteins. Engineered protein scaffolds can now be directed against therapeutic targets to treat cancer and immunological disorders. Although very few of these scaffolds have successfully passed clinical trials, their remarkable properties such as robust folding, high solubility, and small size motivate their employment as a tool for biology and applied science studies. Here, we have focused on the generation of new non-Ig binding proteins and single domain antibody manipulation, with a glimpse of their applications.


Assuntos
Proteínas de Transporte/síntese química , Proteínas de Transporte/genética , Engenharia de Proteínas/métodos , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/genética , Humanos , Biblioteca de Peptídeos , Ligação Proteica/fisiologia , Engenharia de Proteínas/tendências , Estrutura Secundária de Proteína
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...